scsi: esp_scsi: move dma mapping into the core code

Except for the mac_esp driver, which uses PIO or pseudo DMA, all drivers
share the same dma mapping calls.  Move the dma mapping into the core
code using the scsi_dma_map / scsi_dma_unmap helpers, with a special
identify mapping variant triggered off a new ESP_FLAG_NO_DMA_MAP flag
for mac_esp.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/am53c974.c

@@ -114,30 +114,6 @@ static void pci_esp_write32(struct esp *esp, u32 val, unsigned long reg)
 	return iowrite32(val, esp->regs + (reg * 4UL));
 }
 
-static dma_addr_t pci_esp_map_single(struct esp *esp, void *buf,
-				     size_t sz, int dir)
-{
-	return dma_map_single(esp->dev, buf, sz, dir);
-}
-
-static int pci_esp_map_sg(struct esp *esp, struct scatterlist *sg,
-			  int num_sg, int dir)
-{
-	return dma_map_sg(esp->dev, sg, num_sg, dir);
-}
-
-static void pci_esp_unmap_single(struct esp *esp, dma_addr_t addr,
-				 size_t sz, int dir)
-{
-	dma_unmap_single(esp->dev, addr, sz, dir);
-}
-
-static void pci_esp_unmap_sg(struct esp *esp, struct scatterlist *sg,
-			     int num_sg, int dir)
-{
-	dma_unmap_sg(esp->dev, sg, num_sg, dir);
-}
-
 static int pci_esp_irq_pending(struct esp *esp)
 {
 	struct pci_esp_priv *pep = pci_esp_get_priv(esp);
@@ -293,10 +269,6 @@ static u32 pci_esp_dma_length_limit(struct esp *esp, u32 dma_addr, u32 dma_len)
 static const struct esp_driver_ops pci_esp_ops = {
 	.esp_write8	=	pci_esp_write8,
 	.esp_read8	=	pci_esp_read8,
-	.map_single	=	pci_esp_map_single,
-	.map_sg		=	pci_esp_map_sg,
-	.unmap_single	=	pci_esp_unmap_single,
-	.unmap_sg	=	pci_esp_unmap_sg,
 	.irq_pending	=	pci_esp_irq_pending,
 	.reset_dma	=	pci_esp_reset_dma,
 	.dma_drain	=	pci_esp_dma_drain,

drivers/scsi/esp_scsi.c

@@ -369,19 +369,28 @@ static void esp_map_dma(struct esp *esp, struct scsi_cmnd *cmd)
 {
 	struct esp_cmd_priv *spriv = ESP_CMD_PRIV(cmd);
 	struct scatterlist *sg = scsi_sglist(cmd);
-	int dir = cmd->sc_data_direction;
-	int total, i;
+	int total = 0, i;
 
-	if (dir == DMA_NONE)
+	if (cmd->sc_data_direction == DMA_NONE)
 		return;
 
-	spriv->u.num_sg = esp->ops->map_sg(esp, sg, scsi_sg_count(cmd), dir);
+	if (esp->flags & ESP_FLAG_NO_DMA_MAP) {
+		/*
+		 * For pseudo DMA and PIO we need the virtual address instead of
+		 * a dma address, so perform an identity mapping.
+		 */
+		spriv->u.num_sg = scsi_sg_count(cmd);
+		for (i = 0; i < spriv->u.num_sg; i++) {
+			sg[i].dma_address = (uintptr_t)sg_virt(&sg[i]);
+			total += sg_dma_len(&sg[i]);
+		}
+	} else {
+		spriv->u.num_sg = scsi_dma_map(cmd);
+		for (i = 0; i < spriv->u.num_sg; i++)
+			total += sg_dma_len(&sg[i]);
+	}
 	spriv->cur_residue = sg_dma_len(sg);
 	spriv->cur_sg = sg;
-
-	total = 0;
-	for (i = 0; i < spriv->u.num_sg; i++)
-		total += sg_dma_len(&sg[i]);
 	spriv->tot_residue = total;
 }
 
@@ -441,13 +450,8 @@ static void esp_advance_dma(struct esp *esp, struct esp_cmd_entry *ent,
 
 static void esp_unmap_dma(struct esp *esp, struct scsi_cmnd *cmd)
 {
-	struct esp_cmd_priv *spriv = ESP_CMD_PRIV(cmd);
-	int dir = cmd->sc_data_direction;
-
-	if (dir == DMA_NONE)
-		return;
-
-	esp->ops->unmap_sg(esp, scsi_sglist(cmd), spriv->u.num_sg, dir);
+	if (!(esp->flags & ESP_FLAG_NO_DMA_MAP))
+		scsi_dma_unmap(cmd);
 }
 
 static void esp_save_pointers(struct esp *esp, struct esp_cmd_entry *ent)
@@ -624,6 +628,26 @@ static void esp_free_lun_tag(struct esp_cmd_entry *ent,
 	}
 }
 
+static void esp_map_sense(struct esp *esp, struct esp_cmd_entry *ent)
+{
+	ent->sense_ptr = ent->cmd->sense_buffer;
+	if (esp->flags & ESP_FLAG_NO_DMA_MAP) {
+		ent->sense_dma = (uintptr_t)ent->sense_ptr;
+		return;
+	}
+
+	ent->sense_dma = dma_map_single(esp->dev, ent->sense_ptr,
+					SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
+}
+
+static void esp_unmap_sense(struct esp *esp, struct esp_cmd_entry *ent)
+{
+	if (!(esp->flags & ESP_FLAG_NO_DMA_MAP))
+		dma_unmap_single(esp->dev, ent->sense_dma,
+				 SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
+	ent->sense_ptr = NULL;
+}
+
 /* When a contingent allegiance conditon is created, we force feed a
  * REQUEST_SENSE command to the device to fetch the sense data.  I
  * tried many other schemes, relying on the scsi error handling layer
@@ -645,12 +669,7 @@ static void esp_autosense(struct esp *esp, struct esp_cmd_entry *ent)
 	if (!ent->sense_ptr) {
 		esp_log_autosense("Doing auto-sense for tgt[%d] lun[%d]\n",
 				  tgt, lun);
-
-		ent->sense_ptr = cmd->sense_buffer;
-		ent->sense_dma = esp->ops->map_single(esp,
-						      ent->sense_ptr,
-						      SCSI_SENSE_BUFFERSIZE,
-						      DMA_FROM_DEVICE);
+		esp_map_sense(esp, ent);
 	}
 	ent->saved_sense_ptr = ent->sense_ptr;
 
@@ -902,9 +921,7 @@ static void esp_cmd_is_done(struct esp *esp, struct esp_cmd_entry *ent,
 	}
 
 	if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
-		esp->ops->unmap_single(esp, ent->sense_dma,
-				       SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
-		ent->sense_ptr = NULL;
+		esp_unmap_sense(esp, ent);
 
 		/* Restore the message/status bytes to what we actually
 		 * saw originally.  Also, report that we are providing
@@ -1256,10 +1273,7 @@ static int esp_finish_select(struct esp *esp)
 			esp->cmd_bytes_ptr = NULL;
 			esp->cmd_bytes_left = 0;
 		} else {
-			esp->ops->unmap_single(esp, ent->sense_dma,
-					       SCSI_SENSE_BUFFERSIZE,
-					       DMA_FROM_DEVICE);
-			ent->sense_ptr = NULL;
+			esp_unmap_sense(esp, ent);
 		}
 
 		/* Now that the state is unwound properly, put back onto
@@ -2039,11 +2053,8 @@ static void esp_reset_cleanup_one(struct esp *esp, struct esp_cmd_entry *ent)
 	esp_free_lun_tag(ent, cmd->device->hostdata);
 	cmd->result = DID_RESET << 16;
 
-	if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
-		esp->ops->unmap_single(esp, ent->sense_dma,
-				       SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
-		ent->sense_ptr = NULL;
-	}
+	if (ent->flags & ESP_CMD_FLAG_AUTOSENSE)
+		esp_unmap_sense(esp, ent);
 
 	cmd->scsi_done(cmd);
 	list_del(&ent->list);

drivers/scsi/esp_scsi.h

@@ -363,19 +363,6 @@ struct esp_driver_ops {
 	void (*esp_write8)(struct esp *esp, u8 val, unsigned long reg);
 	u8 (*esp_read8)(struct esp *esp, unsigned long reg);
 
-	/* Map and unmap DMA memory.  Eventually the driver will be
-	 * converted to the generic DMA API as soon as SBUS is able to
-	 * cope with that.  At such time we can remove this.
-	 */
-	dma_addr_t (*map_single)(struct esp *esp, void *buf,
-				 size_t sz, int dir);
-	int (*map_sg)(struct esp *esp, struct scatterlist *sg,
-		      int num_sg, int dir);
-	void (*unmap_single)(struct esp *esp, dma_addr_t addr,
-			     size_t sz, int dir);
-	void (*unmap_sg)(struct esp *esp, struct scatterlist *sg,
-			 int num_sg, int dir);
-
 	/* Return non-zero if there is an IRQ pending.  Usually this
 	 * status bit lives in the DMA controller sitting in front of
 	 * the ESP.  This has to be accurate or else the ESP interrupt
@@ -495,6 +482,7 @@ struct esp {
 #define ESP_FLAG_QUICKIRQ_CHECK	0x00000010
 #define ESP_FLAG_DISABLE_SYNC	0x00000020
 #define ESP_FLAG_USE_FIFO	0x00000040
+#define ESP_FLAG_NO_DMA_MAP	0x00000080
 
 	u8			select_state;
 #define ESP_SELECT_NONE		0x00 /* Not selecting */

drivers/scsi/jazz_esp.c

@@ -38,30 +38,6 @@ static u8 jazz_esp_read8(struct esp *esp, unsigned long reg)
 	return *(volatile u8 *)(esp->regs + reg);
 }
 
-static dma_addr_t jazz_esp_map_single(struct esp *esp, void *buf,
-				      size_t sz, int dir)
-{
-	return dma_map_single(esp->dev, buf, sz, dir);
-}
-
-static int jazz_esp_map_sg(struct esp *esp, struct scatterlist *sg,
-				  int num_sg, int dir)
-{
-	return dma_map_sg(esp->dev, sg, num_sg, dir);
-}
-
-static void jazz_esp_unmap_single(struct esp *esp, dma_addr_t addr,
-				  size_t sz, int dir)
-{
-	dma_unmap_single(esp->dev, addr, sz, dir);
-}
-
-static void jazz_esp_unmap_sg(struct esp *esp, struct scatterlist *sg,
-			      int num_sg, int dir)
-{
-	dma_unmap_sg(esp->dev, sg, num_sg, dir);
-}
-
 static int jazz_esp_irq_pending(struct esp *esp)
 {
 	if (jazz_esp_read8(esp, ESP_STATUS) & ESP_STAT_INTR)
@@ -117,10 +93,6 @@ static int jazz_esp_dma_error(struct esp *esp)
 static const struct esp_driver_ops jazz_esp_ops = {
 	.esp_write8	=	jazz_esp_write8,
 	.esp_read8	=	jazz_esp_read8,
-	.map_single	=	jazz_esp_map_single,
-	.map_sg		=	jazz_esp_map_sg,
-	.unmap_single	=	jazz_esp_unmap_single,
-	.unmap_sg	=	jazz_esp_unmap_sg,
 	.irq_pending	=	jazz_esp_irq_pending,
 	.reset_dma	=	jazz_esp_reset_dma,
 	.dma_drain	=	jazz_esp_dma_drain,

drivers/scsi/mac_esp.c

@@ -70,38 +70,6 @@ static inline u8 mac_esp_read8(struct esp *esp, unsigned long reg)
 	return nubus_readb(esp->regs + reg * 16);
 }
 
-/* For pseudo DMA and PIO we need the virtual address
- * so this address mapping is the identity mapping.
- */
-
-static dma_addr_t mac_esp_map_single(struct esp *esp, void *buf,
-				     size_t sz, int dir)
-{
-	return (dma_addr_t)buf;
-}
-
-static int mac_esp_map_sg(struct esp *esp, struct scatterlist *sg,
-			  int num_sg, int dir)
-{
-	int i;
-
-	for (i = 0; i < num_sg; i++)
-		sg[i].dma_address = (u32)sg_virt(&sg[i]);
-	return num_sg;
-}
-
-static void mac_esp_unmap_single(struct esp *esp, dma_addr_t addr,
-				 size_t sz, int dir)
-{
-	/* Nothing to do. */
-}
-
-static void mac_esp_unmap_sg(struct esp *esp, struct scatterlist *sg,
-			     int num_sg, int dir)
-{
-	/* Nothing to do. */
-}
-
 static void mac_esp_reset_dma(struct esp *esp)
 {
 	/* Nothing to do. */
@@ -469,10 +437,6 @@ static irqreturn_t mac_scsi_esp_intr(int irq, void *dev_id)
 static struct esp_driver_ops mac_esp_ops = {
 	.esp_write8       = mac_esp_write8,
 	.esp_read8        = mac_esp_read8,
-	.map_single       = mac_esp_map_single,
-	.map_sg           = mac_esp_map_sg,
-	.unmap_single     = mac_esp_unmap_single,
-	.unmap_sg         = mac_esp_unmap_sg,
 	.irq_pending      = mac_esp_irq_pending,
 	.dma_length_limit = mac_esp_dma_length_limit,
 	.reset_dma        = mac_esp_reset_dma,
@@ -552,11 +516,12 @@ static int esp_mac_probe(struct platform_device *dev)
 	}
 
 	esp->ops = &mac_esp_ops;
+	esp->flags = ESP_FLAG_NO_DMA_MAP;
 	if (mep->pdma_io == NULL) {
 		printk(KERN_INFO PFX "using PIO for controller %d\n", dev->id);
 		esp_write8(0, ESP_TCLOW);
 		esp_write8(0, ESP_TCMED);
-		esp->flags = ESP_FLAG_DISABLE_SYNC;
+		esp->flags |= ESP_FLAG_DISABLE_SYNC;
 		mac_esp_ops.send_dma_cmd = mac_esp_send_pio_cmd;
 	} else {
 		printk(KERN_INFO PFX "using PDMA for controller %d\n", dev->id);

drivers/scsi/sun3x_esp.c

@@ -60,30 +60,6 @@ static u8 sun3x_esp_read8(struct esp *esp, unsigned long reg)
 	return readb(esp->regs + (reg * 4UL));
 }
 
-static dma_addr_t sun3x_esp_map_single(struct esp *esp, void *buf,
-				      size_t sz, int dir)
-{
-	return dma_map_single(esp->dev, buf, sz, dir);
-}
-
-static int sun3x_esp_map_sg(struct esp *esp, struct scatterlist *sg,
-				  int num_sg, int dir)
-{
-	return dma_map_sg(esp->dev, sg, num_sg, dir);
-}
-
-static void sun3x_esp_unmap_single(struct esp *esp, dma_addr_t addr,
-				  size_t sz, int dir)
-{
-	dma_unmap_single(esp->dev, addr, sz, dir);
-}
-
-static void sun3x_esp_unmap_sg(struct esp *esp, struct scatterlist *sg,
-			      int num_sg, int dir)
-{
-	dma_unmap_sg(esp->dev, sg, num_sg, dir);
-}
-
 static int sun3x_esp_irq_pending(struct esp *esp)
 {
 	if (dma_read32(DMA_CSR) & (DMA_HNDL_INTR | DMA_HNDL_ERROR))
@@ -182,10 +158,6 @@ static int sun3x_esp_dma_error(struct esp *esp)
 static const struct esp_driver_ops sun3x_esp_ops = {
 	.esp_write8	=	sun3x_esp_write8,
 	.esp_read8	=	sun3x_esp_read8,
-	.map_single	=	sun3x_esp_map_single,
-	.map_sg		=	sun3x_esp_map_sg,
-	.unmap_single	=	sun3x_esp_unmap_single,
-	.unmap_sg	=	sun3x_esp_unmap_sg,
 	.irq_pending	=	sun3x_esp_irq_pending,
 	.reset_dma	=	sun3x_esp_reset_dma,
 	.dma_drain	=	sun3x_esp_dma_drain,

drivers/scsi/sun_esp.c

@@ -210,30 +210,6 @@ static u8 sbus_esp_read8(struct esp *esp, unsigned long reg)
 	return sbus_readb(esp->regs + (reg * 4UL));
 }
 
-static dma_addr_t sbus_esp_map_single(struct esp *esp, void *buf,
-				      size_t sz, int dir)
-{
-	return dma_map_single(esp->dev, buf, sz, dir);
-}
-
-static int sbus_esp_map_sg(struct esp *esp, struct scatterlist *sg,
-				  int num_sg, int dir)
-{
-	return dma_map_sg(esp->dev, sg, num_sg, dir);
-}
-
-static void sbus_esp_unmap_single(struct esp *esp, dma_addr_t addr,
-				  size_t sz, int dir)
-{
-	dma_unmap_single(esp->dev, addr, sz, dir);
-}
-
-static void sbus_esp_unmap_sg(struct esp *esp, struct scatterlist *sg,
-			      int num_sg, int dir)
-{
-	dma_unmap_sg(esp->dev, sg, num_sg, dir);
-}
-
 static int sbus_esp_irq_pending(struct esp *esp)
 {
 	if (dma_read32(DMA_CSR) & (DMA_HNDL_INTR | DMA_HNDL_ERROR))
@@ -463,10 +439,6 @@ static int sbus_esp_dma_error(struct esp *esp)
 static const struct esp_driver_ops sbus_esp_ops = {
 	.esp_write8	=	sbus_esp_write8,
 	.esp_read8	=	sbus_esp_read8,
-	.map_single	=	sbus_esp_map_single,
-	.map_sg		=	sbus_esp_map_sg,
-	.unmap_single	=	sbus_esp_unmap_single,
-	.unmap_sg	=	sbus_esp_unmap_sg,
 	.irq_pending	=	sbus_esp_irq_pending,
 	.reset_dma	=	sbus_esp_reset_dma,
 	.dma_drain	=	sbus_esp_dma_drain,

drivers/scsi/zorro_esp.c

@@ -182,30 +182,6 @@ static u8 zorro_esp_read8(struct esp *esp, unsigned long reg)
 	return readb(esp->regs + (reg * 4UL));
 }
 
-static dma_addr_t zorro_esp_map_single(struct esp *esp, void *buf,
-				      size_t sz, int dir)
-{
-	return dma_map_single(esp->dev, buf, sz, dir);
-}
-
-static int zorro_esp_map_sg(struct esp *esp, struct scatterlist *sg,
-				  int num_sg, int dir)
-{
-	return dma_map_sg(esp->dev, sg, num_sg, dir);
-}
-
-static void zorro_esp_unmap_single(struct esp *esp, dma_addr_t addr,
-				  size_t sz, int dir)
-{
-	dma_unmap_single(esp->dev, addr, sz, dir);
-}
-
-static void zorro_esp_unmap_sg(struct esp *esp, struct scatterlist *sg,
-			      int num_sg, int dir)
-{
-	dma_unmap_sg(esp->dev, sg, num_sg, dir);
-}
-
 static int zorro_esp_irq_pending(struct esp *esp)
 {
 	/* check ESP status register; DMA has no status reg. */
@@ -739,10 +715,6 @@ static int zorro_esp_dma_error(struct esp *esp)
 static const struct esp_driver_ops blz1230_esp_ops = {
 	.esp_write8		= zorro_esp_write8,
 	.esp_read8		= zorro_esp_read8,
-	.map_single		= zorro_esp_map_single,
-	.map_sg			= zorro_esp_map_sg,
-	.unmap_single		= zorro_esp_unmap_single,
-	.unmap_sg		= zorro_esp_unmap_sg,
 	.irq_pending		= zorro_esp_irq_pending,
 	.dma_length_limit	= zorro_esp_dma_length_limit,
 	.reset_dma		= zorro_esp_reset_dma,
@@ -755,10 +727,6 @@ static const struct esp_driver_ops blz1230_esp_ops = {
 static const struct esp_driver_ops blz1230II_esp_ops = {
 	.esp_write8		= zorro_esp_write8,
 	.esp_read8		= zorro_esp_read8,
-	.map_single		= zorro_esp_map_single,
-	.map_sg			= zorro_esp_map_sg,
-	.unmap_single		= zorro_esp_unmap_single,
-	.unmap_sg		= zorro_esp_unmap_sg,
 	.irq_pending		= zorro_esp_irq_pending,
 	.dma_length_limit	= zorro_esp_dma_length_limit,
 	.reset_dma		= zorro_esp_reset_dma,
@@ -771,10 +739,6 @@ static const struct esp_driver_ops blz1230II_esp_ops = {
 static const struct esp_driver_ops blz2060_esp_ops = {
 	.esp_write8		= zorro_esp_write8,
 	.esp_read8		= zorro_esp_read8,
-	.map_single		= zorro_esp_map_single,
-	.map_sg			= zorro_esp_map_sg,
-	.unmap_single		= zorro_esp_unmap_single,
-	.unmap_sg		= zorro_esp_unmap_sg,
 	.irq_pending		= zorro_esp_irq_pending,
 	.dma_length_limit	= zorro_esp_dma_length_limit,
 	.reset_dma		= zorro_esp_reset_dma,
@@ -787,10 +751,6 @@ static const struct esp_driver_ops blz2060_esp_ops = {
 static const struct esp_driver_ops cyber_esp_ops = {
 	.esp_write8		= zorro_esp_write8,
 	.esp_read8		= zorro_esp_read8,
-	.map_single		= zorro_esp_map_single,
-	.map_sg			= zorro_esp_map_sg,
-	.unmap_single		= zorro_esp_unmap_single,
-	.unmap_sg		= zorro_esp_unmap_sg,
 	.irq_pending		= cyber_esp_irq_pending,
 	.dma_length_limit	= zorro_esp_dma_length_limit,
 	.reset_dma		= zorro_esp_reset_dma,
@@ -803,10 +763,6 @@ static const struct esp_driver_ops cyber_esp_ops = {
 static const struct esp_driver_ops cyberII_esp_ops = {
 	.esp_write8		= zorro_esp_write8,
 	.esp_read8		= zorro_esp_read8,
-	.map_single		= zorro_esp_map_single,
-	.map_sg			= zorro_esp_map_sg,
-	.unmap_single		= zorro_esp_unmap_single,
-	.unmap_sg		= zorro_esp_unmap_sg,
 	.irq_pending		= zorro_esp_irq_pending,
 	.dma_length_limit	= zorro_esp_dma_length_limit,
 	.reset_dma		= zorro_esp_reset_dma,
@@ -819,10 +775,6 @@ static const struct esp_driver_ops cyberII_esp_ops = {
 static const struct esp_driver_ops fastlane_esp_ops = {
 	.esp_write8		= zorro_esp_write8,
 	.esp_read8		= zorro_esp_read8,
-	.map_single		= zorro_esp_map_single,
-	.map_sg			= zorro_esp_map_sg,
-	.unmap_single		= zorro_esp_unmap_single,
-	.unmap_sg		= zorro_esp_unmap_sg,
 	.irq_pending		= fastlane_esp_irq_pending,
 	.dma_length_limit	= zorro_esp_dma_length_limit,
 	.reset_dma		= zorro_esp_reset_dma,