/* * IDE I/O functions * * Basic PIO and command management functionality. * * This code was split off from ide.c. See ide.c for history and original * copyrights. * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2, or (at your option) any * later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * For the avoidance of doubt the "preferred form" of this code is one which * is in an open non patent encumbered format. Where cryptographic key signing * forms part of the process of creating an executable the information * including keys needed to generate an equivalently functional executable * are deemed to be part of the source code. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static int __ide_end_request(ide_drive_t *drive, struct request *rq, int uptodate, unsigned int nr_bytes, int dequeue) { int ret = 1; int error = 0; if (uptodate <= 0) error = uptodate ? uptodate : -EIO; /* * if failfast is set on a request, override number of sectors and * complete the whole request right now */ if (blk_noretry_request(rq) && error) nr_bytes = rq->hard_nr_sectors << 9; if (!blk_fs_request(rq) && error && !rq->errors) rq->errors = -EIO; /* * decide whether to reenable DMA -- 3 is a random magic for now, * if we DMA timeout more than 3 times, just stay in PIO */ if ((drive->dev_flags & IDE_DFLAG_DMA_PIO_RETRY) && drive->retry_pio <= 3) { drive->dev_flags &= ~IDE_DFLAG_DMA_PIO_RETRY; ide_dma_on(drive); } if (!blk_end_request(rq, error, nr_bytes)) ret = 0; if (ret == 0 && dequeue) drive->hwif->hwgroup->rq = NULL; return ret; } /** * ide_end_request - complete an IDE I/O * @drive: IDE device for the I/O * @uptodate: * @nr_sectors: number of sectors completed * * This is our end_request wrapper function. We complete the I/O * update random number input and dequeue the request, which if * it was tagged may be out of order. */ int ide_end_request (ide_drive_t *drive, int uptodate, int nr_sectors) { unsigned int nr_bytes = nr_sectors << 9; struct request *rq = drive->hwif->hwgroup->rq; if (!nr_bytes) { if (blk_pc_request(rq)) nr_bytes = rq->data_len; else nr_bytes = rq->hard_cur_sectors << 9; } return __ide_end_request(drive, rq, uptodate, nr_bytes, 1); } EXPORT_SYMBOL(ide_end_request); /** * ide_end_dequeued_request - complete an IDE I/O * @drive: IDE device for the I/O * @uptodate: * @nr_sectors: number of sectors completed * * Complete an I/O that is no longer on the request queue. This * typically occurs when we pull the request and issue a REQUEST_SENSE. * We must still finish the old request but we must not tamper with the * queue in the meantime. * * NOTE: This path does not handle barrier, but barrier is not supported * on ide-cd anyway. */ int ide_end_dequeued_request(ide_drive_t *drive, struct request *rq, int uptodate, int nr_sectors) { BUG_ON(!blk_rq_started(rq)); return __ide_end_request(drive, rq, uptodate, nr_sectors << 9, 0); } EXPORT_SYMBOL_GPL(ide_end_dequeued_request); /** * ide_end_drive_cmd - end an explicit drive command * @drive: command * @stat: status bits * @err: error bits * * Clean up after success/failure of an explicit drive command. * These get thrown onto the queue so they are synchronized with * real I/O operations on the drive. * * In LBA48 mode we have to read the register set twice to get * all the extra information out. */ void ide_end_drive_cmd (ide_drive_t *drive, u8 stat, u8 err) { ide_hwgroup_t *hwgroup = drive->hwif->hwgroup; struct request *rq = hwgroup->rq; if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) { ide_task_t *task = (ide_task_t *)rq->special; if (task) { struct ide_taskfile *tf = &task->tf; tf->error = err; tf->status = stat; drive->hwif->tp_ops->tf_read(drive, task); if (task->tf_flags & IDE_TFLAG_DYN) kfree(task); } } else if (blk_pm_request(rq)) { struct request_pm_state *pm = rq->data; ide_complete_power_step(drive, rq); if (pm->pm_step == IDE_PM_COMPLETED) ide_complete_pm_request(drive, rq); return; } hwgroup->rq = NULL; rq->errors = err; if (unlikely(blk_end_request(rq, (rq->errors ? -EIO : 0), blk_rq_bytes(rq)))) BUG(); } EXPORT_SYMBOL(ide_end_drive_cmd); static void ide_kill_rq(ide_drive_t *drive, struct request *rq) { if (rq->rq_disk) { ide_driver_t *drv; drv = *(ide_driver_t **)rq->rq_disk->private_data; drv->end_request(drive, 0, 0); } else ide_end_request(drive, 0, 0); } static ide_startstop_t ide_ata_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err) { ide_hwif_t *hwif = drive->hwif; if ((stat & ATA_BUSY) || ((stat & ATA_DF) && (drive->dev_flags & IDE_DFLAG_NOWERR) == 0)) { /* other bits are useless when BUSY */ rq->errors |= ERROR_RESET; } else if (stat & ATA_ERR) { /* err has different meaning on cdrom and tape */ if (err == ATA_ABORTED) { if ((drive->dev_flags & IDE_DFLAG_LBA) && /* some newer drives don't support ATA_CMD_INIT_DEV_PARAMS */ hwif->tp_ops->read_status(hwif) == ATA_CMD_INIT_DEV_PARAMS) return ide_stopped; } else if ((err & BAD_CRC) == BAD_CRC) { /* UDMA crc error, just retry the operation */ drive->crc_count++; } else if (err & (ATA_BBK | ATA_UNC)) { /* retries won't help these */ rq->errors = ERROR_MAX; } else if (err & ATA_TRK0NF) { /* help it find track zero */ rq->errors |= ERROR_RECAL; } } if ((stat & ATA_DRQ) && rq_data_dir(rq) == READ && (hwif->host_flags & IDE_HFLAG_ERROR_STOPS_FIFO) == 0) { int nsect = drive->mult_count ? drive->mult_count : 1; ide_pad_transfer(drive, READ, nsect * SECTOR_SIZE); } if (rq->errors >= ERROR_MAX || blk_noretry_request(rq)) { ide_kill_rq(drive, rq); return ide_stopped; } if (hwif->tp_ops->read_status(hwif) & (ATA_BUSY | ATA_DRQ)) rq->errors |= ERROR_RESET; if ((rq->errors & ERROR_RESET) == ERROR_RESET) { ++rq->errors; return ide_do_reset(drive); } if ((rq->errors & ERROR_RECAL) == ERROR_RECAL) drive->special.b.recalibrate = 1; ++rq->errors; return ide_stopped; } static ide_startstop_t ide_atapi_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err) { ide_hwif_t *hwif = drive->hwif; if ((stat & ATA_BUSY) || ((stat & ATA_DF) && (drive->dev_flags & IDE_DFLAG_NOWERR) == 0)) { /* other bits are useless when BUSY */ rq->errors |= ERROR_RESET; } else { /* add decoding error stuff */ } if (hwif->tp_ops->read_status(hwif) & (ATA_BUSY | ATA_DRQ)) /* force an abort */ hwif->tp_ops->exec_command(hwif, ATA_CMD_IDLEIMMEDIATE); if (rq->errors >= ERROR_MAX) { ide_kill_rq(drive, rq); } else { if ((rq->errors & ERROR_RESET) == ERROR_RESET) { ++rq->errors; return ide_do_reset(drive); } ++rq->errors; } return ide_stopped; } ide_startstop_t __ide_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err) { if (drive->media == ide_disk) return ide_ata_error(drive, rq, stat, err); return ide_atapi_error(drive, rq, stat, err); } EXPORT_SYMBOL_GPL(__ide_error); /** * ide_error - handle an error on the IDE * @drive: drive the error occurred on * @msg: message to report * @stat: status bits * * ide_error() takes action based on the error returned by the drive. * For normal I/O that may well include retries. We deal with * both new-style (taskfile) and old style command handling here. * In the case of taskfile command handling there is work left to * do */ ide_startstop_t ide_error (ide_drive_t *drive, const char *msg, u8 stat) { struct request *rq; u8 err; err = ide_dump_status(drive, msg, stat); if ((rq = HWGROUP(drive)->rq) == NULL) return ide_stopped; /* retry only "normal" I/O: */ if (!blk_fs_request(rq)) { rq->errors = 1; ide_end_drive_cmd(drive, stat, err); return ide_stopped; } if (rq->rq_disk) { ide_driver_t *drv; drv = *(ide_driver_t **)rq->rq_disk->private_data; return drv->error(drive, rq, stat, err); } else return __ide_error(drive, rq, stat, err); } EXPORT_SYMBOL_GPL(ide_error); static void ide_tf_set_specify_cmd(ide_drive_t *drive, struct ide_taskfile *tf) { tf->nsect = drive->sect; tf->lbal = drive->sect; tf->lbam = drive->cyl; tf->lbah = drive->cyl >> 8; tf->device = (drive->head - 1) | drive->select; tf->command = ATA_CMD_INIT_DEV_PARAMS; } static void ide_tf_set_restore_cmd(ide_drive_t *drive, struct ide_taskfile *tf) { tf->nsect = drive->sect; tf->command = ATA_CMD_RESTORE; } static void ide_tf_set_setmult_cmd(ide_drive_t *drive, struct ide_taskfile *tf) { tf->nsect = drive->mult_req; tf->command = ATA_CMD_SET_MULTI; } static ide_startstop_t ide_disk_special(ide_drive_t *drive) { special_t *s = &drive->special; ide_task_t args; memset(&args, 0, sizeof(ide_task_t)); args.data_phase = TASKFILE_NO_DATA; if (s->b.set_geometry) { s->b.set_geometry = 0; ide_tf_set_specify_cmd(drive, &args.tf); } else if (s->b.recalibrate) { s->b.recalibrate = 0; ide_tf_set_restore_cmd(drive, &args.tf); } else if (s->b.set_multmode) { s->b.set_multmode = 0; ide_tf_set_setmult_cmd(drive, &args.tf); } else if (s->all) { int special = s->all; s->all = 0; printk(KERN_ERR "%s: bad special flag: 0x%02x\n", drive->name, special); return ide_stopped; } args.tf_flags = IDE_TFLAG_TF | IDE_TFLAG_DEVICE | IDE_TFLAG_CUSTOM_HANDLER; do_rw_taskfile(drive, &args); return ide_started; } /** * do_special - issue some special commands * @drive: drive the command is for * * do_special() is used to issue ATA_CMD_INIT_DEV_PARAMS, * ATA_CMD_RESTORE and ATA_CMD_SET_MULTI commands to a drive. * * It used to do much more, but has been scaled back. */ static ide_startstop_t do_special (ide_drive_t *drive) { special_t *s = &drive->special; #ifdef DEBUG printk("%s: do_special: 0x%02x\n", drive->name, s->all); #endif if (drive->media == ide_disk) return ide_disk_special(drive); s->all = 0; drive->mult_req = 0; return ide_stopped; } void ide_map_sg(ide_drive_t *drive, struct request *rq) { ide_hwif_t *hwif = drive->hwif; struct scatterlist *sg = hwif->sg_table; if (hwif->sg_mapped) /* needed by ide-scsi */ return; if (rq->cmd_type != REQ_TYPE_ATA_TASKFILE) { hwif->sg_nents = blk_rq_map_sg(drive->queue, rq, sg); } else { sg_init_one(sg, rq->buffer, rq->nr_sectors * SECTOR_SIZE); hwif->sg_nents = 1; } } EXPORT_SYMBOL_GPL(ide_map_sg); void ide_init_sg_cmd(ide_drive_t *drive, struct request *rq) { ide_hwif_t *hwif = drive->hwif; hwif->nsect = hwif->nleft = rq->nr_sectors; hwif->cursg_ofs = 0; hwif->cursg = NULL; } EXPORT_SYMBOL_GPL(ide_init_sg_cmd); /** * execute_drive_command - issue special drive command * @drive: the drive to issue the command on * @rq: the request structure holding the command * * execute_drive_cmd() issues a special drive command, usually * initiated by ioctl() from the external hdparm program. The * command can be a drive command, drive task or taskfile * operation. Weirdly you can call it with NULL to wait for * all commands to finish. Don't do this as that is due to change */ static ide_startstop_t execute_drive_cmd (ide_drive_t *drive, struct request *rq) { ide_hwif_t *hwif = HWIF(drive); ide_task_t *task = rq->special; if (task) { hwif->data_phase = task->data_phase; switch (hwif->data_phase) { case TASKFILE_MULTI_OUT: case TASKFILE_OUT: case TASKFILE_MULTI_IN: case TASKFILE_IN: ide_init_sg_cmd(drive, rq); ide_map_sg(drive, rq); default: break; } return do_rw_taskfile(drive, task); } /* * NULL is actually a valid way of waiting for * all current requests to be flushed from the queue. */ #ifdef DEBUG printk("%s: DRIVE_CMD (null)\n", drive->name); #endif ide_end_drive_cmd(drive, hwif->tp_ops->read_status(hwif), ide_read_error(drive)); return ide_stopped; } int ide_devset_execute(ide_drive_t *drive, const struct ide_devset *setting, int arg) { struct request_queue *q = drive->queue; struct request *rq; int ret = 0; if (!(setting->flags & DS_SYNC)) return setting->set(drive, arg); rq = blk_get_request(q, READ, __GFP_WAIT); rq->cmd_type = REQ_TYPE_SPECIAL; rq->cmd_len = 5; rq->cmd[0] = REQ_DEVSET_EXEC; *(int *)&rq->cmd[1] = arg; rq->special = setting->set; if (blk_execute_rq(q, NULL, rq, 0)) ret = rq->errors; blk_put_request(rq); return ret; } EXPORT_SYMBOL_GPL(ide_devset_execute); static ide_startstop_t ide_special_rq(ide_drive_t *drive, struct request *rq) { u8 cmd = rq->cmd[0]; if (cmd == REQ_PARK_HEADS || cmd == REQ_UNPARK_HEADS) { ide_task_t task; struct ide_taskfile *tf = &task.tf; memset(&task, 0, sizeof(task)); if (cmd == REQ_PARK_HEADS) { drive->sleep = *(unsigned long *)rq->special; drive->dev_flags |= IDE_DFLAG_SLEEPING; tf->command = ATA_CMD_IDLEIMMEDIATE; tf->feature = 0x44; tf->lbal = 0x4c; tf->lbam = 0x4e; tf->lbah = 0x55; task.tf_flags |= IDE_TFLAG_CUSTOM_HANDLER; } else /* cmd == REQ_UNPARK_HEADS */ tf->command = ATA_CMD_CHK_POWER; task.tf_flags |= IDE_TFLAG_TF | IDE_TFLAG_DEVICE; task.rq = rq; drive->hwif->data_phase = task.data_phase = TASKFILE_NO_DATA; return do_rw_taskfile(drive, &task); } switch (cmd) { case REQ_DEVSET_EXEC: { int err, (*setfunc)(ide_drive_t *, int) = rq->special; err = setfunc(drive, *(int *)&rq->cmd[1]); if (err) rq->errors = err; else err = 1; ide_end_request(drive, err, 0); return ide_stopped; } case REQ_DRIVE_RESET: return ide_do_reset(drive); default: blk_dump_rq_flags(rq, "ide_special_rq - bad request"); ide_end_request(drive, 0, 0); return ide_stopped; } } /** * start_request - start of I/O and command issuing for IDE * * start_request() initiates handling of a new I/O request. It * accepts commands and I/O (read/write) requests. * * FIXME: this function needs a rename */ static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq) { ide_startstop_t startstop; BUG_ON(!blk_rq_started(rq)); #ifdef DEBUG printk("%s: start_request: current=0x%08lx\n", HWIF(drive)->name, (unsigned long) rq); #endif /* bail early if we've exceeded max_failures */ if (drive->max_failures && (drive->failures > drive->max_failures)) { rq->cmd_flags |= REQ_FAILED; goto kill_rq; } if (blk_pm_request(rq)) ide_check_pm_state(drive, rq); SELECT_DRIVE(drive); if (ide_wait_stat(&startstop, drive, drive->ready_stat, ATA_BUSY | ATA_DRQ, WAIT_READY)) { printk(KERN_ERR "%s: drive not ready for command\n", drive->name); return startstop; } if (!drive->special.all) { ide_driver_t *drv; /* * We reset the drive so we need to issue a SETFEATURES. * Do it _after_ do_special() restored device parameters. */ if (drive->current_speed == 0xff) ide_config_drive_speed(drive, drive->desired_speed); if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) return execute_drive_cmd(drive, rq); else if (blk_pm_request(rq)) { struct request_pm_state *pm = rq->data; #ifdef DEBUG_PM printk("%s: start_power_step(step: %d)\n", drive->name, pm->pm_step); #endif startstop = ide_start_power_step(drive, rq); if (startstop == ide_stopped && pm->pm_step == IDE_PM_COMPLETED) ide_complete_pm_request(drive, rq); return startstop; } else if (!rq->rq_disk && blk_special_request(rq)) /* * TODO: Once all ULDs have been modified to * check for specific op codes rather than * blindly accepting any special request, the * check for ->rq_disk above may be replaced * by a more suitable mechanism or even * dropped entirely. */ return ide_special_rq(drive, rq); drv = *(ide_driver_t **)rq->rq_disk->private_data; return drv->do_request(drive, rq, rq->sector); } return do_special(drive); kill_rq: ide_kill_rq(drive, rq); return ide_stopped; } /** * ide_stall_queue - pause an IDE device * @drive: drive to stall * @timeout: time to stall for (jiffies) * * ide_stall_queue() can be used by a drive to give excess bandwidth back * to the hwgroup by sleeping for timeout jiffies. */ void ide_stall_queue (ide_drive_t *drive, unsigned long timeout) { if (timeout > WAIT_WORSTCASE) timeout = WAIT_WORSTCASE; drive->sleep = timeout + jiffies; drive->dev_flags |= IDE_DFLAG_SLEEPING; } EXPORT_SYMBOL(ide_stall_queue); #define WAKEUP(drive) ((drive)->service_start + 2 * (drive)->service_time) /** * choose_drive - select a drive to service * @hwgroup: hardware group to select on * * choose_drive() selects the next drive which will be serviced. * This is necessary because the IDE layer can't issue commands * to both drives on the same cable, unlike SCSI. */ static inline ide_drive_t *choose_drive (ide_hwgroup_t *hwgroup) { ide_drive_t *drive, *best; repeat: best = NULL; drive = hwgroup->drive; /* * drive is doing pre-flush, ordered write, post-flush sequence. even * though that is 3 requests, it must be seen as a single transaction. * we must not preempt this drive until that is complete */ if (blk_queue_flushing(drive->queue)) { /* * small race where queue could get replugged during * the 3-request flush cycle, just yank the plug since * we want it to finish asap */ blk_remove_plug(drive->queue); return drive; } do { u8 dev_s = !!(drive->dev_flags & IDE_DFLAG_SLEEPING); u8 best_s = (best && !!(best->dev_flags & IDE_DFLAG_SLEEPING)); if ((dev_s == 0 || time_after_eq(jiffies, drive->sleep)) && !elv_queue_empty(drive->queue)) { if (best == NULL || (dev_s && (best_s == 0 || time_before(drive->sleep, best->sleep))) || (best_s == 0 && time_before(WAKEUP(drive), WAKEUP(best)))) { if (!blk_queue_plugged(drive->queue)) best = drive; } } } while ((drive = drive->next) != hwgroup->drive); if (best && (best->dev_flags & IDE_DFLAG_NICE1) && (best->dev_flags & IDE_DFLAG_SLEEPING) == 0 && best != hwgroup->drive && best->service_time > WAIT_MIN_SLEEP) { long t = (signed long)(WAKEUP(best) - jiffies); if (t >= WAIT_MIN_SLEEP) { /* * We *may* have some time to spare, but first let's see if * someone can potentially benefit from our nice mood today.. */ drive = best->next; do { if ((drive->dev_flags & IDE_DFLAG_SLEEPING) == 0 && time_before(jiffies - best->service_time, WAKEUP(drive)) && time_before(WAKEUP(drive), jiffies + t)) { ide_stall_queue(best, min_t(long, t, 10 * WAIT_MIN_SLEEP)); goto repeat; } } while ((drive = drive->next) != best); } } return best; } /* * Issue a new request to a drive from hwgroup * Caller must have already done spin_lock_irqsave(&hwgroup->lock, ..); * * A hwgroup is a serialized group of IDE interfaces. Usually there is * exactly one hwif (interface) per hwgroup, but buggy controllers (eg. CMD640) * may have both interfaces in a single hwgroup to "serialize" access. * Or possibly multiple ISA interfaces can share a common IRQ by being grouped * together into one hwgroup for serialized access. * * Note also that several hwgroups can end up sharing a single IRQ, * possibly along with many other devices. This is especially common in * PCI-based systems with off-board IDE controller cards. * * The IDE driver uses a per-hwgroup spinlock to protect * access to the request queues, and to protect the hwgroup->busy flag. * * The first thread into the driver for a particular hwgroup sets the * hwgroup->busy flag to indicate that this hwgroup is now active, * and then initiates processing of the top request from the request queue. * * Other threads attempting entry notice the busy setting, and will simply * queue their new requests and exit immediately. Note that hwgroup->busy * remains set even when the driver is merely awaiting the next interrupt. * Thus, the meaning is "this hwgroup is busy processing a request". * * When processing of a request completes, the completing thread or IRQ-handler * will start the next request from the queue. If no more work remains, * the driver will clear the hwgroup->busy flag and exit. * * The per-hwgroup spinlock is used to protect all access to the * hwgroup->busy flag, but is otherwise not needed for most processing in * the driver. This makes the driver much more friendlier to shared IRQs * than previous designs, while remaining 100% (?) SMP safe and capable. */ void do_ide_request(struct request_queue *q) { ide_drive_t *orig_drive = q->queuedata; ide_hwgroup_t *hwgroup = orig_drive->hwif->hwgroup; ide_drive_t *drive; ide_hwif_t *hwif; struct request *rq; ide_startstop_t startstop; /* caller must own hwgroup->lock */ BUG_ON(!irqs_disabled()); while (!hwgroup->busy) { hwgroup->busy = 1; /* for atari only */ ide_get_lock(ide_intr, hwgroup); drive = choose_drive(hwgroup); if (drive == NULL) { int sleeping = 0; unsigned long sleep = 0; /* shut up, gcc */ hwgroup->rq = NULL; drive = hwgroup->drive; do { if ((drive->dev_flags & IDE_DFLAG_SLEEPING) && (sleeping == 0 || time_before(drive->sleep, sleep))) { sleeping = 1; sleep = drive->sleep; } } while ((drive = drive->next) != hwgroup->drive); if (sleeping) { /* * Take a short snooze, and then wake up this hwgroup again. * This gives other hwgroups on the same a chance to * play fairly with us, just in case there are big differences * in relative throughputs.. don't want to hog the cpu too much. */ if (time_before(sleep, jiffies + WAIT_MIN_SLEEP)) sleep = jiffies + WAIT_MIN_SLEEP; #if 1 if (timer_pending(&hwgroup->timer)) printk(KERN_CRIT "ide_set_handler: timer already active\n"); #endif /* so that ide_timer_expiry knows what to do */ hwgroup->sleeping = 1; hwgroup->req_gen_timer = hwgroup->req_gen; mod_timer(&hwgroup->timer, sleep); /* we purposely leave hwgroup->busy==1 * while sleeping */ } else { /* Ugly, but how can we sleep for the lock * otherwise? perhaps from tq_disk? */ /* for atari only */ ide_release_lock(); hwgroup->busy = 0; } /* no more work for this hwgroup (for now) */ goto plug_device; } if (drive != orig_drive) goto plug_device; hwif = drive->hwif; if (hwif != hwgroup->hwif) { /* * set nIEN for previous hwif, drives in the * quirk_list may not like intr setups/cleanups */ if (drive->quirk_list == 0) hwif->tp_ops->set_irq(hwif, 0); } hwgroup->hwif = hwif; hwgroup->drive = drive; drive->dev_flags &= ~(IDE_DFLAG_SLEEPING | IDE_DFLAG_PARKED); drive->service_start = jiffies; /* * we know that the queue isn't empty, but this can happen * if the q->prep_rq_fn() decides to kill a request */ rq = elv_next_request(drive->queue); if (!rq) { hwgroup->busy = 0; break; } /* * Sanity: don't accept a request that isn't a PM request * if we are currently power managed. This is very important as * blk_stop_queue() doesn't prevent the elv_next_request() * above to return us whatever is in the queue. Since we call * ide_do_request() ourselves, we end up taking requests while * the queue is blocked... * * We let requests forced at head of queue with ide-preempt * though. I hope that doesn't happen too much, hopefully not * unless the subdriver triggers such a thing in its own PM * state machine. */ if ((drive->dev_flags & IDE_DFLAG_BLOCKED) && blk_pm_request(rq) == 0 && (rq->cmd_flags & REQ_PREEMPT) == 0) { /* We clear busy, there should be no pending ATA command at this point. */ hwgroup->busy = 0; goto plug_device; } hwgroup->rq = rq; spin_unlock_irq(&hwgroup->lock); startstop = start_request(drive, rq); spin_lock_irq(&hwgroup->lock); if (startstop == ide_stopped) { hwgroup->busy = 0; if (!elv_queue_empty(orig_drive->queue)) blk_plug_device(orig_drive->queue); } } return; plug_device: if (!elv_queue_empty(orig_drive->queue)) blk_plug_device(orig_drive->queue); } /* * un-busy the hwgroup etc, and clear any pending DMA status. we want to * retry the current request in pio mode instead of risking tossing it * all away */ static ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error) { ide_hwif_t *hwif = HWIF(drive); struct request *rq; ide_startstop_t ret = ide_stopped; /* * end current dma transaction */ if (error < 0) { printk(KERN_WARNING "%s: DMA timeout error\n", drive->name); (void)hwif->dma_ops->dma_end(drive); ret = ide_error(drive, "dma timeout error", hwif->tp_ops->read_status(hwif)); } else { printk(KERN_WARNING "%s: DMA timeout retry\n", drive->name); hwif->dma_ops->dma_timeout(drive); } /* * disable dma for now, but remember that we did so because of * a timeout -- we'll reenable after we finish this next request * (or rather the first chunk of it) in pio. */ drive->dev_flags |= IDE_DFLAG_DMA_PIO_RETRY; drive->retry_pio++; ide_dma_off_quietly(drive); /* * un-busy drive etc (hwgroup->busy is cleared on return) and * make sure request is sane */ rq = HWGROUP(drive)->rq; if (!rq) goto out; HWGROUP(drive)->rq = NULL; rq->errors = 0; if (!rq->bio) goto out; rq->sector = rq->bio->bi_sector; rq->current_nr_sectors = bio_iovec(rq->bio)->bv_len >> 9; rq->hard_cur_sectors = rq->current_nr_sectors; rq->buffer = bio_data(rq->bio); out: return ret; } /** * ide_timer_expiry - handle lack of an IDE interrupt * @data: timer callback magic (hwgroup) * * An IDE command has timed out before the expected drive return * occurred. At this point we attempt to clean up the current * mess. If the current handler includes an expiry handler then * we invoke the expiry handler, and providing it is happy the * work is done. If that fails we apply generic recovery rules * invoking the handler and checking the drive DMA status. We * have an excessively incestuous relationship with the DMA * logic that wants cleaning up. */ void ide_timer_expiry (unsigned long data) { ide_hwgroup_t *hwgroup = (ide_hwgroup_t *) data; ide_handler_t *handler; ide_expiry_t *expiry; unsigned long flags; unsigned long wait = -1; spin_lock_irqsave(&hwgroup->lock, flags); if (((handler = hwgroup->handler) == NULL) || (hwgroup->req_gen != hwgroup->req_gen_timer)) { /* * Either a marginal timeout occurred * (got the interrupt just as timer expired), * or we were "sleeping" to give other devices a chance. * Either way, we don't really want to complain about anything. */ if (hwgroup->sleeping) { hwgroup->sleeping = 0; hwgroup->busy = 0; } } else { ide_drive_t *drive = hwgroup->drive; if (!drive) { printk(KERN_ERR "ide_timer_expiry: hwgroup->drive was NULL\n"); hwgroup->handler = NULL; } else { ide_hwif_t *hwif; ide_startstop_t startstop = ide_stopped; if (!hwgroup->busy) { hwgroup->busy = 1; /* paranoia */ printk(KERN_ERR "%s: ide_timer_expiry: hwgroup->busy was 0 ??\n", drive->name); } if ((expiry = hwgroup->expiry) != NULL) { /* continue */ if ((wait = expiry(drive)) > 0) { /* reset timer */ hwgroup->timer.expires = jiffies + wait; hwgroup->req_gen_timer = hwgroup->req_gen; add_timer(&hwgroup->timer); spin_unlock_irqrestore(&hwgroup->lock, flags); return; } } hwgroup->handler = NULL; /* * We need to simulate a real interrupt when invoking * the handler() function, which means we need to * globally mask the specific IRQ: */ spin_unlock(&hwgroup->lock); hwif = HWIF(drive); /* disable_irq_nosync ?? */ disable_irq(hwif->irq); /* local CPU only, * as if we were handling an interrupt */ local_irq_disable(); if (hwgroup->polling) { startstop = handler(drive); } else if (drive_is_ready(drive)) { if (drive->waiting_for_dma) hwif->dma_ops->dma_lost_irq(drive); (void)ide_ack_intr(hwif); printk(KERN_WARNING "%s: lost interrupt\n", drive->name); startstop = handler(drive); } else { if (drive->waiting_for_dma) { startstop = ide_dma_timeout_retry(drive, wait); } else startstop = ide_error(drive, "irq timeout", hwif->tp_ops->read_status(hwif)); } drive->service_time = jiffies - drive->service_start; spin_lock_irq(&hwgroup->lock); enable_irq(hwif->irq); if (startstop == ide_stopped) { hwgroup->busy = 0; if (!elv_queue_empty(drive->queue)) blk_plug_device(drive->queue); } } } spin_unlock_irqrestore(&hwgroup->lock, flags); } /** * unexpected_intr - handle an unexpected IDE interrupt * @irq: interrupt line * @hwgroup: hwgroup being processed * * There's nothing really useful we can do with an unexpected interrupt, * other than reading the status register (to clear it), and logging it. * There should be no way that an irq can happen before we're ready for it, * so we needn't worry much about losing an "important" interrupt here. * * On laptops (and "green" PCs), an unexpected interrupt occurs whenever * the drive enters "idle", "standby", or "sleep" mode, so if the status * looks "good", we just ignore the interrupt completely. * * This routine assumes __cli() is in effect when called. * * If an unexpected interrupt happens on irq15 while we are handling irq14 * and if the two interfaces are "serialized" (CMD640), then it looks like * we could screw up by interfering with a new request being set up for * irq15. * * In reality, this is a non-issue. The new command is not sent unless * the drive is ready to accept one, in which case we know the drive is * not trying to interrupt us. And ide_set_handler() is always invoked * before completing the issuance of any new drive command, so we will not * be accidentally invoked as a result of any valid command completion * interrupt. * * Note that we must walk the entire hwgroup here. We know which hwif * is doing the current command, but we don't know which hwif burped * mysteriously. */ static void unexpected_intr (int irq, ide_hwgroup_t *hwgroup) { u8 stat; ide_hwif_t *hwif = hwgroup->hwif; /* * handle the unexpected interrupt */ do { if (hwif->irq == irq) { stat = hwif->tp_ops->read_status(hwif); if (!OK_STAT(stat, ATA_DRDY, BAD_STAT)) { /* Try to not flood the console with msgs */ static unsigned long last_msgtime, count; ++count; if (time_after(jiffies, last_msgtime + HZ)) { last_msgtime = jiffies; printk(KERN_ERR "%s%s: unexpected interrupt, " "status=0x%02x, count=%ld\n", hwif->name, (hwif->next==hwgroup->hwif) ? "" : "(?)", stat, count); } } } } while ((hwif = hwif->next) != hwgroup->hwif); } /** * ide_intr - default IDE interrupt handler * @irq: interrupt number * @dev_id: hwif group * @regs: unused weirdness from the kernel irq layer * * This is the default IRQ handler for the IDE layer. You should * not need to override it. If you do be aware it is subtle in * places * * hwgroup->hwif is the interface in the group currently performing * a command. hwgroup->drive is the drive and hwgroup->handler is * the IRQ handler to call. As we issue a command the handlers * step through multiple states, reassigning the handler to the * next step in the process. Unlike a smart SCSI controller IDE * expects the main processor to sequence the various transfer * stages. We also manage a poll timer to catch up with most * timeout situations. There are still a few where the handlers * don't ever decide to give up. * * The handler eventually returns ide_stopped to indicate the * request completed. At this point we issue the next request * on the hwgroup and the process begins again. */ irqreturn_t ide_intr (int irq, void *dev_id) { unsigned long flags; ide_hwgroup_t *hwgroup = (ide_hwgroup_t *)dev_id; ide_hwif_t *hwif = hwgroup->hwif; ide_drive_t *drive; ide_handler_t *handler; ide_startstop_t startstop; irqreturn_t irq_ret = IRQ_NONE; spin_lock_irqsave(&hwgroup->lock, flags); if (!ide_ack_intr(hwif)) goto out; if ((handler = hwgroup->handler) == NULL || hwgroup->polling) { /* * Not expecting an interrupt from this drive. * That means this could be: * (1) an interrupt from another PCI device * sharing the same PCI INT# as us. * or (2) a drive just entered sleep or standby mode, * and is interrupting to let us know. * or (3) a spurious interrupt of unknown origin. * * For PCI, we cannot tell the difference, * so in that case we just ignore it and hope it goes away. * * FIXME: unexpected_intr should be hwif-> then we can * remove all the ifdef PCI crap */ #ifdef CONFIG_BLK_DEV_IDEPCI if (hwif->chipset != ide_pci) #endif /* CONFIG_BLK_DEV_IDEPCI */ { /* * Probably not a shared PCI interrupt, * so we can safely try to do something about it: */ unexpected_intr(irq, hwgroup); #ifdef CONFIG_BLK_DEV_IDEPCI } else { /* * Whack the status register, just in case * we have a leftover pending IRQ. */ (void)hwif->tp_ops->read_status(hwif); #endif /* CONFIG_BLK_DEV_IDEPCI */ } goto out; } drive = hwgroup->drive; if (!drive) { /* * This should NEVER happen, and there isn't much * we could do about it here. * * [Note - this can occur if the drive is hot unplugged] */ goto out_handled; } if (!drive_is_ready(drive)) /* * This happens regularly when we share a PCI IRQ with * another device. Unfortunately, it can also happen * with some buggy drives that trigger the IRQ before * their status register is up to date. Hopefully we have * enough advance overhead that the latter isn't a problem. */ goto out; if (!hwgroup->busy) { hwgroup->busy = 1; /* paranoia */ printk(KERN_ERR "%s: ide_intr: hwgroup->busy was 0 ??\n", drive->name); } hwgroup->handler = NULL; hwgroup->req_gen++; del_timer(&hwgroup->timer); spin_unlock(&hwgroup->lock); if (hwif->port_ops && hwif->port_ops->clear_irq) hwif->port_ops->clear_irq(drive); if (drive->dev_flags & IDE_DFLAG_UNMASK) local_irq_enable_in_hardirq(); /* service this interrupt, may set handler for next interrupt */ startstop = handler(drive); spin_lock_irq(&hwgroup->lock); /* * Note that handler() may have set things up for another * interrupt to occur soon, but it cannot happen until * we exit from this routine, because it will be the * same irq as is currently being serviced here, and Linux * won't allow another of the same (on any CPU) until we return. */ drive->service_time = jiffies - drive->service_start; if (startstop == ide_stopped) { if (hwgroup->handler == NULL) { /* paranoia */ hwgroup->busy = 0; if (!elv_queue_empty(drive->queue)) blk_plug_device(drive->queue); } else printk(KERN_ERR "%s: %s: huh? expected NULL handler " "on exit\n", __func__, drive->name); } out_handled: irq_ret = IRQ_HANDLED; out: spin_unlock_irqrestore(&hwgroup->lock, flags); return irq_ret; } /** * ide_do_drive_cmd - issue IDE special command * @drive: device to issue command * @rq: request to issue * * This function issues a special IDE device request * onto the request queue. * * the rq is queued at the head of the request queue, displacing * the currently-being-processed request and this function * returns immediately without waiting for the new rq to be * completed. This is VERY DANGEROUS, and is intended for * careful use by the ATAPI tape/cdrom driver code. */ void ide_do_drive_cmd(ide_drive_t *drive, struct request *rq) { ide_hwgroup_t *hwgroup = drive->hwif->hwgroup; struct request_queue *q = drive->queue; unsigned long flags; hwgroup->rq = NULL; spin_lock_irqsave(q->queue_lock, flags); __elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 0); blk_start_queueing(q); spin_unlock_irqrestore(q->queue_lock, flags); } EXPORT_SYMBOL(ide_do_drive_cmd); void ide_pktcmd_tf_load(ide_drive_t *drive, u32 tf_flags, u16 bcount, u8 dma) { ide_hwif_t *hwif = drive->hwif; ide_task_t task; memset(&task, 0, sizeof(task)); task.tf_flags = IDE_TFLAG_OUT_LBAH | IDE_TFLAG_OUT_LBAM | IDE_TFLAG_OUT_FEATURE | tf_flags; task.tf.feature = dma; /* Use PIO/DMA */ task.tf.lbam = bcount & 0xff; task.tf.lbah = (bcount >> 8) & 0xff; ide_tf_dump(drive->name, &task.tf); hwif->tp_ops->set_irq(hwif, 1); SELECT_MASK(drive, 0); hwif->tp_ops->tf_load(drive, &task); } EXPORT_SYMBOL_GPL(ide_pktcmd_tf_load); void ide_pad_transfer(ide_drive_t *drive, int write, int len) { ide_hwif_t *hwif = drive->hwif; u8 buf[4] = { 0 }; while (len > 0) { if (write) hwif->tp_ops->output_data(drive, NULL, buf, min(4, len)); else hwif->tp_ops->input_data(drive, NULL, buf, min(4, len)); len -= 4; } } EXPORT_SYMBOL_GPL(ide_pad_transfer);