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gerrit-public.fairphone.software / kernel / msm-4.9 / 9d094eebd7fd3d3432a974f46490c32cae35edfe / . / drivers / scsi / atari_NCR5380.c
blob: 79e6f045c2a911348a99dfd02a87ab2603b7168c [file] [log] [blame]
/*
* NCR 5380 generic driver routines. These should make it *trivial*
* to implement 5380 SCSI drivers under Linux with a non-trantor
* architecture.
*
* Note that these routines also work with NR53c400 family chips.
*
* Copyright 1993, Drew Eckhardt
* Visionary Computing
* (Unix and Linux consulting and custom programming)
* drew@colorado.edu
* +1 (303) 666-5836
*
* DISTRIBUTION RELEASE 6.
*
* For more information, please consult
*
* NCR 5380 Family
* SCSI Protocol Controller
* Databook
*
* NCR Microelectronics
* 1635 Aeroplaza Drive
* Colorado Springs, CO 80916
* 1+ (719) 578-3400
* 1+ (800) 334-5454
*/
/*
* ++roman: To port the 5380 driver to the Atari, I had to do some changes in
* this file, too:
*
* - Some of the debug statements were incorrect (undefined variables and the
* like). I fixed that.
*
* - In information_transfer(), I think a #ifdef was wrong. Looking at the
* possible DMA transfer size should also happen for REAL_DMA. I added this
* in the #if statement.
*
* - When using real DMA, information_transfer() should return in a DATAOUT
* phase after starting the DMA. It has nothing more to do.
*
* - The interrupt service routine should run main after end of DMA, too (not
* only after RESELECTION interrupts). Additionally, it should _not_ test
* for more interrupts after running main, since a DMA process may have
* been started and interrupts are turned on now. The new int could happen
* inside the execution of NCR5380_intr(), leading to recursive
* calls.
*
* - I've added a function merge_contiguous_buffers() that tries to
* merge scatter-gather buffers that are located at contiguous
* physical addresses and can be processed with the same DMA setup.
* Since most scatter-gather operations work on a page (4K) of
* 4 buffers (1K), in more than 90% of all cases three interrupts and
* DMA setup actions are saved.
*
* - I've deleted all the stuff for AUTOPROBE_IRQ, REAL_DMA_POLL, PSEUDO_DMA
* and USLEEP, because these were messing up readability and will never be
* needed for Atari SCSI.
*
* - I've revised the NCR5380_main() calling scheme (relax the 'main_running'
* stuff), and 'main' is executed in a bottom half if awoken by an
* interrupt.
*
* - The code was quite cluttered up by "#if (NDEBUG & NDEBUG_*) printk..."
* constructs. In my eyes, this made the source rather unreadable, so I
* finally replaced that by the *_PRINTK() macros.
*
*/
/*
* Further development / testing that should be done :
* 1. Test linked command handling code after Eric is ready with
* the high level code.
*/
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_transport_spi.h>
#if (NDEBUG & NDEBUG_LISTS)
#define LIST(x, y) \
do { \
printk("LINE:%d Adding %p to %p\n", \
__LINE__, (void*)(x), (void*)(y)); \
if ((x) == (y)) \
udelay(5); \
} while (0)
#define REMOVE(w, x, y, z) \
do { \
printk("LINE:%d Removing: %p->%p %p->%p \n", \
__LINE__, (void*)(w), (void*)(x), \
(void*)(y), (void*)(z)); \
if ((x) == (y)) \
udelay(5); \
} while (0)
#else
#define LIST(x,y)
#define REMOVE(w,x,y,z)
#endif
#ifndef notyet
#undef LINKED
#endif
/*
* Design
* Issues :
*
* The other Linux SCSI drivers were written when Linux was Intel PC-only,
* and specifically for each board rather than each chip. This makes their
* adaptation to platforms like the Mac (Some of which use NCR5380's)
* more difficult than it has to be.
*
* Also, many of the SCSI drivers were written before the command queuing
* routines were implemented, meaning their implementations of queued
* commands were hacked on rather than designed in from the start.
*
* When I designed the Linux SCSI drivers I figured that
* while having two different SCSI boards in a system might be useful
* for debugging things, two of the same type wouldn't be used.
* Well, I was wrong and a number of users have mailed me about running
* multiple high-performance SCSI boards in a server.
*
* Finally, when I get questions from users, I have no idea what
* revision of my driver they are running.
*
* This driver attempts to address these problems :
* This is a generic 5380 driver. To use it on a different platform,
* one simply writes appropriate system specific macros (ie, data
* transfer - some PC's will use the I/O bus, 68K's must use
* memory mapped) and drops this file in their 'C' wrapper.
*
* As far as command queueing, two queues are maintained for
* each 5380 in the system - commands that haven't been issued yet,
* and commands that are currently executing. This means that an
* unlimited number of commands may be queued, letting
* more commands propagate from the higher driver levels giving higher
* throughput. Note that both I_T_L and I_T_L_Q nexuses are supported,
* allowing multiple commands to propagate all the way to a SCSI-II device
* while a command is already executing.
*
* To solve the multiple-boards-in-the-same-system problem,
* there is a separate instance structure for each instance
* of a 5380 in the system. So, multiple NCR5380 drivers will
* be able to coexist with appropriate changes to the high level
* SCSI code.
*
* A NCR5380_PUBLIC_REVISION macro is provided, with the release
* number (updated for each public release) printed by the
* NCR5380_print_options command, which should be called from the
* wrapper detect function, so that I know what release of the driver
* users are using.
*
* Issues specific to the NCR5380 :
*
* When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
* piece of hardware that requires you to sit in a loop polling for
* the REQ signal as long as you are connected. Some devices are
* brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
* while doing long seek operations.
*
* The workaround for this is to keep track of devices that have
* disconnected. If the device hasn't disconnected, for commands that
* should disconnect, we do something like
*
* while (!REQ is asserted) { sleep for N usecs; poll for M usecs }
*
* Some tweaking of N and M needs to be done. An algorithm based
* on "time to data" would give the best results as long as short time
* to datas (ie, on the same track) were considered, however these
* broken devices are the exception rather than the rule and I'd rather
* spend my time optimizing for the normal case.
*
* Architecture :
*
* At the heart of the design is a coroutine, NCR5380_main,
* which is started when not running by the interrupt handler,
* timer, and queue command function. It attempts to establish
* I_T_L or I_T_L_Q nexuses by removing the commands from the
* issue queue and calling NCR5380_select() if a nexus
* is not established.
*
* Once a nexus is established, the NCR5380_information_transfer()
* phase goes through the various phases as instructed by the target.
* if the target goes into MSG IN and sends a DISCONNECT message,
* the command structure is placed into the per instance disconnected
* queue, and NCR5380_main tries to find more work. If USLEEP
* was defined, and the target is idle for too long, the system
* will try to sleep.
*
* If a command has disconnected, eventually an interrupt will trigger,
* calling NCR5380_intr() which will in turn call NCR5380_reselect
* to reestablish a nexus. This will run main if necessary.
*
* On command termination, the done function will be called as
* appropriate.
*
* SCSI pointers are maintained in the SCp field of SCSI command
* structures, being initialized after the command is connected
* in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
* Note that in violation of the standard, an implicit SAVE POINTERS operation
* is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
*/
/*
* Using this file :
* This file a skeleton Linux SCSI driver for the NCR 5380 series
* of chips. To use it, you write an architecture specific functions
* and macros and include this file in your driver.
*
* These macros control options :
* AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
* for commands that return with a CHECK CONDITION status.
*
* LINKED - if defined, linked commands are supported.
*
* REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
*
* SUPPORT_TAGS - if defined, SCSI-2 tagged queuing is used where possible
*
* These macros MUST be defined :
*
* NCR5380_read(register) - read from the specified register
*
* NCR5380_write(register, value) - write to the specific register
*
* Either real DMA *or* pseudo DMA may be implemented
* REAL functions :
* NCR5380_REAL_DMA should be defined if real DMA is to be used.
* Note that the DMA setup functions should return the number of bytes
* that they were able to program the controller for.
*
* Also note that generic i386/PC versions of these macros are
* available as NCR5380_i386_dma_write_setup,
* NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
*
* NCR5380_dma_write_setup(instance, src, count) - initialize
* NCR5380_dma_read_setup(instance, dst, count) - initialize
* NCR5380_dma_residual(instance); - residual count
*
* PSEUDO functions :
* NCR5380_pwrite(instance, src, count)
* NCR5380_pread(instance, dst, count);
*
* If nothing specific to this implementation needs doing (ie, with external
* hardware), you must also define
*
* NCR5380_queue_command
* NCR5380_reset
* NCR5380_abort
* NCR5380_proc_info
*
* to be the global entry points into the specific driver, ie
* #define NCR5380_queue_command t128_queue_command.
*
* If this is not done, the routines will be defined as static functions
* with the NCR5380* names and the user must provide a globally
* accessible wrapper function.
*
* The generic driver is initialized by calling NCR5380_init(instance),
* after setting the appropriate host specific fields and ID. If the
* driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
* possible) function may be used. Before the specific driver initialization
* code finishes, NCR5380_print_options should be called.
*/
static struct Scsi_Host *first_instance = NULL;
static struct scsi_host_template *the_template = NULL;
/* Macros ease life... :-) */
#define SETUP_HOSTDATA(in) \
struct NCR5380_hostdata *hostdata = \
(struct NCR5380_hostdata *)(in)->hostdata
#define HOSTDATA(in) ((struct NCR5380_hostdata *)(in)->hostdata)
#define NEXT(cmd) ((Scsi_Cmnd *)(cmd)->host_scribble)
#define SET_NEXT(cmd,next) ((cmd)->host_scribble = (void *)(next))
#define NEXTADDR(cmd) ((Scsi_Cmnd **)&(cmd)->host_scribble)
#define HOSTNO instance->host_no
#define H_NO(cmd) (cmd)->device->host->host_no
#ifdef SUPPORT_TAGS
/*
* Functions for handling tagged queuing
* =====================================
*
* ++roman (01/96): Now I've implemented SCSI-2 tagged queuing. Some notes:
*
* Using consecutive numbers for the tags is no good idea in my eyes. There
* could be wrong re-usings if the counter (8 bit!) wraps and some early
* command has been preempted for a long time. My solution: a bitfield for
* remembering used tags.
*
* There's also the problem that each target has a certain queue size, but we
* cannot know it in advance :-( We just see a QUEUE_FULL status being
* returned. So, in this case, the driver internal queue size assumption is
* reduced to the number of active tags if QUEUE_FULL is returned by the
* target. The command is returned to the mid-level, but with status changed
* to BUSY, since --as I've seen-- the mid-level can't handle QUEUE_FULL
* correctly.
*
* We're also not allowed running tagged commands as long as an untagged
* command is active. And REQUEST SENSE commands after a contingent allegiance
* condition _must_ be untagged. To keep track whether an untagged command has
* been issued, the host->busy array is still employed, as it is without
* support for tagged queuing.
*
* One could suspect that there are possible race conditions between
* is_lun_busy(), cmd_get_tag() and cmd_free_tag(). But I think this isn't the
* case: is_lun_busy() and cmd_get_tag() are both called from NCR5380_main(),
* which already guaranteed to be running at most once. It is also the only
* place where tags/LUNs are allocated. So no other allocation can slip
* between that pair, there could only happen a reselection, which can free a
* tag, but that doesn't hurt. Only the sequence in cmd_free_tag() becomes
* important: the tag bit must be cleared before 'nr_allocated' is decreased.
*/
/* -1 for TAG_NONE is not possible with unsigned char cmd->tag */
#undef TAG_NONE
#define TAG_NONE 0xff
typedef struct {
DECLARE_BITMAP(allocated, MAX_TAGS);
int nr_allocated;
int queue_size;
} TAG_ALLOC;
static TAG_ALLOC TagAlloc[8][8]; /* 8 targets and 8 LUNs */
static void __init init_tags(void)
{
int target, lun;
TAG_ALLOC *ta;
if (!setup_use_tagged_queuing)
return;
for (target = 0; target < 8; ++target) {
for (lun = 0; lun < 8; ++lun) {
ta = &TagAlloc[target][lun];
bitmap_zero(ta->allocated, MAX_TAGS);
ta->nr_allocated = 0;
/* At the beginning, assume the maximum queue size we could
* support (MAX_TAGS). This value will be decreased if the target
* returns QUEUE_FULL status.
*/
ta->queue_size = MAX_TAGS;
}
}
}
/* Check if we can issue a command to this LUN: First see if the LUN is marked
* busy by an untagged command. If the command should use tagged queuing, also
* check that there is a free tag and the target's queue won't overflow. This
* function should be called with interrupts disabled to avoid race
* conditions.
*/
static int is_lun_busy(Scsi_Cmnd *cmd, int should_be_tagged)
{
u8 lun = cmd->device->lun;
SETUP_HOSTDATA(cmd->device->host);
if (hostdata->busy[cmd->device->id] & (1 << lun))
return 1;
if (!should_be_tagged ||
!setup_use_tagged_queuing || !cmd->device->tagged_supported)
return 0;
if (TagAlloc[cmd->device->id][lun].nr_allocated >=
TagAlloc[cmd->device->id][lun].queue_size) {
dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %d: no free tags\n",
H_NO(cmd), cmd->device->id, lun);
return 1;
}
return 0;
}
/* Allocate a tag for a command (there are no checks anymore, check_lun_busy()
* must be called before!), or reserve the LUN in 'busy' if the command is
* untagged.
*/
static void cmd_get_tag(Scsi_Cmnd *cmd, int should_be_tagged)
{
u8 lun = cmd->device->lun;
SETUP_HOSTDATA(cmd->device->host);
/* If we or the target don't support tagged queuing, allocate the LUN for
* an untagged command.
*/
if (!should_be_tagged ||
!setup_use_tagged_queuing || !cmd->device->tagged_supported) {
cmd->tag = TAG_NONE;
hostdata->busy[cmd->device->id] |= (1 << lun);
dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %d now allocated by untagged "
"command\n", H_NO(cmd), cmd->device->id, lun);
} else {
TAG_ALLOC *ta = &TagAlloc[cmd->device->id][lun];
cmd->tag = find_first_zero_bit(ta->allocated, MAX_TAGS);
set_bit(cmd->tag, ta->allocated);
ta->nr_allocated++;
dprintk(NDEBUG_TAGS, "scsi%d: using tag %d for target %d lun %d "
"(now %d tags in use)\n",
H_NO(cmd), cmd->tag, cmd->device->id,
lun, ta->nr_allocated);
}
}
/* Mark the tag of command 'cmd' as free, or in case of an untagged command,
* unlock the LUN.
*/
static void cmd_free_tag(Scsi_Cmnd *cmd)
{
u8 lun = cmd->device->lun;
SETUP_HOSTDATA(cmd->device->host);
if (cmd->tag == TAG_NONE) {
hostdata->busy[cmd->device->id] &= ~(1 << lun);
dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %d untagged cmd finished\n",
H_NO(cmd), cmd->device->id, lun);
} else if (cmd->tag >= MAX_TAGS) {
printk(KERN_NOTICE "scsi%d: trying to free bad tag %d!\n",
H_NO(cmd), cmd->tag);
} else {
TAG_ALLOC *ta = &TagAlloc[cmd->device->id][lun];
clear_bit(cmd->tag, ta->allocated);
ta->nr_allocated--;
dprintk(NDEBUG_TAGS, "scsi%d: freed tag %d for target %d lun %d\n",
H_NO(cmd), cmd->tag, cmd->device->id, lun);
}
}
static void free_all_tags(void)
{
int target, lun;
TAG_ALLOC *ta;
if (!setup_use_tagged_queuing)
return;
for (target = 0; target < 8; ++target) {
for (lun = 0; lun < 8; ++lun) {
ta = &TagAlloc[target][lun];
bitmap_zero(ta->allocated, MAX_TAGS);
ta->nr_allocated = 0;
}
}
}
#endif /* SUPPORT_TAGS */
/*
* Function: void merge_contiguous_buffers( Scsi_Cmnd *cmd )
*
* Purpose: Try to merge several scatter-gather requests into one DMA
* transfer. This is possible if the scatter buffers lie on
* physical contiguous addresses.
*
* Parameters: Scsi_Cmnd *cmd
* The command to work on. The first scatter buffer's data are
* assumed to be already transferred into ptr/this_residual.
*/
static void merge_contiguous_buffers(Scsi_Cmnd *cmd)
{
unsigned long endaddr;
#if (NDEBUG & NDEBUG_MERGING)
unsigned long oldlen = cmd->SCp.this_residual;
int cnt = 1;
#endif
for (endaddr = virt_to_phys(cmd->SCp.ptr + cmd->SCp.this_residual - 1) + 1;
cmd->SCp.buffers_residual &&
virt_to_phys(sg_virt(&cmd->SCp.buffer[1])) == endaddr;) {
dprintk(NDEBUG_MERGING, "VTOP(%p) == %08lx -> merging\n",
page_address(sg_page(&cmd->SCp.buffer[1])), endaddr);
#if (NDEBUG & NDEBUG_MERGING)
++cnt;
#endif
++cmd->SCp.buffer;
--cmd->SCp.buffers_residual;
cmd->SCp.this_residual += cmd->SCp.buffer->length;
endaddr += cmd->SCp.buffer->length;
}
#if (NDEBUG & NDEBUG_MERGING)
if (oldlen != cmd->SCp.this_residual)
dprintk(NDEBUG_MERGING, "merged %d buffers from %p, new length %08x\n",
cnt, cmd->SCp.ptr, cmd->SCp.this_residual);
#endif
}
/*
* Function : void initialize_SCp(Scsi_Cmnd *cmd)
*
* Purpose : initialize the saved data pointers for cmd to point to the
* start of the buffer.
*
* Inputs : cmd - Scsi_Cmnd structure to have pointers reset.
*/
static inline void initialize_SCp(Scsi_Cmnd *cmd)
{
/*
* Initialize the Scsi Pointer field so that all of the commands in the
* various queues are valid.
*/
if (scsi_bufflen(cmd)) {
cmd->SCp.buffer = scsi_sglist(cmd);
cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
cmd->SCp.this_residual = cmd->SCp.buffer->length;
/* ++roman: Try to merge some scatter-buffers if they are at
* contiguous physical addresses.
*/
merge_contiguous_buffers(cmd);
} else {
cmd->SCp.buffer = NULL;
cmd->SCp.buffers_residual = 0;
cmd->SCp.ptr = NULL;
cmd->SCp.this_residual = 0;
}
}
#include <linux/delay.h>
#if NDEBUG
static struct {
unsigned char mask;
const char *name;
} signals[] = {
{ SR_DBP, "PARITY"}, { SR_RST, "RST" }, { SR_BSY, "BSY" },
{ SR_REQ, "REQ" }, { SR_MSG, "MSG" }, { SR_CD, "CD" }, { SR_IO, "IO" },
{ SR_SEL, "SEL" }, {0, NULL}
}, basrs[] = {
{BASR_ATN, "ATN"}, {BASR_ACK, "ACK"}, {0, NULL}
}, icrs[] = {
{ICR_ASSERT_RST, "ASSERT RST"},{ICR_ASSERT_ACK, "ASSERT ACK"},
{ICR_ASSERT_BSY, "ASSERT BSY"}, {ICR_ASSERT_SEL, "ASSERT SEL"},
{ICR_ASSERT_ATN, "ASSERT ATN"}, {ICR_ASSERT_DATA, "ASSERT DATA"},
{0, NULL}
}, mrs[] = {
{MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"}, {MR_TARGET, "MODE TARGET"},
{MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"}, {MR_ENABLE_PAR_INTR,
"MODE PARITY INTR"}, {MR_ENABLE_EOP_INTR,"MODE EOP INTR"},
{MR_MONITOR_BSY, "MODE MONITOR BSY"},
{MR_DMA_MODE, "MODE DMA"}, {MR_ARBITRATE, "MODE ARBITRATION"},
{0, NULL}
};
/*
* Function : void NCR5380_print(struct Scsi_Host *instance)
*
* Purpose : print the SCSI bus signals for debugging purposes
*
* Input : instance - which NCR5380
*/
static void NCR5380_print(struct Scsi_Host *instance)
{
unsigned char status, data, basr, mr, icr, i;
unsigned long flags;
local_irq_save(flags);
data = NCR5380_read(CURRENT_SCSI_DATA_REG);
status = NCR5380_read(STATUS_REG);
mr = NCR5380_read(MODE_REG);
icr = NCR5380_read(INITIATOR_COMMAND_REG);
basr = NCR5380_read(BUS_AND_STATUS_REG);
local_irq_restore(flags);
printk("STATUS_REG: %02x ", status);
for (i = 0; signals[i].mask; ++i)
if (status & signals[i].mask)
printk(",%s", signals[i].name);
printk("\nBASR: %02x ", basr);
for (i = 0; basrs[i].mask; ++i)
if (basr & basrs[i].mask)
printk(",%s", basrs[i].name);
printk("\nICR: %02x ", icr);
for (i = 0; icrs[i].mask; ++i)
if (icr & icrs[i].mask)
printk(",%s", icrs[i].name);
printk("\nMODE: %02x ", mr);
for (i = 0; mrs[i].mask; ++i)
if (mr & mrs[i].mask)
printk(",%s", mrs[i].name);
printk("\n");
}
static struct {
unsigned char value;
const char *name;
} phases[] = {
{PHASE_DATAOUT, "DATAOUT"}, {PHASE_DATAIN, "DATAIN"}, {PHASE_CMDOUT, "CMDOUT"},
{PHASE_STATIN, "STATIN"}, {PHASE_MSGOUT, "MSGOUT"}, {PHASE_MSGIN, "MSGIN"},
{PHASE_UNKNOWN, "UNKNOWN"}
};
/*
* Function : void NCR5380_print_phase(struct Scsi_Host *instance)
*
* Purpose : print the current SCSI phase for debugging purposes
*
* Input : instance - which NCR5380
*/
static void NCR5380_print_phase(struct Scsi_Host *instance)
{
unsigned char status;
int i;
status = NCR5380_read(STATUS_REG);
if (!(status & SR_REQ))
printk(KERN_DEBUG "scsi%d: REQ not asserted, phase unknown.\n", HOSTNO);
else {
for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
(phases[i].value != (status & PHASE_MASK)); ++i)
;
printk(KERN_DEBUG "scsi%d: phase %s\n", HOSTNO, phases[i].name);
}
}
#endif
/*
* ++roman: New scheme of calling NCR5380_main()
*
* If we're not in an interrupt, we can call our main directly, it cannot be
* already running. Else, we queue it on a task queue, if not 'main_running'
* tells us that a lower level is already executing it. This way,
* 'main_running' needs not be protected in a special way.
*
* queue_main() is a utility function for putting our main onto the task
* queue, if main_running is false. It should be called only from a
* interrupt or bottom half.
*/
#include <linux/gfp.h>
#include <linux/workqueue.h>
#include <linux/interrupt.h>
static volatile int main_running;
static DECLARE_WORK(NCR5380_tqueue, NCR5380_main);
static inline void queue_main(void)
{
if (!main_running) {
/* If in interrupt and NCR5380_main() not already running,
queue it on the 'immediate' task queue, to be processed
immediately after the current interrupt processing has
finished. */
schedule_work(&NCR5380_tqueue);
}
/* else: nothing to do: the running NCR5380_main() will pick up
any newly queued command. */
}
static inline void NCR5380_all_init(void)
{
static int done = 0;
if (!done) {
dprintk(NDEBUG_INIT, "scsi : NCR5380_all_init()\n");
done = 1;
}
}
/*
* Function : void NCR58380_print_options (struct Scsi_Host *instance)
*
* Purpose : called by probe code indicating the NCR5380 driver
* options that were selected.
*
* Inputs : instance, pointer to this instance. Unused.
*/
static void __init NCR5380_print_options(struct Scsi_Host *instance)
{
printk(" generic options"
#ifdef AUTOSENSE
" AUTOSENSE"
#endif
#ifdef REAL_DMA
" REAL DMA"
#endif
#ifdef PARITY
" PARITY"
#endif
#ifdef SUPPORT_TAGS
" SCSI-2 TAGGED QUEUING"
#endif
);
printk(" generic release=%d", NCR5380_PUBLIC_RELEASE);
}
/*
* Function : void NCR5380_print_status (struct Scsi_Host *instance)
*
* Purpose : print commands in the various queues, called from
* NCR5380_abort and NCR5380_debug to aid debugging.
*
* Inputs : instance, pointer to this instance.
*/
static void lprint_Scsi_Cmnd(Scsi_Cmnd *cmd)
{
int i, s;
unsigned char *command;
printk("scsi%d: destination target %d, lun %llu\n",
H_NO(cmd), cmd->device->id, cmd->device->lun);
printk(KERN_CONT " command = ");
command = cmd->cmnd;
printk(KERN_CONT "%2d (0x%02x)", command[0], command[0]);
for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
printk(KERN_CONT " %02x", command[i]);
printk("\n");
}
static void NCR5380_print_status(struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata;
Scsi_Cmnd *ptr;
unsigned long flags;
NCR5380_dprint(NDEBUG_ANY, instance);
NCR5380_dprint_phase(NDEBUG_ANY, instance);
hostdata = (struct NCR5380_hostdata *)instance->hostdata;
printk("\nNCR5380 core release=%d.\n", NCR5380_PUBLIC_RELEASE);
local_irq_save(flags);
printk("NCR5380: coroutine is%s running.\n",
main_running ? "" : "n't");
if (!hostdata->connected)
printk("scsi%d: no currently connected command\n", HOSTNO);
else
lprint_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected);
printk("scsi%d: issue_queue\n", HOSTNO);
for (ptr = (Scsi_Cmnd *)hostdata->issue_queue; ptr; ptr = NEXT(ptr))
lprint_Scsi_Cmnd(ptr);
printk("scsi%d: disconnected_queue\n", HOSTNO);
for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr;
ptr = NEXT(ptr))
lprint_Scsi_Cmnd(ptr);
local_irq_restore(flags);
printk("\n");
}
static void show_Scsi_Cmnd(Scsi_Cmnd *cmd, struct seq_file *m)
{
int i, s;
unsigned char *command;
seq_printf(m, "scsi%d: destination target %d, lun %llu\n",
H_NO(cmd), cmd->device->id, cmd->device->lun);
seq_printf(m, " command = ");
command = cmd->cmnd;
seq_printf(m, "%2d (0x%02x)", command[0], command[0]);
for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
seq_printf(m, " %02x", command[i]);
seq_printf(m, "\n");
}
static int NCR5380_show_info(struct seq_file *m, struct Scsi_Host *instance)
{
struct NCR5380_hostdata *hostdata;
Scsi_Cmnd *ptr;
unsigned long flags;
hostdata = (struct NCR5380_hostdata *)instance->hostdata;
seq_printf(m, "NCR5380 core release=%d.\n", NCR5380_PUBLIC_RELEASE);
local_irq_save(flags);
seq_printf(m, "NCR5380: coroutine is%s running.\n",
main_running ? "" : "n't");
if (!hostdata->connected)
seq_printf(m, "scsi%d: no currently connected command\n", HOSTNO);
else
show_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected, m);
seq_printf(m, "scsi%d: issue_queue\n", HOSTNO);
for (ptr = (Scsi_Cmnd *)hostdata->issue_queue; ptr; ptr = NEXT(ptr))
show_Scsi_Cmnd(ptr, m);
seq_printf(m, "scsi%d: disconnected_queue\n", HOSTNO);
for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr;
ptr = NEXT(ptr))
show_Scsi_Cmnd(ptr, m);
local_irq_restore(flags);
return 0;
}
/*
* Function : void NCR5380_init (struct Scsi_Host *instance)
*
* Purpose : initializes *instance and corresponding 5380 chip.
*
* Inputs : instance - instantiation of the 5380 driver.
*
* Notes : I assume that the host, hostno, and id bits have been
* set correctly. I don't care about the irq and other fields.
*
*/
static int __init NCR5380_init(struct Scsi_Host *instance, int flags)
{
int i;
SETUP_HOSTDATA(instance);
NCR5380_all_init();
hostdata->aborted = 0;
hostdata->id_mask = 1 << instance->this_id;
hostdata->id_higher_mask = 0;
for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
if (i > hostdata->id_mask)
hostdata->id_higher_mask |= i;
for (i = 0; i < 8; ++i)
hostdata->busy[i] = 0;
#ifdef SUPPORT_TAGS
init_tags();
#endif
#if defined (REAL_DMA)
hostdata->dma_len = 0;
#endif
hostdata->targets_present = 0;
hostdata->connected = NULL;
hostdata->issue_queue = NULL;
hostdata->disconnected_queue = NULL;
hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT;
if (!the_template) {
the_template = instance->hostt;
first_instance = instance;
}
#ifndef AUTOSENSE
if ((instance->cmd_per_lun > 1) || (instance->can_queue > 1))
printk("scsi%d: WARNING : support for multiple outstanding commands enabled\n"
" without AUTOSENSE option, contingent allegiance conditions may\n"
" be incorrectly cleared.\n", HOSTNO);
#endif /* def AUTOSENSE */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(TARGET_COMMAND_REG, 0);
NCR5380_write(SELECT_ENABLE_REG, 0);
return 0;
}
static void NCR5380_exit(struct Scsi_Host *instance)
{
/* Empty, as we didn't schedule any delayed work */
}
/*
* Function : int NCR5380_queue_command (Scsi_Cmnd *cmd,
* void (*done)(Scsi_Cmnd *))
*
* Purpose : enqueues a SCSI command
*
* Inputs : cmd - SCSI command, done - function called on completion, with
* a pointer to the command descriptor.
*
* Returns : 0
*
* Side effects :
* cmd is added to the per instance issue_queue, with minor
* twiddling done to the host specific fields of cmd. If the
* main coroutine is not running, it is restarted.
*
*/
static int NCR5380_queue_command_lck(Scsi_Cmnd *cmd, void (*done)(Scsi_Cmnd *))
{
SETUP_HOSTDATA(cmd->device->host);
Scsi_Cmnd *tmp;
unsigned long flags;
#if (NDEBUG & NDEBUG_NO_WRITE)
switch (cmd->cmnd[0]) {
case WRITE_6:
case WRITE_10:
printk(KERN_NOTICE "scsi%d: WRITE attempted with NO_WRITE debugging flag set\n",
H_NO(cmd));
cmd->result = (DID_ERROR << 16);
done(cmd);
return 0;
}
#endif /* (NDEBUG & NDEBUG_NO_WRITE) */
#ifdef NCR5380_STATS
# if 0
if (!hostdata->connected && !hostdata->issue_queue &&
!hostdata->disconnected_queue) {
hostdata->timebase = jiffies;
}
# endif
# ifdef NCR5380_STAT_LIMIT
if (scsi_bufflen(cmd) > NCR5380_STAT_LIMIT)
# endif
switch (cmd->cmnd[0]) {
case WRITE:
case WRITE_6:
case WRITE_10:
hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase);
hostdata->bytes_write[cmd->device->id] += scsi_bufflen(cmd);
hostdata->pendingw++;
break;
case READ:
case READ_6:
case READ_10:
hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase);
hostdata->bytes_read[cmd->device->id] += scsi_bufflen(cmd);
hostdata->pendingr++;
break;
}
#endif
/*
* We use the host_scribble field as a pointer to the next command
* in a queue
*/
SET_NEXT(cmd, NULL);
cmd->scsi_done = done;
cmd->result = 0;
/*
* Insert the cmd into the issue queue. Note that REQUEST SENSE
* commands are added to the head of the queue since any command will
* clear the contingent allegiance condition that exists and the
* sense data is only guaranteed to be valid while the condition exists.
*/
local_irq_save(flags);
/* ++guenther: now that the issue queue is being set up, we can lock ST-DMA.
* Otherwise a running NCR5380_main may steal the lock.
* Lock before actually inserting due to fairness reasons explained in
* atari_scsi.c. If we insert first, then it's impossible for this driver
* to release the lock.
* Stop timer for this command while waiting for the lock, or timeouts
* may happen (and they really do), and it's no good if the command doesn't
* appear in any of the queues.
* ++roman: Just disabling the NCR interrupt isn't sufficient here,
* because also a timer int can trigger an abort or reset, which would
* alter queues and touch the lock.
*/
if (!IS_A_TT()) {
/* perhaps stop command timer here */
falcon_get_lock();
/* perhaps restart command timer here */
}
if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
LIST(cmd, hostdata->issue_queue);
SET_NEXT(cmd, hostdata->issue_queue);
hostdata->issue_queue = cmd;
} else {
for (tmp = (Scsi_Cmnd *)hostdata->issue_queue;
NEXT(tmp); tmp = NEXT(tmp))
;
LIST(cmd, tmp);
SET_NEXT(tmp, cmd);
}
local_irq_restore(flags);
dprintk(NDEBUG_QUEUES, "scsi%d: command added to %s of queue\n", H_NO(cmd),
(cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
/* If queue_command() is called from an interrupt (real one or bottom
* half), we let queue_main() do the job of taking care about main. If it
* is already running, this is a no-op, else main will be queued.
*
* If we're not in an interrupt, we can call NCR5380_main()
* unconditionally, because it cannot be already running.
*/
if (in_interrupt() || ((flags >> 8) & 7) >= 6)
queue_main();
else
NCR5380_main(NULL);
return 0;
}
static DEF_SCSI_QCMD(NCR5380_queue_command)
/*
* Function : NCR5380_main (void)
*
* Purpose : NCR5380_main is a coroutine that runs as long as more work can
* be done on the NCR5380 host adapters in a system. Both
* NCR5380_queue_command() and NCR5380_intr() will try to start it
* in case it is not running.
*
* NOTE : NCR5380_main exits with interrupts *disabled*, the caller should
* reenable them. This prevents reentrancy and kernel stack overflow.
*/
static void NCR5380_main(struct work_struct *work)
{
Scsi_Cmnd *tmp, *prev;
struct Scsi_Host *instance = first_instance;
struct NCR5380_hostdata *hostdata = HOSTDATA(instance);
int done;
unsigned long flags;
/*
* We run (with interrupts disabled) until we're sure that none of
* the host adapters have anything that can be done, at which point
* we set main_running to 0 and exit.
*
* Interrupts are enabled before doing various other internal
* instructions, after we've decided that we need to run through
* the loop again.
*
* this should prevent any race conditions.
*
* ++roman: Just disabling the NCR interrupt isn't sufficient here,
* because also a timer int can trigger an abort or reset, which can
* alter queues and touch the Falcon lock.
*/
/* Tell int handlers main() is now already executing. Note that
no races are possible here. If an int comes in before
'main_running' is set here, and queues/executes main via the
task queue, it doesn't do any harm, just this instance of main
won't find any work left to do. */
if (main_running)
return;
main_running = 1;
local_save_flags(flags);
do {
local_irq_disable(); /* Freeze request queues */
done = 1;
if (!hostdata->connected) {
dprintk(NDEBUG_MAIN, "scsi%d: not connected\n", HOSTNO);
/*
* Search through the issue_queue for a command destined
* for a target that's not busy.
*/
#if (NDEBUG & NDEBUG_LISTS)
for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, prev = NULL;
tmp && (tmp != prev); prev = tmp, tmp = NEXT(tmp))
;
/*printk("%p ", tmp);*/
if ((tmp == prev) && tmp)
printk(" LOOP\n");
/* else printk("\n"); */
#endif
for (tmp = (Scsi_Cmnd *) hostdata->issue_queue,
prev = NULL; tmp; prev = tmp, tmp = NEXT(tmp)) {
u8 lun = tmp->device->lun;
#if (NDEBUG & NDEBUG_LISTS)
if (prev != tmp)
printk("MAIN tmp=%p target=%d busy=%d lun=%llu\n",
tmp, tmp->device->id, hostdata->busy[tmp->device->id],
lun);
#endif
/* When we find one, remove it from the issue queue. */
/* ++guenther: possible race with Falcon locking */
if (
#ifdef SUPPORT_TAGS
!is_lun_busy( tmp, tmp->cmnd[0] != REQUEST_SENSE)
#else
!(hostdata->busy[tmp->device->id] & (1 << lun))
#endif
) {
/* ++guenther: just to be sure, this must be atomic */
local_irq_disable();
if (prev) {
REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
SET_NEXT(prev, NEXT(tmp));
} else {
REMOVE(-1, hostdata->issue_queue, tmp, NEXT(tmp));
hostdata->issue_queue = NEXT(tmp);
}
SET_NEXT(tmp, NULL);
falcon_dont_release++;
/* reenable interrupts after finding one */
local_irq_restore(flags);
/*
* Attempt to establish an I_T_L nexus here.
* On success, instance->hostdata->connected is set.
* On failure, we must add the command back to the
* issue queue so we can keep trying.
*/
dprintk(NDEBUG_MAIN, "scsi%d: main(): command for target %d "
"lun %d removed from issue_queue\n",
HOSTNO, tmp->device->id, lun);
/*
* REQUEST SENSE commands are issued without tagged
* queueing, even on SCSI-II devices because the
* contingent allegiance condition exists for the
* entire unit.
*/
/* ++roman: ...and the standard also requires that
* REQUEST SENSE command are untagged.
*/
#ifdef SUPPORT_TAGS
cmd_get_tag(tmp, tmp->cmnd[0] != REQUEST_SENSE);
#endif
if (!NCR5380_select(instance, tmp,
(tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE :
TAG_NEXT)) {
falcon_dont_release--;
/* release if target did not response! */
falcon_release_lock_if_possible(hostdata);
break;
} else {
local_irq_disable();
LIST(tmp, hostdata->issue_queue);
SET_NEXT(tmp, hostdata->issue_queue);
hostdata->issue_queue = tmp;
#ifdef SUPPORT_TAGS
cmd_free_tag(tmp);
#endif
falcon_dont_release--;
local_irq_restore(flags);
dprintk(NDEBUG_MAIN, "scsi%d: main(): select() failed, "
"returned to issue_queue\n", HOSTNO);
if (hostdata->connected)
break;
}
} /* if target/lun/target queue is not busy */
} /* for issue_queue */
} /* if (!hostdata->connected) */
if (hostdata->connected
#ifdef REAL_DMA
&& !hostdata->dma_len
#endif
) {
local_irq_restore(flags);
dprintk(NDEBUG_MAIN, "scsi%d: main: performing information transfer\n",
HOSTNO);
NCR5380_information_transfer(instance);
dprintk(NDEBUG_MAIN, "scsi%d: main: done set false\n", HOSTNO);
done = 0;
}
} while (!done);
/* Better allow ints _after_ 'main_running' has been cleared, else
an interrupt could believe we'll pick up the work it left for
us, but we won't see it anymore here... */
main_running = 0;
local_irq_restore(flags);
}
#ifdef REAL_DMA
/*
* Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
*
* Purpose : Called by interrupt handler when DMA finishes or a phase
* mismatch occurs (which would finish the DMA transfer).
*
* Inputs : instance - this instance of the NCR5380.
*
*/
static void NCR5380_dma_complete(struct Scsi_Host *instance)
{
SETUP_HOSTDATA(instance);
int transfered, saved_data = 0, overrun = 0, cnt, toPIO;
unsigned char **data, p;
volatile int *count;
if (!hostdata->connected) {
printk(KERN_WARNING "scsi%d: received end of DMA interrupt with "
"no connected cmd\n", HOSTNO);
return;
}
if (atari_read_overruns) {
p = hostdata->connected->SCp.phase;
if (p & SR_IO) {
udelay(10);
if ((NCR5380_read(BUS_AND_STATUS_REG) &
(BASR_PHASE_MATCH|BASR_ACK)) ==
(BASR_PHASE_MATCH|BASR_ACK)) {
saved_data = NCR5380_read(INPUT_DATA_REG);
overrun = 1;
dprintk(NDEBUG_DMA, "scsi%d: read overrun handled\n", HOSTNO);
}
}
}
dprintk(NDEBUG_DMA, "scsi%d: real DMA transfer complete, basr 0x%X, sr 0x%X\n",
HOSTNO, NCR5380_read(BUS_AND_STATUS_REG),
NCR5380_read(STATUS_REG));
(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
transfered = hostdata->dma_len - NCR5380_dma_residual(instance);
hostdata->dma_len = 0;
data = (unsigned char **)&hostdata->connected->SCp.ptr;
count = &hostdata->connected->SCp.this_residual;
*data += transfered;
*count -= transfered;
if (atari_read_overruns) {
if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
cnt = toPIO = atari_read_overruns;
if (overrun) {
dprintk(NDEBUG_DMA, "Got an input overrun, using saved byte\n");
*(*data)++ = saved_data;
(*count)--;
cnt--;
toPIO--;
}
dprintk(NDEBUG_DMA, "Doing %d-byte PIO to 0x%08lx\n", cnt, (long)*data);
NCR5380_transfer_pio(instance, &p, &cnt, data);
*count -= toPIO - cnt;
}
}
}
#endif /* REAL_DMA */
/*
* Function : void NCR5380_intr (int irq)
*
* Purpose : handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
* from the disconnected queue, and restarting NCR5380_main()
* as required.
*
* Inputs : int irq, irq that caused this interrupt.
*
*/
static irqreturn_t NCR5380_intr(int irq, void *dev_id)
{
struct Scsi_Host *instance = first_instance;
int done = 1, handled = 0;
unsigned char basr;
dprintk(NDEBUG_INTR, "scsi%d: NCR5380 irq triggered\n", HOSTNO);
/* Look for pending interrupts */
basr = NCR5380_read(BUS_AND_STATUS_REG);
dprintk(NDEBUG_INTR, "scsi%d: BASR=%02x\n", HOSTNO, basr);
/* dispatch to appropriate routine if found and done=0 */
if (basr & BASR_IRQ) {
NCR5380_dprint(NDEBUG_INTR, instance);
if ((NCR5380_read(STATUS_REG) & (SR_SEL|SR_IO)) == (SR_SEL|SR_IO)) {
done = 0;
ENABLE_IRQ();
dprintk(NDEBUG_INTR, "scsi%d: SEL interrupt\n", HOSTNO);
NCR5380_reselect(instance);
(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
} else if (basr & BASR_PARITY_ERROR) {
dprintk(NDEBUG_INTR, "scsi%d: PARITY interrupt\n", HOSTNO);
(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
} else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
dprintk(NDEBUG_INTR, "scsi%d: RESET interrupt\n", HOSTNO);
(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
} else {
/*
* The rest of the interrupt conditions can occur only during a
* DMA transfer
*/
#if defined(REAL_DMA)
/*
* We should only get PHASE MISMATCH and EOP interrupts if we have
* DMA enabled, so do a sanity check based on the current setting
* of the MODE register.
*/
if ((NCR5380_read(MODE_REG) & MR_DMA_MODE) &&
((basr & BASR_END_DMA_TRANSFER) ||
!(basr & BASR_PHASE_MATCH))) {
dprintk(NDEBUG_INTR, "scsi%d: PHASE MISM or EOP interrupt\n", HOSTNO);
NCR5380_dma_complete( instance );
done = 0;
ENABLE_IRQ();
} else
#endif /* REAL_DMA */
{
/* MS: Ignore unknown phase mismatch interrupts (caused by EOP interrupt) */
if (basr & BASR_PHASE_MATCH)
printk(KERN_NOTICE "scsi%d: unknown interrupt, "
"BASR 0x%x, MR 0x%x, SR 0x%x\n",
HOSTNO, basr, NCR5380_read(MODE_REG),
NCR5380_read(STATUS_REG));
(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
}
} /* if !(SELECTION || PARITY) */
handled = 1;
} /* BASR & IRQ */ else {
printk(KERN_NOTICE "scsi%d: interrupt without IRQ bit set in BASR, "
"BASR 0x%X, MR 0x%X, SR 0x%x\n", HOSTNO, basr,
NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG));
(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
}
if (!done) {
dprintk(NDEBUG_INTR, "scsi%d: in int routine, calling main\n", HOSTNO);
/* Put a call to NCR5380_main() on the queue... */
queue_main();
}
return IRQ_RETVAL(handled);
}
#ifdef NCR5380_STATS
static void collect_stats(struct NCR5380_hostdata* hostdata, Scsi_Cmnd *cmd)
{
# ifdef NCR5380_STAT_LIMIT
if (scsi_bufflen(cmd) > NCR5380_STAT_LIMIT)
# endif
switch (cmd->cmnd[0]) {
case WRITE:
case WRITE_6:
case WRITE_10:
hostdata->time_write[cmd->device->id] += (jiffies - hostdata->timebase);
/*hostdata->bytes_write[cmd->device->id] += scsi_bufflen(cmd);*/
hostdata->pendingw--;
break;
case READ:
case READ_6:
case READ_10:
hostdata->time_read[cmd->device->id] += (jiffies - hostdata->timebase);
/*hostdata->bytes_read[cmd->device->id] += scsi_bufflen(cmd);*/
hostdata->pendingr--;
break;
}
}
#endif
/*
* Function : int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd,
* int tag);
*
* Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
* including ARBITRATION, SELECTION, and initial message out for
* IDENTIFY and queue messages.
*
* Inputs : instance - instantiation of the 5380 driver on which this
* target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for
* new tag, TAG_NONE for untagged queueing, otherwise set to the tag for
* the command that is presently connected.
*
* Returns : -1 if selection could not execute for some reason,
* 0 if selection succeeded or failed because the target
* did not respond.
*
* Side effects :
* If bus busy, arbitration failed, etc, NCR5380_select() will exit
* with registers as they should have been on entry - ie
* SELECT_ENABLE will be set appropriately, the NCR5380
* will cease to drive any SCSI bus signals.
*
* If successful : I_T_L or I_T_L_Q nexus will be established,
* instance->connected will be set to cmd.
* SELECT interrupt will be disabled.
*
* If failed (no target) : cmd->scsi_done() will be called, and the
* cmd->result host byte set to DID_BAD_TARGET.
*/
static int NCR5380_select(struct Scsi_Host *instance, Scsi_Cmnd *cmd, int tag)
{
SETUP_HOSTDATA(instance);
unsigned char tmp[3], phase;
unsigned char *data;
int len;
unsigned long timeout;
unsigned long flags;
hostdata->restart_select = 0;
NCR5380_dprint(NDEBUG_ARBITRATION, instance);
dprintk(NDEBUG_ARBITRATION, "scsi%d: starting arbitration, id = %d\n", HOSTNO,
instance->this_id);
/*
* Set the phase bits to 0, otherwise the NCR5380 won't drive the
* data bus during SELECTION.
*/
local_irq_save(flags);
if (hostdata->connected) {
local_irq_restore(flags);
return -1;
}
NCR5380_write(TARGET_COMMAND_REG, 0);
/*
* Start arbitration.
*/
NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
NCR5380_write(MODE_REG, MR_ARBITRATE);
local_irq_restore(flags);
/* Wait for arbitration logic to complete */
#if defined(NCR_TIMEOUT)
{
unsigned long timeout = jiffies + 2*NCR_TIMEOUT;
while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
time_before(jiffies, timeout) && !hostdata->connected)
;
if (time_after_eq(jiffies, timeout)) {
printk("scsi : arbitration timeout at %d\n", __LINE__);
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
return -1;
}
}
#else /* NCR_TIMEOUT */
while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
!hostdata->connected)
;
#endif
dprintk(NDEBUG_ARBITRATION, "scsi%d: arbitration complete\n", HOSTNO);
if (hostdata->connected) {
NCR5380_write(MODE_REG, MR_BASE);
return -1;
}
/*
* The arbitration delay is 2.2us, but this is a minimum and there is
* no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
* the integral nature of udelay().
*
*/
udelay(3);
/* Check for lost arbitration */
if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
(NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
hostdata->connected) {
NCR5380_write(MODE_REG, MR_BASE);
dprintk(NDEBUG_ARBITRATION, "scsi%d: lost arbitration, deasserting MR_ARBITRATE\n",
HOSTNO);
return -1;
}
/* after/during arbitration, BSY should be asserted.
IBM DPES-31080 Version S31Q works now */
/* Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman) */
NCR5380_write(INITIATOR_COMMAND_REG,
ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
hostdata->connected) {
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
dprintk(NDEBUG_ARBITRATION, "scsi%d: lost arbitration, deasserting ICR_ASSERT_SEL\n",
HOSTNO);
return -1;
}
/*
* Again, bus clear + bus settle time is 1.2us, however, this is
* a minimum so we'll udelay ceil(1.2)
*/
#ifdef CONFIG_ATARI_SCSI_TOSHIBA_DELAY
/* ++roman: But some targets (see above :-) seem to need a bit more... */
udelay(15);
#else
udelay(2);
#endif
if (hostdata->connected) {
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
return -1;
}
dprintk(NDEBUG_ARBITRATION, "scsi%d: won arbitration\n", HOSTNO);
/*
* Now that we have won arbitration, start Selection process, asserting
* the host and target ID's on the SCSI bus.
*/
NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << cmd->device->id)));
/*
* Raise ATN while SEL is true before BSY goes false from arbitration,
* since this is the only way to guarantee that we'll get a MESSAGE OUT
* phase immediately after selection.
*/
NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY |
ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL ));
NCR5380_write(MODE_REG, MR_BASE);
/*
* Reselect interrupts must be turned off prior to the dropping of BSY,
* otherwise we will trigger an interrupt.
*/
if (hostdata->connected) {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
return -1;
}
NCR5380_write(SELECT_ENABLE_REG, 0);
/*
* The initiator shall then wait at least two deskew delays and release
* the BSY signal.
*/
udelay(1); /* wingel -- wait two bus deskew delay >2*45ns */
/* Reset BSY */
NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA |
ICR_ASSERT_ATN | ICR_ASSERT_SEL));
/*
* Something weird happens when we cease to drive BSY - looks
* like the board/chip is letting us do another read before the
* appropriate propagation delay has expired, and we're confusing
* a BSY signal from ourselves as the target's response to SELECTION.
*
* A small delay (the 'C++' frontend breaks the pipeline with an
* unnecessary jump, making it work on my 386-33/Trantor T128, the
* tighter 'C' code breaks and requires this) solves the problem -
* the 1 us delay is arbitrary, and only used because this delay will
* be the same on other platforms and since it works here, it should
* work there.
*
* wingel suggests that this could be due to failing to wait
* one deskew delay.
*/
udelay(1);
dprintk(NDEBUG_SELECTION, "scsi%d: selecting target %d\n", HOSTNO, cmd->device->id);
/*
* The SCSI specification calls for a 250 ms timeout for the actual
* selection.
*/
timeout = jiffies + 25;
/*
* XXX very interesting - we're seeing a bounce where the BSY we
* asserted is being reflected / still asserted (propagation delay?)
* and it's detecting as true. Sigh.
*/
#if 0
/* ++roman: If a target conformed to the SCSI standard, it wouldn't assert
* IO while SEL is true. But again, there are some disks out the in the
* world that do that nevertheless. (Somebody claimed that this announces
* reselection capability of the target.) So we better skip that test and
* only wait for BSY... (Famous german words: Der Klügere gibt nach :-)
*/
while (time_before(jiffies, timeout) &&
!(NCR5380_read(STATUS_REG) & (SR_BSY | SR_IO)))
;
if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
NCR5380_reselect(instance);
printk(KERN_ERR "scsi%d: reselection after won arbitration?\n",
HOSTNO);
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
return -1;
}
#else
while (time_before(jiffies, timeout) && !(NCR5380_read(STATUS_REG) & SR_BSY))
;
#endif
/*
* No less than two deskew delays after the initiator detects the
* BSY signal is true, it shall release the SEL signal and may
* change the DATA BUS. -wingel
*/
udelay(1);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
if (hostdata->targets_present & (1 << cmd->device->id)) {
printk(KERN_ERR "scsi%d: weirdness\n", HOSTNO);
if (hostdata->restart_select)
printk(KERN_NOTICE "\trestart select\n");
NCR5380_dprint(NDEBUG_ANY, instance);
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
return -1;
}
cmd->result = DID_BAD_TARGET << 16;
#ifdef NCR5380_STATS
collect_stats(hostdata, cmd);
#endif
#ifdef SUPPORT_TAGS
cmd_free_tag(cmd);
#endif
cmd->scsi_done(cmd);
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
dprintk(NDEBUG_SELECTION, "scsi%d: target did not respond within 250ms\n", HOSTNO);
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
return 0;
}
hostdata->targets_present |= (1 << cmd->device->id);
/*
* Since we followed the SCSI spec, and raised ATN while SEL
* was true but before BSY was false during selection, the information
* transfer phase should be a MESSAGE OUT phase so that we can send the
* IDENTIFY message.
*
* If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
* message (2 bytes) with a tag ID that we increment with every command
* until it wraps back to 0.
*
* XXX - it turns out that there are some broken SCSI-II devices,
* which claim to support tagged queuing but fail when more than
* some number of commands are issued at once.
*/
/* Wait for start of REQ/ACK handshake */
while (!(NCR5380_read(STATUS_REG) & SR_REQ))
;
dprintk(NDEBUG_SELECTION, "scsi%d: target %d selected, going into MESSAGE OUT phase.\n",
HOSTNO, cmd->device->id);
tmp[0] = IDENTIFY(1, cmd->device->lun);
#ifdef SUPPORT_TAGS
if (cmd->tag != TAG_NONE) {
tmp[1] = hostdata->last_message = SIMPLE_QUEUE_TAG;
tmp[2] = cmd->tag;
len = 3;
} else
len = 1;
#else
len = 1;
cmd->tag = 0;
#endif /* SUPPORT_TAGS */
/* Send message(s) */
data = tmp;
phase = PHASE_MSGOUT;
NCR5380_transfer_pio(instance, &phase, &len, &data);
dprintk(NDEBUG_SELECTION, "scsi%d: nexus established.\n", HOSTNO);
/* XXX need to handle errors here */
hostdata->connected = cmd;
#ifndef SUPPORT_TAGS
hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
#endif
initialize_SCp(cmd);
return 0;
}
/*
* Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
* unsigned char *phase, int *count, unsigned char **data)
*
* Purpose : transfers data in given phase using polled I/O
*
* Inputs : instance - instance of driver, *phase - pointer to
* what phase is expected, *count - pointer to number of
* bytes to transfer, **data - pointer to data pointer.
*
* Returns : -1 when different phase is entered without transferring
* maximum number of bytes, 0 if all bytes are transferred or exit
* is in same phase.
*
* Also, *phase, *count, *data are modified in place.
*
* XXX Note : handling for bus free may be useful.
*/
/*
* Note : this code is not as quick as it could be, however it
* IS 100% reliable, and for the actual data transfer where speed
* counts, we will always do a pseudo DMA or DMA transfer.
*/
static int NCR5380_transfer_pio(struct Scsi_Host *instance,
unsigned char *phase, int *count,
unsigned char **data)
{
register unsigned char p = *phase, tmp;
register int c = *count;
register unsigned char *d = *data;
/*
* The NCR5380 chip will only drive the SCSI bus when the
* phase specified in the appropriate bits of the TARGET COMMAND
* REGISTER match the STATUS REGISTER
*/
NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
do {
/*
* Wait for assertion of REQ, after which the phase bits will be
* valid
*/
while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
;
dprintk(NDEBUG_HANDSHAKE, "scsi%d: REQ detected\n", HOSTNO);
/* Check for phase mismatch */
if ((tmp & PHASE_MASK) != p) {
dprintk(NDEBUG_PIO, "scsi%d: phase mismatch\n", HOSTNO);
NCR5380_dprint_phase(NDEBUG_PIO, instance);
break;
}
/* Do actual transfer from SCSI bus to / from memory */
if (!(p & SR_IO))
NCR5380_write(OUTPUT_DATA_REG, *d);
else
*d = NCR5380_read(CURRENT_SCSI_DATA_REG);
++d;
/*
* The SCSI standard suggests that in MSGOUT phase, the initiator
* should drop ATN on the last byte of the message phase
* after REQ has been asserted for the handshake but before
* the initiator raises ACK.
*/
if (!(p & SR_IO)) {
if (!((p & SR_MSG) && c > 1)) {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
NCR5380_dprint(NDEBUG_PIO, instance);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
ICR_ASSERT_DATA | ICR_ASSERT_ACK);
} else {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
ICR_ASSERT_DATA | ICR_ASSERT_ATN);
NCR5380_dprint(NDEBUG_PIO, instance);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
}
} else {
NCR5380_dprint(NDEBUG_PIO, instance);
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
}
while (NCR5380_read(STATUS_REG) & SR_REQ)
;
dprintk(NDEBUG_HANDSHAKE, "scsi%d: req false, handshake complete\n", HOSTNO);
/*
* We have several special cases to consider during REQ/ACK handshaking :
* 1. We were in MSGOUT phase, and we are on the last byte of the
* message. ATN must be dropped as ACK is dropped.
*
* 2. We are in a MSGIN phase, and we are on the last byte of the
* message. We must exit with ACK asserted, so that the calling
* code may raise ATN before dropping ACK to reject the message.
*
* 3. ACK and ATN are clear and the target may proceed as normal.
*/
if (!(p == PHASE_MSGIN && c == 1)) {
if (p == PHASE_MSGOUT && c > 1)
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
else
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
}
} while (--c);
dprintk(NDEBUG_PIO, "scsi%d: residual %d\n", HOSTNO, c);
*count = c;
*data = d;
tmp = NCR5380_read(STATUS_REG);
/* The phase read from the bus is valid if either REQ is (already)
* asserted or if ACK hasn't been released yet. The latter is the case if
* we're in MSGIN and all wanted bytes have been received.
*/
if ((tmp & SR_REQ) || (p == PHASE_MSGIN && c == 0))
*phase = tmp & PHASE_MASK;
else
*phase = PHASE_UNKNOWN;
if (!c || (*phase == p))
return 0;
else
return -1;
}
/*
* Function : do_abort (Scsi_Host *host)
*
* Purpose : abort the currently established nexus. Should only be
* called from a routine which can drop into a
*
* Returns : 0 on success, -1 on failure.
*/
static int do_abort(struct Scsi_Host *host)
{
unsigned char tmp, *msgptr, phase;
int len;
/* Request message out phase */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
/*
* Wait for the target to indicate a valid phase by asserting
* REQ. Once this happens, we'll have either a MSGOUT phase
* and can immediately send the ABORT message, or we'll have some
* other phase and will have to source/sink data.
*
* We really don't care what value was on the bus or what value
* the target sees, so we just handshake.
*/
while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
;
NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
ICR_ASSERT_ACK);
while (NCR5380_read(STATUS_REG) & SR_REQ)
;
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
}
tmp = ABORT;
msgptr = &tmp;
len = 1;
phase = PHASE_MSGOUT;
NCR5380_transfer_pio(host, &phase, &len, &msgptr);
/*
* If we got here, and the command completed successfully,
* we're about to go into bus free state.
*/
return len ? -1 : 0;
}
#if defined(REAL_DMA)
/*
* Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
* unsigned char *phase, int *count, unsigned char **data)
*
* Purpose : transfers data in given phase using either real
* or pseudo DMA.
*
* Inputs : instance - instance of driver, *phase - pointer to
* what phase is expected, *count - pointer to number of
* bytes to transfer, **data - pointer to data pointer.
*
* Returns : -1 when different phase is entered without transferring
* maximum number of bytes, 0 if all bytes or transferred or exit
* is in same phase.
*
* Also, *phase, *count, *data are modified in place.
*
*/
static int NCR5380_transfer_dma(struct Scsi_Host *instance,
unsigned char *phase, int *count,
unsigned char **data)
{
SETUP_HOSTDATA(instance);
register int c = *count;
register unsigned char p = *phase;
register unsigned char *d = *data;
unsigned char tmp;
unsigned long flags;
if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
*phase = tmp;
return -1;
}
if (atari_read_overruns && (p & SR_IO))
c -= atari_read_overruns;
dprintk(NDEBUG_DMA, "scsi%d: initializing DMA for %s, %d bytes %s %p\n",
HOSTNO, (p & SR_IO) ? "reading" : "writing",
c, (p & SR_IO) ? "to" : "from", d);
NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
#ifdef REAL_DMA
NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
#endif /* def REAL_DMA */
if (IS_A_TT()) {
/* On the Medusa, it is a must to initialize the DMA before
* starting the NCR. This is also the cleaner way for the TT.
*/
local_irq_save(flags);
hostdata->dma_len = (p & SR_IO) ?
NCR5380_dma_read_setup(instance, d, c) :
NCR5380_dma_write_setup(instance, d, c);
local_irq_restore(flags);
}
if (p & SR_IO)
NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
else {
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
NCR5380_write(START_DMA_SEND_REG, 0);
}
if (!IS_A_TT()) {
/* On the Falcon, the DMA setup must be done after the last */
/* NCR access, else the DMA setup gets trashed!
*/
local_irq_save(flags);
hostdata->dma_len = (p & SR_IO) ?
NCR5380_dma_read_setup(instance, d, c) :
NCR5380_dma_write_setup(instance, d, c);
local_irq_restore(flags);
}
return 0;
}
#endif /* defined(REAL_DMA) */
/*
* Function : NCR5380_information_transfer (struct Scsi_Host *instance)
*
* Purpose : run through the various SCSI phases and do as the target
* directs us to. Operates on the currently connected command,
* instance->connected.
*
* Inputs : instance, instance for which we are doing commands
*
* Side effects : SCSI things happen, the disconnected queue will be
* modified if a command disconnects, *instance->connected will
* change.
*
* XXX Note : we need to watch for bus free or a reset condition here
* to recover from an unexpected bus free condition.
*/
static void NCR5380_information_transfer(struct Scsi_Host *instance)
{
SETUP_HOSTDATA(instance);
unsigned long flags;
unsigned char msgout = NOP;
int sink = 0;
int len;
#if defined(REAL_DMA)
int transfersize;
#endif
unsigned char *data;
unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
Scsi_Cmnd *cmd = (Scsi_Cmnd *) hostdata->connected;
while (1) {
tmp = NCR5380_read(STATUS_REG);
/* We only have a valid SCSI phase when REQ is asserted */
if (tmp & SR_REQ) {
phase = (tmp & PHASE_MASK);
if (phase != old_phase) {
old_phase = phase;
NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
}
if (sink && (phase != PHASE_MSGOUT)) {
NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
ICR_ASSERT_ACK);
while (NCR5380_read(STATUS_REG) & SR_REQ)
;
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
ICR_ASSERT_ATN);
sink = 0;
continue;
}
switch (phase) {
case PHASE_DATAOUT:
#if (NDEBUG & NDEBUG_NO_DATAOUT)
printk("scsi%d: NDEBUG_NO_DATAOUT set, attempted DATAOUT "
"aborted\n", HOSTNO);
sink = 1;
do_abort(instance);
cmd->result = DID_ERROR << 16;
cmd->scsi_done(cmd);
return;
#endif
case PHASE_DATAIN:
/*
* If there is no room left in the current buffer in the
* scatter-gather list, move onto the next one.
*/
if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
++cmd->SCp.buffer;
--cmd->SCp.buffers_residual;
cmd->SCp.this_residual = cmd->SCp.buffer->length;
cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
/* ++roman: Try to merge some scatter-buffers if
* they are at contiguous physical addresses.
*/
merge_contiguous_buffers(cmd);
dprintk(NDEBUG_INFORMATION, "scsi%d: %d bytes and %d buffers left\n",
HOSTNO, cmd->SCp.this_residual,
cmd->SCp.buffers_residual);
}
/*
* The preferred transfer method is going to be
* PSEUDO-DMA for systems that are strictly PIO,
* since we can let the hardware do the handshaking.
*
* For this to work, we need to know the transfersize
* ahead of time, since the pseudo-DMA code will sit
* in an unconditional loop.
*/
/* ++roman: I suggest, this should be
* #if def(REAL_DMA)
* instead of leaving REAL_DMA out.
*/
#if defined(REAL_DMA)
if (!cmd->device->borken &&
(transfersize = NCR5380_dma_xfer_len(instance,cmd,phase)) > 31) {
len = transfersize;
cmd->SCp.phase = phase;
if (NCR5380_transfer_dma(instance, &phase,
&len, (unsigned char **)&cmd->SCp.ptr)) {
/*
* If the watchdog timer fires, all future
* accesses to this device will use the
* polled-IO. */
printk(KERN_NOTICE "scsi%d: switching target %d "
"lun %llu to slow handshake\n", HOSTNO,
cmd->device->id, cmd->device->lun);
cmd->device->borken = 1;
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
ICR_ASSERT_ATN);
sink = 1;
do_abort(instance);
cmd->result = DID_ERROR << 16;
cmd->scsi_done(cmd);
/* XXX - need to source or sink data here, as appropriate */
} else {
#ifdef REAL_DMA
/* ++roman: When using real DMA,
* information_transfer() should return after
* starting DMA since it has nothing more to
* do.
*/
return;
#else
cmd->SCp.this_residual -= transfersize - len;
#endif
}
} else
#endif /* defined(REAL_DMA) */
NCR5380_transfer_pio(instance, &phase,
(int *)&cmd->SCp.this_residual,
(unsigned char **)&cmd->SCp.ptr);
break;
case PHASE_MSGIN:
len = 1;
data = &tmp;
NCR5380_write(SELECT_ENABLE_REG, 0); /* disable reselects */
NCR5380_transfer_pio(instance, &phase, &len, &data);
cmd->SCp.Message = tmp;
switch (tmp) {
/*
* Linking lets us reduce the time required to get the
* next command out to the device, hopefully this will
* mean we don't waste another revolution due to the delays
* required by ARBITRATION and another SELECTION.
*
* In the current implementation proposal, low level drivers
* merely have to start the next command, pointed to by
* next_link, done() is called as with unlinked commands.
*/
#ifdef LINKED
case LINKED_CMD_COMPLETE:
case LINKED_FLG_CMD_COMPLETE:
/* Accept message by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
dprintk(NDEBUG_LINKED, "scsi%d: target %d lun %llu linked command "
"complete.\n", HOSTNO, cmd->device->id, cmd->device->lun);
/* Enable reselect interrupts */
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
/*
* Sanity check : A linked command should only terminate
* with one of these messages if there are more linked
* commands available.
*/
if (!cmd->next_link) {
printk(KERN_NOTICE "scsi%d: target %d lun %llu "
"linked command complete, no next_link\n",
HOSTNO, cmd->device->id, cmd->device->lun);
sink = 1;
do_abort(instance);
return;
}
initialize_SCp(cmd->next_link);
/* The next command is still part of this process; copy it
* and don't free it! */
cmd->next_link->tag = cmd->tag;
cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
dprintk(NDEBUG_LINKED, "scsi%d: target %d lun %llu linked request "
"done, calling scsi_done().\n",
HOSTNO, cmd->device->id, cmd->device->lun);
#ifdef NCR5380_STATS
collect_stats(hostdata, cmd);
#endif
cmd->scsi_done(cmd);
cmd = hostdata->connected;
break;
#endif /* def LINKED */
case ABORT:
case COMMAND_COMPLETE:
/* Accept message by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
/* ++guenther: possible race with Falcon locking */
falcon_dont_release++;
hostdata->connected = NULL;
dprintk(NDEBUG_QUEUES, "scsi%d: command for target %d, lun %llu "
"completed\n", HOSTNO, cmd->device->id, cmd->device->lun);
#ifdef SUPPORT_TAGS
cmd_free_tag(cmd);
if (status_byte(cmd->SCp.Status) == QUEUE_FULL) {
/* Turn a QUEUE FULL status into BUSY, I think the
* mid level cannot handle QUEUE FULL :-( (The
* command is retried after BUSY). Also update our
* queue size to the number of currently issued
* commands now.
*/
/* ++Andreas: the mid level code knows about
QUEUE_FULL now. */
TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %llu returned "
"QUEUE_FULL after %d commands\n",
HOSTNO, cmd->device->id, cmd->device->lun,
ta->nr_allocated);
if (ta->queue_size > ta->nr_allocated)
ta->nr_allocated = ta->queue_size;
}
#else
hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
#endif
/* Enable reselect interrupts */
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
/*
* I'm not sure what the correct thing to do here is :
*
* If the command that just executed is NOT a request
* sense, the obvious thing to do is to set the result
* code to the values of the stored parameters.
*
* If it was a REQUEST SENSE command, we need some way to
* differentiate between the failure code of the original
* and the failure code of the REQUEST sense - the obvious
* case is success, where we fall through and leave the
* result code unchanged.
*
* The non-obvious place is where the REQUEST SENSE failed
*/
if (cmd->cmnd[0] != REQUEST_SENSE)
cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
else if (status_byte(cmd->SCp.Status) != GOOD)
cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
#ifdef AUTOSENSE
if ((cmd->cmnd[0] == REQUEST_SENSE) &&
hostdata->ses.cmd_len) {
scsi_eh_restore_cmnd(cmd, &hostdata->ses);
hostdata->ses.cmd_len = 0 ;
}
if ((cmd->cmnd[0] != REQUEST_SENSE) &&
(status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
dprintk(NDEBUG_AUTOSENSE, "scsi%d: performing request sense\n", HOSTNO);
local_irq_save(flags);
LIST(cmd,hostdata->issue_queue);
SET_NEXT(cmd, hostdata->issue_queue);
hostdata->issue_queue = (Scsi_Cmnd *) cmd;
local_irq_restore(flags);
dprintk(NDEBUG_QUEUES, "scsi%d: REQUEST SENSE added to head of "
"issue queue\n", H_NO(cmd));
} else
#endif /* def AUTOSENSE */
{
#ifdef NCR5380_STATS
collect_stats(hostdata, cmd);
#endif
cmd->scsi_done(cmd);
}
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
/*
* Restore phase bits to 0 so an interrupted selection,
* arbitration can resume.
*/
NCR5380_write(TARGET_COMMAND_REG, 0);
while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
barrier();
falcon_dont_release--;
/* ++roman: For Falcon SCSI, release the lock on the
* ST-DMA here if no other commands are waiting on the
* disconnected queue.
*/
falcon_release_lock_if_possible(hostdata);
return;
case MESSAGE_REJECT:
/* Accept message by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
/* Enable reselect interrupts */
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
switch (hostdata->last_message) {
case HEAD_OF_QUEUE_TAG:
case ORDERED_QUEUE_TAG:
case SIMPLE_QUEUE_TAG:
/* The target obviously doesn't support tagged
* queuing, even though it announced this ability in
* its INQUIRY data ?!? (maybe only this LUN?) Ok,
* clear 'tagged_supported' and lock the LUN, since
* the command is treated as untagged further on.
*/
cmd->device->tagged_supported = 0;
hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
cmd->tag = TAG_NONE;
dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %llu rejected "
"QUEUE_TAG message; tagged queuing "
"disabled\n",
HOSTNO, cmd->device->id, cmd->device->lun);
break;
}
break;
case DISCONNECT:
/* Accept message by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
local_irq_save(flags);
cmd->device->disconnect = 1;
LIST(cmd,hostdata->disconnected_queue);
SET_NEXT(cmd, hostdata->disconnected_queue);
hostdata->connected = NULL;
hostdata->disconnected_queue = cmd;
local_irq_restore(flags);
dprintk(NDEBUG_QUEUES, "scsi%d: command for target %d lun %llu was "
"moved from connected to the "
"disconnected_queue\n", HOSTNO,
cmd->device->id, cmd->device->lun);
/*
* Restore phase bits to 0 so an interrupted selection,
* arbitration can resume.
*/
NCR5380_write(TARGET_COMMAND_REG, 0);
/* Enable reselect interrupts */
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
/* Wait for bus free to avoid nasty timeouts */
while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
barrier();
return;
/*
* The SCSI data pointer is *IMPLICITLY* saved on a disconnect
* operation, in violation of the SCSI spec so we can safely
* ignore SAVE/RESTORE pointers calls.
*
* Unfortunately, some disks violate the SCSI spec and
* don't issue the required SAVE_POINTERS message before
* disconnecting, and we have to break spec to remain
* compatible.
*/
case SAVE_POINTERS:
case RESTORE_POINTERS:
/* Accept message by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
/* Enable reselect interrupts */
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
break;
case EXTENDED_MESSAGE:
/*
* Extended messages are sent in the following format :
* Byte
* 0 EXTENDED_MESSAGE == 1
* 1 length (includes one byte for code, doesn't
* include first two bytes)
* 2 code
* 3..length+1 arguments
*
* Start the extended message buffer with the EXTENDED_MESSAGE
* byte, since spi_print_msg() wants the whole thing.
*/
extended_msg[0] = EXTENDED_MESSAGE;
/* Accept first byte by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
dprintk(NDEBUG_EXTENDED, "scsi%d: receiving extended message\n", HOSTNO);
len = 2;
data = extended_msg + 1;
phase = PHASE_MSGIN;
NCR5380_transfer_pio(instance, &phase, &len, &data);
dprintk(NDEBUG_EXTENDED, "scsi%d: length=%d, code=0x%02x\n", HOSTNO,
(int)extended_msg[1], (int)extended_msg[2]);
if (!len && extended_msg[1] <=
(sizeof(extended_msg) - 1)) {
/* Accept third byte by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
len = extended_msg[1] - 1;
data = extended_msg + 3;
phase = PHASE_MSGIN;
NCR5380_transfer_pio(instance, &phase, &len, &data);
dprintk(NDEBUG_EXTENDED, "scsi%d: message received, residual %d\n",
HOSTNO, len);
switch (extended_msg[2]) {
case EXTENDED_SDTR:
case EXTENDED_WDTR:
case EXTENDED_MODIFY_DATA_POINTER:
case EXTENDED_EXTENDED_IDENTIFY:
tmp = 0;
}
} else if (len) {
printk(KERN_NOTICE "scsi%d: error receiving "
"extended message\n", HOSTNO);
tmp = 0;
} else {
printk(KERN_NOTICE "scsi%d: extended message "
"code %02x length %d is too long\n",
HOSTNO, extended_msg[2], extended_msg[1]);
tmp = 0;
}
/* Fall through to reject message */
/*
* If we get something weird that we aren't expecting,
* reject it.
*/
default:
if (!tmp) {
printk(KERN_DEBUG "scsi%d: rejecting message ", HOSTNO);
spi_print_msg(extended_msg);
printk("\n");
} else if (tmp != EXTENDED_MESSAGE)
printk(KERN_DEBUG "scsi%d: rejecting unknown "
"message %02x from target %d, lun %llu\n",
HOSTNO, tmp, cmd->device->id, cmd->device->lun);
else
printk(KERN_DEBUG "scsi%d: rejecting unknown "
"extended message "
"code %02x, length %d from target %d, lun %llu\n",
HOSTNO, extended_msg[1], extended_msg[0],
cmd->device->id, cmd->device->lun);
msgout = MESSAGE_REJECT;
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
break;
} /* switch (tmp) */
break;
case PHASE_MSGOUT:
len = 1;
data = &msgout;
hostdata->last_message = msgout;
NCR5380_transfer_pio(instance, &phase, &len, &data);
if (msgout == ABORT) {
#ifdef SUPPORT_TAGS
cmd_free_tag(cmd);
#else
hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
#endif
hostdata->connected = NULL;
cmd->result = DID_ERROR << 16;
#ifdef NCR5380_STATS
collect_stats(hostdata, cmd);
#endif
cmd->scsi_done(cmd);
NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
falcon_release_lock_if_possible(hostdata);
return;
}
msgout = NOP;
break;
case PHASE_CMDOUT:
len = cmd->cmd_len;
data = cmd->cmnd;
/*
* XXX for performance reasons, on machines with a
* PSEUDO-DMA architecture we should probably
* use the dma transfer function.
*/
NCR5380_transfer_pio(instance, &phase, &len, &data);
break;
case PHASE_STATIN:
len = 1;
data = &tmp;
NCR5380_transfer_pio(instance, &phase, &len, &data);
cmd->SCp.Status = tmp;
break;
default:
printk("scsi%d: unknown phase\n", HOSTNO);
NCR5380_dprint(NDEBUG_ANY, instance);
} /* switch(phase) */
} /* if (tmp * SR_REQ) */
} /* while (1) */
}
/*
* Function : void NCR5380_reselect (struct Scsi_Host *instance)
*
* Purpose : does reselection, initializing the instance->connected
* field to point to the Scsi_Cmnd for which the I_T_L or I_T_L_Q
* nexus has been reestablished,
*
* Inputs : instance - this instance of the NCR5380.
*
*/
static void NCR5380_reselect(struct Scsi_Host *instance)
{
SETUP_HOSTDATA(instance);
unsigned char target_mask;
unsigned char lun, phase;
int len;
#ifdef SUPPORT_TAGS
unsigned char tag;
#endif
unsigned char msg[3];
unsigned char *data;
Scsi_Cmnd *tmp = NULL, *prev;
/* unsigned long flags; */
/*
* Disable arbitration, etc. since the host adapter obviously
* lost, and tell an interrupted NCR5380_select() to restart.
*/
NCR5380_write(MODE_REG, MR_BASE);
hostdata->restart_select = 1;
target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
dprintk(NDEBUG_RESELECTION, "scsi%d: reselect\n", HOSTNO);
/*
* At this point, we have detected that our SCSI ID is on the bus,
* SEL is true and BSY was false for at least one bus settle delay
* (400 ns).
*
* We must assert BSY ourselves, until the target drops the SEL
* signal.
*/
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
while (NCR5380_read(STATUS_REG) & SR_SEL)
;
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
/*
* Wait for target to go into MSGIN.
*/
while (!(NCR5380_read(STATUS_REG) & SR_REQ))
;
len = 1;
data = msg;
phase = PHASE_MSGIN;
NCR5380_transfer_pio(instance, &phase, &len, &data);
if (!(msg[0] & 0x80)) {
printk(KERN_DEBUG "scsi%d: expecting IDENTIFY message, got ", HOSTNO);
spi_print_msg(msg);
do_abort(instance);
return;
}
lun = (msg[0] & 0x07);
#ifdef SUPPORT_TAGS
/* If the phase is still MSGIN, the target wants to send some more
* messages. In case it supports tagged queuing, this is probably a
* SIMPLE_QUEUE_TAG for the I_T_L_Q nexus.
*/
tag = TAG_NONE;
if (phase == PHASE_MSGIN && setup_use_tagged_queuing) {
/* Accept previous IDENTIFY message by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
len = 2;
data = msg + 1;
if (!NCR5380_transfer_pio(instance, &phase, &len, &data) &&
msg[1] == SIMPLE_QUEUE_TAG)
tag = msg[2];
dprintk(NDEBUG_TAGS, "scsi%d: target mask %02x, lun %d sent tag %d at "
"reselection\n", HOSTNO, target_mask, lun, tag);
}
#endif
/*
* Find the command corresponding to the I_T_L or I_T_L_Q nexus we
* just reestablished, and remove it from the disconnected queue.
*/
for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue, prev = NULL;
tmp; prev = tmp, tmp = NEXT(tmp)) {
if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
#ifdef SUPPORT_TAGS
&& (tag == tmp->tag)
#endif
) {
/* ++guenther: prevent race with falcon_release_lock */
falcon_dont_release++;
if (prev) {
REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
SET_NEXT(prev, NEXT(tmp));
} else {
REMOVE(-1, hostdata->disconnected_queue, tmp, NEXT(tmp));
hostdata->disconnected_queue = NEXT(tmp);
}
SET_NEXT(tmp, NULL);
break;
}
}
if (!tmp) {
printk(KERN_WARNING "scsi%d: warning: target bitmask %02x lun %d "
#ifdef SUPPORT_TAGS
"tag %d "
#endif
"not in disconnected_queue.\n",
HOSTNO, target_mask, lun
#ifdef SUPPORT_TAGS
, tag
#endif
);
/*
* Since we have an established nexus that we can't do anything
* with, we must abort it.
*/
do_abort(instance);
return;
}
/* Accept message by clearing ACK */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
hostdata->connected = tmp;
dprintk(NDEBUG_RESELECTION, "scsi%d: nexus established, target = %d, lun = %llu, tag = %d\n",
HOSTNO, tmp->device->id, tmp->device->lun, tmp->tag);
falcon_dont_release--;
}
/*
* Function : int NCR5380_abort (Scsi_Cmnd *cmd)
*
* Purpose : abort a command
*
* Inputs : cmd - the Scsi_Cmnd to abort, code - code to set the
* host byte of the result field to, if zero DID_ABORTED is
* used.
*
* Returns : 0 - success, -1 on failure.
*
* XXX - there is no way to abort the command that is currently
* connected, you have to wait for it to complete. If this is
* a problem, we could implement longjmp() / setjmp(), setjmp()
* called where the loop started in NCR5380_main().
*/
static
int NCR5380_abort(Scsi_Cmnd *cmd)
{
struct Scsi_Host *instance = cmd->device->host;
SETUP_HOSTDATA(instance);
Scsi_Cmnd *tmp, **prev;
unsigned long flags;
printk(KERN_NOTICE "scsi%d: aborting command\n", HOSTNO);
scsi_print_command(cmd);
NCR5380_print_status(instance);
local_irq_save(flags);
if (!IS_A_TT() && !falcon_got_lock)
printk(KERN_ERR "scsi%d: !!BINGO!! Falcon has no lock in NCR5380_abort\n",
HOSTNO);
dprintk(NDEBUG_ABORT, "scsi%d: abort called basr 0x%02x, sr 0x%02x\n", HOSTNO,
NCR5380_read(BUS_AND_STATUS_REG),
NCR5380_read(STATUS_REG));
#if 1
/*
* Case 1 : If the command is the currently executing command,
* we'll set the aborted flag and return control so that
* information transfer routine can exit cleanly.
*/
if (hostdata->connected == cmd) {
dprintk(NDEBUG_ABORT, "scsi%d: aborting connected command\n", HOSTNO);
/*
* We should perform BSY checking, and make sure we haven't slipped
* into BUS FREE.
*/
/* NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN); */
/*
* Since we can't change phases until we've completed the current
* handshake, we have to source or sink a byte of data if the current
* phase is not MSGOUT.
*/
/*
* Return control to the executing NCR drive so we can clear the
* aborted flag and get back into our main loop.
*/
if (do_abort(instance) == 0) {
hostdata->aborted = 1;
hostdata->connected = NULL;
cmd->result = DID_ABORT << 16;
#ifdef SUPPORT_TAGS
cmd_free_tag(cmd);
#else
hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
#endif
local_irq_restore(flags);
cmd->scsi_done(cmd);
falcon_release_lock_if_possible(hostdata);
return SUCCESS;
} else {
/* local_irq_restore(flags); */
printk("scsi%d: abort of connected command failed!\n", HOSTNO);
return FAILED;
}
}
#endif
/*
* Case 2 : If the command hasn't been issued yet, we simply remove it
* from the issue queue.
*/
for (prev = (Scsi_Cmnd **)&(hostdata->issue_queue),
tmp = (Scsi_Cmnd *)hostdata->issue_queue;
tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
if (cmd == tmp) {
REMOVE(5, *prev, tmp, NEXT(tmp));
(*prev) = NEXT(tmp);
SET_NEXT(tmp, NULL);
tmp->result = DID_ABORT << 16;
local_irq_restore(flags);
dprintk(NDEBUG_ABORT, "scsi%d: abort removed command from issue queue.\n",
HOSTNO);
/* Tagged queuing note: no tag to free here, hasn't been assigned
* yet... */
tmp->scsi_done(tmp);
falcon_release_lock_if_possible(hostdata);
return SUCCESS;
}
}
/*
* Case 3 : If any commands are connected, we're going to fail the abort
* and let the high level SCSI driver retry at a later time or
* issue a reset.
*
* Timeouts, and therefore aborted commands, will be highly unlikely
* and handling them cleanly in this situation would make the common
* case of noresets less efficient, and would pollute our code. So,
* we fail.
*/
if (hostdata->connected) {
local_irq_restore(flags);
dprintk(NDEBUG_ABORT, "scsi%d: abort failed, command connected.\n", HOSTNO);
return FAILED;
}
/*
* Case 4: If the command is currently disconnected from the bus, and
* there are no connected commands, we reconnect the I_T_L or
* I_T_L_Q nexus associated with it, go into message out, and send
* an abort message.
*
* This case is especially ugly. In order to reestablish the nexus, we
* need to call NCR5380_select(). The easiest way to implement this
* function was to abort if the bus was busy, and let the interrupt
* handler triggered on the SEL for reselect take care of lost arbitrations
* where necessary, meaning interrupts need to be enabled.
*
* When interrupts are enabled, the queues may change - so we
* can't remove it from the disconnected queue before selecting it
* because that could cause a failure in hashing the nexus if that
* device reselected.
*
* Since the queues may change, we can't use the pointers from when we
* first locate it.
*
* So, we must first locate the command, and if NCR5380_select()
* succeeds, then issue the abort, relocate the command and remove
* it from the disconnected queue.
*/
for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp;
tmp = NEXT(tmp)) {
if (cmd == tmp) {
local_irq_restore(flags);
dprintk(NDEBUG_ABORT, "scsi%d: aborting disconnected command.\n", HOSTNO);
if (NCR5380_select(instance, cmd, (int)cmd->tag))
return FAILED;
dprintk(NDEBUG_ABORT, "scsi%d: nexus reestablished.\n", HOSTNO);
do_abort(instance);
local_irq_save(flags);
for (prev = (Scsi_Cmnd **)&(hostdata->disconnected_queue),
tmp = (Scsi_Cmnd *)hostdata->disconnected_queue;
tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
if (cmd == tmp) {
REMOVE(5, *prev, tmp, NEXT(tmp));
*prev = NEXT(tmp);
SET_NEXT(tmp, NULL);
tmp->result = DID_ABORT << 16;
/* We must unlock the tag/LUN immediately here, since the
* target goes to BUS FREE and doesn't send us another
* message (COMMAND_COMPLETE or the like)
*/
#ifdef SUPPORT_TAGS
cmd_free_tag(tmp);
#else
hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
#endif
local_irq_restore(flags);
tmp->scsi_done(tmp);
falcon_release_lock_if_possible(hostdata);
return SUCCESS;
}
}
}
}
/*
* Case 5 : If we reached this point, the command was not found in any of
* the queues.
*
* We probably reached this point because of an unlikely race condition
* between the command completing successfully and the abortion code,
* so we won't panic, but we will notify the user in case something really
* broke.
*/
local_irq_restore(flags);
printk(KERN_INFO "scsi%d: warning : SCSI command probably completed successfully before abortion\n", HOSTNO);
/* Maybe it is sufficient just to release the ST-DMA lock... (if
* possible at all) At least, we should check if the lock could be
* released after the abort, in case it is kept due to some bug.
*/
falcon_release_lock_if_possible(hostdata);
return FAILED;
}
/*
* Function : int NCR5380_reset (Scsi_Cmnd *cmd)
*
* Purpose : reset the SCSI bus.
*
* Returns : SUCCESS or FAILURE
*
*/
static int NCR5380_bus_reset(Scsi_Cmnd *cmd)
{
SETUP_HOSTDATA(cmd->device->host);
int i;
unsigned long flags;
#if defined(RESET_RUN_DONE)
Scsi_Cmnd *connected, *disconnected_queue;
#endif
if (!IS_A_TT() && !falcon_got_lock)
printk(KERN_ERR "scsi%d: !!BINGO!! Falcon has no lock in NCR5380_reset\n",
H_NO(cmd));
NCR5380_print_status(cmd->device->host);
/* get in phase */
NCR5380_write(TARGET_COMMAND_REG,
PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG)));
/* assert RST */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
udelay(40);
/* reset NCR registers */
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
NCR5380_write(MODE_REG, MR_BASE);
NCR5380_write(TARGET_COMMAND_REG, 0);
NCR5380_write(SELECT_ENABLE_REG, 0);
/* ++roman: reset interrupt condition! otherwise no interrupts don't get
* through anymore ... */
(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
/* MSch 20140115 - looking at the generic NCR5380 driver, all of this
* should go.
* Catch-22: if we don't clear all queues, the SCSI driver lock will
* not be reset by atari_scsi_reset()!
*/
#if defined(RESET_RUN_DONE)
/* XXX Should now be done by midlevel code, but it's broken XXX */
/* XXX see below XXX */
/* MSch: old-style reset: actually abort all command processing here */
/* After the reset, there are no more connected or disconnected commands
* and no busy units; to avoid problems with re-inserting the commands
* into the issue_queue (via scsi_done()), the aborted commands are
* remembered in local variables first.
*/
local_irq_save(flags);
connected = (Scsi_Cmnd *)hostdata->connected;
hostdata->connected = NULL;
disconnected_queue = (Scsi_Cmnd *)hostdata->disconnected_queue;
hostdata->disconnected_queue = NULL;
#ifdef SUPPORT_TAGS
free_all_tags();
#endif
for (i = 0; i < 8; ++i)
hostdata->busy[i] = 0;
#ifdef REAL_DMA
hostdata->dma_len = 0;
#endif
local_irq_restore(flags);
/* In order to tell the mid-level code which commands were aborted,
* set the command status to DID_RESET and call scsi_done() !!!
* This ultimately aborts processing of these commands in the mid-level.
*/
if ((cmd = connected)) {
dprintk(NDEBUG_ABORT, "scsi%d: reset aborted a connected command\n", H_NO(cmd));
cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
cmd->scsi_done(cmd);
}
for (i = 0; (cmd = disconnected_queue); ++i) {
disconnected_queue = NEXT(cmd);
SET_NEXT(cmd, NULL);
cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
cmd->scsi_done(cmd);
}
if (i > 0)
dprintk(NDEBUG_ABORT, "scsi: reset aborted %d disconnected command(s)\n", i);
/* The Falcon lock should be released after a reset...
*/
/* ++guenther: moved to atari_scsi_reset(), to prevent a race between
* unlocking and enabling dma interrupt.
*/
/* falcon_release_lock_if_possible( hostdata );*/
/* since all commands have been explicitly terminated, we need to tell
* the midlevel code that the reset was SUCCESSFUL, and there is no
* need to 'wake up' the commands by a request_sense
*/
return SUCCESS;
#else /* 1 */
/* MSch: new-style reset handling: let the mid-level do what it can */
/* ++guenther: MID-LEVEL IS STILL BROKEN.
* Mid-level is supposed to requeue all commands that were active on the
* various low-level queues. In fact it does this, but that's not enough
* because all these commands are subject to timeout. And if a timeout
* happens for any removed command, *_abort() is called but all queues
* are now empty. Abort then gives up the falcon lock, which is fatal,
* since the mid-level will queue more commands and must have the lock
* (it's all happening inside timer interrupt handler!!).
* Even worse, abort will return NOT_RUNNING for all those commands not
* on any queue, so they won't be retried ...
*
* Conclusion: either scsi.c disables timeout for all resetted commands
* immediately, or we lose! As of linux-2.0.20 it doesn't.
*/
/* After the reset, there are no more connected or disconnected commands
* and no busy units; so clear the low-level status here to avoid
* conflicts when the mid-level code tries to wake up the affected
* commands!
*/
if (hostdata->issue_queue)
dprintk(NDEBUG_ABORT, "scsi%d: reset aborted issued command(s)\n", H_NO(cmd));
if (hostdata->connected)
dprintk(NDEBUG_ABORT, "scsi%d: reset aborted a connected command\n", H_NO(cmd));
if (hostdata->disconnected_queue)
dprintk(NDEBUG_ABORT, "scsi%d: reset aborted disconnected command(s)\n", H_NO(cmd));
local_irq_save(flags);
hostdata->issue_queue = NULL;
hostdata->connected = NULL;
hostdata->disconnected_queue = NULL;
#ifdef SUPPORT_TAGS
free_all_tags();
#endif
for (i = 0; i < 8; ++i)
hostdata->busy[i] = 0;
#ifdef REAL_DMA
hostdata->dma_len = 0;
#endif
local_irq_restore(flags);
/* we did no complete reset of all commands, so a wakeup is required */
return SUCCESS;
#endif /* 1 */
}