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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/ide/ide-io.c
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/ide/ide-io.c')
-rw-r--r--drivers/ide/ide-io.c1681
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);