[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 (file)
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -239,6 +239,49 @@ int ata_rwcmd_protocol(struct ata_queued_cmd *qc)
        return -1;
 }
 
+/**
+ *     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

diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index be2ac39..2d532da 100644 (file)
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -52,6 +52,7 @@ extern int atapi_dmadir;
 extern int libata_fua;
 extern struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev);
 extern int ata_rwcmd_protocol(struct ata_queued_cmd *qc);
+extern u64 ata_tf_read_block(struct ata_taskfile *tf, struct ata_device *dev);
 extern void ata_dev_disable(struct ata_device *dev);
 extern void ata_port_flush_task(struct ata_port *ap);
 extern unsigned ata_exec_internal(struct ata_device *dev,