[PATCH] libata: implement ata_tf_read_block()
Implement ata_tf_read_block().
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 13dcef8..3fd7c79 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -240,6 +240,49 @@
}
/**
+ * ata_tf_read_block - Read block address from ATA taskfile
+ * @tf: ATA taskfile of interest
+ * @dev: ATA device @tf belongs to
+ *
+ * LOCKING:
+ * None.
+ *
+ * Read block address from @tf. This function can handle all
+ * three address formats - LBA, LBA48 and CHS. tf->protocol and
+ * flags select the address format to use.
+ *
+ * RETURNS:
+ * Block address read from @tf.
+ */
+u64 ata_tf_read_block(struct ata_taskfile *tf, struct ata_device *dev)
+{
+ u64 block = 0;
+
+ if (tf->flags & ATA_TFLAG_LBA) {
+ if (tf->flags & ATA_TFLAG_LBA48) {
+ block |= (u64)tf->hob_lbah << 40;
+ block |= (u64)tf->hob_lbam << 32;
+ block |= tf->hob_lbal << 24;
+ } else
+ block |= (tf->device & 0xf) << 24;
+
+ block |= tf->lbah << 16;
+ block |= tf->lbam << 8;
+ block |= tf->lbal;
+ } else {
+ u32 cyl, head, sect;
+
+ cyl = tf->lbam | (tf->lbah << 8);
+ head = tf->device & 0xf;
+ sect = tf->lbal;
+
+ block = (cyl * dev->heads + head) * dev->sectors + sect;
+ }
+
+ return block;
+}
+
+/**
* ata_pack_xfermask - Pack pio, mwdma and udma masks into xfer_mask
* @pio_mask: pio_mask
* @mwdma_mask: mwdma_mask