/*
* IDE I/O functions
*
* Basic PIO and command management functionality.
*
* This code was split off from ide.c. See ide.c for history and original
* copyrights.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2, or (at your option) any
* later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* For the avoidance of doubt the "preferred form" of this code is one which
* is in an open non patent encumbered format. Where cryptographic key signing
* forms part of the process of creating an executable the information
* including keys needed to generate an equivalently functional executable
* are deemed to be part of the source code.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/major.h>
#include <linux/errno.h>
#include <linux/genhd.h>
#include <linux/blkpg.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/ide.h>
#include <linux/completion.h>
#include <linux/reboot.h>
#include <linux/cdrom.h>
#include <linux/seq_file.h>
#include <linux/device.h>
#include <linux/kmod.h>
#include <linux/scatterlist.h>
#include <linux/bitops.h>
#include <asm/byteorder.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <asm/io.h>
int ide_end_rq(ide_drive_t *drive, struct request *rq, int error,
unsigned int nr_bytes)
{
/*
* decide whether to reenable DMA -- 3 is a random magic for now,
* if we DMA timeout more than 3 times, just stay in PIO
*/
if ((drive->dev_flags & IDE_DFLAG_DMA_PIO_RETRY) &&
drive->retry_pio <= 3) {
drive->dev_flags &= ~IDE_DFLAG_DMA_PIO_RETRY;
ide_dma_on(drive);
}
return blk_end_request(rq, error, nr_bytes);
}
EXPORT_SYMBOL_GPL(ide_end_rq);
void ide_complete_cmd(ide_drive_t *drive, struct ide_cmd *cmd, u8 stat, u8 err)
{
const struct ide_tp_ops *tp_ops = drive->hwif->tp_ops;
struct ide_taskfile *tf = &cmd->tf;
struct request *rq = cmd->rq;
u8 tf_cmd = tf->command;
tf->error = err;
tf->status = stat;
if (cmd->ftf_flags & IDE_FTFLAG_IN_DATA) {
u8 data[2];
tp_ops->input_data(drive, cmd, data, 2);
cmd->tf.data = data[0];
cmd->hob.data = data[1];
}
ide_tf_readback(drive, cmd);
if ((cmd->tf_flags & IDE_TFLAG_CUSTOM_HANDLER) &&
tf_cmd == ATA_CMD_IDLEIMMEDIATE) {
if (tf->lbal != 0xc4) {
printk(KERN_ERR "%s: head unload failed!\n",
drive->name);
ide_tf_dump(drive->name, cmd);
} else
drive->dev_flags |= IDE_DFLAG_PARKED;
}
if (rq && rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
struct ide_cmd *orig_cmd = rq->special;
if (cmd->tf_flags & IDE_TFLAG_DYN)
kfree(orig_cmd);
else
memcpy(orig_cmd, cmd, sizeof(*cmd));
}
}
int ide_complete_rq(ide_drive_t *drive, int error, unsigned int nr_bytes)
{
ide_hwif_t *hwif = drive->hwif;
struct request *rq = hwif->rq;
int rc;
/*
* if failfast is set on a request, override number of sectors
* and complete the whole request right now
*/
if (blk_noretry_request(rq) && error <= 0)
nr_bytes = blk_rq_sectors(rq) << 9;
rc = ide_end_rq(drive, rq, error, nr_bytes);
if (rc == 0)
hwif->rq = NULL;
return rc;
}
EXPORT_SYMBOL(ide_complete_rq);
void ide_kill_rq(ide_drive_t *drive, struct request *rq)
{
u8 drv_req = (rq->cmd_type == REQ_TYPE_SPECIAL) && rq->rq_disk;
u8 media = drive->media;
drive->failed_pc = NULL;
if ((media == ide_floppy || media == ide_tape) && drv_req) {
rq->errors = 0;
} else {
if (media == ide_tape)
rq->errors = IDE_DRV_ERROR_GENERAL;
else if (rq->cmd_type != REQ_TYPE_FS && rq->errors == 0)
rq->errors = -EIO;
}
ide_complete_rq(drive, -EIO, blk_rq_bytes(rq));
}
static void ide_tf_set_specify_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
{
tf->nsect = drive->sect;
tf->lbal = drive->sect;
tf->lbam = drive->cyl;
tf->lbah = drive->cyl >> 8;
tf->device = (drive->head - 1) | drive->select;
tf->command = ATA_CMD_INIT_DEV_PARAMS;
}
static void ide_tf_set_restore_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
{
tf->nsect = drive->sect;
tf->command = ATA_CMD_RESTORE;
}
static void ide_tf_set_setmult_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
{
tf->nsect = drive->mult_req;
tf->command = ATA_CMD_SET_MULTI;
}
/**
* do_special - issue some special commands
* @drive: drive the command is for
*
* do_special() is used to issue ATA_CMD_INIT_DEV_PARAMS,
* ATA_CMD_RESTORE and ATA_CMD_SET_MULTI commands to a drive.
*/
static ide_startstop_t do_special(ide_drive_t *drive)
{
struct ide_cmd cmd;
#ifdef DEBUG
printk(KERN_DEBUG "%s: %s: 0x%02x\n", drive->name, __func__,
drive->special_flags);
#endif
if (drive->media != ide_disk) {
drive->special_flags = 0;
drive->mult_req = 0;
return ide_stopped;
}
memset(&cmd, 0, sizeof(cmd));
cmd.protocol = ATA_PROT_NODATA;
if (drive->special_flags & IDE_SFLAG_SET_GEOMETRY) {
drive->special_flags &= ~IDE_SFLAG_SET_GEOMETRY;
ide_tf_set_specify_cmd(drive, &cmd.tf);
} else if (drive->special_flags & IDE_SFLAG_RECALIBRATE) {
drive->special_flags &= ~IDE_SFLAG_RECALIBRATE;
ide_tf_set_restore_cmd(drive, &cmd.tf);
} else if (drive->special_flags & IDE_SFLAG_SET_MULTMODE) {
drive->special_flags &= ~IDE_SFLAG_SET_MULTMODE;
ide_tf_set_setmult_cmd(drive, &cmd.tf);
} else
BUG();
cmd.valid.out.tf = IDE_VALID_OUT_TF | IDE_VALID_DEVICE;
cmd.valid.in.tf = IDE_VALID_IN_TF | IDE_VALID_DEVICE;
cmd.tf_flags = IDE_TFLAG_CUSTOM_HANDLER;
do_rw_taskfile(drive, &cmd);
return ide_started;
}
void ide_map_sg(ide_drive_t *drive, struct ide_cmd *cmd)
{
ide_hwif_t *hwif = drive->hwif;
struct scatterlist *sg = hwif->sg_table;
struct request *rq = cmd->rq;
cmd->sg_nents = blk_rq_map_sg(drive->queue, rq, sg);
}
EXPORT_SYMBOL_GPL(ide_map_sg);
void ide_init_sg_cmd(struct ide_cmd *cmd, unsigned int nr_bytes)
{
cmd->nbytes = cmd->nleft = nr_bytes;
cmd->cursg_ofs = 0;
cmd->cursg = NULL;
}
EXPORT_SYMBOL_GPL(ide_init_sg_cmd);
/**
* execute_drive_command - issue special drive command
* @drive: the drive to issue the command on
* @rq: the request structure holding the command
*
* execute_drive_cmd() issues a special drive command, usually
* initiated by ioctl() from the external hdparm program. The
* command can be a drive command, drive task or taskfile
* operation. Weirdly you can call it with NULL to wait for
* all commands to finish. Don't do this as that is due to change
*/
static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
struct request *rq)
{
struct ide_cmd *cmd = rq->special;
if (cmd) {
if (cmd->protocol == ATA_PROT_PIO) {
ide_init_sg_cmd(cmd, blk_rq_sectors(rq) << 9);
ide_map_sg(drive, cmd);
}
return do_rw_taskfile(drive, cmd);
}
/*
* 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
rq->errors = 0;
ide_complete_rq(drive, 0, blk_rq_bytes(rq));
return ide_stopped;
}
static ide_startstop_t ide_special_rq(ide_drive_t *drive, struct request *rq)
{
u8 cmd = rq->cmd[0];
switch (cmd) {
case REQ_PARK_HEADS:
case REQ_UNPARK_HEADS:
return ide_do_park_unpark(drive, rq);
case REQ_DEVSET_EXEC:
return ide_do_devset(drive, rq);
case REQ_DRIVE_RESET:
return ide_do_reset(drive);
default:
BUG();
}
}
/**
* start_request - start of I/O and command issuing for IDE
*
* start_request() initiates handling of a new I/O request. It
* accepts commands and I/O (read/write) requests.
*
* FIXME: this function needs a rename
*/
static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
{
ide_startstop_t startstop;
BUG_ON(!(rq->cmd_flags & REQ_STARTED));
#ifdef DEBUG
printk("%s: start_request: current=0x%08lx\n",
drive->hwif->name, (unsigned long) rq);
#endif
/* bail early if we've exceeded max_failures */
if (drive->max_failures && (drive->failures > drive->max_failures)) {
rq->cmd_flags |= REQ_FAILED;
goto kill_rq;
}
if (blk_pm_request(rq))
ide_check_pm_state(drive, rq);
drive->hwif->tp_ops->dev_select(drive);
if (ide_wait_stat(&startstop, drive, drive->ready_stat,
ATA_BUSY | ATA_DRQ, WAIT_READY)) {
printk(KERN_ERR "%s: drive not ready for command\n", drive->name);
return startstop;
}
if (drive->special_flags == 0) {
struct ide_driver *drv;
/*
* We reset the drive so we need to issue a SETFEATURES.
* Do it _after_ do_special() restored device parameters.
*/
if (drive->current_speed == 0xff)
ide_config_drive_speed(drive, drive->desired_speed);
if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE)
return execute_drive_cmd(drive, rq);
else if (blk_pm_request(rq)) {
struct request_pm_state *pm = rq->special;
#ifdef DEBUG_PM
printk("%s: start_power_step(step: %d)\n",
drive->name, pm->pm_step);
#endif
startstop = ide_start_power_step(drive, rq);
if (startstop == ide_stopped &&
pm->pm_step == IDE_PM_COMPLETED)
ide_complete_pm_rq(drive, rq);
return startstop;
} else if (!rq->rq_disk && rq->cmd_type == REQ_TYPE_SPECIAL)
/*
* TODO: Once all ULDs have been modified to
* check for specific op codes rather than
* blindly accepting any special request, the
* check for ->rq_disk above may be replaced
* by a more suitable mechanism or even
* dropped entirely.
*/
return ide_special_rq(drive, rq);
drv = *(struct ide_driver **)rq->rq_disk->private_data;
return drv->do_request(drive, rq, blk_rq_pos(rq));
}
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 port by sleeping for timeout jiffies.
*/
void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
{
if (timeout > WAIT_WORSTCASE)
timeout = WAIT_WORSTCASE;
drive->sleep = timeout + jiffies;
drive->dev_flags |= IDE_DFLAG_SLEEPING;
}
EXPORT_SYMBOL(ide_stall_queue);
static inline int ide_lock_port(ide_hwif_t *hwif)
{
if (hwif->busy)
return 1;
hwif->busy = 1;
return 0;
}
static inline void ide_unlock_port(ide_hwif_t *hwif)
{
hwif->busy = 0;
}
static inline int ide_lock_host(struct ide_host *host, ide_hwif_t *hwif)
{
int rc = 0;
if (host->host_flags & IDE_HFLAG_SERIALIZE) {
rc = test_and_set_bit_lock(IDE_HOST_BUSY, &host->host_busy);
if (rc == 0) {
if (host->get_lock)
host->get_lock(ide_intr, hwif);
}
}
return rc;
}
static inline void ide_unlock_host(struct ide_host *host)
{
if (host->host_flags & IDE_HFLAG_SERIALIZE) {
if (host->release_lock)
host->release_lock();
clear_bit_unlock(IDE_HOST_BUSY, &host->host_busy);
}
}
static void __ide_requeue_and_plug(struct request_queue *q, struct request *rq)
{
if (rq)
blk_requeue_request(q, rq);
if (rq || blk_peek_request(q)) {
/* Use 3ms as that was the old plug delay */
blk_delay_queue(q, 3);
}
}
void ide_requeue_and_plug(ide_drive_t *drive, struct request *rq)
{
struct request_queue *q = drive->queue;
unsigned long flags;
spin_lock_irqsave(q->queue_lock, flags);
__ide_requeue_and_plug(q, rq);
spin_unlock_irqrestore(q->queue_lock, flags);
}
/*
* Issue a new request to a device.
*/
void do_ide_request(struct request_queue *q)
{
ide_drive_t *drive = q->queuedata;
ide_hwif_t *hwif = drive->hwif;
struct ide_host *host = hwif->host;
struct request *rq = NULL;
ide_startstop_t startstop;
unsigned long queue_run_ms = 3; /* old plug delay */
spin_unlock_irq(q->queue_lock);
/* HLD do_request() callback might sleep, make sure it's okay */
might_sleep();
if (ide_lock_host(host, hwif))
goto plug_device_2;
spin_lock_irq(&hwif->lock);
if (!ide_lock_port(hwif)) {
ide_hwif_t *prev_port;
WARN_ON_ONCE(hwif->rq);
repeat:
prev_port = hwif->host->cur_port;
if (drive->dev_flags & IDE_DFLAG_SLEEPING &&
time_after(drive->sleep, jiffies)) {
unsigned long left = jiffies - drive->sleep;
queue_run_ms = jiffies_to_msecs(left + 1);
ide_unlock_port(hwif);
goto plug_device;
}
if ((hwif->host->host_flags & IDE_HFLAG_SERIALIZE) &&
hwif != prev_port) {
ide_drive_t *cur_dev =
prev_port ? prev_port->cur_dev : NULL;
/*
* set nIEN for previous port, drives in the
* quirk list may not like intr setups/cleanups
*/
if (cur_dev &&
(cur_dev->dev_flags & IDE_DFLAG_NIEN_QUIRK) == 0)
prev_port->tp_ops->write_devctl(prev_port,
ATA_NIEN |
ATA_DEVCTL_OBS);
hwif->host->cur_port = hwif;
}
hwif->cur_dev = drive;
drive->dev_flags &= ~(IDE_DFLAG_SLEEPING | IDE_DFLAG_PARKED);
spin_unlock_irq(&hwif->lock);
spin_lock_irq(q->queue_lock);
/*
* we know that the queue isn't empty, but this can happen
* if the q->prep_rq_fn() decides to kill a request
*/
if (!rq)
rq = blk_fetch_request(drive->queue);
spin_unlock_irq(q->queue_lock);
spin_lock_irq(&hwif->lock);
if (!rq) {
ide_unlock_port(hwif);
goto out;
}
/*
* Sanity: don't accept a request that isn't a PM request
* if we are currently power managed. This is very important as
* blk_stop_queue() doesn't prevent the blk_fetch_request()
* above to return us whatever is in the queue. Since we call
* ide_do_request() ourselves, we end up taking requests while
* the queue is blocked...
*
* We let requests forced at head of queue with ide-preempt
* though. I hope that doesn't happen too much, hopefully not
* unless the subdriver triggers such a thing in its own PM
* state machine.
*/
if ((drive->dev_flags & IDE_DFLAG_BLOCKED) &&
blk_pm_request(rq) == 0 &&
(rq->cmd_flags & REQ_PREEMPT) == 0) {
/* there should be no pending command at this point */
ide_unlock_port(hwif);
goto plug_device;
}
hwif->rq = rq;
spin_unlock_irq(&hwif->lock);
startstop = start_request(drive, rq);
spin_lock_irq(&hwif->lock);
if (startstop == ide_stopped) {
rq = hwif->rq;
hwif->rq = NULL;
goto repeat;
}
} else
goto plug_device;
out:
spin_unlock_irq(&hwif->lock);
if (rq == NULL)
ide_unlock_host(host);
spin_lock_irq(q->queue_lock);
return;
plug_device:
spin_unlock_irq(&hwif->lock);
ide_unlock_host(host);
plug_device_2:
spin_lock_irq(q->queue_lock);
__ide_requeue_and_plug(q, rq);
}
static int drive_is_ready(ide_drive_t *drive)
{
ide_hwif_t *hwif = drive->hwif;
u8 stat = 0;
if (drive->waiting_for_dma)
return hwif->dma_ops->dma_test_irq(drive);
if (hwif->io_ports.ctl_addr &&
(hwif->host_flags & IDE_HFLAG_BROKEN_ALTSTATUS) == 0)
stat = hwif->tp_ops->read_altstatus(hwif);
else
/* Note: this may clear a pending IRQ!! */
stat = hwif->tp_ops->read_status(hwif);
if (stat & ATA_BUSY)
/* drive busy: definitely not interrupting */
return 0;
/* drive ready: *might* be interrupting */
return 1;
}
/**
* ide_timer_expiry - handle lack of an IDE interrupt
* @data: timer callback magic (hwif)
*
* 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_hwif_t *hwif = (ide_hwif_t *)data;
ide_drive_t *uninitialized_var(drive);
ide_handler_t *handler;
unsigned long flags;
int wait = -1;
int plug_device = 0;
struct request *uninitialized_var(rq_in_flight);
spin_lock_irqsave(&hwif->lock, flags);
handler = hwif->handler;
if (handler == NULL || hwif->req_gen != hwif->req_gen_timer) {
/*
* Either a marginal timeout occurred
* (got the interrupt just as timer expired),
* or we were "sleeping" to give other devices a chance.
* Either way, we don't really want to complain about anything.
*/
} else {
ide_expiry_t *expiry = hwif->expiry;
ide_startstop_t startstop = ide_stopped;
drive = hwif->cur_dev;
if (expiry) {
wait = expiry(drive);
if (wait > 0) { /* continue */
/* reset timer */
hwif->timer.expires = jiffies + wait;
hwif->req_gen_timer = hwif->req_gen;
add_timer(&hwif->timer);
spin_unlock_irqrestore(&hwif->lock, flags);
return;
}
}
hwif->handler = NULL;
hwif->expiry = 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(&hwif->lock);
/* disable_irq_nosync ?? */
disable_irq(hwif->irq);
/* local CPU only, as if we were handling an interrupt */
local_irq_disable();
if (hwif->polling) {
startstop = handler(drive);
} else if (drive_is_ready(drive)) {
if (drive->waiting_for_dma)
hwif->dma_ops->dma_lost_irq(drive);
if (hwif->port_ops && hwif->port_ops->clear_irq)
hwif->port_ops->clear_irq(drive);
printk(KERN_WARNING "%s: lost interrupt\n",
drive->name);
startstop = handler(drive);
} else {
if (drive->waiting_for_dma)
startstop = ide_dma_timeout_retry(drive, wait);
else
startstop = ide_error(drive, "irq timeout",
hwif->tp_ops->read_status(hwif));
}
spin_lock_irq(&hwif->lock);
enable_irq(hwif->irq);
if (startstop == ide_stopped && hwif->polling == 0) {
rq_in_flight = hwif->rq;
hwif->rq = NULL;
ide_unlock_port(hwif);
plug_device = 1;
}
}
spin_unlock_irqrestore(&hwif->lock, flags);
if (plug_device) {
ide_unlock_host(hwif->host);
ide_requeue_and_plug(drive, rq_in_flight);
}
}
/**
* unexpected_intr - handle an unexpected IDE interrupt
* @irq: interrupt line
* @hwif: port 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.
*/
static void unexpected_intr(int irq, ide_hwif_t *hwif)
{
u8 stat = hwif->tp_ops->read_status(hwif);
if (!OK_STAT(stat, ATA_DRDY, BAD_STAT)) {
/* Try to not flood the console with msgs */
static unsigned long last_msgtime, count;
++count;
if (time_after(jiffies, last_msgtime + HZ)) {
last_msgtime = jiffies;
printk(KERN_ERR "%s: unexpected interrupt, "
"status=0x%02x, count=%ld\n",
hwif->name, stat, count);
}
}
}
/**
* ide_intr - default IDE interrupt handler
* @irq: interrupt number
* @dev_id: hwif
* @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
*
* hwif is the interface in the group currently performing
* a command. hwif->cur_dev is the drive and hwif->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 port and the process begins again.
*/
irqreturn_t ide_intr (int irq, void *dev_id)
{
ide_hwif_t *hwif = (ide_hwif_t *)dev_id;
struct ide_host *host = hwif->host;
ide_drive_t *uninitialized_var(drive);
ide_handler_t *handler;
unsigned long flags;
ide_startstop_t startstop;
irqreturn_t irq_ret = IRQ_NONE;
int plug_device = 0;
struct request *uninitialized_var(rq_in_flight);
if (host->host_flags & IDE_HFLAG_SERIALIZE) {
if (hwif != host->cur_port)
goto out_early;
}
spin_lock_irqsave(&hwif->lock, flags);
if (hwif->port_ops && hwif->port_ops->test_irq &&
hwif->port_ops->test_irq(hwif) == 0)
goto out;
handler = hwif->handler;
if (handler == NULL || hwif->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.
*/
if ((host->irq_flags & IRQF_SHARED) == 0) {
/*
* Probably not a shared PCI interrupt,
* so we can safely try to do something about it:
*/
unexpected_intr(irq, hwif);
} else {
/*
* Whack the status register, just in case
* we have a leftover pending IRQ.
*/
(void)hwif->tp_ops->read_status(hwif);
}
goto out;
}
drive = hwif->cur_dev;
if (!drive_is_ready(drive))
/*
* This happens regularly when we share a PCI IRQ with
* another device. Unfortunately, it can also happen
* with some buggy drives that trigger the IRQ before
* their status register is up to date. Hopefully we have
* enough advance overhead that the latter isn't a problem.
*/
goto out;
hwif->handler = NULL;
hwif->expiry = NULL;
hwif->req_gen++;
del_timer(&hwif->timer);
spin_unlock(&hwif->lock);
if (hwif->port_ops && hwif->port_ops->clear_irq)
hwif->port_ops->clear_irq(drive);
if (drive->dev_flags & IDE_DFLAG_UNMASK)
local_irq_enable_in_hardirq();
/* service this interrupt, may set handler for next interrupt */
startstop = handler(drive);
spin_lock_irq(&hwif->lock);
/*
* Note that handler() may have set things up for another
* interrupt to occur soon, but it cannot happen until
* we exit from this routine, because it will be the
* same irq as is currently being serviced here, and Linux
* won't allow another of the same (on any CPU) until we return.
*/
if (startstop == ide_stopped && hwif->polling == 0) {
BUG_ON(hwif->handler);
rq_in_flight = hwif->rq;
hwif->rq = NULL;
ide_unlock_port(hwif);
plug_device = 1;
}
irq_ret = IRQ_HANDLED;
out:
spin_unlock_irqrestore(&hwif->lock, flags);
out_early:
if (plug_device) {
ide_unlock_host(hwif->host);
ide_requeue_and_plug(drive, rq_in_flight);
}
return irq_ret;
}
EXPORT_SYMBOL_GPL(ide_intr);
void ide_pad_transfer(ide_drive_t *drive, int write, int len)
{
ide_hwif_t *hwif = drive->hwif;
u8 buf[4] = { 0 };
while (len > 0) {
if (write)
hwif->tp_ops->output_data(drive, NULL, buf, min(4, len));
else
hwif->tp_ops->input_data(drive, NULL, buf, min(4, len));
len -= 4;
}
}
EXPORT_SYMBOL_GPL(ide_pad_transfer);
