ide: sanitize ide_build_sglist() and ide_destroy_dmatable()

* Move ide_map_sg() calls out from ide_build_sglist()
  to ide_dma_prepare().

* Pass command to ide_destroy_dmatable().

* Rename ide_build_sglist() to ide_dma_map_sg()
  and ide_destroy_dmatable() to ide_dma_unmap_sg().

There should be no functional changes caused by this patch.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

5 files changed, 35 insertions, 33 deletions

diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c
index db6e617790bd..3f3fc7c7b2fe 100644
--- a/drivers/ide/ide-atapi.c
+++ b/drivers/ide/ide-atapi.c
@@ -326,6 +326,7 @@ static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
 {
         struct ide_atapi_pc *pc = drive->pc;
         ide_hwif_t *hwif = drive->hwif;
+        struct ide_cmd *cmd = &hwif->cmd;
         struct request *rq = hwif->rq;
         const struct ide_tp_ops *tp_ops = hwif->tp_ops;
         xfer_func_t *xferfunc;
@@ -346,7 +347,7 @@ static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
 
                 drive->waiting_for_dma = 0;
                 rc = hwif->dma_ops->dma_end(drive);
-                ide_destroy_dmatable(drive);
+                ide_dma_unmap_sg(drive, cmd);
 
                 if (rc || (drive->media == ide_tape && (stat & ATA_ERR))) {
                         if (drive->media == ide_floppy)
diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index f5c7bb739f45..35729a47f797 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -640,7 +640,7 @@ static ide_startstop_t cdrom_newpc_intr(ide_drive_t *drive)
                 drive->dma = 0;
                 drive->waiting_for_dma = 0;
                 dma_error = hwif->dma_ops->dma_end(drive);
-                ide_destroy_dmatable(drive);
+                ide_dma_unmap_sg(drive, cmd);
                 if (dma_error) {
                         printk(KERN_ERR PFX "%s: DMA %s error\n", drive->name,
                                         write ? "write" : "read");
diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
index 4d3102887d9c..a5612eadc306 100644
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -89,17 +89,16 @@ static const struct drive_list_entry drive_blacklist[] = {
 ide_startstop_t ide_dma_intr(ide_drive_t *drive)
 {
         ide_hwif_t *hwif = drive->hwif;
+        struct ide_cmd *cmd = &hwif->cmd;
         u8 stat = 0, dma_stat = 0;
 
         drive->waiting_for_dma = 0;
         dma_stat = hwif->dma_ops->dma_end(drive);
-        ide_destroy_dmatable(drive);
+        ide_dma_unmap_sg(drive, cmd);
         stat = hwif->tp_ops->read_status(hwif);
 
         if (OK_STAT(stat, DRIVE_READY, drive->bad_wstat | ATA_DRQ)) {
                 if (!dma_stat) {
-                        struct ide_cmd *cmd = &hwif->cmd;
-
                         if ((cmd->tf_flags & IDE_TFLAG_FS) == 0)
                                 ide_finish_cmd(drive, cmd, stat);
                         else
@@ -119,8 +118,8 @@ int ide_dma_good_drive(ide_drive_t *drive)
 }
 
 /**
- *      ide_build_sglist        -       map IDE scatter gather for DMA I/O
- *      @drive: the drive to build the DMA table for
+ *      ide_dma_map_sg  -       map IDE scatter gather for DMA I/O
+ *      @drive: the drive to map the DMA table for
  *      @cmd: command
  *
  *      Perform the DMA mapping magic necessary to access the source or
@@ -129,23 +128,19 @@ int ide_dma_good_drive(ide_drive_t *drive)
  *      operate in a portable fashion.
  */
 
-static int ide_build_sglist(ide_drive_t *drive, struct ide_cmd *cmd)
+static int ide_dma_map_sg(ide_drive_t *drive, struct ide_cmd *cmd)
 {
         ide_hwif_t *hwif = drive->hwif;
         struct scatterlist *sg = hwif->sg_table;
         int i;
 
-        ide_map_sg(drive, cmd);
-
         if (cmd->tf_flags & IDE_TFLAG_WRITE)
                 cmd->sg_dma_direction = DMA_TO_DEVICE;
         else
                 cmd->sg_dma_direction = DMA_FROM_DEVICE;
 
         i = dma_map_sg(hwif->dev, sg, cmd->sg_nents, cmd->sg_dma_direction);
-        if (i == 0)
-                ide_map_sg(drive, cmd);
-        else {
+        if (i) {
                 cmd->orig_sg_nents = cmd->sg_nents;
                 cmd->sg_nents = i;
         }
@@ -154,7 +149,7 @@ static int ide_build_sglist(ide_drive_t *drive, struct ide_cmd *cmd)
 }
 
 /**
- *      ide_destroy_dmatable    -       clean up DMA mapping
+ *      ide_dma_unmap_sg        -       clean up DMA mapping
  *      @drive: The drive to unmap
  *
  *      Teardown mappings after DMA has completed. This must be called
@@ -164,15 +159,14 @@ static int ide_build_sglist(ide_drive_t *drive, struct ide_cmd *cmd)
  *      time.
  */
 
-void ide_destroy_dmatable(ide_drive_t *drive)
+void ide_dma_unmap_sg(ide_drive_t *drive, struct ide_cmd *cmd)
 {
         ide_hwif_t *hwif = drive->hwif;
-        struct ide_cmd *cmd = &hwif->cmd;
 
         dma_unmap_sg(hwif->dev, hwif->sg_table, cmd->orig_sg_nents,
                      cmd->sg_dma_direction);
 }
-EXPORT_SYMBOL_GPL(ide_destroy_dmatable);
+EXPORT_SYMBOL_GPL(ide_dma_unmap_sg);
 
 /**
  *      ide_dma_off_quietly     -       Generic DMA kill
@@ -471,6 +465,7 @@ ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
 {
         ide_hwif_t *hwif = drive->hwif;
         const struct ide_dma_ops *dma_ops = hwif->dma_ops;
+        struct ide_cmd *cmd = &hwif->cmd;
         struct request *rq;
         ide_startstop_t ret = ide_stopped;
 
@@ -482,7 +477,7 @@ ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
                 printk(KERN_WARNING "%s: DMA timeout error\n", drive->name);
                 drive->waiting_for_dma = 0;
                 (void)dma_ops->dma_end(drive);
-                ide_destroy_dmatable(drive);
+                ide_dma_unmap_sg(drive, cmd);
                 ret = ide_error(drive, "dma timeout error",
                                 hwif->tp_ops->read_status(hwif));
         } else {
@@ -495,7 +490,7 @@ ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
                                         hwif->tp_ops->read_status(hwif));
                         drive->waiting_for_dma = 0;
                         (void)dma_ops->dma_end(drive);
-                        ide_destroy_dmatable(drive);
+                        ide_dma_unmap_sg(drive, cmd);
                 }
         }
 
@@ -572,14 +567,19 @@ int ide_dma_prepare(ide_drive_t *drive, struct ide_cmd *cmd)
         const struct ide_dma_ops *dma_ops = drive->hwif->dma_ops;
 
         if ((drive->dev_flags & IDE_DFLAG_USING_DMA) == 0 ||
-            (dma_ops->dma_check && dma_ops->dma_check(drive, cmd)) ||
-            ide_build_sglist(drive, cmd) == 0)
-                return 1;
-        if (dma_ops->dma_setup(drive, cmd)) {
-                ide_destroy_dmatable(drive);
-                ide_map_sg(drive, cmd);
-                return 1;
-        }
+            (dma_ops->dma_check && dma_ops->dma_check(drive, cmd)))
+                goto out;
+        ide_map_sg(drive, cmd);
+        if (ide_dma_map_sg(drive, cmd) == 0)
+                goto out_map;
+        if (dma_ops->dma_setup(drive, cmd))
+                goto out_dma_unmap;
         drive->waiting_for_dma = 1;
         return 0;
+out_dma_unmap:
+        ide_dma_unmap_sg(drive, cmd);
+out_map:
+        ide_map_sg(drive, cmd);
+out:
+        return 1;
 }
diff --git a/drivers/ide/sgiioc4.c b/drivers/ide/sgiioc4.c
index cb2657c4c976..6ef5a567d377 100644
--- a/drivers/ide/sgiioc4.c
+++ b/drivers/ide/sgiioc4.c
@@ -277,11 +277,12 @@ static void sgiioc4_dma_host_set(ide_drive_t *drive, int on)
                 sgiioc4_clearirq(drive);
 }
 
-static void
-sgiioc4_resetproc(ide_drive_t * drive)
+static void sgiioc4_resetproc(ide_drive_t *drive)
 {
+        struct ide_cmd *cmd = &drive->hwif->cmd;
+
         sgiioc4_dma_end(drive);
-        ide_destroy_dmatable(drive);
+        ide_dma_unmap_sg(drive, cmd);
         sgiioc4_clearirq(drive);
 }
 
diff --git a/include/linux/ide.h b/include/linux/ide.h
index b350667b83ad..03c520917b7a 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -1445,8 +1445,7 @@ int ide_allocate_dma_engine(ide_hwif_t *);
 void ide_release_dma_engine(ide_hwif_t *);
 
 int ide_dma_prepare(ide_drive_t *, struct ide_cmd *);
-
-void ide_destroy_dmatable(ide_drive_t *);
+void ide_dma_unmap_sg(ide_drive_t *, struct ide_cmd *);
 
 #ifdef CONFIG_BLK_DEV_IDEDMA_SFF
 int config_drive_for_dma(ide_drive_t *);
@@ -1481,7 +1480,8 @@ static inline ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int erro
 static inline void ide_release_dma_engine(ide_hwif_t *hwif) { ; }
 static inline int ide_dma_prepare(ide_drive_t *drive,
                                   struct ide_cmd *cmd) { return 1; }
-static inline void ide_destroy_dmatable(ide_drive_t *drive) { ; }
+static inline void ide_dma_unmap_sg(ide_drive_t *drive,
+                                    struct ide_cmd *cmd) { ; }
 #endif /* CONFIG_BLK_DEV_IDEDMA */
 
 #ifdef CONFIG_BLK_DEV_IDEACPI