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/s390/block/dasd.c b/drivers/s390/block/dasd.c
new file mode 100644
index 0000000..b755bac
--- /dev/null
+++ b/drivers/s390/block/dasd.c
@@ -0,0 +1,2065 @@
+/*
+ * File...........: linux/drivers/s390/block/dasd.c
+ * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
+ * Horst Hummel <Horst.Hummel@de.ibm.com>
+ * Carsten Otte <Cotte@de.ibm.com>
+ * Martin Schwidefsky <schwidefsky@de.ibm.com>
+ * Bugreports.to..: <Linux390@de.ibm.com>
+ * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001
+ *
+ * $Revision: 1.158 $
+ */
+
+#include <linux/config.h>
+#include <linux/kmod.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/ctype.h>
+#include <linux/major.h>
+#include <linux/slab.h>
+#include <linux/buffer_head.h>
+
+#include <asm/ccwdev.h>
+#include <asm/ebcdic.h>
+#include <asm/idals.h>
+#include <asm/todclk.h>
+
+/* This is ugly... */
+#define PRINTK_HEADER "dasd:"
+
+#include "dasd_int.h"
+/*
+ * SECTION: Constant definitions to be used within this file
+ */
+#define DASD_CHANQ_MAX_SIZE 4
+
+/*
+ * SECTION: exported variables of dasd.c
+ */
+debug_info_t *dasd_debug_area;
+struct dasd_discipline *dasd_diag_discipline_pointer;
+
+MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
+MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
+ " Copyright 2000 IBM Corporation");
+MODULE_SUPPORTED_DEVICE("dasd");
+MODULE_PARM(dasd, "1-" __MODULE_STRING(256) "s");
+MODULE_LICENSE("GPL");
+
+/*
+ * SECTION: prototypes for static functions of dasd.c
+ */
+static int dasd_alloc_queue(struct dasd_device * device);
+static void dasd_setup_queue(struct dasd_device * device);
+static void dasd_free_queue(struct dasd_device * device);
+static void dasd_flush_request_queue(struct dasd_device *);
+static void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
+static void dasd_flush_ccw_queue(struct dasd_device *, int);
+static void dasd_tasklet(struct dasd_device *);
+static void do_kick_device(void *data);
+
+/*
+ * SECTION: Operations on the device structure.
+ */
+static wait_queue_head_t dasd_init_waitq;
+
+/*
+ * Allocate memory for a new device structure.
+ */
+struct dasd_device *
+dasd_alloc_device(void)
+{
+ struct dasd_device *device;
+
+ device = kmalloc(sizeof (struct dasd_device), GFP_ATOMIC);
+ if (device == NULL)
+ return ERR_PTR(-ENOMEM);
+ memset(device, 0, sizeof (struct dasd_device));
+ /* open_count = 0 means device online but not in use */
+ atomic_set(&device->open_count, -1);
+
+ /* Get two pages for normal block device operations. */
+ device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
+ if (device->ccw_mem == NULL) {
+ kfree(device);
+ return ERR_PTR(-ENOMEM);
+ }
+ /* Get one page for error recovery. */
+ device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
+ if (device->erp_mem == NULL) {
+ free_pages((unsigned long) device->ccw_mem, 1);
+ kfree(device);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
+ dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
+ spin_lock_init(&device->mem_lock);
+ spin_lock_init(&device->request_queue_lock);
+ atomic_set (&device->tasklet_scheduled, 0);
+ tasklet_init(&device->tasklet,
+ (void (*)(unsigned long)) dasd_tasklet,
+ (unsigned long) device);
+ INIT_LIST_HEAD(&device->ccw_queue);
+ init_timer(&device->timer);
+ INIT_WORK(&device->kick_work, do_kick_device, device);
+ device->state = DASD_STATE_NEW;
+ device->target = DASD_STATE_NEW;
+
+ return device;
+}
+
+/*
+ * Free memory of a device structure.
+ */
+void
+dasd_free_device(struct dasd_device *device)
+{
+ if (device->private)
+ kfree(device->private);
+ free_page((unsigned long) device->erp_mem);
+ free_pages((unsigned long) device->ccw_mem, 1);
+ kfree(device);
+}
+
+/*
+ * Make a new device known to the system.
+ */
+static inline int
+dasd_state_new_to_known(struct dasd_device *device)
+{
+ int rc;
+
+ /*
+ * As long as the device is not in state DASD_STATE_NEW we want to
+ * keep the reference count > 0.
+ */
+ dasd_get_device(device);
+
+ rc = dasd_alloc_queue(device);
+ if (rc) {
+ dasd_put_device(device);
+ return rc;
+ }
+
+ device->state = DASD_STATE_KNOWN;
+ return 0;
+}
+
+/*
+ * Let the system forget about a device.
+ */
+static inline void
+dasd_state_known_to_new(struct dasd_device * device)
+{
+ /* Forget the discipline information. */
+ device->discipline = NULL;
+ device->state = DASD_STATE_NEW;
+
+ dasd_free_queue(device);
+
+ /* Give up reference we took in dasd_state_new_to_known. */
+ dasd_put_device(device);
+}
+
+/*
+ * Request the irq line for the device.
+ */
+static inline int
+dasd_state_known_to_basic(struct dasd_device * device)
+{
+ int rc;
+
+ /* Allocate and register gendisk structure. */
+ rc = dasd_gendisk_alloc(device);
+ if (rc)
+ return rc;
+
+ /* register 'device' debug area, used for all DBF_DEV_XXX calls */
+ device->debug_area = debug_register(device->cdev->dev.bus_id, 0, 2,
+ 8 * sizeof (long));
+ debug_register_view(device->debug_area, &debug_sprintf_view);
+ debug_set_level(device->debug_area, DBF_EMERG);
+ DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
+
+ device->state = DASD_STATE_BASIC;
+ return 0;
+}
+
+/*
+ * Release the irq line for the device. Terminate any running i/o.
+ */
+static inline void
+dasd_state_basic_to_known(struct dasd_device * device)
+{
+ dasd_gendisk_free(device);
+ dasd_flush_ccw_queue(device, 1);
+ DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
+ if (device->debug_area != NULL) {
+ debug_unregister(device->debug_area);
+ device->debug_area = NULL;
+ }
+ device->state = DASD_STATE_KNOWN;
+}
+
+/*
+ * Do the initial analysis. The do_analysis function may return
+ * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
+ * until the discipline decides to continue the startup sequence
+ * by calling the function dasd_change_state. The eckd disciplines
+ * uses this to start a ccw that detects the format. The completion
+ * interrupt for this detection ccw uses the kernel event daemon to
+ * trigger the call to dasd_change_state. All this is done in the
+ * discipline code, see dasd_eckd.c.
+ * After the analysis ccw is done (do_analysis returned 0 or error)
+ * the block device is setup. Either a fake disk is added to allow
+ * formatting or a proper device request queue is created.
+ */
+static inline int
+dasd_state_basic_to_ready(struct dasd_device * device)
+{
+ int rc;
+
+ rc = 0;
+ if (device->discipline->do_analysis != NULL)
+ rc = device->discipline->do_analysis(device);
+ if (rc)
+ return rc;
+ dasd_setup_queue(device);
+ device->state = DASD_STATE_READY;
+ if (dasd_scan_partitions(device) != 0)
+ device->state = DASD_STATE_BASIC;
+ return 0;
+}
+
+/*
+ * Remove device from block device layer. Destroy dirty buffers.
+ * Forget format information. Check if the target level is basic
+ * and if it is create fake disk for formatting.
+ */
+static inline void
+dasd_state_ready_to_basic(struct dasd_device * device)
+{
+ dasd_flush_ccw_queue(device, 0);
+ dasd_destroy_partitions(device);
+ dasd_flush_request_queue(device);
+ device->blocks = 0;
+ device->bp_block = 0;
+ device->s2b_shift = 0;
+ device->state = DASD_STATE_BASIC;
+}
+
+/*
+ * Make the device online and schedule the bottom half to start
+ * the requeueing of requests from the linux request queue to the
+ * ccw queue.
+ */
+static inline int
+dasd_state_ready_to_online(struct dasd_device * device)
+{
+ device->state = DASD_STATE_ONLINE;
+ dasd_schedule_bh(device);
+ return 0;
+}
+
+/*
+ * Stop the requeueing of requests again.
+ */
+static inline void
+dasd_state_online_to_ready(struct dasd_device * device)
+{
+ device->state = DASD_STATE_READY;
+}
+
+/*
+ * Device startup state changes.
+ */
+static inline int
+dasd_increase_state(struct dasd_device *device)
+{
+ int rc;
+
+ rc = 0;
+ if (device->state == DASD_STATE_NEW &&
+ device->target >= DASD_STATE_KNOWN)
+ rc = dasd_state_new_to_known(device);
+
+ if (!rc &&
+ device->state == DASD_STATE_KNOWN &&
+ device->target >= DASD_STATE_BASIC)
+ rc = dasd_state_known_to_basic(device);
+
+ if (!rc &&
+ device->state == DASD_STATE_BASIC &&
+ device->target >= DASD_STATE_READY)
+ rc = dasd_state_basic_to_ready(device);
+
+ if (!rc &&
+ device->state == DASD_STATE_READY &&
+ device->target >= DASD_STATE_ONLINE)
+ rc = dasd_state_ready_to_online(device);
+
+ return rc;
+}
+
+/*
+ * Device shutdown state changes.
+ */
+static inline int
+dasd_decrease_state(struct dasd_device *device)
+{
+ if (device->state == DASD_STATE_ONLINE &&
+ device->target <= DASD_STATE_READY)
+ dasd_state_online_to_ready(device);
+
+ if (device->state == DASD_STATE_READY &&
+ device->target <= DASD_STATE_BASIC)
+ dasd_state_ready_to_basic(device);
+
+ if (device->state == DASD_STATE_BASIC &&
+ device->target <= DASD_STATE_KNOWN)
+ dasd_state_basic_to_known(device);
+
+ if (device->state == DASD_STATE_KNOWN &&
+ device->target <= DASD_STATE_NEW)
+ dasd_state_known_to_new(device);
+
+ return 0;
+}
+
+/*
+ * This is the main startup/shutdown routine.
+ */
+static void
+dasd_change_state(struct dasd_device *device)
+{
+ int rc;
+
+ if (device->state == device->target)
+ /* Already where we want to go today... */
+ return;
+ if (device->state < device->target)
+ rc = dasd_increase_state(device);
+ else
+ rc = dasd_decrease_state(device);
+ if (rc && rc != -EAGAIN)
+ device->target = device->state;
+
+ if (device->state == device->target)
+ wake_up(&dasd_init_waitq);
+}
+
+/*
+ * Kick starter for devices that did not complete the startup/shutdown
+ * procedure or were sleeping because of a pending state.
+ * dasd_kick_device will schedule a call do do_kick_device to the kernel
+ * event daemon.
+ */
+static void
+do_kick_device(void *data)
+{
+ struct dasd_device *device;
+
+ device = (struct dasd_device *) data;
+ dasd_change_state(device);
+ dasd_schedule_bh(device);
+ dasd_put_device(device);
+}
+
+void
+dasd_kick_device(struct dasd_device *device)
+{
+ dasd_get_device(device);
+ /* queue call to dasd_kick_device to the kernel event daemon. */
+ schedule_work(&device->kick_work);
+}
+
+/*
+ * Set the target state for a device and starts the state change.
+ */
+void
+dasd_set_target_state(struct dasd_device *device, int target)
+{
+ /* If we are in probeonly mode stop at DASD_STATE_READY. */
+ if (dasd_probeonly && target > DASD_STATE_READY)
+ target = DASD_STATE_READY;
+ if (device->target != target) {
+ if (device->state == target)
+ wake_up(&dasd_init_waitq);
+ device->target = target;
+ }
+ if (device->state != device->target)
+ dasd_change_state(device);
+}
+
+/*
+ * Enable devices with device numbers in [from..to].
+ */
+static inline int
+_wait_for_device(struct dasd_device *device)
+{
+ return (device->state == device->target);
+}
+
+void
+dasd_enable_device(struct dasd_device *device)
+{
+ dasd_set_target_state(device, DASD_STATE_ONLINE);
+ if (device->state <= DASD_STATE_KNOWN)
+ /* No discipline for device found. */
+ dasd_set_target_state(device, DASD_STATE_NEW);
+ /* Now wait for the devices to come up. */
+ wait_event(dasd_init_waitq, _wait_for_device(device));
+}
+
+/*
+ * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
+ */
+#ifdef CONFIG_DASD_PROFILE
+
+struct dasd_profile_info_t dasd_global_profile;
+unsigned int dasd_profile_level = DASD_PROFILE_OFF;
+
+/*
+ * Increments counter in global and local profiling structures.
+ */
+#define dasd_profile_counter(value, counter, device) \
+{ \
+ int index; \
+ for (index = 0; index < 31 && value >> (2+index); index++); \
+ dasd_global_profile.counter[index]++; \
+ device->profile.counter[index]++; \
+}
+
+/*
+ * Add profiling information for cqr before execution.
+ */
+static inline void
+dasd_profile_start(struct dasd_device *device, struct dasd_ccw_req * cqr,
+ struct request *req)
+{
+ struct list_head *l;
+ unsigned int counter;
+
+ if (dasd_profile_level != DASD_PROFILE_ON)
+ return;
+
+ /* count the length of the chanq for statistics */
+ counter = 0;
+ list_for_each(l, &device->ccw_queue)
+ if (++counter >= 31)
+ break;
+ dasd_global_profile.dasd_io_nr_req[counter]++;
+ device->profile.dasd_io_nr_req[counter]++;
+}
+
+/*
+ * Add profiling information for cqr after execution.
+ */
+static inline void
+dasd_profile_end(struct dasd_device *device, struct dasd_ccw_req * cqr,
+ struct request *req)
+{
+ long strtime, irqtime, endtime, tottime; /* in microseconds */
+ long tottimeps, sectors;
+
+ if (dasd_profile_level != DASD_PROFILE_ON)
+ return;
+
+ sectors = req->nr_sectors;
+ if (!cqr->buildclk || !cqr->startclk ||
+ !cqr->stopclk || !cqr->endclk ||
+ !sectors)
+ return;
+
+ strtime = ((cqr->startclk - cqr->buildclk) >> 12);
+ irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
+ endtime = ((cqr->endclk - cqr->stopclk) >> 12);
+ tottime = ((cqr->endclk - cqr->buildclk) >> 12);
+ tottimeps = tottime / sectors;
+
+ if (!dasd_global_profile.dasd_io_reqs)
+ memset(&dasd_global_profile, 0,
+ sizeof (struct dasd_profile_info_t));
+ dasd_global_profile.dasd_io_reqs++;
+ dasd_global_profile.dasd_io_sects += sectors;
+
+ if (!device->profile.dasd_io_reqs)
+ memset(&device->profile, 0,
+ sizeof (struct dasd_profile_info_t));
+ device->profile.dasd_io_reqs++;
+ device->profile.dasd_io_sects += sectors;
+
+ dasd_profile_counter(sectors, dasd_io_secs, device);
+ dasd_profile_counter(tottime, dasd_io_times, device);
+ dasd_profile_counter(tottimeps, dasd_io_timps, device);
+ dasd_profile_counter(strtime, dasd_io_time1, device);
+ dasd_profile_counter(irqtime, dasd_io_time2, device);
+ dasd_profile_counter(irqtime / sectors, dasd_io_time2ps, device);
+ dasd_profile_counter(endtime, dasd_io_time3, device);
+}
+#else
+#define dasd_profile_start(device, cqr, req) do {} while (0)
+#define dasd_profile_end(device, cqr, req) do {} while (0)
+#endif /* CONFIG_DASD_PROFILE */
+
+/*
+ * Allocate memory for a channel program with 'cplength' channel
+ * command words and 'datasize' additional space. There are two
+ * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
+ * memory and 2) dasd_smalloc_request uses the static ccw memory
+ * that gets allocated for each device.
+ */
+struct dasd_ccw_req *
+dasd_kmalloc_request(char *magic, int cplength, int datasize,
+ struct dasd_device * device)
+{
+ struct dasd_ccw_req *cqr;
+
+ /* Sanity checks */
+ if ( magic == NULL || datasize > PAGE_SIZE ||
+ (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
+ BUG();
+
+ cqr = kmalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
+ if (cqr == NULL)
+ return ERR_PTR(-ENOMEM);
+ memset(cqr, 0, sizeof(struct dasd_ccw_req));
+ cqr->cpaddr = NULL;
+ if (cplength > 0) {
+ cqr->cpaddr = kmalloc(cplength*sizeof(struct ccw1),
+ GFP_ATOMIC | GFP_DMA);
+ if (cqr->cpaddr == NULL) {
+ kfree(cqr);
+ return ERR_PTR(-ENOMEM);
+ }
+ memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
+ }
+ cqr->data = NULL;
+ if (datasize > 0) {
+ cqr->data = kmalloc(datasize, GFP_ATOMIC | GFP_DMA);
+ if (cqr->data == NULL) {
+ if (cqr->cpaddr != NULL)
+ kfree(cqr->cpaddr);
+ kfree(cqr);
+ return ERR_PTR(-ENOMEM);
+ }
+ memset(cqr->data, 0, datasize);
+ }
+ strncpy((char *) &cqr->magic, magic, 4);
+ ASCEBC((char *) &cqr->magic, 4);
+ set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
+ dasd_get_device(device);
+ return cqr;
+}
+
+struct dasd_ccw_req *
+dasd_smalloc_request(char *magic, int cplength, int datasize,
+ struct dasd_device * device)
+{
+ unsigned long flags;
+ struct dasd_ccw_req *cqr;
+ char *data;
+ int size;
+
+ /* Sanity checks */
+ if ( magic == NULL || datasize > PAGE_SIZE ||
+ (cplength*sizeof(struct ccw1)) > PAGE_SIZE)
+ BUG();
+
+ size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
+ if (cplength > 0)
+ size += cplength * sizeof(struct ccw1);
+ if (datasize > 0)
+ size += datasize;
+ spin_lock_irqsave(&device->mem_lock, flags);
+ cqr = (struct dasd_ccw_req *)
+ dasd_alloc_chunk(&device->ccw_chunks, size);
+ spin_unlock_irqrestore(&device->mem_lock, flags);
+ if (cqr == NULL)
+ return ERR_PTR(-ENOMEM);
+ memset(cqr, 0, sizeof(struct dasd_ccw_req));
+ data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
+ cqr->cpaddr = NULL;
+ if (cplength > 0) {
+ cqr->cpaddr = (struct ccw1 *) data;
+ data += cplength*sizeof(struct ccw1);
+ memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
+ }
+ cqr->data = NULL;
+ if (datasize > 0) {
+ cqr->data = data;
+ memset(cqr->data, 0, datasize);
+ }
+ strncpy((char *) &cqr->magic, magic, 4);
+ ASCEBC((char *) &cqr->magic, 4);
+ set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
+ dasd_get_device(device);
+ return cqr;
+}
+
+/*
+ * Free memory of a channel program. This function needs to free all the
+ * idal lists that might have been created by dasd_set_cda and the
+ * struct dasd_ccw_req itself.
+ */
+void
+dasd_kfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
+{
+#ifdef CONFIG_ARCH_S390X
+ struct ccw1 *ccw;
+
+ /* Clear any idals used for the request. */
+ ccw = cqr->cpaddr;
+ do {
+ clear_normalized_cda(ccw);
+ } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
+#endif
+ if (cqr->cpaddr != NULL)
+ kfree(cqr->cpaddr);
+ if (cqr->data != NULL)
+ kfree(cqr->data);
+ kfree(cqr);
+ dasd_put_device(device);
+}
+
+void
+dasd_sfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&device->mem_lock, flags);
+ dasd_free_chunk(&device->ccw_chunks, cqr);
+ spin_unlock_irqrestore(&device->mem_lock, flags);
+ dasd_put_device(device);
+}
+
+/*
+ * Check discipline magic in cqr.
+ */
+static inline int
+dasd_check_cqr(struct dasd_ccw_req *cqr)
+{
+ struct dasd_device *device;
+
+ if (cqr == NULL)
+ return -EINVAL;
+ device = cqr->device;
+ if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
+ DEV_MESSAGE(KERN_WARNING, device,
+ " dasd_ccw_req 0x%08x magic doesn't match"
+ " discipline 0x%08x",
+ cqr->magic,
+ *(unsigned int *) device->discipline->name);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+/*
+ * Terminate the current i/o and set the request to clear_pending.
+ * Timer keeps device runnig.
+ * ccw_device_clear can fail if the i/o subsystem
+ * is in a bad mood.
+ */
+int
+dasd_term_IO(struct dasd_ccw_req * cqr)
+{
+ struct dasd_device *device;
+ int retries, rc;
+
+ /* Check the cqr */
+ rc = dasd_check_cqr(cqr);
+ if (rc)
+ return rc;
+ retries = 0;
+ device = (struct dasd_device *) cqr->device;
+ while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
+ rc = ccw_device_clear(device->cdev, (long) cqr);
+ switch (rc) {
+ case 0: /* termination successful */
+ if (cqr->retries > 0) {
+ cqr->retries--;
+ cqr->status = DASD_CQR_CLEAR;
+ } else
+ cqr->status = DASD_CQR_FAILED;
+ cqr->stopclk = get_clock();
+ DBF_DEV_EVENT(DBF_DEBUG, device,
+ "terminate cqr %p successful",
+ cqr);
+ break;
+ case -ENODEV:
+ DBF_DEV_EVENT(DBF_ERR, device, "%s",
+ "device gone, retry");
+ break;
+ case -EIO:
+ DBF_DEV_EVENT(DBF_ERR, device, "%s",
+ "I/O error, retry");
+ break;
+ case -EINVAL:
+ case -EBUSY:
+ DBF_DEV_EVENT(DBF_ERR, device, "%s",
+ "device busy, retry later");
+ break;
+ default:
+ DEV_MESSAGE(KERN_ERR, device,
+ "line %d unknown RC=%d, please "
+ "report to linux390@de.ibm.com",
+ __LINE__, rc);
+ BUG();
+ break;
+ }
+ retries++;
+ }
+ dasd_schedule_bh(device);
+ return rc;
+}
+
+/*
+ * Start the i/o. This start_IO can fail if the channel is really busy.
+ * In that case set up a timer to start the request later.
+ */
+int
+dasd_start_IO(struct dasd_ccw_req * cqr)
+{
+ struct dasd_device *device;
+ int rc;
+
+ /* Check the cqr */
+ rc = dasd_check_cqr(cqr);
+ if (rc)
+ return rc;
+ device = (struct dasd_device *) cqr->device;
+ if (cqr->retries < 0) {
+ DEV_MESSAGE(KERN_DEBUG, device,
+ "start_IO: request %p (%02x/%i) - no retry left.",
+ cqr, cqr->status, cqr->retries);
+ cqr->status = DASD_CQR_FAILED;
+ return -EIO;
+ }
+ cqr->startclk = get_clock();
+ cqr->starttime = jiffies;
+ cqr->retries--;
+ rc = ccw_device_start(device->cdev, cqr->cpaddr, (long) cqr,
+ cqr->lpm, 0);
+ switch (rc) {
+ case 0:
+ cqr->status = DASD_CQR_IN_IO;
+ DBF_DEV_EVENT(DBF_DEBUG, device,
+ "start_IO: request %p started successful",
+ cqr);
+ break;
+ case -EBUSY:
+ DBF_DEV_EVENT(DBF_ERR, device, "%s",
+ "start_IO: device busy, retry later");
+ break;
+ case -ETIMEDOUT:
+ DBF_DEV_EVENT(DBF_ERR, device, "%s",
+ "start_IO: request timeout, retry later");
+ break;
+ case -EACCES:
+ /* -EACCES indicates that the request used only a
+ * subset of the available pathes and all these
+ * pathes are gone.
+ * Do a retry with all available pathes.
+ */
+ cqr->lpm = LPM_ANYPATH;
+ DBF_DEV_EVENT(DBF_ERR, device, "%s",
+ "start_IO: selected pathes gone,"
+ " retry on all pathes");
+ break;
+ case -ENODEV:
+ case -EIO:
+ DBF_DEV_EVENT(DBF_ERR, device, "%s",
+ "start_IO: device gone, retry");
+ break;
+ default:
+ DEV_MESSAGE(KERN_ERR, device,
+ "line %d unknown RC=%d, please report"
+ " to linux390@de.ibm.com", __LINE__, rc);
+ BUG();
+ break;
+ }
+ return rc;
+}
+
+/*
+ * Timeout function for dasd devices. This is used for different purposes
+ * 1) missing interrupt handler for normal operation
+ * 2) delayed start of request where start_IO failed with -EBUSY
+ * 3) timeout for missing state change interrupts
+ * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
+ * DASD_CQR_QUEUED for 2) and 3).
+ */
+static void
+dasd_timeout_device(unsigned long ptr)
+{
+ unsigned long flags;
+ struct dasd_device *device;
+
+ device = (struct dasd_device *) ptr;
+ spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+ /* re-activate request queue */
+ device->stopped &= ~DASD_STOPPED_PENDING;
+ spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+ dasd_schedule_bh(device);
+}
+
+/*
+ * Setup timeout for a device in jiffies.
+ */
+void
+dasd_set_timer(struct dasd_device *device, int expires)
+{
+ if (expires == 0) {
+ if (timer_pending(&device->timer))
+ del_timer(&device->timer);
+ return;
+ }
+ if (timer_pending(&device->timer)) {
+ if (mod_timer(&device->timer, jiffies + expires))
+ return;
+ }
+ device->timer.function = dasd_timeout_device;
+ device->timer.data = (unsigned long) device;
+ device->timer.expires = jiffies + expires;
+ add_timer(&device->timer);
+}
+
+/*
+ * Clear timeout for a device.
+ */
+void
+dasd_clear_timer(struct dasd_device *device)
+{
+ if (timer_pending(&device->timer))
+ del_timer(&device->timer);
+}
+
+static void
+dasd_handle_killed_request(struct ccw_device *cdev, unsigned long intparm)
+{
+ struct dasd_ccw_req *cqr;
+ struct dasd_device *device;
+
+ cqr = (struct dasd_ccw_req *) intparm;
+ if (cqr->status != DASD_CQR_IN_IO) {
+ MESSAGE(KERN_DEBUG,
+ "invalid status in handle_killed_request: "
+ "bus_id %s, status %02x",
+ cdev->dev.bus_id, cqr->status);
+ return;
+ }
+
+ device = (struct dasd_device *) cqr->device;
+ if (device == NULL ||
+ device != dasd_device_from_cdev(cdev) ||
+ strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
+ MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
+ cdev->dev.bus_id);
+ return;
+ }
+
+ /* Schedule request to be retried. */
+ cqr->status = DASD_CQR_QUEUED;
+
+ dasd_clear_timer(device);
+ dasd_schedule_bh(device);
+ dasd_put_device(device);
+}
+
+static void
+dasd_handle_state_change_pending(struct dasd_device *device)
+{
+ struct dasd_ccw_req *cqr;
+ struct list_head *l, *n;
+
+ device->stopped &= ~DASD_STOPPED_PENDING;
+
+ /* restart all 'running' IO on queue */
+ list_for_each_safe(l, n, &device->ccw_queue) {
+ cqr = list_entry(l, struct dasd_ccw_req, list);
+ if (cqr->status == DASD_CQR_IN_IO) {
+ cqr->status = DASD_CQR_QUEUED;
+ }
+ }
+ dasd_clear_timer(device);
+ dasd_schedule_bh(device);
+}
+
+/*
+ * Interrupt handler for "normal" ssch-io based dasd devices.
+ */
+void
+dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
+ struct irb *irb)
+{
+ struct dasd_ccw_req *cqr, *next;
+ struct dasd_device *device;
+ unsigned long long now;
+ int expires;
+ dasd_era_t era;
+ char mask;
+
+ if (IS_ERR(irb)) {
+ switch (PTR_ERR(irb)) {
+ case -EIO:
+ dasd_handle_killed_request(cdev, intparm);
+ break;
+ case -ETIMEDOUT:
+ printk(KERN_WARNING"%s(%s): request timed out\n",
+ __FUNCTION__, cdev->dev.bus_id);
+ //FIXME - dasd uses own timeout interface...
+ break;
+ default:
+ printk(KERN_WARNING"%s(%s): unknown error %ld\n",
+ __FUNCTION__, cdev->dev.bus_id, PTR_ERR(irb));
+ }
+ return;
+ }
+
+ now = get_clock();
+
+ DBF_EVENT(DBF_ERR, "Interrupt: bus_id %s CS/DS %04x ip %08x",
+ cdev->dev.bus_id, ((irb->scsw.cstat<<8)|irb->scsw.dstat),
+ (unsigned int) intparm);
+
+ /* first of all check for state change pending interrupt */
+ mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
+ if ((irb->scsw.dstat & mask) == mask) {
+ device = dasd_device_from_cdev(cdev);
+ if (!IS_ERR(device)) {
+ dasd_handle_state_change_pending(device);
+ dasd_put_device(device);
+ }
+ return;
+ }
+
+ cqr = (struct dasd_ccw_req *) intparm;
+
+ /* check for unsolicited interrupts */
+ if (cqr == NULL) {
+ MESSAGE(KERN_DEBUG,
+ "unsolicited interrupt received: bus_id %s",
+ cdev->dev.bus_id);
+ return;
+ }
+
+ device = (struct dasd_device *) cqr->device;
+ if (device == NULL ||
+ strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
+ MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
+ cdev->dev.bus_id);
+ return;
+ }
+
+ /* Check for clear pending */
+ if (cqr->status == DASD_CQR_CLEAR &&
+ irb->scsw.fctl & SCSW_FCTL_CLEAR_FUNC) {
+ cqr->status = DASD_CQR_QUEUED;
+ dasd_clear_timer(device);
+ dasd_schedule_bh(device);
+ return;
+ }
+
+ /* check status - the request might have been killed by dyn detach */
+ if (cqr->status != DASD_CQR_IN_IO) {
+ MESSAGE(KERN_DEBUG,
+ "invalid status: bus_id %s, status %02x",
+ cdev->dev.bus_id, cqr->status);
+ return;
+ }
+ DBF_DEV_EVENT(DBF_DEBUG, device, "Int: CS/DS 0x%04x for cqr %p",
+ ((irb->scsw.cstat << 8) | irb->scsw.dstat), cqr);
+
+ /* Find out the appropriate era_action. */
+ if (irb->scsw.fctl & SCSW_FCTL_HALT_FUNC)
+ era = dasd_era_fatal;
+ else if (irb->scsw.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
+ irb->scsw.cstat == 0 &&
+ !irb->esw.esw0.erw.cons)
+ era = dasd_era_none;
+ else if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags))
+ era = dasd_era_fatal; /* don't recover this request */
+ else if (irb->esw.esw0.erw.cons)
+ era = device->discipline->examine_error(cqr, irb);
+ else
+ era = dasd_era_recover;
+
+ DBF_DEV_EVENT(DBF_DEBUG, device, "era_code %d", era);
+ expires = 0;
+ if (era == dasd_era_none) {
+ cqr->status = DASD_CQR_DONE;
+ cqr->stopclk = now;
+ /* Start first request on queue if possible -> fast_io. */
+ if (cqr->list.next != &device->ccw_queue) {
+ next = list_entry(cqr->list.next,
+ struct dasd_ccw_req, list);
+ if ((next->status == DASD_CQR_QUEUED) &&
+ (!device->stopped)) {
+ if (device->discipline->start_IO(next) == 0)
+ expires = next->expires;
+ else
+ DEV_MESSAGE(KERN_DEBUG, device, "%s",
+ "Interrupt fastpath "
+ "failed!");
+ }
+ }
+ } else { /* error */
+ memcpy(&cqr->irb, irb, sizeof (struct irb));
+#ifdef ERP_DEBUG
+ /* dump sense data */
+ dasd_log_sense(cqr, irb);
+#endif
+ switch (era) {
+ case dasd_era_fatal:
+ cqr->status = DASD_CQR_FAILED;
+ cqr->stopclk = now;
+ break;
+ case dasd_era_recover:
+ cqr->status = DASD_CQR_ERROR;
+ break;
+ default:
+ BUG();
+ }
+ }
+ if (expires != 0)
+ dasd_set_timer(device, expires);
+ else
+ dasd_clear_timer(device);
+ dasd_schedule_bh(device);
+}
+
+/*
+ * posts the buffer_cache about a finalized request
+ */
+static inline void
+dasd_end_request(struct request *req, int uptodate)
+{
+ if (end_that_request_first(req, uptodate, req->hard_nr_sectors))
+ BUG();
+ add_disk_randomness(req->rq_disk);
+ end_that_request_last(req);
+}
+
+/*
+ * Process finished error recovery ccw.
+ */
+static inline void
+__dasd_process_erp(struct dasd_device *device, struct dasd_ccw_req *cqr)
+{
+ dasd_erp_fn_t erp_fn;
+
+ if (cqr->status == DASD_CQR_DONE)
+ DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
+ else
+ DEV_MESSAGE(KERN_ERR, device, "%s", "ERP unsuccessful");
+ erp_fn = device->discipline->erp_postaction(cqr);
+ erp_fn(cqr);
+}
+
+/*
+ * Process ccw request queue.
+ */
+static inline void
+__dasd_process_ccw_queue(struct dasd_device * device,
+ struct list_head *final_queue)
+{
+ struct list_head *l, *n;
+ struct dasd_ccw_req *cqr;
+ dasd_erp_fn_t erp_fn;
+
+restart:
+ /* Process request with final status. */
+ list_for_each_safe(l, n, &device->ccw_queue) {
+ cqr = list_entry(l, struct dasd_ccw_req, list);
+ /* Stop list processing at the first non-final request. */
+ if (cqr->status != DASD_CQR_DONE &&
+ cqr->status != DASD_CQR_FAILED &&
+ cqr->status != DASD_CQR_ERROR)
+ break;
+ /* Process requests with DASD_CQR_ERROR */
+ if (cqr->status == DASD_CQR_ERROR) {
+ if (cqr->irb.scsw.fctl & SCSW_FCTL_HALT_FUNC) {
+ cqr->status = DASD_CQR_FAILED;
+ cqr->stopclk = get_clock();
+ } else {
+ if (cqr->irb.esw.esw0.erw.cons) {
+ erp_fn = device->discipline->
+ erp_action(cqr);
+ erp_fn(cqr);
+ } else
+ dasd_default_erp_action(cqr);
+ }
+ goto restart;
+ }
+ /* Process finished ERP request. */
+ if (cqr->refers) {
+ __dasd_process_erp(device, cqr);
+ goto restart;
+ }
+
+ /* Rechain finished requests to final queue */
+ cqr->endclk = get_clock();
+ list_move_tail(&cqr->list, final_queue);
+ }
+}
+
+static void
+dasd_end_request_cb(struct dasd_ccw_req * cqr, void *data)
+{
+ struct request *req;
+ struct dasd_device *device;
+ int status;
+
+ req = (struct request *) data;
+ device = cqr->device;
+ dasd_profile_end(device, cqr, req);
+ status = cqr->device->discipline->free_cp(cqr,req);
+ spin_lock_irq(&device->request_queue_lock);
+ dasd_end_request(req, status);
+ spin_unlock_irq(&device->request_queue_lock);
+}
+
+
+/*
+ * Fetch requests from the block device queue.
+ */
+static inline void
+__dasd_process_blk_queue(struct dasd_device * device)
+{
+ request_queue_t *queue;
+ struct request *req;
+ struct dasd_ccw_req *cqr;
+ int nr_queued;
+
+ queue = device->request_queue;
+ /* No queue ? Then there is nothing to do. */
+ if (queue == NULL)
+ return;
+
+ /*
+ * We requeue request from the block device queue to the ccw
+ * queue only in two states. In state DASD_STATE_READY the
+ * partition detection is done and we need to requeue requests
+ * for that. State DASD_STATE_ONLINE is normal block device
+ * operation.
+ */
+ if (device->state != DASD_STATE_READY &&
+ device->state != DASD_STATE_ONLINE)
+ return;
+ nr_queued = 0;
+ /* Now we try to fetch requests from the request queue */
+ list_for_each_entry(cqr, &device->ccw_queue, list)
+ if (cqr->status == DASD_CQR_QUEUED)
+ nr_queued++;
+ while (!blk_queue_plugged(queue) &&
+ elv_next_request(queue) &&
+ nr_queued < DASD_CHANQ_MAX_SIZE) {
+ req = elv_next_request(queue);
+ if (test_bit(DASD_FLAG_RO, &device->flags) &&
+ rq_data_dir(req) == WRITE) {
+ DBF_DEV_EVENT(DBF_ERR, device,
+ "Rejecting write request %p",
+ req);
+ blkdev_dequeue_request(req);
+ dasd_end_request(req, 0);
+ continue;
+ }
+ if (device->stopped & DASD_STOPPED_DC_EIO) {
+ blkdev_dequeue_request(req);
+ dasd_end_request(req, 0);
+ continue;
+ }
+ cqr = device->discipline->build_cp(device, req);
+ if (IS_ERR(cqr)) {
+ if (PTR_ERR(cqr) == -ENOMEM)
+ break; /* terminate request queue loop */
+ DBF_DEV_EVENT(DBF_ERR, device,
+ "CCW creation failed (rc=%ld) "
+ "on request %p",
+ PTR_ERR(cqr), req);
+ blkdev_dequeue_request(req);
+ dasd_end_request(req, 0);
+ continue;
+ }
+ cqr->callback = dasd_end_request_cb;
+ cqr->callback_data = (void *) req;
+ cqr->status = DASD_CQR_QUEUED;
+ blkdev_dequeue_request(req);
+ list_add_tail(&cqr->list, &device->ccw_queue);
+ dasd_profile_start(device, cqr, req);
+ nr_queued++;
+ }
+}
+
+/*
+ * Take a look at the first request on the ccw queue and check
+ * if it reached its expire time. If so, terminate the IO.
+ */
+static inline void
+__dasd_check_expire(struct dasd_device * device)
+{
+ struct dasd_ccw_req *cqr;
+
+ if (list_empty(&device->ccw_queue))
+ return;
+ cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
+ if (cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) {
+ if (time_after_eq(jiffies, cqr->expires + cqr->starttime)) {
+ if (device->discipline->term_IO(cqr) != 0)
+ /* Hmpf, try again in 1/10 sec */
+ dasd_set_timer(device, 10);
+ }
+ }
+}
+
+/*
+ * Take a look at the first request on the ccw queue and check
+ * if it needs to be started.
+ */
+static inline void
+__dasd_start_head(struct dasd_device * device)
+{
+ struct dasd_ccw_req *cqr;
+ int rc;
+
+ if (list_empty(&device->ccw_queue))
+ return;
+ cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
+ if ((cqr->status == DASD_CQR_QUEUED) &&
+ (!device->stopped)) {
+ /* try to start the first I/O that can be started */
+ rc = device->discipline->start_IO(cqr);
+ if (rc == 0)
+ dasd_set_timer(device, cqr->expires);
+ else if (rc == -EACCES) {
+ dasd_schedule_bh(device);
+ } else
+ /* Hmpf, try again in 1/2 sec */
+ dasd_set_timer(device, 50);
+ }
+}
+
+/*
+ * Remove requests from the ccw queue.
+ */
+static void
+dasd_flush_ccw_queue(struct dasd_device * device, int all)
+{
+ struct list_head flush_queue;
+ struct list_head *l, *n;
+ struct dasd_ccw_req *cqr;
+
+ INIT_LIST_HEAD(&flush_queue);
+ spin_lock_irq(get_ccwdev_lock(device->cdev));
+ list_for_each_safe(l, n, &device->ccw_queue) {
+ cqr = list_entry(l, struct dasd_ccw_req, list);
+ /* Flush all request or only block device requests? */
+ if (all == 0 && cqr->callback == dasd_end_request_cb)
+ continue;
+ if (cqr->status == DASD_CQR_IN_IO)
+ device->discipline->term_IO(cqr);
+ if (cqr->status != DASD_CQR_DONE ||
+ cqr->status != DASD_CQR_FAILED) {
+ cqr->status = DASD_CQR_FAILED;
+ cqr->stopclk = get_clock();
+ }
+ /* Process finished ERP request. */
+ if (cqr->refers) {
+ __dasd_process_erp(device, cqr);
+ continue;
+ }
+ /* Rechain request on device request queue */
+ cqr->endclk = get_clock();
+ list_move_tail(&cqr->list, &flush_queue);
+ }
+ spin_unlock_irq(get_ccwdev_lock(device->cdev));
+ /* Now call the callback function of flushed requests */
+ list_for_each_safe(l, n, &flush_queue) {
+ cqr = list_entry(l, struct dasd_ccw_req, list);
+ if (cqr->callback != NULL)
+ (cqr->callback)(cqr, cqr->callback_data);
+ }
+}
+
+/*
+ * Acquire the device lock and process queues for the device.
+ */
+static void
+dasd_tasklet(struct dasd_device * device)
+{
+ struct list_head final_queue;
+ struct list_head *l, *n;
+ struct dasd_ccw_req *cqr;
+
+ atomic_set (&device->tasklet_scheduled, 0);
+ INIT_LIST_HEAD(&final_queue);
+ spin_lock_irq(get_ccwdev_lock(device->cdev));
+ /* Check expire time of first request on the ccw queue. */
+ __dasd_check_expire(device);
+ /* Finish off requests on ccw queue */
+ __dasd_process_ccw_queue(device, &final_queue);
+ spin_unlock_irq(get_ccwdev_lock(device->cdev));
+ /* Now call the callback function of requests with final status */
+ list_for_each_safe(l, n, &final_queue) {
+ cqr = list_entry(l, struct dasd_ccw_req, list);
+ list_del(&cqr->list);
+ if (cqr->callback != NULL)
+ (cqr->callback)(cqr, cqr->callback_data);
+ }
+ spin_lock_irq(&device->request_queue_lock);
+ spin_lock(get_ccwdev_lock(device->cdev));
+ /* Get new request from the block device request queue */
+ __dasd_process_blk_queue(device);
+ /* Now check if the head of the ccw queue needs to be started. */
+ __dasd_start_head(device);
+ spin_unlock(get_ccwdev_lock(device->cdev));
+ spin_unlock_irq(&device->request_queue_lock);
+ dasd_put_device(device);
+}
+
+/*
+ * Schedules a call to dasd_tasklet over the device tasklet.
+ */
+void
+dasd_schedule_bh(struct dasd_device * device)
+{
+ /* Protect against rescheduling. */
+ if (atomic_compare_and_swap (0, 1, &device->tasklet_scheduled))
+ return;
+ dasd_get_device(device);
+ tasklet_hi_schedule(&device->tasklet);
+}
+
+/*
+ * Queue a request to the head of the ccw_queue. Start the I/O if
+ * possible.
+ */
+void
+dasd_add_request_head(struct dasd_ccw_req *req)
+{
+ struct dasd_device *device;
+ unsigned long flags;
+
+ device = req->device;
+ spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+ req->status = DASD_CQR_QUEUED;
+ req->device = device;
+ list_add(&req->list, &device->ccw_queue);
+ /* let the bh start the request to keep them in order */
+ dasd_schedule_bh(device);
+ spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+}
+
+/*
+ * Queue a request to the tail of the ccw_queue. Start the I/O if
+ * possible.
+ */
+void
+dasd_add_request_tail(struct dasd_ccw_req *req)
+{
+ struct dasd_device *device;
+ unsigned long flags;
+
+ device = req->device;
+ spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+ req->status = DASD_CQR_QUEUED;
+ req->device = device;
+ list_add_tail(&req->list, &device->ccw_queue);
+ /* let the bh start the request to keep them in order */
+ dasd_schedule_bh(device);
+ spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+}
+
+/*
+ * Wakeup callback.
+ */
+static void
+dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
+{
+ wake_up((wait_queue_head_t *) data);
+}
+
+static inline int
+_wait_for_wakeup(struct dasd_ccw_req *cqr)
+{
+ struct dasd_device *device;
+ int rc;
+
+ device = cqr->device;
+ spin_lock_irq(get_ccwdev_lock(device->cdev));
+ rc = cqr->status == DASD_CQR_DONE || cqr->status == DASD_CQR_FAILED;
+ spin_unlock_irq(get_ccwdev_lock(device->cdev));
+ return rc;
+}
+
+/*
+ * Attempts to start a special ccw queue and waits for its completion.
+ */
+int
+dasd_sleep_on(struct dasd_ccw_req * cqr)
+{
+ wait_queue_head_t wait_q;
+ struct dasd_device *device;
+ int rc;
+
+ device = cqr->device;
+ spin_lock_irq(get_ccwdev_lock(device->cdev));
+
+ init_waitqueue_head (&wait_q);
+ cqr->callback = dasd_wakeup_cb;
+ cqr->callback_data = (void *) &wait_q;
+ cqr->status = DASD_CQR_QUEUED;
+ list_add_tail(&cqr->list, &device->ccw_queue);
+
+ /* let the bh start the request to keep them in order */
+ dasd_schedule_bh(device);
+
+ spin_unlock_irq(get_ccwdev_lock(device->cdev));
+
+ wait_event(wait_q, _wait_for_wakeup(cqr));
+
+ /* Request status is either done or failed. */
+ rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
+ return rc;
+}
+
+/*
+ * Attempts to start a special ccw queue and wait interruptible
+ * for its completion.
+ */
+int
+dasd_sleep_on_interruptible(struct dasd_ccw_req * cqr)
+{
+ wait_queue_head_t wait_q;
+ struct dasd_device *device;
+ int rc, finished;
+
+ device = cqr->device;
+ spin_lock_irq(get_ccwdev_lock(device->cdev));
+
+ init_waitqueue_head (&wait_q);
+ cqr->callback = dasd_wakeup_cb;
+ cqr->callback_data = (void *) &wait_q;
+ cqr->status = DASD_CQR_QUEUED;
+ list_add_tail(&cqr->list, &device->ccw_queue);
+
+ /* let the bh start the request to keep them in order */
+ dasd_schedule_bh(device);
+ spin_unlock_irq(get_ccwdev_lock(device->cdev));
+
+ finished = 0;
+ while (!finished) {
+ rc = wait_event_interruptible(wait_q, _wait_for_wakeup(cqr));
+ if (rc != -ERESTARTSYS) {
+ /* Request status is either done or failed. */
+ rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
+ break;
+ }
+ spin_lock_irq(get_ccwdev_lock(device->cdev));
+ if (cqr->status == DASD_CQR_IN_IO &&
+ device->discipline->term_IO(cqr) == 0) {
+ list_del(&cqr->list);
+ finished = 1;
+ }
+ spin_unlock_irq(get_ccwdev_lock(device->cdev));
+ }
+ return rc;
+}
+
+/*
+ * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
+ * for eckd devices) the currently running request has to be terminated
+ * and be put back to status queued, before the special request is added
+ * to the head of the queue. Then the special request is waited on normally.
+ */
+static inline int
+_dasd_term_running_cqr(struct dasd_device *device)
+{
+ struct dasd_ccw_req *cqr;
+ int rc;
+
+ if (list_empty(&device->ccw_queue))
+ return 0;
+ cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
+ rc = device->discipline->term_IO(cqr);
+ if (rc == 0) {
+ /* termination successful */
+ cqr->status = DASD_CQR_QUEUED;
+ cqr->startclk = cqr->stopclk = 0;
+ cqr->starttime = 0;
+ }
+ return rc;
+}
+
+int
+dasd_sleep_on_immediatly(struct dasd_ccw_req * cqr)
+{
+ wait_queue_head_t wait_q;
+ struct dasd_device *device;
+ int rc;
+
+ device = cqr->device;
+ spin_lock_irq(get_ccwdev_lock(device->cdev));
+ rc = _dasd_term_running_cqr(device);
+ if (rc) {
+ spin_unlock_irq(get_ccwdev_lock(device->cdev));
+ return rc;
+ }
+
+ init_waitqueue_head (&wait_q);
+ cqr->callback = dasd_wakeup_cb;
+ cqr->callback_data = (void *) &wait_q;
+ cqr->status = DASD_CQR_QUEUED;
+ list_add(&cqr->list, &device->ccw_queue);
+
+ /* let the bh start the request to keep them in order */
+ dasd_schedule_bh(device);
+
+ spin_unlock_irq(get_ccwdev_lock(device->cdev));
+
+ wait_event(wait_q, _wait_for_wakeup(cqr));
+
+ /* Request status is either done or failed. */
+ rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
+ return rc;
+}
+
+/*
+ * Cancels a request that was started with dasd_sleep_on_req.
+ * This is useful to timeout requests. The request will be
+ * terminated if it is currently in i/o.
+ * Returns 1 if the request has been terminated.
+ */
+int
+dasd_cancel_req(struct dasd_ccw_req *cqr)
+{
+ struct dasd_device *device = cqr->device;
+ unsigned long flags;
+ int rc;
+
+ rc = 0;
+ spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+ switch (cqr->status) {
+ case DASD_CQR_QUEUED:
+ /* request was not started - just set to failed */
+ cqr->status = DASD_CQR_FAILED;
+ break;
+ case DASD_CQR_IN_IO:
+ /* request in IO - terminate IO and release again */
+ if (device->discipline->term_IO(cqr) != 0)
+ /* what to do if unable to terminate ??????
+ e.g. not _IN_IO */
+ cqr->status = DASD_CQR_FAILED;
+ cqr->stopclk = get_clock();
+ rc = 1;
+ break;
+ case DASD_CQR_DONE:
+ case DASD_CQR_FAILED:
+ /* already finished - do nothing */
+ break;
+ default:
+ DEV_MESSAGE(KERN_ALERT, device,
+ "invalid status %02x in request",
+ cqr->status);
+ BUG();
+
+ }
+ spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+ dasd_schedule_bh(device);
+ return rc;
+}
+
+/*
+ * SECTION: Block device operations (request queue, partitions, open, release).
+ */
+
+/*
+ * Dasd request queue function. Called from ll_rw_blk.c
+ */
+static void
+do_dasd_request(request_queue_t * queue)
+{
+ struct dasd_device *device;
+
+ device = (struct dasd_device *) queue->queuedata;
+ spin_lock(get_ccwdev_lock(device->cdev));
+ /* Get new request from the block device request queue */
+ __dasd_process_blk_queue(device);
+ /* Now check if the head of the ccw queue needs to be started. */
+ __dasd_start_head(device);
+ spin_unlock(get_ccwdev_lock(device->cdev));
+}
+
+/*
+ * Allocate and initialize request queue and default I/O scheduler.
+ */
+static int
+dasd_alloc_queue(struct dasd_device * device)
+{
+ int rc;
+
+ device->request_queue = blk_init_queue(do_dasd_request,
+ &device->request_queue_lock);
+ if (device->request_queue == NULL)
+ return -ENOMEM;
+
+ device->request_queue->queuedata = device;
+
+ elevator_exit(device->request_queue->elevator);
+ rc = elevator_init(device->request_queue, "deadline");
+ if (rc) {
+ blk_cleanup_queue(device->request_queue);
+ return rc;
+ }
+ return 0;
+}
+
+/*
+ * Allocate and initialize request queue.
+ */
+static void
+dasd_setup_queue(struct dasd_device * device)
+{
+ int max;
+
+ blk_queue_hardsect_size(device->request_queue, device->bp_block);
+ max = device->discipline->max_blocks << device->s2b_shift;
+ blk_queue_max_sectors(device->request_queue, max);
+ blk_queue_max_phys_segments(device->request_queue, -1L);
+ blk_queue_max_hw_segments(device->request_queue, -1L);
+ blk_queue_max_segment_size(device->request_queue, -1L);
+ blk_queue_segment_boundary(device->request_queue, -1L);
+}
+
+/*
+ * Deactivate and free request queue.
+ */
+static void
+dasd_free_queue(struct dasd_device * device)
+{
+ if (device->request_queue) {
+ blk_cleanup_queue(device->request_queue);
+ device->request_queue = NULL;
+ }
+}
+
+/*
+ * Flush request on the request queue.
+ */
+static void
+dasd_flush_request_queue(struct dasd_device * device)
+{
+ struct request *req;
+
+ if (!device->request_queue)
+ return;
+
+ spin_lock_irq(&device->request_queue_lock);
+ while (!list_empty(&device->request_queue->queue_head)) {
+ req = elv_next_request(device->request_queue);
+ if (req == NULL)
+ break;
+ dasd_end_request(req, 0);
+ blkdev_dequeue_request(req);
+ }
+ spin_unlock_irq(&device->request_queue_lock);
+}
+
+static int
+dasd_open(struct inode *inp, struct file *filp)
+{
+ struct gendisk *disk = inp->i_bdev->bd_disk;
+ struct dasd_device *device = disk->private_data;
+ int rc;
+
+ atomic_inc(&device->open_count);
+ if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
+ rc = -ENODEV;
+ goto unlock;
+ }
+
+ if (!try_module_get(device->discipline->owner)) {
+ rc = -EINVAL;
+ goto unlock;
+ }
+
+ if (dasd_probeonly) {
+ DEV_MESSAGE(KERN_INFO, device, "%s",
+ "No access to device due to probeonly mode");
+ rc = -EPERM;
+ goto out;
+ }
+
+ if (device->state < DASD_STATE_BASIC) {
+ DBF_DEV_EVENT(DBF_ERR, device, " %s",
+ " Cannot open unrecognized device");
+ rc = -ENODEV;
+ goto out;
+ }
+
+ return 0;
+
+out:
+ module_put(device->discipline->owner);
+unlock:
+ atomic_dec(&device->open_count);
+ return rc;
+}
+
+static int
+dasd_release(struct inode *inp, struct file *filp)
+{
+ struct gendisk *disk = inp->i_bdev->bd_disk;
+ struct dasd_device *device = disk->private_data;
+
+ atomic_dec(&device->open_count);
+ module_put(device->discipline->owner);
+ return 0;
+}
+
+struct block_device_operations
+dasd_device_operations = {
+ .owner = THIS_MODULE,
+ .open = dasd_open,
+ .release = dasd_release,
+ .ioctl = dasd_ioctl,
+};
+
+
+static void
+dasd_exit(void)
+{
+#ifdef CONFIG_PROC_FS
+ dasd_proc_exit();
+#endif
+ dasd_ioctl_exit();
+ dasd_gendisk_exit();
+ dasd_devmap_exit();
+ devfs_remove("dasd");
+ if (dasd_debug_area != NULL) {
+ debug_unregister(dasd_debug_area);
+ dasd_debug_area = NULL;
+ }
+}
+
+/*
+ * SECTION: common functions for ccw_driver use
+ */
+
+/* initial attempt at a probe function. this can be simplified once
+ * the other detection code is gone */
+int
+dasd_generic_probe (struct ccw_device *cdev,
+ struct dasd_discipline *discipline)
+{
+ int ret;
+
+ ret = dasd_add_sysfs_files(cdev);
+ if (ret) {
+ printk(KERN_WARNING
+ "dasd_generic_probe: could not add sysfs entries "
+ "for %s\n", cdev->dev.bus_id);
+ }
+
+ cdev->handler = &dasd_int_handler;
+
+ return ret;
+}
+
+/* this will one day be called from a global not_oper handler.
+ * It is also used by driver_unregister during module unload */
+void
+dasd_generic_remove (struct ccw_device *cdev)
+{
+ struct dasd_device *device;
+
+ dasd_remove_sysfs_files(cdev);
+ device = dasd_device_from_cdev(cdev);
+ if (IS_ERR(device))
+ return;
+ if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
+ /* Already doing offline processing */
+ dasd_put_device(device);
+ return;
+ }
+ /*
+ * This device is removed unconditionally. Set offline
+ * flag to prevent dasd_open from opening it while it is
+ * no quite down yet.
+ */
+ dasd_set_target_state(device, DASD_STATE_NEW);
+ /* dasd_delete_device destroys the device reference. */
+ dasd_delete_device(device);
+}
+
+/* activate a device. This is called from dasd_{eckd,fba}_probe() when either
+ * the device is detected for the first time and is supposed to be used
+ * or the user has started activation through sysfs */
+int
+dasd_generic_set_online (struct ccw_device *cdev,
+ struct dasd_discipline *discipline)
+
+{
+ struct dasd_device *device;
+ int rc;
+
+ device = dasd_create_device(cdev);
+ if (IS_ERR(device))
+ return PTR_ERR(device);
+
+ if (test_bit(DASD_FLAG_USE_DIAG, &device->flags)) {
+ if (!dasd_diag_discipline_pointer) {
+ printk (KERN_WARNING
+ "dasd_generic couldn't online device %s "
+ "- discipline DIAG not available\n",
+ cdev->dev.bus_id);
+ dasd_delete_device(device);
+ return -ENODEV;
+ }
+ discipline = dasd_diag_discipline_pointer;
+ }
+ device->discipline = discipline;
+
+ rc = discipline->check_device(device);
+ if (rc) {
+ printk (KERN_WARNING
+ "dasd_generic couldn't online device %s "
+ "with discipline %s rc=%i\n",
+ cdev->dev.bus_id, discipline->name, rc);
+ dasd_delete_device(device);
+ return rc;
+ }
+
+ dasd_set_target_state(device, DASD_STATE_ONLINE);
+ if (device->state <= DASD_STATE_KNOWN) {
+ printk (KERN_WARNING
+ "dasd_generic discipline not found for %s\n",
+ cdev->dev.bus_id);
+ rc = -ENODEV;
+ dasd_set_target_state(device, DASD_STATE_NEW);
+ dasd_delete_device(device);
+ } else
+ pr_debug("dasd_generic device %s found\n",
+ cdev->dev.bus_id);
+
+ /* FIXME: we have to wait for the root device but we don't want
+ * to wait for each single device but for all at once. */
+ wait_event(dasd_init_waitq, _wait_for_device(device));
+
+ dasd_put_device(device);
+
+ return rc;
+}
+
+int
+dasd_generic_set_offline (struct ccw_device *cdev)
+{
+ struct dasd_device *device;
+ int max_count;
+
+ device = dasd_device_from_cdev(cdev);
+ if (IS_ERR(device))
+ return PTR_ERR(device);
+ if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
+ /* Already doing offline processing */
+ dasd_put_device(device);
+ return 0;
+ }
+ /*
+ * We must make sure that this device is currently not in use.
+ * The open_count is increased for every opener, that includes
+ * the blkdev_get in dasd_scan_partitions. We are only interested
+ * in the other openers.
+ */
+ max_count = device->bdev ? 0 : -1;
+ if (atomic_read(&device->open_count) > max_count) {
+ printk (KERN_WARNING "Can't offline dasd device with open"
+ " count = %i.\n",
+ atomic_read(&device->open_count));
+ clear_bit(DASD_FLAG_OFFLINE, &device->flags);
+ dasd_put_device(device);
+ return -EBUSY;
+ }
+ dasd_set_target_state(device, DASD_STATE_NEW);
+ /* dasd_delete_device destroys the device reference. */
+ dasd_delete_device(device);
+
+ return 0;
+}
+
+int
+dasd_generic_notify(struct ccw_device *cdev, int event)
+{
+ struct dasd_device *device;
+ struct dasd_ccw_req *cqr;
+ unsigned long flags;
+ int ret;
+
+ device = dasd_device_from_cdev(cdev);
+ if (IS_ERR(device))
+ return 0;
+ spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
+ ret = 0;
+ switch (event) {
+ case CIO_GONE:
+ case CIO_NO_PATH:
+ if (device->state < DASD_STATE_BASIC)
+ break;
+ /* Device is active. We want to keep it. */
+ if (test_bit(DASD_FLAG_DSC_ERROR, &device->flags)) {
+ list_for_each_entry(cqr, &device->ccw_queue, list)
+ if (cqr->status == DASD_CQR_IN_IO)
+ cqr->status = DASD_CQR_FAILED;
+ device->stopped |= DASD_STOPPED_DC_EIO;
+ dasd_schedule_bh(device);
+ } else {
+ list_for_each_entry(cqr, &device->ccw_queue, list)
+ if (cqr->status == DASD_CQR_IN_IO) {
+ cqr->status = DASD_CQR_QUEUED;
+ cqr->retries++;
+ }
+ device->stopped |= DASD_STOPPED_DC_WAIT;
+ dasd_set_timer(device, 0);
+ }
+ ret = 1;
+ break;
+ case CIO_OPER:
+ /* FIXME: add a sanity check. */
+ device->stopped &= ~(DASD_STOPPED_DC_WAIT|DASD_STOPPED_DC_EIO);
+ dasd_schedule_bh(device);
+ ret = 1;
+ break;
+ }
+ spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
+ dasd_put_device(device);
+ return ret;
+}
+
+/*
+ * Automatically online either all dasd devices (dasd_autodetect) or
+ * all devices specified with dasd= parameters.
+ */
+void
+dasd_generic_auto_online (struct ccw_driver *dasd_discipline_driver)
+{
+ struct device_driver *drv;
+ struct device *d, *dev;
+ struct ccw_device *cdev;
+
+ drv = get_driver(&dasd_discipline_driver->driver);
+ down_read(&drv->bus->subsys.rwsem);
+ dev = NULL;
+ list_for_each_entry(d, &drv->devices, driver_list) {
+ dev = get_device(d);
+ if (!dev)
+ continue;
+ cdev = to_ccwdev(dev);
+ if (dasd_autodetect || dasd_busid_known(cdev->dev.bus_id) == 0)
+ ccw_device_set_online(cdev);
+ put_device(dev);
+ }
+ up_read(&drv->bus->subsys.rwsem);
+ put_driver(drv);
+}
+
+static int __init
+dasd_init(void)
+{
+ int rc;
+
+ init_waitqueue_head(&dasd_init_waitq);
+
+ /* register 'common' DASD debug area, used for all DBF_XXX calls */
+ dasd_debug_area = debug_register("dasd", 0, 2, 8 * sizeof (long));
+ if (dasd_debug_area == NULL) {
+ rc = -ENOMEM;
+ goto failed;
+ }
+ debug_register_view(dasd_debug_area, &debug_sprintf_view);
+ debug_set_level(dasd_debug_area, DBF_EMERG);
+
+ DBF_EVENT(DBF_EMERG, "%s", "debug area created");
+
+ dasd_diag_discipline_pointer = NULL;
+
+ rc = devfs_mk_dir("dasd");
+ if (rc)
+ goto failed;
+ rc = dasd_devmap_init();
+ if (rc)
+ goto failed;
+ rc = dasd_gendisk_init();
+ if (rc)
+ goto failed;
+ rc = dasd_parse();
+ if (rc)
+ goto failed;
+ rc = dasd_ioctl_init();
+ if (rc)
+ goto failed;
+#ifdef CONFIG_PROC_FS
+ rc = dasd_proc_init();
+ if (rc)
+ goto failed;
+#endif
+
+ return 0;
+failed:
+ MESSAGE(KERN_INFO, "%s", "initialization not performed due to errors");
+ dasd_exit();
+ return rc;
+}
+
+module_init(dasd_init);
+module_exit(dasd_exit);
+
+EXPORT_SYMBOL(dasd_debug_area);
+EXPORT_SYMBOL(dasd_diag_discipline_pointer);
+
+EXPORT_SYMBOL(dasd_add_request_head);
+EXPORT_SYMBOL(dasd_add_request_tail);
+EXPORT_SYMBOL(dasd_cancel_req);
+EXPORT_SYMBOL(dasd_clear_timer);
+EXPORT_SYMBOL(dasd_enable_device);
+EXPORT_SYMBOL(dasd_int_handler);
+EXPORT_SYMBOL(dasd_kfree_request);
+EXPORT_SYMBOL(dasd_kick_device);
+EXPORT_SYMBOL(dasd_kmalloc_request);
+EXPORT_SYMBOL(dasd_schedule_bh);
+EXPORT_SYMBOL(dasd_set_target_state);
+EXPORT_SYMBOL(dasd_set_timer);
+EXPORT_SYMBOL(dasd_sfree_request);
+EXPORT_SYMBOL(dasd_sleep_on);
+EXPORT_SYMBOL(dasd_sleep_on_immediatly);
+EXPORT_SYMBOL(dasd_sleep_on_interruptible);
+EXPORT_SYMBOL(dasd_smalloc_request);
+EXPORT_SYMBOL(dasd_start_IO);
+EXPORT_SYMBOL(dasd_term_IO);
+
+EXPORT_SYMBOL_GPL(dasd_generic_probe);
+EXPORT_SYMBOL_GPL(dasd_generic_remove);
+EXPORT_SYMBOL_GPL(dasd_generic_notify);
+EXPORT_SYMBOL_GPL(dasd_generic_set_online);
+EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
+EXPORT_SYMBOL_GPL(dasd_generic_auto_online);
+
+/*
+ * Overrides for Emacs so that we follow Linus's tabbing style.
+ * Emacs will notice this stuff at the end of the file and automatically
+ * adjust the settings for this buffer only. This must remain at the end
+ * of the file.
+ * ---------------------------------------------------------------------------
+ * Local variables:
+ * c-indent-level: 4
+ * c-brace-imaginary-offset: 0
+ * c-brace-offset: -4
+ * c-argdecl-indent: 4
+ * c-label-offset: -4
+ * c-continued-statement-offset: 4
+ * c-continued-brace-offset: 0
+ * indent-tabs-mode: 1
+ * tab-width: 8
+ * End:
+ */