[PATCH] libata CHS: calculate read/write commands and protocol on the fly (revise #6)

     - merge ata_prot_to_cmd() and ata_dev_set_protocol() as
       ata_rwcmd_protocol()
     - pave road for read/write multiple support
     - remove usage of pre-cached command and protocol values and call
       ata_rwcmd_protocol() instead

Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
==============
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 55d4dee133aff1f6b3a088a7ffcf0f7ea6229871..19d3d717faf67d22ad9d007bb77fa1aa73538ae8 100644 (file)
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -616,79 +616,53 @@ void ata_tf_from_fis(u8 *fis, struct ata_taskfile *tf)
        tf->hob_nsect   = fis[13];
 }
 
-/**
- *     ata_prot_to_cmd - determine which read/write opcodes to use
- *     @protocol: ATA_PROT_xxx taskfile protocol
- *     @lba48: true is lba48 is present
- *
- *     Given necessary input, determine which read/write commands
- *     to use to transfer data.
- *
- *     LOCKING:
- *     None.
- */
-static int ata_prot_to_cmd(int protocol, int lba48)
-{
-       int rcmd = 0, wcmd = 0;
-
-       switch (protocol) {
-       case ATA_PROT_PIO:
-               if (lba48) {
-                       rcmd = ATA_CMD_PIO_READ_EXT;
-                       wcmd = ATA_CMD_PIO_WRITE_EXT;
-               } else {
-                       rcmd = ATA_CMD_PIO_READ;
-                       wcmd = ATA_CMD_PIO_WRITE;
-               }
-               break;
-
-       case ATA_PROT_DMA:
-               if (lba48) {
-                       rcmd = ATA_CMD_READ_EXT;
-                       wcmd = ATA_CMD_WRITE_EXT;
-               } else {
-                       rcmd = ATA_CMD_READ;
-                       wcmd = ATA_CMD_WRITE;
-               }
-               break;
-
-       default:
-               return -1;
-       }
-
-       return rcmd | (wcmd << 8);
-}
+static const u8 ata_rw_cmds[] = {
+       /* pio multi */
+       ATA_CMD_READ_MULTI,
+       ATA_CMD_WRITE_MULTI,
+       ATA_CMD_READ_MULTI_EXT,
+       ATA_CMD_WRITE_MULTI_EXT,
+       /* pio */
+       ATA_CMD_PIO_READ,
+       ATA_CMD_PIO_WRITE,
+       ATA_CMD_PIO_READ_EXT,
+       ATA_CMD_PIO_WRITE_EXT,
+       /* dma */
+       ATA_CMD_READ,
+       ATA_CMD_WRITE,
+       ATA_CMD_READ_EXT,
+       ATA_CMD_WRITE_EXT
+};
 
 /**
- *     ata_dev_set_protocol - set taskfile protocol and r/w commands
- *     @dev: device to examine and configure
+ *     ata_rwcmd_protocol - set taskfile r/w commands and protocol
+ *     @qc: command to examine and configure
  *
- *     Examine the device configuration, after we have
- *     read the identify-device page and configured the
- *     data transfer mode.  Set internal state related to
- *     the ATA taskfile protocol (pio, pio mult, dma, etc.)
- *     and calculate the proper read/write commands to use.
+ *     Examine the device configuration and tf->flags to calculate 
+ *     the proper read/write commands and protocol to use.
  *
  *     LOCKING:
  *     caller.
  */
-static void ata_dev_set_protocol(struct ata_device *dev)
+void ata_rwcmd_protocol(struct ata_queued_cmd *qc)
 {
-       int pio = (dev->flags & ATA_DFLAG_PIO);
-       int lba48 = (dev->flags & ATA_DFLAG_LBA48);
-       int proto, cmd;
+       struct ata_taskfile *tf = &qc->tf;
+       struct ata_device *dev = qc->dev;
 
-       if (pio)
-               proto = dev->xfer_protocol = ATA_PROT_PIO;
-       else
-               proto = dev->xfer_protocol = ATA_PROT_DMA;
+       int index, lba48, write;
+ 
+       lba48 = (tf->flags & ATA_TFLAG_LBA48) ? 2 : 0;
+       write = (tf->flags & ATA_TFLAG_WRITE) ? 1 : 0;
 
-       cmd = ata_prot_to_cmd(proto, lba48);
-       if (cmd < 0)
-               BUG();
+       if (dev->flags & ATA_DFLAG_PIO) {
+               tf->protocol = ATA_PROT_PIO;
+               index = dev->multi_count ? 0 : 4;
+       } else {
+               tf->protocol = ATA_PROT_DMA;
+               index = 8;
+       }
 
-       dev->read_cmd = cmd & 0xff;
-       dev->write_cmd = (cmd >> 8) & 0xff;
+       tf->command = ata_rw_cmds[index + lba48 + write];
 }
 
 static const char * xfer_mode_str[] = {
@@ -1641,7 +1615,7 @@ static void ata_host_set_dma(struct ata_port *ap, u8 xfer_mode,
  */
 static void ata_set_mode(struct ata_port *ap)
 {
-       unsigned int i, xfer_shift;
+       unsigned int xfer_shift;
        u8 xfer_mode;
        int rc;
 
@@ -1670,11 +1644,6 @@ static void ata_set_mode(struct ata_port *ap)
        if (ap->ops->post_set_mode)
                ap->ops->post_set_mode(ap);
 
-       for (i = 0; i < 2; i++) {
-               struct ata_device *dev = &ap->device[i];
-               ata_dev_set_protocol(dev);
-       }
-
        return;
 
 err_out:

diff --git a/drivers/scsi/libata-scsi.c b/drivers/scsi/libata-scsi.c
index ea7a4d8a6fc9fd487d0f6bf4a9184f57c4c58ab8..90bf22204668c1828934c598db6492a9a1d96de7 100644 (file)
--- a/drivers/scsi/libata-scsi.c
+++ b/drivers/scsi/libata-scsi.c
@@ -742,15 +742,10 @@ static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc, u8 *scsicmd)
        u32 n_block;
 
        tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
-       tf->protocol = qc->dev->xfer_protocol;
 
-       if (scsicmd[0] == READ_10 || scsicmd[0] == READ_6 ||
-           scsicmd[0] == READ_16) {
-               tf->command = qc->dev->read_cmd;
-       } else {
-               tf->command = qc->dev->write_cmd;
+       if (scsicmd[0] == WRITE_10 || scsicmd[0] == WRITE_6 ||
+           scsicmd[0] == WRITE_16)
                tf->flags |= ATA_TFLAG_WRITE;
-       }
 
        /* Calculate the SCSI LBA and transfer length. */
        switch (scsicmd[0]) {
@@ -812,6 +807,8 @@ static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc, u8 *scsicmd)
                        tf->device |= (block >> 24) & 0xf;
                }
 
+               ata_rwcmd_protocol(qc);
+
                qc->nsect = n_block;
                tf->nsect = n_block & 0xff;
 
@@ -828,6 +825,8 @@ static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc, u8 *scsicmd)
                if ((block >> 28) || (n_block > 256))
                        goto out_of_range;
 
+               ata_rwcmd_protocol(qc);
+
                /* Convert LBA to CHS */
                track = (u32)block / dev->sectors;
                cyl   = track / dev->heads;

diff --git a/drivers/scsi/libata.h b/drivers/scsi/libata.h
index a18f2ac1d4a132484a274436c1631f209fda4ac8..67d752ca8ae2e5fd3115ac41867c4d6f651b0602 100644 (file)
--- a/drivers/scsi/libata.h
+++ b/drivers/scsi/libata.h
@@ -42,6 +42,7 @@ extern int atapi_enabled;
 extern int ata_qc_complete_noop(struct ata_queued_cmd *qc, u8 drv_stat);
 extern struct ata_queued_cmd *ata_qc_new_init(struct ata_port *ap,
                                      struct ata_device *dev);
+extern void ata_rwcmd_protocol(struct ata_queued_cmd *qc);
 extern void ata_qc_free(struct ata_queued_cmd *qc);
 extern int ata_qc_issue(struct ata_queued_cmd *qc);
 extern int ata_check_atapi_dma(struct ata_queued_cmd *qc);

diff --git a/include/linux/ata.h b/include/linux/ata.h
index ecb7346d0c166cb9185664886925d9bf4150e239..630908c9378b45f3ed65bf1118171ff1cbd904dd 100644 (file)
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -128,6 +128,10 @@ enum {
        ATA_CMD_PIO_READ_EXT    = 0x24,
        ATA_CMD_PIO_WRITE       = 0x30,
        ATA_CMD_PIO_WRITE_EXT   = 0x34,
+       ATA_CMD_READ_MULTI      = 0xC4,
+       ATA_CMD_READ_MULTI_EXT  = 0x29,
+       ATA_CMD_WRITE_MULTI     = 0xC5,
+       ATA_CMD_WRITE_MULTI_EXT = 0x39,
        ATA_CMD_SET_FEATURES    = 0xEF,
        ATA_CMD_PACKET          = 0xA0,
        ATA_CMD_VERIFY          = 0x40,

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 7929cfc9318d0b42aa7fb7da018987fd567fabef..0261c55f34837a4049e9651770cbabb7304efa9b 100644 (file)
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -283,10 +283,8 @@ struct ata_device {
        u8                      xfer_mode;
        unsigned int            xfer_shift;     /* ATA_SHIFT_xxx */
 
-       /* cache info about current transfer mode */
-       u8                      xfer_protocol;  /* taskfile xfer protocol */
-       u8                      read_cmd;       /* opcode to use on read */
-       u8                      write_cmd;      /* opcode to use on write */
+       unsigned int            multi_count;    /* sectors count for
+                                                  READ/WRITE MULTIPLE */
 
        /* for CHS addressing */
        u16                     cylinders;      /* Number of cylinders */