diff options
Diffstat (limited to 'drivers/ide/ide-io.c')
| -rw-r--r-- | drivers/ide/ide-io.c | 904 |
1 files changed, 0 insertions, 904 deletions
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c deleted file mode 100644 index 4867b67b60d6..000000000000 --- a/drivers/ide/ide-io.c +++ /dev/null @@ -1,904 +0,0 @@ -/* - * 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 <linux/uaccess.h> -#include <asm/io.h> - -int ide_end_rq(ide_drive_t *drive, struct request *rq, blk_status_t 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); - } - - if (!blk_update_request(rq, error, nr_bytes)) { - if (rq == drive->sense_rq) { - drive->sense_rq = NULL; - drive->sense_rq_active = false; - } - - __blk_mq_end_request(rq, error); - return 0; - } - - return 1; -} -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 && ata_taskfile_request(rq)) { - struct ide_cmd *orig_cmd = ide_req(rq)->special; - - if (cmd->tf_flags & IDE_TFLAG_DYN) - kfree(orig_cmd); - else if (cmd != orig_cmd) - memcpy(orig_cmd, cmd, sizeof(*cmd)); - } -} - -int ide_complete_rq(ide_drive_t *drive, blk_status_t 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) - 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 = ata_misc_request(rq) && rq->rq_disk; - u8 media = drive->media; - - drive->failed_pc = NULL; - - if ((media == ide_floppy || media == ide_tape) && drv_req) { - scsi_req(rq)->result = 0; - } else { - if (media == ide_tape) - scsi_req(rq)->result = IDE_DRV_ERROR_GENERAL; - else if (blk_rq_is_passthrough(rq) && scsi_req(rq)->result == 0) - scsi_req(rq)->result = -EIO; - } - - ide_complete_rq(drive, BLK_STS_IOERR, 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, *last_sg = NULL; - struct request *rq = cmd->rq; - - cmd->sg_nents = __blk_rq_map_sg(drive->queue, rq, sg, &last_sg); - if (blk_rq_bytes(rq) && (blk_rq_bytes(rq) & rq->q->dma_pad_mask)) - last_sg->length += - (rq->q->dma_pad_mask & ~blk_rq_bytes(rq)) + 1; -} -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 = ide_req(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 - scsi_req(rq)->result = 0; - ide_complete_rq(drive, BLK_STS_OK, blk_rq_bytes(rq)); - - return ide_stopped; -} - -static ide_startstop_t ide_special_rq(ide_drive_t *drive, struct request *rq) -{ - u8 cmd = scsi_req(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; - -#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->rq_flags |= RQF_FAILED; - goto kill_rq; - } - - if (drive->prep_rq && !drive->prep_rq(drive, rq)) - return ide_stopped; - - if (ata_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 (ata_taskfile_request(rq)) - return execute_drive_cmd(drive, rq); - else if (ata_pm_request(rq)) { - struct ide_pm_state *pm = ide_req(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 && ata_misc_request(rq)) - /* - * TODO: Once all ULDs have been modified to - * check for specific op codes rather than - * blindly accepting any special request, the - * check for ->rq_disk above may be replaced - * by a more suitable mechanism or even - * dropped entirely. - */ - return ide_special_rq(drive, rq); - - drv = *(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); - } -} - -void ide_requeue_and_plug(ide_drive_t *drive, struct request *rq) -{ - struct request_queue *q = drive->queue; - - /* Use 3ms as that was the old plug delay */ - if (rq) { - blk_mq_requeue_request(rq, false); - blk_mq_delay_kick_requeue_list(q, 3); - } else - blk_mq_delay_run_hw_queue(q->queue_hw_ctx[0], 3); -} - -blk_status_t ide_issue_rq(ide_drive_t *drive, struct request *rq, - bool local_requeue) -{ - ide_hwif_t *hwif = drive->hwif; - struct ide_host *host = hwif->host; - ide_startstop_t startstop; - - if (!blk_rq_is_passthrough(rq) && !(rq->rq_flags & RQF_DONTPREP)) { - rq->rq_flags |= RQF_DONTPREP; - ide_req(rq)->special = NULL; - } - - /* HLD do_request() callback might sleep, make sure it's okay */ - might_sleep(); - - if (ide_lock_host(host, hwif)) - return BLK_STS_DEV_RESOURCE; - - 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)) { - 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); - - /* - * 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... - */ - if ((drive->dev_flags & IDE_DFLAG_BLOCKED) && - ata_pm_request(rq) == 0 && - (rq->rq_flags & RQF_PM) == 0) { - /* there should be no pending command at this point */ - ide_unlock_port(hwif); - goto plug_device; - } - - scsi_req(rq)->resid_len = blk_rq_bytes(rq); - 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; - if (rq) - goto repeat; - ide_unlock_port(hwif); - goto out; - } - } else { -plug_device: - if (local_requeue) - list_add(&rq->queuelist, &drive->rq_list); - spin_unlock_irq(&hwif->lock); - ide_unlock_host(host); - if (!local_requeue) - ide_requeue_and_plug(drive, rq); - return BLK_STS_OK; - } - -out: - spin_unlock_irq(&hwif->lock); - if (rq == NULL) - ide_unlock_host(host); - return BLK_STS_OK; -} - -/* - * Issue a new request to a device. - */ -blk_status_t ide_queue_rq(struct blk_mq_hw_ctx *hctx, - const struct blk_mq_queue_data *bd) -{ - ide_drive_t *drive = hctx->queue->queuedata; - ide_hwif_t *hwif = drive->hwif; - - spin_lock_irq(&hwif->lock); - if (drive->sense_rq_active) { - spin_unlock_irq(&hwif->lock); - return BLK_STS_DEV_RESOURCE; - } - spin_unlock_irq(&hwif->lock); - - blk_mq_start_request(bd->rq); - return ide_issue_rq(drive, bd->rq, false); -} - -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 (struct timer_list *t) -{ - ide_hwif_t *hwif = from_timer(hwif, t, timer); - ide_drive_t *drive; - ide_handler_t *handler; - unsigned long flags; - int wait = -1; - int plug_device = 0; - struct request *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); - - 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)); - } - /* Disable interrupts again, `handler' might have enabled it */ - 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 *drive; - ide_handler_t *handler; - unsigned long flags; - ide_startstop_t startstop; - irqreturn_t irq_ret = IRQ_NONE; - int plug_device = 0; - struct request *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); - -void ide_insert_request_head(ide_drive_t *drive, struct request *rq) -{ - drive->sense_rq_active = true; - list_add_tail(&rq->queuelist, &drive->rq_list); - kblockd_schedule_work(&drive->rq_work); -} -EXPORT_SYMBOL_GPL(ide_insert_request_head); |