ide-pm.c

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#include <linux/kernel.h>
#include <linux/gfp.h>
#include <linux/ide.h>

int generic_ide_suspend(struct device *dev, pm_message_t mesg)
{
    ide_drive_t *drive = to_ide_device(dev);
    ide_drive_t *pair = ide_get_pair_dev(drive);
    ide_hwif_t *hwif = drive->hwif;
    struct request *rq;
    struct request_pm_state rqpm;
    int ret;

    if (ide_port_acpi(hwif)) {
        /* call ACPI _GTM only once */
        if ((drive->dn & 1) == 0 || pair == NULL)
            ide_acpi_get_timing(hwif);
    }

    memset(&rqpm, 0, sizeof(rqpm));
    rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
    rq->cmd_type = REQ_TYPE_PM_SUSPEND;
    rq->special = &rqpm;
    rqpm.pm_step = IDE_PM_START_SUSPEND;
    if (mesg.event == PM_EVENT_PRETHAW)
        mesg.event = PM_EVENT_FREEZE;
    rqpm.pm_state = mesg.event;

    ret = blk_execute_rq(drive->queue, NULL, rq, 0);
    blk_put_request(rq);

    if (ret == 0 && ide_port_acpi(hwif)) {
        /* call ACPI _PS3 only after both devices are suspended */
        if ((drive->dn & 1) || pair == NULL)
            ide_acpi_set_state(hwif, 0);
    }

    return ret;
}

int generic_ide_resume(struct device *dev)
{
    ide_drive_t *drive = to_ide_device(dev);
    ide_drive_t *pair = ide_get_pair_dev(drive);
    ide_hwif_t *hwif = drive->hwif;
    struct request *rq;
    struct request_pm_state rqpm;
    int err;

    if (ide_port_acpi(hwif)) {
        /* call ACPI _PS0 / _STM only once */
        if ((drive->dn & 1) == 0 || pair == NULL) {
            ide_acpi_set_state(hwif, 1);
            ide_acpi_push_timing(hwif);
        }

        ide_acpi_exec_tfs(drive);
    }

    memset(&rqpm, 0, sizeof(rqpm));
    rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
    rq->cmd_type = REQ_TYPE_PM_RESUME;
    rq->cmd_flags |= REQ_PREEMPT;
    rq->special = &rqpm;
    rqpm.pm_step = IDE_PM_START_RESUME;
    rqpm.pm_state = PM_EVENT_ON;

    err = blk_execute_rq(drive->queue, NULL, rq, 1);
    blk_put_request(rq);

    if (err == 0 && dev->driver) {
        struct ide_driver *drv = to_ide_driver(dev->driver);

        if (drv->resume)
            drv->resume(drive);
    }

    return err;
}

void ide_complete_power_step(ide_drive_t *drive, struct request *rq)
{
    struct request_pm_state *pm = rq->special;

#ifdef DEBUG_PM
    printk(KERN_INFO "%s: complete_power_step(step: %d)\n",
        drive->name, pm->pm_step);
#endif
    if (drive->media != ide_disk)
        return;

    switch (pm->pm_step) {
    case IDE_PM_FLUSH_CACHE:    /* Suspend step 1 (flush cache) */
        if (pm->pm_state == PM_EVENT_FREEZE)
            pm->pm_step = IDE_PM_COMPLETED;
        else
            pm->pm_step = IDE_PM_STANDBY;
        break;
    case IDE_PM_STANDBY:        /* Suspend step 2 (standby) */
        pm->pm_step = IDE_PM_COMPLETED;
        break;
    case IDE_PM_RESTORE_PIO:    /* Resume step 1 (restore PIO) */
        pm->pm_step = IDE_PM_IDLE;
        break;
    case IDE_PM_IDLE:       /* Resume step 2 (idle)*/
        pm->pm_step = IDE_PM_RESTORE_DMA;
        break;
    }
}

ide_startstop_t ide_start_power_step(ide_drive_t *drive, struct request *rq)
{
    struct request_pm_state *pm = rq->special;
    struct ide_cmd cmd = { };

    switch (pm->pm_step) {
    case IDE_PM_FLUSH_CACHE:    /* Suspend step 1 (flush cache) */
        if (drive->media != ide_disk)
            break;
        /* Not supported? Switch to next step now. */
        if (ata_id_flush_enabled(drive->id) == 0 ||
            (drive->dev_flags & IDE_DFLAG_WCACHE) == 0) {
            ide_complete_power_step(drive, rq);
            return ide_stopped;
        }
        if (ata_id_flush_ext_enabled(drive->id))
            cmd.tf.command = ATA_CMD_FLUSH_EXT;
        else
            cmd.tf.command = ATA_CMD_FLUSH;
        goto out_do_tf;
    case IDE_PM_STANDBY:        /* Suspend step 2 (standby) */
        cmd.tf.command = ATA_CMD_STANDBYNOW1;
        goto out_do_tf;
    case IDE_PM_RESTORE_PIO:    /* Resume step 1 (restore PIO) */
        ide_set_max_pio(drive);
        /*
         * skip IDE_PM_IDLE for ATAPI devices
         */
        if (drive->media != ide_disk)
            pm->pm_step = IDE_PM_RESTORE_DMA;
        else
            ide_complete_power_step(drive, rq);
        return ide_stopped;
    case IDE_PM_IDLE:       /* Resume step 2 (idle) */
        cmd.tf.command = ATA_CMD_IDLEIMMEDIATE;
        goto out_do_tf;
    case IDE_PM_RESTORE_DMA:    /* Resume step 3 (restore DMA) */
        /*
         * Right now, all we do is call ide_set_dma(drive),
         * we could be smarter and check for current xfer_speed
         * in struct drive etc...
         */
        if (drive->hwif->dma_ops == NULL)
            break;
        /*
         * TODO: respect IDE_DFLAG_USING_DMA
         */
        ide_set_dma(drive);
        break;
    }

    pm->pm_step = IDE_PM_COMPLETED;

    return ide_stopped;

out_do_tf:
    cmd.valid.out.tf = IDE_VALID_OUT_TF | IDE_VALID_DEVICE;
    cmd.valid.in.tf  = IDE_VALID_IN_TF  | IDE_VALID_DEVICE;
    cmd.protocol = ATA_PROT_NODATA;

    return do_rw_taskfile(drive, &cmd);
}

void ide_complete_pm_rq(ide_drive_t *drive, struct request *rq)
{
    struct request_queue *q = drive->queue;
    struct request_pm_state *pm = rq->special;
    unsigned long flags;

    ide_complete_power_step(drive, rq);
    if (pm->pm_step != IDE_PM_COMPLETED)
        return;

#ifdef DEBUG_PM
    printk("%s: completing PM request, %s\n", drive->name,
           (rq->cmd_type == REQ_TYPE_PM_SUSPEND) ? "suspend" : "resume");
#endif
    spin_lock_irqsave(q->queue_lock, flags);
    if (rq->cmd_type == REQ_TYPE_PM_SUSPEND)
        blk_stop_queue(q);
    else
        drive->dev_flags &= ~IDE_DFLAG_BLOCKED;
    spin_unlock_irqrestore(q->queue_lock, flags);

    drive->hwif->rq = NULL;

    if (blk_end_request(rq, 0, 0))
        BUG();
}

void ide_check_pm_state(ide_drive_t *drive, struct request *rq)
{
    struct request_pm_state *pm = rq->special;

    if (rq->cmd_type == REQ_TYPE_PM_SUSPEND &&
        pm->pm_step == IDE_PM_START_SUSPEND)
        /* Mark drive blocked when starting the suspend sequence. */
        drive->dev_flags |= IDE_DFLAG_BLOCKED;
    else if (rq->cmd_type == REQ_TYPE_PM_RESUME &&
         pm->pm_step == IDE_PM_START_RESUME) {
        /*
         * The first thing we do on wakeup is to wait for BSY bit to
         * go away (with a looong timeout) as a drive on this hwif may
         * just be POSTing itself.
         * We do that before even selecting as the "other" device on
         * the bus may be broken enough to walk on our toes at this
         * point.
         */
        ide_hwif_t *hwif = drive->hwif;
        const struct ide_tp_ops *tp_ops = hwif->tp_ops;
        struct request_queue *q = drive->queue;
        unsigned long flags;
        int rc;
#ifdef DEBUG_PM
        printk("%s: Wakeup request inited, waiting for !BSY...\n", drive->name);
#endif
        rc = ide_wait_not_busy(hwif, 35000);
        if (rc)
            printk(KERN_WARNING "%s: bus not ready on wakeup\n", drive->name);
        tp_ops->dev_select(drive);
        tp_ops->write_devctl(hwif, ATA_DEVCTL_OBS);
        rc = ide_wait_not_busy(hwif, 100000);
        if (rc)
            printk(KERN_WARNING "%s: drive not ready on wakeup\n", drive->name);

        spin_lock_irqsave(q->queue_lock, flags);
        blk_start_queue(q);
        spin_unlock_irqrestore(q->queue_lock, flags);
    }
}