AcoSail/kernel_optimize_test
8
0
Fork 0
forked from luck/tmp_suning_uos_patched
Code Pull Requests Activity
5e8d780d74
kernel_optimize_test/drivers/ide/ide-io.c
Alan Cox da574af755 [PATCH] ide: fix error handling for drives which clear the FIFO on error 
If the controller FIFO cleared automatically on error we must not try
and drain it as this will hang some chips.

Based in concept on a broken patch from -mm some while back

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-28 14:59:06 -07:00

1751 lines
50 KiB
C
Raw Blame History

/*
* 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>
static 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);
blkdev_dequeue_request(rq);
HWGROUP(drive)->rq = NULL;
end_that_request_last(rq, uptodate);
ret = 0;
}
return ret;
}
/**
* ide_end_request - complete an IDE I/O
* @drive: IDE device for the I/O
* @uptodate:
* @nr_sectors: number of sectors completed
*
* This is our end_request wrapper function. We complete the I/O
* update random number input and dequeue the request, which if
* it was tagged may be out of order.
*/
int ide_end_request (ide_drive_t *drive, int uptodate, int nr_sectors)
{
struct request *rq;
unsigned long flags;
int ret = 1;
/*
* room for locking improvements here, the calls below don't
* need the queue lock held at all
*/
spin_lock_irqsave(&ide_lock, flags);
rq = HWGROUP(drive)->rq;
if (!nr_sectors)
nr_sectors = rq->hard_cur_sectors;
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)
{
struct request_pm_state *pm = rq->end_io_data;
if (drive->media != ide_disk)
return;
switch (pm->pm_step) {
case ide_pm_flush_cache: /* Suspend step 1 (flush cache) complete */
if (pm->pm_state == PM_EVENT_FREEZE)
pm->pm_step = ide_pm_state_completed;
else
pm->pm_step = idedisk_pm_standby;
break;
case idedisk_pm_standby: /* Suspend step 2 (standby) complete */
pm->pm_step = ide_pm_state_completed;
break;
case idedisk_pm_idle: /* Resume step 1 (idle) complete */
pm->pm_step = ide_pm_restore_dma;
break;
}
}
static ide_startstop_t ide_start_power_step(ide_drive_t *drive, struct request *rq)
{
struct request_pm_state *pm = rq->end_io_data;
ide_task_t *args = rq->special;
memset(args, 0, sizeof(*args));
if (drive->media != ide_disk) {
/* skip idedisk_pm_idle for ATAPI devices */
if (pm->pm_step == idedisk_pm_idle)
pm->pm_step = ide_pm_restore_dma;
}
switch (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;
}
pm->pm_step = ide_pm_state_completed;
return ide_stopped;
}
/**
* ide_end_dequeued_request - complete an IDE I/O
* @drive: IDE device for the I/O
* @uptodate:
* @nr_sectors: number of sectors completed
*
* Complete an I/O that is no longer on the request queue. This
* typically occurs when we pull the request and issue a REQUEST_SENSE.
* We must still finish the old request but we must not tamper with the
* queue in the meantime.
*
* NOTE: This path does not handle barrier, but barrier is not supported
* on ide-cd anyway.
*/
int ide_end_dequeued_request(ide_drive_t *drive, struct request *rq,
int uptodate, int nr_sectors)
{
unsigned long flags;
int ret = 1;
spin_lock_irqsave(&ide_lock, flags);
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);
end_that_request_last(rq, uptodate);
ret = 0;
}
spin_unlock_irqrestore(&ide_lock, flags);
return ret;
}
EXPORT_SYMBOL_GPL(ide_end_dequeued_request);
/**
* 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, 1);
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)) {
struct request_pm_state *pm = rq->end_io_data;
#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 (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, !rq->errors);
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 && hwif->err_stops_fifo == 0)
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 operations
* @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 data 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 the command on
* @rq: the request structure holding the command
*
* execute_drive_cmd() issues a special drive command, usually
* initiated by ioctl() from the external hdparm program. The
* command can be a drive command, drive task or taskfile
* operation. Weirdly you can call it with NULL to wait for
* all commands to finish. Don't do this as that is due to change
*/
static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
struct request *rq)
{
ide_hwif_t *hwif = HWIF(drive);
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;
}
static void ide_check_pm_state(ide_drive_t *drive, struct request *rq)
{
struct request_pm_state *pm = rq->end_io_data;
if (blk_pm_suspend_request(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) &&
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), 100000);
if (rc)
printk(KERN_WARNING "%s: drive not ready on wakeup\n", drive->name);
}
}
/**
* 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_request(rq))
ide_check_pm_state(drive, rq);
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)) {
struct request_pm_state *pm = rq->end_io_data;
#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 &&
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;
int loops = 0;
/* 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;
}
again:
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.
*
* We count how many times we loop here to make sure we service
* all drives in the hwgroup without looping for ever
*/
if (drive->blocked && !blk_pm_request(rq) && !(rq->flags & REQ_PREEMPT)) {
drive = drive->next ? drive->next : hwgroup->drive;
if (loops++ < 4 && !blk_queue_plugged(drive->queue))
goto again;
/* 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 surprise.
*/
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_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);
View Git Blame Copy Permalink