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 db6e617..3f3fc7c 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 f5c7bb7..35729a4 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 4d31028..a5612ea 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 cb2657c..6ef5a56 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 b350667..03c5209 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