diff options
Diffstat (limited to 'drivers/ide/ide-io.c')
| -rw-r--r-- | drivers/ide/ide-io.c | 1681 |
1 files changed, 1681 insertions, 0 deletions
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c new file mode 100644 index 00000000000..248e3cc8b35 --- /dev/null +++ b/drivers/ide/ide-io.c @@ -0,0 +1,1681 @@ +/* + * 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/config.h> +#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/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 <asm/byteorder.h> +#include <asm/irq.h> +#include <asm/uaccess.h> +#include <asm/io.h> +#include <asm/bitops.h> + +int __ide_end_request(ide_drive_t *drive, struct request *rq, int uptodate, + int nr_sectors) +{ + int ret = 1; + + BUG_ON(!(rq->flags & REQ_STARTED)); + + /* + * if failfast is set on a request, override number of sectors and + * complete the whole request right now + */ + if (blk_noretry_request(rq) && end_io_error(uptodate)) + nr_sectors = rq->hard_nr_sectors; + + if (!blk_fs_request(rq) && end_io_error(uptodate) && !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->state == DMA_PIO_RETRY && drive->retry_pio <= 3) { + drive->state = 0; + HWGROUP(drive)->hwif->ide_dma_on(drive); + } + + if (!end_that_request_first(rq, uptodate, nr_sectors)) { + add_disk_randomness(rq->rq_disk); + + if (blk_rq_tagged(rq)) + blk_queue_end_tag(drive->queue, rq); + + blkdev_dequeue_request(rq); + HWGROUP(drive)->rq = NULL; + end_that_request_last(rq); + ret = 0; + } + return ret; +} +EXPORT_SYMBOL(__ide_end_request); + +/** + * 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) +{ + struct request *rq; + unsigned long flags; + int ret = 1; + + spin_lock_irqsave(&ide_lock, flags); + rq = HWGROUP(drive)->rq; + + if (!nr_sectors) + nr_sectors = rq->hard_cur_sectors; + + if (blk_complete_barrier_rq_locked(drive->queue, rq, nr_sectors)) + ret = rq->nr_sectors != 0; + else + ret = __ide_end_request(drive, rq, uptodate, nr_sectors); + + spin_unlock_irqrestore(&ide_lock, flags); + return ret; +} +EXPORT_SYMBOL(ide_end_request); + +/* + * Power Management state machine. This one is rather trivial for now, + * we should probably add more, like switching back to PIO on suspend + * to help some BIOSes, re-do the door locking on resume, etc... + */ + +enum { + ide_pm_flush_cache = ide_pm_state_start_suspend, + idedisk_pm_standby, + + idedisk_pm_idle = ide_pm_state_start_resume, + ide_pm_restore_dma, +}; + +static void ide_complete_power_step(ide_drive_t *drive, struct request *rq, u8 stat, u8 error) +{ + if (drive->media != ide_disk) + return; + + switch (rq->pm->pm_step) { + case ide_pm_flush_cache: /* Suspend step 1 (flush cache) complete */ + if (rq->pm->pm_state == 4) + rq->pm->pm_step = ide_pm_state_completed; + else + rq->pm->pm_step = idedisk_pm_standby; + break; + case idedisk_pm_standby: /* Suspend step 2 (standby) complete */ + rq->pm->pm_step = ide_pm_state_completed; + break; + case idedisk_pm_idle: /* Resume step 1 (idle) complete */ + rq->pm->pm_step = ide_pm_restore_dma; + break; + } +} + +static ide_startstop_t ide_start_power_step(ide_drive_t *drive, struct request *rq) +{ + ide_task_t *args = rq->special; + + memset(args, 0, sizeof(*args)); + + if (drive->media != ide_disk) { + /* skip idedisk_pm_idle for ATAPI devices */ + if (rq->pm->pm_step == idedisk_pm_idle) + rq->pm->pm_step = ide_pm_restore_dma; + } + + switch (rq->pm->pm_step) { + case ide_pm_flush_cache: /* Suspend step 1 (flush cache) */ + if (drive->media != ide_disk) + break; + /* Not supported? Switch to next step now. */ + if (!drive->wcache || !ide_id_has_flush_cache(drive->id)) { + ide_complete_power_step(drive, rq, 0, 0); + return ide_stopped; + } + if (ide_id_has_flush_cache_ext(drive->id)) + args->tfRegister[IDE_COMMAND_OFFSET] = WIN_FLUSH_CACHE_EXT; + else + args->tfRegister[IDE_COMMAND_OFFSET] = WIN_FLUSH_CACHE; + args->command_type = IDE_DRIVE_TASK_NO_DATA; + args->handler = &task_no_data_intr; + return do_rw_taskfile(drive, args); + + case idedisk_pm_standby: /* Suspend step 2 (standby) */ + args->tfRegister[IDE_COMMAND_OFFSET] = WIN_STANDBYNOW1; + args->command_type = IDE_DRIVE_TASK_NO_DATA; + args->handler = &task_no_data_intr; + return do_rw_taskfile(drive, args); + + case idedisk_pm_idle: /* Resume step 1 (idle) */ + args->tfRegister[IDE_COMMAND_OFFSET] = WIN_IDLEIMMEDIATE; + args->command_type = IDE_DRIVE_TASK_NO_DATA; + args->handler = task_no_data_intr; + return do_rw_taskfile(drive, args); + + case ide_pm_restore_dma: /* Resume step 2 (restore DMA) */ + /* + * Right now, all we do is call hwif->ide_dma_check(drive), + * we could be smarter and check for current xfer_speed + * in struct drive etc... + */ + if ((drive->id->capability & 1) == 0) + break; + if (drive->hwif->ide_dma_check == NULL) + break; + drive->hwif->ide_dma_check(drive); + break; + } + rq->pm->pm_step = ide_pm_state_completed; + return ide_stopped; +} + +/** + * ide_complete_pm_request - end the current Power Management request + * @drive: target drive + * @rq: request + * + * This function cleans up the current PM request and stops the queue + * if necessary. + */ +static void ide_complete_pm_request (ide_drive_t *drive, struct request *rq) +{ + unsigned long flags; + +#ifdef DEBUG_PM + printk("%s: completing PM request, %s\n", drive->name, + blk_pm_suspend_request(rq) ? "suspend" : "resume"); +#endif + spin_lock_irqsave(&ide_lock, flags); + if (blk_pm_suspend_request(rq)) { + blk_stop_queue(drive->queue); + } else { + drive->blocked = 0; + blk_start_queue(drive->queue); + } + blkdev_dequeue_request(rq); + HWGROUP(drive)->rq = NULL; + end_that_request_last(rq); + spin_unlock_irqrestore(&ide_lock, flags); +} + +/* + * FIXME: probably move this somewhere else, name is bad too :) + */ +u64 ide_get_error_location(ide_drive_t *drive, char *args) +{ + u32 high, low; + u8 hcyl, lcyl, sect; + u64 sector; + + high = 0; + hcyl = args[5]; + lcyl = args[4]; + sect = args[3]; + + if (ide_id_has_flush_cache_ext(drive->id)) { + low = (hcyl << 16) | (lcyl << 8) | sect; + HWIF(drive)->OUTB(drive->ctl|0x80, IDE_CONTROL_REG); + high = ide_read_24(drive); + } else { + u8 cur = HWIF(drive)->INB(IDE_SELECT_REG); + if (cur & 0x40) { + high = cur & 0xf; + low = (hcyl << 16) | (lcyl << 8) | sect; + } else { + low = hcyl * drive->head * drive->sect; + low += lcyl * drive->sect; + low += sect - 1; + } + } + + sector = ((u64) high << 24) | low; + return sector; +} +EXPORT_SYMBOL(ide_get_error_location); + +/** + * 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_hwif_t *hwif = HWIF(drive); + unsigned long flags; + struct request *rq; + + spin_lock_irqsave(&ide_lock, flags); + rq = HWGROUP(drive)->rq; + spin_unlock_irqrestore(&ide_lock, flags); + + if (rq->flags & REQ_DRIVE_CMD) { + u8 *args = (u8 *) rq->buffer; + if (rq->errors == 0) + rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT); + + if (args) { + args[0] = stat; + args[1] = err; + args[2] = hwif->INB(IDE_NSECTOR_REG); + } + } else if (rq->flags & REQ_DRIVE_TASK) { + u8 *args = (u8 *) rq->buffer; + if (rq->errors == 0) + rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT); + + if (args) { + args[0] = stat; + args[1] = err; + args[2] = hwif->INB(IDE_NSECTOR_REG); + args[3] = hwif->INB(IDE_SECTOR_REG); + args[4] = hwif->INB(IDE_LCYL_REG); + args[5] = hwif->INB(IDE_HCYL_REG); + args[6] = hwif->INB(IDE_SELECT_REG); + } + } else if (rq->flags & REQ_DRIVE_TASKFILE) { + ide_task_t *args = (ide_task_t *) rq->special; + if (rq->errors == 0) + rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT); + + if (args) { + if (args->tf_in_flags.b.data) { + u16 data = hwif->INW(IDE_DATA_REG); + args->tfRegister[IDE_DATA_OFFSET] = (data) & 0xFF; + args->hobRegister[IDE_DATA_OFFSET] = (data >> 8) & 0xFF; + } + args->tfRegister[IDE_ERROR_OFFSET] = err; + /* be sure we're looking at the low order bits */ + hwif->OUTB(drive->ctl & ~0x80, IDE_CONTROL_REG); + args->tfRegister[IDE_NSECTOR_OFFSET] = hwif->INB(IDE_NSECTOR_REG); + args->tfRegister[IDE_SECTOR_OFFSET] = hwif->INB(IDE_SECTOR_REG); + args->tfRegister[IDE_LCYL_OFFSET] = hwif->INB(IDE_LCYL_REG); + args->tfRegister[IDE_HCYL_OFFSET] = hwif->INB(IDE_HCYL_REG); + args->tfRegister[IDE_SELECT_OFFSET] = hwif->INB(IDE_SELECT_REG); + args->tfRegister[IDE_STATUS_OFFSET] = stat; + + if (drive->addressing == 1) { + hwif->OUTB(drive->ctl|0x80, IDE_CONTROL_REG); + args->hobRegister[IDE_FEATURE_OFFSET] = hwif->INB(IDE_FEATURE_REG); + args->hobRegister[IDE_NSECTOR_OFFSET] = hwif->INB(IDE_NSECTOR_REG); + args->hobRegister[IDE_SECTOR_OFFSET] = hwif->INB(IDE_SECTOR_REG); + args->hobRegister[IDE_LCYL_OFFSET] = hwif->INB(IDE_LCYL_REG); + args->hobRegister[IDE_HCYL_OFFSET] = hwif->INB(IDE_HCYL_REG); + } + } + } else if (blk_pm_request(rq)) { +#ifdef DEBUG_PM + printk("%s: complete_power_step(step: %d, stat: %x, err: %x)\n", + drive->name, rq->pm->pm_step, stat, err); +#endif + ide_complete_power_step(drive, rq, stat, err); + if (rq->pm->pm_step == ide_pm_state_completed) + ide_complete_pm_request(drive, rq); + return; + } + + spin_lock_irqsave(&ide_lock, flags); + blkdev_dequeue_request(rq); + HWGROUP(drive)->rq = NULL; + rq->errors = err; + end_that_request_last(rq); + spin_unlock_irqrestore(&ide_lock, flags); +} + +EXPORT_SYMBOL(ide_end_drive_cmd); + +/** + * try_to_flush_leftover_data - flush junk + * @drive: drive to flush + * + * try_to_flush_leftover_data() is invoked in response to a drive + * unexpectedly having its DRQ_STAT bit set. As an alternative to + * resetting the drive, this routine tries to clear the condition + * by read a sector's worth of data from the drive. Of course, + * this may not help if the drive is *waiting* for data from *us*. + */ +static void try_to_flush_leftover_data (ide_drive_t *drive) +{ + int i = (drive->mult_count ? drive->mult_count : 1) * SECTOR_WORDS; + + if (drive->media != ide_disk) + return; + while (i > 0) { + u32 buffer[16]; + u32 wcount = (i > 16) ? 16 : i; + + i -= wcount; + HWIF(drive)->ata_input_data(drive, buffer, wcount); + } +} + +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 & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) { + /* other bits are useless when BUSY */ + rq->errors |= ERROR_RESET; + } else if (stat & ERR_STAT) { + /* err has different meaning on cdrom and tape */ + if (err == ABRT_ERR) { + if (drive->select.b.lba && + /* some newer drives don't support WIN_SPECIFY */ + hwif->INB(IDE_COMMAND_REG) == WIN_SPECIFY) + return ide_stopped; + } else if ((err & BAD_CRC) == BAD_CRC) { + /* UDMA crc error, just retry the operation */ + drive->crc_count++; + } else if (err & (BBD_ERR | ECC_ERR)) { + /* retries won't help these */ + rq->errors = ERROR_MAX; + } else if (err & TRK0_ERR) { + /* help it find track zero */ + rq->errors |= ERROR_RECAL; + } + } + + if ((stat & DRQ_STAT) && rq_data_dir(rq) == READ) + try_to_flush_leftover_data(drive); + + if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT)) + /* force an abort */ + hwif->OUTB(WIN_IDLEIMMEDIATE, IDE_COMMAND_REG); + + if (rq->errors >= ERROR_MAX || blk_noretry_request(rq)) + ide_kill_rq(drive, rq); + else { + 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 & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) { + /* other bits are useless when BUSY */ + rq->errors |= ERROR_RESET; + } else { + /* add decoding error stuff */ + } + + if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT)) + /* force an abort */ + hwif->OUTB(WIN_IDLEIMMEDIATE, IDE_COMMAND_REG); + + 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 (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK | REQ_DRIVE_TASKFILE)) { + 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); + +ide_startstop_t __ide_abort(ide_drive_t *drive, struct request *rq) +{ + if (drive->media != ide_disk) + rq->errors |= ERROR_RESET; + + ide_kill_rq(drive, rq); + + return ide_stopped; +} + +EXPORT_SYMBOL_GPL(__ide_abort); + +/** + * ide_abort - abort pending IDE operatins + * @drive: drive the error occurred on + * @msg: message to report + * + * ide_abort kills and cleans up when we are about to do a + * host initiated reset on active commands. Longer term we + * want handlers to have sensible abort handling themselves + * + * This differs fundamentally from ide_error because in + * this case the command is doing just fine when we + * blow it away. + */ + +ide_startstop_t ide_abort(ide_drive_t *drive, const char *msg) +{ + struct request *rq; + + if (drive == NULL || (rq = HWGROUP(drive)->rq) == NULL) + return ide_stopped; + + /* retry only "normal" I/O: */ + if (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK | REQ_DRIVE_TASKFILE)) { + rq->errors = 1; + ide_end_drive_cmd(drive, BUSY_STAT, 0); + return ide_stopped; + } + + if (rq->rq_disk) { + ide_driver_t *drv; + + drv = *(ide_driver_t **)rq->rq_disk->private_data; + return drv->abort(drive, rq); + } else + return __ide_abort(drive, rq); +} + +/** + * ide_cmd - issue a simple drive command + * @drive: drive the command is for + * @cmd: command byte + * @nsect: sector byte + * @handler: handler for the command completion + * + * Issue a simple drive command with interrupts. + * The drive must be selected beforehand. + */ + +static void ide_cmd (ide_drive_t *drive, u8 cmd, u8 nsect, + ide_handler_t *handler) +{ + ide_hwif_t *hwif = HWIF(drive); + if (IDE_CONTROL_REG) + hwif->OUTB(drive->ctl,IDE_CONTROL_REG); /* clear nIEN */ + SELECT_MASK(drive,0); + hwif->OUTB(nsect,IDE_NSECTOR_REG); + ide_execute_command(drive, cmd, handler, WAIT_CMD, NULL); +} + +/** + * drive_cmd_intr - drive command completion interrupt + * @drive: drive the completion interrupt occurred on + * + * drive_cmd_intr() is invoked on completion of a special DRIVE_CMD. + * We do any necessary daya reading and then wait for the drive to + * go non busy. At that point we may read the error data and complete + * the request + */ + +static ide_startstop_t drive_cmd_intr (ide_drive_t *drive) +{ + struct request *rq = HWGROUP(drive)->rq; + ide_hwif_t *hwif = HWIF(drive); + u8 *args = (u8 *) rq->buffer; + u8 stat = hwif->INB(IDE_STATUS_REG); + int retries = 10; + + local_irq_enable(); + if ((stat & DRQ_STAT) && args && args[3]) { + u8 io_32bit = drive->io_32bit; + drive->io_32bit = 0; + hwif->ata_input_data(drive, &args[4], args[3] * SECTOR_WORDS); + drive->io_32bit = io_32bit; + while (((stat = hwif->INB(IDE_STATUS_REG)) & BUSY_STAT) && retries--) + udelay(100); + } + + if (!OK_STAT(stat, READY_STAT, BAD_STAT)) + return ide_error(drive, "drive_cmd", stat); + /* calls ide_end_drive_cmd */ + ide_end_drive_cmd(drive, stat, hwif->INB(IDE_ERROR_REG)); + return ide_stopped; +} + +static void ide_init_specify_cmd(ide_drive_t *drive, ide_task_t *task) +{ + task->tfRegister[IDE_NSECTOR_OFFSET] = drive->sect; + task->tfRegister[IDE_SECTOR_OFFSET] = drive->sect; + task->tfRegister[IDE_LCYL_OFFSET] = drive->cyl; + task->tfRegister[IDE_HCYL_OFFSET] = drive->cyl>>8; + task->tfRegister[IDE_SELECT_OFFSET] = ((drive->head-1)|drive->select.all)&0xBF; + task->tfRegister[IDE_COMMAND_OFFSET] = WIN_SPECIFY; + + task->handler = &set_geometry_intr; +} + +static void ide_init_restore_cmd(ide_drive_t *drive, ide_task_t *task) +{ + task->tfRegister[IDE_NSECTOR_OFFSET] = drive->sect; + task->tfRegister[IDE_COMMAND_OFFSET] = WIN_RESTORE; + + task->handler = &recal_intr; +} + +static void ide_init_setmult_cmd(ide_drive_t *drive, ide_task_t *task) +{ + task->tfRegister[IDE_NSECTOR_OFFSET] = drive->mult_req; + task->tfRegister[IDE_COMMAND_OFFSET] = WIN_SETMULT; + + task->handler = &set_multmode_intr; +} + +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.command_type = IDE_DRIVE_TASK_NO_DATA; + + if (s->b.set_geometry) { + s->b.set_geometry = 0; + ide_init_specify_cmd(drive, &args); + } else if (s->b.recalibrate) { + s->b.recalibrate = 0; + ide_init_restore_cmd(drive, &args); + } else if (s->b.set_multmode) { + s->b.set_multmode = 0; + if (drive->mult_req > drive->id->max_multsect) + drive->mult_req = drive->id->max_multsect; + ide_init_setmult_cmd(drive, &args); + } 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; + } + + 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 WIN_SPECIFY, WIN_RESTORE, and WIN_SETMULT + * 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 (s->b.set_tune) { + s->b.set_tune = 0; + if (HWIF(drive)->tuneproc != NULL) + HWIF(drive)->tuneproc(drive, drive->tune_req); + return ide_stopped; + } else { + 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->flags & REQ_DRIVE_TASKFILE) == 0) { + 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 = hwif->cursg_ofs = 0; +} + +EXPORT_SYMBOL_GPL(ide_init_sg_cmd); + +/** + * execute_drive_command - issue special drive command + * @drive: the drive to issue th 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); + if (rq->flags & REQ_DRIVE_TASKFILE) { + ide_task_t *args = rq->special; + + if (!args) + goto done; + + hwif->data_phase = args->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; + } + + if (args->tf_out_flags.all != 0) + return flagged_taskfile(drive, args); + return do_rw_taskfile(drive, args); + } else if (rq->flags & REQ_DRIVE_TASK) { + u8 *args = rq->buffer; + u8 sel; + + if (!args) + goto done; +#ifdef DEBUG + printk("%s: DRIVE_TASK_CMD ", drive->name); + printk("cmd=0x%02x ", args[0]); + printk("fr=0x%02x ", args[1]); + printk("ns=0x%02x ", args[2]); + printk("sc=0x%02x ", args[3]); + printk("lcyl=0x%02x ", args[4]); + printk("hcyl=0x%02x ", args[5]); + printk("sel=0x%02x\n", args[6]); +#endif + hwif->OUTB(args[1], IDE_FEATURE_REG); + hwif->OUTB(args[3], IDE_SECTOR_REG); + hwif->OUTB(args[4], IDE_LCYL_REG); + hwif->OUTB(args[5], IDE_HCYL_REG); + sel = (args[6] & ~0x10); + if (drive->select.b.unit) + sel |= 0x10; + hwif->OUTB(sel, IDE_SELECT_REG); + ide_cmd(drive, args[0], args[2], &drive_cmd_intr); + return ide_started; + } else if (rq->flags & REQ_DRIVE_CMD) { + u8 *args = rq->buffer; + + if (!args) + goto done; +#ifdef DEBUG + printk("%s: DRIVE_CMD ", drive->name); + printk("cmd=0x%02x ", args[0]); + printk("sc=0x%02x ", args[1]); + printk("fr=0x%02x ", args[2]); + printk("xx=0x%02x\n", args[3]); +#endif + if (args[0] == WIN_SMART) { + hwif->OUTB(0x4f, IDE_LCYL_REG); + hwif->OUTB(0xc2, IDE_HCYL_REG); + hwif->OUTB(args[2],IDE_FEATURE_REG); + hwif->OUTB(args[1],IDE_SECTOR_REG); + ide_cmd(drive, args[0], args[3], &drive_cmd_intr); + return ide_started; + } + hwif->OUTB(args[2],IDE_FEATURE_REG); + ide_cmd(drive, args[0], args[1], &drive_cmd_intr); + return ide_started; + } + +done: + /* + * 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->INB(IDE_STATUS_REG), + hwif->INB(IDE_ERROR_REG)); + 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. It also does + * the final remapping for weird stuff like EZDrive. Once + * device mapper can work sector level the EZDrive stuff can go away + * + * FIXME: this function needs a rename + */ + +static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq) +{ + ide_startstop_t startstop; + sector_t block; + + BUG_ON(!(rq->flags & REQ_STARTED)); + +#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)) { + goto kill_rq; + } + + block = rq->sector; + if (blk_fs_request(rq) && + (drive->media == ide_disk || drive->media == ide_floppy)) { + block += drive->sect0; + } + /* Yecch - this will shift the entire interval, + possibly killing some innocent following sector */ + if (block == 0 && drive->remap_0_to_1 == 1) + block = 1; /* redirect MBR access to EZ-Drive partn table */ + + if (blk_pm_suspend_request(rq) && + rq->pm->pm_step == ide_pm_state_start_suspend) + /* Mark drive blocked when starting the suspend sequence. */ + drive->blocked = 1; + else if (blk_pm_resume_request(rq) && + rq->pm->pm_step == ide_pm_state_start_resume) { + /* + * The first thing we do on wakeup is to wait for BSY bit to + * go away (with a looong timeout) as a drive on this hwif may + * just be POSTing itself. + * We do that before even selecting as the "other" device on + * the bus may be broken enough to walk on our toes at this + * point. + */ + int rc; +#ifdef DEBUG_PM + printk("%s: Wakeup request inited, waiting for !BSY...\n", drive->name); +#endif + rc = ide_wait_not_busy(HWIF(drive), 35000); + if (rc) + printk(KERN_WARNING "%s: bus not ready on wakeup\n", drive->name); + SELECT_DRIVE(drive); + HWIF(drive)->OUTB(8, HWIF(drive)->io_ports[IDE_CONTROL_OFFSET]); + rc = ide_wait_not_busy(HWIF(drive), 10000); + if (rc) + printk(KERN_WARNING "%s: drive not ready on wakeup\n", drive->name); + } + + SELECT_DRIVE(drive); + if (ide_wait_stat(&startstop, drive, drive->ready_stat, BUSY_STAT|DRQ_STAT, WAIT_READY)) { + printk(KERN_ERR "%s: drive not ready for command\n", drive->name); + return startstop; + } + if (!drive->special.all) { + ide_driver_t *drv; + + if (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK)) + return execute_drive_cmd(drive, rq); + else if (rq->flags & REQ_DRIVE_TASKFILE) + return execute_drive_cmd(drive, rq); + else if (blk_pm_request(rq)) { +#ifdef DEBUG_PM + printk("%s: start_power_step(step: %d)\n", + drive->name, rq->pm->pm_step); +#endif + startstop = ide_start_power_step(drive, rq); + if (startstop == ide_stopped && + rq->pm->pm_step == ide_pm_state_completed) + ide_complete_pm_request(drive, rq); + return startstop; + } + + drv = *(ide_driver_t **)rq->rq_disk->private_data; + return drv->do_request(drive, rq, block); + } + 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->sleeping = 1; +} + +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 { + if ((!drive->sleeping || time_after_eq(jiffies, drive->sleep)) + && !elv_queue_empty(drive->queue)) { + if (!best + || (drive->sleeping && (!best->sleeping || time_before(drive->sleep, best->sleep))) + || (!best->sleeping && time_before(WAKEUP(drive), WAKEUP(best)))) + { + if (!blk_queue_plugged(drive->queue)) + best = drive; + } + } + } while ((drive = drive->next) != hwgroup->drive); + if (best && best->nice1 && !best->sleeping && 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->sleeping + && 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(&ide_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 the single global ide_lock 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 ide_lock (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. + */ +static void ide_do_request (ide_hwgroup_t *hwgroup, int masked_irq) +{ + ide_drive_t *drive; + ide_hwif_t *hwif; + struct request *rq; + ide_startstop_t startstop; + + /* for atari only: POSSIBLY BROKEN HERE(?) */ + ide_get_lock(ide_intr, hwgroup); + + /* caller must own ide_lock */ + BUG_ON(!irqs_disabled()); + + while (!hwgroup->busy) { + hwgroup->busy = 1; + 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->sleeping && (!sleeping || 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; + 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) */ + return; + } + hwif = HWIF(drive); + if (hwgroup->hwif->sharing_irq && + hwif != hwgroup->hwif && + hwif->io_ports[IDE_CONTROL_OFFSET]) { + /* set nIEN for previous hwif */ + SELECT_INTERRUPT(drive); + } + hwgroup->hwif = hwif; + hwgroup->drive = drive; + drive->sleeping = 0; + drive->service_start = jiffies; + + if (blk_queue_plugged(drive->queue)) { + printk(KERN_ERR "ide: huh? queue was plugged!\n"); + break; + } + + /* + * 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->blocked && !blk_pm_request(rq) && !(rq->flags & REQ_PREEMPT)) { + /* We clear busy, there should be no pending ATA command at this point. */ + hwgroup->busy = 0; + break; + } + + hwgroup->rq = rq; + + /* + * Some systems have trouble with IDE IRQs arriving while + * the driver is still setting things up. So, here we disable + * the IRQ used by this interface while the request is being started. + * This may look bad at first, but pretty much the same thing + * happens anyway when any interrupt comes in, IDE or otherwise + * -- the kernel masks the IRQ while it is being handled. + */ + if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq) + disable_irq_nosync(hwif->irq); + spin_unlock(&ide_lock); + local_irq_enable(); + /* allow other IRQs while we start this request */ + startstop = start_request(drive, rq); + spin_lock_irq(&ide_lock); + if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq) + enable_irq(hwif->irq); + if (startstop == ide_stopped) + hwgroup->busy = 0; + } +} + +/* + * Passes the stuff to ide_do_request + */ +void do_ide_request(request_queue_t *q) +{ + ide_drive_t *drive = q->queuedata; + + ide_do_request(HWGROUP(drive), IDE_NO_IRQ); +} + +/* + * 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(drive)->ide_dma_end(drive); + ret = ide_error(drive, "dma timeout error", + hwif->INB(IDE_STATUS_REG)); + } else { + printk(KERN_WARNING "%s: DMA timeout retry\n", drive->name); + (void) hwif->ide_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->retry_pio++; + drive->state = DMA_PIO_RETRY; + (void) hwif->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; + 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(&ide_lock, flags); + + if ((handler = hwgroup->handler) == NULL) { + /* + * 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; + add_timer(&hwgroup->timer); + spin_unlock_irqrestore(&ide_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(&ide_lock); + hwif = HWIF(drive); +#if DISABLE_IRQ_NOSYNC + disable_irq_nosync(hwif->irq); +#else + /* disable_irq_nosync ?? */ + disable_irq(hwif->irq); +#endif /* DISABLE_IRQ_NOSYNC */ + /* 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) + (void) hwgroup->hwif->ide_dma_lostirq(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->INB(IDE_STATUS_REG)); + } + drive->service_time = jiffies - drive->service_start; + spin_lock_irq(&ide_lock); + enable_irq(hwif->irq); + if (startstop == ide_stopped) + hwgroup->busy = 0; + } + } + ide_do_request(hwgroup, IDE_NO_IRQ); + spin_unlock_irqrestore(&ide_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->INB(hwif->io_ports[IDE_STATUS_OFFSET]); + if (!OK_STAT(stat, READY_STAT, 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, struct pt_regs *regs) +{ + unsigned long flags; + ide_hwgroup_t *hwgroup = (ide_hwgroup_t *)dev_id; + ide_hwif_t *hwif; + ide_drive_t *drive; + ide_handler_t *handler; + ide_startstop_t startstop; + + spin_lock_irqsave(&ide_lock, flags); + hwif = hwgroup->hwif; + + if (!ide_ack_intr(hwif)) { + spin_unlock_irqrestore(&ide_lock, flags); + return IRQ_NONE; + } + + 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->pci_dev && !hwif->pci_dev->vendor) +#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->INB(hwif->io_ports[IDE_STATUS_OFFSET]); +#endif /* CONFIG_BLK_DEV_IDEPCI */ + } + spin_unlock_irqrestore(&ide_lock, flags); + return IRQ_NONE; + } + 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] + */ + spin_unlock_irqrestore(&ide_lock, flags); + return IRQ_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. + */ + spin_unlock_irqrestore(&ide_lock, flags); + return IRQ_NONE; + } + if (!hwgroup->busy) { + hwgroup->busy = 1; /* paranoia */ + printk(KERN_ERR "%s: ide_intr: hwgroup->busy was 0 ??\n", drive->name); + } + hwgroup->handler = NULL; + del_timer(&hwgroup->timer); + spin_unlock(&ide_lock); + + if (drive->unmask) + local_irq_enable(); + /* service this interrupt, may set handler for next interrupt */ + startstop = handler(drive); + spin_lock_irq(&ide_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; + ide_do_request(hwgroup, hwif->irq); + } else { + printk(KERN_ERR "%s: ide_intr: huh? expected NULL handler " + "on exit\n", drive->name); + } + } + spin_unlock_irqrestore(&ide_lock, flags); + return IRQ_HANDLED; +} + +/** + * ide_init_drive_cmd - initialize a drive command request + * @rq: request object + * + * Initialize a request before we fill it in and send it down to + * ide_do_drive_cmd. Commands must be set up by this function. Right + * now it doesn't do a lot, but if that changes abusers will have a + * nasty suprise. + */ + +void ide_init_drive_cmd (struct request *rq) +{ + memset(rq, 0, sizeof(*rq)); + rq->flags = REQ_DRIVE_CMD; + rq->ref_count = 1; +} + +EXPORT_SYMBOL(ide_init_drive_cmd); + +/** + * ide_do_drive_cmd - issue IDE special command + * @drive: device to issue command + * @rq: request to issue + * @action: action for processing + * + * This function issues a special IDE device request + * onto the request queue. + * + * If action is ide_wait, then the rq is queued at the end of the + * request queue, and the function sleeps until it has been processed. + * This is for use when invoked from an ioctl handler. + * + * If action is ide_preempt, then 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. + * + * If action is ide_next, then the rq is queued immediately after + * the currently-being-processed-request (if any), and the function + * returns without waiting for the new rq to be completed. As above, + * This is VERY DANGEROUS, and is intended for careful use by the + * ATAPI tape/cdrom driver code. + * + * If action is ide_end, then the rq is queued at the end of the + * request queue, and the function returns immediately without waiting + * for the new rq to be completed. This is again intended for careful + * use by the ATAPI tape/cdrom driver code. + */ + +int ide_do_drive_cmd (ide_drive_t *drive, struct request *rq, ide_action_t action) +{ + unsigned long flags; + ide_hwgroup_t *hwgroup = HWGROUP(drive); + DECLARE_COMPLETION(wait); + int where = ELEVATOR_INSERT_BACK, err; + int must_wait = (action == ide_wait || action == ide_head_wait); + + rq->errors = 0; + rq->rq_status = RQ_ACTIVE; + + /* + * we need to hold an extra reference to request for safe inspection + * after completion + */ + if (must_wait) { + rq->ref_count++; + rq->waiting = &wait; + rq->end_io = blk_end_sync_rq; + } + + spin_lock_irqsave(&ide_lock, flags); + if (action == ide_preempt) + hwgroup->rq = NULL; + if (action == ide_preempt || action == ide_head_wait) { + where = ELEVATOR_INSERT_FRONT; + rq->flags |= REQ_PREEMPT; + } + __elv_add_request(drive->queue, rq, where, 0); + ide_do_request(hwgroup, IDE_NO_IRQ); + spin_unlock_irqrestore(&ide_lock, flags); + + err = 0; + if (must_wait) { + wait_for_completion(&wait); + rq->waiting = NULL; + if (rq->errors) + err = -EIO; + + blk_put_request(rq); + } + + return err; +} + +EXPORT_SYMBOL(ide_do_drive_cmd); |