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libata: implement drain buffers

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This just updates the libata slave configure routine to take advantage
of the block layer drain buffers.  It also adjusts the size lengths in
the atapi code to add the drain buffer to the DMA length so the driver
knows it can rely on it.

I suspect I should also be checking for AHCI as well as ATA_DEV_ATAPI,
but I couldn't see how to do that easily.

tj: * atapi_drain_needed() added such that draining is applied to only
      misc ATAPI commands.
    * q->bounce_gfp used when allocating drain buffer.
    * Now duplicate ATAPI PIO drain logic dropped.
    * ata_dev_printk() used instead of sdev_printk().

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
James Bottomley 2008-02-19 11:36:57 +01:00 • committed by Jens Axboe
parent dde2020754
commit fa2fc7f481
2 changed files with 57 additions and 58 deletions
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59
drivers/ata/libata-scsi.c
View file

@ -826,17 +826,56 @@ static void ata_scsi_sdev_config(struct scsi_device *sdev)
sdev->max_device_blocked = 1;
}
static void ata_scsi_dev_config(struct scsi_device *sdev,
struct ata_device *dev)
/**
* atapi_drain_needed - Check whether data transfer may overflow
* @request: request to be checked
*
* ATAPI commands which transfer variable length data to host
* might overflow due to application error or hardare bug. This
* function checks whether overflow should be drained and ignored
* for @request.
*
* LOCKING:
* None.
*
* RETURNS:
* 1 if ; otherwise, 0.
*/
static int atapi_drain_needed(struct request *rq)
{
if (likely(!blk_pc_request(rq)))
return 0;
if (!rq->data_len || (rq->cmd_flags & REQ_RW))
return 0;
return atapi_cmd_type(rq->cmd[0]) == ATAPI_MISC;
}
static int ata_scsi_dev_config(struct scsi_device *sdev,
struct ata_device *dev)
{
/* configure max sectors */
blk_queue_max_sectors(sdev->request_queue, dev->max_sectors);
if (dev->class == ATA_DEV_ATAPI)
if (dev->class == ATA_DEV_ATAPI) {
struct request_queue *q = sdev->request_queue;
void *buf;
/* set the min alignment */
blk_queue_update_dma_alignment(sdev->request_queue,
ATA_DMA_PAD_SZ - 1);
else {
/* configure draining */
buf = kmalloc(ATAPI_MAX_DRAIN, q->bounce_gfp | GFP_KERNEL);
if (!buf) {
ata_dev_printk(dev, KERN_ERR,
"drain buffer allocation failed\n");
return -ENOMEM;
}
blk_queue_dma_drain(q, atapi_drain_needed, buf, ATAPI_MAX_DRAIN);
} else {
/* ATA devices must be sector aligned */
blk_queue_update_dma_alignment(sdev->request_queue,
ATA_SECT_SIZE - 1);
@ -853,6 +892,8 @@ static void ata_scsi_dev_config(struct scsi_device *sdev,
depth = min(ATA_MAX_QUEUE - 1, depth);
scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth);
}
return 0;
}
/**
@ -871,13 +912,14 @@ int ata_scsi_slave_config(struct scsi_device *sdev)
{
struct ata_port *ap = ata_shost_to_port(sdev->host);
struct ata_device *dev = __ata_scsi_find_dev(ap, sdev);
int rc = 0;
ata_scsi_sdev_config(sdev);
if (dev)
ata_scsi_dev_config(sdev, dev);
rc = ata_scsi_dev_config(sdev, dev);
return 0;
return rc;
}
/**
@ -897,6 +939,7 @@ int ata_scsi_slave_config(struct scsi_device *sdev)
void ata_scsi_slave_destroy(struct scsi_device *sdev)
{
struct ata_port *ap = ata_shost_to_port(sdev->host);
struct request_queue *q = sdev->request_queue;
unsigned long flags;
struct ata_device *dev;
@ -912,6 +955,10 @@ void ata_scsi_slave_destroy(struct scsi_device *sdev)
ata_port_schedule_eh(ap);
}
spin_unlock_irqrestore(ap->lock, flags);
kfree(q->dma_drain_buffer);
q->dma_drain_buffer = NULL;
q->dma_drain_size = 0;
}
/**