ide-atapi.c

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/*
 * ATAPI support.
 */

#include <linux/kernel.h>
#include <linux/cdrom.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <linux/ide.h>
#include <linux/scatterlist.h>
#include <linux/gfp.h>

#include <scsi/scsi.h>

#define DRV_NAME "ide-atapi"
#define PFX DRV_NAME ": "

#ifdef DEBUG
#define debug_log(fmt, args...) \
    printk(KERN_INFO "ide: " fmt, ## args)
#else
#define debug_log(fmt, args...) do {} while (0)
#endif

#define ATAPI_MIN_CDB_BYTES 12

static inline int dev_is_idecd(ide_drive_t *drive)
{
    return drive->media == ide_cdrom || drive->media == ide_optical;
}

/*
 * Check whether we can support a device,
 * based on the ATAPI IDENTIFY command results.
 */
int ide_check_atapi_device(ide_drive_t *drive, const char *s)
{
    u16 *id = drive->id;
    u8 gcw[2], protocol, device_type, removable, drq_type, packet_size;

    *((u16 *)&gcw) = id[ATA_ID_CONFIG];

    protocol    = (gcw[1] & 0xC0) >> 6;
    device_type =  gcw[1] & 0x1F;
    removable   = (gcw[0] & 0x80) >> 7;
    drq_type    = (gcw[0] & 0x60) >> 5;
    packet_size =  gcw[0] & 0x03;

#ifdef CONFIG_PPC
    /* kludge for Apple PowerBook internal zip */
    if (drive->media == ide_floppy && device_type == 5 &&
        !strstr((char *)&id[ATA_ID_PROD], "CD-ROM") &&
        strstr((char *)&id[ATA_ID_PROD], "ZIP"))
        device_type = 0;
#endif

    if (protocol != 2)
        printk(KERN_ERR "%s: %s: protocol (0x%02x) is not ATAPI\n",
            s, drive->name, protocol);
    else if ((drive->media == ide_floppy && device_type != 0) ||
         (drive->media == ide_tape && device_type != 1))
        printk(KERN_ERR "%s: %s: invalid device type (0x%02x)\n",
            s, drive->name, device_type);
    else if (removable == 0)
        printk(KERN_ERR "%s: %s: the removable flag is not set\n",
            s, drive->name);
    else if (drive->media == ide_floppy && drq_type == 3)
        printk(KERN_ERR "%s: %s: sorry, DRQ type (0x%02x) not "
            "supported\n", s, drive->name, drq_type);
    else if (packet_size != 0)
        printk(KERN_ERR "%s: %s: packet size (0x%02x) is not 12 "
            "bytes\n", s, drive->name, packet_size);
    else
        return 1;
    return 0;
}
EXPORT_SYMBOL_GPL(ide_check_atapi_device);

void ide_init_pc(struct ide_atapi_pc *pc)
{
    memset(pc, 0, sizeof(*pc));
}
EXPORT_SYMBOL_GPL(ide_init_pc);

/*
 * Add a special packet command request to the tail of the request queue,
 * and wait for it to be serviced.
 */
int ide_queue_pc_tail(ide_drive_t *drive, struct gendisk *disk,
              struct ide_atapi_pc *pc, void *buf, unsigned int bufflen)
{
    struct request *rq;
    int error;

    rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
    rq->cmd_type = REQ_TYPE_SPECIAL;
    rq->special = (char *)pc;

    if (buf && bufflen) {
        error = blk_rq_map_kern(drive->queue, rq, buf, bufflen,
                    GFP_NOIO);
        if (error)
            goto put_req;
    }

    memcpy(rq->cmd, pc->c, 12);
    if (drive->media == ide_tape)
        rq->cmd[13] = REQ_IDETAPE_PC1;
    error = blk_execute_rq(drive->queue, disk, rq, 0);
put_req:
    blk_put_request(rq);
    return error;
}
EXPORT_SYMBOL_GPL(ide_queue_pc_tail);

int ide_do_test_unit_ready(ide_drive_t *drive, struct gendisk *disk)
{
    struct ide_atapi_pc pc;

    ide_init_pc(&pc);
    pc.c[0] = TEST_UNIT_READY;

    return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
}
EXPORT_SYMBOL_GPL(ide_do_test_unit_ready);

int ide_do_start_stop(ide_drive_t *drive, struct gendisk *disk, int start)
{
    struct ide_atapi_pc pc;

    ide_init_pc(&pc);
    pc.c[0] = START_STOP;
    pc.c[4] = start;

    if (drive->media == ide_tape)
        pc.flags |= PC_FLAG_WAIT_FOR_DSC;

    return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
}
EXPORT_SYMBOL_GPL(ide_do_start_stop);

int ide_set_media_lock(ide_drive_t *drive, struct gendisk *disk, int on)
{
    struct ide_atapi_pc pc;

    if ((drive->dev_flags & IDE_DFLAG_DOORLOCKING) == 0)
        return 0;

    ide_init_pc(&pc);
    pc.c[0] = ALLOW_MEDIUM_REMOVAL;
    pc.c[4] = on;

    return ide_queue_pc_tail(drive, disk, &pc, NULL, 0);
}
EXPORT_SYMBOL_GPL(ide_set_media_lock);

void ide_create_request_sense_cmd(ide_drive_t *drive, struct ide_atapi_pc *pc)
{
    ide_init_pc(pc);
    pc->c[0] = REQUEST_SENSE;
    if (drive->media == ide_floppy) {
        pc->c[4] = 255;
        pc->req_xfer = 18;
    } else {
        pc->c[4] = 20;
        pc->req_xfer = 20;
    }
}
EXPORT_SYMBOL_GPL(ide_create_request_sense_cmd);

void ide_prep_sense(ide_drive_t *drive, struct request *rq)
{
    struct request_sense *sense = &drive->sense_data;
    struct request *sense_rq = &drive->sense_rq;
    unsigned int cmd_len, sense_len;
    int err;

    switch (drive->media) {
    case ide_floppy:
        cmd_len = 255;
        sense_len = 18;
        break;
    case ide_tape:
        cmd_len = 20;
        sense_len = 20;
        break;
    default:
        cmd_len = 18;
        sense_len = 18;
    }

    BUG_ON(sense_len > sizeof(*sense));

    if (rq->cmd_type == REQ_TYPE_SENSE || drive->sense_rq_armed)
        return;

    memset(sense, 0, sizeof(*sense));

    blk_rq_init(rq->q, sense_rq);

    err = blk_rq_map_kern(drive->queue, sense_rq, sense, sense_len,
                  GFP_NOIO);
    if (unlikely(err)) {
        if (printk_ratelimit())
            printk(KERN_WARNING PFX "%s: failed to map sense "
                        "buffer\n", drive->name);
        return;
    }

    sense_rq->rq_disk = rq->rq_disk;
    sense_rq->cmd[0] = GPCMD_REQUEST_SENSE;
    sense_rq->cmd[4] = cmd_len;
    sense_rq->cmd_type = REQ_TYPE_SENSE;
    sense_rq->cmd_flags |= REQ_PREEMPT;

    if (drive->media == ide_tape)
        sense_rq->cmd[13] = REQ_IDETAPE_PC1;

    drive->sense_rq_armed = true;
}
EXPORT_SYMBOL_GPL(ide_prep_sense);

int ide_queue_sense_rq(ide_drive_t *drive, void *special)
{
    /* deferred failure from ide_prep_sense() */
    if (!drive->sense_rq_armed) {
        printk(KERN_WARNING PFX "%s: error queuing a sense request\n",
               drive->name);
        return -ENOMEM;
    }

    drive->sense_rq.special = special;
    drive->sense_rq_armed = false;

    drive->hwif->rq = NULL;

    elv_add_request(drive->queue, &drive->sense_rq, ELEVATOR_INSERT_FRONT);
    return 0;
}
EXPORT_SYMBOL_GPL(ide_queue_sense_rq);

/*
 * Called when an error was detected during the last packet command.
 * We queue a request sense packet command at the head of the request
 * queue.
 */
void ide_retry_pc(ide_drive_t *drive)
{
    struct request *failed_rq = drive->hwif->rq;
    struct request *sense_rq = &drive->sense_rq;
    struct ide_atapi_pc *pc = &drive->request_sense_pc;

    (void)ide_read_error(drive);

    /* init pc from sense_rq */
    ide_init_pc(pc);
    memcpy(pc->c, sense_rq->cmd, 12);

    if (drive->media == ide_tape)
        drive->atapi_flags |= IDE_AFLAG_IGNORE_DSC;

    /*
     * Push back the failed request and put request sense on top
     * of it.  The failed command will be retried after sense data
     * is acquired.
     */
    drive->hwif->rq = NULL;
    ide_requeue_and_plug(drive, failed_rq);
    if (ide_queue_sense_rq(drive, pc)) {
        blk_start_request(failed_rq);
        ide_complete_rq(drive, -EIO, blk_rq_bytes(failed_rq));
    }
}
EXPORT_SYMBOL_GPL(ide_retry_pc);

int ide_cd_expiry(ide_drive_t *drive)
{
    struct request *rq = drive->hwif->rq;
    unsigned long wait = 0;

    debug_log("%s: rq->cmd[0]: 0x%x\n", __func__, rq->cmd[0]);

    /*
     * Some commands are *slow* and normally take a long time to complete.
     * Usually we can use the ATAPI "disconnect" to bypass this, but not all
     * commands/drives support that. Let ide_timer_expiry keep polling us
     * for these.
     */
    switch (rq->cmd[0]) {
    case GPCMD_BLANK:
    case GPCMD_FORMAT_UNIT:
    case GPCMD_RESERVE_RZONE_TRACK:
    case GPCMD_CLOSE_TRACK:
    case GPCMD_FLUSH_CACHE:
        wait = ATAPI_WAIT_PC;
        break;
    default:
        if (!(rq->cmd_flags & REQ_QUIET))
            printk(KERN_INFO PFX "cmd 0x%x timed out\n",
                     rq->cmd[0]);
        wait = 0;
        break;
    }
    return wait;
}
EXPORT_SYMBOL_GPL(ide_cd_expiry);

int ide_cd_get_xferlen(struct request *rq)
{
    switch (rq->cmd_type) {
    case REQ_TYPE_FS:
        return 32768;
    case REQ_TYPE_SENSE:
    case REQ_TYPE_BLOCK_PC:
    case REQ_TYPE_ATA_PC:
        return blk_rq_bytes(rq);
    default:
        return 0;
    }
}
EXPORT_SYMBOL_GPL(ide_cd_get_xferlen);

void ide_read_bcount_and_ireason(ide_drive_t *drive, u16 *bcount, u8 *ireason)
{
    struct ide_taskfile tf;

    drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT |
                     IDE_VALID_LBAM | IDE_VALID_LBAH);

    *bcount = (tf.lbah << 8) | tf.lbam;
    *ireason = tf.nsect & 3;
}
EXPORT_SYMBOL_GPL(ide_read_bcount_and_ireason);

/*
 * Check the contents of the interrupt reason register and attempt to recover if
 * there are problems.
 *
 * Returns:
 * - 0 if everything's ok
 * - 1 if the request has to be terminated.
 */
int ide_check_ireason(ide_drive_t *drive, struct request *rq, int len,
              int ireason, int rw)
{
    ide_hwif_t *hwif = drive->hwif;

    debug_log("ireason: 0x%x, rw: 0x%x\n", ireason, rw);

    if (ireason == (!rw << 1))
        return 0;
    else if (ireason == (rw << 1)) {
        printk(KERN_ERR PFX "%s: %s: wrong transfer direction!\n",
                drive->name, __func__);

        if (dev_is_idecd(drive))
            ide_pad_transfer(drive, rw, len);
    } else if (!rw && ireason == ATAPI_COD) {
        if (dev_is_idecd(drive)) {
            /*
             * Some drives (ASUS) seem to tell us that status info
             * is available.  Just get it and ignore.
             */
            (void)hwif->tp_ops->read_status(hwif);
            return 0;
        }
    } else {
        if (ireason & ATAPI_COD)
            printk(KERN_ERR PFX "%s: CoD != 0 in %s\n", drive->name,
                    __func__);

        /* drive wants a command packet, or invalid ireason... */
        printk(KERN_ERR PFX "%s: %s: bad interrupt reason 0x%02x\n",
                drive->name, __func__, ireason);
    }

    if (dev_is_idecd(drive) && rq->cmd_type == REQ_TYPE_ATA_PC)
        rq->cmd_flags |= REQ_FAILED;

    return 1;
}
EXPORT_SYMBOL_GPL(ide_check_ireason);

/*
 * This is the usual interrupt handler which will be called during a packet
 * command.  We will transfer some of the data (as requested by the drive)
 * and will re-point interrupt handler to us.
 */
static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
{
    struct ide_atapi_pc *pc = drive->pc;
    ide_hwif_t *hwif = drive->hwif;
    struct ide_cmd *cmd = &hwif->cmd;
    struct request *rq = hwif->rq;
    const struct ide_tp_ops *tp_ops = hwif->tp_ops;
    unsigned int timeout, done;
    u16 bcount;
    u8 stat, ireason, dsc = 0;
    u8 write = !!(pc->flags & PC_FLAG_WRITING);

    debug_log("Enter %s - interrupt handler\n", __func__);

    timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
                           : WAIT_TAPE_CMD;

    /* Clear the interrupt */
    stat = tp_ops->read_status(hwif);

    if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
        int rc;

        drive->waiting_for_dma = 0;
        rc = hwif->dma_ops->dma_end(drive);
        ide_dma_unmap_sg(drive, cmd);

        if (rc || (drive->media == ide_tape && (stat & ATA_ERR))) {
            if (drive->media == ide_floppy)
                printk(KERN_ERR PFX "%s: DMA %s error\n",
                    drive->name, rq_data_dir(pc->rq)
                             ? "write" : "read");
            pc->flags |= PC_FLAG_DMA_ERROR;
        } else
            rq->resid_len = 0;
        debug_log("%s: DMA finished\n", drive->name);
    }

    /* No more interrupts */
    if ((stat & ATA_DRQ) == 0) {
        int uptodate, error;

        debug_log("Packet command completed, %d bytes transferred\n",
              blk_rq_bytes(rq));

        pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;

        local_irq_enable_in_hardirq();

        if (drive->media == ide_tape &&
            (stat & ATA_ERR) && rq->cmd[0] == REQUEST_SENSE)
            stat &= ~ATA_ERR;

        if ((stat & ATA_ERR) || (pc->flags & PC_FLAG_DMA_ERROR)) {
            /* Error detected */
            debug_log("%s: I/O error\n", drive->name);

            if (drive->media != ide_tape)
                pc->rq->errors++;

            if (rq->cmd[0] == REQUEST_SENSE) {
                printk(KERN_ERR PFX "%s: I/O error in request "
                        "sense command\n", drive->name);
                return ide_do_reset(drive);
            }

            debug_log("[cmd %x]: check condition\n", rq->cmd[0]);

            /* Retry operation */
            ide_retry_pc(drive);

            /* queued, but not started */
            return ide_stopped;
        }
        pc->error = 0;

        if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) && (stat & ATA_DSC) == 0)
            dsc = 1;

        /*
         * ->pc_callback() might change rq->data_len for
         * residual count, cache total length.
         */
        done = blk_rq_bytes(rq);

        /* Command finished - Call the callback function */
        uptodate = drive->pc_callback(drive, dsc);

        if (uptodate == 0)
            drive->failed_pc = NULL;

        if (rq->cmd_type == REQ_TYPE_SPECIAL) {
            rq->errors = 0;
            error = 0;
        } else {

            if (rq->cmd_type != REQ_TYPE_FS && uptodate <= 0) {
                if (rq->errors == 0)
                    rq->errors = -EIO;
            }

            error = uptodate ? 0 : -EIO;
        }

        ide_complete_rq(drive, error, blk_rq_bytes(rq));
        return ide_stopped;
    }

    if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
        pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
        printk(KERN_ERR PFX "%s: The device wants to issue more "
                "interrupts in DMA mode\n", drive->name);
        ide_dma_off(drive);
        return ide_do_reset(drive);
    }

    /* Get the number of bytes to transfer on this interrupt. */
    ide_read_bcount_and_ireason(drive, &bcount, &ireason);

    if (ide_check_ireason(drive, rq, bcount, ireason, write))
        return ide_do_reset(drive);

    done = min_t(unsigned int, bcount, cmd->nleft);
    ide_pio_bytes(drive, cmd, write, done);

    /* Update transferred byte count */
    rq->resid_len -= done;

    bcount -= done;

    if (bcount)
        ide_pad_transfer(drive, write, bcount);

    debug_log("[cmd %x] transferred %d bytes, padded %d bytes, resid: %u\n",
          rq->cmd[0], done, bcount, rq->resid_len);

    /* And set the interrupt handler again */
    ide_set_handler(drive, ide_pc_intr, timeout);
    return ide_started;
}

static void ide_init_packet_cmd(struct ide_cmd *cmd, u8 valid_tf,
                u16 bcount, u8 dma)
{
    cmd->protocol = dma ? ATAPI_PROT_DMA : ATAPI_PROT_PIO;
    cmd->valid.out.tf = IDE_VALID_LBAH | IDE_VALID_LBAM |
                IDE_VALID_FEATURE | valid_tf;
    cmd->tf.command = ATA_CMD_PACKET;
    cmd->tf.feature = dma;      /* Use PIO/DMA */
    cmd->tf.lbam    = bcount & 0xff;
    cmd->tf.lbah    = (bcount >> 8) & 0xff;
}

static u8 ide_read_ireason(ide_drive_t *drive)
{
    struct ide_taskfile tf;

    drive->hwif->tp_ops->tf_read(drive, &tf, IDE_VALID_NSECT);

    return tf.nsect & 3;
}

static u8 ide_wait_ireason(ide_drive_t *drive, u8 ireason)
{
    int retries = 100;

    while (retries-- && ((ireason & ATAPI_COD) == 0 ||
        (ireason & ATAPI_IO))) {
        printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing "
                "a packet command, retrying\n", drive->name);
        udelay(100);
        ireason = ide_read_ireason(drive);
        if (retries == 0) {
            printk(KERN_ERR PFX "%s: (IO,CoD != (0,1) while issuing"
                    " a packet command, ignoring\n",
                    drive->name);
            ireason |= ATAPI_COD;
            ireason &= ~ATAPI_IO;
        }
    }

    return ireason;
}

static int ide_delayed_transfer_pc(ide_drive_t *drive)
{
    /* Send the actual packet */
    drive->hwif->tp_ops->output_data(drive, NULL, drive->pc->c, 12);

    /* Timeout for the packet command */
    return WAIT_FLOPPY_CMD;
}

static ide_startstop_t ide_transfer_pc(ide_drive_t *drive)
{
    struct ide_atapi_pc *uninitialized_var(pc);
    ide_hwif_t *hwif = drive->hwif;
    struct request *rq = hwif->rq;
    ide_expiry_t *expiry;
    unsigned int timeout;
    int cmd_len;
    ide_startstop_t startstop;
    u8 ireason;

    if (ide_wait_stat(&startstop, drive, ATA_DRQ, ATA_BUSY, WAIT_READY)) {
        printk(KERN_ERR PFX "%s: Strange, packet command initiated yet "
                "DRQ isn't asserted\n", drive->name);
        return startstop;
    }

    if (drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT) {
        if (drive->dma)
            drive->waiting_for_dma = 1;
    }

    if (dev_is_idecd(drive)) {
        /* ATAPI commands get padded out to 12 bytes minimum */
        cmd_len = COMMAND_SIZE(rq->cmd[0]);
        if (cmd_len < ATAPI_MIN_CDB_BYTES)
            cmd_len = ATAPI_MIN_CDB_BYTES;

        timeout = rq->timeout;
        expiry  = ide_cd_expiry;
    } else {
        pc = drive->pc;

        cmd_len = ATAPI_MIN_CDB_BYTES;

        /*
         * If necessary schedule the packet transfer to occur 'timeout'
         * milliseconds later in ide_delayed_transfer_pc() after the
         * device says it's ready for a packet.
         */
        if (drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) {
            timeout = drive->pc_delay;
            expiry = &ide_delayed_transfer_pc;
        } else {
            timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
                                   : WAIT_TAPE_CMD;
            expiry = NULL;
        }

        ireason = ide_read_ireason(drive);
        if (drive->media == ide_tape)
            ireason = ide_wait_ireason(drive, ireason);

        if ((ireason & ATAPI_COD) == 0 || (ireason & ATAPI_IO)) {
            printk(KERN_ERR PFX "%s: (IO,CoD) != (0,1) while "
                "issuing a packet command\n", drive->name);

            return ide_do_reset(drive);
        }
    }

    hwif->expiry = expiry;

    /* Set the interrupt routine */
    ide_set_handler(drive,
            (dev_is_idecd(drive) ? drive->irq_handler
                         : ide_pc_intr),
            timeout);

    /* Send the actual packet */
    if ((drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) == 0)
        hwif->tp_ops->output_data(drive, NULL, rq->cmd, cmd_len);

    /* Begin DMA, if necessary */
    if (dev_is_idecd(drive)) {
        if (drive->dma)
            hwif->dma_ops->dma_start(drive);
    } else {
        if (pc->flags & PC_FLAG_DMA_OK) {
            pc->flags |= PC_FLAG_DMA_IN_PROGRESS;
            hwif->dma_ops->dma_start(drive);
        }
    }

    return ide_started;
}

ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_cmd *cmd)
{
    struct ide_atapi_pc *pc;
    ide_hwif_t *hwif = drive->hwif;
    ide_expiry_t *expiry = NULL;
    struct request *rq = hwif->rq;
    unsigned int timeout, bytes;
    u16 bcount;
    u8 valid_tf;
    u8 drq_int = !!(drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT);

    if (dev_is_idecd(drive)) {
        valid_tf = IDE_VALID_NSECT | IDE_VALID_LBAL;
        bcount = ide_cd_get_xferlen(rq);
        expiry = ide_cd_expiry;
        timeout = ATAPI_WAIT_PC;

        if (drive->dma)
            drive->dma = !ide_dma_prepare(drive, cmd);
    } else {
        pc = drive->pc;

        valid_tf = IDE_VALID_DEVICE;
        bytes = blk_rq_bytes(rq);
        bcount = ((drive->media == ide_tape) ? bytes
                             : min_t(unsigned int,
                                 bytes, 63 * 1024));

        /* We haven't transferred any data yet */
        rq->resid_len = bcount;

        if (pc->flags & PC_FLAG_DMA_ERROR) {
            pc->flags &= ~PC_FLAG_DMA_ERROR;
            ide_dma_off(drive);
        }

        if (pc->flags & PC_FLAG_DMA_OK)
            drive->dma = !ide_dma_prepare(drive, cmd);

        if (!drive->dma)
            pc->flags &= ~PC_FLAG_DMA_OK;

        timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
                               : WAIT_TAPE_CMD;
    }

    ide_init_packet_cmd(cmd, valid_tf, bcount, drive->dma);

    (void)do_rw_taskfile(drive, cmd);

    if (drq_int) {
        if (drive->dma)
            drive->waiting_for_dma = 0;
        hwif->expiry = expiry;
    }

    ide_execute_command(drive, cmd, ide_transfer_pc, timeout);

    return drq_int ? ide_started : ide_transfer_pc(drive);
}
EXPORT_SYMBOL_GPL(ide_issue_pc);