| /* |
| * 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 <linux/module.h> |
| #include <linux/types.h> |
| #include <linux/string.h> |
| #include <linux/kernel.h> |
| #include <linux/timer.h> |
| #include <linux/mm.h> |
| #include <linux/interrupt.h> |
| #include <linux/major.h> |
| #include <linux/errno.h> |
| #include <linux/genhd.h> |
| #include <linux/blkpg.h> |
| #include <linux/slab.h> |
| #include <linux/init.h> |
| #include <linux/pci.h> |
| #include <linux/delay.h> |
| #include <linux/ide.h> |
| #include <linux/hdreg.h> |
| #include <linux/completion.h> |
| #include <linux/reboot.h> |
| #include <linux/cdrom.h> |
| #include <linux/seq_file.h> |
| #include <linux/device.h> |
| #include <linux/kmod.h> |
| #include <linux/scatterlist.h> |
| #include <linux/bitops.h> |
| |
| #include <asm/byteorder.h> |
| #include <asm/irq.h> |
| #include <asm/uaccess.h> |
| #include <asm/io.h> |
| |
| 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 (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); |
| |
| /* |
| * Issue a new request to a drive from hwgroup |
| * |
| * 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 lock 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 *drive = q->queuedata; |
| ide_hwif_t *hwif = drive->hwif; |
| ide_hwgroup_t *hwgroup = hwif->hwgroup; |
| struct request *rq; |
| ide_startstop_t startstop; |
| |
| /* |
| * 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(q)) |
| /* |
| * 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(q); |
| |
| spin_unlock_irq(q->queue_lock); |
| spin_lock_irq(&hwgroup->lock); |
| |
| if (!ide_lock_hwgroup(hwgroup)) { |
| ide_hwif_t *prev_port; |
| repeat: |
| prev_port = hwgroup->hwif; |
| hwgroup->rq = NULL; |
| |
| if (drive->dev_flags & IDE_DFLAG_SLEEPING) { |
| if (time_before(drive->sleep, jiffies)) { |
| ide_unlock_hwgroup(hwgroup); |
| goto plug_device; |
| } |
| } |
| |
| if (hwif != prev_port) { |
| /* |
| * set nIEN for previous port, drives in the |
| * quirk_list may not like intr setups/cleanups |
| */ |
| if (hwgroup->drive->quirk_list == 0) |
| prev_port->tp_ops->set_irq(prev_port, 0); |
| } |
| hwgroup->hwif = hwif; |
| hwgroup->drive = drive; |
| drive->dev_flags &= ~(IDE_DFLAG_SLEEPING | IDE_DFLAG_PARKED); |
| |
| spin_unlock_irq(&hwgroup->lock); |
| spin_lock_irq(q->queue_lock); |
| /* |
| * 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); |
| spin_unlock_irq(q->queue_lock); |
| spin_lock_irq(&hwgroup->lock); |
| |
| if (!rq) { |
| ide_unlock_hwgroup(hwgroup); |
| goto out; |
| } |
| |
| /* |
| * 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) { |
| /* there should be no pending command at this point */ |
| ide_unlock_hwgroup(hwgroup); |
| 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) |
| goto repeat; |
| } else |
| goto plug_device; |
| out: |
| spin_unlock_irq(&hwgroup->lock); |
| spin_lock_irq(q->queue_lock); |
| return; |
| |
| plug_device: |
| spin_unlock_irq(&hwgroup->lock); |
| spin_lock_irq(q->queue_lock); |
| |
| if (!elv_queue_empty(q)) |
| blk_plug_device(q); |
| } |
| |
| /* |
| * 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; |
| } |
| |
| static void ide_plug_device(ide_drive_t *drive) |
| { |
| struct request_queue *q = drive->queue; |
| unsigned long flags; |
| |
| spin_lock_irqsave(q->queue_lock, flags); |
| if (!elv_queue_empty(q)) |
| blk_plug_device(q); |
| spin_unlock_irqrestore(q->queue_lock, flags); |
| } |
| |
| /** |
| * 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_drive_t *uninitialized_var(drive); |
| ide_handler_t *handler; |
| ide_expiry_t *expiry; |
| unsigned long flags; |
| unsigned long wait = -1; |
| int plug_device = 0; |
| |
| 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. |
| */ |
| } else { |
| 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 ((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)); |
| } |
| spin_lock_irq(&hwgroup->lock); |
| enable_irq(hwif->irq); |
| if (startstop == ide_stopped) { |
| ide_unlock_hwgroup(hwgroup); |
| plug_device = 1; |
| } |
| } |
| } |
| spin_unlock_irqrestore(&hwgroup->lock, flags); |
| |
| if (plug_device) |
| ide_plug_device(drive); |
| } |
| |
| /** |
| * 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 *uninitialized_var(drive); |
| ide_handler_t *handler; |
| ide_startstop_t startstop; |
| irqreturn_t irq_ret = IRQ_NONE; |
| int plug_device = 0; |
| |
| 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; |
| |
| 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. |
| */ |
| if (startstop == ide_stopped) { |
| if (hwgroup->handler == NULL) { /* paranoia */ |
| ide_unlock_hwgroup(hwgroup); |
| plug_device = 1; |
| } 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); |
| |
| if (plug_device) |
| ide_plug_device(drive); |
| |
| 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); |
| 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); |