diff options
Diffstat (limited to 'drivers/s390/block/dasd.c')
| -rw-r--r-- | drivers/s390/block/dasd.c | 2065 |
1 files changed, 2065 insertions, 0 deletions
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c new file mode 100644 index 000000000000..b755bac6ccbc --- /dev/null +++ b/drivers/s390/block/dasd.c @@ -0,0 +1,2065 @@ +/* + * File...........: linux/drivers/s390/block/dasd.c + * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com> + * Horst Hummel <Horst.Hummel@de.ibm.com> + * Carsten Otte <Cotte@de.ibm.com> + * Martin Schwidefsky <schwidefsky@de.ibm.com> + * Bugreports.to..: <Linux390@de.ibm.com> + * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001 + * + * $Revision: 1.158 $ + */ + +#include <linux/config.h> +#include <linux/kmod.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/ctype.h> +#include <linux/major.h> +#include <linux/slab.h> +#include <linux/buffer_head.h> + +#include <asm/ccwdev.h> +#include <asm/ebcdic.h> +#include <asm/idals.h> +#include <asm/todclk.h> + +/* This is ugly... */ +#define PRINTK_HEADER "dasd:" + +#include "dasd_int.h" +/* + * SECTION: Constant definitions to be used within this file + */ +#define DASD_CHANQ_MAX_SIZE 4 + +/* + * SECTION: exported variables of dasd.c + */ +debug_info_t *dasd_debug_area; +struct dasd_discipline *dasd_diag_discipline_pointer; + +MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>"); +MODULE_DESCRIPTION("Linux on S/390 DASD device driver," + " Copyright 2000 IBM Corporation"); +MODULE_SUPPORTED_DEVICE("dasd"); +MODULE_PARM(dasd, "1-" __MODULE_STRING(256) "s"); +MODULE_LICENSE("GPL"); + +/* + * SECTION: prototypes for static functions of dasd.c + */ +static int dasd_alloc_queue(struct dasd_device * device); +static void dasd_setup_queue(struct dasd_device * device); +static void dasd_free_queue(struct dasd_device * device); +static void dasd_flush_request_queue(struct dasd_device *); +static void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *); +static void dasd_flush_ccw_queue(struct dasd_device *, int); +static void dasd_tasklet(struct dasd_device *); +static void do_kick_device(void *data); + +/* + * SECTION: Operations on the device structure. + */ +static wait_queue_head_t dasd_init_waitq; + +/* + * Allocate memory for a new device structure. + */ +struct dasd_device * +dasd_alloc_device(void) +{ + struct dasd_device *device; + + device = kmalloc(sizeof (struct dasd_device), GFP_ATOMIC); + if (device == NULL) + return ERR_PTR(-ENOMEM); + memset(device, 0, sizeof (struct dasd_device)); + /* open_count = 0 means device online but not in use */ + atomic_set(&device->open_count, -1); + + /* Get two pages for normal block device operations. */ + device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1); + if (device->ccw_mem == NULL) { + kfree(device); + return ERR_PTR(-ENOMEM); + } + /* Get one page for error recovery. */ + device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA); + if (device->erp_mem == NULL) { + free_pages((unsigned long) device->ccw_mem, 1); + kfree(device); + return ERR_PTR(-ENOMEM); + } + + dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2); + dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE); + spin_lock_init(&device->mem_lock); + spin_lock_init(&device->request_queue_lock); + atomic_set (&device->tasklet_scheduled, 0); + tasklet_init(&device->tasklet, + (void (*)(unsigned long)) dasd_tasklet, + (unsigned long) device); + INIT_LIST_HEAD(&device->ccw_queue); + init_timer(&device->timer); + INIT_WORK(&device->kick_work, do_kick_device, device); + device->state = DASD_STATE_NEW; + device->target = DASD_STATE_NEW; + + return device; +} + +/* + * Free memory of a device structure. + */ +void +dasd_free_device(struct dasd_device *device) +{ + if (device->private) + kfree(device->private); + free_page((unsigned long) device->erp_mem); + free_pages((unsigned long) device->ccw_mem, 1); + kfree(device); +} + +/* + * Make a new device known to the system. + */ +static inline int +dasd_state_new_to_known(struct dasd_device *device) +{ + int rc; + + /* + * As long as the device is not in state DASD_STATE_NEW we want to + * keep the reference count > 0. + */ + dasd_get_device(device); + + rc = dasd_alloc_queue(device); + if (rc) { + dasd_put_device(device); + return rc; + } + + device->state = DASD_STATE_KNOWN; + return 0; +} + +/* + * Let the system forget about a device. + */ +static inline void +dasd_state_known_to_new(struct dasd_device * device) +{ + /* Forget the discipline information. */ + device->discipline = NULL; + device->state = DASD_STATE_NEW; + + dasd_free_queue(device); + + /* Give up reference we took in dasd_state_new_to_known. */ + dasd_put_device(device); +} + +/* + * Request the irq line for the device. + */ +static inline int +dasd_state_known_to_basic(struct dasd_device * device) +{ + int rc; + + /* Allocate and register gendisk structure. */ + rc = dasd_gendisk_alloc(device); + if (rc) + return rc; + + /* register 'device' debug area, used for all DBF_DEV_XXX calls */ + device->debug_area = debug_register(device->cdev->dev.bus_id, 0, 2, + 8 * sizeof (long)); + debug_register_view(device->debug_area, &debug_sprintf_view); + debug_set_level(device->debug_area, DBF_EMERG); + DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created"); + + device->state = DASD_STATE_BASIC; + return 0; +} + +/* + * Release the irq line for the device. Terminate any running i/o. + */ +static inline void +dasd_state_basic_to_known(struct dasd_device * device) +{ + dasd_gendisk_free(device); + dasd_flush_ccw_queue(device, 1); + DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device); + if (device->debug_area != NULL) { + debug_unregister(device->debug_area); + device->debug_area = NULL; + } + device->state = DASD_STATE_KNOWN; +} + +/* + * Do the initial analysis. The do_analysis function may return + * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC + * until the discipline decides to continue the startup sequence + * by calling the function dasd_change_state. The eckd disciplines + * uses this to start a ccw that detects the format. The completion + * interrupt for this detection ccw uses the kernel event daemon to + * trigger the call to dasd_change_state. All this is done in the + * discipline code, see dasd_eckd.c. + * After the analysis ccw is done (do_analysis returned 0 or error) + * the block device is setup. Either a fake disk is added to allow + * formatting or a proper device request queue is created. + */ +static inline int +dasd_state_basic_to_ready(struct dasd_device * device) +{ + int rc; + + rc = 0; + if (device->discipline->do_analysis != NULL) + rc = device->discipline->do_analysis(device); + if (rc) + return rc; + dasd_setup_queue(device); + device->state = DASD_STATE_READY; + if (dasd_scan_partitions(device) != 0) + device->state = DASD_STATE_BASIC; + return 0; +} + +/* + * Remove device from block device layer. Destroy dirty buffers. + * Forget format information. Check if the target level is basic + * and if it is create fake disk for formatting. + */ +static inline void +dasd_state_ready_to_basic(struct dasd_device * device) +{ + dasd_flush_ccw_queue(device, 0); + dasd_destroy_partitions(device); + dasd_flush_request_queue(device); + device->blocks = 0; + device->bp_block = 0; + device->s2b_shift = 0; + device->state = DASD_STATE_BASIC; +} + +/* + * Make the device online and schedule the bottom half to start + * the requeueing of requests from the linux request queue to the + * ccw queue. + */ +static inline int +dasd_state_ready_to_online(struct dasd_device * device) +{ + device->state = DASD_STATE_ONLINE; + dasd_schedule_bh(device); + return 0; +} + +/* + * Stop the requeueing of requests again. + */ +static inline void +dasd_state_online_to_ready(struct dasd_device * device) +{ + device->state = DASD_STATE_READY; +} + +/* + * Device startup state changes. + */ +static inline int +dasd_increase_state(struct dasd_device *device) +{ + int rc; + + rc = 0; + if (device->state == DASD_STATE_NEW && + device->target >= DASD_STATE_KNOWN) + rc = dasd_state_new_to_known(device); + + if (!rc && + device->state == DASD_STATE_KNOWN && + device->target >= DASD_STATE_BASIC) + rc = dasd_state_known_to_basic(device); + + if (!rc && + device->state == DASD_STATE_BASIC && + device->target >= DASD_STATE_READY) + rc = dasd_state_basic_to_ready(device); + + if (!rc && + device->state == DASD_STATE_READY && + device->target >= DASD_STATE_ONLINE) + rc = dasd_state_ready_to_online(device); + + return rc; +} + +/* + * Device shutdown state changes. + */ +static inline int +dasd_decrease_state(struct dasd_device *device) +{ + if (device->state == DASD_STATE_ONLINE && + device->target <= DASD_STATE_READY) + dasd_state_online_to_ready(device); + + if (device->state == DASD_STATE_READY && + device->target <= DASD_STATE_BASIC) + dasd_state_ready_to_basic(device); + + if (device->state == DASD_STATE_BASIC && + device->target <= DASD_STATE_KNOWN) + dasd_state_basic_to_known(device); + + if (device->state == DASD_STATE_KNOWN && + device->target <= DASD_STATE_NEW) + dasd_state_known_to_new(device); + + return 0; +} + +/* + * This is the main startup/shutdown routine. + */ +static void +dasd_change_state(struct dasd_device *device) +{ + int rc; + + if (device->state == device->target) + /* Already where we want to go today... */ + return; + if (device->state < device->target) + rc = dasd_increase_state(device); + else + rc = dasd_decrease_state(device); + if (rc && rc != -EAGAIN) + device->target = device->state; + + if (device->state == device->target) + wake_up(&dasd_init_waitq); +} + +/* + * Kick starter for devices that did not complete the startup/shutdown + * procedure or were sleeping because of a pending state. + * dasd_kick_device will schedule a call do do_kick_device to the kernel + * event daemon. + */ +static void +do_kick_device(void *data) +{ + struct dasd_device *device; + + device = (struct dasd_device *) data; + dasd_change_state(device); + dasd_schedule_bh(device); + dasd_put_device(device); +} + +void +dasd_kick_device(struct dasd_device *device) +{ + dasd_get_device(device); + /* queue call to dasd_kick_device to the kernel event daemon. */ + schedule_work(&device->kick_work); +} + +/* + * Set the target state for a device and starts the state change. + */ +void +dasd_set_target_state(struct dasd_device *device, int target) +{ + /* If we are in probeonly mode stop at DASD_STATE_READY. */ + if (dasd_probeonly && target > DASD_STATE_READY) + target = DASD_STATE_READY; + if (device->target != target) { + if (device->state == target) + wake_up(&dasd_init_waitq); + device->target = target; + } + if (device->state != device->target) + dasd_change_state(device); +} + +/* + * Enable devices with device numbers in [from..to]. + */ +static inline int +_wait_for_device(struct dasd_device *device) +{ + return (device->state == device->target); +} + +void +dasd_enable_device(struct dasd_device *device) +{ + dasd_set_target_state(device, DASD_STATE_ONLINE); + if (device->state <= DASD_STATE_KNOWN) + /* No discipline for device found. */ + dasd_set_target_state(device, DASD_STATE_NEW); + /* Now wait for the devices to come up. */ + wait_event(dasd_init_waitq, _wait_for_device(device)); +} + +/* + * SECTION: device operation (interrupt handler, start i/o, term i/o ...) + */ +#ifdef CONFIG_DASD_PROFILE + +struct dasd_profile_info_t dasd_global_profile; +unsigned int dasd_profile_level = DASD_PROFILE_OFF; + +/* + * Increments counter in global and local profiling structures. + */ +#define dasd_profile_counter(value, counter, device) \ +{ \ + int index; \ + for (index = 0; index < 31 && value >> (2+index); index++); \ + dasd_global_profile.counter[index]++; \ + device->profile.counter[index]++; \ +} + +/* + * Add profiling information for cqr before execution. + */ +static inline void +dasd_profile_start(struct dasd_device *device, struct dasd_ccw_req * cqr, + struct request *req) +{ + struct list_head *l; + unsigned int counter; + + if (dasd_profile_level != DASD_PROFILE_ON) + return; + + /* count the length of the chanq for statistics */ + counter = 0; + list_for_each(l, &device->ccw_queue) + if (++counter >= 31) + break; + dasd_global_profile.dasd_io_nr_req[counter]++; + device->profile.dasd_io_nr_req[counter]++; +} + +/* + * Add profiling information for cqr after execution. + */ +static inline void +dasd_profile_end(struct dasd_device *device, struct dasd_ccw_req * cqr, + struct request *req) +{ + long strtime, irqtime, endtime, tottime; /* in microseconds */ + long tottimeps, sectors; + + if (dasd_profile_level != DASD_PROFILE_ON) + return; + + sectors = req->nr_sectors; + if (!cqr->buildclk || !cqr->startclk || + !cqr->stopclk || !cqr->endclk || + !sectors) + return; + + strtime = ((cqr->startclk - cqr->buildclk) >> 12); + irqtime = ((cqr->stopclk - cqr->startclk) >> 12); + endtime = ((cqr->endclk - cqr->stopclk) >> 12); + tottime = ((cqr->endclk - cqr->buildclk) >> 12); + tottimeps = tottime / sectors; + + if (!dasd_global_profile.dasd_io_reqs) + memset(&dasd_global_profile, 0, + sizeof (struct dasd_profile_info_t)); + dasd_global_profile.dasd_io_reqs++; + dasd_global_profile.dasd_io_sects += sectors; + + if (!device->profile.dasd_io_reqs) + memset(&device->profile, 0, + sizeof (struct dasd_profile_info_t)); + device->profile.dasd_io_reqs++; + device->profile.dasd_io_sects += sectors; + + dasd_profile_counter(sectors, dasd_io_secs, device); + dasd_profile_counter(tottime, dasd_io_times, device); + dasd_profile_counter(tottimeps, dasd_io_timps, device); + dasd_profile_counter(strtime, dasd_io_time1, device); + dasd_profile_counter(irqtime, dasd_io_time2, device); + dasd_profile_counter(irqtime / sectors, dasd_io_time2ps, device); + dasd_profile_counter(endtime, dasd_io_time3, device); +} +#else +#define dasd_profile_start(device, cqr, req) do {} while (0) +#define dasd_profile_end(device, cqr, req) do {} while (0) +#endif /* CONFIG_DASD_PROFILE */ + +/* + * Allocate memory for a channel program with 'cplength' channel + * command words and 'datasize' additional space. There are two + * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed + * memory and 2) dasd_smalloc_request uses the static ccw memory + * that gets allocated for each device. + */ +struct dasd_ccw_req * +dasd_kmalloc_request(char *magic, int cplength, int datasize, + struct dasd_device * device) +{ + struct dasd_ccw_req *cqr; + + /* Sanity checks */ + if ( magic == NULL || datasize > PAGE_SIZE || + (cplength*sizeof(struct ccw1)) > PAGE_SIZE) + BUG(); + + cqr = kmalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC); + if (cqr == NULL) + return ERR_PTR(-ENOMEM); + memset(cqr, 0, sizeof(struct dasd_ccw_req)); + cqr->cpaddr = NULL; + if (cplength > 0) { + cqr->cpaddr = kmalloc(cplength*sizeof(struct ccw1), + GFP_ATOMIC | GFP_DMA); + if (cqr->cpaddr == NULL) { + kfree(cqr); + return ERR_PTR(-ENOMEM); + } + memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1)); + } + cqr->data = NULL; + if (datasize > 0) { + cqr->data = kmalloc(datasize, GFP_ATOMIC | GFP_DMA); + if (cqr->data == NULL) { + if (cqr->cpaddr != NULL) + kfree(cqr->cpaddr); + kfree(cqr); + return ERR_PTR(-ENOMEM); + } + memset(cqr->data, 0, datasize); + } + strncpy((char *) &cqr->magic, magic, 4); + ASCEBC((char *) &cqr->magic, 4); + set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags); + dasd_get_device(device); + return cqr; +} + +struct dasd_ccw_req * +dasd_smalloc_request(char *magic, int cplength, int datasize, + struct dasd_device * device) +{ + unsigned long flags; + struct dasd_ccw_req *cqr; + char *data; + int size; + + /* Sanity checks */ + if ( magic == NULL || datasize > PAGE_SIZE || + (cplength*sizeof(struct ccw1)) > PAGE_SIZE) + BUG(); + + size = (sizeof(struct dasd_ccw_req) + 7L) & -8L; + if (cplength > 0) + size += cplength * sizeof(struct ccw1); + if (datasize > 0) + size += datasize; + spin_lock_irqsave(&device->mem_lock, flags); + cqr = (struct dasd_ccw_req *) + dasd_alloc_chunk(&device->ccw_chunks, size); + spin_unlock_irqrestore(&device->mem_lock, flags); + if (cqr == NULL) + return ERR_PTR(-ENOMEM); + memset(cqr, 0, sizeof(struct dasd_ccw_req)); + data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L); + cqr->cpaddr = NULL; + if (cplength > 0) { + cqr->cpaddr = (struct ccw1 *) data; + data += cplength*sizeof(struct ccw1); + memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1)); + } + cqr->data = NULL; + if (datasize > 0) { + cqr->data = data; + memset(cqr->data, 0, datasize); + } + strncpy((char *) &cqr->magic, magic, 4); + ASCEBC((char *) &cqr->magic, 4); + set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags); + dasd_get_device(device); + return cqr; +} + +/* + * Free memory of a channel program. This function needs to free all the + * idal lists that might have been created by dasd_set_cda and the + * struct dasd_ccw_req itself. + */ +void +dasd_kfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device) +{ +#ifdef CONFIG_ARCH_S390X + struct ccw1 *ccw; + + /* Clear any idals used for the request. */ + ccw = cqr->cpaddr; + do { + clear_normalized_cda(ccw); + } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC)); +#endif + if (cqr->cpaddr != NULL) + kfree(cqr->cpaddr); + if (cqr->data != NULL) + kfree(cqr->data); + kfree(cqr); + dasd_put_device(device); +} + +void +dasd_sfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device) +{ + unsigned long flags; + + spin_lock_irqsave(&device->mem_lock, flags); + dasd_free_chunk(&device->ccw_chunks, cqr); + spin_unlock_irqrestore(&device->mem_lock, flags); + dasd_put_device(device); +} + +/* + * Check discipline magic in cqr. + */ +static inline int +dasd_check_cqr(struct dasd_ccw_req *cqr) +{ + struct dasd_device *device; + + if (cqr == NULL) + return -EINVAL; + device = cqr->device; + if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) { + DEV_MESSAGE(KERN_WARNING, device, + " dasd_ccw_req 0x%08x magic doesn't match" + " discipline 0x%08x", + cqr->magic, + *(unsigned int *) device->discipline->name); + return -EINVAL; + } + return 0; +} + +/* + * Terminate the current i/o and set the request to clear_pending. + * Timer keeps device runnig. + * ccw_device_clear can fail if the i/o subsystem + * is in a bad mood. + */ +int +dasd_term_IO(struct dasd_ccw_req * cqr) +{ + struct dasd_device *device; + int retries, rc; + + /* Check the cqr */ + rc = dasd_check_cqr(cqr); + if (rc) + return rc; + retries = 0; + device = (struct dasd_device *) cqr->device; + while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) { + rc = ccw_device_clear(device->cdev, (long) cqr); + switch (rc) { + case 0: /* termination successful */ + if (cqr->retries > 0) { + cqr->retries--; + cqr->status = DASD_CQR_CLEAR; + } else + cqr->status = DASD_CQR_FAILED; + cqr->stopclk = get_clock(); + DBF_DEV_EVENT(DBF_DEBUG, device, + "terminate cqr %p successful", + cqr); + break; + case -ENODEV: + DBF_DEV_EVENT(DBF_ERR, device, "%s", + "device gone, retry"); + break; + case -EIO: + DBF_DEV_EVENT(DBF_ERR, device, "%s", + "I/O error, retry"); + break; + case -EINVAL: + case -EBUSY: + DBF_DEV_EVENT(DBF_ERR, device, "%s", + "device busy, retry later"); + break; + default: + DEV_MESSAGE(KERN_ERR, device, + "line %d unknown RC=%d, please " + "report to linux390@de.ibm.com", + __LINE__, rc); + BUG(); + break; + } + retries++; + } + dasd_schedule_bh(device); + return rc; +} + +/* + * Start the i/o. This start_IO can fail if the channel is really busy. + * In that case set up a timer to start the request later. + */ +int +dasd_start_IO(struct dasd_ccw_req * cqr) +{ + struct dasd_device *device; + int rc; + + /* Check the cqr */ + rc = dasd_check_cqr(cqr); + if (rc) + return rc; + device = (struct dasd_device *) cqr->device; + if (cqr->retries < 0) { + DEV_MESSAGE(KERN_DEBUG, device, + "start_IO: request %p (%02x/%i) - no retry left.", + cqr, cqr->status, cqr->retries); + cqr->status = DASD_CQR_FAILED; + return -EIO; + } + cqr->startclk = get_clock(); + cqr->starttime = jiffies; + cqr->retries--; + rc = ccw_device_start(device->cdev, cqr->cpaddr, (long) cqr, + cqr->lpm, 0); + switch (rc) { + case 0: + cqr->status = DASD_CQR_IN_IO; + DBF_DEV_EVENT(DBF_DEBUG, device, + "start_IO: request %p started successful", + cqr); + break; + case -EBUSY: + DBF_DEV_EVENT(DBF_ERR, device, "%s", + "start_IO: device busy, retry later"); + break; + case -ETIMEDOUT: + DBF_DEV_EVENT(DBF_ERR, device, "%s", + "start_IO: request timeout, retry later"); + break; + case -EACCES: + /* -EACCES indicates that the request used only a + * subset of the available pathes and all these + * pathes are gone. + * Do a retry with all available pathes. + */ + cqr->lpm = LPM_ANYPATH; + DBF_DEV_EVENT(DBF_ERR, device, "%s", + "start_IO: selected pathes gone," + " retry on all pathes"); + break; + case -ENODEV: + case -EIO: + DBF_DEV_EVENT(DBF_ERR, device, "%s", + "start_IO: device gone, retry"); + break; + default: + DEV_MESSAGE(KERN_ERR, device, + "line %d unknown RC=%d, please report" + " to linux390@de.ibm.com", __LINE__, rc); + BUG(); + break; + } + return rc; +} + +/* + * Timeout function for dasd devices. This is used for different purposes + * 1) missing interrupt handler for normal operation + * 2) delayed start of request where start_IO failed with -EBUSY + * 3) timeout for missing state change interrupts + * The head of the ccw queue will have status DASD_CQR_IN_IO for 1), + * DASD_CQR_QUEUED for 2) and 3). + */ +static void +dasd_timeout_device(unsigned long ptr) +{ + unsigned long flags; + struct dasd_device *device; + + device = (struct dasd_device *) ptr; + spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); + /* re-activate request queue */ + device->stopped &= ~DASD_STOPPED_PENDING; + spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); + dasd_schedule_bh(device); +} + +/* + * Setup timeout for a device in jiffies. + */ +void +dasd_set_timer(struct dasd_device *device, int expires) +{ + if (expires == 0) { + if (timer_pending(&device->timer)) + del_timer(&device->timer); + return; + } + if (timer_pending(&device->timer)) { + if (mod_timer(&device->timer, jiffies + expires)) + return; + } + device->timer.function = dasd_timeout_device; + device->timer.data = (unsigned long) device; + device->timer.expires = jiffies + expires; + add_timer(&device->timer); +} + +/* + * Clear timeout for a device. + */ +void +dasd_clear_timer(struct dasd_device *device) +{ + if (timer_pending(&device->timer)) + del_timer(&device->timer); +} + +static void +dasd_handle_killed_request(struct ccw_device *cdev, unsigned long intparm) +{ + struct dasd_ccw_req *cqr; + struct dasd_device *device; + + cqr = (struct dasd_ccw_req *) intparm; + if (cqr->status != DASD_CQR_IN_IO) { + MESSAGE(KERN_DEBUG, + "invalid status in handle_killed_request: " + "bus_id %s, status %02x", + cdev->dev.bus_id, cqr->status); + return; + } + + device = (struct dasd_device *) cqr->device; + if (device == NULL || + device != dasd_device_from_cdev(cdev) || + strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) { + MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s", + cdev->dev.bus_id); + return; + } + + /* Schedule request to be retried. */ + cqr->status = DASD_CQR_QUEUED; + + dasd_clear_timer(device); + dasd_schedule_bh(device); + dasd_put_device(device); +} + +static void +dasd_handle_state_change_pending(struct dasd_device *device) +{ + struct dasd_ccw_req *cqr; + struct list_head *l, *n; + + device->stopped &= ~DASD_STOPPED_PENDING; + + /* restart all 'running' IO on queue */ + list_for_each_safe(l, n, &device->ccw_queue) { + cqr = list_entry(l, struct dasd_ccw_req, list); + if (cqr->status == DASD_CQR_IN_IO) { + cqr->status = DASD_CQR_QUEUED; + } + } + dasd_clear_timer(device); + dasd_schedule_bh(device); +} + +/* + * Interrupt handler for "normal" ssch-io based dasd devices. + */ +void +dasd_int_handler(struct ccw_device *cdev, unsigned long intparm, + struct irb *irb) +{ + struct dasd_ccw_req *cqr, *next; + struct dasd_device *device; + unsigned long long now; + int expires; + dasd_era_t era; + char mask; + + if (IS_ERR(irb)) { + switch (PTR_ERR(irb)) { + case -EIO: + dasd_handle_killed_request(cdev, intparm); + break; + case -ETIMEDOUT: + printk(KERN_WARNING"%s(%s): request timed out\n", + __FUNCTION__, cdev->dev.bus_id); + //FIXME - dasd uses own timeout interface... + break; + default: + printk(KERN_WARNING"%s(%s): unknown error %ld\n", + __FUNCTION__, cdev->dev.bus_id, PTR_ERR(irb)); + } + return; + } + + now = get_clock(); + + DBF_EVENT(DBF_ERR, "Interrupt: bus_id %s CS/DS %04x ip %08x", + cdev->dev.bus_id, ((irb->scsw.cstat<<8)|irb->scsw.dstat), + (unsigned int) intparm); + + /* first of all check for state change pending interrupt */ + mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP; + if ((irb->scsw.dstat & mask) == mask) { + device = dasd_device_from_cdev(cdev); + if (!IS_ERR(device)) { + dasd_handle_state_change_pending(device); + dasd_put_device(device); + } + return; + } + + cqr = (struct dasd_ccw_req *) intparm; + + /* check for unsolicited interrupts */ + if (cqr == NULL) { + MESSAGE(KERN_DEBUG, + "unsolicited interrupt received: bus_id %s", + cdev->dev.bus_id); + return; + } + + device = (struct dasd_device *) cqr->device; + if (device == NULL || + strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) { + MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s", + cdev->dev.bus_id); + return; + } + + /* Check for clear pending */ + if (cqr->status == DASD_CQR_CLEAR && + irb->scsw.fctl & SCSW_FCTL_CLEAR_FUNC) { + cqr->status = DASD_CQR_QUEUED; + dasd_clear_timer(device); + dasd_schedule_bh(device); + return; + } + + /* check status - the request might have been killed by dyn detach */ + if (cqr->status != DASD_CQR_IN_IO) { + MESSAGE(KERN_DEBUG, + "invalid status: bus_id %s, status %02x", + cdev->dev.bus_id, cqr->status); + return; + } + DBF_DEV_EVENT(DBF_DEBUG, device, "Int: CS/DS 0x%04x for cqr %p", + ((irb->scsw.cstat << 8) | irb->scsw.dstat), cqr); + + /* Find out the appropriate era_action. */ + if (irb->scsw.fctl & SCSW_FCTL_HALT_FUNC) + era = dasd_era_fatal; + else if (irb->scsw.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) && + irb->scsw.cstat == 0 && + !irb->esw.esw0.erw.cons) + era = dasd_era_none; + else if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) + era = dasd_era_fatal; /* don't recover this request */ + else if (irb->esw.esw0.erw.cons) + era = device->discipline->examine_error(cqr, irb); + else + era = dasd_era_recover; + + DBF_DEV_EVENT(DBF_DEBUG, device, "era_code %d", era); + expires = 0; + if (era == dasd_era_none) { + cqr->status = DASD_CQR_DONE; + cqr->stopclk = now; + /* Start first request on queue if possible -> fast_io. */ + if (cqr->list.next != &device->ccw_queue) { + next = list_entry(cqr->list.next, + struct dasd_ccw_req, list); + if ((next->status == DASD_CQR_QUEUED) && + (!device->stopped)) { + if (device->discipline->start_IO(next) == 0) + expires = next->expires; + else + DEV_MESSAGE(KERN_DEBUG, device, "%s", + "Interrupt fastpath " + "failed!"); + } + } + } else { /* error */ + memcpy(&cqr->irb, irb, sizeof (struct irb)); +#ifdef ERP_DEBUG + /* dump sense data */ + dasd_log_sense(cqr, irb); +#endif + switch (era) { + case dasd_era_fatal: + cqr->status = DASD_CQR_FAILED; + cqr->stopclk = now; + break; + case dasd_era_recover: + cqr->status = DASD_CQR_ERROR; + break; + default: + BUG(); + } + } + if (expires != 0) + dasd_set_timer(device, expires); + else + dasd_clear_timer(device); + dasd_schedule_bh(device); +} + +/* + * posts the buffer_cache about a finalized request + */ +static inline void +dasd_end_request(struct request *req, int uptodate) +{ + if (end_that_request_first(req, uptodate, req->hard_nr_sectors)) + BUG(); + add_disk_randomness(req->rq_disk); + end_that_request_last(req); +} + +/* + * Process finished error recovery ccw. + */ +static inline void +__dasd_process_erp(struct dasd_device *device, struct dasd_ccw_req *cqr) +{ + dasd_erp_fn_t erp_fn; + + if (cqr->status == DASD_CQR_DONE) + DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful"); + else + DEV_MESSAGE(KERN_ERR, device, "%s", "ERP unsuccessful"); + erp_fn = device->discipline->erp_postaction(cqr); + erp_fn(cqr); +} + +/* + * Process ccw request queue. + */ +static inline void +__dasd_process_ccw_queue(struct dasd_device * device, + struct list_head *final_queue) +{ + struct list_head *l, *n; + struct dasd_ccw_req *cqr; + dasd_erp_fn_t erp_fn; + +restart: + /* Process request with final status. */ + list_for_each_safe(l, n, &device->ccw_queue) { + cqr = list_entry(l, struct dasd_ccw_req, list); + /* Stop list processing at the first non-final request. */ + if (cqr->status != DASD_CQR_DONE && + cqr->status != DASD_CQR_FAILED && + cqr->status != DASD_CQR_ERROR) + break; + /* Process requests with DASD_CQR_ERROR */ + if (cqr->status == DASD_CQR_ERROR) { + if (cqr->irb.scsw.fctl & SCSW_FCTL_HALT_FUNC) { + cqr->status = DASD_CQR_FAILED; + cqr->stopclk = get_clock(); + } else { + if (cqr->irb.esw.esw0.erw.cons) { + erp_fn = device->discipline-> + erp_action(cqr); + erp_fn(cqr); + } else + dasd_default_erp_action(cqr); + } + goto restart; + } + /* Process finished ERP request. */ + if (cqr->refers) { + __dasd_process_erp(device, cqr); + goto restart; + } + + /* Rechain finished requests to final queue */ + cqr->endclk = get_clock(); + list_move_tail(&cqr->list, final_queue); + } +} + +static void +dasd_end_request_cb(struct dasd_ccw_req * cqr, void *data) +{ + struct request *req; + struct dasd_device *device; + int status; + + req = (struct request *) data; + device = cqr->device; + dasd_profile_end(device, cqr, req); + status = cqr->device->discipline->free_cp(cqr,req); + spin_lock_irq(&device->request_queue_lock); + dasd_end_request(req, status); + spin_unlock_irq(&device->request_queue_lock); +} + + +/* + * Fetch requests from the block device queue. + */ +static inline void +__dasd_process_blk_queue(struct dasd_device * device) +{ + request_queue_t *queue; + struct request *req; + struct dasd_ccw_req *cqr; + int nr_queued; + + queue = device->request_queue; + /* No queue ? Then there is nothing to do. */ + if (queue == NULL) + return; + + /* + * We requeue request from the block device queue to the ccw + * queue only in two states. In state DASD_STATE_READY the + * partition detection is done and we need to requeue requests + * for that. State DASD_STATE_ONLINE is normal block device + * operation. + */ + if (device->state != DASD_STATE_READY && + device->state != DASD_STATE_ONLINE) + return; + nr_queued = 0; + /* Now we try to fetch requests from the request queue */ + list_for_each_entry(cqr, &device->ccw_queue, list) + if (cqr->status == DASD_CQR_QUEUED) + nr_queued++; + while (!blk_queue_plugged(queue) && + elv_next_request(queue) && + nr_queued < DASD_CHANQ_MAX_SIZE) { + req = elv_next_request(queue); + if (test_bit(DASD_FLAG_RO, &device->flags) && + rq_data_dir(req) == WRITE) { + DBF_DEV_EVENT(DBF_ERR, device, + "Rejecting write request %p", + req); + blkdev_dequeue_request(req); + dasd_end_request(req, 0); + continue; + } + if (device->stopped & DASD_STOPPED_DC_EIO) { + blkdev_dequeue_request(req); + dasd_end_request(req, 0); + continue; + } + cqr = device->discipline->build_cp(device, req); + if (IS_ERR(cqr)) { + if (PTR_ERR(cqr) == -ENOMEM) + break; /* terminate request queue loop */ + DBF_DEV_EVENT(DBF_ERR, device, + "CCW creation failed (rc=%ld) " + "on request %p", + PTR_ERR(cqr), req); + blkdev_dequeue_request(req); + dasd_end_request(req, 0); + continue; + } + cqr->callback = dasd_end_request_cb; + cqr->callback_data = (void *) req; + cqr->status = DASD_CQR_QUEUED; + blkdev_dequeue_request(req); + list_add_tail(&cqr->list, &device->ccw_queue); + dasd_profile_start(device, cqr, req); + nr_queued++; + } +} + +/* + * Take a look at the first request on the ccw queue and check + * if it reached its expire time. If so, terminate the IO. + */ +static inline void +__dasd_check_expire(struct dasd_device * device) +{ + struct dasd_ccw_req *cqr; + + if (list_empty(&device->ccw_queue)) + return; + cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list); + if (cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) { + if (time_after_eq(jiffies, cqr->expires + cqr->starttime)) { + if (device->discipline->term_IO(cqr) != 0) + /* Hmpf, try again in 1/10 sec */ + dasd_set_timer(device, 10); + } + } +} + +/* + * Take a look at the first request on the ccw queue and check + * if it needs to be started. + */ +static inline void +__dasd_start_head(struct dasd_device * device) +{ + struct dasd_ccw_req *cqr; + int rc; + + if (list_empty(&device->ccw_queue)) + return; + cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list); + if ((cqr->status == DASD_CQR_QUEUED) && + (!device->stopped)) { + /* try to start the first I/O that can be started */ + rc = device->discipline->start_IO(cqr); + if (rc == 0) + dasd_set_timer(device, cqr->expires); + else if (rc == -EACCES) { + dasd_schedule_bh(device); + } else + /* Hmpf, try again in 1/2 sec */ + dasd_set_timer(device, 50); + } +} + +/* + * Remove requests from the ccw queue. + */ +static void +dasd_flush_ccw_queue(struct dasd_device * device, int all) +{ + struct list_head flush_queue; + struct list_head *l, *n; + struct dasd_ccw_req *cqr; + + INIT_LIST_HEAD(&flush_queue); + spin_lock_irq(get_ccwdev_lock(device->cdev)); + list_for_each_safe(l, n, &device->ccw_queue) { + cqr = list_entry(l, struct dasd_ccw_req, list); + /* Flush all request or only block device requests? */ + if (all == 0 && cqr->callback == dasd_end_request_cb) + continue; + if (cqr->status == DASD_CQR_IN_IO) + device->discipline->term_IO(cqr); + if (cqr->status != DASD_CQR_DONE || + cqr->status != DASD_CQR_FAILED) { + cqr->status = DASD_CQR_FAILED; + cqr->stopclk = get_clock(); + } + /* Process finished ERP request. */ + if (cqr->refers) { + __dasd_process_erp(device, cqr); + continue; + } + /* Rechain request on device request queue */ + cqr->endclk = get_clock(); + list_move_tail(&cqr->list, &flush_queue); + } + spin_unlock_irq(get_ccwdev_lock(device->cdev)); + /* Now call the callback function of flushed requests */ + list_for_each_safe(l, n, &flush_queue) { + cqr = list_entry(l, struct dasd_ccw_req, list); + if (cqr->callback != NULL) + (cqr->callback)(cqr, cqr->callback_data); + } +} + +/* + * Acquire the device lock and process queues for the device. + */ +static void +dasd_tasklet(struct dasd_device * device) +{ + struct list_head final_queue; + struct list_head *l, *n; + struct dasd_ccw_req *cqr; + + atomic_set (&device->tasklet_scheduled, 0); + INIT_LIST_HEAD(&final_queue); + spin_lock_irq(get_ccwdev_lock(device->cdev)); + /* Check expire time of first request on the ccw queue. */ + __dasd_check_expire(device); + /* Finish off requests on ccw queue */ + __dasd_process_ccw_queue(device, &final_queue); + spin_unlock_irq(get_ccwdev_lock(device->cdev)); + /* Now call the callback function of requests with final status */ + list_for_each_safe(l, n, &final_queue) { + cqr = list_entry(l, struct dasd_ccw_req, list); + list_del(&cqr->list); + if (cqr->callback != NULL) + (cqr->callback)(cqr, cqr->callback_data); + } + spin_lock_irq(&device->request_queue_lock); + spin_lock(get_ccwdev_lock(device->cdev)); + /* Get new request from the block device request queue */ + __dasd_process_blk_queue(device); + /* Now check if the head of the ccw queue needs to be started. */ + __dasd_start_head(device); + spin_unlock(get_ccwdev_lock(device->cdev)); + spin_unlock_irq(&device->request_queue_lock); + dasd_put_device(device); +} + +/* + * Schedules a call to dasd_tasklet over the device tasklet. + */ +void +dasd_schedule_bh(struct dasd_device * device) +{ + /* Protect against rescheduling. */ + if (atomic_compare_and_swap (0, 1, &device->tasklet_scheduled)) + return; + dasd_get_device(device); + tasklet_hi_schedule(&device->tasklet); +} + +/* + * Queue a request to the head of the ccw_queue. Start the I/O if + * possible. + */ +void +dasd_add_request_head(struct dasd_ccw_req *req) +{ + struct dasd_device *device; + unsigned long flags; + + device = req->device; + spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); + req->status = DASD_CQR_QUEUED; + req->device = device; + list_add(&req->list, &device->ccw_queue); + /* let the bh start the request to keep them in order */ + dasd_schedule_bh(device); + spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); +} + +/* + * Queue a request to the tail of the ccw_queue. Start the I/O if + * possible. + */ +void +dasd_add_request_tail(struct dasd_ccw_req *req) +{ + struct dasd_device *device; + unsigned long flags; + + device = req->device; + spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); + req->status = DASD_CQR_QUEUED; + req->device = device; + list_add_tail(&req->list, &device->ccw_queue); + /* let the bh start the request to keep them in order */ + dasd_schedule_bh(device); + spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); +} + +/* + * Wakeup callback. + */ +static void +dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data) +{ + wake_up((wait_queue_head_t *) data); +} + +static inline int +_wait_for_wakeup(struct dasd_ccw_req *cqr) +{ + struct dasd_device *device; + int rc; + + device = cqr->device; + spin_lock_irq(get_ccwdev_lock(device->cdev)); + rc = cqr->status == DASD_CQR_DONE || cqr->status == DASD_CQR_FAILED; + spin_unlock_irq(get_ccwdev_lock(device->cdev)); + return rc; +} + +/* + * Attempts to start a special ccw queue and waits for its completion. + */ +int +dasd_sleep_on(struct dasd_ccw_req * cqr) +{ + wait_queue_head_t wait_q; + struct dasd_device *device; + int rc; + + device = cqr->device; + spin_lock_irq(get_ccwdev_lock(device->cdev)); + + init_waitqueue_head (&wait_q); + cqr->callback = dasd_wakeup_cb; + cqr->callback_data = (void *) &wait_q; + cqr->status = DASD_CQR_QUEUED; + list_add_tail(&cqr->list, &device->ccw_queue); + + /* let the bh start the request to keep them in order */ + dasd_schedule_bh(device); + + spin_unlock_irq(get_ccwdev_lock(device->cdev)); + + wait_event(wait_q, _wait_for_wakeup(cqr)); + + /* Request status is either done or failed. */ + rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0; + return rc; +} + +/* + * Attempts to start a special ccw queue and wait interruptible + * for its completion. + */ +int +dasd_sleep_on_interruptible(struct dasd_ccw_req * cqr) +{ + wait_queue_head_t wait_q; + struct dasd_device *device; + int rc, finished; + + device = cqr->device; + spin_lock_irq(get_ccwdev_lock(device->cdev)); + + init_waitqueue_head (&wait_q); + cqr->callback = dasd_wakeup_cb; + cqr->callback_data = (void *) &wait_q; + cqr->status = DASD_CQR_QUEUED; + list_add_tail(&cqr->list, &device->ccw_queue); + + /* let the bh start the request to keep them in order */ + dasd_schedule_bh(device); + spin_unlock_irq(get_ccwdev_lock(device->cdev)); + + finished = 0; + while (!finished) { + rc = wait_event_interruptible(wait_q, _wait_for_wakeup(cqr)); + if (rc != -ERESTARTSYS) { + /* Request status is either done or failed. */ + rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0; + break; + } + spin_lock_irq(get_ccwdev_lock(device->cdev)); + if (cqr->status == DASD_CQR_IN_IO && + device->discipline->term_IO(cqr) == 0) { + list_del(&cqr->list); + finished = 1; + } + spin_unlock_irq(get_ccwdev_lock(device->cdev)); + } + return rc; +} + +/* + * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock + * for eckd devices) the currently running request has to be terminated + * and be put back to status queued, before the special request is added + * to the head of the queue. Then the special request is waited on normally. + */ +static inline int +_dasd_term_running_cqr(struct dasd_device *device) +{ + struct dasd_ccw_req *cqr; + int rc; + + if (list_empty(&device->ccw_queue)) + return 0; + cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list); + rc = device->discipline->term_IO(cqr); + if (rc == 0) { + /* termination successful */ + cqr->status = DASD_CQR_QUEUED; + cqr->startclk = cqr->stopclk = 0; + cqr->starttime = 0; + } + return rc; +} + +int +dasd_sleep_on_immediatly(struct dasd_ccw_req * cqr) +{ + wait_queue_head_t wait_q; + struct dasd_device *device; + int rc; + + device = cqr->device; + spin_lock_irq(get_ccwdev_lock(device->cdev)); + rc = _dasd_term_running_cqr(device); + if (rc) { + spin_unlock_irq(get_ccwdev_lock(device->cdev)); + return rc; + } + + init_waitqueue_head (&wait_q); + cqr->callback = dasd_wakeup_cb; + cqr->callback_data = (void *) &wait_q; + cqr->status = DASD_CQR_QUEUED; + list_add(&cqr->list, &device->ccw_queue); + + /* let the bh start the request to keep them in order */ + dasd_schedule_bh(device); + + spin_unlock_irq(get_ccwdev_lock(device->cdev)); + + wait_event(wait_q, _wait_for_wakeup(cqr)); + + /* Request status is either done or failed. */ + rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0; + return rc; +} + +/* + * Cancels a request that was started with dasd_sleep_on_req. + * This is useful to timeout requests. The request will be + * terminated if it is currently in i/o. + * Returns 1 if the request has been terminated. + */ +int +dasd_cancel_req(struct dasd_ccw_req *cqr) +{ + struct dasd_device *device = cqr->device; + unsigned long flags; + int rc; + + rc = 0; + spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags); + switch (cqr->status) { + case DASD_CQR_QUEUED: + /* request was not started - just set to failed */ + cqr->status = DASD_CQR_FAILED; + break; + case DASD_CQR_IN_IO: + /* request in IO - terminate IO and release again */ + if (device->discipline->term_IO(cqr) != 0) + /* what to do if unable to terminate ?????? + e.g. not _IN_IO */ + cqr->status = DASD_CQR_FAILED; + cqr->stopclk = get_clock(); + rc = 1; + break; + case DASD_CQR_DONE: + case DASD_CQR_FAILED: + /* already finished - do nothing */ + break; + default: + DEV_MESSAGE(KERN_ALERT, device, + "invalid status %02x in request", + cqr->status); + BUG(); + + } + spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags); + dasd_schedule_bh(device); + return rc; +} + +/* + * SECTION: Block device operations (request queue, partitions, open, release). + */ + +/* + * Dasd request queue function. Called from ll_rw_blk.c + */ +static void +do_dasd_request(request_queue_t * queue) +{ + struct dasd_device *device; + + device = (struct dasd_device *) queue->queuedata; + spin_lock(get_ccwdev_lock(device->cdev)); + /* Get new request from the block device request queue */ + __dasd_process_blk_queue(device); + /* Now check if the head of the ccw queue needs to be started. */ + __dasd_start_head(device); + spin_unlock(get_ccwdev_lock(device->cdev)); +} + +/* + * Allocate and initialize request queue and default I/O scheduler. + */ +static int +dasd_alloc_queue(struct dasd_device * device) +{ + int rc; + + device->request_queue = blk_init_queue(do_dasd_request, + &device->request_queue_lock); + if (device->request_queue == NULL) + return -ENOMEM; + + device->request_queue->queuedata = device; + + elevator_exit(device->request_queue->elevator); + rc = elevator_init(device->request_queue, "deadline"); + if (rc) { + blk_cleanup_queue(device->request_queue); + return rc; + } + return 0; +} + +/* + * Allocate and initialize request queue. + */ +static void +dasd_setup_queue(struct dasd_device * device) +{ + int max; + + blk_queue_hardsect_size(device->request_queue, device->bp_block); + max = device->discipline->max_blocks << device->s2b_shift; + blk_queue_max_sectors(device->request_queue, max); + blk_queue_max_phys_segments(device->request_queue, -1L); + blk_queue_max_hw_segments(device->request_queue, -1L); + blk_queue_max_segment_size(device->request_queue, -1L); + blk_queue_segment_boundary(device->request_queue, -1L); +} + +/* + * Deactivate and free request queue. + */ +static void +dasd_free_queue(struct dasd_device * device) +{ + if (device->request_queue) { + blk_cleanup_queue(device->request_queue); + device->request_queue = NULL; + } +} + +/* + * Flush request on the request queue. + */ +static void +dasd_flush_request_queue(struct dasd_device * device) +{ + struct request *req; + + if (!device->request_queue) + return; + + spin_lock_irq(&device->request_queue_lock); + while (!list_empty(&device->request_queue->queue_head)) { + req = elv_next_request(device->request_queue); + if (req == NULL) + break; + dasd_end_request(req, 0); + blkdev_dequeue_request(req); + } + spin_unlock_irq(&device->request_queue_lock); +} + +static int +dasd_open(struct inode *inp, struct file *filp) +{ + struct gendisk *disk = inp->i_bdev->bd_disk; + struct dasd_device *device = disk->private_data; + int rc; + + atomic_inc(&device->open_count); + if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) { + rc = -ENODEV; + goto unlock; + } + + if (!try_module_get(device->discipline->owner)) { + rc = -EINVAL; + goto unlock; + } + + if (dasd_probeonly) { + DEV_MESSAGE(KERN_INFO, device, "%s", + "No access to device due to probeonly mode"); + rc = -EPERM; + goto out; + } + + if (device->state < DASD_STATE_BASIC) { + DBF_DEV_EVENT(DBF_ERR, device, " %s", + " Cannot open unrecognized device"); + rc = -ENODEV; + goto out; + } + + return 0; + +out: + module_put(device->discipline->owner); +unlock: + atomic_dec(&device->open_count); + return rc; +} + +static int +dasd_release(struct inode *inp, struct file *filp) +{ + struct gendisk *disk = inp->i_bdev->bd_disk; + struct dasd_device *device = disk->private_data; + + atomic_dec(&device->open_count); + module_put(device->discipline->owner); + return 0; +} + +struct block_device_operations +dasd_device_operations = { + .owner = THIS_MODULE, + .open = dasd_open, + .release = dasd_release, + .ioctl = dasd_ioctl, +}; + + +static void +dasd_exit(void) +{ +#ifdef CONFIG_PROC_FS + dasd_proc_exit(); +#endif + dasd_ioctl_exit(); + dasd_gendisk_exit(); + dasd_devmap_exit(); + devfs_remove("dasd"); + if (dasd_debug_area != NULL) { + debug_unregister(dasd_debug_area); + dasd_debug_area = NULL; + } +} + +/* + * SECTION: common functions for ccw_driver use + */ + +/* initial attempt at a probe function. this can be simplified once + * the other detection code is gone */ +int +dasd_generic_probe (struct ccw_device *cdev, + struct dasd_discipline *discipline) +{ + int ret; + + ret = dasd_add_sysfs_files(cdev); + if (ret) { + printk(KERN_WARNING + "dasd_generic_probe: could not add sysfs entries " + "for %s\n", cdev->dev.bus_id); + } + + cdev->handler = &dasd_int_handler; + + return ret; +} + +/* this will one day be called from a global not_oper handler. + * It is also used by driver_unregister during module unload */ +void +dasd_generic_remove (struct ccw_device *cdev) +{ + struct dasd_device *device; + + dasd_remove_sysfs_files(cdev); + device = dasd_device_from_cdev(cdev); + if (IS_ERR(device)) + return; + if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) { + /* Already doing offline processing */ + dasd_put_device(device); + return; + } + /* + * This device is removed unconditionally. Set offline + * flag to prevent dasd_open from opening it while it is + * no quite down yet. + */ + dasd_set_target_state(device, DASD_STATE_NEW); + /* dasd_delete_device destroys the device reference. */ + dasd_delete_device(device); +} + +/* activate a device. This is called from dasd_{eckd,fba}_probe() when either + * the device is detected for the first time and is supposed to be used + * or the user has started activation through sysfs */ +int +dasd_generic_set_online (struct ccw_device *cdev, + struct dasd_discipline *discipline) + +{ + struct dasd_device *device; + int rc; + + device = dasd_create_device(cdev); + if (IS_ERR(device)) + return PTR_ERR(device); + + if (test_bit(DASD_FLAG_USE_DIAG, &device->flags)) { + if (!dasd_diag_discipline_pointer) { + printk (KERN_WARNING + "dasd_generic couldn't online device %s " + "- discipline DIAG not available\n", + cdev->dev.bus_id); + dasd_delete_device(device); + return -ENODEV; + } + discipline = dasd_diag_discipline_pointer; + } + device->discipline = discipline; + + rc = discipline->check_device(device); + if (rc) { + printk (KERN_WARNING + "dasd_generic couldn't online device %s " + "with discipline %s rc=%i\n", + cdev->dev.bus_id, discipline->name, rc); + dasd_delete_device(device); + return rc; + } + + dasd_set_target_state(device, DASD_STATE_ONLINE); + if (device->state <= DASD_STATE_KNOWN) { + printk (KERN_WARNING + "dasd_generic discipline not found for %s\n", + cdev->dev.bus_id); + rc = -ENODEV; + dasd_set_target_state(device, DASD_STATE_NEW); + dasd_delete_device(device); + } else + pr_debug("dasd_generic device %s found\n", + cdev->dev.bus_id); + + /* FIXME: we have to wait for the root device but we don't want + * to wait for each single device but for all at once. */ + wait_event(dasd_init_waitq, _wait_for_device(device)); + + dasd_put_device(device); + + return rc; +} + +int +dasd_generic_set_offline (struct ccw_device *cdev) +{ + struct dasd_device *device; + int max_count; + + device = dasd_device_from_cdev(cdev); + if (IS_ERR(device)) + return PTR_ERR(device); + if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) { + /* Already doing offline processing */ + dasd_put_device(device); + return 0; + } + /* + * We must make sure that this device is currently not in use. + * The open_count is increased for every opener, that includes + * the blkdev_get in dasd_scan_partitions. We are only interested + * in the other openers. + */ + max_count = device->bdev ? 0 : -1; + if (atomic_read(&device->open_count) > max_count) { + printk (KERN_WARNING "Can't offline dasd device with open" + " count = %i.\n", + atomic_read(&device->open_count)); + clear_bit(DASD_FLAG_OFFLINE, &device->flags); + dasd_put_device(device); + return -EBUSY; + } + dasd_set_target_state(device, DASD_STATE_NEW); + /* dasd_delete_device destroys the device reference. */ + dasd_delete_device(device); + + return 0; +} + +int +dasd_generic_notify(struct ccw_device *cdev, int event) +{ + struct dasd_device *device; + struct dasd_ccw_req *cqr; + unsigned long flags; + int ret; + + device = dasd_device_from_cdev(cdev); + if (IS_ERR(device)) + return 0; + spin_lock_irqsave(get_ccwdev_lock(cdev), flags); + ret = 0; + switch (event) { + case CIO_GONE: + case CIO_NO_PATH: + if (device->state < DASD_STATE_BASIC) + break; + /* Device is active. We want to keep it. */ + if (test_bit(DASD_FLAG_DSC_ERROR, &device->flags)) { + list_for_each_entry(cqr, &device->ccw_queue, list) + if (cqr->status == DASD_CQR_IN_IO) + cqr->status = DASD_CQR_FAILED; + device->stopped |= DASD_STOPPED_DC_EIO; + dasd_schedule_bh(device); + } else { + list_for_each_entry(cqr, &device->ccw_queue, list) + if (cqr->status == DASD_CQR_IN_IO) { + cqr->status = DASD_CQR_QUEUED; + cqr->retries++; + } + device->stopped |= DASD_STOPPED_DC_WAIT; + dasd_set_timer(device, 0); + } + ret = 1; + break; + case CIO_OPER: + /* FIXME: add a sanity check. */ + device->stopped &= ~(DASD_STOPPED_DC_WAIT|DASD_STOPPED_DC_EIO); + dasd_schedule_bh(device); + ret = 1; + break; + } + spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags); + dasd_put_device(device); + return ret; +} + +/* + * Automatically online either all dasd devices (dasd_autodetect) or + * all devices specified with dasd= parameters. + */ +void +dasd_generic_auto_online (struct ccw_driver *dasd_discipline_driver) +{ + struct device_driver *drv; + struct device *d, *dev; + struct ccw_device *cdev; + + drv = get_driver(&dasd_discipline_driver->driver); + down_read(&drv->bus->subsys.rwsem); + dev = NULL; + list_for_each_entry(d, &drv->devices, driver_list) { + dev = get_device(d); + if (!dev) + continue; + cdev = to_ccwdev(dev); + if (dasd_autodetect || dasd_busid_known(cdev->dev.bus_id) == 0) + ccw_device_set_online(cdev); + put_device(dev); + } + up_read(&drv->bus->subsys.rwsem); + put_driver(drv); +} + +static int __init +dasd_init(void) +{ + int rc; + + init_waitqueue_head(&dasd_init_waitq); + + /* register 'common' DASD debug area, used for all DBF_XXX calls */ + dasd_debug_area = debug_register("dasd", 0, 2, 8 * sizeof (long)); + if (dasd_debug_area == NULL) { + rc = -ENOMEM; + goto failed; + } + debug_register_view(dasd_debug_area, &debug_sprintf_view); + debug_set_level(dasd_debug_area, DBF_EMERG); + + DBF_EVENT(DBF_EMERG, "%s", "debug area created"); + + dasd_diag_discipline_pointer = NULL; + + rc = devfs_mk_dir("dasd"); + if (rc) + goto failed; + rc = dasd_devmap_init(); + if (rc) + goto failed; + rc = dasd_gendisk_init(); + if (rc) + goto failed; + rc = dasd_parse(); + if (rc) + goto failed; + rc = dasd_ioctl_init(); + if (rc) + goto failed; +#ifdef CONFIG_PROC_FS + rc = dasd_proc_init(); + if (rc) + goto failed; +#endif + + return 0; +failed: + MESSAGE(KERN_INFO, "%s", "initialization not performed due to errors"); + dasd_exit(); + return rc; +} + +module_init(dasd_init); +module_exit(dasd_exit); + +EXPORT_SYMBOL(dasd_debug_area); +EXPORT_SYMBOL(dasd_diag_discipline_pointer); + +EXPORT_SYMBOL(dasd_add_request_head); +EXPORT_SYMBOL(dasd_add_request_tail); +EXPORT_SYMBOL(dasd_cancel_req); +EXPORT_SYMBOL(dasd_clear_timer); +EXPORT_SYMBOL(dasd_enable_device); +EXPORT_SYMBOL(dasd_int_handler); +EXPORT_SYMBOL(dasd_kfree_request); +EXPORT_SYMBOL(dasd_kick_device); +EXPORT_SYMBOL(dasd_kmalloc_request); +EXPORT_SYMBOL(dasd_schedule_bh); +EXPORT_SYMBOL(dasd_set_target_state); +EXPORT_SYMBOL(dasd_set_timer); +EXPORT_SYMBOL(dasd_sfree_request); +EXPORT_SYMBOL(dasd_sleep_on); +EXPORT_SYMBOL(dasd_sleep_on_immediatly); +EXPORT_SYMBOL(dasd_sleep_on_interruptible); +EXPORT_SYMBOL(dasd_smalloc_request); +EXPORT_SYMBOL(dasd_start_IO); +EXPORT_SYMBOL(dasd_term_IO); + +EXPORT_SYMBOL_GPL(dasd_generic_probe); +EXPORT_SYMBOL_GPL(dasd_generic_remove); +EXPORT_SYMBOL_GPL(dasd_generic_notify); +EXPORT_SYMBOL_GPL(dasd_generic_set_online); +EXPORT_SYMBOL_GPL(dasd_generic_set_offline); +EXPORT_SYMBOL_GPL(dasd_generic_auto_online); + +/* + * Overrides for Emacs so that we follow Linus's tabbing style. + * Emacs will notice this stuff at the end of the file and automatically + * adjust the settings for this buffer only. This must remain at the end + * of the file. + * --------------------------------------------------------------------------- + * Local variables: + * c-indent-level: 4 + * c-brace-imaginary-offset: 0 + * c-brace-offset: -4 + * c-argdecl-indent: 4 + * c-label-offset: -4 + * c-continued-statement-offset: 4 + * c-continued-brace-offset: 0 + * indent-tabs-mode: 1 + * tab-width: 8 + * End: + */ |
