libata: add support for READ/WRITE LONG

The READ/WRITE LONG commands are theoretically obsolete,
but the majority of drives in existance still implement them.

The WRITE_LONG and WRITE_LONG_ONCE commands are of particular
interest for fault injection testing -- eg. creating "media errors"
at specific locations on a disk.

The fussy bit is that these commands require a non-standard
sector size, usually 520 bytes instead of 512.

This patch adds support to libata for READ/WRITE LONG commands
issued via SG_IO/ATA_16.

Signed-off-by:  Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 971a737..96bf86f 100644 (file)
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -4106,10 +4106,10 @@ void ata_data_xfer_noirq(struct ata_device *adev, unsigned char *buf,
 
 
 /**
- *     ata_pio_sector - Transfer ATA_SECT_SIZE (512 bytes) of data.
+ *     ata_pio_sector - Transfer a sector of data.
  *     @qc: Command on going
  *
- *     Transfer ATA_SECT_SIZE of data from/to the ATA device.
+ *     Transfer qc->sect_size bytes of data from/to the ATA device.
  *
  *     LOCKING:
  *     Inherited from caller.
@@ -4124,7 +4124,7 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)
        unsigned int offset;
        unsigned char *buf;
 
-       if (qc->curbytes == qc->nbytes - ATA_SECT_SIZE)
+       if (qc->curbytes == qc->nbytes - qc->sect_size)
                ap->hsm_task_state = HSM_ST_LAST;
 
        page = sg[qc->cursg].page;
@@ -4144,17 +4144,17 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)
                buf = kmap_atomic(page, KM_IRQ0);
 
                /* do the actual data transfer */
-               ap->ops->data_xfer(qc->dev, buf + offset, ATA_SECT_SIZE, do_write);
+               ap->ops->data_xfer(qc->dev, buf + offset, qc->sect_size, do_write);
 
                kunmap_atomic(buf, KM_IRQ0);
                local_irq_restore(flags);
        } else {
                buf = page_address(page);
-               ap->ops->data_xfer(qc->dev, buf + offset, ATA_SECT_SIZE, do_write);
+               ap->ops->data_xfer(qc->dev, buf + offset, qc->sect_size, do_write);
        }
 
-       qc->curbytes += ATA_SECT_SIZE;
-       qc->cursg_ofs += ATA_SECT_SIZE;
+       qc->curbytes += qc->sect_size;
+       qc->cursg_ofs += qc->sect_size;
 
        if (qc->cursg_ofs == (&sg[qc->cursg])->length) {
                qc->cursg++;
@@ -4163,10 +4163,10 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)
 }
 
 /**
- *     ata_pio_sectors - Transfer one or many 512-byte sectors.
+ *     ata_pio_sectors - Transfer one or many sectors.
  *     @qc: Command on going
  *
- *     Transfer one or many ATA_SECT_SIZE of data from/to the
+ *     Transfer one or many sectors of data from/to the
  *     ATA device for the DRQ request.
  *
  *     LOCKING:
@@ -4181,7 +4181,7 @@ static void ata_pio_sectors(struct ata_queued_cmd *qc)
 
                WARN_ON(qc->dev->multi_count == 0);
 
-               nsect = min((qc->nbytes - qc->curbytes) / ATA_SECT_SIZE,
+               nsect = min((qc->nbytes - qc->curbytes) / qc->sect_size,
                            qc->dev->multi_count);
                while (nsect--)
                        ata_pio_sector(qc);

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 7d41afe..563ef0b 100644 (file)
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -2678,6 +2678,18 @@ static unsigned int ata_scsi_pass_thru(struct ata_queued_cmd *qc)
                tf->device = qc->dev->devno ?
                        tf->device | ATA_DEV1 : tf->device & ~ATA_DEV1;
 
+       /* READ/WRITE LONG use a non-standard sect_size */
+       qc->sect_size = ATA_SECT_SIZE;
+       switch (tf->command) {
+       case ATA_CMD_READ_LONG:
+       case ATA_CMD_READ_LONG_ONCE:
+       case ATA_CMD_WRITE_LONG:
+       case ATA_CMD_WRITE_LONG_ONCE:
+               if (tf->protocol != ATA_PROT_PIO || tf->nsect != 1)
+                       goto invalid_fld;
+               qc->sect_size = scmd->request_bufflen;
+       }
+
        /*
         * Filter SET_FEATURES - XFER MODE command -- otherwise,
         * SET_FEATURES - XFER MODE must be preceded/succeeded

diff --git a/include/linux/ata.h b/include/linux/ata.h
index 6caeb98..ffb6cdc 100644 (file)
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -164,6 +164,12 @@ enum {
        /* READ_LOG_EXT pages */
        ATA_LOG_SATA_NCQ        = 0x10,
 
+       /* READ/WRITE LONG (obsolete) */
+       ATA_CMD_READ_LONG       = 0x22,
+       ATA_CMD_READ_LONG_ONCE  = 0x23,
+       ATA_CMD_WRITE_LONG      = 0x32,
+       ATA_CMD_WRITE_LONG_ONCE = 0x33,
+
        /* SETFEATURES stuff */
        SETFEATURES_XFER        = 0x03,
        XFER_UDMA_7             = 0x47,

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 5a40a8d..12237d4 100644 (file)
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -427,6 +427,7 @@ struct ata_queued_cmd {
        int                     dma_dir;
 
        unsigned int            pad_len;
+       unsigned int            sect_size;
 
        unsigned int            nbytes;
        unsigned int            curbytes;
@@ -1182,6 +1183,7 @@ static inline void ata_qc_reinit(struct ata_queued_cmd *qc)
        qc->n_elem = 0;
        qc->err_mask = 0;
        qc->pad_len = 0;
+       qc->sect_size = ATA_SECT_SIZE;
 
        ata_tf_init(qc->dev, &qc->tf);