Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
new file mode 100644
index 0000000..4825448
--- /dev/null
+++ b/drivers/ide/ide-tape.c
@@ -0,0 +1,4937 @@
+/*
+ * linux/drivers/ide/ide-tape.c Version 1.19 Nov, 2003
+ *
+ * Copyright (C) 1995 - 1999 Gadi Oxman <gadio@netvision.net.il>
+ *
+ * $Header$
+ *
+ * This driver was constructed as a student project in the software laboratory
+ * of the faculty of electrical engineering in the Technion - Israel's
+ * Institute Of Technology, with the guide of Avner Lottem and Dr. Ilana David.
+ *
+ * It is hereby placed under the terms of the GNU general public license.
+ * (See linux/COPYING).
+ */
+
+/*
+ * IDE ATAPI streaming tape driver.
+ *
+ * This driver is a part of the Linux ide driver and works in co-operation
+ * with linux/drivers/block/ide.c.
+ *
+ * The driver, in co-operation with ide.c, basically traverses the
+ * request-list for the block device interface. The character device
+ * interface, on the other hand, creates new requests, adds them
+ * to the request-list of the block device, and waits for their completion.
+ *
+ * Pipelined operation mode is now supported on both reads and writes.
+ *
+ * The block device major and minor numbers are determined from the
+ * tape's relative position in the ide interfaces, as explained in ide.c.
+ *
+ * The character device interface consists of the following devices:
+ *
+ * ht0 major 37, minor 0 first IDE tape, rewind on close.
+ * ht1 major 37, minor 1 second IDE tape, rewind on close.
+ * ...
+ * nht0 major 37, minor 128 first IDE tape, no rewind on close.
+ * nht1 major 37, minor 129 second IDE tape, no rewind on close.
+ * ...
+ *
+ * Run linux/scripts/MAKEDEV.ide to create the above entries.
+ *
+ * The general magnetic tape commands compatible interface, as defined by
+ * include/linux/mtio.h, is accessible through the character device.
+ *
+ * General ide driver configuration options, such as the interrupt-unmask
+ * flag, can be configured by issuing an ioctl to the block device interface,
+ * as any other ide device.
+ *
+ * Our own ide-tape ioctl's can be issued to either the block device or
+ * the character device interface.
+ *
+ * Maximal throughput with minimal bus load will usually be achieved in the
+ * following scenario:
+ *
+ * 1. ide-tape is operating in the pipelined operation mode.
+ * 2. No buffering is performed by the user backup program.
+ *
+ * Testing was done with a 2 GB CONNER CTMA 4000 IDE ATAPI Streaming Tape Drive.
+ *
+ * Ver 0.1 Nov 1 95 Pre-working code :-)
+ * Ver 0.2 Nov 23 95 A short backup (few megabytes) and restore procedure
+ * was successful ! (Using tar cvf ... on the block
+ * device interface).
+ * A longer backup resulted in major swapping, bad
+ * overall Linux performance and eventually failed as
+ * we received non serial read-ahead requests from the
+ * buffer cache.
+ * Ver 0.3 Nov 28 95 Long backups are now possible, thanks to the
+ * character device interface. Linux's responsiveness
+ * and performance doesn't seem to be much affected
+ * from the background backup procedure.
+ * Some general mtio.h magnetic tape operations are
+ * now supported by our character device. As a result,
+ * popular tape utilities are starting to work with
+ * ide tapes :-)
+ * The following configurations were tested:
+ * 1. An IDE ATAPI TAPE shares the same interface
+ * and irq with an IDE ATAPI CDROM.
+ * 2. An IDE ATAPI TAPE shares the same interface
+ * and irq with a normal IDE disk.
+ * Both configurations seemed to work just fine !
+ * However, to be on the safe side, it is meanwhile
+ * recommended to give the IDE TAPE its own interface
+ * and irq.
+ * The one thing which needs to be done here is to
+ * add a "request postpone" feature to ide.c,
+ * so that we won't have to wait for the tape to finish
+ * performing a long media access (DSC) request (such
+ * as a rewind) before we can access the other device
+ * on the same interface. This effect doesn't disturb
+ * normal operation most of the time because read/write
+ * requests are relatively fast, and once we are
+ * performing one tape r/w request, a lot of requests
+ * from the other device can be queued and ide.c will
+ * service all of them after this single tape request.
+ * Ver 1.0 Dec 11 95 Integrated into Linux 1.3.46 development tree.
+ * On each read / write request, we now ask the drive
+ * if we can transfer a constant number of bytes
+ * (a parameter of the drive) only to its buffers,
+ * without causing actual media access. If we can't,
+ * we just wait until we can by polling the DSC bit.
+ * This ensures that while we are not transferring
+ * more bytes than the constant referred to above, the
+ * interrupt latency will not become too high and
+ * we won't cause an interrupt timeout, as happened
+ * occasionally in the previous version.
+ * While polling for DSC, the current request is
+ * postponed and ide.c is free to handle requests from
+ * the other device. This is handled transparently to
+ * ide.c. The hwgroup locking method which was used
+ * in the previous version was removed.
+ * Use of new general features which are provided by
+ * ide.c for use with atapi devices.
+ * (Programming done by Mark Lord)
+ * Few potential bug fixes (Again, suggested by Mark)
+ * Single character device data transfers are now
+ * not limited in size, as they were before.
+ * We are asking the tape about its recommended
+ * transfer unit and send a larger data transfer
+ * as several transfers of the above size.
+ * For best results, use an integral number of this
+ * basic unit (which is shown during driver
+ * initialization). I will soon add an ioctl to get
+ * this important parameter.
+ * Our data transfer buffer is allocated on startup,
+ * rather than before each data transfer. This should
+ * ensure that we will indeed have a data buffer.
+ * Ver 1.1 Dec 14 95 Fixed random problems which occurred when the tape
+ * shared an interface with another device.
+ * (poll_for_dsc was a complete mess).
+ * Removed some old (non-active) code which had
+ * to do with supporting buffer cache originated
+ * requests.
+ * The block device interface can now be opened, so
+ * that general ide driver features like the unmask
+ * interrupts flag can be selected with an ioctl.
+ * This is the only use of the block device interface.
+ * New fast pipelined operation mode (currently only on
+ * writes). When using the pipelined mode, the
+ * throughput can potentially reach the maximum
+ * tape supported throughput, regardless of the
+ * user backup program. On my tape drive, it sometimes
+ * boosted performance by a factor of 2. Pipelined
+ * mode is enabled by default, but since it has a few
+ * downfalls as well, you may want to disable it.
+ * A short explanation of the pipelined operation mode
+ * is available below.
+ * Ver 1.2 Jan 1 96 Eliminated pipelined mode race condition.
+ * Added pipeline read mode. As a result, restores
+ * are now as fast as backups.
+ * Optimized shared interface behavior. The new behavior
+ * typically results in better IDE bus efficiency and
+ * higher tape throughput.
+ * Pre-calculation of the expected read/write request
+ * service time, based on the tape's parameters. In
+ * the pipelined operation mode, this allows us to
+ * adjust our polling frequency to a much lower value,
+ * and thus to dramatically reduce our load on Linux,
+ * without any decrease in performance.
+ * Implemented additional mtio.h operations.
+ * The recommended user block size is returned by
+ * the MTIOCGET ioctl.
+ * Additional minor changes.
+ * Ver 1.3 Feb 9 96 Fixed pipelined read mode bug which prevented the
+ * use of some block sizes during a restore procedure.
+ * The character device interface will now present a
+ * continuous view of the media - any mix of block sizes
+ * during a backup/restore procedure is supported. The
+ * driver will buffer the requests internally and
+ * convert them to the tape's recommended transfer
+ * unit, making performance almost independent of the
+ * chosen user block size.
+ * Some improvements in error recovery.
+ * By cooperating with ide-dma.c, bus mastering DMA can
+ * now sometimes be used with IDE tape drives as well.
+ * Bus mastering DMA has the potential to dramatically
+ * reduce the CPU's overhead when accessing the device,
+ * and can be enabled by using hdparm -d1 on the tape's
+ * block device interface. For more info, read the
+ * comments in ide-dma.c.
+ * Ver 1.4 Mar 13 96 Fixed serialize support.
+ * Ver 1.5 Apr 12 96 Fixed shared interface operation, broken in 1.3.85.
+ * Fixed pipelined read mode inefficiency.
+ * Fixed nasty null dereferencing bug.
+ * Ver 1.6 Aug 16 96 Fixed FPU usage in the driver.
+ * Fixed end of media bug.
+ * Ver 1.7 Sep 10 96 Minor changes for the CONNER CTT8000-A model.
+ * Ver 1.8 Sep 26 96 Attempt to find a better balance between good
+ * interactive response and high system throughput.
+ * Ver 1.9 Nov 5 96 Automatically cross encountered filemarks rather
+ * than requiring an explicit FSF command.
+ * Abort pending requests at end of media.
+ * MTTELL was sometimes returning incorrect results.
+ * Return the real block size in the MTIOCGET ioctl.
+ * Some error recovery bug fixes.
+ * Ver 1.10 Nov 5 96 Major reorganization.
+ * Reduced CPU overhead a bit by eliminating internal
+ * bounce buffers.
+ * Added module support.
+ * Added multiple tape drives support.
+ * Added partition support.
+ * Rewrote DSC handling.
+ * Some portability fixes.
+ * Removed ide-tape.h.
+ * Additional minor changes.
+ * Ver 1.11 Dec 2 96 Bug fix in previous DSC timeout handling.
+ * Use ide_stall_queue() for DSC overlap.
+ * Use the maximum speed rather than the current speed
+ * to compute the request service time.
+ * Ver 1.12 Dec 7 97 Fix random memory overwriting and/or last block data
+ * corruption, which could occur if the total number
+ * of bytes written to the tape was not an integral
+ * number of tape blocks.
+ * Add support for INTERRUPT DRQ devices.
+ * Ver 1.13 Jan 2 98 Add "speed == 0" work-around for HP COLORADO 5GB
+ * Ver 1.14 Dec 30 98 Partial fixes for the Sony/AIWA tape drives.
+ * Replace cli()/sti() with hwgroup spinlocks.
+ * Ver 1.15 Mar 25 99 Fix SMP race condition by replacing hwgroup
+ * spinlock with private per-tape spinlock.
+ * Ver 1.16 Sep 1 99 Add OnStream tape support.
+ * Abort read pipeline on EOD.
+ * Wait for the tape to become ready in case it returns
+ * "in the process of becoming ready" on open().
+ * Fix zero padding of the last written block in
+ * case the tape block size is larger than PAGE_SIZE.
+ * Decrease the default disconnection time to tn.
+ * Ver 1.16e Oct 3 99 Minor fixes.
+ * Ver 1.16e1 Oct 13 99 Patches by Arnold Niessen,
+ * niessen@iae.nl / arnold.niessen@philips.com
+ * GO-1) Undefined code in idetape_read_position
+ * according to Gadi's email
+ * AJN-1) Minor fix asc == 11 should be asc == 0x11
+ * in idetape_issue_packet_command (did effect
+ * debugging output only)
+ * AJN-2) Added more debugging output, and
+ * added ide-tape: where missing. I would also
+ * like to add tape->name where possible
+ * AJN-3) Added different debug_level's
+ * via /proc/ide/hdc/settings
+ * "debug_level" determines amount of debugging output;
+ * can be changed using /proc/ide/hdx/settings
+ * 0 : almost no debugging output
+ * 1 : 0+output errors only
+ * 2 : 1+output all sensekey/asc
+ * 3 : 2+follow all chrdev related procedures
+ * 4 : 3+follow all procedures
+ * 5 : 4+include pc_stack rq_stack info
+ * 6 : 5+USE_COUNT updates
+ * AJN-4) Fixed timeout for retension in idetape_queue_pc_tail
+ * from 5 to 10 minutes
+ * AJN-5) Changed maximum number of blocks to skip when
+ * reading tapes with multiple consecutive write
+ * errors from 100 to 1000 in idetape_get_logical_blk
+ * Proposed changes to code:
+ * 1) output "logical_blk_num" via /proc
+ * 2) output "current_operation" via /proc
+ * 3) Either solve or document the fact that `mt rewind' is
+ * required after reading from /dev/nhtx to be
+ * able to rmmod the idetape module;
+ * Also, sometimes an application finishes but the
+ * device remains `busy' for some time. Same cause ?
+ * Proposed changes to release-notes:
+ * 4) write a simple `quickstart' section in the
+ * release notes; I volunteer if you don't want to
+ * 5) include a pointer to video4linux in the doc
+ * to stimulate video applications
+ * 6) release notes lines 331 and 362: explain what happens
+ * if the application data rate is higher than 1100 KB/s;
+ * similar approach to lower-than-500 kB/s ?
+ * 7) 6.6 Comparison; wouldn't it be better to allow different
+ * strategies for read and write ?
+ * Wouldn't it be better to control the tape buffer
+ * contents instead of the bandwidth ?
+ * 8) line 536: replace will by would (if I understand
+ * this section correctly, a hypothetical and unwanted situation
+ * is being described)
+ * Ver 1.16f Dec 15 99 Change place of the secondary OnStream header frames.
+ * Ver 1.17 Nov 2000 / Jan 2001 Marcel Mol, marcel@mesa.nl
+ * - Add idetape_onstream_mode_sense_tape_parameter_page
+ * function to get tape capacity in frames: tape->capacity.
+ * - Add support for DI-50 drives( or any DI- drive).
+ * - 'workaround' for read error/blank block around block 3000.
+ * - Implement Early warning for end of media for Onstream.
+ * - Cosmetic code changes for readability.
+ * - Idetape_position_tape should not use SKIP bit during
+ * Onstream read recovery.
+ * - Add capacity, logical_blk_num and first/last_frame_position
+ * to /proc/ide/hd?/settings.
+ * - Module use count was gone in the Linux 2.4 driver.
+ * Ver 1.17a Apr 2001 Willem Riede osst@riede.org
+ * - Get drive's actual block size from mode sense block descriptor
+ * - Limit size of pipeline
+ * Ver 1.17b Oct 2002 Alan Stern <stern@rowland.harvard.edu>
+ * Changed IDETAPE_MIN_PIPELINE_STAGES to 1 and actually used
+ * it in the code!
+ * Actually removed aborted stages in idetape_abort_pipeline
+ * instead of just changing the command code.
+ * Made the transfer byte count for Request Sense equal to the
+ * actual length of the data transfer.
+ * Changed handling of partial data transfers: they do not
+ * cause DMA errors.
+ * Moved initiation of DMA transfers to the correct place.
+ * Removed reference to unallocated memory.
+ * Made __idetape_discard_read_pipeline return the number of
+ * sectors skipped, not the number of stages.
+ * Replaced errant kfree() calls with __idetape_kfree_stage().
+ * Fixed off-by-one error in testing the pipeline length.
+ * Fixed handling of filemarks in the read pipeline.
+ * Small code optimization for MTBSF and MTBSFM ioctls.
+ * Don't try to unlock the door during device close if is
+ * already unlocked!
+ * Cosmetic fixes to miscellaneous debugging output messages.
+ * Set the minimum /proc/ide/hd?/settings values for "pipeline",
+ * "pipeline_min", and "pipeline_max" to 1.
+ *
+ * Here are some words from the first releases of hd.c, which are quoted
+ * in ide.c and apply here as well:
+ *
+ * | Special care is recommended. Have Fun!
+ *
+ */
+
+/*
+ * An overview of the pipelined operation mode.
+ *
+ * In the pipelined write mode, we will usually just add requests to our
+ * pipeline and return immediately, before we even start to service them. The
+ * user program will then have enough time to prepare the next request while
+ * we are still busy servicing previous requests. In the pipelined read mode,
+ * the situation is similar - we add read-ahead requests into the pipeline,
+ * before the user even requested them.
+ *
+ * The pipeline can be viewed as a "safety net" which will be activated when
+ * the system load is high and prevents the user backup program from keeping up
+ * with the current tape speed. At this point, the pipeline will get
+ * shorter and shorter but the tape will still be streaming at the same speed.
+ * Assuming we have enough pipeline stages, the system load will hopefully
+ * decrease before the pipeline is completely empty, and the backup program
+ * will be able to "catch up" and refill the pipeline again.
+ *
+ * When using the pipelined mode, it would be best to disable any type of
+ * buffering done by the user program, as ide-tape already provides all the
+ * benefits in the kernel, where it can be done in a more efficient way.
+ * As we will usually not block the user program on a request, the most
+ * efficient user code will then be a simple read-write-read-... cycle.
+ * Any additional logic will usually just slow down the backup process.
+ *
+ * Using the pipelined mode, I get a constant over 400 KBps throughput,
+ * which seems to be the maximum throughput supported by my tape.
+ *
+ * However, there are some downfalls:
+ *
+ * 1. We use memory (for data buffers) in proportional to the number
+ * of pipeline stages (each stage is about 26 KB with my tape).
+ * 2. In the pipelined write mode, we cheat and postpone error codes
+ * to the user task. In read mode, the actual tape position
+ * will be a bit further than the last requested block.
+ *
+ * Concerning (1):
+ *
+ * 1. We allocate stages dynamically only when we need them. When
+ * we don't need them, we don't consume additional memory. In
+ * case we can't allocate stages, we just manage without them
+ * (at the expense of decreased throughput) so when Linux is
+ * tight in memory, we will not pose additional difficulties.
+ *
+ * 2. The maximum number of stages (which is, in fact, the maximum
+ * amount of memory) which we allocate is limited by the compile
+ * time parameter IDETAPE_MAX_PIPELINE_STAGES.
+ *
+ * 3. The maximum number of stages is a controlled parameter - We
+ * don't start from the user defined maximum number of stages
+ * but from the lower IDETAPE_MIN_PIPELINE_STAGES (again, we
+ * will not even allocate this amount of stages if the user
+ * program can't handle the speed). We then implement a feedback
+ * loop which checks if the pipeline is empty, and if it is, we
+ * increase the maximum number of stages as necessary until we
+ * reach the optimum value which just manages to keep the tape
+ * busy with minimum allocated memory or until we reach
+ * IDETAPE_MAX_PIPELINE_STAGES.
+ *
+ * Concerning (2):
+ *
+ * In pipelined write mode, ide-tape can not return accurate error codes
+ * to the user program since we usually just add the request to the
+ * pipeline without waiting for it to be serviced. In case an error
+ * occurs, I will report it on the next user request.
+ *
+ * In the pipelined read mode, subsequent read requests or forward
+ * filemark spacing will perform correctly, as we preserve all blocks
+ * and filemarks which we encountered during our excess read-ahead.
+ *
+ * For accurate tape positioning and error reporting, disabling
+ * pipelined mode might be the best option.
+ *
+ * You can enable/disable/tune the pipelined operation mode by adjusting
+ * the compile time parameters below.
+ */
+
+/*
+ * Possible improvements.
+ *
+ * 1. Support for the ATAPI overlap protocol.
+ *
+ * In order to maximize bus throughput, we currently use the DSC
+ * overlap method which enables ide.c to service requests from the
+ * other device while the tape is busy executing a command. The
+ * DSC overlap method involves polling the tape's status register
+ * for the DSC bit, and servicing the other device while the tape
+ * isn't ready.
+ *
+ * In the current QIC development standard (December 1995),
+ * it is recommended that new tape drives will *in addition*
+ * implement the ATAPI overlap protocol, which is used for the
+ * same purpose - efficient use of the IDE bus, but is interrupt
+ * driven and thus has much less CPU overhead.
+ *
+ * ATAPI overlap is likely to be supported in most new ATAPI
+ * devices, including new ATAPI cdroms, and thus provides us
+ * a method by which we can achieve higher throughput when
+ * sharing a (fast) ATA-2 disk with any (slow) new ATAPI device.
+ */
+
+#define IDETAPE_VERSION "1.19"
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/timer.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/major.h>
+#include <linux/devfs_fs_kernel.h>
+#include <linux/errno.h>
+#include <linux/genhd.h>
+#include <linux/slab.h>
+#include <linux/pci.h>
+#include <linux/ide.h>
+#include <linux/smp_lock.h>
+#include <linux/completion.h>
+#include <linux/bitops.h>
+
+#include <asm/byteorder.h>
+#include <asm/irq.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+#include <asm/unaligned.h>
+
+/*
+ * partition
+ */
+typedef struct os_partition_s {
+ __u8 partition_num;
+ __u8 par_desc_ver;
+ __u16 wrt_pass_cntr;
+ __u32 first_frame_addr;
+ __u32 last_frame_addr;
+ __u32 eod_frame_addr;
+} os_partition_t;
+
+/*
+ * DAT entry
+ */
+typedef struct os_dat_entry_s {
+ __u32 blk_sz;
+ __u16 blk_cnt;
+ __u8 flags;
+ __u8 reserved;
+} os_dat_entry_t;
+
+/*
+ * DAT
+ */
+#define OS_DAT_FLAGS_DATA (0xc)
+#define OS_DAT_FLAGS_MARK (0x1)
+
+typedef struct os_dat_s {
+ __u8 dat_sz;
+ __u8 reserved1;
+ __u8 entry_cnt;
+ __u8 reserved3;
+ os_dat_entry_t dat_list[16];
+} os_dat_t;
+
+#include <linux/mtio.h>
+
+/**************************** Tunable parameters *****************************/
+
+
+/*
+ * Pipelined mode parameters.
+ *
+ * We try to use the minimum number of stages which is enough to
+ * keep the tape constantly streaming. To accomplish that, we implement
+ * a feedback loop around the maximum number of stages:
+ *
+ * We start from MIN maximum stages (we will not even use MIN stages
+ * if we don't need them), increment it by RATE*(MAX-MIN)
+ * whenever we sense that the pipeline is empty, until we reach
+ * the optimum value or until we reach MAX.
+ *
+ * Setting the following parameter to 0 is illegal: the pipelined mode
+ * cannot be disabled (calculate_speeds() divides by tape->max_stages.)
+ */
+#define IDETAPE_MIN_PIPELINE_STAGES 1
+#define IDETAPE_MAX_PIPELINE_STAGES 400
+#define IDETAPE_INCREASE_STAGES_RATE 20
+
+/*
+ * The following are used to debug the driver:
+ *
+ * Setting IDETAPE_DEBUG_INFO to 1 will report device capabilities.
+ * Setting IDETAPE_DEBUG_LOG to 1 will log driver flow control.
+ * Setting IDETAPE_DEBUG_BUGS to 1 will enable self-sanity checks in
+ * some places.
+ *
+ * Setting them to 0 will restore normal operation mode:
+ *
+ * 1. Disable logging normal successful operations.
+ * 2. Disable self-sanity checks.
+ * 3. Errors will still be logged, of course.
+ *
+ * All the #if DEBUG code will be removed some day, when the driver
+ * is verified to be stable enough. This will make it much more
+ * esthetic.
+ */
+#define IDETAPE_DEBUG_INFO 0
+#define IDETAPE_DEBUG_LOG 0
+#define IDETAPE_DEBUG_BUGS 1
+
+/*
+ * After each failed packet command we issue a request sense command
+ * and retry the packet command IDETAPE_MAX_PC_RETRIES times.
+ *
+ * Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
+ */
+#define IDETAPE_MAX_PC_RETRIES 3
+
+/*
+ * With each packet command, we allocate a buffer of
+ * IDETAPE_PC_BUFFER_SIZE bytes. This is used for several packet
+ * commands (Not for READ/WRITE commands).
+ */
+#define IDETAPE_PC_BUFFER_SIZE 256
+
+/*
+ * In various places in the driver, we need to allocate storage
+ * for packet commands and requests, which will remain valid while
+ * we leave the driver to wait for an interrupt or a timeout event.
+ */
+#define IDETAPE_PC_STACK (10 + IDETAPE_MAX_PC_RETRIES)
+
+/*
+ * Some drives (for example, Seagate STT3401A Travan) require a very long
+ * timeout, because they don't return an interrupt or clear their busy bit
+ * until after the command completes (even retension commands).
+ */
+#define IDETAPE_WAIT_CMD (900*HZ)
+
+/*
+ * The following parameter is used to select the point in the internal
+ * tape fifo in which we will start to refill the buffer. Decreasing
+ * the following parameter will improve the system's latency and
+ * interactive response, while using a high value might improve sytem
+ * throughput.
+ */
+#define IDETAPE_FIFO_THRESHOLD 2
+
+/*
+ * DSC polling parameters.
+ *
+ * Polling for DSC (a single bit in the status register) is a very
+ * important function in ide-tape. There are two cases in which we
+ * poll for DSC:
+ *
+ * 1. Before a read/write packet command, to ensure that we
+ * can transfer data from/to the tape's data buffers, without
+ * causing an actual media access. In case the tape is not
+ * ready yet, we take out our request from the device
+ * request queue, so that ide.c will service requests from
+ * the other device on the same interface meanwhile.
+ *
+ * 2. After the successful initialization of a "media access
+ * packet command", which is a command which can take a long
+ * time to complete (it can be several seconds or even an hour).
+ *
+ * Again, we postpone our request in the middle to free the bus
+ * for the other device. The polling frequency here should be
+ * lower than the read/write frequency since those media access
+ * commands are slow. We start from a "fast" frequency -
+ * IDETAPE_DSC_MA_FAST (one second), and if we don't receive DSC
+ * after IDETAPE_DSC_MA_THRESHOLD (5 minutes), we switch it to a
+ * lower frequency - IDETAPE_DSC_MA_SLOW (1 minute).
+ *
+ * We also set a timeout for the timer, in case something goes wrong.
+ * The timeout should be longer then the maximum execution time of a
+ * tape operation.
+ */
+
+/*
+ * DSC timings.
+ */
+#define IDETAPE_DSC_RW_MIN 5*HZ/100 /* 50 msec */
+#define IDETAPE_DSC_RW_MAX 40*HZ/100 /* 400 msec */
+#define IDETAPE_DSC_RW_TIMEOUT 2*60*HZ /* 2 minutes */
+#define IDETAPE_DSC_MA_FAST 2*HZ /* 2 seconds */
+#define IDETAPE_DSC_MA_THRESHOLD 5*60*HZ /* 5 minutes */
+#define IDETAPE_DSC_MA_SLOW 30*HZ /* 30 seconds */
+#define IDETAPE_DSC_MA_TIMEOUT 2*60*60*HZ /* 2 hours */
+
+/*************************** End of tunable parameters ***********************/
+
+/*
+ * Debugging/Performance analysis
+ *
+ * I/O trace support
+ */
+#define USE_IOTRACE 0
+#if USE_IOTRACE
+#include <linux/io_trace.h>
+#define IO_IDETAPE_FIFO 500
+#endif
+
+/*
+ * Read/Write error simulation
+ */
+#define SIMULATE_ERRORS 0
+
+/*
+ * For general magnetic tape device compatibility.
+ */
+typedef enum {
+ idetape_direction_none,
+ idetape_direction_read,
+ idetape_direction_write
+} idetape_chrdev_direction_t;
+
+struct idetape_bh {
+ unsigned short b_size;
+ atomic_t b_count;
+ struct idetape_bh *b_reqnext;
+ char *b_data;
+};
+
+/*
+ * Our view of a packet command.
+ */
+typedef struct idetape_packet_command_s {
+ u8 c[12]; /* Actual packet bytes */
+ int retries; /* On each retry, we increment retries */
+ int error; /* Error code */
+ int request_transfer; /* Bytes to transfer */
+ int actually_transferred; /* Bytes actually transferred */
+ int buffer_size; /* Size of our data buffer */
+ struct idetape_bh *bh;
+ char *b_data;
+ int b_count;
+ u8 *buffer; /* Data buffer */
+ u8 *current_position; /* Pointer into the above buffer */
+ ide_startstop_t (*callback) (ide_drive_t *); /* Called when this packet command is completed */
+ u8 pc_buffer[IDETAPE_PC_BUFFER_SIZE]; /* Temporary buffer */
+ unsigned long flags; /* Status/Action bit flags: long for set_bit */
+} idetape_pc_t;
+
+/*
+ * Packet command flag bits.
+ */
+/* Set when an error is considered normal - We won't retry */
+#define PC_ABORT 0
+/* 1 When polling for DSC on a media access command */
+#define PC_WAIT_FOR_DSC 1
+/* 1 when we prefer to use DMA if possible */
+#define PC_DMA_RECOMMENDED 2
+/* 1 while DMA in progress */
+#define PC_DMA_IN_PROGRESS 3
+/* 1 when encountered problem during DMA */
+#define PC_DMA_ERROR 4
+/* Data direction */
+#define PC_WRITING 5
+
+/*
+ * Capabilities and Mechanical Status Page
+ */
+typedef struct {
+ unsigned page_code :6; /* Page code - Should be 0x2a */
+ __u8 reserved0_6 :1;
+ __u8 ps :1; /* parameters saveable */
+ __u8 page_length; /* Page Length - Should be 0x12 */
+ __u8 reserved2, reserved3;
+ unsigned ro :1; /* Read Only Mode */
+ unsigned reserved4_1234 :4;
+ unsigned sprev :1; /* Supports SPACE in the reverse direction */
+ unsigned reserved4_67 :2;
+ unsigned reserved5_012 :3;
+ unsigned efmt :1; /* Supports ERASE command initiated formatting */
+ unsigned reserved5_4 :1;
+ unsigned qfa :1; /* Supports the QFA two partition formats */
+ unsigned reserved5_67 :2;
+ unsigned lock :1; /* Supports locking the volume */
+ unsigned locked :1; /* The volume is locked */
+ unsigned prevent :1; /* The device defaults in the prevent state after power up */
+ unsigned eject :1; /* The device can eject the volume */
+ __u8 disconnect :1; /* The device can break request > ctl */
+ __u8 reserved6_5 :1;
+ unsigned ecc :1; /* Supports error correction */
+ unsigned cmprs :1; /* Supports data compression */
+ unsigned reserved7_0 :1;
+ unsigned blk512 :1; /* Supports 512 bytes block size */
+ unsigned blk1024 :1; /* Supports 1024 bytes block size */
+ unsigned reserved7_3_6 :4;
+ unsigned blk32768 :1; /* slowb - the device restricts the byte count for PIO */
+ /* transfers for slow buffer memory ??? */
+ /* Also 32768 block size in some cases */
+ __u16 max_speed; /* Maximum speed supported in KBps */
+ __u8 reserved10, reserved11;
+ __u16 ctl; /* Continuous Transfer Limit in blocks */
+ __u16 speed; /* Current Speed, in KBps */
+ __u16 buffer_size; /* Buffer Size, in 512 bytes */
+ __u8 reserved18, reserved19;
+} idetape_capabilities_page_t;
+
+/*
+ * Block Size Page
+ */
+typedef struct {
+ unsigned page_code :6; /* Page code - Should be 0x30 */
+ unsigned reserved1_6 :1;
+ unsigned ps :1;
+ __u8 page_length; /* Page Length - Should be 2 */
+ __u8 reserved2;
+ unsigned play32 :1;
+ unsigned play32_5 :1;
+ unsigned reserved2_23 :2;
+ unsigned record32 :1;
+ unsigned record32_5 :1;
+ unsigned reserved2_6 :1;
+ unsigned one :1;
+} idetape_block_size_page_t;
+
+/*
+ * A pipeline stage.
+ */
+typedef struct idetape_stage_s {
+ struct request rq; /* The corresponding request */
+ struct idetape_bh *bh; /* The data buffers */
+ struct idetape_stage_s *next; /* Pointer to the next stage */
+} idetape_stage_t;
+
+/*
+ * REQUEST SENSE packet command result - Data Format.
+ */
+typedef struct {
+ unsigned error_code :7; /* Current of deferred errors */
+ unsigned valid :1; /* The information field conforms to QIC-157C */
+ __u8 reserved1 :8; /* Segment Number - Reserved */
+ unsigned sense_key :4; /* Sense Key */
+ unsigned reserved2_4 :1; /* Reserved */
+ unsigned ili :1; /* Incorrect Length Indicator */
+ unsigned eom :1; /* End Of Medium */
+ unsigned filemark :1; /* Filemark */
+ __u32 information __attribute__ ((packed));
+ __u8 asl; /* Additional sense length (n-7) */
+ __u32 command_specific; /* Additional command specific information */
+ __u8 asc; /* Additional Sense Code */
+ __u8 ascq; /* Additional Sense Code Qualifier */
+ __u8 replaceable_unit_code; /* Field Replaceable Unit Code */
+ unsigned sk_specific1 :7; /* Sense Key Specific */
+ unsigned sksv :1; /* Sense Key Specific information is valid */
+ __u8 sk_specific2; /* Sense Key Specific */
+ __u8 sk_specific3; /* Sense Key Specific */
+ __u8 pad[2]; /* Padding to 20 bytes */
+} idetape_request_sense_result_t;
+
+
+/*
+ * Most of our global data which we need to save even as we leave the
+ * driver due to an interrupt or a timer event is stored in a variable
+ * of type idetape_tape_t, defined below.
+ */
+typedef struct ide_tape_obj {
+ ide_drive_t *drive;
+ ide_driver_t *driver;
+ struct gendisk *disk;
+ struct kref kref;
+
+ /*
+ * Since a typical character device operation requires more
+ * than one packet command, we provide here enough memory
+ * for the maximum of interconnected packet commands.
+ * The packet commands are stored in the circular array pc_stack.
+ * pc_stack_index points to the last used entry, and warps around
+ * to the start when we get to the last array entry.
+ *
+ * pc points to the current processed packet command.
+ *
+ * failed_pc points to the last failed packet command, or contains
+ * NULL if we do not need to retry any packet command. This is
+ * required since an additional packet command is needed before the
+ * retry, to get detailed information on what went wrong.
+ */
+ /* Current packet command */
+ idetape_pc_t *pc;
+ /* Last failed packet command */
+ idetape_pc_t *failed_pc;
+ /* Packet command stack */
+ idetape_pc_t pc_stack[IDETAPE_PC_STACK];
+ /* Next free packet command storage space */
+ int pc_stack_index;
+ struct request rq_stack[IDETAPE_PC_STACK];
+ /* We implement a circular array */
+ int rq_stack_index;
+
+ /*
+ * DSC polling variables.
+ *
+ * While polling for DSC we use postponed_rq to postpone the
+ * current request so that ide.c will be able to service
+ * pending requests on the other device. Note that at most
+ * we will have only one DSC (usually data transfer) request
+ * in the device request queue. Additional requests can be
+ * queued in our internal pipeline, but they will be visible
+ * to ide.c only one at a time.
+ */
+ struct request *postponed_rq;
+ /* The time in which we started polling for DSC */
+ unsigned long dsc_polling_start;
+ /* Timer used to poll for dsc */
+ struct timer_list dsc_timer;
+ /* Read/Write dsc polling frequency */
+ unsigned long best_dsc_rw_frequency;
+ /* The current polling frequency */
+ unsigned long dsc_polling_frequency;
+ /* Maximum waiting time */
+ unsigned long dsc_timeout;
+
+ /*
+ * Read position information
+ */
+ u8 partition;
+ /* Current block */
+ unsigned int first_frame_position;
+ unsigned int last_frame_position;
+ unsigned int blocks_in_buffer;
+
+ /*
+ * Last error information
+ */
+ u8 sense_key, asc, ascq;
+
+ /*
+ * Character device operation
+ */
+ unsigned int minor;
+ /* device name */
+ char name[4];
+ /* Current character device data transfer direction */
+ idetape_chrdev_direction_t chrdev_direction;
+
+ /*
+ * Device information
+ */
+ /* Usually 512 or 1024 bytes */
+ unsigned short tape_block_size;
+ int user_bs_factor;
+ /* Copy of the tape's Capabilities and Mechanical Page */
+ idetape_capabilities_page_t capabilities;
+
+ /*
+ * Active data transfer request parameters.
+ *
+ * At most, there is only one ide-tape originated data transfer
+ * request in the device request queue. This allows ide.c to
+ * easily service requests from the other device when we
+ * postpone our active request. In the pipelined operation
+ * mode, we use our internal pipeline structure to hold
+ * more data requests.
+ *
+ * The data buffer size is chosen based on the tape's
+ * recommendation.
+ */
+ /* Pointer to the request which is waiting in the device request queue */
+ struct request *active_data_request;
+ /* Data buffer size (chosen based on the tape's recommendation */
+ int stage_size;
+ idetape_stage_t *merge_stage;
+ int merge_stage_size;
+ struct idetape_bh *bh;
+ char *b_data;
+ int b_count;
+
+ /*
+ * Pipeline parameters.
+ *
+ * To accomplish non-pipelined mode, we simply set the following
+ * variables to zero (or NULL, where appropriate).
+ */
+ /* Number of currently used stages */
+ int nr_stages;
+ /* Number of pending stages */
+ int nr_pending_stages;
+ /* We will not allocate more than this number of stages */
+ int max_stages, min_pipeline, max_pipeline;
+ /* The first stage which will be removed from the pipeline */
+ idetape_stage_t *first_stage;
+ /* The currently active stage */
+ idetape_stage_t *active_stage;
+ /* Will be serviced after the currently active request */
+ idetape_stage_t *next_stage;
+ /* New requests will be added to the pipeline here */
+ idetape_stage_t *last_stage;
+ /* Optional free stage which we can use */
+ idetape_stage_t *cache_stage;
+ int pages_per_stage;
+ /* Wasted space in each stage */
+ int excess_bh_size;
+
+ /* Status/Action flags: long for set_bit */
+ unsigned long flags;
+ /* protects the ide-tape queue */
+ spinlock_t spinlock;
+
+ /*
+ * Measures average tape speed
+ */
+ unsigned long avg_time;
+ int avg_size;
+ int avg_speed;
+
+ /* last sense information */
+ idetape_request_sense_result_t sense;
+
+ char vendor_id[10];
+ char product_id[18];
+ char firmware_revision[6];
+ int firmware_revision_num;
+
+ /* the door is currently locked */
+ int door_locked;
+ /* the tape hardware is write protected */
+ char drv_write_prot;
+ /* the tape is write protected (hardware or opened as read-only) */
+ char write_prot;
+
+ /*
+ * Limit the number of times a request can
+ * be postponed, to avoid an infinite postpone
+ * deadlock.
+ */
+ /* request postpone count limit */
+ int postpone_cnt;
+
+ /*
+ * Measures number of frames:
+ *
+ * 1. written/read to/from the driver pipeline (pipeline_head).
+ * 2. written/read to/from the tape buffers (idetape_bh).
+ * 3. written/read by the tape to/from the media (tape_head).
+ */
+ int pipeline_head;
+ int buffer_head;
+ int tape_head;
+ int last_tape_head;
+
+ /*
+ * Speed control at the tape buffers input/output
+ */
+ unsigned long insert_time;
+ int insert_size;
+ int insert_speed;
+ int max_insert_speed;
+ int measure_insert_time;
+
+ /*
+ * Measure tape still time, in milliseconds
+ */
+ unsigned long tape_still_time_begin;
+ int tape_still_time;
+
+ /*
+ * Speed regulation negative feedback loop
+ */
+ int speed_control;
+ int pipeline_head_speed;
+ int controlled_pipeline_head_speed;
+ int uncontrolled_pipeline_head_speed;
+ int controlled_last_pipeline_head;
+ int uncontrolled_last_pipeline_head;
+ unsigned long uncontrolled_pipeline_head_time;
+ unsigned long controlled_pipeline_head_time;
+ int controlled_previous_pipeline_head;
+ int uncontrolled_previous_pipeline_head;
+ unsigned long controlled_previous_head_time;
+ unsigned long uncontrolled_previous_head_time;
+ int restart_speed_control_req;
+
+ /*
+ * Debug_level determines amount of debugging output;
+ * can be changed using /proc/ide/hdx/settings
+ * 0 : almost no debugging output
+ * 1 : 0+output errors only
+ * 2 : 1+output all sensekey/asc
+ * 3 : 2+follow all chrdev related procedures
+ * 4 : 3+follow all procedures
+ * 5 : 4+include pc_stack rq_stack info
+ * 6 : 5+USE_COUNT updates
+ */
+ int debug_level;
+} idetape_tape_t;
+
+static DECLARE_MUTEX(idetape_ref_sem);
+
+#define to_ide_tape(obj) container_of(obj, struct ide_tape_obj, kref)
+
+#define ide_tape_g(disk) \
+ container_of((disk)->private_data, struct ide_tape_obj, driver)
+
+static struct ide_tape_obj *ide_tape_get(struct gendisk *disk)
+{
+ struct ide_tape_obj *tape = NULL;
+
+ down(&idetape_ref_sem);
+ tape = ide_tape_g(disk);
+ if (tape)
+ kref_get(&tape->kref);
+ up(&idetape_ref_sem);
+ return tape;
+}
+
+static void ide_tape_release(struct kref *);
+
+static void ide_tape_put(struct ide_tape_obj *tape)
+{
+ down(&idetape_ref_sem);
+ kref_put(&tape->kref, ide_tape_release);
+ up(&idetape_ref_sem);
+}
+
+/*
+ * Tape door status
+ */
+#define DOOR_UNLOCKED 0
+#define DOOR_LOCKED 1
+#define DOOR_EXPLICITLY_LOCKED 2
+
+/*
+ * Tape flag bits values.
+ */
+#define IDETAPE_IGNORE_DSC 0
+#define IDETAPE_ADDRESS_VALID 1 /* 0 When the tape position is unknown */
+#define IDETAPE_BUSY 2 /* Device already opened */
+#define IDETAPE_PIPELINE_ERROR 3 /* Error detected in a pipeline stage */
+#define IDETAPE_DETECT_BS 4 /* Attempt to auto-detect the current user block size */
+#define IDETAPE_FILEMARK 5 /* Currently on a filemark */
+#define IDETAPE_DRQ_INTERRUPT 6 /* DRQ interrupt device */
+#define IDETAPE_READ_ERROR 7
+#define IDETAPE_PIPELINE_ACTIVE 8 /* pipeline active */
+/* 0 = no tape is loaded, so we don't rewind after ejecting */
+#define IDETAPE_MEDIUM_PRESENT 9
+
+/*
+ * Supported ATAPI tape drives packet commands
+ */
+#define IDETAPE_TEST_UNIT_READY_CMD 0x00
+#define IDETAPE_REWIND_CMD 0x01
+#define IDETAPE_REQUEST_SENSE_CMD 0x03
+#define IDETAPE_READ_CMD 0x08
+#define IDETAPE_WRITE_CMD 0x0a
+#define IDETAPE_WRITE_FILEMARK_CMD 0x10
+#define IDETAPE_SPACE_CMD 0x11
+#define IDETAPE_INQUIRY_CMD 0x12
+#define IDETAPE_ERASE_CMD 0x19
+#define IDETAPE_MODE_SENSE_CMD 0x1a
+#define IDETAPE_MODE_SELECT_CMD 0x15
+#define IDETAPE_LOAD_UNLOAD_CMD 0x1b
+#define IDETAPE_PREVENT_CMD 0x1e
+#define IDETAPE_LOCATE_CMD 0x2b
+#define IDETAPE_READ_POSITION_CMD 0x34
+#define IDETAPE_READ_BUFFER_CMD 0x3c
+#define IDETAPE_SET_SPEED_CMD 0xbb
+
+/*
+ * Some defines for the READ BUFFER command
+ */
+#define IDETAPE_RETRIEVE_FAULTY_BLOCK 6
+
+/*
+ * Some defines for the SPACE command
+ */
+#define IDETAPE_SPACE_OVER_FILEMARK 1
+#define IDETAPE_SPACE_TO_EOD 3
+
+/*
+ * Some defines for the LOAD UNLOAD command
+ */
+#define IDETAPE_LU_LOAD_MASK 1
+#define IDETAPE_LU_RETENSION_MASK 2
+#define IDETAPE_LU_EOT_MASK 4
+
+/*
+ * Special requests for our block device strategy routine.
+ *
+ * In order to service a character device command, we add special
+ * requests to the tail of our block device request queue and wait
+ * for their completion.
+ */
+
+enum {
+ REQ_IDETAPE_PC1 = (1 << 0), /* packet command (first stage) */
+ REQ_IDETAPE_PC2 = (1 << 1), /* packet command (second stage) */
+ REQ_IDETAPE_READ = (1 << 2),
+ REQ_IDETAPE_WRITE = (1 << 3),
+ REQ_IDETAPE_READ_BUFFER = (1 << 4),
+};
+
+/*
+ * Error codes which are returned in rq->errors to the higher part
+ * of the driver.
+ */
+#define IDETAPE_ERROR_GENERAL 101
+#define IDETAPE_ERROR_FILEMARK 102
+#define IDETAPE_ERROR_EOD 103
+
+/*
+ * The following is used to format the general configuration word of
+ * the ATAPI IDENTIFY DEVICE command.
+ */
+struct idetape_id_gcw {
+ unsigned packet_size :2; /* Packet Size */
+ unsigned reserved234 :3; /* Reserved */
+ unsigned drq_type :2; /* Command packet DRQ type */
+ unsigned removable :1; /* Removable media */
+ unsigned device_type :5; /* Device type */
+ unsigned reserved13 :1; /* Reserved */
+ unsigned protocol :2; /* Protocol type */
+};
+
+/*
+ * INQUIRY packet command - Data Format (From Table 6-8 of QIC-157C)
+ */
+typedef struct {
+ unsigned device_type :5; /* Peripheral Device Type */
+ unsigned reserved0_765 :3; /* Peripheral Qualifier - Reserved */
+ unsigned reserved1_6t0 :7; /* Reserved */
+ unsigned rmb :1; /* Removable Medium Bit */
+ unsigned ansi_version :3; /* ANSI Version */
+ unsigned ecma_version :3; /* ECMA Version */
+ unsigned iso_version :2; /* ISO Version */
+ unsigned response_format :4; /* Response Data Format */
+ unsigned reserved3_45 :2; /* Reserved */
+ unsigned reserved3_6 :1; /* TrmIOP - Reserved */
+ unsigned reserved3_7 :1; /* AENC - Reserved */
+ __u8 additional_length; /* Additional Length (total_length-4) */
+ __u8 rsv5, rsv6, rsv7; /* Reserved */
+ __u8 vendor_id[8]; /* Vendor Identification */
+ __u8 product_id[16]; /* Product Identification */
+ __u8 revision_level[4]; /* Revision Level */
+ __u8 vendor_specific[20]; /* Vendor Specific - Optional */
+ __u8 reserved56t95[40]; /* Reserved - Optional */
+ /* Additional information may be returned */
+} idetape_inquiry_result_t;
+
+/*
+ * READ POSITION packet command - Data Format (From Table 6-57)
+ */
+typedef struct {
+ unsigned reserved0_10 :2; /* Reserved */
+ unsigned bpu :1; /* Block Position Unknown */
+ unsigned reserved0_543 :3; /* Reserved */
+ unsigned eop :1; /* End Of Partition */
+ unsigned bop :1; /* Beginning Of Partition */
+ u8 partition; /* Partition Number */
+ u8 reserved2, reserved3; /* Reserved */
+ u32 first_block; /* First Block Location */
+ u32 last_block; /* Last Block Location (Optional) */
+ u8 reserved12; /* Reserved */
+ u8 blocks_in_buffer[3]; /* Blocks In Buffer - (Optional) */
+ u32 bytes_in_buffer; /* Bytes In Buffer (Optional) */
+} idetape_read_position_result_t;
+
+/*
+ * Follows structures which are related to the SELECT SENSE / MODE SENSE
+ * packet commands. Those packet commands are still not supported
+ * by ide-tape.
+ */
+#define IDETAPE_BLOCK_DESCRIPTOR 0
+#define IDETAPE_CAPABILITIES_PAGE 0x2a
+#define IDETAPE_PARAMTR_PAGE 0x2b /* Onstream DI-x0 only */
+#define IDETAPE_BLOCK_SIZE_PAGE 0x30
+#define IDETAPE_BUFFER_FILLING_PAGE 0x33
+
+/*
+ * Mode Parameter Header for the MODE SENSE packet command
+ */
+typedef struct {
+ __u8 mode_data_length; /* Length of the following data transfer */
+ __u8 medium_type; /* Medium Type */
+ __u8 dsp; /* Device Specific Parameter */
+ __u8 bdl; /* Block Descriptor Length */
+#if 0
+ /* data transfer page */
+ __u8 page_code :6;
+ __u8 reserved0_6 :1;
+ __u8 ps :1; /* parameters saveable */
+ __u8 page_length; /* page Length == 0x02 */
+ __u8 reserved2;
+ __u8 read32k :1; /* 32k blk size (data only) */
+ __u8 read32k5 :1; /* 32.5k blk size (data&AUX) */
+ __u8 reserved3_23 :2;
+ __u8 write32k :1; /* 32k blk size (data only) */
+ __u8 write32k5 :1; /* 32.5k blk size (data&AUX) */
+ __u8 reserved3_6 :1;
+ __u8 streaming :1; /* streaming mode enable */
+#endif
+} idetape_mode_parameter_header_t;
+
+/*
+ * Mode Parameter Block Descriptor the MODE SENSE packet command
+ *
+ * Support for block descriptors is optional.
+ */
+typedef struct {
+ __u8 density_code; /* Medium density code */
+ __u8 blocks[3]; /* Number of blocks */
+ __u8 reserved4; /* Reserved */
+ __u8 length[3]; /* Block Length */
+} idetape_parameter_block_descriptor_t;
+
+/*
+ * The Data Compression Page, as returned by the MODE SENSE packet command.
+ */
+typedef struct {
+ unsigned page_code :6; /* Page Code - Should be 0xf */
+ unsigned reserved0 :1; /* Reserved */
+ unsigned ps :1;
+ __u8 page_length; /* Page Length - Should be 14 */
+ unsigned reserved2 :6; /* Reserved */
+ unsigned dcc :1; /* Data Compression Capable */
+ unsigned dce :1; /* Data Compression Enable */
+ unsigned reserved3 :5; /* Reserved */
+ unsigned red :2; /* Report Exception on Decompression */
+ unsigned dde :1; /* Data Decompression Enable */
+ __u32 ca; /* Compression Algorithm */
+ __u32 da; /* Decompression Algorithm */
+ __u8 reserved[4]; /* Reserved */
+} idetape_data_compression_page_t;
+
+/*
+ * The Medium Partition Page, as returned by the MODE SENSE packet command.
+ */
+typedef struct {
+ unsigned page_code :6; /* Page Code - Should be 0x11 */
+ unsigned reserved1_6 :1; /* Reserved */
+ unsigned ps :1;
+ __u8 page_length; /* Page Length - Should be 6 */
+ __u8 map; /* Maximum Additional Partitions - Should be 0 */
+ __u8 apd; /* Additional Partitions Defined - Should be 0 */
+ unsigned reserved4_012 :3; /* Reserved */
+ unsigned psum :2; /* Should be 0 */
+ unsigned idp :1; /* Should be 0 */
+ unsigned sdp :1; /* Should be 0 */
+ unsigned fdp :1; /* Fixed Data Partitions */
+ __u8 mfr; /* Medium Format Recognition */
+ __u8 reserved[2]; /* Reserved */
+} idetape_medium_partition_page_t;
+
+/*
+ * Run time configurable parameters.
+ */
+typedef struct {
+ int dsc_rw_frequency;
+ int dsc_media_access_frequency;
+ int nr_stages;
+} idetape_config_t;
+
+/*
+ * The variables below are used for the character device interface.
+ * Additional state variables are defined in our ide_drive_t structure.
+ */
+static struct ide_tape_obj * idetape_devs[MAX_HWIFS * MAX_DRIVES];
+
+#define ide_tape_f(file) ((file)->private_data)
+
+static struct ide_tape_obj *ide_tape_chrdev_get(unsigned int i)
+{
+ struct ide_tape_obj *tape = NULL;
+
+ down(&idetape_ref_sem);
+ tape = idetape_devs[i];
+ if (tape)
+ kref_get(&tape->kref);
+ up(&idetape_ref_sem);
+ return tape;
+}
+
+/*
+ * Function declarations
+ *
+ */
+static int idetape_chrdev_release (struct inode *inode, struct file *filp);
+static void idetape_write_release (ide_drive_t *drive, unsigned int minor);
+
+/*
+ * Too bad. The drive wants to send us data which we are not ready to accept.
+ * Just throw it away.
+ */
+static void idetape_discard_data (ide_drive_t *drive, unsigned int bcount)
+{
+ while (bcount--)
+ (void) HWIF(drive)->INB(IDE_DATA_REG);
+}
+
+static void idetape_input_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount)
+{
+ struct idetape_bh *bh = pc->bh;
+ int count;
+
+ while (bcount) {
+#if IDETAPE_DEBUG_BUGS
+ if (bh == NULL) {
+ printk(KERN_ERR "ide-tape: bh == NULL in "
+ "idetape_input_buffers\n");
+ idetape_discard_data(drive, bcount);
+ return;
+ }
+#endif /* IDETAPE_DEBUG_BUGS */
+ count = min((unsigned int)(bh->b_size - atomic_read(&bh->b_count)), bcount);
+ HWIF(drive)->atapi_input_bytes(drive, bh->b_data + atomic_read(&bh->b_count), count);
+ bcount -= count;
+ atomic_add(count, &bh->b_count);
+ if (atomic_read(&bh->b_count) == bh->b_size) {
+ bh = bh->b_reqnext;
+ if (bh)
+ atomic_set(&bh->b_count, 0);
+ }
+ }
+ pc->bh = bh;
+}
+
+static void idetape_output_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount)
+{
+ struct idetape_bh *bh = pc->bh;
+ int count;
+
+ while (bcount) {
+#if IDETAPE_DEBUG_BUGS
+ if (bh == NULL) {
+ printk(KERN_ERR "ide-tape: bh == NULL in "
+ "idetape_output_buffers\n");
+ return;
+ }
+#endif /* IDETAPE_DEBUG_BUGS */
+ count = min((unsigned int)pc->b_count, (unsigned int)bcount);
+ HWIF(drive)->atapi_output_bytes(drive, pc->b_data, count);
+ bcount -= count;
+ pc->b_data += count;
+ pc->b_count -= count;
+ if (!pc->b_count) {
+ pc->bh = bh = bh->b_reqnext;
+ if (bh) {
+ pc->b_data = bh->b_data;
+ pc->b_count = atomic_read(&bh->b_count);
+ }
+ }
+ }
+}
+
+static void idetape_update_buffers (idetape_pc_t *pc)
+{
+ struct idetape_bh *bh = pc->bh;
+ int count;
+ unsigned int bcount = pc->actually_transferred;
+
+ if (test_bit(PC_WRITING, &pc->flags))
+ return;
+ while (bcount) {
+#if IDETAPE_DEBUG_BUGS
+ if (bh == NULL) {
+ printk(KERN_ERR "ide-tape: bh == NULL in "
+ "idetape_update_buffers\n");
+ return;
+ }
+#endif /* IDETAPE_DEBUG_BUGS */
+ count = min((unsigned int)bh->b_size, (unsigned int)bcount);
+ atomic_set(&bh->b_count, count);
+ if (atomic_read(&bh->b_count) == bh->b_size)
+ bh = bh->b_reqnext;
+ bcount -= count;
+ }
+ pc->bh = bh;
+}
+
+/*
+ * idetape_next_pc_storage returns a pointer to a place in which we can
+ * safely store a packet command, even though we intend to leave the
+ * driver. A storage space for a maximum of IDETAPE_PC_STACK packet
+ * commands is allocated at initialization time.
+ */
+static idetape_pc_t *idetape_next_pc_storage (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 5)
+ printk(KERN_INFO "ide-tape: pc_stack_index=%d\n",
+ tape->pc_stack_index);
+#endif /* IDETAPE_DEBUG_LOG */
+ if (tape->pc_stack_index == IDETAPE_PC_STACK)
+ tape->pc_stack_index=0;
+ return (&tape->pc_stack[tape->pc_stack_index++]);
+}
+
+/*
+ * idetape_next_rq_storage is used along with idetape_next_pc_storage.
+ * Since we queue packet commands in the request queue, we need to
+ * allocate a request, along with the allocation of a packet command.
+ */
+
+/**************************************************************
+ * *
+ * This should get fixed to use kmalloc(.., GFP_ATOMIC) *
+ * followed later on by kfree(). -ml *
+ * *
+ **************************************************************/
+
+static struct request *idetape_next_rq_storage (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 5)
+ printk(KERN_INFO "ide-tape: rq_stack_index=%d\n",
+ tape->rq_stack_index);
+#endif /* IDETAPE_DEBUG_LOG */
+ if (tape->rq_stack_index == IDETAPE_PC_STACK)
+ tape->rq_stack_index=0;
+ return (&tape->rq_stack[tape->rq_stack_index++]);
+}
+
+/*
+ * idetape_init_pc initializes a packet command.
+ */
+static void idetape_init_pc (idetape_pc_t *pc)
+{
+ memset(pc->c, 0, 12);
+ pc->retries = 0;
+ pc->flags = 0;
+ pc->request_transfer = 0;
+ pc->buffer = pc->pc_buffer;
+ pc->buffer_size = IDETAPE_PC_BUFFER_SIZE;
+ pc->bh = NULL;
+ pc->b_data = NULL;
+}
+
+/*
+ * idetape_analyze_error is called on each failed packet command retry
+ * to analyze the request sense. We currently do not utilize this
+ * information.
+ */
+static void idetape_analyze_error (ide_drive_t *drive, idetape_request_sense_result_t *result)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ idetape_pc_t *pc = tape->failed_pc;
+
+ tape->sense = *result;
+ tape->sense_key = result->sense_key;
+ tape->asc = result->asc;
+ tape->ascq = result->ascq;
+#if IDETAPE_DEBUG_LOG
+ /*
+ * Without debugging, we only log an error if we decided to
+ * give up retrying.
+ */
+ if (tape->debug_level >= 1)
+ printk(KERN_INFO "ide-tape: pc = %x, sense key = %x, "
+ "asc = %x, ascq = %x\n",
+ pc->c[0], result->sense_key,
+ result->asc, result->ascq);
+#endif /* IDETAPE_DEBUG_LOG */
+
+ /*
+ * Correct pc->actually_transferred by asking the tape.
+ */
+ if (test_bit(PC_DMA_ERROR, &pc->flags)) {
+ pc->actually_transferred = pc->request_transfer - tape->tape_block_size * ntohl(get_unaligned(&result->information));
+ idetape_update_buffers(pc);
+ }
+
+ /*
+ * If error was the result of a zero-length read or write command,
+ * with sense key=5, asc=0x22, ascq=0, let it slide. Some drives
+ * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes.
+ */
+ if ((pc->c[0] == IDETAPE_READ_CMD || pc->c[0] == IDETAPE_WRITE_CMD)
+ && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) { /* length==0 */
+ if (result->sense_key == 5) {
+ /* don't report an error, everything's ok */
+ pc->error = 0;
+ /* don't retry read/write */
+ set_bit(PC_ABORT, &pc->flags);
+ }
+ }
+ if (pc->c[0] == IDETAPE_READ_CMD && result->filemark) {
+ pc->error = IDETAPE_ERROR_FILEMARK;
+ set_bit(PC_ABORT, &pc->flags);
+ }
+ if (pc->c[0] == IDETAPE_WRITE_CMD) {
+ if (result->eom ||
+ (result->sense_key == 0xd && result->asc == 0x0 &&
+ result->ascq == 0x2)) {
+ pc->error = IDETAPE_ERROR_EOD;
+ set_bit(PC_ABORT, &pc->flags);
+ }
+ }
+ if (pc->c[0] == IDETAPE_READ_CMD || pc->c[0] == IDETAPE_WRITE_CMD) {
+ if (result->sense_key == 8) {
+ pc->error = IDETAPE_ERROR_EOD;
+ set_bit(PC_ABORT, &pc->flags);
+ }
+ if (!test_bit(PC_ABORT, &pc->flags) &&
+ pc->actually_transferred)
+ pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
+ }
+}
+
+/*
+ * idetape_active_next_stage will declare the next stage as "active".
+ */
+static void idetape_active_next_stage (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ idetape_stage_t *stage = tape->next_stage;
+ struct request *rq = &stage->rq;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 4)
+ printk(KERN_INFO "ide-tape: Reached idetape_active_next_stage\n");
+#endif /* IDETAPE_DEBUG_LOG */
+#if IDETAPE_DEBUG_BUGS
+ if (stage == NULL) {
+ printk(KERN_ERR "ide-tape: bug: Trying to activate a non existing stage\n");
+ return;
+ }
+#endif /* IDETAPE_DEBUG_BUGS */
+
+ rq->rq_disk = tape->disk;
+ rq->buffer = NULL;
+ rq->special = (void *)stage->bh;
+ tape->active_data_request = rq;
+ tape->active_stage = stage;
+ tape->next_stage = stage->next;
+}
+
+/*
+ * idetape_increase_max_pipeline_stages is a part of the feedback
+ * loop which tries to find the optimum number of stages. In the
+ * feedback loop, we are starting from a minimum maximum number of
+ * stages, and if we sense that the pipeline is empty, we try to
+ * increase it, until we reach the user compile time memory limit.
+ */
+static void idetape_increase_max_pipeline_stages (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ int increase = (tape->max_pipeline - tape->min_pipeline) / 10;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 4)
+ printk (KERN_INFO "ide-tape: Reached idetape_increase_max_pipeline_stages\n");
+#endif /* IDETAPE_DEBUG_LOG */
+
+ tape->max_stages += max(increase, 1);
+ tape->max_stages = max(tape->max_stages, tape->min_pipeline);
+ tape->max_stages = min(tape->max_stages, tape->max_pipeline);
+}
+
+/*
+ * idetape_kfree_stage calls kfree to completely free a stage, along with
+ * its related buffers.
+ */
+static void __idetape_kfree_stage (idetape_stage_t *stage)
+{
+ struct idetape_bh *prev_bh, *bh = stage->bh;
+ int size;
+
+ while (bh != NULL) {
+ if (bh->b_data != NULL) {
+ size = (int) bh->b_size;
+ while (size > 0) {
+ free_page((unsigned long) bh->b_data);
+ size -= PAGE_SIZE;
+ bh->b_data += PAGE_SIZE;
+ }
+ }
+ prev_bh = bh;
+ bh = bh->b_reqnext;
+ kfree(prev_bh);
+ }
+ kfree(stage);
+}
+
+static void idetape_kfree_stage (idetape_tape_t *tape, idetape_stage_t *stage)
+{
+ __idetape_kfree_stage(stage);
+}
+
+/*
+ * idetape_remove_stage_head removes tape->first_stage from the pipeline.
+ * The caller should avoid race conditions.
+ */
+static void idetape_remove_stage_head (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ idetape_stage_t *stage;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 4)
+ printk(KERN_INFO "ide-tape: Reached idetape_remove_stage_head\n");
+#endif /* IDETAPE_DEBUG_LOG */
+#if IDETAPE_DEBUG_BUGS
+ if (tape->first_stage == NULL) {
+ printk(KERN_ERR "ide-tape: bug: tape->first_stage is NULL\n");
+ return;
+ }
+ if (tape->active_stage == tape->first_stage) {
+ printk(KERN_ERR "ide-tape: bug: Trying to free our active pipeline stage\n");
+ return;
+ }
+#endif /* IDETAPE_DEBUG_BUGS */
+ stage = tape->first_stage;
+ tape->first_stage = stage->next;
+ idetape_kfree_stage(tape, stage);
+ tape->nr_stages--;
+ if (tape->first_stage == NULL) {
+ tape->last_stage = NULL;
+#if IDETAPE_DEBUG_BUGS
+ if (tape->next_stage != NULL)
+ printk(KERN_ERR "ide-tape: bug: tape->next_stage != NULL\n");
+ if (tape->nr_stages)
+ printk(KERN_ERR "ide-tape: bug: nr_stages should be 0 now\n");
+#endif /* IDETAPE_DEBUG_BUGS */
+ }
+}
+
+/*
+ * This will free all the pipeline stages starting from new_last_stage->next
+ * to the end of the list, and point tape->last_stage to new_last_stage.
+ */
+static void idetape_abort_pipeline(ide_drive_t *drive,
+ idetape_stage_t *new_last_stage)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ idetape_stage_t *stage = new_last_stage->next;
+ idetape_stage_t *nstage;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 4)
+ printk(KERN_INFO "ide-tape: %s: idetape_abort_pipeline called\n", tape->name);
+#endif
+ while (stage) {
+ nstage = stage->next;
+ idetape_kfree_stage(tape, stage);
+ --tape->nr_stages;
+ --tape->nr_pending_stages;
+ stage = nstage;
+ }
+ if (new_last_stage)
+ new_last_stage->next = NULL;
+ tape->last_stage = new_last_stage;
+ tape->next_stage = NULL;
+}
+
+/*
+ * idetape_end_request is used to finish servicing a request, and to
+ * insert a pending pipeline request into the main device queue.
+ */
+static int idetape_end_request(ide_drive_t *drive, int uptodate, int nr_sects)
+{
+ struct request *rq = HWGROUP(drive)->rq;
+ idetape_tape_t *tape = drive->driver_data;
+ unsigned long flags;
+ int error;
+ int remove_stage = 0;
+ idetape_stage_t *active_stage;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 4)
+ printk(KERN_INFO "ide-tape: Reached idetape_end_request\n");
+#endif /* IDETAPE_DEBUG_LOG */
+
+ switch (uptodate) {
+ case 0: error = IDETAPE_ERROR_GENERAL; break;
+ case 1: error = 0; break;
+ default: error = uptodate;
+ }
+ rq->errors = error;
+ if (error)
+ tape->failed_pc = NULL;
+
+ spin_lock_irqsave(&tape->spinlock, flags);
+
+ /* The request was a pipelined data transfer request */
+ if (tape->active_data_request == rq) {
+ active_stage = tape->active_stage;
+ tape->active_stage = NULL;
+ tape->active_data_request = NULL;
+ tape->nr_pending_stages--;
+ if (rq->cmd[0] & REQ_IDETAPE_WRITE) {
+ remove_stage = 1;
+ if (error) {
+ set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
+ if (error == IDETAPE_ERROR_EOD)
+ idetape_abort_pipeline(drive, active_stage);
+ }
+ } else if (rq->cmd[0] & REQ_IDETAPE_READ) {
+ if (error == IDETAPE_ERROR_EOD) {
+ set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
+ idetape_abort_pipeline(drive, active_stage);
+ }
+ }
+ if (tape->next_stage != NULL) {
+ idetape_active_next_stage(drive);
+
+ /*
+ * Insert the next request into the request queue.
+ */
+ (void) ide_do_drive_cmd(drive, tape->active_data_request, ide_end);
+ } else if (!error) {
+ idetape_increase_max_pipeline_stages(drive);
+ }
+ }
+ ide_end_drive_cmd(drive, 0, 0);
+// blkdev_dequeue_request(rq);
+// drive->rq = NULL;
+// end_that_request_last(rq);
+
+ if (remove_stage)
+ idetape_remove_stage_head(drive);
+ if (tape->active_data_request == NULL)
+ clear_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
+ spin_unlock_irqrestore(&tape->spinlock, flags);
+ return 0;
+}
+
+static ide_startstop_t idetape_request_sense_callback (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 4)
+ printk(KERN_INFO "ide-tape: Reached idetape_request_sense_callback\n");
+#endif /* IDETAPE_DEBUG_LOG */
+ if (!tape->pc->error) {
+ idetape_analyze_error(drive, (idetape_request_sense_result_t *) tape->pc->buffer);
+ idetape_end_request(drive, 1, 0);
+ } else {
+ printk(KERN_ERR "ide-tape: Error in REQUEST SENSE itself - Aborting request!\n");
+ idetape_end_request(drive, 0, 0);
+ }
+ return ide_stopped;
+}
+
+static void idetape_create_request_sense_cmd (idetape_pc_t *pc)
+{
+ idetape_init_pc(pc);
+ pc->c[0] = IDETAPE_REQUEST_SENSE_CMD;
+ pc->c[4] = 20;
+ pc->request_transfer = 20;
+ pc->callback = &idetape_request_sense_callback;
+}
+
+static void idetape_init_rq(struct request *rq, u8 cmd)
+{
+ memset(rq, 0, sizeof(*rq));
+ rq->flags = REQ_SPECIAL;
+ rq->cmd[0] = cmd;
+}
+
+/*
+ * idetape_queue_pc_head generates a new packet command request in front
+ * of the request queue, before the current request, so that it will be
+ * processed immediately, on the next pass through the driver.
+ *
+ * idetape_queue_pc_head is called from the request handling part of
+ * the driver (the "bottom" part). Safe storage for the request should
+ * be allocated with idetape_next_pc_storage and idetape_next_rq_storage
+ * before calling idetape_queue_pc_head.
+ *
+ * Memory for those requests is pre-allocated at initialization time, and
+ * is limited to IDETAPE_PC_STACK requests. We assume that we have enough
+ * space for the maximum possible number of inter-dependent packet commands.
+ *
+ * The higher level of the driver - The ioctl handler and the character
+ * device handling functions should queue request to the lower level part
+ * and wait for their completion using idetape_queue_pc_tail or
+ * idetape_queue_rw_tail.
+ */
+static void idetape_queue_pc_head (ide_drive_t *drive, idetape_pc_t *pc,struct request *rq)
+{
+ struct ide_tape_obj *tape = drive->driver_data;
+
+ idetape_init_rq(rq, REQ_IDETAPE_PC1);
+ rq->buffer = (char *) pc;
+ rq->rq_disk = tape->disk;
+ (void) ide_do_drive_cmd(drive, rq, ide_preempt);
+}
+
+/*
+ * idetape_retry_pc is called when an error was detected during the
+ * last packet command. We queue a request sense packet command in
+ * the head of the request list.
+ */
+static ide_startstop_t idetape_retry_pc (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ idetape_pc_t *pc;
+ struct request *rq;
+ atapi_error_t error;
+
+ error.all = HWIF(drive)->INB(IDE_ERROR_REG);
+ pc = idetape_next_pc_storage(drive);
+ rq = idetape_next_rq_storage(drive);
+ idetape_create_request_sense_cmd(pc);
+ set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
+ idetape_queue_pc_head(drive, pc, rq);
+ return ide_stopped;
+}
+
+/*
+ * idetape_postpone_request postpones the current request so that
+ * ide.c will be able to service requests from another device on
+ * the same hwgroup while we are polling for DSC.
+ */
+static void idetape_postpone_request (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 4)
+ printk(KERN_INFO "ide-tape: idetape_postpone_request\n");
+#endif
+ tape->postponed_rq = HWGROUP(drive)->rq;
+ ide_stall_queue(drive, tape->dsc_polling_frequency);
+}
+
+/*
+ * idetape_pc_intr is the usual interrupt handler which will be called
+ * during a packet command. We will transfer some of the data (as
+ * requested by the drive) and will re-point interrupt handler to us.
+ * When data transfer is finished, we will act according to the
+ * algorithm described before idetape_issue_packet_command.
+ *
+ */
+static ide_startstop_t idetape_pc_intr (ide_drive_t *drive)
+{
+ ide_hwif_t *hwif = drive->hwif;
+ idetape_tape_t *tape = drive->driver_data;
+ atapi_status_t status;
+ atapi_bcount_t bcount;
+ atapi_ireason_t ireason;
+ idetape_pc_t *pc = tape->pc;
+
+ unsigned int temp;
+#if SIMULATE_ERRORS
+ static int error_sim_count = 0;
+#endif
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 4)
+ printk(KERN_INFO "ide-tape: Reached idetape_pc_intr "
+ "interrupt handler\n");
+#endif /* IDETAPE_DEBUG_LOG */
+
+ /* Clear the interrupt */
+ status.all = HWIF(drive)->INB(IDE_STATUS_REG);
+
+ if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags)) {
+ if (HWIF(drive)->ide_dma_end(drive) || status.b.check) {
+ /*
+ * A DMA error is sometimes expected. For example,
+ * if the tape is crossing a filemark during a
+ * READ command, it will issue an irq and position
+ * itself before the filemark, so that only a partial
+ * data transfer will occur (which causes the DMA
+ * error). In that case, we will later ask the tape
+ * how much bytes of the original request were
+ * actually transferred (we can't receive that
+ * information from the DMA engine on most chipsets).
+ */
+
+ /*
+ * On the contrary, a DMA error is never expected;
+ * it usually indicates a hardware error or abort.
+ * If the tape crosses a filemark during a READ
+ * command, it will issue an irq and position itself
+ * after the filemark (not before). Only a partial
+ * data transfer will occur, but no DMA error.
+ * (AS, 19 Apr 2001)
+ */
+ set_bit(PC_DMA_ERROR, &pc->flags);
+ } else {
+ pc->actually_transferred = pc->request_transfer;
+ idetape_update_buffers(pc);
+ }
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 4)
+ printk(KERN_INFO "ide-tape: DMA finished\n");
+#endif /* IDETAPE_DEBUG_LOG */
+ }
+
+ /* No more interrupts */
+ if (!status.b.drq) {
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 2)
+ printk(KERN_INFO "ide-tape: Packet command completed, %d bytes transferred\n", pc->actually_transferred);
+#endif /* IDETAPE_DEBUG_LOG */
+ clear_bit(PC_DMA_IN_PROGRESS, &pc->flags);
+
+ local_irq_enable();
+
+#if SIMULATE_ERRORS
+ if ((pc->c[0] == IDETAPE_WRITE_CMD ||
+ pc->c[0] == IDETAPE_READ_CMD) &&
+ (++error_sim_count % 100) == 0) {
+ printk(KERN_INFO "ide-tape: %s: simulating error\n",
+ tape->name);
+ status.b.check = 1;
+ }
+#endif
+ if (status.b.check && pc->c[0] == IDETAPE_REQUEST_SENSE_CMD)
+ status.b.check = 0;
+ if (status.b.check || test_bit(PC_DMA_ERROR, &pc->flags)) { /* Error detected */
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 1)
+ printk(KERN_INFO "ide-tape: %s: I/O error\n",
+ tape->name);
+#endif /* IDETAPE_DEBUG_LOG */
+ if (pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) {
+ printk(KERN_ERR "ide-tape: I/O error in request sense command\n");
+ return ide_do_reset(drive);
+ }
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 1)
+ printk(KERN_INFO "ide-tape: [cmd %x]: check condition\n", pc->c[0]);
+#endif
+ /* Retry operation */
+ return idetape_retry_pc(drive);
+ }
+ pc->error = 0;
+ if (test_bit(PC_WAIT_FOR_DSC, &pc->flags) &&
+ !status.b.dsc) {
+ /* Media access command */
+ tape->dsc_polling_start = jiffies;
+ tape->dsc_polling_frequency = IDETAPE_DSC_MA_FAST;
+ tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
+ /* Allow ide.c to handle other requests */
+ idetape_postpone_request(drive);
+ return ide_stopped;
+ }
+ if (tape->failed_pc == pc)
+ tape->failed_pc = NULL;
+ /* Command finished - Call the callback function */
+ return pc->callback(drive);
+ }
+ if (test_and_clear_bit(PC_DMA_IN_PROGRESS, &pc->flags)) {
+ printk(KERN_ERR "ide-tape: The tape wants to issue more "
+ "interrupts in DMA mode\n");
+ printk(KERN_ERR "ide-tape: DMA disabled, reverting to PIO\n");
+ (void)__ide_dma_off(drive);
+ return ide_do_reset(drive);
+ }
+ /* Get the number of bytes to transfer on this interrupt. */
+ bcount.b.high = hwif->INB(IDE_BCOUNTH_REG);
+ bcount.b.low = hwif->INB(IDE_BCOUNTL_REG);
+
+ ireason.all = hwif->INB(IDE_IREASON_REG);
+
+ if (ireason.b.cod) {
+ printk(KERN_ERR "ide-tape: CoD != 0 in idetape_pc_intr\n");
+ return ide_do_reset(drive);
+ }
+ if (ireason.b.io == test_bit(PC_WRITING, &pc->flags)) {
+ /* Hopefully, we will never get here */
+ printk(KERN_ERR "ide-tape: We wanted to %s, ",
+ ireason.b.io ? "Write":"Read");
+ printk(KERN_ERR "ide-tape: but the tape wants us to %s !\n",
+ ireason.b.io ? "Read":"Write");
+ return ide_do_reset(drive);
+ }
+ if (!test_bit(PC_WRITING, &pc->flags)) {
+ /* Reading - Check that we have enough space */
+ temp = pc->actually_transferred + bcount.all;
+ if (temp > pc->request_transfer) {
+ if (temp > pc->buffer_size) {
+ printk(KERN_ERR "ide-tape: The tape wants to send us more data than expected - discarding data\n");
+ idetape_discard_data(drive, bcount.all);
+ ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
+ return ide_started;
+ }
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 2)
+ printk(KERN_NOTICE "ide-tape: The tape wants to send us more data than expected - allowing transfer\n");
+#endif /* IDETAPE_DEBUG_LOG */
+ }
+ }
+ if (test_bit(PC_WRITING, &pc->flags)) {
+ if (pc->bh != NULL)
+ idetape_output_buffers(drive, pc, bcount.all);
+ else
+ /* Write the current buffer */
+ HWIF(drive)->atapi_output_bytes(drive, pc->current_position, bcount.all);
+ } else {
+ if (pc->bh != NULL)
+ idetape_input_buffers(drive, pc, bcount.all);
+ else
+ /* Read the current buffer */
+ HWIF(drive)->atapi_input_bytes(drive, pc->current_position, bcount.all);
+ }
+ /* Update the current position */
+ pc->actually_transferred += bcount.all;
+ pc->current_position += bcount.all;
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 2)
+ printk(KERN_INFO "ide-tape: [cmd %x] transferred %d bytes on that interrupt\n", pc->c[0], bcount.all);
+#endif
+ /* And set the interrupt handler again */
+ ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
+ return ide_started;
+}
+
+/*
+ * Packet Command Interface
+ *
+ * The current Packet Command is available in tape->pc, and will not
+ * change until we finish handling it. Each packet command is associated
+ * with a callback function that will be called when the command is
+ * finished.
+ *
+ * The handling will be done in three stages:
+ *
+ * 1. idetape_issue_packet_command will send the packet command to the
+ * drive, and will set the interrupt handler to idetape_pc_intr.
+ *
+ * 2. On each interrupt, idetape_pc_intr will be called. This step
+ * will be repeated until the device signals us that no more
+ * interrupts will be issued.
+ *
+ * 3. ATAPI Tape media access commands have immediate status with a
+ * delayed process. In case of a successful initiation of a
+ * media access packet command, the DSC bit will be set when the
+ * actual execution of the command is finished.
+ * Since the tape drive will not issue an interrupt, we have to
+ * poll for this event. In this case, we define the request as
+ * "low priority request" by setting rq_status to
+ * IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and exit
+ * the driver.
+ *
+ * ide.c will then give higher priority to requests which
+ * originate from the other device, until will change rq_status
+ * to RQ_ACTIVE.
+ *
+ * 4. When the packet command is finished, it will be checked for errors.
+ *
+ * 5. In case an error was found, we queue a request sense packet
+ * command in front of the request queue and retry the operation
+ * up to IDETAPE_MAX_PC_RETRIES times.
+ *
+ * 6. In case no error was found, or we decided to give up and not
+ * to retry again, the callback function will be called and then
+ * we will handle the next request.
+ *
+ */
+static ide_startstop_t idetape_transfer_pc(ide_drive_t *drive)
+{
+ ide_hwif_t *hwif = drive->hwif;
+ idetape_tape_t *tape = drive->driver_data;
+ idetape_pc_t *pc = tape->pc;
+ atapi_ireason_t ireason;
+ int retries = 100;
+ ide_startstop_t startstop;
+
+ if (ide_wait_stat(&startstop,drive,DRQ_STAT,BUSY_STAT,WAIT_READY)) {
+ printk(KERN_ERR "ide-tape: Strange, packet command initiated yet DRQ isn't asserted\n");
+ return startstop;
+ }
+ ireason.all = hwif->INB(IDE_IREASON_REG);
+ while (retries-- && (!ireason.b.cod || ireason.b.io)) {
+ printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while issuing "
+ "a packet command, retrying\n");
+ udelay(100);
+ ireason.all = hwif->INB(IDE_IREASON_REG);
+ if (retries == 0) {
+ printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while "
+ "issuing a packet command, ignoring\n");
+ ireason.b.cod = 1;
+ ireason.b.io = 0;
+ }
+ }
+ if (!ireason.b.cod || ireason.b.io) {
+ printk(KERN_ERR "ide-tape: (IO,CoD) != (0,1) while issuing "
+ "a packet command\n");
+ return ide_do_reset(drive);
+ }
+ /* Set the interrupt routine */
+ ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
+#ifdef CONFIG_BLK_DEV_IDEDMA
+ /* Begin DMA, if necessary */
+ if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags))
+ hwif->dma_start(drive);
+#endif
+ /* Send the actual packet */
+ HWIF(drive)->atapi_output_bytes(drive, pc->c, 12);
+ return ide_started;
+}
+
+static ide_startstop_t idetape_issue_packet_command (ide_drive_t *drive, idetape_pc_t *pc)
+{
+ ide_hwif_t *hwif = drive->hwif;
+ idetape_tape_t *tape = drive->driver_data;
+ atapi_bcount_t bcount;
+ int dma_ok = 0;
+
+#if IDETAPE_DEBUG_BUGS
+ if (tape->pc->c[0] == IDETAPE_REQUEST_SENSE_CMD &&
+ pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) {
+ printk(KERN_ERR "ide-tape: possible ide-tape.c bug - "
+ "Two request sense in serial were issued\n");
+ }
+#endif /* IDETAPE_DEBUG_BUGS */
+
+ if (tape->failed_pc == NULL && pc->c[0] != IDETAPE_REQUEST_SENSE_CMD)
+ tape->failed_pc = pc;
+ /* Set the current packet command */
+ tape->pc = pc;
+
+ if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
+ test_bit(PC_ABORT, &pc->flags)) {
+ /*
+ * We will "abort" retrying a packet command in case
+ * a legitimate error code was received (crossing a
+ * filemark, or end of the media, for example).
+ */
+ if (!test_bit(PC_ABORT, &pc->flags)) {
+ if (!(pc->c[0] == IDETAPE_TEST_UNIT_READY_CMD &&
+ tape->sense_key == 2 && tape->asc == 4 &&
+ (tape->ascq == 1 || tape->ascq == 8))) {
+ printk(KERN_ERR "ide-tape: %s: I/O error, "
+ "pc = %2x, key = %2x, "
+ "asc = %2x, ascq = %2x\n",
+ tape->name, pc->c[0],
+ tape->sense_key, tape->asc,
+ tape->ascq);
+ }
+ /* Giving up */
+ pc->error = IDETAPE_ERROR_GENERAL;
+ }
+ tape->failed_pc = NULL;
+ return pc->callback(drive);
+ }
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 2)
+ printk(KERN_INFO "ide-tape: Retry number - %d, cmd = %02X\n", pc->retries, pc->c[0]);
+#endif /* IDETAPE_DEBUG_LOG */
+
+ pc->retries++;
+ /* We haven't transferred any data yet */
+ pc->actually_transferred = 0;
+ pc->current_position = pc->buffer;
+ /* Request to transfer the entire buffer at once */
+ bcount.all = pc->request_transfer;
+
+ if (test_and_clear_bit(PC_DMA_ERROR, &pc->flags)) {
+ printk(KERN_WARNING "ide-tape: DMA disabled, "
+ "reverting to PIO\n");
+ (void)__ide_dma_off(drive);
+ }
+ if (test_bit(PC_DMA_RECOMMENDED, &pc->flags) && drive->using_dma)
+ dma_ok = !hwif->dma_setup(drive);
+
+ if (IDE_CONTROL_REG)
+ hwif->OUTB(drive->ctl, IDE_CONTROL_REG);
+ hwif->OUTB(dma_ok ? 1 : 0, IDE_FEATURE_REG); /* Use PIO/DMA */
+ hwif->OUTB(bcount.b.high, IDE_BCOUNTH_REG);
+ hwif->OUTB(bcount.b.low, IDE_BCOUNTL_REG);
+ hwif->OUTB(drive->select.all, IDE_SELECT_REG);
+ if (dma_ok) /* Will begin DMA later */
+ set_bit(PC_DMA_IN_PROGRESS, &pc->flags);
+ if (test_bit(IDETAPE_DRQ_INTERRUPT, &tape->flags)) {
+ ide_set_handler(drive, &idetape_transfer_pc, IDETAPE_WAIT_CMD, NULL);
+ hwif->OUTB(WIN_PACKETCMD, IDE_COMMAND_REG);
+ return ide_started;
+ } else {
+ hwif->OUTB(WIN_PACKETCMD, IDE_COMMAND_REG);
+ return idetape_transfer_pc(drive);
+ }
+}
+
+/*
+ * General packet command callback function.
+ */
+static ide_startstop_t idetape_pc_callback (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 4)
+ printk(KERN_INFO "ide-tape: Reached idetape_pc_callback\n");
+#endif /* IDETAPE_DEBUG_LOG */
+
+ idetape_end_request(drive, tape->pc->error ? 0 : 1, 0);
+ return ide_stopped;
+}
+
+/*
+ * A mode sense command is used to "sense" tape parameters.
+ */
+static void idetape_create_mode_sense_cmd (idetape_pc_t *pc, u8 page_code)
+{
+ idetape_init_pc(pc);
+ pc->c[0] = IDETAPE_MODE_SENSE_CMD;
+ if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
+ pc->c[1] = 8; /* DBD = 1 - Don't return block descriptors */
+ pc->c[2] = page_code;
+ /*
+ * Changed pc->c[3] to 0 (255 will at best return unused info).
+ *
+ * For SCSI this byte is defined as subpage instead of high byte
+ * of length and some IDE drives seem to interpret it this way
+ * and return an error when 255 is used.
+ */
+ pc->c[3] = 0;
+ pc->c[4] = 255; /* (We will just discard data in that case) */
+ if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
+ pc->request_transfer = 12;
+ else if (page_code == IDETAPE_CAPABILITIES_PAGE)
+ pc->request_transfer = 24;
+ else
+ pc->request_transfer = 50;
+ pc->callback = &idetape_pc_callback;
+}
+
+static void calculate_speeds(ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ int full = 125, empty = 75;
+
+ if (time_after(jiffies, tape->controlled_pipeline_head_time + 120 * HZ)) {
+ tape->controlled_previous_pipeline_head = tape->controlled_last_pipeline_head;
+ tape->controlled_previous_head_time = tape->controlled_pipeline_head_time;
+ tape->controlled_last_pipeline_head = tape->pipeline_head;
+ tape->controlled_pipeline_head_time = jiffies;
+ }
+ if (time_after(jiffies, tape->controlled_pipeline_head_time + 60 * HZ))
+ tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_last_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_pipeline_head_time);
+ else if (time_after(jiffies, tape->controlled_previous_head_time))
+ tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_previous_head_time);
+
+ if (tape->nr_pending_stages < tape->max_stages /*- 1 */) {
+ /* -1 for read mode error recovery */
+ if (time_after(jiffies, tape->uncontrolled_previous_head_time + 10 * HZ)) {
+ tape->uncontrolled_pipeline_head_time = jiffies;
+ tape->uncontrolled_pipeline_head_speed = (tape->pipeline_head - tape->uncontrolled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->uncontrolled_previous_head_time);
+ }
+ } else {
+ tape->uncontrolled_previous_head_time = jiffies;
+ tape->uncontrolled_previous_pipeline_head = tape->pipeline_head;
+ if (time_after(jiffies, tape->uncontrolled_pipeline_head_time + 30 * HZ)) {
+ tape->uncontrolled_pipeline_head_time = jiffies;
+ }
+ }
+ tape->pipeline_head_speed = max(tape->uncontrolled_pipeline_head_speed, tape->controlled_pipeline_head_speed);
+ if (tape->speed_control == 0) {
+ tape->max_insert_speed = 5000;
+ } else if (tape->speed_control == 1) {
+ if (tape->nr_pending_stages >= tape->max_stages / 2)
+ tape->max_insert_speed = tape->pipeline_head_speed +
+ (1100 - tape->pipeline_head_speed) * 2 * (tape->nr_pending_stages - tape->max_stages / 2) / tape->max_stages;
+ else
+ tape->max_insert_speed = 500 +
+ (tape->pipeline_head_speed - 500) * 2 * tape->nr_pending_stages / tape->max_stages;
+ if (tape->nr_pending_stages >= tape->max_stages * 99 / 100)
+ tape->max_insert_speed = 5000;
+ } else if (tape->speed_control == 2) {
+ tape->max_insert_speed = tape->pipeline_head_speed * empty / 100 +
+ (tape->pipeline_head_speed * full / 100 - tape->pipeline_head_speed * empty / 100) * tape->nr_pending_stages / tape->max_stages;
+ } else
+ tape->max_insert_speed = tape->speed_control;
+ tape->max_insert_speed = max(tape->max_insert_speed, 500);
+}
+
+static ide_startstop_t idetape_media_access_finished (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ idetape_pc_t *pc = tape->pc;
+ atapi_status_t status;
+
+ status.all = HWIF(drive)->INB(IDE_STATUS_REG);
+ if (status.b.dsc) {
+ if (status.b.check) {
+ /* Error detected */
+ if (pc->c[0] != IDETAPE_TEST_UNIT_READY_CMD)
+ printk(KERN_ERR "ide-tape: %s: I/O error, ",
+ tape->name);
+ /* Retry operation */
+ return idetape_retry_pc(drive);
+ }
+ pc->error = 0;
+ if (tape->failed_pc == pc)
+ tape->failed_pc = NULL;
+ } else {
+ pc->error = IDETAPE_ERROR_GENERAL;
+ tape->failed_pc = NULL;
+ }
+ return pc->callback(drive);
+}
+
+static ide_startstop_t idetape_rw_callback (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ struct request *rq = HWGROUP(drive)->rq;
+ int blocks = tape->pc->actually_transferred / tape->tape_block_size;
+
+ tape->avg_size += blocks * tape->tape_block_size;
+ tape->insert_size += blocks * tape->tape_block_size;
+ if (tape->insert_size > 1024 * 1024)
+ tape->measure_insert_time = 1;
+ if (tape->measure_insert_time) {
+ tape->measure_insert_time = 0;
+ tape->insert_time = jiffies;
+ tape->insert_size = 0;
+ }
+ if (time_after(jiffies, tape->insert_time))
+ tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time);
+ if (jiffies - tape->avg_time >= HZ) {
+ tape->avg_speed = tape->avg_size * HZ / (jiffies - tape->avg_time) / 1024;
+ tape->avg_size = 0;
+ tape->avg_time = jiffies;
+ }
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 4)
+ printk(KERN_INFO "ide-tape: Reached idetape_rw_callback\n");
+#endif /* IDETAPE_DEBUG_LOG */
+
+ tape->first_frame_position += blocks;
+ rq->current_nr_sectors -= blocks;
+
+ if (!tape->pc->error)
+ idetape_end_request(drive, 1, 0);
+ else
+ idetape_end_request(drive, tape->pc->error, 0);
+ return ide_stopped;
+}
+
+static void idetape_create_read_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
+{
+ idetape_init_pc(pc);
+ pc->c[0] = IDETAPE_READ_CMD;
+ put_unaligned(htonl(length), (unsigned int *) &pc->c[1]);
+ pc->c[1] = 1;
+ pc->callback = &idetape_rw_callback;
+ pc->bh = bh;
+ atomic_set(&bh->b_count, 0);
+ pc->buffer = NULL;
+ pc->request_transfer = pc->buffer_size = length * tape->tape_block_size;
+ if (pc->request_transfer == tape->stage_size)
+ set_bit(PC_DMA_RECOMMENDED, &pc->flags);
+}
+
+static void idetape_create_read_buffer_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
+{
+ int size = 32768;
+ struct idetape_bh *p = bh;
+
+ idetape_init_pc(pc);
+ pc->c[0] = IDETAPE_READ_BUFFER_CMD;
+ pc->c[1] = IDETAPE_RETRIEVE_FAULTY_BLOCK;
+ pc->c[7] = size >> 8;
+ pc->c[8] = size & 0xff;
+ pc->callback = &idetape_pc_callback;
+ pc->bh = bh;
+ atomic_set(&bh->b_count, 0);
+ pc->buffer = NULL;
+ while (p) {
+ atomic_set(&p->b_count, 0);
+ p = p->b_reqnext;
+ }
+ pc->request_transfer = pc->buffer_size = size;
+}
+
+static void idetape_create_write_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
+{
+ idetape_init_pc(pc);
+ pc->c[0] = IDETAPE_WRITE_CMD;
+ put_unaligned(htonl(length), (unsigned int *) &pc->c[1]);
+ pc->c[1] = 1;
+ pc->callback = &idetape_rw_callback;
+ set_bit(PC_WRITING, &pc->flags);
+ pc->bh = bh;
+ pc->b_data = bh->b_data;
+ pc->b_count = atomic_read(&bh->b_count);
+ pc->buffer = NULL;
+ pc->request_transfer = pc->buffer_size = length * tape->tape_block_size;
+ if (pc->request_transfer == tape->stage_size)
+ set_bit(PC_DMA_RECOMMENDED, &pc->flags);
+}
+
+/*
+ * idetape_do_request is our request handling function.
+ */
+static ide_startstop_t idetape_do_request(ide_drive_t *drive,
+ struct request *rq, sector_t block)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ idetape_pc_t *pc = NULL;
+ struct request *postponed_rq = tape->postponed_rq;
+ atapi_status_t status;
+
+#if IDETAPE_DEBUG_LOG
+#if 0
+ if (tape->debug_level >= 5)
+ printk(KERN_INFO "ide-tape: rq_status: %d, "
+ "dev: %s, cmd: %ld, errors: %d\n", rq->rq_status,
+ rq->rq_disk->disk_name, rq->cmd[0], rq->errors);
+#endif
+ if (tape->debug_level >= 2)
+ printk(KERN_INFO "ide-tape: sector: %ld, "
+ "nr_sectors: %ld, current_nr_sectors: %d\n",
+ rq->sector, rq->nr_sectors, rq->current_nr_sectors);
+#endif /* IDETAPE_DEBUG_LOG */
+
+ if ((rq->flags & REQ_SPECIAL) == 0) {
+ /*
+ * We do not support buffer cache originated requests.
+ */
+ printk(KERN_NOTICE "ide-tape: %s: Unsupported request in "
+ "request queue (%ld)\n", drive->name, rq->flags);
+ ide_end_request(drive, 0, 0);
+ return ide_stopped;
+ }
+
+ /*
+ * Retry a failed packet command
+ */
+ if (tape->failed_pc != NULL &&
+ tape->pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) {
+ return idetape_issue_packet_command(drive, tape->failed_pc);
+ }
+#if IDETAPE_DEBUG_BUGS
+ if (postponed_rq != NULL)
+ if (rq != postponed_rq) {
+ printk(KERN_ERR "ide-tape: ide-tape.c bug - "
+ "Two DSC requests were queued\n");
+ idetape_end_request(drive, 0, 0);
+ return ide_stopped;
+ }
+#endif /* IDETAPE_DEBUG_BUGS */
+
+ tape->postponed_rq = NULL;
+
+ /*
+ * If the tape is still busy, postpone our request and service
+ * the other device meanwhile.
+ */
+ status.all = HWIF(drive)->INB(IDE_STATUS_REG);
+
+ if (!drive->dsc_overlap && !(rq->cmd[0] & REQ_IDETAPE_PC2))
+ set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
+
+ if (drive->post_reset == 1) {
+ set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
+ drive->post_reset = 0;
+ }
+
+ if (tape->tape_still_time > 100 && tape->tape_still_time < 200)
+ tape->measure_insert_time = 1;
+ if (time_after(jiffies, tape->insert_time))
+ tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time);
+ calculate_speeds(drive);
+ if (!test_and_clear_bit(IDETAPE_IGNORE_DSC, &tape->flags) &&
+ !status.b.dsc) {
+ if (postponed_rq == NULL) {
+ tape->dsc_polling_start = jiffies;
+ tape->dsc_polling_frequency = tape->best_dsc_rw_frequency;
+ tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
+ } else if (time_after(jiffies, tape->dsc_timeout)) {
+ printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
+ tape->name);
+ if (rq->cmd[0] & REQ_IDETAPE_PC2) {
+ idetape_media_access_finished(drive);
+ return ide_stopped;
+ } else {
+ return ide_do_reset(drive);
+ }
+ } else if (jiffies - tape->dsc_polling_start > IDETAPE_DSC_MA_THRESHOLD)
+ tape->dsc_polling_frequency = IDETAPE_DSC_MA_SLOW;
+ idetape_postpone_request(drive);
+ return ide_stopped;
+ }
+ if (rq->cmd[0] & REQ_IDETAPE_READ) {
+ tape->buffer_head++;
+#if USE_IOTRACE
+ IO_trace(IO_IDETAPE_FIFO, tape->pipeline_head, tape->buffer_head, tape->tape_head, tape->minor);
+#endif
+ tape->postpone_cnt = 0;
+ pc = idetape_next_pc_storage(drive);
+ idetape_create_read_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
+ goto out;
+ }
+ if (rq->cmd[0] & REQ_IDETAPE_WRITE) {
+ tape->buffer_head++;
+#if USE_IOTRACE
+ IO_trace(IO_IDETAPE_FIFO, tape->pipeline_head, tape->buffer_head, tape->tape_head, tape->minor);
+#endif
+ tape->postpone_cnt = 0;
+ pc = idetape_next_pc_storage(drive);
+ idetape_create_write_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
+ goto out;
+ }
+ if (rq->cmd[0] & REQ_IDETAPE_READ_BUFFER) {
+ tape->postpone_cnt = 0;
+ pc = idetape_next_pc_storage(drive);
+ idetape_create_read_buffer_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
+ goto out;
+ }
+ if (rq->cmd[0] & REQ_IDETAPE_PC1) {
+ pc = (idetape_pc_t *) rq->buffer;
+ rq->cmd[0] &= ~(REQ_IDETAPE_PC1);
+ rq->cmd[0] |= REQ_IDETAPE_PC2;
+ goto out;
+ }
+ if (rq->cmd[0] & REQ_IDETAPE_PC2) {
+ idetape_media_access_finished(drive);
+ return ide_stopped;
+ }
+ BUG();
+out:
+ return idetape_issue_packet_command(drive, pc);
+}
+
+/*
+ * Pipeline related functions
+ */
+static inline int idetape_pipeline_active (idetape_tape_t *tape)
+{
+ int rc1, rc2;
+
+ rc1 = test_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
+ rc2 = (tape->active_data_request != NULL);
+ return rc1;
+}
+
+/*
+ * idetape_kmalloc_stage uses __get_free_page to allocate a pipeline
+ * stage, along with all the necessary small buffers which together make
+ * a buffer of size tape->stage_size (or a bit more). We attempt to
+ * combine sequential pages as much as possible.
+ *
+ * Returns a pointer to the new allocated stage, or NULL if we
+ * can't (or don't want to) allocate a stage.
+ *
+ * Pipeline stages are optional and are used to increase performance.
+ * If we can't allocate them, we'll manage without them.
+ */
+static idetape_stage_t *__idetape_kmalloc_stage (idetape_tape_t *tape, int full, int clear)
+{
+ idetape_stage_t *stage;
+ struct idetape_bh *prev_bh, *bh;
+ int pages = tape->pages_per_stage;
+ char *b_data = NULL;
+
+ if ((stage = (idetape_stage_t *) kmalloc (sizeof (idetape_stage_t),GFP_KERNEL)) == NULL)
+ return NULL;
+ stage->next = NULL;
+
+ bh = stage->bh = (struct idetape_bh *)kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);
+ if (bh == NULL)
+ goto abort;
+ bh->b_reqnext = NULL;
+ if ((bh->b_data = (char *) __get_free_page (GFP_KERNEL)) == NULL)
+ goto abort;
+ if (clear)
+ memset(bh->b_data, 0, PAGE_SIZE);
+ bh->b_size = PAGE_SIZE;
+ atomic_set(&bh->b_count, full ? bh->b_size : 0);
+
+ while (--pages) {
+ if ((b_data = (char *) __get_free_page (GFP_KERNEL)) == NULL)
+ goto abort;
+ if (clear)
+ memset(b_data, 0, PAGE_SIZE);
+ if (bh->b_data == b_data + PAGE_SIZE) {
+ bh->b_size += PAGE_SIZE;
+ bh->b_data -= PAGE_SIZE;
+ if (full)
+ atomic_add(PAGE_SIZE, &bh->b_count);
+ continue;
+ }
+ if (b_data == bh->b_data + bh->b_size) {
+ bh->b_size += PAGE_SIZE;
+ if (full)
+ atomic_add(PAGE_SIZE, &bh->b_count);
+ continue;
+ }
+ prev_bh = bh;
+ if ((bh = (struct idetape_bh *)kmalloc(sizeof(struct idetape_bh), GFP_KERNEL)) == NULL) {
+ free_page((unsigned long) b_data);
+ goto abort;
+ }
+ bh->b_reqnext = NULL;
+ bh->b_data = b_data;
+ bh->b_size = PAGE_SIZE;
+ atomic_set(&bh->b_count, full ? bh->b_size : 0);
+ prev_bh->b_reqnext = bh;
+ }
+ bh->b_size -= tape->excess_bh_size;
+ if (full)
+ atomic_sub(tape->excess_bh_size, &bh->b_count);
+ return stage;
+abort:
+ __idetape_kfree_stage(stage);
+ return NULL;
+}
+
+static idetape_stage_t *idetape_kmalloc_stage (idetape_tape_t *tape)
+{
+ idetape_stage_t *cache_stage = tape->cache_stage;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 4)
+ printk(KERN_INFO "ide-tape: Reached idetape_kmalloc_stage\n");
+#endif /* IDETAPE_DEBUG_LOG */
+
+ if (tape->nr_stages >= tape->max_stages)
+ return NULL;
+ if (cache_stage != NULL) {
+ tape->cache_stage = NULL;
+ return cache_stage;
+ }
+ return __idetape_kmalloc_stage(tape, 0, 0);
+}
+
+static void idetape_copy_stage_from_user (idetape_tape_t *tape, idetape_stage_t *stage, const char __user *buf, int n)
+{
+ struct idetape_bh *bh = tape->bh;
+ int count;
+
+ while (n) {
+#if IDETAPE_DEBUG_BUGS
+ if (bh == NULL) {
+ printk(KERN_ERR "ide-tape: bh == NULL in "
+ "idetape_copy_stage_from_user\n");
+ return;
+ }
+#endif /* IDETAPE_DEBUG_BUGS */
+ count = min((unsigned int)(bh->b_size - atomic_read(&bh->b_count)), (unsigned int)n);
+ copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf, count);
+ n -= count;
+ atomic_add(count, &bh->b_count);
+ buf += count;
+ if (atomic_read(&bh->b_count) == bh->b_size) {
+ bh = bh->b_reqnext;
+ if (bh)
+ atomic_set(&bh->b_count, 0);
+ }
+ }
+ tape->bh = bh;
+}
+
+static void idetape_copy_stage_to_user (idetape_tape_t *tape, char __user *buf, idetape_stage_t *stage, int n)
+{
+ struct idetape_bh *bh = tape->bh;
+ int count;
+
+ while (n) {
+#if IDETAPE_DEBUG_BUGS
+ if (bh == NULL) {
+ printk(KERN_ERR "ide-tape: bh == NULL in "
+ "idetape_copy_stage_to_user\n");
+ return;
+ }
+#endif /* IDETAPE_DEBUG_BUGS */
+ count = min(tape->b_count, n);
+ copy_to_user(buf, tape->b_data, count);
+ n -= count;
+ tape->b_data += count;
+ tape->b_count -= count;
+ buf += count;
+ if (!tape->b_count) {
+ tape->bh = bh = bh->b_reqnext;
+ if (bh) {
+ tape->b_data = bh->b_data;
+ tape->b_count = atomic_read(&bh->b_count);
+ }
+ }
+ }
+}
+
+static void idetape_init_merge_stage (idetape_tape_t *tape)
+{
+ struct idetape_bh *bh = tape->merge_stage->bh;
+
+ tape->bh = bh;
+ if (tape->chrdev_direction == idetape_direction_write)
+ atomic_set(&bh->b_count, 0);
+ else {
+ tape->b_data = bh->b_data;
+ tape->b_count = atomic_read(&bh->b_count);
+ }
+}
+
+static void idetape_switch_buffers (idetape_tape_t *tape, idetape_stage_t *stage)
+{
+ struct idetape_bh *tmp;
+
+ tmp = stage->bh;
+ stage->bh = tape->merge_stage->bh;
+ tape->merge_stage->bh = tmp;
+ idetape_init_merge_stage(tape);
+}
+
+/*
+ * idetape_add_stage_tail adds a new stage at the end of the pipeline.
+ */
+static void idetape_add_stage_tail (ide_drive_t *drive,idetape_stage_t *stage)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ unsigned long flags;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 4)
+ printk (KERN_INFO "ide-tape: Reached idetape_add_stage_tail\n");
+#endif /* IDETAPE_DEBUG_LOG */
+ spin_lock_irqsave(&tape->spinlock, flags);
+ stage->next = NULL;
+ if (tape->last_stage != NULL)
+ tape->last_stage->next=stage;
+ else
+ tape->first_stage = tape->next_stage=stage;
+ tape->last_stage = stage;
+ if (tape->next_stage == NULL)
+ tape->next_stage = tape->last_stage;
+ tape->nr_stages++;
+ tape->nr_pending_stages++;
+ spin_unlock_irqrestore(&tape->spinlock, flags);
+}
+
+/*
+ * idetape_wait_for_request installs a completion in a pending request
+ * and sleeps until it is serviced.
+ *
+ * The caller should ensure that the request will not be serviced
+ * before we install the completion (usually by disabling interrupts).
+ */
+static void idetape_wait_for_request (ide_drive_t *drive, struct request *rq)
+{
+ DECLARE_COMPLETION(wait);
+ idetape_tape_t *tape = drive->driver_data;
+
+#if IDETAPE_DEBUG_BUGS
+ if (rq == NULL || (rq->flags & REQ_SPECIAL) == 0) {
+ printk (KERN_ERR "ide-tape: bug: Trying to sleep on non-valid request\n");
+ return;
+ }
+#endif /* IDETAPE_DEBUG_BUGS */
+ rq->waiting = &wait;
+ rq->end_io = blk_end_sync_rq;
+ spin_unlock_irq(&tape->spinlock);
+ wait_for_completion(&wait);
+ /* The stage and its struct request have been deallocated */
+ spin_lock_irq(&tape->spinlock);
+}
+
+static ide_startstop_t idetape_read_position_callback (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ idetape_read_position_result_t *result;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 4)
+ printk(KERN_INFO "ide-tape: Reached idetape_read_position_callback\n");
+#endif /* IDETAPE_DEBUG_LOG */
+
+ if (!tape->pc->error) {
+ result = (idetape_read_position_result_t *) tape->pc->buffer;
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 2)
+ printk(KERN_INFO "ide-tape: BOP - %s\n",result->bop ? "Yes":"No");
+ if (tape->debug_level >= 2)
+ printk(KERN_INFO "ide-tape: EOP - %s\n",result->eop ? "Yes":"No");
+#endif /* IDETAPE_DEBUG_LOG */
+ if (result->bpu) {
+ printk(KERN_INFO "ide-tape: Block location is unknown to the tape\n");
+ clear_bit(IDETAPE_ADDRESS_VALID, &tape->flags);
+ idetape_end_request(drive, 0, 0);
+ } else {
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 2)
+ printk(KERN_INFO "ide-tape: Block Location - %u\n", ntohl(result->first_block));
+#endif /* IDETAPE_DEBUG_LOG */
+ tape->partition = result->partition;
+ tape->first_frame_position = ntohl(result->first_block);
+ tape->last_frame_position = ntohl(result->last_block);
+ tape->blocks_in_buffer = result->blocks_in_buffer[2];
+ set_bit(IDETAPE_ADDRESS_VALID, &tape->flags);
+ idetape_end_request(drive, 1, 0);
+ }
+ } else {
+ idetape_end_request(drive, 0, 0);
+ }
+ return ide_stopped;
+}
+
+/*
+ * idetape_create_write_filemark_cmd will:
+ *
+ * 1. Write a filemark if write_filemark=1.
+ * 2. Flush the device buffers without writing a filemark
+ * if write_filemark=0.
+ *
+ */
+static void idetape_create_write_filemark_cmd (ide_drive_t *drive, idetape_pc_t *pc,int write_filemark)
+{
+ idetape_init_pc(pc);
+ pc->c[0] = IDETAPE_WRITE_FILEMARK_CMD;
+ pc->c[4] = write_filemark;
+ set_bit(PC_WAIT_FOR_DSC, &pc->flags);
+ pc->callback = &idetape_pc_callback;
+}
+
+static void idetape_create_test_unit_ready_cmd(idetape_pc_t *pc)
+{
+ idetape_init_pc(pc);
+ pc->c[0] = IDETAPE_TEST_UNIT_READY_CMD;
+ pc->callback = &idetape_pc_callback;
+}
+
+/*
+ * idetape_queue_pc_tail is based on the following functions:
+ *
+ * ide_do_drive_cmd from ide.c
+ * cdrom_queue_request and cdrom_queue_packet_command from ide-cd.c
+ *
+ * We add a special packet command request to the tail of the request
+ * queue, and wait for it to be serviced.
+ *
+ * This is not to be called from within the request handling part
+ * of the driver ! We allocate here data in the stack, and it is valid
+ * until the request is finished. This is not the case for the bottom
+ * part of the driver, where we are always leaving the functions to wait
+ * for an interrupt or a timer event.
+ *
+ * From the bottom part of the driver, we should allocate safe memory
+ * using idetape_next_pc_storage and idetape_next_rq_storage, and add
+ * the request to the request list without waiting for it to be serviced !
+ * In that case, we usually use idetape_queue_pc_head.
+ */
+static int __idetape_queue_pc_tail (ide_drive_t *drive, idetape_pc_t *pc)
+{
+ struct ide_tape_obj *tape = drive->driver_data;
+ struct request rq;
+
+ idetape_init_rq(&rq, REQ_IDETAPE_PC1);
+ rq.buffer = (char *) pc;
+ rq.rq_disk = tape->disk;
+ return ide_do_drive_cmd(drive, &rq, ide_wait);
+}
+
+static void idetape_create_load_unload_cmd (ide_drive_t *drive, idetape_pc_t *pc,int cmd)
+{
+ idetape_init_pc(pc);
+ pc->c[0] = IDETAPE_LOAD_UNLOAD_CMD;
+ pc->c[4] = cmd;
+ set_bit(PC_WAIT_FOR_DSC, &pc->flags);
+ pc->callback = &idetape_pc_callback;
+}
+
+static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ idetape_pc_t pc;
+ int load_attempted = 0;
+
+ /*
+ * Wait for the tape to become ready
+ */
+ set_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags);
+ timeout += jiffies;
+ while (time_before(jiffies, timeout)) {
+ idetape_create_test_unit_ready_cmd(&pc);
+ if (!__idetape_queue_pc_tail(drive, &pc))
+ return 0;
+ if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
+ || (tape->asc == 0x3A)) { /* no media */
+ if (load_attempted)
+ return -ENOMEDIUM;
+ idetape_create_load_unload_cmd(drive, &pc, IDETAPE_LU_LOAD_MASK);
+ __idetape_queue_pc_tail(drive, &pc);
+ load_attempted = 1;
+ /* not about to be ready */
+ } else if (!(tape->sense_key == 2 && tape->asc == 4 &&
+ (tape->ascq == 1 || tape->ascq == 8)))
+ return -EIO;
+ current->state = TASK_INTERRUPTIBLE;
+ schedule_timeout(HZ / 10);
+ }
+ return -EIO;
+}
+
+static int idetape_queue_pc_tail (ide_drive_t *drive,idetape_pc_t *pc)
+{
+ return __idetape_queue_pc_tail(drive, pc);
+}
+
+static int idetape_flush_tape_buffers (ide_drive_t *drive)
+{
+ idetape_pc_t pc;
+ int rc;
+
+ idetape_create_write_filemark_cmd(drive, &pc, 0);
+ if ((rc = idetape_queue_pc_tail(drive, &pc)))
+ return rc;
+ idetape_wait_ready(drive, 60 * 5 * HZ);
+ return 0;
+}
+
+static void idetape_create_read_position_cmd (idetape_pc_t *pc)
+{
+ idetape_init_pc(pc);
+ pc->c[0] = IDETAPE_READ_POSITION_CMD;
+ pc->request_transfer = 20;
+ pc->callback = &idetape_read_position_callback;
+}
+
+static int idetape_read_position (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ idetape_pc_t pc;
+ int position;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 4)
+ printk(KERN_INFO "ide-tape: Reached idetape_read_position\n");
+#endif /* IDETAPE_DEBUG_LOG */
+
+ idetape_create_read_position_cmd(&pc);
+ if (idetape_queue_pc_tail(drive, &pc))
+ return -1;
+ position = tape->first_frame_position;
+ return position;
+}
+
+static void idetape_create_locate_cmd (ide_drive_t *drive, idetape_pc_t *pc, unsigned int block, u8 partition, int skip)
+{
+ idetape_init_pc(pc);
+ pc->c[0] = IDETAPE_LOCATE_CMD;
+ pc->c[1] = 2;
+ put_unaligned(htonl(block), (unsigned int *) &pc->c[3]);
+ pc->c[8] = partition;
+ set_bit(PC_WAIT_FOR_DSC, &pc->flags);
+ pc->callback = &idetape_pc_callback;
+}
+
+static int idetape_create_prevent_cmd (ide_drive_t *drive, idetape_pc_t *pc, int prevent)
+{
+ idetape_tape_t *tape = drive->driver_data;
+
+ if (!tape->capabilities.lock)
+ return 0;
+
+ idetape_init_pc(pc);
+ pc->c[0] = IDETAPE_PREVENT_CMD;
+ pc->c[4] = prevent;
+ pc->callback = &idetape_pc_callback;
+ return 1;
+}
+
+static int __idetape_discard_read_pipeline (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ unsigned long flags;
+ int cnt;
+
+ if (tape->chrdev_direction != idetape_direction_read)
+ return 0;
+
+ /* Remove merge stage. */
+ cnt = tape->merge_stage_size / tape->tape_block_size;
+ if (test_and_clear_bit(IDETAPE_FILEMARK, &tape->flags))
+ ++cnt; /* Filemarks count as 1 sector */
+ tape->merge_stage_size = 0;
+ if (tape->merge_stage != NULL) {
+ __idetape_kfree_stage(tape->merge_stage);
+ tape->merge_stage = NULL;
+ }
+
+ /* Clear pipeline flags. */
+ clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
+ tape->chrdev_direction = idetape_direction_none;
+
+ /* Remove pipeline stages. */
+ if (tape->first_stage == NULL)
+ return 0;
+
+ spin_lock_irqsave(&tape->spinlock, flags);
+ tape->next_stage = NULL;
+ if (idetape_pipeline_active(tape))
+ idetape_wait_for_request(drive, tape->active_data_request);
+ spin_unlock_irqrestore(&tape->spinlock, flags);
+
+ while (tape->first_stage != NULL) {
+ struct request *rq_ptr = &tape->first_stage->rq;
+
+ cnt += rq_ptr->nr_sectors - rq_ptr->current_nr_sectors;
+ if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK)
+ ++cnt;
+ idetape_remove_stage_head(drive);
+ }
+ tape->nr_pending_stages = 0;
+ tape->max_stages = tape->min_pipeline;
+ return cnt;
+}
+
+/*
+ * idetape_position_tape positions the tape to the requested block
+ * using the LOCATE packet command. A READ POSITION command is then
+ * issued to check where we are positioned.
+ *
+ * Like all higher level operations, we queue the commands at the tail
+ * of the request queue and wait for their completion.
+ *
+ */
+static int idetape_position_tape (ide_drive_t *drive, unsigned int block, u8 partition, int skip)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ int retval;
+ idetape_pc_t pc;
+
+ if (tape->chrdev_direction == idetape_direction_read)
+ __idetape_discard_read_pipeline(drive);
+ idetape_wait_ready(drive, 60 * 5 * HZ);
+ idetape_create_locate_cmd(drive, &pc, block, partition, skip);
+ retval = idetape_queue_pc_tail(drive, &pc);
+ if (retval)
+ return (retval);
+
+ idetape_create_read_position_cmd(&pc);
+ return (idetape_queue_pc_tail(drive, &pc));
+}
+
+static void idetape_discard_read_pipeline (ide_drive_t *drive, int restore_position)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ int cnt;
+ int seek, position;
+
+ cnt = __idetape_discard_read_pipeline(drive);
+ if (restore_position) {
+ position = idetape_read_position(drive);
+ seek = position > cnt ? position - cnt : 0;
+ if (idetape_position_tape(drive, seek, 0, 0)) {
+ printk(KERN_INFO "ide-tape: %s: position_tape failed in discard_pipeline()\n", tape->name);
+ return;
+ }
+ }
+}
+
+/*
+ * idetape_queue_rw_tail generates a read/write request for the block
+ * device interface and wait for it to be serviced.
+ */
+static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int blocks, struct idetape_bh *bh)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ struct request rq;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 2)
+ printk(KERN_INFO "ide-tape: idetape_queue_rw_tail: cmd=%d\n",cmd);
+#endif /* IDETAPE_DEBUG_LOG */
+#if IDETAPE_DEBUG_BUGS
+ if (idetape_pipeline_active(tape)) {
+ printk(KERN_ERR "ide-tape: bug: the pipeline is active in idetape_queue_rw_tail\n");
+ return (0);
+ }
+#endif /* IDETAPE_DEBUG_BUGS */
+
+ idetape_init_rq(&rq, cmd);
+ rq.rq_disk = tape->disk;
+ rq.special = (void *)bh;
+ rq.sector = tape->first_frame_position;
+ rq.nr_sectors = rq.current_nr_sectors = blocks;
+ (void) ide_do_drive_cmd(drive, &rq, ide_wait);
+
+ if ((cmd & (REQ_IDETAPE_READ | REQ_IDETAPE_WRITE)) == 0)
+ return 0;
+
+ if (tape->merge_stage)
+ idetape_init_merge_stage(tape);
+ if (rq.errors == IDETAPE_ERROR_GENERAL)
+ return -EIO;
+ return (tape->tape_block_size * (blocks-rq.current_nr_sectors));
+}
+
+/*
+ * idetape_insert_pipeline_into_queue is used to start servicing the
+ * pipeline stages, starting from tape->next_stage.
+ */
+static void idetape_insert_pipeline_into_queue (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+
+ if (tape->next_stage == NULL)
+ return;
+ if (!idetape_pipeline_active(tape)) {
+ set_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
+ idetape_active_next_stage(drive);
+ (void) ide_do_drive_cmd(drive, tape->active_data_request, ide_end);
+ }
+}
+
+static void idetape_create_inquiry_cmd (idetape_pc_t *pc)
+{
+ idetape_init_pc(pc);
+ pc->c[0] = IDETAPE_INQUIRY_CMD;
+ pc->c[4] = pc->request_transfer = 254;
+ pc->callback = &idetape_pc_callback;
+}
+
+static void idetape_create_rewind_cmd (ide_drive_t *drive, idetape_pc_t *pc)
+{
+ idetape_init_pc(pc);
+ pc->c[0] = IDETAPE_REWIND_CMD;
+ set_bit(PC_WAIT_FOR_DSC, &pc->flags);
+ pc->callback = &idetape_pc_callback;
+}
+
+#if 0
+static void idetape_create_mode_select_cmd (idetape_pc_t *pc, int length)
+{
+ idetape_init_pc(pc);
+ set_bit(PC_WRITING, &pc->flags);
+ pc->c[0] = IDETAPE_MODE_SELECT_CMD;
+ pc->c[1] = 0x10;
+ put_unaligned(htons(length), (unsigned short *) &pc->c[3]);
+ pc->request_transfer = 255;
+ pc->callback = &idetape_pc_callback;
+}
+#endif
+
+static void idetape_create_erase_cmd (idetape_pc_t *pc)
+{
+ idetape_init_pc(pc);
+ pc->c[0] = IDETAPE_ERASE_CMD;
+ pc->c[1] = 1;
+ set_bit(PC_WAIT_FOR_DSC, &pc->flags);
+ pc->callback = &idetape_pc_callback;
+}
+
+static void idetape_create_space_cmd (idetape_pc_t *pc,int count, u8 cmd)
+{
+ idetape_init_pc(pc);
+ pc->c[0] = IDETAPE_SPACE_CMD;
+ put_unaligned(htonl(count), (unsigned int *) &pc->c[1]);
+ pc->c[1] = cmd;
+ set_bit(PC_WAIT_FOR_DSC, &pc->flags);
+ pc->callback = &idetape_pc_callback;
+}
+
+static void idetape_wait_first_stage (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ unsigned long flags;
+
+ if (tape->first_stage == NULL)
+ return;
+ spin_lock_irqsave(&tape->spinlock, flags);
+ if (tape->active_stage == tape->first_stage)
+ idetape_wait_for_request(drive, tape->active_data_request);
+ spin_unlock_irqrestore(&tape->spinlock, flags);
+}
+
+/*
+ * idetape_add_chrdev_write_request tries to add a character device
+ * originated write request to our pipeline. In case we don't succeed,
+ * we revert to non-pipelined operation mode for this request.
+ *
+ * 1. Try to allocate a new pipeline stage.
+ * 2. If we can't, wait for more and more requests to be serviced
+ * and try again each time.
+ * 3. If we still can't allocate a stage, fallback to
+ * non-pipelined operation mode for this request.
+ */
+static int idetape_add_chrdev_write_request (ide_drive_t *drive, int blocks)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ idetape_stage_t *new_stage;
+ unsigned long flags;
+ struct request *rq;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 3)
+ printk(KERN_INFO "ide-tape: Reached idetape_add_chrdev_write_request\n");
+#endif /* IDETAPE_DEBUG_LOG */
+
+ /*
+ * Attempt to allocate a new stage.
+ * Pay special attention to possible race conditions.
+ */
+ while ((new_stage = idetape_kmalloc_stage(tape)) == NULL) {
+ spin_lock_irqsave(&tape->spinlock, flags);
+ if (idetape_pipeline_active(tape)) {
+ idetape_wait_for_request(drive, tape->active_data_request);
+ spin_unlock_irqrestore(&tape->spinlock, flags);
+ } else {
+ spin_unlock_irqrestore(&tape->spinlock, flags);
+ idetape_insert_pipeline_into_queue(drive);
+ if (idetape_pipeline_active(tape))
+ continue;
+ /*
+ * Linux is short on memory. Fallback to
+ * non-pipelined operation mode for this request.
+ */
+ return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks, tape->merge_stage->bh);
+ }
+ }
+ rq = &new_stage->rq;
+ idetape_init_rq(rq, REQ_IDETAPE_WRITE);
+ /* Doesn't actually matter - We always assume sequential access */
+ rq->sector = tape->first_frame_position;
+ rq->nr_sectors = rq->current_nr_sectors = blocks;
+
+ idetape_switch_buffers(tape, new_stage);
+ idetape_add_stage_tail(drive, new_stage);
+ tape->pipeline_head++;
+#if USE_IOTRACE
+ IO_trace(IO_IDETAPE_FIFO, tape->pipeline_head, tape->buffer_head, tape->tape_head, tape->minor);
+#endif
+ calculate_speeds(drive);
+
+ /*
+ * Estimate whether the tape has stopped writing by checking
+ * if our write pipeline is currently empty. If we are not
+ * writing anymore, wait for the pipeline to be full enough
+ * (90%) before starting to service requests, so that we will
+ * be able to keep up with the higher speeds of the tape.
+ */
+ if (!idetape_pipeline_active(tape)) {
+ if (tape->nr_stages >= tape->max_stages * 9 / 10 ||
+ tape->nr_stages >= tape->max_stages - tape->uncontrolled_pipeline_head_speed * 3 * 1024 / tape->tape_block_size) {
+ tape->measure_insert_time = 1;
+ tape->insert_time = jiffies;
+ tape->insert_size = 0;
+ tape->insert_speed = 0;
+ idetape_insert_pipeline_into_queue(drive);
+ }
+ }
+ if (test_and_clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags))
+ /* Return a deferred error */
+ return -EIO;
+ return blocks;
+}
+
+/*
+ * idetape_wait_for_pipeline will wait until all pending pipeline
+ * requests are serviced. Typically called on device close.
+ */
+static void idetape_wait_for_pipeline (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ unsigned long flags;
+
+ while (tape->next_stage || idetape_pipeline_active(tape)) {
+ idetape_insert_pipeline_into_queue(drive);
+ spin_lock_irqsave(&tape->spinlock, flags);
+ if (idetape_pipeline_active(tape))
+ idetape_wait_for_request(drive, tape->active_data_request);
+ spin_unlock_irqrestore(&tape->spinlock, flags);
+ }
+}
+
+static void idetape_empty_write_pipeline (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ int blocks, min;
+ struct idetape_bh *bh;
+
+#if IDETAPE_DEBUG_BUGS
+ if (tape->chrdev_direction != idetape_direction_write) {
+ printk(KERN_ERR "ide-tape: bug: Trying to empty write pipeline, but we are not writing.\n");
+ return;
+ }
+ if (tape->merge_stage_size > tape->stage_size) {
+ printk(KERN_ERR "ide-tape: bug: merge_buffer too big\n");
+ tape->merge_stage_size = tape->stage_size;
+ }
+#endif /* IDETAPE_DEBUG_BUGS */
+ if (tape->merge_stage_size) {
+ blocks = tape->merge_stage_size / tape->tape_block_size;
+ if (tape->merge_stage_size % tape->tape_block_size) {
+ unsigned int i;
+
+ blocks++;
+ i = tape->tape_block_size - tape->merge_stage_size % tape->tape_block_size;
+ bh = tape->bh->b_reqnext;
+ while (bh) {
+ atomic_set(&bh->b_count, 0);
+ bh = bh->b_reqnext;
+ }
+ bh = tape->bh;
+ while (i) {
+ if (bh == NULL) {
+
+ printk(KERN_INFO "ide-tape: bug, bh NULL\n");
+ break;
+ }
+ min = min(i, (unsigned int)(bh->b_size - atomic_read(&bh->b_count)));
+ memset(bh->b_data + atomic_read(&bh->b_count), 0, min);
+ atomic_add(min, &bh->b_count);
+ i -= min;
+ bh = bh->b_reqnext;
+ }
+ }
+ (void) idetape_add_chrdev_write_request(drive, blocks);
+ tape->merge_stage_size = 0;
+ }
+ idetape_wait_for_pipeline(drive);
+ if (tape->merge_stage != NULL) {
+ __idetape_kfree_stage(tape->merge_stage);
+ tape->merge_stage = NULL;
+ }
+ clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
+ tape->chrdev_direction = idetape_direction_none;
+
+ /*
+ * On the next backup, perform the feedback loop again.
+ * (I don't want to keep sense information between backups,
+ * as some systems are constantly on, and the system load
+ * can be totally different on the next backup).
+ */
+ tape->max_stages = tape->min_pipeline;
+#if IDETAPE_DEBUG_BUGS
+ if (tape->first_stage != NULL ||
+ tape->next_stage != NULL ||
+ tape->last_stage != NULL ||
+ tape->nr_stages != 0) {
+ printk(KERN_ERR "ide-tape: ide-tape pipeline bug, "
+ "first_stage %p, next_stage %p, "
+ "last_stage %p, nr_stages %d\n",
+ tape->first_stage, tape->next_stage,
+ tape->last_stage, tape->nr_stages);
+ }
+#endif /* IDETAPE_DEBUG_BUGS */
+}
+
+static void idetape_restart_speed_control (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+
+ tape->restart_speed_control_req = 0;
+ tape->pipeline_head = 0;
+ tape->controlled_last_pipeline_head = tape->uncontrolled_last_pipeline_head = 0;
+ tape->controlled_previous_pipeline_head = tape->uncontrolled_previous_pipeline_head = 0;
+ tape->pipeline_head_speed = tape->controlled_pipeline_head_speed = 5000;
+ tape->uncontrolled_pipeline_head_speed = 0;
+ tape->controlled_pipeline_head_time = tape->uncontrolled_pipeline_head_time = jiffies;
+ tape->controlled_previous_head_time = tape->uncontrolled_previous_head_time = jiffies;
+}
+
+static int idetape_initiate_read (ide_drive_t *drive, int max_stages)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ idetape_stage_t *new_stage;
+ struct request rq;
+ int bytes_read;
+ int blocks = tape->capabilities.ctl;
+
+ /* Initialize read operation */
+ if (tape->chrdev_direction != idetape_direction_read) {
+ if (tape->chrdev_direction == idetape_direction_write) {
+ idetape_empty_write_pipeline(drive);
+ idetape_flush_tape_buffers(drive);
+ }
+#if IDETAPE_DEBUG_BUGS
+ if (tape->merge_stage || tape->merge_stage_size) {
+ printk (KERN_ERR "ide-tape: merge_stage_size should be 0 now\n");
+ tape->merge_stage_size = 0;
+ }
+#endif /* IDETAPE_DEBUG_BUGS */
+ if ((tape->merge_stage = __idetape_kmalloc_stage(tape, 0, 0)) == NULL)
+ return -ENOMEM;
+ tape->chrdev_direction = idetape_direction_read;
+
+ /*
+ * Issue a read 0 command to ensure that DSC handshake
+ * is switched from completion mode to buffer available
+ * mode.
+ * No point in issuing this if DSC overlap isn't supported,
+ * some drives (Seagate STT3401A) will return an error.
+ */
+ if (drive->dsc_overlap) {
+ bytes_read = idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, 0, tape->merge_stage->bh);
+ if (bytes_read < 0) {
+ __idetape_kfree_stage(tape->merge_stage);
+ tape->merge_stage = NULL;
+ tape->chrdev_direction = idetape_direction_none;
+ return bytes_read;
+ }
+ }
+ }
+ if (tape->restart_speed_control_req)
+ idetape_restart_speed_control(drive);
+ idetape_init_rq(&rq, REQ_IDETAPE_READ);
+ rq.sector = tape->first_frame_position;
+ rq.nr_sectors = rq.current_nr_sectors = blocks;
+ if (!test_bit(IDETAPE_PIPELINE_ERROR, &tape->flags) &&
+ tape->nr_stages < max_stages) {
+ new_stage = idetape_kmalloc_stage(tape);
+ while (new_stage != NULL) {
+ new_stage->rq = rq;
+ idetape_add_stage_tail(drive, new_stage);
+ if (tape->nr_stages >= max_stages)
+ break;
+ new_stage = idetape_kmalloc_stage(tape);
+ }
+ }
+ if (!idetape_pipeline_active(tape)) {
+ if (tape->nr_pending_stages >= 3 * max_stages / 4) {
+ tape->measure_insert_time = 1;
+ tape->insert_time = jiffies;
+ tape->insert_size = 0;
+ tape->insert_speed = 0;
+ idetape_insert_pipeline_into_queue(drive);
+ }
+ }
+ return 0;
+}
+
+/*
+ * idetape_add_chrdev_read_request is called from idetape_chrdev_read
+ * to service a character device read request and add read-ahead
+ * requests to our pipeline.
+ */
+static int idetape_add_chrdev_read_request (ide_drive_t *drive,int blocks)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ unsigned long flags;
+ struct request *rq_ptr;
+ int bytes_read;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 4)
+ printk(KERN_INFO "ide-tape: Reached idetape_add_chrdev_read_request, %d blocks\n", blocks);
+#endif /* IDETAPE_DEBUG_LOG */
+
+ /*
+ * If we are at a filemark, return a read length of 0
+ */
+ if (test_bit(IDETAPE_FILEMARK, &tape->flags))
+ return 0;
+
+ /*
+ * Wait for the next block to be available at the head
+ * of the pipeline
+ */
+ idetape_initiate_read(drive, tape->max_stages);
+ if (tape->first_stage == NULL) {
+ if (test_bit(IDETAPE_PIPELINE_ERROR, &tape->flags))
+ return 0;
+ return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks, tape->merge_stage->bh);
+ }
+ idetape_wait_first_stage(drive);
+ rq_ptr = &tape->first_stage->rq;
+ bytes_read = tape->tape_block_size * (rq_ptr->nr_sectors - rq_ptr->current_nr_sectors);
+ rq_ptr->nr_sectors = rq_ptr->current_nr_sectors = 0;
+
+
+ if (rq_ptr->errors == IDETAPE_ERROR_EOD)
+ return 0;
+ else {
+ idetape_switch_buffers(tape, tape->first_stage);
+ if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK)
+ set_bit(IDETAPE_FILEMARK, &tape->flags);
+ spin_lock_irqsave(&tape->spinlock, flags);
+ idetape_remove_stage_head(drive);
+ spin_unlock_irqrestore(&tape->spinlock, flags);
+ tape->pipeline_head++;
+#if USE_IOTRACE
+ IO_trace(IO_IDETAPE_FIFO, tape->pipeline_head, tape->buffer_head, tape->tape_head, tape->minor);
+#endif
+ calculate_speeds(drive);
+ }
+#if IDETAPE_DEBUG_BUGS
+ if (bytes_read > blocks * tape->tape_block_size) {
+ printk(KERN_ERR "ide-tape: bug: trying to return more bytes than requested\n");
+ bytes_read = blocks * tape->tape_block_size;
+ }
+#endif /* IDETAPE_DEBUG_BUGS */
+ return (bytes_read);
+}
+
+static void idetape_pad_zeros (ide_drive_t *drive, int bcount)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ struct idetape_bh *bh;
+ int blocks;
+
+ while (bcount) {
+ unsigned int count;
+
+ bh = tape->merge_stage->bh;
+ count = min(tape->stage_size, bcount);
+ bcount -= count;
+ blocks = count / tape->tape_block_size;
+ while (count) {
+ atomic_set(&bh->b_count, min(count, (unsigned int)bh->b_size));
+ memset(bh->b_data, 0, atomic_read(&bh->b_count));
+ count -= atomic_read(&bh->b_count);
+ bh = bh->b_reqnext;
+ }
+ idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks, tape->merge_stage->bh);
+ }
+}
+
+static int idetape_pipeline_size (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ idetape_stage_t *stage;
+ struct request *rq;
+ int size = 0;
+
+ idetape_wait_for_pipeline(drive);
+ stage = tape->first_stage;
+ while (stage != NULL) {
+ rq = &stage->rq;
+ size += tape->tape_block_size * (rq->nr_sectors-rq->current_nr_sectors);
+ if (rq->errors == IDETAPE_ERROR_FILEMARK)
+ size += tape->tape_block_size;
+ stage = stage->next;
+ }
+ size += tape->merge_stage_size;
+ return size;
+}
+
+/*
+ * Rewinds the tape to the Beginning Of the current Partition (BOP).
+ *
+ * We currently support only one partition.
+ */
+static int idetape_rewind_tape (ide_drive_t *drive)
+{
+ int retval;
+ idetape_pc_t pc;
+#if IDETAPE_DEBUG_LOG
+ idetape_tape_t *tape = drive->driver_data;
+ if (tape->debug_level >= 2)
+ printk(KERN_INFO "ide-tape: Reached idetape_rewind_tape\n");
+#endif /* IDETAPE_DEBUG_LOG */
+
+ idetape_create_rewind_cmd(drive, &pc);
+ retval = idetape_queue_pc_tail(drive, &pc);
+ if (retval)
+ return retval;
+
+ idetape_create_read_position_cmd(&pc);
+ retval = idetape_queue_pc_tail(drive, &pc);
+ if (retval)
+ return retval;
+ return 0;
+}
+
+/*
+ * Our special ide-tape ioctl's.
+ *
+ * Currently there aren't any ioctl's.
+ * mtio.h compatible commands should be issued to the character device
+ * interface.
+ */
+static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd, unsigned long arg)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ idetape_config_t config;
+ void __user *argp = (void __user *)arg;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 4)
+ printk(KERN_INFO "ide-tape: Reached idetape_blkdev_ioctl\n");
+#endif /* IDETAPE_DEBUG_LOG */
+ switch (cmd) {
+ case 0x0340:
+ if (copy_from_user(&config, argp, sizeof (idetape_config_t)))
+ return -EFAULT;
+ tape->best_dsc_rw_frequency = config.dsc_rw_frequency;
+ tape->max_stages = config.nr_stages;
+ break;
+ case 0x0350:
+ config.dsc_rw_frequency = (int) tape->best_dsc_rw_frequency;
+ config.nr_stages = tape->max_stages;
+ if (copy_to_user(argp, &config, sizeof (idetape_config_t)))
+ return -EFAULT;
+ break;
+ default:
+ return -EIO;
+ }
+ return 0;
+}
+
+/*
+ * idetape_space_over_filemarks is now a bit more complicated than just
+ * passing the command to the tape since we may have crossed some
+ * filemarks during our pipelined read-ahead mode.
+ *
+ * As a minor side effect, the pipeline enables us to support MTFSFM when
+ * the filemark is in our internal pipeline even if the tape doesn't
+ * support spacing over filemarks in the reverse direction.
+ */
+static int idetape_space_over_filemarks (ide_drive_t *drive,short mt_op,int mt_count)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ idetape_pc_t pc;
+ unsigned long flags;
+ int retval,count=0;
+
+ if (mt_count == 0)
+ return 0;
+ if (MTBSF == mt_op || MTBSFM == mt_op) {
+ if (!tape->capabilities.sprev)
+ return -EIO;
+ mt_count = - mt_count;
+ }
+
+ if (tape->chrdev_direction == idetape_direction_read) {
+ /*
+ * We have a read-ahead buffer. Scan it for crossed
+ * filemarks.
+ */
+ tape->merge_stage_size = 0;
+ if (test_and_clear_bit(IDETAPE_FILEMARK, &tape->flags))
+ ++count;
+ while (tape->first_stage != NULL) {
+ if (count == mt_count) {
+ if (mt_op == MTFSFM)
+ set_bit(IDETAPE_FILEMARK, &tape->flags);
+ return 0;
+ }
+ spin_lock_irqsave(&tape->spinlock, flags);
+ if (tape->first_stage == tape->active_stage) {
+ /*
+ * We have reached the active stage in the read pipeline.
+ * There is no point in allowing the drive to continue
+ * reading any farther, so we stop the pipeline.
+ *
+ * This section should be moved to a separate subroutine,
+ * because a similar function is performed in
+ * __idetape_discard_read_pipeline(), for example.
+ */
+ tape->next_stage = NULL;
+ spin_unlock_irqrestore(&tape->spinlock, flags);
+ idetape_wait_first_stage(drive);
+ tape->next_stage = tape->first_stage->next;
+ } else
+ spin_unlock_irqrestore(&tape->spinlock, flags);
+ if (tape->first_stage->rq.errors == IDETAPE_ERROR_FILEMARK)
+ ++count;
+ idetape_remove_stage_head(drive);
+ }
+ idetape_discard_read_pipeline(drive, 0);
+ }
+
+ /*
+ * The filemark was not found in our internal pipeline.
+ * Now we can issue the space command.
+ */
+ switch (mt_op) {
+ case MTFSF:
+ case MTBSF:
+ idetape_create_space_cmd(&pc,mt_count-count,IDETAPE_SPACE_OVER_FILEMARK);
+ return (idetape_queue_pc_tail(drive, &pc));
+ case MTFSFM:
+ case MTBSFM:
+ if (!tape->capabilities.sprev)
+ return (-EIO);
+ retval = idetape_space_over_filemarks(drive, MTFSF, mt_count-count);
+ if (retval) return (retval);
+ count = (MTBSFM == mt_op ? 1 : -1);
+ return (idetape_space_over_filemarks(drive, MTFSF, count));
+ default:
+ printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",mt_op);
+ return (-EIO);
+ }
+}
+
+
+/*
+ * Our character device read / write functions.
+ *
+ * The tape is optimized to maximize throughput when it is transferring
+ * an integral number of the "continuous transfer limit", which is
+ * a parameter of the specific tape (26 KB on my particular tape).
+ * (32 kB for Onstream)
+ *
+ * As of version 1.3 of the driver, the character device provides an
+ * abstract continuous view of the media - any mix of block sizes (even 1
+ * byte) on the same backup/restore procedure is supported. The driver
+ * will internally convert the requests to the recommended transfer unit,
+ * so that an unmatch between the user's block size to the recommended
+ * size will only result in a (slightly) increased driver overhead, but
+ * will no longer hit performance.
+ * This is not applicable to Onstream.
+ */
+static ssize_t idetape_chrdev_read (struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct ide_tape_obj *tape = ide_tape_f(file);
+ ide_drive_t *drive = tape->drive;
+ ssize_t bytes_read,temp, actually_read = 0, rc;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 3)
+ printk(KERN_INFO "ide-tape: Reached idetape_chrdev_read, count %Zd\n", count);
+#endif /* IDETAPE_DEBUG_LOG */
+
+ if (tape->chrdev_direction != idetape_direction_read) {
+ if (test_bit(IDETAPE_DETECT_BS, &tape->flags))
+ if (count > tape->tape_block_size &&
+ (count % tape->tape_block_size) == 0)
+ tape->user_bs_factor = count / tape->tape_block_size;
+ }
+ if ((rc = idetape_initiate_read(drive, tape->max_stages)) < 0)
+ return rc;
+ if (count == 0)
+ return (0);
+ if (tape->merge_stage_size) {
+ actually_read = min((unsigned int)(tape->merge_stage_size), (unsigned int)count);
+ idetape_copy_stage_to_user(tape, buf, tape->merge_stage, actually_read);
+ buf += actually_read;
+ tape->merge_stage_size -= actually_read;
+ count -= actually_read;
+ }
+ while (count >= tape->stage_size) {
+ bytes_read = idetape_add_chrdev_read_request(drive, tape->capabilities.ctl);
+ if (bytes_read <= 0)
+ goto finish;
+ idetape_copy_stage_to_user(tape, buf, tape->merge_stage, bytes_read);
+ buf += bytes_read;
+ count -= bytes_read;
+ actually_read += bytes_read;
+ }
+ if (count) {
+ bytes_read = idetape_add_chrdev_read_request(drive, tape->capabilities.ctl);
+ if (bytes_read <= 0)
+ goto finish;
+ temp = min((unsigned long)count, (unsigned long)bytes_read);
+ idetape_copy_stage_to_user(tape, buf, tape->merge_stage, temp);
+ actually_read += temp;
+ tape->merge_stage_size = bytes_read-temp;
+ }
+finish:
+ if (!actually_read && test_bit(IDETAPE_FILEMARK, &tape->flags)) {
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 2)
+ printk(KERN_INFO "ide-tape: %s: spacing over filemark\n", tape->name);
+#endif
+ idetape_space_over_filemarks(drive, MTFSF, 1);
+ return 0;
+ }
+ return actually_read;
+}
+
+static ssize_t idetape_chrdev_write (struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct ide_tape_obj *tape = ide_tape_f(file);
+ ide_drive_t *drive = tape->drive;
+ ssize_t retval, actually_written = 0;
+
+ /* The drive is write protected. */
+ if (tape->write_prot)
+ return -EACCES;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 3)
+ printk(KERN_INFO "ide-tape: Reached idetape_chrdev_write, "
+ "count %Zd\n", count);
+#endif /* IDETAPE_DEBUG_LOG */
+
+ /* Initialize write operation */
+ if (tape->chrdev_direction != idetape_direction_write) {
+ if (tape->chrdev_direction == idetape_direction_read)
+ idetape_discard_read_pipeline(drive, 1);
+#if IDETAPE_DEBUG_BUGS
+ if (tape->merge_stage || tape->merge_stage_size) {
+ printk(KERN_ERR "ide-tape: merge_stage_size "
+ "should be 0 now\n");
+ tape->merge_stage_size = 0;
+ }
+#endif /* IDETAPE_DEBUG_BUGS */
+ if ((tape->merge_stage = __idetape_kmalloc_stage(tape, 0, 0)) == NULL)
+ return -ENOMEM;
+ tape->chrdev_direction = idetape_direction_write;
+ idetape_init_merge_stage(tape);
+
+ /*
+ * Issue a write 0 command to ensure that DSC handshake
+ * is switched from completion mode to buffer available
+ * mode.
+ * No point in issuing this if DSC overlap isn't supported,
+ * some drives (Seagate STT3401A) will return an error.
+ */
+ if (drive->dsc_overlap) {
+ retval = idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, 0, tape->merge_stage->bh);
+ if (retval < 0) {
+ __idetape_kfree_stage(tape->merge_stage);
+ tape->merge_stage = NULL;
+ tape->chrdev_direction = idetape_direction_none;
+ return retval;
+ }
+ }
+ }
+ if (count == 0)
+ return (0);
+ if (tape->restart_speed_control_req)
+ idetape_restart_speed_control(drive);
+ if (tape->merge_stage_size) {
+#if IDETAPE_DEBUG_BUGS
+ if (tape->merge_stage_size >= tape->stage_size) {
+ printk(KERN_ERR "ide-tape: bug: merge buffer too big\n");
+ tape->merge_stage_size = 0;
+ }
+#endif /* IDETAPE_DEBUG_BUGS */
+ actually_written = min((unsigned int)(tape->stage_size - tape->merge_stage_size), (unsigned int)count);
+ idetape_copy_stage_from_user(tape, tape->merge_stage, buf, actually_written);
+ buf += actually_written;
+ tape->merge_stage_size += actually_written;
+ count -= actually_written;
+
+ if (tape->merge_stage_size == tape->stage_size) {
+ tape->merge_stage_size = 0;
+ retval = idetape_add_chrdev_write_request(drive, tape->capabilities.ctl);
+ if (retval <= 0)
+ return (retval);
+ }
+ }
+ while (count >= tape->stage_size) {
+ idetape_copy_stage_from_user(tape, tape->merge_stage, buf, tape->stage_size);
+ buf += tape->stage_size;
+ count -= tape->stage_size;
+ retval = idetape_add_chrdev_write_request(drive, tape->capabilities.ctl);
+ actually_written += tape->stage_size;
+ if (retval <= 0)
+ return (retval);
+ }
+ if (count) {
+ actually_written += count;
+ idetape_copy_stage_from_user(tape, tape->merge_stage, buf, count);
+ tape->merge_stage_size += count;
+ }
+ return (actually_written);
+}
+
+static int idetape_write_filemark (ide_drive_t *drive)
+{
+ idetape_pc_t pc;
+
+ /* Write a filemark */
+ idetape_create_write_filemark_cmd(drive, &pc, 1);
+ if (idetape_queue_pc_tail(drive, &pc)) {
+ printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
+ return -EIO;
+ }
+ return 0;
+}
+
+/*
+ * idetape_mtioctop is called from idetape_chrdev_ioctl when
+ * the general mtio MTIOCTOP ioctl is requested.
+ *
+ * We currently support the following mtio.h operations:
+ *
+ * MTFSF - Space over mt_count filemarks in the positive direction.
+ * The tape is positioned after the last spaced filemark.
+ *
+ * MTFSFM - Same as MTFSF, but the tape is positioned before the
+ * last filemark.
+ *
+ * MTBSF - Steps background over mt_count filemarks, tape is
+ * positioned before the last filemark.
+ *
+ * MTBSFM - Like MTBSF, only tape is positioned after the last filemark.
+ *
+ * Note:
+ *
+ * MTBSF and MTBSFM are not supported when the tape doesn't
+ * support spacing over filemarks in the reverse direction.
+ * In this case, MTFSFM is also usually not supported (it is
+ * supported in the rare case in which we crossed the filemark
+ * during our read-ahead pipelined operation mode).
+ *
+ * MTWEOF - Writes mt_count filemarks. Tape is positioned after
+ * the last written filemark.
+ *
+ * MTREW - Rewinds tape.
+ *
+ * MTLOAD - Loads the tape.
+ *
+ * MTOFFL - Puts the tape drive "Offline": Rewinds the tape and
+ * MTUNLOAD prevents further access until the media is replaced.
+ *
+ * MTNOP - Flushes tape buffers.
+ *
+ * MTRETEN - Retension media. This typically consists of one end
+ * to end pass on the media.
+ *
+ * MTEOM - Moves to the end of recorded data.
+ *
+ * MTERASE - Erases tape.
+ *
+ * MTSETBLK - Sets the user block size to mt_count bytes. If
+ * mt_count is 0, we will attempt to autodetect
+ * the block size.
+ *
+ * MTSEEK - Positions the tape in a specific block number, where
+ * each block is assumed to contain which user_block_size
+ * bytes.
+ *
+ * MTSETPART - Switches to another tape partition.
+ *
+ * MTLOCK - Locks the tape door.
+ *
+ * MTUNLOCK - Unlocks the tape door.
+ *
+ * The following commands are currently not supported:
+ *
+ * MTFSS, MTBSS, MTWSM, MTSETDENSITY,
+ * MTSETDRVBUFFER, MT_ST_BOOLEANS, MT_ST_WRITE_THRESHOLD.
+ */
+static int idetape_mtioctop (ide_drive_t *drive,short mt_op,int mt_count)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ idetape_pc_t pc;
+ int i,retval;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 1)
+ printk(KERN_INFO "ide-tape: Handling MTIOCTOP ioctl: "
+ "mt_op=%d, mt_count=%d\n", mt_op, mt_count);
+#endif /* IDETAPE_DEBUG_LOG */
+ /*
+ * Commands which need our pipelined read-ahead stages.
+ */
+ switch (mt_op) {
+ case MTFSF:
+ case MTFSFM:
+ case MTBSF:
+ case MTBSFM:
+ if (!mt_count)
+ return (0);
+ return (idetape_space_over_filemarks(drive,mt_op,mt_count));
+ default:
+ break;
+ }
+ switch (mt_op) {
+ case MTWEOF:
+ if (tape->write_prot)
+ return -EACCES;
+ idetape_discard_read_pipeline(drive, 1);
+ for (i = 0; i < mt_count; i++) {
+ retval = idetape_write_filemark(drive);
+ if (retval)
+ return retval;
+ }
+ return (0);
+ case MTREW:
+ idetape_discard_read_pipeline(drive, 0);
+ if (idetape_rewind_tape(drive))
+ return -EIO;
+ return 0;
+ case MTLOAD:
+ idetape_discard_read_pipeline(drive, 0);
+ idetape_create_load_unload_cmd(drive, &pc, IDETAPE_LU_LOAD_MASK);
+ return (idetape_queue_pc_tail(drive, &pc));
+ case MTUNLOAD:
+ case MTOFFL:
+ /*
+ * If door is locked, attempt to unlock before
+ * attempting to eject.
+ */
+ if (tape->door_locked) {
+ if (idetape_create_prevent_cmd(drive, &pc, 0))
+ if (!idetape_queue_pc_tail(drive, &pc))
+ tape->door_locked = DOOR_UNLOCKED;
+ }
+ idetape_discard_read_pipeline(drive, 0);
+ idetape_create_load_unload_cmd(drive, &pc,!IDETAPE_LU_LOAD_MASK);
+ retval = idetape_queue_pc_tail(drive, &pc);
+ if (!retval)
+ clear_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags);
+ return retval;
+ case MTNOP:
+ idetape_discard_read_pipeline(drive, 0);
+ return (idetape_flush_tape_buffers(drive));
+ case MTRETEN:
+ idetape_discard_read_pipeline(drive, 0);
+ idetape_create_load_unload_cmd(drive, &pc,IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
+ return (idetape_queue_pc_tail(drive, &pc));
+ case MTEOM:
+ idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
+ return (idetape_queue_pc_tail(drive, &pc));
+ case MTERASE:
+ (void) idetape_rewind_tape(drive);
+ idetape_create_erase_cmd(&pc);
+ return (idetape_queue_pc_tail(drive, &pc));
+ case MTSETBLK:
+ if (mt_count) {
+ if (mt_count < tape->tape_block_size || mt_count % tape->tape_block_size)
+ return -EIO;
+ tape->user_bs_factor = mt_count / tape->tape_block_size;
+ clear_bit(IDETAPE_DETECT_BS, &tape->flags);
+ } else
+ set_bit(IDETAPE_DETECT_BS, &tape->flags);
+ return 0;
+ case MTSEEK:
+ idetape_discard_read_pipeline(drive, 0);
+ return idetape_position_tape(drive, mt_count * tape->user_bs_factor, tape->partition, 0);
+ case MTSETPART:
+ idetape_discard_read_pipeline(drive, 0);
+ return (idetape_position_tape(drive, 0, mt_count, 0));
+ case MTFSR:
+ case MTBSR:
+ case MTLOCK:
+ if (!idetape_create_prevent_cmd(drive, &pc, 1))
+ return 0;
+ retval = idetape_queue_pc_tail(drive, &pc);
+ if (retval) return retval;
+ tape->door_locked = DOOR_EXPLICITLY_LOCKED;
+ return 0;
+ case MTUNLOCK:
+ if (!idetape_create_prevent_cmd(drive, &pc, 0))
+ return 0;
+ retval = idetape_queue_pc_tail(drive, &pc);
+ if (retval) return retval;
+ tape->door_locked = DOOR_UNLOCKED;
+ return 0;
+ default:
+ printk(KERN_ERR "ide-tape: MTIO operation %d not "
+ "supported\n", mt_op);
+ return (-EIO);
+ }
+}
+
+/*
+ * Our character device ioctls.
+ *
+ * General mtio.h magnetic io commands are supported here, and not in
+ * the corresponding block interface.
+ *
+ * The following ioctls are supported:
+ *
+ * MTIOCTOP - Refer to idetape_mtioctop for detailed description.
+ *
+ * MTIOCGET - The mt_dsreg field in the returned mtget structure
+ * will be set to (user block size in bytes <<
+ * MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK.
+ *
+ * The mt_blkno is set to the current user block number.
+ * The other mtget fields are not supported.
+ *
+ * MTIOCPOS - The current tape "block position" is returned. We
+ * assume that each block contains user_block_size
+ * bytes.
+ *
+ * Our own ide-tape ioctls are supported on both interfaces.
+ */
+static int idetape_chrdev_ioctl (struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct ide_tape_obj *tape = ide_tape_f(file);
+ ide_drive_t *drive = tape->drive;
+ struct mtop mtop;
+ struct mtget mtget;
+ struct mtpos mtpos;
+ int block_offset = 0, position = tape->first_frame_position;
+ void __user *argp = (void __user *)arg;
+
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 3)
+ printk(KERN_INFO "ide-tape: Reached idetape_chrdev_ioctl, "
+ "cmd=%u\n", cmd);
+#endif /* IDETAPE_DEBUG_LOG */
+
+ tape->restart_speed_control_req = 1;
+ if (tape->chrdev_direction == idetape_direction_write) {
+ idetape_empty_write_pipeline(drive);
+ idetape_flush_tape_buffers(drive);
+ }
+ if (cmd == MTIOCGET || cmd == MTIOCPOS) {
+ block_offset = idetape_pipeline_size(drive) / (tape->tape_block_size * tape->user_bs_factor);
+ if ((position = idetape_read_position(drive)) < 0)
+ return -EIO;
+ }
+ switch (cmd) {
+ case MTIOCTOP:
+ if (copy_from_user(&mtop, argp, sizeof (struct mtop)))
+ return -EFAULT;
+ return (idetape_mtioctop(drive,mtop.mt_op,mtop.mt_count));
+ case MTIOCGET:
+ memset(&mtget, 0, sizeof (struct mtget));
+ mtget.mt_type = MT_ISSCSI2;
+ mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
+ mtget.mt_dsreg = ((tape->tape_block_size * tape->user_bs_factor) << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;
+ if (tape->drv_write_prot) {
+ mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
+ }
+ if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
+ return -EFAULT;
+ return 0;
+ case MTIOCPOS:
+ mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
+ if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
+ return -EFAULT;
+ return 0;
+ default:
+ if (tape->chrdev_direction == idetape_direction_read)
+ idetape_discard_read_pipeline(drive, 1);
+ return idetape_blkdev_ioctl(drive, cmd, arg);
+ }
+}
+
+static void idetape_get_blocksize_from_block_descriptor(ide_drive_t *drive);
+
+/*
+ * Our character device open function.
+ */
+static int idetape_chrdev_open (struct inode *inode, struct file *filp)
+{
+ unsigned int minor = iminor(inode), i = minor & ~0xc0;
+ ide_drive_t *drive;
+ idetape_tape_t *tape;
+ idetape_pc_t pc;
+ int retval;
+
+ /*
+ * We really want to do nonseekable_open(inode, filp); here, but some
+ * versions of tar incorrectly call lseek on tapes and bail out if that
+ * fails. So we disallow pread() and pwrite(), but permit lseeks.
+ */
+ filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);
+
+#if IDETAPE_DEBUG_LOG
+ printk(KERN_INFO "ide-tape: Reached idetape_chrdev_open\n");
+#endif /* IDETAPE_DEBUG_LOG */
+
+ if (i >= MAX_HWIFS * MAX_DRIVES)
+ return -ENXIO;
+
+ if (!(tape = ide_tape_chrdev_get(i)))
+ return -ENXIO;
+
+ drive = tape->drive;
+
+ filp->private_data = tape;
+
+ if (test_and_set_bit(IDETAPE_BUSY, &tape->flags)) {
+ retval = -EBUSY;
+ goto out_put_tape;
+ }
+
+ retval = idetape_wait_ready(drive, 60 * HZ);
+ if (retval) {
+ clear_bit(IDETAPE_BUSY, &tape->flags);
+ printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
+ goto out_put_tape;
+ }
+
+ idetape_read_position(drive);
+ if (!test_bit(IDETAPE_ADDRESS_VALID, &tape->flags))
+ (void)idetape_rewind_tape(drive);
+
+ if (tape->chrdev_direction != idetape_direction_read)
+ clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
+
+ /* Read block size and write protect status from drive. */
+ idetape_get_blocksize_from_block_descriptor(drive);
+
+ /* Set write protect flag if device is opened as read-only. */
+ if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
+ tape->write_prot = 1;
+ else
+ tape->write_prot = tape->drv_write_prot;
+
+ /* Make sure drive isn't write protected if user wants to write. */
+ if (tape->write_prot) {
+ if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
+ (filp->f_flags & O_ACCMODE) == O_RDWR) {
+ clear_bit(IDETAPE_BUSY, &tape->flags);
+ retval = -EROFS;
+ goto out_put_tape;
+ }
+ }
+
+ /*
+ * Lock the tape drive door so user can't eject.
+ */
+ if (tape->chrdev_direction == idetape_direction_none) {
+ if (idetape_create_prevent_cmd(drive, &pc, 1)) {
+ if (!idetape_queue_pc_tail(drive, &pc)) {
+ if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
+ tape->door_locked = DOOR_LOCKED;
+ }
+ }
+ }
+ idetape_restart_speed_control(drive);
+ tape->restart_speed_control_req = 0;
+ return 0;
+
+out_put_tape:
+ ide_tape_put(tape);
+ return retval;
+}
+
+static void idetape_write_release (ide_drive_t *drive, unsigned int minor)
+{
+ idetape_tape_t *tape = drive->driver_data;
+
+ idetape_empty_write_pipeline(drive);
+ tape->merge_stage = __idetape_kmalloc_stage(tape, 1, 0);
+ if (tape->merge_stage != NULL) {
+ idetape_pad_zeros(drive, tape->tape_block_size * (tape->user_bs_factor - 1));
+ __idetape_kfree_stage(tape->merge_stage);
+ tape->merge_stage = NULL;
+ }
+ idetape_write_filemark(drive);
+ idetape_flush_tape_buffers(drive);
+ idetape_flush_tape_buffers(drive);
+}
+
+/*
+ * Our character device release function.
+ */
+static int idetape_chrdev_release (struct inode *inode, struct file *filp)
+{
+ struct ide_tape_obj *tape = ide_tape_f(filp);
+ ide_drive_t *drive = tape->drive;
+ idetape_pc_t pc;
+ unsigned int minor = iminor(inode);
+
+ lock_kernel();
+ tape = drive->driver_data;
+#if IDETAPE_DEBUG_LOG
+ if (tape->debug_level >= 3)
+ printk(KERN_INFO "ide-tape: Reached idetape_chrdev_release\n");
+#endif /* IDETAPE_DEBUG_LOG */
+
+ if (tape->chrdev_direction == idetape_direction_write)
+ idetape_write_release(drive, minor);
+ if (tape->chrdev_direction == idetape_direction_read) {
+ if (minor < 128)
+ idetape_discard_read_pipeline(drive, 1);
+ else
+ idetape_wait_for_pipeline(drive);
+ }
+ if (tape->cache_stage != NULL) {
+ __idetape_kfree_stage(tape->cache_stage);
+ tape->cache_stage = NULL;
+ }
+ if (minor < 128 && test_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags))
+ (void) idetape_rewind_tape(drive);
+ if (tape->chrdev_direction == idetape_direction_none) {
+ if (tape->door_locked == DOOR_LOCKED) {
+ if (idetape_create_prevent_cmd(drive, &pc, 0)) {
+ if (!idetape_queue_pc_tail(drive, &pc))
+ tape->door_locked = DOOR_UNLOCKED;
+ }
+ }
+ }
+ clear_bit(IDETAPE_BUSY, &tape->flags);
+ ide_tape_put(tape);
+ unlock_kernel();
+ return 0;
+}
+
+/*
+ * idetape_identify_device is called to check the contents of the
+ * ATAPI IDENTIFY command results. We return:
+ *
+ * 1 If the tape can be supported by us, based on the information
+ * we have so far.
+ *
+ * 0 If this tape driver is not currently supported by us.
+ */
+static int idetape_identify_device (ide_drive_t *drive)
+{
+ struct idetape_id_gcw gcw;
+ struct hd_driveid *id = drive->id;
+#if IDETAPE_DEBUG_INFO
+ unsigned short mask,i;
+#endif /* IDETAPE_DEBUG_INFO */
+
+ if (drive->id_read == 0)
+ return 1;
+
+ *((unsigned short *) &gcw) = id->config;
+
+#if IDETAPE_DEBUG_INFO
+ printk(KERN_INFO "ide-tape: Dumping ATAPI Identify Device tape parameters\n");
+ printk(KERN_INFO "ide-tape: Protocol Type: ");
+ switch (gcw.protocol) {
+ case 0: case 1: printk("ATA\n");break;
+ case 2: printk("ATAPI\n");break;
+ case 3: printk("Reserved (Unknown to ide-tape)\n");break;
+ }
+ printk(KERN_INFO "ide-tape: Device Type: %x - ",gcw.device_type);
+ switch (gcw.device_type) {
+ case 0: printk("Direct-access Device\n");break;
+ case 1: printk("Streaming Tape Device\n");break;
+ case 2: case 3: case 4: printk("Reserved\n");break;
+ case 5: printk("CD-ROM Device\n");break;
+ case 6: printk("Reserved\n");
+ case 7: printk("Optical memory Device\n");break;
+ case 0x1f: printk("Unknown or no Device type\n");break;
+ default: printk("Reserved\n");
+ }
+ printk(KERN_INFO "ide-tape: Removable: %s",gcw.removable ? "Yes\n":"No\n");
+ printk(KERN_INFO "ide-tape: Command Packet DRQ Type: ");
+ switch (gcw.drq_type) {
+ case 0: printk("Microprocessor DRQ\n");break;
+ case 1: printk("Interrupt DRQ\n");break;
+ case 2: printk("Accelerated DRQ\n");break;
+ case 3: printk("Reserved\n");break;
+ }
+ printk(KERN_INFO "ide-tape: Command Packet Size: ");
+ switch (gcw.packet_size) {
+ case 0: printk("12 bytes\n");break;
+ case 1: printk("16 bytes\n");break;
+ default: printk("Reserved\n");break;
+ }
+ printk(KERN_INFO "ide-tape: Model: %.40s\n",id->model);
+ printk(KERN_INFO "ide-tape: Firmware Revision: %.8s\n",id->fw_rev);
+ printk(KERN_INFO "ide-tape: Serial Number: %.20s\n",id->serial_no);
+ printk(KERN_INFO "ide-tape: Write buffer size: %d bytes\n",id->buf_size*512);
+ printk(KERN_INFO "ide-tape: DMA: %s",id->capability & 0x01 ? "Yes\n":"No\n");
+ printk(KERN_INFO "ide-tape: LBA: %s",id->capability & 0x02 ? "Yes\n":"No\n");
+ printk(KERN_INFO "ide-tape: IORDY can be disabled: %s",id->capability & 0x04 ? "Yes\n":"No\n");
+ printk(KERN_INFO "ide-tape: IORDY supported: %s",id->capability & 0x08 ? "Yes\n":"Unknown\n");
+ printk(KERN_INFO "ide-tape: ATAPI overlap supported: %s",id->capability & 0x20 ? "Yes\n":"No\n");
+ printk(KERN_INFO "ide-tape: PIO Cycle Timing Category: %d\n",id->tPIO);
+ printk(KERN_INFO "ide-tape: DMA Cycle Timing Category: %d\n",id->tDMA);
+ printk(KERN_INFO "ide-tape: Single Word DMA supported modes: ");
+ for (i=0,mask=1;i<8;i++,mask=mask << 1) {
+ if (id->dma_1word & mask)
+ printk("%d ",i);
+ if (id->dma_1word & (mask << 8))
+ printk("(active) ");
+ }
+ printk("\n");
+ printk(KERN_INFO "ide-tape: Multi Word DMA supported modes: ");
+ for (i=0,mask=1;i<8;i++,mask=mask << 1) {
+ if (id->dma_mword & mask)
+ printk("%d ",i);
+ if (id->dma_mword & (mask << 8))
+ printk("(active) ");
+ }
+ printk("\n");
+ if (id->field_valid & 0x0002) {
+ printk(KERN_INFO "ide-tape: Enhanced PIO Modes: %s\n",
+ id->eide_pio_modes & 1 ? "Mode 3":"None");
+ printk(KERN_INFO "ide-tape: Minimum Multi-word DMA cycle per word: ");
+ if (id->eide_dma_min == 0)
+ printk("Not supported\n");
+ else
+ printk("%d ns\n",id->eide_dma_min);
+
+ printk(KERN_INFO "ide-tape: Manufacturer\'s Recommended Multi-word cycle: ");
+ if (id->eide_dma_time == 0)
+ printk("Not supported\n");
+ else
+ printk("%d ns\n",id->eide_dma_time);
+
+ printk(KERN_INFO "ide-tape: Minimum PIO cycle without IORDY: ");
+ if (id->eide_pio == 0)
+ printk("Not supported\n");
+ else
+ printk("%d ns\n",id->eide_pio);
+
+ printk(KERN_INFO "ide-tape: Minimum PIO cycle with IORDY: ");
+ if (id->eide_pio_iordy == 0)
+ printk("Not supported\n");
+ else
+ printk("%d ns\n",id->eide_pio_iordy);
+
+ } else
+ printk(KERN_INFO "ide-tape: According to the device, fields 64-70 are not valid.\n");
+#endif /* IDETAPE_DEBUG_INFO */
+
+ /* Check that we can support this device */
+
+ if (gcw.protocol !=2 )
+ printk(KERN_ERR "ide-tape: Protocol is not ATAPI\n");
+ else if (gcw.device_type != 1)
+ printk(KERN_ERR "ide-tape: Device type is not set to tape\n");
+ else if (!gcw.removable)
+ printk(KERN_ERR "ide-tape: The removable flag is not set\n");
+ else if (gcw.packet_size != 0) {
+ printk(KERN_ERR "ide-tape: Packet size is not 12 bytes long\n");
+ if (gcw.packet_size == 1)
+ printk(KERN_ERR "ide-tape: Sorry, padding to 16 bytes is still not supported\n");
+ } else
+ return 1;
+ return 0;
+}
+
+/*
+ * Use INQUIRY to get the firmware revision
+ */
+static void idetape_get_inquiry_results (ide_drive_t *drive)
+{
+ char *r;
+ idetape_tape_t *tape = drive->driver_data;
+ idetape_pc_t pc;
+ idetape_inquiry_result_t *inquiry;
+
+ idetape_create_inquiry_cmd(&pc);
+ if (idetape_queue_pc_tail(drive, &pc)) {
+ printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n", tape->name);
+ return;
+ }
+ inquiry = (idetape_inquiry_result_t *) pc.buffer;
+ memcpy(tape->vendor_id, inquiry->vendor_id, 8);
+ memcpy(tape->product_id, inquiry->product_id, 16);
+ memcpy(tape->firmware_revision, inquiry->revision_level, 4);
+ ide_fixstring(tape->vendor_id, 10, 0);
+ ide_fixstring(tape->product_id, 18, 0);
+ ide_fixstring(tape->firmware_revision, 6, 0);
+ r = tape->firmware_revision;
+ if (*(r + 1) == '.')
+ tape->firmware_revision_num = (*r - '0') * 100 + (*(r + 2) - '0') * 10 + *(r + 3) - '0';
+ printk(KERN_INFO "ide-tape: %s <-> %s: %s %s rev %s\n", drive->name, tape->name, tape->vendor_id, tape->product_id, tape->firmware_revision);
+}
+
+/*
+ * idetape_get_mode_sense_results asks the tape about its various
+ * parameters. In particular, we will adjust our data transfer buffer
+ * size to the recommended value as returned by the tape.
+ */
+static void idetape_get_mode_sense_results (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ idetape_pc_t pc;
+ idetape_mode_parameter_header_t *header;
+ idetape_capabilities_page_t *capabilities;
+
+ idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
+ if (idetape_queue_pc_tail(drive, &pc)) {
+ printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming some default values\n");
+ tape->tape_block_size = 512;
+ tape->capabilities.ctl = 52;
+ tape->capabilities.speed = 450;
+ tape->capabilities.buffer_size = 6 * 52;
+ return;
+ }
+ header = (idetape_mode_parameter_header_t *) pc.buffer;
+ capabilities = (idetape_capabilities_page_t *) (pc.buffer + sizeof(idetape_mode_parameter_header_t) + header->bdl);
+
+ capabilities->max_speed = ntohs(capabilities->max_speed);
+ capabilities->ctl = ntohs(capabilities->ctl);
+ capabilities->speed = ntohs(capabilities->speed);
+ capabilities->buffer_size = ntohs(capabilities->buffer_size);
+
+ if (!capabilities->speed) {
+ printk(KERN_INFO "ide-tape: %s: overriding capabilities->speed (assuming 650KB/sec)\n", drive->name);
+ capabilities->speed = 650;
+ }
+ if (!capabilities->max_speed) {
+ printk(KERN_INFO "ide-tape: %s: overriding capabilities->max_speed (assuming 650KB/sec)\n", drive->name);
+ capabilities->max_speed = 650;
+ }
+
+ tape->capabilities = *capabilities; /* Save us a copy */
+ if (capabilities->blk512)
+ tape->tape_block_size = 512;
+ else if (capabilities->blk1024)
+ tape->tape_block_size = 1024;
+
+#if IDETAPE_DEBUG_INFO
+ printk(KERN_INFO "ide-tape: Dumping the results of the MODE SENSE packet command\n");
+ printk(KERN_INFO "ide-tape: Mode Parameter Header:\n");
+ printk(KERN_INFO "ide-tape: Mode Data Length - %d\n",header->mode_data_length);
+ printk(KERN_INFO "ide-tape: Medium Type - %d\n",header->medium_type);
+ printk(KERN_INFO "ide-tape: Device Specific Parameter - %d\n",header->dsp);
+ printk(KERN_INFO "ide-tape: Block Descriptor Length - %d\n",header->bdl);
+
+ printk(KERN_INFO "ide-tape: Capabilities and Mechanical Status Page:\n");
+ printk(KERN_INFO "ide-tape: Page code - %d\n",capabilities->page_code);
+ printk(KERN_INFO "ide-tape: Page length - %d\n",capabilities->page_length);
+ printk(KERN_INFO "ide-tape: Read only - %s\n",capabilities->ro ? "Yes":"No");
+ printk(KERN_INFO "ide-tape: Supports reverse space - %s\n",capabilities->sprev ? "Yes":"No");
+ printk(KERN_INFO "ide-tape: Supports erase initiated formatting - %s\n",capabilities->efmt ? "Yes":"No");
+ printk(KERN_INFO "ide-tape: Supports QFA two Partition format - %s\n",capabilities->qfa ? "Yes":"No");
+ printk(KERN_INFO "ide-tape: Supports locking the medium - %s\n",capabilities->lock ? "Yes":"No");
+ printk(KERN_INFO "ide-tape: The volume is currently locked - %s\n",capabilities->locked ? "Yes":"No");
+ printk(KERN_INFO "ide-tape: The device defaults in the prevent state - %s\n",capabilities->prevent ? "Yes":"No");
+ printk(KERN_INFO "ide-tape: Supports ejecting the medium - %s\n",capabilities->eject ? "Yes":"No");
+ printk(KERN_INFO "ide-tape: Supports error correction - %s\n",capabilities->ecc ? "Yes":"No");
+ printk(KERN_INFO "ide-tape: Supports data compression - %s\n",capabilities->cmprs ? "Yes":"No");
+ printk(KERN_INFO "ide-tape: Supports 512 bytes block size - %s\n",capabilities->blk512 ? "Yes":"No");
+ printk(KERN_INFO "ide-tape: Supports 1024 bytes block size - %s\n",capabilities->blk1024 ? "Yes":"No");
+ printk(KERN_INFO "ide-tape: Supports 32768 bytes block size / Restricted byte count for PIO transfers - %s\n",capabilities->blk32768 ? "Yes":"No");
+ printk(KERN_INFO "ide-tape: Maximum supported speed in KBps - %d\n",capabilities->max_speed);
+ printk(KERN_INFO "ide-tape: Continuous transfer limits in blocks - %d\n",capabilities->ctl);
+ printk(KERN_INFO "ide-tape: Current speed in KBps - %d\n",capabilities->speed);
+ printk(KERN_INFO "ide-tape: Buffer size - %d\n",capabilities->buffer_size*512);
+#endif /* IDETAPE_DEBUG_INFO */
+}
+
+/*
+ * ide_get_blocksize_from_block_descriptor does a mode sense page 0 with block descriptor
+ * and if it succeeds sets the tape block size with the reported value
+ */
+static void idetape_get_blocksize_from_block_descriptor(ide_drive_t *drive)
+{
+
+ idetape_tape_t *tape = drive->driver_data;
+ idetape_pc_t pc;
+ idetape_mode_parameter_header_t *header;
+ idetape_parameter_block_descriptor_t *block_descrp;
+
+ idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
+ if (idetape_queue_pc_tail(drive, &pc)) {
+ printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
+ if (tape->tape_block_size == 0) {
+ printk(KERN_WARNING "ide-tape: Cannot deal with zero block size, assume 32k\n");
+ tape->tape_block_size = 32768;
+ }
+ return;
+ }
+ header = (idetape_mode_parameter_header_t *) pc.buffer;
+ block_descrp = (idetape_parameter_block_descriptor_t *) (pc.buffer + sizeof(idetape_mode_parameter_header_t));
+ tape->tape_block_size =( block_descrp->length[0]<<16) + (block_descrp->length[1]<<8) + block_descrp->length[2];
+ tape->drv_write_prot = (header->dsp & 0x80) >> 7;
+
+#if IDETAPE_DEBUG_INFO
+ printk(KERN_INFO "ide-tape: Adjusted block size - %d\n", tape->tape_block_size);
+#endif /* IDETAPE_DEBUG_INFO */
+}
+static void idetape_add_settings (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+
+/*
+ * drive setting name read/write ioctl ioctl data type min max mul_factor div_factor data pointer set function
+ */
+ ide_add_setting(drive, "buffer", SETTING_READ, -1, -1, TYPE_SHORT, 0, 0xffff, 1, 2, &tape->capabilities.buffer_size, NULL);
+ ide_add_setting(drive, "pipeline_min", SETTING_RW, -1, -1, TYPE_INT, 1, 0xffff, tape->stage_size / 1024, 1, &tape->min_pipeline, NULL);
+ ide_add_setting(drive, "pipeline", SETTING_RW, -1, -1, TYPE_INT, 1, 0xffff, tape->stage_size / 1024, 1, &tape->max_stages, NULL);
+ ide_add_setting(drive, "pipeline_max", SETTING_RW, -1, -1, TYPE_INT, 1, 0xffff, tape->stage_size / 1024, 1, &tape->max_pipeline, NULL);
+ ide_add_setting(drive, "pipeline_used",SETTING_READ, -1, -1, TYPE_INT, 0, 0xffff, tape->stage_size / 1024, 1, &tape->nr_stages, NULL);
+ ide_add_setting(drive, "pipeline_pending",SETTING_READ,-1, -1, TYPE_INT, 0, 0xffff, tape->stage_size / 1024, 1, &tape->nr_pending_stages, NULL);
+ ide_add_setting(drive, "speed", SETTING_READ, -1, -1, TYPE_SHORT, 0, 0xffff, 1, 1, &tape->capabilities.speed, NULL);
+ ide_add_setting(drive, "stage", SETTING_READ, -1, -1, TYPE_INT, 0, 0xffff, 1, 1024, &tape->stage_size, NULL);
+ ide_add_setting(drive, "tdsc", SETTING_RW, -1, -1, TYPE_INT, IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX, 1000, HZ, &tape->best_dsc_rw_frequency, NULL);
+ ide_add_setting(drive, "dsc_overlap", SETTING_RW, -1, -1, TYPE_BYTE, 0, 1, 1, 1, &drive->dsc_overlap, NULL);
+ ide_add_setting(drive, "pipeline_head_speed_c",SETTING_READ, -1, -1, TYPE_INT, 0, 0xffff, 1, 1, &tape->controlled_pipeline_head_speed, NULL);
+ ide_add_setting(drive, "pipeline_head_speed_u",SETTING_READ, -1, -1, TYPE_INT, 0, 0xffff, 1, 1, &tape->uncontrolled_pipeline_head_speed, NULL);
+ ide_add_setting(drive, "avg_speed", SETTING_READ, -1, -1, TYPE_INT, 0, 0xffff, 1, 1, &tape->avg_speed, NULL);
+ ide_add_setting(drive, "debug_level",SETTING_RW, -1, -1, TYPE_INT, 0, 0xffff, 1, 1, &tape->debug_level, NULL);
+}
+
+/*
+ * ide_setup is called to:
+ *
+ * 1. Initialize our various state variables.
+ * 2. Ask the tape for its capabilities.
+ * 3. Allocate a buffer which will be used for data
+ * transfer. The buffer size is chosen based on
+ * the recommendation which we received in step (2).
+ *
+ * Note that at this point ide.c already assigned us an irq, so that
+ * we can queue requests here and wait for their completion.
+ */
+static void idetape_setup (ide_drive_t *drive, idetape_tape_t *tape, int minor)
+{
+ unsigned long t1, tmid, tn, t;
+ int speed;
+ struct idetape_id_gcw gcw;
+ int stage_size;
+ struct sysinfo si;
+
+ spin_lock_init(&tape->spinlock);
+ drive->dsc_overlap = 1;
+#ifdef CONFIG_BLK_DEV_IDEPCI
+ if (HWIF(drive)->pci_dev != NULL) {
+ /*
+ * These two ide-pci host adapters appear to need DSC overlap disabled.
+ * This probably needs further analysis.
+ */
+ if ((HWIF(drive)->pci_dev->device == PCI_DEVICE_ID_ARTOP_ATP850UF) ||
+ (HWIF(drive)->pci_dev->device == PCI_DEVICE_ID_TTI_HPT343)) {
+ printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n", tape->name);
+ drive->dsc_overlap = 0;
+ }
+ }
+#endif /* CONFIG_BLK_DEV_IDEPCI */
+ /* Seagate Travan drives do not support DSC overlap. */
+ if (strstr(drive->id->model, "Seagate STT3401"))
+ drive->dsc_overlap = 0;
+ tape->minor = minor;
+ tape->name[0] = 'h';
+ tape->name[1] = 't';
+ tape->name[2] = '0' + minor;
+ tape->chrdev_direction = idetape_direction_none;
+ tape->pc = tape->pc_stack;
+ tape->max_insert_speed = 10000;
+ tape->speed_control = 1;
+ *((unsigned short *) &gcw) = drive->id->config;
+ if (gcw.drq_type == 1)
+ set_bit(IDETAPE_DRQ_INTERRUPT, &tape->flags);
+
+ tape->min_pipeline = tape->max_pipeline = tape->max_stages = 10;
+
+ idetape_get_inquiry_results(drive);
+ idetape_get_mode_sense_results(drive);
+ idetape_get_blocksize_from_block_descriptor(drive);
+ tape->user_bs_factor = 1;
+ tape->stage_size = tape->capabilities.ctl * tape->tape_block_size;
+ while (tape->stage_size > 0xffff) {
+ printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
+ tape->capabilities.ctl /= 2;
+ tape->stage_size = tape->capabilities.ctl * tape->tape_block_size;
+ }
+ stage_size = tape->stage_size;
+ tape->pages_per_stage = stage_size / PAGE_SIZE;
+ if (stage_size % PAGE_SIZE) {
+ tape->pages_per_stage++;
+ tape->excess_bh_size = PAGE_SIZE - stage_size % PAGE_SIZE;
+ }
+
+ /*
+ * Select the "best" DSC read/write polling frequency
+ * and pipeline size.
+ */
+ speed = max(tape->capabilities.speed, tape->capabilities.max_speed);
+
+ tape->max_stages = speed * 1000 * 10 / tape->stage_size;
+
+ /*
+ * Limit memory use for pipeline to 10% of physical memory
+ */
+ si_meminfo(&si);
+ if (tape->max_stages * tape->stage_size > si.totalram * si.mem_unit / 10)
+ tape->max_stages = si.totalram * si.mem_unit / (10 * tape->stage_size);
+ tape->max_stages = min(tape->max_stages, IDETAPE_MAX_PIPELINE_STAGES);
+ tape->min_pipeline = min(tape->max_stages, IDETAPE_MIN_PIPELINE_STAGES);
+ tape->max_pipeline = min(tape->max_stages * 2, IDETAPE_MAX_PIPELINE_STAGES);
+ if (tape->max_stages == 0)
+ tape->max_stages = tape->min_pipeline = tape->max_pipeline = 1;
+
+ t1 = (tape->stage_size * HZ) / (speed * 1000);
+ tmid = (tape->capabilities.buffer_size * 32 * HZ) / (speed * 125);
+ tn = (IDETAPE_FIFO_THRESHOLD * tape->stage_size * HZ) / (speed * 1000);
+
+ if (tape->max_stages)
+ t = tn;
+ else
+ t = t1;
+
+ /*
+ * Ensure that the number we got makes sense; limit
+ * it within IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
+ */
+ tape->best_dsc_rw_frequency = max_t(unsigned long, min_t(unsigned long, t, IDETAPE_DSC_RW_MAX), IDETAPE_DSC_RW_MIN);
+ printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
+ "%dkB pipeline, %lums tDSC%s\n",
+ drive->name, tape->name, tape->capabilities.speed,
+ (tape->capabilities.buffer_size * 512) / tape->stage_size,
+ tape->stage_size / 1024,
+ tape->max_stages * tape->stage_size / 1024,
+ tape->best_dsc_rw_frequency * 1000 / HZ,
+ drive->using_dma ? ", DMA":"");
+
+ idetape_add_settings(drive);
+}
+
+static int idetape_cleanup (ide_drive_t *drive)
+{
+ idetape_tape_t *tape = drive->driver_data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ide_lock, flags);
+ if (test_bit(IDETAPE_BUSY, &tape->flags) || drive->usage ||
+ tape->first_stage != NULL || tape->merge_stage_size) {
+ spin_unlock_irqrestore(&ide_lock, flags);
+ return 1;
+ }
+
+ spin_unlock_irqrestore(&ide_lock, flags);
+ DRIVER(drive)->busy = 0;
+ (void) ide_unregister_subdriver(drive);
+
+ ide_unregister_region(tape->disk);
+
+ ide_tape_put(tape);
+
+ return 0;
+}
+
+static void ide_tape_release(struct kref *kref)
+{
+ struct ide_tape_obj *tape = to_ide_tape(kref);
+ ide_drive_t *drive = tape->drive;
+ struct gendisk *g = tape->disk;
+
+ drive->dsc_overlap = 0;
+ drive->driver_data = NULL;
+ devfs_remove("%s/mt", drive->devfs_name);
+ devfs_remove("%s/mtn", drive->devfs_name);
+ devfs_unregister_tape(g->number);
+ idetape_devs[tape->minor] = NULL;
+ g->private_data = NULL;
+ put_disk(g);
+ kfree(tape);
+}
+
+#ifdef CONFIG_PROC_FS
+
+static int proc_idetape_read_name
+ (char *page, char **start, off_t off, int count, int *eof, void *data)
+{
+ ide_drive_t *drive = (ide_drive_t *) data;
+ idetape_tape_t *tape = drive->driver_data;
+ char *out = page;
+ int len;
+
+ len = sprintf(out, "%s\n", tape->name);
+ PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
+}
+
+static ide_proc_entry_t idetape_proc[] = {
+ { "capacity", S_IFREG|S_IRUGO, proc_ide_read_capacity, NULL },
+ { "name", S_IFREG|S_IRUGO, proc_idetape_read_name, NULL },
+ { NULL, 0, NULL, NULL }
+};
+
+#else
+
+#define idetape_proc NULL
+
+#endif
+
+static int idetape_attach(ide_drive_t *drive);
+
+/*
+ * IDE subdriver functions, registered with ide.c
+ */
+static ide_driver_t idetape_driver = {
+ .owner = THIS_MODULE,
+ .name = "ide-tape",
+ .version = IDETAPE_VERSION,
+ .media = ide_tape,
+ .busy = 1,
+ .supports_dsc_overlap = 1,
+ .cleanup = idetape_cleanup,
+ .do_request = idetape_do_request,
+ .end_request = idetape_end_request,
+ .error = __ide_error,
+ .abort = __ide_abort,
+ .proc = idetape_proc,
+ .attach = idetape_attach,
+ .drives = LIST_HEAD_INIT(idetape_driver.drives),
+};
+
+/*
+ * Our character device supporting functions, passed to register_chrdev.
+ */
+static struct file_operations idetape_fops = {
+ .owner = THIS_MODULE,
+ .read = idetape_chrdev_read,
+ .write = idetape_chrdev_write,
+ .ioctl = idetape_chrdev_ioctl,
+ .open = idetape_chrdev_open,
+ .release = idetape_chrdev_release,
+};
+
+static int idetape_open(struct inode *inode, struct file *filp)
+{
+ struct gendisk *disk = inode->i_bdev->bd_disk;
+ struct ide_tape_obj *tape;
+ ide_drive_t *drive;
+
+ if (!(tape = ide_tape_get(disk)))
+ return -ENXIO;
+
+ drive = tape->drive;
+
+ drive->usage++;
+
+ return 0;
+}
+
+static int idetape_release(struct inode *inode, struct file *filp)
+{
+ struct gendisk *disk = inode->i_bdev->bd_disk;
+ struct ide_tape_obj *tape = ide_tape_g(disk);
+ ide_drive_t *drive = tape->drive;
+
+ drive->usage--;
+
+ ide_tape_put(tape);
+
+ return 0;
+}
+
+static int idetape_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct block_device *bdev = inode->i_bdev;
+ struct ide_tape_obj *tape = ide_tape_g(bdev->bd_disk);
+ ide_drive_t *drive = tape->drive;
+ int err = generic_ide_ioctl(drive, file, bdev, cmd, arg);
+ if (err == -EINVAL)
+ err = idetape_blkdev_ioctl(drive, cmd, arg);
+ return err;
+}
+
+static struct block_device_operations idetape_block_ops = {
+ .owner = THIS_MODULE,
+ .open = idetape_open,
+ .release = idetape_release,
+ .ioctl = idetape_ioctl,
+};
+
+static int idetape_attach (ide_drive_t *drive)
+{
+ idetape_tape_t *tape;
+ struct gendisk *g;
+ int minor;
+
+ if (!strstr("ide-tape", drive->driver_req))
+ goto failed;
+ if (!drive->present)
+ goto failed;
+ if (drive->media != ide_tape)
+ goto failed;
+ if (!idetape_identify_device (drive)) {
+ printk(KERN_ERR "ide-tape: %s: not supported by this version of ide-tape\n", drive->name);
+ goto failed;
+ }
+ if (drive->scsi) {
+ printk("ide-tape: passing drive %s to ide-scsi emulation.\n", drive->name);
+ goto failed;
+ }
+ if (strstr(drive->id->model, "OnStream DI-")) {
+ printk(KERN_WARNING "ide-tape: Use drive %s with ide-scsi emulation and osst.\n", drive->name);
+ printk(KERN_WARNING "ide-tape: OnStream support will be removed soon from ide-tape!\n");
+ }
+ tape = (idetape_tape_t *) kmalloc (sizeof (idetape_tape_t), GFP_KERNEL);
+ if (tape == NULL) {
+ printk(KERN_ERR "ide-tape: %s: Can't allocate a tape structure\n", drive->name);
+ goto failed;
+ }
+
+ g = alloc_disk(1 << PARTN_BITS);
+ if (!g)
+ goto out_free_tape;
+
+ ide_init_disk(g, drive);
+
+ if (ide_register_subdriver(drive, &idetape_driver)) {
+ printk(KERN_ERR "ide-tape: %s: Failed to register the driver with ide.c\n", drive->name);
+ goto out_put_disk;
+ }
+
+ memset(tape, 0, sizeof(*tape));
+
+ kref_init(&tape->kref);
+
+ tape->drive = drive;
+ tape->driver = &idetape_driver;
+ tape->disk = g;
+
+ g->private_data = &tape->driver;
+
+ drive->driver_data = tape;
+
+ down(&idetape_ref_sem);
+ for (minor = 0; idetape_devs[minor]; minor++)
+ ;
+ idetape_devs[minor] = tape;
+ up(&idetape_ref_sem);
+
+ idetape_setup(drive, tape, minor);
+
+ devfs_mk_cdev(MKDEV(HWIF(drive)->major, minor),
+ S_IFCHR | S_IRUGO | S_IWUGO,
+ "%s/mt", drive->devfs_name);
+ devfs_mk_cdev(MKDEV(HWIF(drive)->major, minor + 128),
+ S_IFCHR | S_IRUGO | S_IWUGO,
+ "%s/mtn", drive->devfs_name);
+
+ g->number = devfs_register_tape(drive->devfs_name);
+ g->fops = &idetape_block_ops;
+ ide_register_region(g);
+
+ return 0;
+out_put_disk:
+ put_disk(g);
+out_free_tape:
+ kfree(tape);
+failed:
+ return 1;
+}
+
+MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
+MODULE_LICENSE("GPL");
+
+static void __exit idetape_exit (void)
+{
+ ide_unregister_driver(&idetape_driver);
+ unregister_chrdev(IDETAPE_MAJOR, "ht");
+}
+
+/*
+ * idetape_init will register the driver for each tape.
+ */
+static int idetape_init (void)
+{
+ if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
+ printk(KERN_ERR "ide-tape: Failed to register character device interface\n");
+ return -EBUSY;
+ }
+ ide_register_driver(&idetape_driver);
+ return 0;
+}
+
+module_init(idetape_init);
+module_exit(idetape_exit);
+MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);