[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 55d4dee..19d3d71 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -616,79 +616,53 @@
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_set_mode(struct ata_port *ap)
{
- unsigned int i, xfer_shift;
+ unsigned int xfer_shift;
u8 xfer_mode;
int rc;
@@ -1670,11 +1644,6 @@
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: