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kernel-fxtec-pro1x/drivers/s390/block/dasd.c
Stefan Haberland aade6c0dfb [S390] dasd: prevent IO error during reserve/release loop 
The termination of running CQR caused by reserve/release operations
may lead to an IO error if reserve/release is done in a tight loop.
Prevent this by increasing the retry counter after termination.

Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-05-10 17:13:42 +02:00

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/*
* 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>
* Copyright IBM Corp. 1999, 2009
*/
#define KMSG_COMPONENT "dasd"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/kernel_stat.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 <linux/hdreg.h>
#include <linux/async.h>
#include <linux/mutex.h>
#include <asm/ccwdev.h>
#include <asm/ebcdic.h>
#include <asm/idals.h>
#include <asm/itcw.h>
#include <asm/diag.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
#define DASD_SLEEPON_START_TAG (void *) 1
#define DASD_SLEEPON_END_TAG (void *) 2
/*
* SECTION: exported variables of dasd.c
*/
debug_info_t *dasd_debug_area;
struct dasd_discipline *dasd_diag_discipline_pointer;
void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
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_LICENSE("GPL");
/*
* SECTION: prototypes for static functions of dasd.c
*/
static int dasd_alloc_queue(struct dasd_block *);
static void dasd_setup_queue(struct dasd_block *);
static void dasd_free_queue(struct dasd_block *);
static void dasd_flush_request_queue(struct dasd_block *);
static int dasd_flush_block_queue(struct dasd_block *);
static void dasd_device_tasklet(struct dasd_device *);
static void dasd_block_tasklet(struct dasd_block *);
static void do_kick_device(struct work_struct *);
static void do_restore_device(struct work_struct *);
static void do_reload_device(struct work_struct *);
static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
static void dasd_device_timeout(unsigned long);
static void dasd_block_timeout(unsigned long);
static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
/*
* SECTION: Operations on the device structure.
*/
static wait_queue_head_t dasd_init_waitq;
static wait_queue_head_t dasd_flush_wq;
static wait_queue_head_t generic_waitq;
/*
* Allocate memory for a new device structure.
*/
struct dasd_device *dasd_alloc_device(void)
{
struct dasd_device *device;
device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
if (!device)
return ERR_PTR(-ENOMEM);
/* Get two pages for normal block device operations. */
device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
if (!device->ccw_mem) {
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) {
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);
atomic_set(&device->tasklet_scheduled, 0);
tasklet_init(&device->tasklet,
(void (*)(unsigned long)) dasd_device_tasklet,
(unsigned long) device);
INIT_LIST_HEAD(&device->ccw_queue);
init_timer(&device->timer);
device->timer.function = dasd_device_timeout;
device->timer.data = (unsigned long) device;
INIT_WORK(&device->kick_work, do_kick_device);
INIT_WORK(&device->restore_device, do_restore_device);
INIT_WORK(&device->reload_device, do_reload_device);
device->state = DASD_STATE_NEW;
device->target = DASD_STATE_NEW;
mutex_init(&device->state_mutex);
return device;
}
/*
* Free memory of a device structure.
*/
void dasd_free_device(struct dasd_device *device)
{
kfree(device->private);
free_page((unsigned long) device->erp_mem);
free_pages((unsigned long) device->ccw_mem, 1);
kfree(device);
}
/*
* Allocate memory for a new device structure.
*/
struct dasd_block *dasd_alloc_block(void)
{
struct dasd_block *block;
block = kzalloc(sizeof(*block), GFP_ATOMIC);
if (!block)
return ERR_PTR(-ENOMEM);
/* open_count = 0 means device online but not in use */
atomic_set(&block->open_count, -1);
spin_lock_init(&block->request_queue_lock);
atomic_set(&block->tasklet_scheduled, 0);
tasklet_init(&block->tasklet,
(void (*)(unsigned long)) dasd_block_tasklet,
(unsigned long) block);
INIT_LIST_HEAD(&block->ccw_queue);
spin_lock_init(&block->queue_lock);
init_timer(&block->timer);
block->timer.function = dasd_block_timeout;
block->timer.data = (unsigned long) block;
return block;
}
/*
* Free memory of a device structure.
*/
void dasd_free_block(struct dasd_block *block)
{
kfree(block);
}
/*
* Make a new device known to the system.
*/
static 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);
if (device->block) {
rc = dasd_alloc_queue(device->block);
if (rc) {
dasd_put_device(device);
return rc;
}
}
device->state = DASD_STATE_KNOWN;
return 0;
}
/*
* Let the system forget about a device.
*/
static int dasd_state_known_to_new(struct dasd_device *device)
{
/* Disable extended error reporting for this device. */
dasd_eer_disable(device);
/* Forget the discipline information. */
if (device->discipline) {
if (device->discipline->uncheck_device)
device->discipline->uncheck_device(device);
module_put(device->discipline->owner);
}
device->discipline = NULL;
if (device->base_discipline)
module_put(device->base_discipline->owner);
device->base_discipline = NULL;
device->state = DASD_STATE_NEW;
if (device->block)
dasd_free_queue(device->block);
/* Give up reference we took in dasd_state_new_to_known. */
dasd_put_device(device);
return 0;
}
/*
* Request the irq line for the device.
*/
static int dasd_state_known_to_basic(struct dasd_device *device)
{
int rc;
/* Allocate and register gendisk structure. */
if (device->block) {
rc = dasd_gendisk_alloc(device->block);
if (rc)
return rc;
}
/* register 'device' debug area, used for all DBF_DEV_XXX calls */
device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
8 * sizeof(long));
debug_register_view(device->debug_area, &debug_sprintf_view);
debug_set_level(device->debug_area, DBF_WARNING);
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 int dasd_state_basic_to_known(struct dasd_device *device)
{
int rc;
if (device->block) {
dasd_gendisk_free(device->block);
dasd_block_clear_timer(device->block);
}
rc = dasd_flush_device_queue(device);
if (rc)
return rc;
dasd_device_clear_timer(device);
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;
return 0;
}
/*
* 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) the block
* device is setup.
* In case the analysis returns an error, the device setup is stopped
* (a fake disk was already added to allow formatting).
*/
static int dasd_state_basic_to_ready(struct dasd_device *device)
{
int rc;
struct dasd_block *block;
rc = 0;
block = device->block;
/* make disk known with correct capacity */
if (block) {
if (block->base->discipline->do_analysis != NULL)
rc = block->base->discipline->do_analysis(block);
if (rc) {
if (rc != -EAGAIN)
device->state = DASD_STATE_UNFMT;
return rc;
}
dasd_setup_queue(block);
set_capacity(block->gdp,
block->blocks << block->s2b_shift);
device->state = DASD_STATE_READY;
rc = dasd_scan_partitions(block);
if (rc)
device->state = DASD_STATE_BASIC;
} else {
device->state = DASD_STATE_READY;
}
return rc;
}
/*
* 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 int dasd_state_ready_to_basic(struct dasd_device *device)
{
int rc;
device->state = DASD_STATE_BASIC;
if (device->block) {
struct dasd_block *block = device->block;
rc = dasd_flush_block_queue(block);
if (rc) {
device->state = DASD_STATE_READY;
return rc;
}
dasd_flush_request_queue(block);
dasd_destroy_partitions(block);
block->blocks = 0;
block->bp_block = 0;
block->s2b_shift = 0;
}
return 0;
}
/*
* Back to basic.
*/
static int dasd_state_unfmt_to_basic(struct dasd_device *device)
{
device->state = DASD_STATE_BASIC;
return 0;
}
/*
* 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 int
dasd_state_ready_to_online(struct dasd_device * device)
{
int rc;
struct gendisk *disk;
struct disk_part_iter piter;
struct hd_struct *part;
if (device->discipline->ready_to_online) {
rc = device->discipline->ready_to_online(device);
if (rc)
return rc;
}
device->state = DASD_STATE_ONLINE;
if (device->block) {
dasd_schedule_block_bh(device->block);
if ((device->features & DASD_FEATURE_USERAW)) {
disk = device->block->gdp;
kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
return 0;
}
disk = device->block->bdev->bd_disk;
disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
while ((part = disk_part_iter_next(&piter)))
kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
disk_part_iter_exit(&piter);
}
return 0;
}
/*
* Stop the requeueing of requests again.
*/
static int dasd_state_online_to_ready(struct dasd_device *device)
{
int rc;
struct gendisk *disk;
struct disk_part_iter piter;
struct hd_struct *part;
if (device->discipline->online_to_ready) {
rc = device->discipline->online_to_ready(device);
if (rc)
return rc;
}
device->state = DASD_STATE_READY;
if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
disk = device->block->bdev->bd_disk;
disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
while ((part = disk_part_iter_next(&piter)))
kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
disk_part_iter_exit(&piter);
}
return 0;
}
/*
* Device startup state changes.
*/
static 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_UNFMT &&
device->target > DASD_STATE_UNFMT)
rc = -EPERM;
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 int dasd_decrease_state(struct dasd_device *device)
{
int rc;
rc = 0;
if (device->state == DASD_STATE_ONLINE &&
device->target <= DASD_STATE_READY)
rc = dasd_state_online_to_ready(device);
if (!rc &&
device->state == DASD_STATE_READY &&
device->target <= DASD_STATE_BASIC)
rc = dasd_state_ready_to_basic(device);
if (!rc &&
device->state == DASD_STATE_UNFMT &&
device->target <= DASD_STATE_BASIC)
rc = dasd_state_unfmt_to_basic(device);
if (!rc &&
device->state == DASD_STATE_BASIC &&
device->target <= DASD_STATE_KNOWN)
rc = dasd_state_basic_to_known(device);
if (!rc &&
device->state == DASD_STATE_KNOWN &&
device->target <= DASD_STATE_NEW)
rc = dasd_state_known_to_new(device);
return rc;
}
/*
* 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 == -EAGAIN)
return;
if (rc)
device->target = device->state;
if (device->state == device->target)
wake_up(&dasd_init_waitq);
/* let user-space know that the device status changed */
kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
}
/*
* 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(struct work_struct *work)
{
struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
mutex_lock(&device->state_mutex);
dasd_change_state(device);
mutex_unlock(&device->state_mutex);
dasd_schedule_device_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);
}
/*
* dasd_reload_device will schedule a call do do_reload_device to the kernel
* event daemon.
*/
static void do_reload_device(struct work_struct *work)
{
struct dasd_device *device = container_of(work, struct dasd_device,
reload_device);
device->discipline->reload(device);
dasd_put_device(device);
}
void dasd_reload_device(struct dasd_device *device)
{
dasd_get_device(device);
/* queue call to dasd_reload_device to the kernel event daemon. */
schedule_work(&device->reload_device);
}
EXPORT_SYMBOL(dasd_reload_device);
/*
* dasd_restore_device will schedule a call do do_restore_device to the kernel
* event daemon.
*/
static void do_restore_device(struct work_struct *work)
{
struct dasd_device *device = container_of(work, struct dasd_device,
restore_device);
device->cdev->drv->restore(device->cdev);
dasd_put_device(device);
}
void dasd_restore_device(struct dasd_device *device)
{
dasd_get_device(device);
/* queue call to dasd_restore_device to the kernel event daemon. */
schedule_work(&device->restore_device);
}
/*
* Set the target state for a device and starts the state change.
*/
void dasd_set_target_state(struct dasd_device *device, int target)
{
dasd_get_device(device);
mutex_lock(&device->state_mutex);
/* 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);
mutex_unlock(&device->state_mutex);
dasd_put_device(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, block) \
{ \
int index; \
for (index = 0; index < 31 && value >> (2+index); index++); \
dasd_global_profile.counter[index]++; \
block->profile.counter[index]++; \
}
/*
* Add profiling information for cqr before execution.
*/
static void dasd_profile_start(struct dasd_block *block,
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, &block->ccw_queue)
if (++counter >= 31)
break;
dasd_global_profile.dasd_io_nr_req[counter]++;
block->profile.dasd_io_nr_req[counter]++;
}
/*
* Add profiling information for cqr after execution.
*/
static void dasd_profile_end(struct dasd_block *block,
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 = blk_rq_sectors(req);
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 (!block->profile.dasd_io_reqs)
memset(&block->profile, 0,
sizeof(struct dasd_profile_info_t));
block->profile.dasd_io_reqs++;
block->profile.dasd_io_sects += sectors;
dasd_profile_counter(sectors, dasd_io_secs, block);
dasd_profile_counter(tottime, dasd_io_times, block);
dasd_profile_counter(tottimeps, dasd_io_timps, block);
dasd_profile_counter(strtime, dasd_io_time1, block);
dasd_profile_counter(irqtime, dasd_io_time2, block);
dasd_profile_counter(irqtime / sectors, dasd_io_time2ps, block);
dasd_profile_counter(endtime, dasd_io_time3, block);
}
#else
#define dasd_profile_start(block, cqr, req) do {} while (0)
#define dasd_profile_end(block, 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(int magic, int cplength,
int datasize,
struct dasd_device *device)
{
struct dasd_ccw_req *cqr;
/* Sanity checks */
BUG_ON(datasize > PAGE_SIZE ||
(cplength*sizeof(struct ccw1)) > PAGE_SIZE);
cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
if (cqr == NULL)
return ERR_PTR(-ENOMEM);
cqr->cpaddr = NULL;
if (cplength > 0) {
cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
GFP_ATOMIC | GFP_DMA);
if (cqr->cpaddr == NULL) {
kfree(cqr);
return ERR_PTR(-ENOMEM);
}
}
cqr->data = NULL;
if (datasize > 0) {
cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
if (cqr->data == NULL) {
kfree(cqr->cpaddr);
kfree(cqr);
return ERR_PTR(-ENOMEM);
}
}
cqr->magic = magic;
set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
dasd_get_device(device);
return cqr;
}
struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength,
int datasize,
struct dasd_device *device)
{
unsigned long flags;
struct dasd_ccw_req *cqr;
char *data;
int size;
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);
}
cqr->magic = magic;
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_64BIT
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
kfree(cqr->cpaddr);
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->startdev;
if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
DBF_DEV_EVENT(DBF_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;
char errorstring[ERRORLENGTH];
/* Check the cqr */
rc = dasd_check_cqr(cqr);
if (rc)
return rc;
retries = 0;
device = (struct dasd_device *) cqr->startdev;
while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
rc = ccw_device_clear(device->cdev, (long) cqr);
switch (rc) {
case 0: /* termination successful */
cqr->status = DASD_CQR_CLEAR_PENDING;
cqr->stopclk = get_clock();
cqr->starttime = 0;
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:
/* internal error 10 - unknown rc*/
snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
dev_err(&device->cdev->dev, "An error occurred in the "
"DASD device driver, reason=%s\n", errorstring);
BUG();
break;
}
retries++;
}
dasd_schedule_device_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;
char errorstring[ERRORLENGTH];
/* Check the cqr */
rc = dasd_check_cqr(cqr);
if (rc) {
cqr->intrc = rc;
return rc;
}
device = (struct dasd_device *) cqr->startdev;
if (((cqr->block &&
test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
!test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
"because of stolen lock", cqr);
cqr->status = DASD_CQR_ERROR;
cqr->intrc = -EPERM;
return -EPERM;
}
if (cqr->retries < 0) {
/* internal error 14 - start_IO run out of retries */
sprintf(errorstring, "14 %p", cqr);
dev_err(&device->cdev->dev, "An error occurred in the DASD "
"device driver, reason=%s\n", errorstring);
cqr->status = DASD_CQR_ERROR;
return -EIO;
}
cqr->startclk = get_clock();
cqr->starttime = jiffies;
cqr->retries--;
if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
cqr->lpm &= device->path_data.opm;
if (!cqr->lpm)
cqr->lpm = device->path_data.opm;
}
if (cqr->cpmode == 1) {
rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
(long) cqr, cqr->lpm);
} else {
rc = ccw_device_start(device->cdev, cqr->cpaddr,
(long) cqr, cqr->lpm, 0);
}
switch (rc) {
case 0:
cqr->status = DASD_CQR_IN_IO;
break;
case -EBUSY:
DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"start_IO: device busy, retry later");
break;
case -ETIMEDOUT:
DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"start_IO: request timeout, retry later");
break;
case -EACCES:
/* -EACCES indicates that the request used only a subset of the
* available paths and all these paths are gone. If the lpm of
* this request was only a subset of the opm (e.g. the ppm) then
* we just do a retry with all available paths.
* If we already use the full opm, something is amiss, and we
* need a full path verification.
*/
if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
DBF_DEV_EVENT(DBF_WARNING, device,
"start_IO: selected paths gone (%x)",
cqr->lpm);
} else if (cqr->lpm != device->path_data.opm) {
cqr->lpm = device->path_data.opm;
DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
"start_IO: selected paths gone,"
" retry on all paths");
} else {
DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"start_IO: all paths in opm gone,"
" do path verification");
dasd_generic_last_path_gone(device);
device->path_data.opm = 0;
device->path_data.ppm = 0;
device->path_data.npm = 0;
device->path_data.tbvpm =
ccw_device_get_path_mask(device->cdev);
}
break;
case -ENODEV:
DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"start_IO: -ENODEV device gone, retry");
break;
case -EIO:
DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"start_IO: -EIO device gone, retry");
break;
case -EINVAL:
/* most likely caused in power management context */
DBF_DEV_EVENT(DBF_WARNING, device, "%s",
"start_IO: -EINVAL device currently "
"not accessible");
break;
default:
/* internal error 11 - unknown rc */
snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
dev_err(&device->cdev->dev,
"An error occurred in the DASD device driver, "
"reason=%s\n", errorstring);
BUG();
break;
}
cqr->intrc = rc;
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_device_timeout(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 */
dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
dasd_schedule_device_bh(device);
}
/*
* Setup timeout for a device in jiffies.
*/
void dasd_device_set_timer(struct dasd_device *device, int expires)
{
if (expires == 0)
del_timer(&device->timer);
else
mod_timer(&device->timer, jiffies + expires);
}
/*
* Clear timeout for a device.
*/
void dasd_device_clear_timer(struct dasd_device *device)
{
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;
if (!intparm)
return;
cqr = (struct dasd_ccw_req *) intparm;
if (cqr->status != DASD_CQR_IN_IO) {
DBF_EVENT_DEVID(DBF_DEBUG, cdev,
"invalid status in handle_killed_request: "
"%02x", cqr->status);
return;
}
device = dasd_device_from_cdev_locked(cdev);
if (IS_ERR(device)) {
DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
"unable to get device from cdev");
return;
}
if (!cqr->startdev ||
device != cqr->startdev ||
strncmp(cqr->startdev->discipline->ebcname,
(char *) &cqr->magic, 4)) {
DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
"invalid device in request");
dasd_put_device(device);
return;
}
/* Schedule request to be retried. */
cqr->status = DASD_CQR_QUEUED;
dasd_device_clear_timer(device);
dasd_schedule_device_bh(device);
dasd_put_device(device);
}
void dasd_generic_handle_state_change(struct dasd_device *device)
{
/* First of all start sense subsystem status request. */
dasd_eer_snss(device);
dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
dasd_schedule_device_bh(device);
if (device->block)
dasd_schedule_block_bh(device->block);
}
/*
* 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;
kstat_cpu(smp_processor_id()).irqs[IOINT_DAS]++;
if (IS_ERR(irb)) {
switch (PTR_ERR(irb)) {
case -EIO:
break;
case -ETIMEDOUT:
DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
"request timed out\n", __func__);
break;
default:
DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
"unknown error %ld\n", __func__,
PTR_ERR(irb));
}
dasd_handle_killed_request(cdev, intparm);
return;
}
now = get_clock();
cqr = (struct dasd_ccw_req *) intparm;
/* check for conditions that should be handled immediately */
if (!cqr ||
!(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
scsw_cstat(&irb->scsw) == 0)) {
if (cqr)
memcpy(&cqr->irb, irb, sizeof(*irb));
device = dasd_device_from_cdev_locked(cdev);
if (IS_ERR(device))
return;
/* ignore unsolicited interrupts for DIAG discipline */
if (device->discipline == dasd_diag_discipline_pointer) {
dasd_put_device(device);
return;
}
device->discipline->dump_sense_dbf(device, irb, "int");
if (device->features & DASD_FEATURE_ERPLOG)
device->discipline->dump_sense(device, cqr, irb);
device->discipline->check_for_device_change(device, cqr, irb);
dasd_put_device(device);
}
if (!cqr)
return;
device = (struct dasd_device *) cqr->startdev;
if (!device ||
strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
"invalid device in request");
return;
}
/* Check for clear pending */
if (cqr->status == DASD_CQR_CLEAR_PENDING &&
scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
cqr->status = DASD_CQR_CLEARED;
dasd_device_clear_timer(device);
wake_up(&dasd_flush_wq);
dasd_schedule_device_bh(device);
return;
}
/* check status - the request might have been killed by dyn detach */
if (cqr->status != DASD_CQR_IN_IO) {
DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
"status %02x", dev_name(&cdev->dev), cqr->status);
return;
}
next = NULL;
expires = 0;
if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
scsw_cstat(&irb->scsw) == 0) {
/* request was completed successfully */
cqr->status = DASD_CQR_SUCCESS;
cqr->stopclk = now;
/* Start first request on queue if possible -> fast_io. */
if (cqr->devlist.next != &device->ccw_queue) {
next = list_entry(cqr->devlist.next,
struct dasd_ccw_req, devlist);
}
} else { /* error */
/*
* If we don't want complex ERP for this request, then just
* reset this and retry it in the fastpath
*/
if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
cqr->retries > 0) {
if (cqr->lpm == device->path_data.opm)
DBF_DEV_EVENT(DBF_DEBUG, device,
"default ERP in fastpath "
"(%i retries left)",
cqr->retries);
if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
cqr->lpm = device->path_data.opm;
cqr->status = DASD_CQR_QUEUED;
next = cqr;
} else
cqr->status = DASD_CQR_ERROR;
}
if (next && (next->status == DASD_CQR_QUEUED) &&
(!device->stopped)) {
if (device->discipline->start_IO(next) == 0)
expires = next->expires;
}
if (expires != 0)
dasd_device_set_timer(device, expires);
else
dasd_device_clear_timer(device);
dasd_schedule_device_bh(device);
}
enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
{
struct dasd_device *device;
device = dasd_device_from_cdev_locked(cdev);
if (IS_ERR(device))
goto out;
if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
device->state != device->target ||
!device->discipline->check_for_device_change){
dasd_put_device(device);
goto out;
}
if (device->discipline->dump_sense_dbf)
device->discipline->dump_sense_dbf(device, irb, "uc");
device->discipline->check_for_device_change(device, NULL, irb);
dasd_put_device(device);
out:
return UC_TODO_RETRY;
}
EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
/*
* If we have an error on a dasd_block layer request then we cancel
* and return all further requests from the same dasd_block as well.
*/
static void __dasd_device_recovery(struct dasd_device *device,
struct dasd_ccw_req *ref_cqr)
{
struct list_head *l, *n;
struct dasd_ccw_req *cqr;
/*
* only requeue request that came from the dasd_block layer
*/
if (!ref_cqr->block)
return;
list_for_each_safe(l, n, &device->ccw_queue) {
cqr = list_entry(l, struct dasd_ccw_req, devlist);
if (cqr->status == DASD_CQR_QUEUED &&
ref_cqr->block == cqr->block) {
cqr->status = DASD_CQR_CLEARED;
}
}
};
/*
* Remove those ccw requests from the queue that need to be returned
* to the upper layer.
*/
static void __dasd_device_process_ccw_queue(struct dasd_device *device,
struct list_head *final_queue)
{
struct list_head *l, *n;
struct dasd_ccw_req *cqr;
/* Process request with final status. */
list_for_each_safe(l, n, &device->ccw_queue) {
cqr = list_entry(l, struct dasd_ccw_req, devlist);
/* Stop list processing at the first non-final request. */
if (cqr->status == DASD_CQR_QUEUED ||
cqr->status == DASD_CQR_IN_IO ||
cqr->status == DASD_CQR_CLEAR_PENDING)
break;
if (cqr->status == DASD_CQR_ERROR) {
__dasd_device_recovery(device, cqr);
}
/* Rechain finished requests to final queue */
list_move_tail(&cqr->devlist, final_queue);
}
}
/*
* the cqrs from the final queue are returned to the upper layer
* by setting a dasd_block state and calling the callback function
*/
static void __dasd_device_process_final_queue(struct dasd_device *device,
struct list_head *final_queue)
{
struct list_head *l, *n;
struct dasd_ccw_req *cqr;
struct dasd_block *block;
void (*callback)(struct dasd_ccw_req *, void *data);
void *callback_data;
char errorstring[ERRORLENGTH];
list_for_each_safe(l, n, final_queue) {
cqr = list_entry(l, struct dasd_ccw_req, devlist);
list_del_init(&cqr->devlist);
block = cqr->block;
callback = cqr->callback;
callback_data = cqr->callback_data;
if (block)
spin_lock_bh(&block->queue_lock);
switch (cqr->status) {
case DASD_CQR_SUCCESS:
cqr->status = DASD_CQR_DONE;
break;
case DASD_CQR_ERROR:
cqr->status = DASD_CQR_NEED_ERP;
break;
case DASD_CQR_CLEARED:
cqr->status = DASD_CQR_TERMINATED;
break;
default:
/* internal error 12 - wrong cqr status*/
snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
dev_err(&device->cdev->dev,
"An error occurred in the DASD device driver, "
"reason=%s\n", errorstring);
BUG();
}
if (cqr->callback != NULL)
(callback)(cqr, callback_data);
if (block)
spin_unlock_bh(&block->queue_lock);
}
}
/*
* 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 void __dasd_device_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, devlist);
if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
(time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
if (device->discipline->term_IO(cqr) != 0) {
/* Hmpf, try again in 5 sec */
dev_err(&device->cdev->dev,
"cqr %p timed out (%lus) but cannot be "
"ended, retrying in 5 s\n",
cqr, (cqr->expires/HZ));
cqr->expires += 5*HZ;
dasd_device_set_timer(device, 5*HZ);
} else {
dev_err(&device->cdev->dev,
"cqr %p timed out (%lus), %i retries "
"remaining\n", cqr, (cqr->expires/HZ),
cqr->retries);
}
}
}
/*
* Take a look at the first request on the ccw queue and check
* if it needs to be started.
*/
static void __dasd_device_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, devlist);
if (cqr->status != DASD_CQR_QUEUED)
return;
/* when device is stopped, return request to previous layer
* exception: only the disconnect or unresumed bits are set and the
* cqr is a path verification request
*/
if (device->stopped &&
!(!(device->stopped & ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM))
&& test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))) {
cqr->intrc = -EAGAIN;
cqr->status = DASD_CQR_CLEARED;
dasd_schedule_device_bh(device);
return;
}
rc = device->discipline->start_IO(cqr);
if (rc == 0)
dasd_device_set_timer(device, cqr->expires);
else if (rc == -EACCES) {
dasd_schedule_device_bh(device);
} else
/* Hmpf, try again in 1/2 sec */
dasd_device_set_timer(device, 50);
}
static void __dasd_device_check_path_events(struct dasd_device *device)
{
int rc;
if (device->path_data.tbvpm) {
if (device->stopped & ~(DASD_STOPPED_DC_WAIT |
DASD_UNRESUMED_PM))
return;
rc = device->discipline->verify_path(
device, device->path_data.tbvpm);
if (rc)
dasd_device_set_timer(device, 50);
else
device->path_data.tbvpm = 0;
}
};
/*
* Go through all request on the dasd_device request queue,
* terminate them on the cdev if necessary, and return them to the
* submitting layer via callback.
* Note:
* Make sure that all 'submitting layers' still exist when
* this function is called!. In other words, when 'device' is a base
* device then all block layer requests must have been removed before
* via dasd_flush_block_queue.
*/
int dasd_flush_device_queue(struct dasd_device *device)
{
struct dasd_ccw_req *cqr, *n;
int rc;
struct list_head flush_queue;
INIT_LIST_HEAD(&flush_queue);
spin_lock_irq(get_ccwdev_lock(device->cdev));
rc = 0;
list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
/* Check status and move request to flush_queue */
switch (cqr->status) {
case DASD_CQR_IN_IO:
rc = device->discipline->term_IO(cqr);
if (rc) {
/* unable to terminate requeust */
dev_err(&device->cdev->dev,
"Flushing the DASD request queue "
"failed for request %p\n", cqr);
/* stop flush processing */
goto finished;
}
break;
case DASD_CQR_QUEUED:
cqr->stopclk = get_clock();
cqr->status = DASD_CQR_CLEARED;
break;
default: /* no need to modify the others */
break;
}
list_move_tail(&cqr->devlist, &flush_queue);
}
finished:
spin_unlock_irq(get_ccwdev_lock(device->cdev));
/*
* After this point all requests must be in state CLEAR_PENDING,
* CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
* one of the others.
*/
list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
wait_event(dasd_flush_wq,
(cqr->status != DASD_CQR_CLEAR_PENDING));
/*
* Now set each request back to TERMINATED, DONE or NEED_ERP
* and call the callback function of flushed requests
*/
__dasd_device_process_final_queue(device, &flush_queue);
return rc;
}
/*
* Acquire the device lock and process queues for the device.
*/
static void dasd_device_tasklet(struct dasd_device *device)
{
struct list_head final_queue;
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_device_check_expire(device);
/* find final requests on ccw queue */
__dasd_device_process_ccw_queue(device, &final_queue);
__dasd_device_check_path_events(device);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
/* Now call the callback function of requests with final status */
__dasd_device_process_final_queue(device, &final_queue);
spin_lock_irq(get_ccwdev_lock(device->cdev));
/* Now check if the head of the ccw queue needs to be started. */
__dasd_device_start_head(device);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
dasd_put_device(device);
}
/*
* Schedules a call to dasd_tasklet over the device tasklet.
*/
void dasd_schedule_device_bh(struct dasd_device *device)
{
/* Protect against rescheduling. */
if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
return;
dasd_get_device(device);
tasklet_hi_schedule(&device->tasklet);
}
void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
{
device->stopped |= bits;
}
EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
{
device->stopped &= ~bits;
if (!device->stopped)
wake_up(&generic_waitq);
}
EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
/*
* Queue a request to the head of the device ccw_queue.
* Start the I/O if possible.
*/
void dasd_add_request_head(struct dasd_ccw_req *cqr)
{
struct dasd_device *device;
unsigned long flags;
device = cqr->startdev;
spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
cqr->status = DASD_CQR_QUEUED;
list_add(&cqr->devlist, &device->ccw_queue);
/* let the bh start the request to keep them in order */
dasd_schedule_device_bh(device);
spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
}
/*
* Queue a request to the tail of the device ccw_queue.
* Start the I/O if possible.
*/
void dasd_add_request_tail(struct dasd_ccw_req *cqr)
{
struct dasd_device *device;
unsigned long flags;
device = cqr->startdev;
spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
cqr->status = DASD_CQR_QUEUED;
list_add_tail(&cqr->devlist, &device->ccw_queue);
/* let the bh start the request to keep them in order */
dasd_schedule_device_bh(device);
spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
}
/*
* Wakeup helper for the 'sleep_on' functions.
*/
static void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
{
spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
cqr->callback_data = DASD_SLEEPON_END_TAG;
spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
wake_up(&generic_waitq);
}
static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
{
struct dasd_device *device;
int rc;
device = cqr->startdev;
spin_lock_irq(get_ccwdev_lock(device->cdev));
rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
return rc;
}
/*
* checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
*/
static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
{
struct dasd_device *device;
dasd_erp_fn_t erp_fn;
if (cqr->status == DASD_CQR_FILLED)
return 0;
device = cqr->startdev;
if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
if (cqr->status == DASD_CQR_TERMINATED) {
device->discipline->handle_terminated_request(cqr);
return 1;
}
if (cqr->status == DASD_CQR_NEED_ERP) {
erp_fn = device->discipline->erp_action(cqr);
erp_fn(cqr);
return 1;
}
if (cqr->status == DASD_CQR_FAILED)
dasd_log_sense(cqr, &cqr->irb);
if (cqr->refers) {
__dasd_process_erp(device, cqr);
return 1;
}
}
return 0;
}
static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
{
if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
if (cqr->refers) /* erp is not done yet */
return 1;
return ((cqr->status != DASD_CQR_DONE) &&
(cqr->status != DASD_CQR_FAILED));
} else
return (cqr->status == DASD_CQR_FILLED);
}
static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
{
struct dasd_device *device;
int rc;
struct list_head ccw_queue;
struct dasd_ccw_req *cqr;
INIT_LIST_HEAD(&ccw_queue);
maincqr->status = DASD_CQR_FILLED;
device = maincqr->startdev;
list_add(&maincqr->blocklist, &ccw_queue);
for (cqr = maincqr; __dasd_sleep_on_loop_condition(cqr);
cqr = list_first_entry(&ccw_queue,
struct dasd_ccw_req, blocklist)) {
if (__dasd_sleep_on_erp(cqr))
continue;
if (cqr->status != DASD_CQR_FILLED) /* could be failed */
continue;
if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
!test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
cqr->status = DASD_CQR_FAILED;
cqr->intrc = -EPERM;
continue;
}
/* Non-temporary stop condition will trigger fail fast */
if (device->stopped & ~DASD_STOPPED_PENDING &&
test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
(!dasd_eer_enabled(device))) {
cqr->status = DASD_CQR_FAILED;
continue;
}
/* Don't try to start requests if device is stopped */
if (interruptible) {
rc = wait_event_interruptible(
generic_waitq, !(device->stopped));
if (rc == -ERESTARTSYS) {
cqr->status = DASD_CQR_FAILED;
maincqr->intrc = rc;
continue;
}
} else
wait_event(generic_waitq, !(device->stopped));
cqr->callback = dasd_wakeup_cb;
cqr->callback_data = DASD_SLEEPON_START_TAG;
dasd_add_request_tail(cqr);
if (interruptible) {
rc = wait_event_interruptible(
generic_waitq, _wait_for_wakeup(cqr));
if (rc == -ERESTARTSYS) {
dasd_cancel_req(cqr);
/* wait (non-interruptible) for final status */
wait_event(generic_waitq,
_wait_for_wakeup(cqr));
cqr->status = DASD_CQR_FAILED;
maincqr->intrc = rc;
continue;
}
} else
wait_event(generic_waitq, _wait_for_wakeup(cqr));
}
maincqr->endclk = get_clock();
if ((maincqr->status != DASD_CQR_DONE) &&
(maincqr->intrc != -ERESTARTSYS))
dasd_log_sense(maincqr, &maincqr->irb);
if (maincqr->status == DASD_CQR_DONE)
rc = 0;
else if (maincqr->intrc)
rc = maincqr->intrc;
else
rc = -EIO;
return rc;
}
/*
* Queue a request to the tail of the device ccw_queue and wait for
* it's completion.
*/
int dasd_sleep_on(struct dasd_ccw_req *cqr)
{
return _dasd_sleep_on(cqr, 0);
}
/*
* Queue a request to the tail of the device ccw_queue and wait
* interruptible for it's completion.
*/
int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
{
return _dasd_sleep_on(cqr, 1);
}
/*
* 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, devlist);
rc = device->discipline->term_IO(cqr);
if (!rc)
/*
* CQR terminated because a more important request is pending.
* Undo decreasing of retry counter because this is
* not an error case.
*/
cqr->retries++;
return rc;
}
int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
{
struct dasd_device *device;
int rc;
device = cqr->startdev;
if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
!test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
cqr->status = DASD_CQR_FAILED;
cqr->intrc = -EPERM;
return -EIO;
}
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;
}
cqr->callback = dasd_wakeup_cb;
cqr->callback_data = DASD_SLEEPON_START_TAG;
cqr->status = DASD_CQR_QUEUED;
list_add(&cqr->devlist, &device->ccw_queue);
/* let the bh start the request to keep them in order */
dasd_schedule_device_bh(device);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
wait_event(generic_waitq, _wait_for_wakeup(cqr));
if (cqr->status == DASD_CQR_DONE)
rc = 0;
else if (cqr->intrc)
rc = cqr->intrc;
else
rc = -EIO;
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.
* 0 if there was no need to terminate the request (not started yet)
* negative error code if termination failed
* Cancellation of a request is an asynchronous operation! The calling
* function has to wait until the request is properly returned via callback.
*/
int dasd_cancel_req(struct dasd_ccw_req *cqr)
{
struct dasd_device *device = cqr->startdev;
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 cleared */
cqr->status = DASD_CQR_CLEARED;
break;
case DASD_CQR_IN_IO:
/* request in IO - terminate IO and release again */
rc = device->discipline->term_IO(cqr);
if (rc) {
dev_err(&device->cdev->dev,
"Cancelling request %p failed with rc=%d\n",
cqr, rc);
} else {
cqr->stopclk = get_clock();
}
break;
default: /* already finished or clear pending - do nothing */
break;
}
spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
dasd_schedule_device_bh(device);
return rc;
}
/*
* SECTION: Operations of the dasd_block layer.
*/
/*
* Timeout function for dasd_block. This is used when the block layer
* is waiting for something that may not come reliably, (e.g. a state
* change interrupt)
*/
static void dasd_block_timeout(unsigned long ptr)
{
unsigned long flags;
struct dasd_block *block;
block = (struct dasd_block *) ptr;
spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
/* re-activate request queue */
dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
dasd_schedule_block_bh(block);
}
/*
* Setup timeout for a dasd_block in jiffies.
*/
void dasd_block_set_timer(struct dasd_block *block, int expires)
{
if (expires == 0)
del_timer(&block->timer);
else
mod_timer(&block->timer, jiffies + expires);
}
/*
* Clear timeout for a dasd_block.
*/
void dasd_block_clear_timer(struct dasd_block *block)
{
del_timer(&block->timer);
}
/*
* Process finished error recovery ccw.
*/
static 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_err(&device->cdev->dev, "ERP failed for the DASD\n");
erp_fn = device->discipline->erp_postaction(cqr);
erp_fn(cqr);
}
/*
* Fetch requests from the block device queue.
*/
static void __dasd_process_request_queue(struct dasd_block *block)
{
struct request_queue *queue;
struct request *req;
struct dasd_ccw_req *cqr;
struct dasd_device *basedev;
unsigned long flags;
queue = block->request_queue;
basedev = block->base;
/* 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 (basedev->state < DASD_STATE_READY) {
while ((req = blk_fetch_request(block->request_queue)))
__blk_end_request_all(req, -EIO);
return;
}
/* Now we try to fetch requests from the request queue */
while ((req = blk_peek_request(queue))) {
if (basedev->features & DASD_FEATURE_READONLY &&
rq_data_dir(req) == WRITE) {
DBF_DEV_EVENT(DBF_ERR, basedev,
"Rejecting write request %p",
req);
blk_start_request(req);
__blk_end_request_all(req, -EIO);
continue;
}
cqr = basedev->discipline->build_cp(basedev, block, req);
if (IS_ERR(cqr)) {
if (PTR_ERR(cqr) == -EBUSY)
break; /* normal end condition */
if (PTR_ERR(cqr) == -ENOMEM)
break; /* terminate request queue loop */
if (PTR_ERR(cqr) == -EAGAIN) {
/*
* The current request cannot be build right
* now, we have to try later. If this request
* is the head-of-queue we stop the device
* for 1/2 second.
*/
if (!list_empty(&block->ccw_queue))
break;
spin_lock_irqsave(
get_ccwdev_lock(basedev->cdev), flags);
dasd_device_set_stop_bits(basedev,
DASD_STOPPED_PENDING);
spin_unlock_irqrestore(
get_ccwdev_lock(basedev->cdev), flags);
dasd_block_set_timer(block, HZ/2);
break;
}
DBF_DEV_EVENT(DBF_ERR, basedev,
"CCW creation failed (rc=%ld) "
"on request %p",
PTR_ERR(cqr), req);
blk_start_request(req);
__blk_end_request_all(req, -EIO);
continue;
}
/*
* Note: callback is set to dasd_return_cqr_cb in
* __dasd_block_start_head to cover erp requests as well
*/
cqr->callback_data = (void *) req;
cqr->status = DASD_CQR_FILLED;
blk_start_request(req);
list_add_tail(&cqr->blocklist, &block->ccw_queue);
dasd_profile_start(block, cqr, req);
}
}
static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
{
struct request *req;
int status;
int error = 0;
req = (struct request *) cqr->callback_data;
dasd_profile_end(cqr->block, cqr, req);
status = cqr->block->base->discipline->free_cp(cqr, req);
if (status <= 0)
error = status ? status : -EIO;
__blk_end_request_all(req, error);
}
/*
* Process ccw request queue.
*/
static void __dasd_process_block_ccw_queue(struct dasd_block *block,
struct list_head *final_queue)
{
struct list_head *l, *n;
struct dasd_ccw_req *cqr;
dasd_erp_fn_t erp_fn;
unsigned long flags;
struct dasd_device *base = block->base;
restart:
/* Process request with final status. */
list_for_each_safe(l, n, &block->ccw_queue) {
cqr = list_entry(l, struct dasd_ccw_req, blocklist);
if (cqr->status != DASD_CQR_DONE &&
cqr->status != DASD_CQR_FAILED &&
cqr->status != DASD_CQR_NEED_ERP &&
cqr->status != DASD_CQR_TERMINATED)
continue;
if (cqr->status == DASD_CQR_TERMINATED) {
base->discipline->handle_terminated_request(cqr);
goto restart;
}
/* Process requests that may be recovered */
if (cqr->status == DASD_CQR_NEED_ERP) {
erp_fn = base->discipline->erp_action(cqr);
if (IS_ERR(erp_fn(cqr)))
continue;
goto restart;
}
/* log sense for fatal error */
if (cqr->status == DASD_CQR_FAILED) {
dasd_log_sense(cqr, &cqr->irb);
}
/* First of all call extended error reporting. */
if (dasd_eer_enabled(base) &&
cqr->status == DASD_CQR_FAILED) {
dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
/* restart request */
cqr->status = DASD_CQR_FILLED;
cqr->retries = 255;
spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
flags);
goto restart;
}
/* Process finished ERP request. */
if (cqr->refers) {
__dasd_process_erp(base, cqr);
goto restart;
}
/* Rechain finished requests to final queue */
cqr->endclk = get_clock();
list_move_tail(&cqr->blocklist, final_queue);
}
}
static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
{
dasd_schedule_block_bh(cqr->block);
}
static void __dasd_block_start_head(struct dasd_block *block)
{
struct dasd_ccw_req *cqr;
if (list_empty(&block->ccw_queue))
return;
/* We allways begin with the first requests on the queue, as some
* of previously started requests have to be enqueued on a
* dasd_device again for error recovery.
*/
list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
if (cqr->status != DASD_CQR_FILLED)
continue;
if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
!test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
cqr->status = DASD_CQR_FAILED;
cqr->intrc = -EPERM;
dasd_schedule_block_bh(block);
continue;
}
/* Non-temporary stop condition will trigger fail fast */
if (block->base->stopped & ~DASD_STOPPED_PENDING &&
test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
(!dasd_eer_enabled(block->base))) {
cqr->status = DASD_CQR_FAILED;
dasd_schedule_block_bh(block);
continue;
}
/* Don't try to start requests if device is stopped */
if (block->base->stopped)
return;
/* just a fail safe check, should not happen */
if (!cqr->startdev)
cqr->startdev = block->base;
/* make sure that the requests we submit find their way back */
cqr->callback = dasd_return_cqr_cb;
dasd_add_request_tail(cqr);
}
}
/*
* Central dasd_block layer routine. Takes requests from the generic
* block layer request queue, creates ccw requests, enqueues them on
* a dasd_device and processes ccw requests that have been returned.
*/
static void dasd_block_tasklet(struct dasd_block *block)
{
struct list_head final_queue;
struct list_head *l, *n;
struct dasd_ccw_req *cqr;
atomic_set(&block->tasklet_scheduled, 0);
INIT_LIST_HEAD(&final_queue);
spin_lock(&block->queue_lock);
/* Finish off requests on ccw queue */
__dasd_process_block_ccw_queue(block, &final_queue);
spin_unlock(&block->queue_lock);
/* Now call the callback function of requests with final status */
spin_lock_irq(&block->request_queue_lock);
list_for_each_safe(l, n, &final_queue) {
cqr = list_entry(l, struct dasd_ccw_req, blocklist);
list_del_init(&cqr->blocklist);
__dasd_cleanup_cqr(cqr);
}
spin_lock(&block->queue_lock);
/* Get new request from the block device request queue */
__dasd_process_request_queue(block);
/* Now check if the head of the ccw queue needs to be started. */
__dasd_block_start_head(block);
spin_unlock(&block->queue_lock);
spin_unlock_irq(&block->request_queue_lock);
dasd_put_device(block->base);
}
static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
{
wake_up(&dasd_flush_wq);
}
/*
* Go through all request on the dasd_block request queue, cancel them
* on the respective dasd_device, and return them to the generic
* block layer.
*/
static int dasd_flush_block_queue(struct dasd_block *block)
{
struct dasd_ccw_req *cqr, *n;
int rc, i;
struct list_head flush_queue;
INIT_LIST_HEAD(&flush_queue);
spin_lock_bh(&block->queue_lock);
rc = 0;
restart:
list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
/* if this request currently owned by a dasd_device cancel it */
if (cqr->status >= DASD_CQR_QUEUED)
rc = dasd_cancel_req(cqr);
if (rc < 0)
break;
/* Rechain request (including erp chain) so it won't be
* touched by the dasd_block_tasklet anymore.
* Replace the callback so we notice when the request
* is returned from the dasd_device layer.
*/
cqr->callback = _dasd_wake_block_flush_cb;
for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
list_move_tail(&cqr->blocklist, &flush_queue);
if (i > 1)
/* moved more than one request - need to restart */
goto restart;
}
spin_unlock_bh(&block->queue_lock);
/* Now call the callback function of flushed requests */
restart_cb:
list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
/* Process finished ERP request. */
if (cqr->refers) {
spin_lock_bh(&block->queue_lock);
__dasd_process_erp(block->base, cqr);
spin_unlock_bh(&block->queue_lock);
/* restart list_for_xx loop since dasd_process_erp
* might remove multiple elements */
goto restart_cb;
}
/* call the callback function */
spin_lock_irq(&block->request_queue_lock);
cqr->endclk = get_clock();
list_del_init(&cqr->blocklist);
__dasd_cleanup_cqr(cqr);
spin_unlock_irq(&block->request_queue_lock);
}
return rc;
}
/*
* Schedules a call to dasd_tasklet over the device tasklet.
*/
void dasd_schedule_block_bh(struct dasd_block *block)
{
/* Protect against rescheduling. */
if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
return;
/* life cycle of block is bound to it's base device */
dasd_get_device(block->base);
tasklet_hi_schedule(&block->tasklet);
}
/*
* SECTION: external block device operations
* (request queue handling, open, release, etc.)
*/
/*
* Dasd request queue function. Called from ll_rw_blk.c
*/
static void do_dasd_request(struct request_queue *queue)
{
struct dasd_block *block;
block = queue->queuedata;
spin_lock(&block->queue_lock);
/* Get new request from the block device request queue */
__dasd_process_request_queue(block);
/* Now check if the head of the ccw queue needs to be started. */
__dasd_block_start_head(block);
spin_unlock(&block->queue_lock);
}
/*
* Allocate and initialize request queue and default I/O scheduler.
*/
static int dasd_alloc_queue(struct dasd_block *block)
{
int rc;
block->request_queue = blk_init_queue(do_dasd_request,
&block->request_queue_lock);
if (block->request_queue == NULL)
return -ENOMEM;
block->request_queue->queuedata = block;
elevator_exit(block->request_queue->elevator);
block->request_queue->elevator = NULL;
rc = elevator_init(block->request_queue, "deadline");
if (rc) {
blk_cleanup_queue(block->request_queue);
return rc;
}
return 0;
}
/*
* Allocate and initialize request queue.
*/
static void dasd_setup_queue(struct dasd_block *block)
{
int max;
if (block->base->features & DASD_FEATURE_USERAW) {
/*
* the max_blocks value for raw_track access is 256
* it is higher than the native ECKD value because we
* only need one ccw per track
* so the max_hw_sectors are
* 2048 x 512B = 1024kB = 16 tracks
*/
max = 2048;
} else {
max = block->base->discipline->max_blocks << block->s2b_shift;
}
blk_queue_logical_block_size(block->request_queue,
block->bp_block);
blk_queue_max_hw_sectors(block->request_queue, max);
blk_queue_max_segments(block->request_queue, -1L);
/* with page sized segments we can translate each segement into
* one idaw/tidaw
*/
blk_queue_max_segment_size(block->request_queue, PAGE_SIZE);
blk_queue_segment_boundary(block->request_queue, PAGE_SIZE - 1);
}
/*
* Deactivate and free request queue.
*/
static void dasd_free_queue(struct dasd_block *block)
{
if (block->request_queue) {
blk_cleanup_queue(block->request_queue);
block->request_queue = NULL;
}
}
/*
* Flush request on the request queue.
*/
static void dasd_flush_request_queue(struct dasd_block *block)
{
struct request *req;
if (!block->request_queue)
return;
spin_lock_irq(&block->request_queue_lock);
while ((req = blk_fetch_request(block->request_queue)))
__blk_end_request_all(req, -EIO);
spin_unlock_irq(&block->request_queue_lock);
}
static int dasd_open(struct block_device *bdev, fmode_t mode)
{
struct dasd_device *base;
int rc;
base = dasd_device_from_gendisk(bdev->bd_disk);
if (!base)
return -ENODEV;
atomic_inc(&base->block->open_count);
if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
rc = -ENODEV;
goto unlock;
}
if (!try_module_get(base->discipline->owner)) {
rc = -EINVAL;
goto unlock;
}
if (dasd_probeonly) {
dev_info(&base->cdev->dev,
"Accessing the DASD failed because it is in "
"probeonly mode\n");
rc = -EPERM;
goto out;
}
if (base->state <= DASD_STATE_BASIC) {
DBF_DEV_EVENT(DBF_ERR, base, " %s",
" Cannot open unrecognized device");
rc = -ENODEV;
goto out;
}
if ((mode & FMODE_WRITE) &&
(test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
(base->features & DASD_FEATURE_READONLY))) {
rc = -EROFS;
goto out;
}
dasd_put_device(base);
return 0;
out:
module_put(base->discipline->owner);
unlock:
atomic_dec(&base->block->open_count);
dasd_put_device(base);
return rc;
}
static int dasd_release(struct gendisk *disk, fmode_t mode)
{
struct dasd_device *base;
base = dasd_device_from_gendisk(disk);
if (!base)
return -ENODEV;
atomic_dec(&base->block->open_count);
module_put(base->discipline->owner);
dasd_put_device(base);
return 0;
}
/*
* Return disk geometry.
*/
static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
struct dasd_device *base;
base = dasd_device_from_gendisk(bdev->bd_disk);
if (!base)
return -ENODEV;
if (!base->discipline ||
!base->discipline->fill_geometry) {
dasd_put_device(base);
return -EINVAL;
}
base->discipline->fill_geometry(base->block, geo);
geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
dasd_put_device(base);
return 0;
}
const struct block_device_operations
dasd_device_operations = {
.owner = THIS_MODULE,
.open = dasd_open,
.release = dasd_release,
.ioctl = dasd_ioctl,
.compat_ioctl = dasd_ioctl,
.getgeo = dasd_getgeo,
};
/*******************************************************************************
* end of block device operations
*/
static void
dasd_exit(void)
{
#ifdef CONFIG_PROC_FS
dasd_proc_exit();
#endif
dasd_eer_exit();
if (dasd_page_cache != NULL) {
kmem_cache_destroy(dasd_page_cache);
dasd_page_cache = NULL;
}
dasd_gendisk_exit();
dasd_devmap_exit();
if (dasd_debug_area != NULL) {
debug_unregister(dasd_debug_area);
dasd_debug_area = NULL;
}
}
/*
* SECTION: common functions for ccw_driver use
*/
/*
* Is the device read-only?
* Note that this function does not report the setting of the
* readonly device attribute, but how it is configured in z/VM.
*/
int dasd_device_is_ro(struct dasd_device *device)
{
struct ccw_dev_id dev_id;
struct diag210 diag_data;
int rc;
if (!MACHINE_IS_VM)
return 0;
ccw_device_get_id(device->cdev, &dev_id);
memset(&diag_data, 0, sizeof(diag_data));
diag_data.vrdcdvno = dev_id.devno;
diag_data.vrdclen = sizeof(diag_data);
rc = diag210(&diag_data);
if (rc == 0 || rc == 2) {
return diag_data.vrdcvfla & 0x80;
} else {
DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
dev_id.devno, rc);
return 0;
}
}
EXPORT_SYMBOL_GPL(dasd_device_is_ro);
static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
{
struct ccw_device *cdev = data;
int ret;
ret = ccw_device_set_online(cdev);
if (ret)
pr_warning("%s: Setting the DASD online failed with rc=%d\n",
dev_name(&cdev->dev), ret);
}
/*
* 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) {
DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
"dasd_generic_probe: could not add "
"sysfs entries");
return ret;
}
cdev->handler = &dasd_int_handler;
/*
* Automatically online either all dasd devices (dasd_autodetect)
* or all devices specified with dasd= parameters during
* initial probe.
*/
if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
(dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
async_schedule(dasd_generic_auto_online, cdev);
return 0;
}
/*
* 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;
struct dasd_block *block;
cdev->handler = NULL;
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. */
block = device->block;
dasd_delete_device(device);
/*
* life cycle of block is bound to device, so delete it after
* device was safely removed
*/
if (block)
dasd_free_block(block);
}
/*
* 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 *base_discipline)
{
struct dasd_discipline *discipline;
struct dasd_device *device;
int rc;
/* first online clears initial online feature flag */
dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
device = dasd_create_device(cdev);
if (IS_ERR(device))
return PTR_ERR(device);
discipline = base_discipline;
if (device->features & DASD_FEATURE_USEDIAG) {
if (!dasd_diag_discipline_pointer) {
pr_warning("%s Setting the DASD online failed because "
"of missing DIAG discipline\n",
dev_name(&cdev->dev));
dasd_delete_device(device);
return -ENODEV;
}
discipline = dasd_diag_discipline_pointer;
}
if (!try_module_get(base_discipline->owner)) {
dasd_delete_device(device);
return -EINVAL;
}
if (!try_module_get(discipline->owner)) {
module_put(base_discipline->owner);
dasd_delete_device(device);
return -EINVAL;
}
device->base_discipline = base_discipline;
device->discipline = discipline;
/* check_device will allocate block device if necessary */
rc = discipline->check_device(device);
if (rc) {
pr_warning("%s Setting the DASD online with discipline %s "
"failed with rc=%i\n",
dev_name(&cdev->dev), discipline->name, rc);
module_put(discipline->owner);
module_put(base_discipline->owner);
dasd_delete_device(device);
return rc;
}
dasd_set_target_state(device, DASD_STATE_ONLINE);
if (device->state <= DASD_STATE_KNOWN) {
pr_warning("%s Setting the DASD online failed because of a "
"missing discipline\n", dev_name(&cdev->dev));
rc = -ENODEV;
dasd_set_target_state(device, DASD_STATE_NEW);
if (device->block)
dasd_free_block(device->block);
dasd_delete_device(device);
} else
pr_debug("dasd_generic device %s found\n",
dev_name(&cdev->dev));
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;
struct dasd_block *block;
int max_count, open_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.
*/
if (device->block) {
max_count = device->block->bdev ? 0 : -1;
open_count = atomic_read(&device->block->open_count);
if (open_count > max_count) {
if (open_count > 0)
pr_warning("%s: The DASD cannot be set offline "
"with open count %i\n",
dev_name(&cdev->dev), open_count);
else
pr_warning("%s: The DASD cannot be set offline "
"while it is in use\n",
dev_name(&cdev->dev));
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. */
block = device->block;
dasd_delete_device(device);
/*
* life cycle of block is bound to device, so delete it after
* device was safely removed
*/
if (block)
dasd_free_block(block);
return 0;
}
int dasd_generic_last_path_gone(struct dasd_device *device)
{
struct dasd_ccw_req *cqr;
dev_warn(&device->cdev->dev, "No operational channel path is left "
"for the device\n");
DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
/* First of all call extended error reporting. */
dasd_eer_write(device, NULL, DASD_EER_NOPATH);
if (device->state < DASD_STATE_BASIC)
return 0;
/* Device is active. We want to keep it. */
list_for_each_entry(cqr, &device->ccw_queue, devlist)
if ((cqr->status == DASD_CQR_IN_IO) ||
(cqr->status == DASD_CQR_CLEAR_PENDING)) {
cqr->status = DASD_CQR_QUEUED;
cqr->retries++;
}
dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
dasd_device_clear_timer(device);
dasd_schedule_device_bh(device);
return 1;
}
EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
int dasd_generic_path_operational(struct dasd_device *device)
{
dev_info(&device->cdev->dev, "A channel path to the device has become "
"operational\n");
DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
if (device->stopped & DASD_UNRESUMED_PM) {
dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
dasd_restore_device(device);
return 1;
}
dasd_schedule_device_bh(device);
if (device->block)
dasd_schedule_block_bh(device->block);
return 1;
}
EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
int dasd_generic_notify(struct ccw_device *cdev, int event)
{
struct dasd_device *device;
int ret;
device = dasd_device_from_cdev_locked(cdev);
if (IS_ERR(device))
return 0;
ret = 0;
switch (event) {
case CIO_GONE:
case CIO_BOXED:
case CIO_NO_PATH:
device->path_data.opm = 0;
device->path_data.ppm = 0;
device->path_data.npm = 0;
ret = dasd_generic_last_path_gone(device);
break;
case CIO_OPER:
ret = 1;
if (device->path_data.opm)
ret = dasd_generic_path_operational(device);
break;
}
dasd_put_device(device);
return ret;
}
void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
{
int chp;
__u8 oldopm, eventlpm;
struct dasd_device *device;
device = dasd_device_from_cdev_locked(cdev);
if (IS_ERR(device))
return;
for (chp = 0; chp < 8; chp++) {
eventlpm = 0x80 >> chp;
if (path_event[chp] & PE_PATH_GONE) {
oldopm = device->path_data.opm;
device->path_data.opm &= ~eventlpm;
device->path_data.ppm &= ~eventlpm;
device->path_data.npm &= ~eventlpm;
if (oldopm && !device->path_data.opm)
dasd_generic_last_path_gone(device);
}
if (path_event[chp] & PE_PATH_AVAILABLE) {
device->path_data.opm &= ~eventlpm;
device->path_data.ppm &= ~eventlpm;
device->path_data.npm &= ~eventlpm;
device->path_data.tbvpm |= eventlpm;
dasd_schedule_device_bh(device);
}
}
dasd_put_device(device);
}
EXPORT_SYMBOL_GPL(dasd_generic_path_event);
int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
{
if (!device->path_data.opm && lpm) {
device->path_data.opm = lpm;
dasd_generic_path_operational(device);
} else
device->path_data.opm |= lpm;
return 0;
}
EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
int dasd_generic_pm_freeze(struct ccw_device *cdev)
{
struct dasd_ccw_req *cqr, *n;
int rc;
struct list_head freeze_queue;
struct dasd_device *device = dasd_device_from_cdev(cdev);
if (IS_ERR(device))
return PTR_ERR(device);
if (device->discipline->freeze)
rc = device->discipline->freeze(device);
/* disallow new I/O */
dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
/* clear active requests */
INIT_LIST_HEAD(&freeze_queue);
spin_lock_irq(get_ccwdev_lock(cdev));
rc = 0;
list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
/* Check status and move request to flush_queue */
if (cqr->status == DASD_CQR_IN_IO) {
rc = device->discipline->term_IO(cqr);
if (rc) {
/* unable to terminate requeust */
dev_err(&device->cdev->dev,
"Unable to terminate request %p "
"on suspend\n", cqr);
spin_unlock_irq(get_ccwdev_lock(cdev));
dasd_put_device(device);
return rc;
}
}
list_move_tail(&cqr->devlist, &freeze_queue);
}
spin_unlock_irq(get_ccwdev_lock(cdev));
list_for_each_entry_safe(cqr, n, &freeze_queue, devlist) {
wait_event(dasd_flush_wq,
(cqr->status != DASD_CQR_CLEAR_PENDING));
if (cqr->status == DASD_CQR_CLEARED)
cqr->status = DASD_CQR_QUEUED;
}
/* move freeze_queue to start of the ccw_queue */
spin_lock_irq(get_ccwdev_lock(cdev));
list_splice_tail(&freeze_queue, &device->ccw_queue);
spin_unlock_irq(get_ccwdev_lock(cdev));
dasd_put_device(device);
return rc;
}
EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
int dasd_generic_restore_device(struct ccw_device *cdev)
{
struct dasd_device *device = dasd_device_from_cdev(cdev);
int rc = 0;
if (IS_ERR(device))
return PTR_ERR(device);
/* allow new IO again */
dasd_device_remove_stop_bits(device,
(DASD_STOPPED_PM | DASD_UNRESUMED_PM));
dasd_schedule_device_bh(device);
/*
* call discipline restore function
* if device is stopped do nothing e.g. for disconnected devices
*/
if (device->discipline->restore && !(device->stopped))
rc = device->discipline->restore(device);
if (rc || device->stopped)
/*
* if the resume failed for the DASD we put it in
* an UNRESUMED stop state
*/
device->stopped |= DASD_UNRESUMED_PM;
if (device->block)
dasd_schedule_block_bh(device->block);
dasd_put_device(device);
return 0;
}
EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
void *rdc_buffer,
int rdc_buffer_size,
int magic)
{
struct dasd_ccw_req *cqr;
struct ccw1 *ccw;
unsigned long *idaw;
cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device);
if (IS_ERR(cqr)) {
/* internal error 13 - Allocating the RDC request failed*/
dev_err(&device->cdev->dev,
"An error occurred in the DASD device driver, "
"reason=%s\n", "13");
return cqr;
}
ccw = cqr->cpaddr;
ccw->cmd_code = CCW_CMD_RDC;
if (idal_is_needed(rdc_buffer, rdc_buffer_size)) {
idaw = (unsigned long *) (cqr->data);
ccw->cda = (__u32)(addr_t) idaw;
ccw->flags = CCW_FLAG_IDA;
idaw = idal_create_words(idaw, rdc_buffer, rdc_buffer_size);
} else {
ccw->cda = (__u32)(addr_t) rdc_buffer;
ccw->flags = 0;
}
ccw->count = rdc_buffer_size;
cqr->startdev = device;
cqr->memdev = device;
cqr->expires = 10*HZ;
cqr->retries = 256;
cqr->buildclk = get_clock();
cqr->status = DASD_CQR_FILLED;
return cqr;
}
int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
void *rdc_buffer, int rdc_buffer_size)
{
int ret;
struct dasd_ccw_req *cqr;
cqr = dasd_generic_build_rdc(device, rdc_buffer, rdc_buffer_size,
magic);
if (IS_ERR(cqr))
return PTR_ERR(cqr);
ret = dasd_sleep_on(cqr);
dasd_sfree_request(cqr, cqr->memdev);
return ret;
}
EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
/*
* In command mode and transport mode we need to look for sense
* data in different places. The sense data itself is allways
* an array of 32 bytes, so we can unify the sense data access
* for both modes.
*/
char *dasd_get_sense(struct irb *irb)
{
struct tsb *tsb = NULL;
char *sense = NULL;
if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
if (irb->scsw.tm.tcw)
tsb = tcw_get_tsb((struct tcw *)(unsigned long)
irb->scsw.tm.tcw);
if (tsb && tsb->length == 64 && tsb->flags)
switch (tsb->flags & 0x07) {
case 1: /* tsa_iostat */
sense = tsb->tsa.iostat.sense;
break;
case 2: /* tsa_ddpc */
sense = tsb->tsa.ddpc.sense;
break;
default:
/* currently we don't use interrogate data */
break;
}
} else if (irb->esw.esw0.erw.cons) {
sense = irb->ecw;
}
return sense;
}
EXPORT_SYMBOL_GPL(dasd_get_sense);
static int __init dasd_init(void)
{
int rc;
init_waitqueue_head(&dasd_init_waitq);
init_waitqueue_head(&dasd_flush_wq);
init_waitqueue_head(&generic_waitq);
/* register 'common' DASD debug area, used for all DBF_XXX calls */
dasd_debug_area = debug_register("dasd", 1, 1, 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_WARNING);
DBF_EVENT(DBF_EMERG, "%s", "debug area created");
dasd_diag_discipline_pointer = NULL;
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_eer_init();
if (rc)
goto failed;
#ifdef CONFIG_PROC_FS
rc = dasd_proc_init();
if (rc)
goto failed;
#endif
return 0;
failed:
pr_info("The DASD device driver could not be initialized\n");
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_device_clear_timer);
EXPORT_SYMBOL(dasd_block_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_device_bh);
EXPORT_SYMBOL(dasd_schedule_block_bh);
EXPORT_SYMBOL(dasd_set_target_state);
EXPORT_SYMBOL(dasd_device_set_timer);
EXPORT_SYMBOL(dasd_block_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_handle_state_change);
EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
EXPORT_SYMBOL_GPL(dasd_alloc_block);
EXPORT_SYMBOL_GPL(dasd_free_block);
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