[PATCH] libata: implement ata_exec_internal_sg()

Sg'ify ata_exec_internal() and call it ata_exec_internal_sg().
Wrapper function around ata_exec_internal_sg() is implemented to
provide ata_exec_internal() interface.

Signed-off-by: Tejun Heo <htejun@gmail.com>

2 files changed, 46 insertions, 7 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 47c70392ec4d..0a5103b707c6 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -1042,13 +1042,13 @@ void ata_qc_complete_internal(struct ata_queued_cmd *qc)
 }
 
 /**
- *      ata_exec_internal - execute libata internal command
+ *      ata_exec_internal_sg - execute libata internal command
  *      @dev: Device to which the command is sent
  *      @tf: Taskfile registers for the command and the result
  *      @cdb: CDB for packet command
  *      @dma_dir: Data tranfer direction of the command
- *      @buf: Data buffer of the command
- *      @buflen: Length of data buffer
+ *      @sg: sg list for the data buffer of the command
+ *      @n_elem: Number of sg entries
  *
  *      Executes libata internal command with timeout.  @tf contains
  *      command on entry and result on return.  Timeout and error
@@ -1062,9 +1062,10 @@ void ata_qc_complete_internal(struct ata_queued_cmd *qc)
  *      RETURNS:
  *      Zero on success, AC_ERR_* mask on failure
  */
-unsigned ata_exec_internal(struct ata_device *dev,
-                           struct ata_taskfile *tf, const u8 *cdb,
-                           int dma_dir, void *buf, unsigned int buflen)
+unsigned ata_exec_internal_sg(struct ata_device *dev,
+                              struct ata_taskfile *tf, const u8 *cdb,
+                              int dma_dir, struct scatterlist *sg,
+                              unsigned int n_elem)
 {
         struct ata_port *ap = dev->ap;
         u8 command = tf->command;
@@ -1120,7 +1121,12 @@ unsigned ata_exec_internal(struct ata_device *dev,
         qc->flags |= ATA_QCFLAG_RESULT_TF;
         qc->dma_dir = dma_dir;
         if (dma_dir != DMA_NONE) {
-                ata_sg_init_one(qc, buf, buflen);
+                unsigned int i, buflen = 0;
+
+                for (i = 0; i < n_elem; i++)
+                        buflen += sg[i].length;
+
+                ata_sg_init(qc, sg, n_elem);
                 qc->nsect = buflen / ATA_SECT_SIZE;
         }
 
@@ -1204,6 +1210,35 @@ unsigned ata_exec_internal(struct ata_device *dev,
 }
 
 /**
+ *      ata_exec_internal_sg - execute libata internal command
+ *      @dev: Device to which the command is sent
+ *      @tf: Taskfile registers for the command and the result
+ *      @cdb: CDB for packet command
+ *      @dma_dir: Data tranfer direction of the command
+ *      @buf: Data buffer of the command
+ *      @buflen: Length of data buffer
+ *
+ *      Wrapper around ata_exec_internal_sg() which takes simple
+ *      buffer instead of sg list.
+ *
+ *      LOCKING:
+ *      None.  Should be called with kernel context, might sleep.
+ *
+ *      RETURNS:
+ *      Zero on success, AC_ERR_* mask on failure
+ */
+unsigned ata_exec_internal(struct ata_device *dev,
+                           struct ata_taskfile *tf, const u8 *cdb,
+                           int dma_dir, void *buf, unsigned int buflen)
+{
+        struct scatterlist sg;
+
+        sg_init_one(&sg, buf, buflen);
+
+        return ata_exec_internal_sg(dev, tf, cdb, dma_dir, &sg, 1);
+}
+
+/**
  *      ata_do_simple_cmd - execute simple internal command
  *      @dev: Device to which the command is sent
  *      @cmd: Opcode to execute
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 2d532da8c398..ca6f36c13115 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -58,6 +58,10 @@ extern void ata_port_flush_task(struct ata_port *ap);
 extern unsigned ata_exec_internal(struct ata_device *dev,
                                   struct ata_taskfile *tf, const u8 *cdb,
                                   int dma_dir, void *buf, unsigned int buflen);
+extern unsigned ata_exec_internal_sg(struct ata_device *dev,
+                                     struct ata_taskfile *tf, const u8 *cdb,
+                                     int dma_dir, struct scatterlist *sg,
+                                     unsigned int n_elem);
 extern unsigned int ata_do_simple_cmd(struct ata_device *dev, u8 cmd);
 extern int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
                            unsigned int flags, u16 *id);