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linux/drivers/s390/block/dasd.c
Arnd Bergmann cfdb00a77e s390/block: kill the big kernel lock 
The dasd and dcssblk drivers gained the big
kernel lock in the recent pushdown from the
block layer, but they don't really need it,
so remove the calls without a replacement.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-s390@vger.kernel.org
2010-09-26 16:25:51 +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/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);
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) {
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;
/* Sanity checks */
BUG_ON(datasize > PAGE_SIZE ||
(cplength*sizeof(struct ccw1)) > PAGE_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->retries--;
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->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 (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_DEBUG, device, "%s",
"start_IO: device busy, retry later");
break;
case -ETIMEDOUT:
DBF_DEV_EVENT(DBF_DEBUG, 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_DEBUG, device, "%s",
"start_IO: selected pathes gone,"
" retry on all pathes");
break;
case -ENODEV:
DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
"start_IO: -ENODEV device gone, retry");
break;
case -EIO:
DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
"start_IO: -EIO device gone, retry");
break;
case -EINVAL:
/* most likely caused in power management context */
DBF_DEV_EVENT(DBF_DEBUG, 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;
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();
/* check for unsolicited interrupts */
cqr = (struct dasd_ccw_req *) intparm;
if (!cqr || ((scsw_cc(&irb->scsw) == 1) &&
(scsw_fctl(&irb->scsw) & SCSW_FCTL_START_FUNC) &&
(scsw_stctl(&irb->scsw) & SCSW_STCTL_STATUS_PEND))) {
if (cqr && cqr->status == DASD_CQR_IN_IO)
cqr->status = DASD_CQR_QUEUED;
device = dasd_device_from_cdev_locked(cdev);
if (!IS_ERR(device)) {
dasd_device_clear_timer(device);
device->discipline->handle_unsolicited_interrupt(device,
irb);
dasd_put_device(device);
}
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 */
memcpy(&cqr->irb, irb, sizeof(struct irb));
/* log sense for every failed I/O to s390 debugfeature */
dasd_log_sense_dbf(cqr, irb);
if (device->features & DASD_FEATURE_ERPLOG) {
dasd_log_sense(cqr, irb);
}
/*
* 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 == LPM_ANYPATH)
DBF_DEV_EVENT(DBF_DEBUG, device,
"default ERP in fastpath "
"(%i retries left)",
cqr->retries);
cqr->lpm = LPM_ANYPATH;
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->handle_unsolicited_interrupt){
dasd_put_device(device);
goto out;
}
dasd_device_clear_timer(device);
device->discipline->handle_unsolicited_interrupt(device, 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 */
if (device->stopped) {
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);
}
/*
* 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);
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;
/* 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;
if (list_empty(&device->ccw_queue))
return 0;
cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
return device->discipline->term_IO(cqr);
}
int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
{
struct dasd_device *device;
int rc;
device = cqr->startdev;
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 (!blk_queue_plugged(queue) && (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;
/* 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;
blk_queue_logical_block_size(block->request_queue, block->bp_block);
max = block->base->discipline->max_blocks << block->s2b_shift;
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);
blk_queue_ordered(block->request_queue, QUEUE_ORDERED_DRAIN);
}
/*
* 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_block *block = bdev->bd_disk->private_data;
struct dasd_device *base;
int rc;
if (!block)
return -ENODEV;
base = block->base;
atomic_inc(&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;
}
return 0;
out:
module_put(base->discipline->owner);
unlock:
atomic_dec(&block->open_count);
return rc;
}
static int dasd_release(struct gendisk *disk, fmode_t mode)
{
struct dasd_block *block = disk->private_data;
atomic_dec(&block->open_count);
module_put(block->base->discipline->owner);
return 0;
}
/*
* Return disk geometry.
*/
static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
struct dasd_block *block;
struct dasd_device *base;
block = bdev->bd_disk->private_data;
if (!block)
return -ENODEV;
base = block->base;
if (!base->discipline ||
!base->discipline->fill_geometry)
return -EINVAL;
base->discipline->fill_geometry(block, geo);
geo->start = get_start_sect(bdev) >> block->s2b_shift;
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;
device->block = NULL;
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;
device->block = NULL;
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_notify(struct ccw_device *cdev, int event)
{
struct dasd_device *device;
struct dasd_ccw_req *cqr;
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:
/* First of all call extended error reporting. */
dasd_eer_write(device, NULL, DASD_EER_NOPATH);
if (device->state < DASD_STATE_BASIC)
break;
/* 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_QUEUED;
cqr->retries++;
}
dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
dasd_device_clear_timer(device);
dasd_schedule_device_bh(device);
ret = 1;
break;
case CIO_OPER:
/* FIXME: add a sanity check. */
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);
ret = 1;
break;
}
dasd_schedule_device_bh(device);
if (device->block)
dasd_schedule_block_bh(device->block);
ret = 1;
break;
}
dasd_put_device(device);
return ret;
}
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);
/* 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));
if (device->discipline->freeze)
rc = device->discipline->freeze(device);
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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