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![Jens Axboe](/assets/img/avatar_default.png)
Just because we are not requeuing a request does not mean that some aren't pending. So always issue a blk_delay_queue() if either we are requeueing OR there's pending IO. This fixes a boot problem for some IDE boxes. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
892 lines
24 KiB
C
892 lines
24 KiB
C
/*
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* IDE I/O functions
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*
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* Basic PIO and command management functionality.
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*
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* This code was split off from ide.c. See ide.c for history and original
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* copyrights.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2, or (at your option) any
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* later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* For the avoidance of doubt the "preferred form" of this code is one which
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* is in an open non patent encumbered format. Where cryptographic key signing
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* forms part of the process of creating an executable the information
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* including keys needed to generate an equivalently functional executable
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* are deemed to be part of the source code.
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*/
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/string.h>
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#include <linux/kernel.h>
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#include <linux/timer.h>
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#include <linux/mm.h>
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#include <linux/interrupt.h>
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#include <linux/major.h>
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#include <linux/errno.h>
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#include <linux/genhd.h>
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#include <linux/blkpg.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/pci.h>
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#include <linux/delay.h>
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#include <linux/ide.h>
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#include <linux/completion.h>
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#include <linux/reboot.h>
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#include <linux/cdrom.h>
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#include <linux/seq_file.h>
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#include <linux/device.h>
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#include <linux/kmod.h>
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#include <linux/scatterlist.h>
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#include <linux/bitops.h>
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#include <asm/byteorder.h>
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#include <asm/irq.h>
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#include <asm/uaccess.h>
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#include <asm/io.h>
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int ide_end_rq(ide_drive_t *drive, struct request *rq, int error,
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unsigned int nr_bytes)
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{
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/*
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* decide whether to reenable DMA -- 3 is a random magic for now,
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* if we DMA timeout more than 3 times, just stay in PIO
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*/
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if ((drive->dev_flags & IDE_DFLAG_DMA_PIO_RETRY) &&
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drive->retry_pio <= 3) {
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drive->dev_flags &= ~IDE_DFLAG_DMA_PIO_RETRY;
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ide_dma_on(drive);
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}
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return blk_end_request(rq, error, nr_bytes);
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}
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EXPORT_SYMBOL_GPL(ide_end_rq);
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void ide_complete_cmd(ide_drive_t *drive, struct ide_cmd *cmd, u8 stat, u8 err)
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{
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const struct ide_tp_ops *tp_ops = drive->hwif->tp_ops;
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struct ide_taskfile *tf = &cmd->tf;
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struct request *rq = cmd->rq;
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u8 tf_cmd = tf->command;
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tf->error = err;
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tf->status = stat;
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if (cmd->ftf_flags & IDE_FTFLAG_IN_DATA) {
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u8 data[2];
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tp_ops->input_data(drive, cmd, data, 2);
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cmd->tf.data = data[0];
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cmd->hob.data = data[1];
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}
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ide_tf_readback(drive, cmd);
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if ((cmd->tf_flags & IDE_TFLAG_CUSTOM_HANDLER) &&
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tf_cmd == ATA_CMD_IDLEIMMEDIATE) {
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if (tf->lbal != 0xc4) {
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printk(KERN_ERR "%s: head unload failed!\n",
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drive->name);
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ide_tf_dump(drive->name, cmd);
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} else
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drive->dev_flags |= IDE_DFLAG_PARKED;
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}
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if (rq && rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
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struct ide_cmd *orig_cmd = rq->special;
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if (cmd->tf_flags & IDE_TFLAG_DYN)
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kfree(orig_cmd);
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else
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memcpy(orig_cmd, cmd, sizeof(*cmd));
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}
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}
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int ide_complete_rq(ide_drive_t *drive, int error, unsigned int nr_bytes)
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{
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ide_hwif_t *hwif = drive->hwif;
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struct request *rq = hwif->rq;
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int rc;
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/*
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* if failfast is set on a request, override number of sectors
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* and complete the whole request right now
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*/
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if (blk_noretry_request(rq) && error <= 0)
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nr_bytes = blk_rq_sectors(rq) << 9;
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rc = ide_end_rq(drive, rq, error, nr_bytes);
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if (rc == 0)
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hwif->rq = NULL;
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return rc;
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}
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EXPORT_SYMBOL(ide_complete_rq);
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void ide_kill_rq(ide_drive_t *drive, struct request *rq)
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{
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u8 drv_req = (rq->cmd_type == REQ_TYPE_SPECIAL) && rq->rq_disk;
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u8 media = drive->media;
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drive->failed_pc = NULL;
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if ((media == ide_floppy || media == ide_tape) && drv_req) {
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rq->errors = 0;
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} else {
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if (media == ide_tape)
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rq->errors = IDE_DRV_ERROR_GENERAL;
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else if (rq->cmd_type != REQ_TYPE_FS && rq->errors == 0)
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rq->errors = -EIO;
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}
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ide_complete_rq(drive, -EIO, blk_rq_bytes(rq));
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}
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static void ide_tf_set_specify_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
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{
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tf->nsect = drive->sect;
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tf->lbal = drive->sect;
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tf->lbam = drive->cyl;
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tf->lbah = drive->cyl >> 8;
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tf->device = (drive->head - 1) | drive->select;
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tf->command = ATA_CMD_INIT_DEV_PARAMS;
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}
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static void ide_tf_set_restore_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
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{
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tf->nsect = drive->sect;
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tf->command = ATA_CMD_RESTORE;
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}
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static void ide_tf_set_setmult_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
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{
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tf->nsect = drive->mult_req;
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tf->command = ATA_CMD_SET_MULTI;
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}
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/**
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* do_special - issue some special commands
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* @drive: drive the command is for
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*
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* do_special() is used to issue ATA_CMD_INIT_DEV_PARAMS,
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* ATA_CMD_RESTORE and ATA_CMD_SET_MULTI commands to a drive.
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*/
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static ide_startstop_t do_special(ide_drive_t *drive)
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{
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struct ide_cmd cmd;
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#ifdef DEBUG
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printk(KERN_DEBUG "%s: %s: 0x%02x\n", drive->name, __func__,
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drive->special_flags);
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#endif
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if (drive->media != ide_disk) {
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drive->special_flags = 0;
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drive->mult_req = 0;
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return ide_stopped;
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}
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memset(&cmd, 0, sizeof(cmd));
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cmd.protocol = ATA_PROT_NODATA;
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if (drive->special_flags & IDE_SFLAG_SET_GEOMETRY) {
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drive->special_flags &= ~IDE_SFLAG_SET_GEOMETRY;
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ide_tf_set_specify_cmd(drive, &cmd.tf);
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} else if (drive->special_flags & IDE_SFLAG_RECALIBRATE) {
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drive->special_flags &= ~IDE_SFLAG_RECALIBRATE;
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ide_tf_set_restore_cmd(drive, &cmd.tf);
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} else if (drive->special_flags & IDE_SFLAG_SET_MULTMODE) {
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drive->special_flags &= ~IDE_SFLAG_SET_MULTMODE;
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ide_tf_set_setmult_cmd(drive, &cmd.tf);
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} else
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BUG();
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cmd.valid.out.tf = IDE_VALID_OUT_TF | IDE_VALID_DEVICE;
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cmd.valid.in.tf = IDE_VALID_IN_TF | IDE_VALID_DEVICE;
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cmd.tf_flags = IDE_TFLAG_CUSTOM_HANDLER;
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do_rw_taskfile(drive, &cmd);
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return ide_started;
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}
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void ide_map_sg(ide_drive_t *drive, struct ide_cmd *cmd)
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{
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ide_hwif_t *hwif = drive->hwif;
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struct scatterlist *sg = hwif->sg_table;
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struct request *rq = cmd->rq;
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cmd->sg_nents = blk_rq_map_sg(drive->queue, rq, sg);
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}
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EXPORT_SYMBOL_GPL(ide_map_sg);
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void ide_init_sg_cmd(struct ide_cmd *cmd, unsigned int nr_bytes)
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{
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cmd->nbytes = cmd->nleft = nr_bytes;
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cmd->cursg_ofs = 0;
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cmd->cursg = NULL;
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}
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EXPORT_SYMBOL_GPL(ide_init_sg_cmd);
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/**
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* execute_drive_command - issue special drive command
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* @drive: the drive to issue the command on
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* @rq: the request structure holding the command
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*
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* execute_drive_cmd() issues a special drive command, usually
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* initiated by ioctl() from the external hdparm program. The
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* command can be a drive command, drive task or taskfile
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* operation. Weirdly you can call it with NULL to wait for
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* all commands to finish. Don't do this as that is due to change
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*/
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static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
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struct request *rq)
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{
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struct ide_cmd *cmd = rq->special;
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if (cmd) {
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if (cmd->protocol == ATA_PROT_PIO) {
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ide_init_sg_cmd(cmd, blk_rq_sectors(rq) << 9);
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ide_map_sg(drive, cmd);
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}
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return do_rw_taskfile(drive, cmd);
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}
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/*
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* NULL is actually a valid way of waiting for
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* all current requests to be flushed from the queue.
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*/
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#ifdef DEBUG
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printk("%s: DRIVE_CMD (null)\n", drive->name);
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#endif
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rq->errors = 0;
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ide_complete_rq(drive, 0, blk_rq_bytes(rq));
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return ide_stopped;
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}
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static ide_startstop_t ide_special_rq(ide_drive_t *drive, struct request *rq)
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{
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u8 cmd = rq->cmd[0];
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switch (cmd) {
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case REQ_PARK_HEADS:
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case REQ_UNPARK_HEADS:
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return ide_do_park_unpark(drive, rq);
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case REQ_DEVSET_EXEC:
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return ide_do_devset(drive, rq);
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case REQ_DRIVE_RESET:
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return ide_do_reset(drive);
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default:
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BUG();
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}
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}
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/**
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* start_request - start of I/O and command issuing for IDE
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*
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* start_request() initiates handling of a new I/O request. It
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* accepts commands and I/O (read/write) requests.
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*
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* FIXME: this function needs a rename
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*/
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static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
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{
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ide_startstop_t startstop;
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BUG_ON(!(rq->cmd_flags & REQ_STARTED));
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#ifdef DEBUG
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printk("%s: start_request: current=0x%08lx\n",
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drive->hwif->name, (unsigned long) rq);
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#endif
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/* bail early if we've exceeded max_failures */
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if (drive->max_failures && (drive->failures > drive->max_failures)) {
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rq->cmd_flags |= REQ_FAILED;
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goto kill_rq;
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}
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if (blk_pm_request(rq))
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ide_check_pm_state(drive, rq);
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drive->hwif->tp_ops->dev_select(drive);
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if (ide_wait_stat(&startstop, drive, drive->ready_stat,
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ATA_BUSY | ATA_DRQ, WAIT_READY)) {
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printk(KERN_ERR "%s: drive not ready for command\n", drive->name);
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return startstop;
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}
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if (drive->special_flags == 0) {
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struct ide_driver *drv;
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/*
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* We reset the drive so we need to issue a SETFEATURES.
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* Do it _after_ do_special() restored device parameters.
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*/
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if (drive->current_speed == 0xff)
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ide_config_drive_speed(drive, drive->desired_speed);
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if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE)
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return execute_drive_cmd(drive, rq);
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else if (blk_pm_request(rq)) {
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struct request_pm_state *pm = rq->special;
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#ifdef DEBUG_PM
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printk("%s: start_power_step(step: %d)\n",
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drive->name, pm->pm_step);
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#endif
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startstop = ide_start_power_step(drive, rq);
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if (startstop == ide_stopped &&
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pm->pm_step == IDE_PM_COMPLETED)
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ide_complete_pm_rq(drive, rq);
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return startstop;
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} else if (!rq->rq_disk && rq->cmd_type == REQ_TYPE_SPECIAL)
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/*
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* TODO: Once all ULDs have been modified to
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* check for specific op codes rather than
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* blindly accepting any special request, the
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* check for ->rq_disk above may be replaced
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* by a more suitable mechanism or even
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* dropped entirely.
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*/
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return ide_special_rq(drive, rq);
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drv = *(struct ide_driver **)rq->rq_disk->private_data;
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return drv->do_request(drive, rq, blk_rq_pos(rq));
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}
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return do_special(drive);
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kill_rq:
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ide_kill_rq(drive, rq);
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return ide_stopped;
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}
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/**
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* ide_stall_queue - pause an IDE device
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* @drive: drive to stall
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* @timeout: time to stall for (jiffies)
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*
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* ide_stall_queue() can be used by a drive to give excess bandwidth back
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* to the port by sleeping for timeout jiffies.
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*/
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void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
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{
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if (timeout > WAIT_WORSTCASE)
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timeout = WAIT_WORSTCASE;
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drive->sleep = timeout + jiffies;
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drive->dev_flags |= IDE_DFLAG_SLEEPING;
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}
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EXPORT_SYMBOL(ide_stall_queue);
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static inline int ide_lock_port(ide_hwif_t *hwif)
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{
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if (hwif->busy)
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return 1;
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hwif->busy = 1;
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return 0;
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}
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static inline void ide_unlock_port(ide_hwif_t *hwif)
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{
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hwif->busy = 0;
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}
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static inline int ide_lock_host(struct ide_host *host, ide_hwif_t *hwif)
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{
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int rc = 0;
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if (host->host_flags & IDE_HFLAG_SERIALIZE) {
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rc = test_and_set_bit_lock(IDE_HOST_BUSY, &host->host_busy);
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if (rc == 0) {
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if (host->get_lock)
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host->get_lock(ide_intr, hwif);
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}
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}
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return rc;
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}
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static inline void ide_unlock_host(struct ide_host *host)
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{
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if (host->host_flags & IDE_HFLAG_SERIALIZE) {
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if (host->release_lock)
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host->release_lock();
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clear_bit_unlock(IDE_HOST_BUSY, &host->host_busy);
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}
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}
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static void __ide_requeue_and_plug(struct request_queue *q, struct request *rq)
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{
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if (rq)
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blk_requeue_request(q, rq);
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if (rq || blk_peek_request(q)) {
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/* Use 3ms as that was the old plug delay */
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blk_delay_queue(q, 3);
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}
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}
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void ide_requeue_and_plug(ide_drive_t *drive, struct request *rq)
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{
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struct request_queue *q = drive->queue;
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unsigned long flags;
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spin_lock_irqsave(q->queue_lock, flags);
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__ide_requeue_and_plug(q, rq);
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spin_unlock_irqrestore(q->queue_lock, flags);
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}
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/*
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* Issue a new request to a device.
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*/
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void do_ide_request(struct request_queue *q)
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{
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ide_drive_t *drive = q->queuedata;
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ide_hwif_t *hwif = drive->hwif;
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struct ide_host *host = hwif->host;
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struct request *rq = NULL;
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ide_startstop_t startstop;
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unsigned long queue_run_ms = 3; /* old plug delay */
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spin_unlock_irq(q->queue_lock);
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/* HLD do_request() callback might sleep, make sure it's okay */
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might_sleep();
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if (ide_lock_host(host, hwif))
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goto plug_device_2;
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spin_lock_irq(&hwif->lock);
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if (!ide_lock_port(hwif)) {
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ide_hwif_t *prev_port;
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WARN_ON_ONCE(hwif->rq);
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repeat:
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prev_port = hwif->host->cur_port;
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if (drive->dev_flags & IDE_DFLAG_SLEEPING &&
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time_after(drive->sleep, jiffies)) {
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unsigned long left = jiffies - drive->sleep;
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queue_run_ms = jiffies_to_msecs(left + 1);
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ide_unlock_port(hwif);
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goto plug_device;
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}
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if ((hwif->host->host_flags & IDE_HFLAG_SERIALIZE) &&
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hwif != prev_port) {
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ide_drive_t *cur_dev =
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prev_port ? prev_port->cur_dev : NULL;
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/*
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* set nIEN for previous port, drives in the
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* quirk list may not like intr setups/cleanups
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*/
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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);
|