53c700: improve non-coherent DMA handling

Switch the 53c700 driver to only use non-coherent descriptor memory if it
really has to because dma_alloc_coherent fails.  This doesn't matter for
any of the platforms it runs on currently, but that will change soon.

To help with this two new helpers to transfer ownership to and from the
device are added that abstract the syncing of the non-coherent memory.
The two current bidirectional cases are mapped to transfers to the
device, as that appears to what they are used for.  Note that for parisc,
which is the only architecture this driver needs to use non-coherent
memory on, the direction argument of dma_cache_sync is ignored, so this
will not change behavior in any way.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

1 files changed, 63 insertions, 50 deletions

diff --git a/drivers/scsi/53c700.c b/drivers/scsi/53c700.c
index 84b57a8f86bf..c59226d7e2f6 100644
--- a/drivers/scsi/53c700.c
+++ b/drivers/scsi/53c700.c
@@ -269,6 +269,20 @@ NCR_700_get_SXFER(struct scsi_device *SDp)
 					      spi_period(SDp->sdev_target));
 }
 
+static inline void dma_sync_to_dev(struct NCR_700_Host_Parameters *h,
+		void *addr, size_t size)
+{
+	if (h->noncoherent)
+		dma_cache_sync(h->dev, addr, size, DMA_TO_DEVICE);
+}
+
+static inline void dma_sync_from_dev(struct NCR_700_Host_Parameters *h,
+		void *addr, size_t size)
+{
+	if (h->noncoherent)
+		dma_cache_sync(h->dev, addr, size, DMA_FROM_DEVICE);
+}
+
 struct Scsi_Host *
 NCR_700_detect(struct scsi_host_template *tpnt,
 	       struct NCR_700_Host_Parameters *hostdata, struct device *dev)
@@ -283,9 +297,13 @@ NCR_700_detect(struct scsi_host_template *tpnt,
 	if(tpnt->sdev_attrs == NULL)
 		tpnt->sdev_attrs = NCR_700_dev_attrs;
 
-	memory = dma_alloc_attrs(dev, TOTAL_MEM_SIZE, &pScript,
-				 GFP_KERNEL, DMA_ATTR_NON_CONSISTENT);
-	if(memory == NULL) {
+	memory = dma_alloc_coherent(dev, TOTAL_MEM_SIZE, &pScript, GFP_KERNEL);
+	if (!memory) {
+		hostdata->noncoherent = 1;
+		memory = dma_alloc_attrs(dev, TOTAL_MEM_SIZE, &pScript,
+					 GFP_KERNEL, DMA_ATTR_NON_CONSISTENT);
+	}
+	if (!memory) {
 		printk(KERN_ERR "53c700: Failed to allocate memory for driver, detaching\n");
 		return NULL;
 	}
@@ -339,11 +357,11 @@ NCR_700_detect(struct scsi_host_template *tpnt,
 	for (j = 0; j < PATCHES; j++)
 		script[LABELPATCHES[j]] = bS_to_host(pScript + SCRIPT[LABELPATCHES[j]]);
 	/* now patch up fixed addresses. */
-	script_patch_32(hostdata->dev, script, MessageLocation,
+	script_patch_32(hostdata, script, MessageLocation,
 			pScript + MSGOUT_OFFSET);
-	script_patch_32(hostdata->dev, script, StatusAddress,
+	script_patch_32(hostdata, script, StatusAddress,
 			pScript + STATUS_OFFSET);
-	script_patch_32(hostdata->dev, script, ReceiveMsgAddress,
+	script_patch_32(hostdata, script, ReceiveMsgAddress,
 			pScript + MSGIN_OFFSET);
 
 	hostdata->script = script;
@@ -395,8 +413,12 @@ NCR_700_release(struct Scsi_Host *host)
 	struct NCR_700_Host_Parameters *hostdata = 
 		(struct NCR_700_Host_Parameters *)host->hostdata[0];
 
-	dma_free_attrs(hostdata->dev, TOTAL_MEM_SIZE, hostdata->script,
-		       hostdata->pScript, DMA_ATTR_NON_CONSISTENT);
+	if (hostdata->noncoherent)
+		dma_free_attrs(hostdata->dev, TOTAL_MEM_SIZE, hostdata->script,
+			       hostdata->pScript, DMA_ATTR_NON_CONSISTENT);
+	else
+		dma_free_coherent(hostdata->dev, TOTAL_MEM_SIZE,
+				  hostdata->script, hostdata->pScript);
 	return 1;
 }
 
@@ -804,8 +826,8 @@ process_extended_message(struct Scsi_Host *host,
 			shost_printk(KERN_WARNING, host,
 				"Unexpected SDTR msg\n");
 			hostdata->msgout[0] = A_REJECT_MSG;
-			dma_cache_sync(hostdata->dev, hostdata->msgout, 1, DMA_TO_DEVICE);
-			script_patch_16(hostdata->dev, hostdata->script,
+			dma_sync_to_dev(hostdata, hostdata->msgout, 1);
+			script_patch_16(hostdata, hostdata->script,
 			                MessageCount, 1);
 			/* SendMsgOut returns, so set up the return
 			 * address */
@@ -817,9 +839,8 @@ process_extended_message(struct Scsi_Host *host,
 		printk(KERN_INFO "scsi%d: (%d:%d), Unsolicited WDTR after CMD, Rejecting\n",
 		       host->host_no, pun, lun);
 		hostdata->msgout[0] = A_REJECT_MSG;
-		dma_cache_sync(hostdata->dev, hostdata->msgout, 1, DMA_TO_DEVICE);
-		script_patch_16(hostdata->dev, hostdata->script, MessageCount,
-		                1);
+		dma_sync_to_dev(hostdata, hostdata->msgout, 1);
+		script_patch_16(hostdata, hostdata->script, MessageCount, 1);
 		resume_offset = hostdata->pScript + Ent_SendMessageWithATN;
 
 		break;
@@ -832,9 +853,8 @@ process_extended_message(struct Scsi_Host *host,
 		printk("\n");
 		/* just reject it */
 		hostdata->msgout[0] = A_REJECT_MSG;
-		dma_cache_sync(hostdata->dev, hostdata->msgout, 1, DMA_TO_DEVICE);
-		script_patch_16(hostdata->dev, hostdata->script, MessageCount,
-		                1);
+		dma_sync_to_dev(hostdata, hostdata->msgout, 1);
+		script_patch_16(hostdata, hostdata->script, MessageCount, 1);
 		/* SendMsgOut returns, so set up the return
 		 * address */
 		resume_offset = hostdata->pScript + Ent_SendMessageWithATN;
@@ -917,9 +937,8 @@ process_message(struct Scsi_Host *host,	struct NCR_700_Host_Parameters *hostdata
 		printk("\n");
 		/* just reject it */
 		hostdata->msgout[0] = A_REJECT_MSG;
-		dma_cache_sync(hostdata->dev, hostdata->msgout, 1, DMA_TO_DEVICE);
-		script_patch_16(hostdata->dev, hostdata->script, MessageCount,
-		                1);
+		dma_sync_to_dev(hostdata, hostdata->msgout, 1);
+		script_patch_16(hostdata, hostdata->script, MessageCount, 1);
 		/* SendMsgOut returns, so set up the return
 		 * address */
 		resume_offset = hostdata->pScript + Ent_SendMessageWithATN;
@@ -928,7 +947,7 @@ process_message(struct Scsi_Host *host,	struct NCR_700_Host_Parameters *hostdata
 	}
 	NCR_700_writel(temp, host, TEMP_REG);
 	/* set us up to receive another message */
-	dma_cache_sync(hostdata->dev, hostdata->msgin, MSG_ARRAY_SIZE, DMA_FROM_DEVICE);
+	dma_sync_from_dev(hostdata, hostdata->msgin, MSG_ARRAY_SIZE);
 	return resume_offset;
 }
 
@@ -1008,8 +1027,8 @@ process_script_interrupt(__u32 dsps, __u32 dsp, struct scsi_cmnd *SCp,
 				slot->SG[1].ins = bS_to_host(SCRIPT_RETURN);
 				slot->SG[1].pAddr = 0;
 				slot->resume_offset = hostdata->pScript;
-				dma_cache_sync(hostdata->dev, slot->SG, sizeof(slot->SG[0])*2, DMA_TO_DEVICE);
-				dma_cache_sync(hostdata->dev, SCp->sense_buffer, SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
+				dma_sync_to_dev(hostdata, slot->SG, sizeof(slot->SG[0])*2);
+				dma_sync_from_dev(hostdata, SCp->sense_buffer, SCSI_SENSE_BUFFERSIZE);
 
 				/* queue the command for reissue */
 				slot->state = NCR_700_SLOT_QUEUED;
@@ -1129,11 +1148,11 @@ process_script_interrupt(__u32 dsps, __u32 dsp, struct scsi_cmnd *SCp,
 			hostdata->cmd = slot->cmnd;
 
 			/* re-patch for this command */
-			script_patch_32_abs(hostdata->dev, hostdata->script,
+			script_patch_32_abs(hostdata, hostdata->script,
 			                    CommandAddress, slot->pCmd);
-			script_patch_16(hostdata->dev, hostdata->script,
+			script_patch_16(hostdata, hostdata->script,
 					CommandCount, slot->cmnd->cmd_len);
-			script_patch_32_abs(hostdata->dev, hostdata->script,
+			script_patch_32_abs(hostdata, hostdata->script,
 			                    SGScriptStartAddress,
 					    to32bit(&slot->pSG[0].ins));
 
@@ -1144,14 +1163,14 @@ process_script_interrupt(__u32 dsps, __u32 dsp, struct scsi_cmnd *SCp,
 			 * should therefore always clear ACK */
 			NCR_700_writeb(NCR_700_get_SXFER(hostdata->cmd->device),
 				       host, SXFER_REG);
-			dma_cache_sync(hostdata->dev, hostdata->msgin,
-				       MSG_ARRAY_SIZE, DMA_FROM_DEVICE);
-			dma_cache_sync(hostdata->dev, hostdata->msgout,
-				       MSG_ARRAY_SIZE, DMA_TO_DEVICE);
+			dma_sync_from_dev(hostdata, hostdata->msgin,
+				       MSG_ARRAY_SIZE);
+			dma_sync_to_dev(hostdata, hostdata->msgout,
+				       MSG_ARRAY_SIZE);
 			/* I'm just being paranoid here, the command should
 			 * already have been flushed from the cache */
-			dma_cache_sync(hostdata->dev, slot->cmnd->cmnd,
-				       slot->cmnd->cmd_len, DMA_TO_DEVICE);
+			dma_sync_to_dev(hostdata, slot->cmnd->cmnd,
+				       slot->cmnd->cmd_len);
 
 
 			
@@ -1214,8 +1233,7 @@ process_script_interrupt(__u32 dsps, __u32 dsp, struct scsi_cmnd *SCp,
 		hostdata->reselection_id = reselection_id;
 		/* just in case we have a stale simple tag message, clear it */
 		hostdata->msgin[1] = 0;
-		dma_cache_sync(hostdata->dev, hostdata->msgin,
-			       MSG_ARRAY_SIZE, DMA_BIDIRECTIONAL);
+		dma_sync_to_dev(hostdata, hostdata->msgin, MSG_ARRAY_SIZE);
 		if(hostdata->tag_negotiated & (1<<reselection_id)) {
 			resume_offset = hostdata->pScript + Ent_GetReselectionWithTag;
 		} else {
@@ -1329,8 +1347,7 @@ process_selection(struct Scsi_Host *host, __u32 dsp)
 	hostdata->cmd = NULL;
 	/* clear any stale simple tag message */
 	hostdata->msgin[1] = 0;
-	dma_cache_sync(hostdata->dev, hostdata->msgin, MSG_ARRAY_SIZE,
-		       DMA_BIDIRECTIONAL);
+	dma_sync_to_dev(hostdata, hostdata->msgin, MSG_ARRAY_SIZE);
 
 	if(id == 0xff) {
 		/* Selected as target, Ignore */
@@ -1427,30 +1444,26 @@ NCR_700_start_command(struct scsi_cmnd *SCp)
 		NCR_700_set_flag(SCp->device, NCR_700_DEV_BEGIN_SYNC_NEGOTIATION);
 	}
 
-	script_patch_16(hostdata->dev, hostdata->script, MessageCount, count);
-
+	script_patch_16(hostdata, hostdata->script, MessageCount, count);
 
-	script_patch_ID(hostdata->dev, hostdata->script,
-			Device_ID, 1<<scmd_id(SCp));
+	script_patch_ID(hostdata, hostdata->script, Device_ID, 1<<scmd_id(SCp));
 
-	script_patch_32_abs(hostdata->dev, hostdata->script, CommandAddress,
+	script_patch_32_abs(hostdata, hostdata->script, CommandAddress,
 			    slot->pCmd);
-	script_patch_16(hostdata->dev, hostdata->script, CommandCount,
-	                SCp->cmd_len);
+	script_patch_16(hostdata, hostdata->script, CommandCount, SCp->cmd_len);
 	/* finally plumb the beginning of the SG list into the script
 	 * */
-	script_patch_32_abs(hostdata->dev, hostdata->script,
+	script_patch_32_abs(hostdata, hostdata->script,
 	                    SGScriptStartAddress, to32bit(&slot->pSG[0].ins));
 	NCR_700_clear_fifo(SCp->device->host);
 
 	if(slot->resume_offset == 0)
 		slot->resume_offset = hostdata->pScript;
 	/* now perform all the writebacks and invalidates */
-	dma_cache_sync(hostdata->dev, hostdata->msgout, count, DMA_TO_DEVICE);
-	dma_cache_sync(hostdata->dev, hostdata->msgin, MSG_ARRAY_SIZE,
-		       DMA_FROM_DEVICE);
-	dma_cache_sync(hostdata->dev, SCp->cmnd, SCp->cmd_len, DMA_TO_DEVICE);
-	dma_cache_sync(hostdata->dev, hostdata->status, 1, DMA_FROM_DEVICE);
+	dma_sync_to_dev(hostdata, hostdata->msgout, count);
+	dma_sync_from_dev(hostdata, hostdata->msgin, MSG_ARRAY_SIZE);
+	dma_sync_to_dev(hostdata, SCp->cmnd, SCp->cmd_len);
+	dma_sync_from_dev(hostdata, hostdata->status, 1);
 
 	/* set the synchronous period/offset */
 	NCR_700_writeb(NCR_700_get_SXFER(SCp->device),
@@ -1626,7 +1639,7 @@ NCR_700_intr(int irq, void *dev_id)
 					slot->SG[i].ins = bS_to_host(SCRIPT_NOP);
 					slot->SG[i].pAddr = 0;
 				}
-				dma_cache_sync(hostdata->dev, slot->SG, sizeof(slot->SG), DMA_TO_DEVICE);
+				dma_sync_to_dev(hostdata, slot->SG, sizeof(slot->SG));
 				/* and pretend we disconnected after
 				 * the command phase */
 				resume_offset = hostdata->pScript + Ent_MsgInDuringData;
@@ -1878,7 +1891,7 @@ NCR_700_queuecommand_lck(struct scsi_cmnd *SCp, void (*done)(struct scsi_cmnd *)
 		}
 		slot->SG[i].ins = bS_to_host(SCRIPT_RETURN);
 		slot->SG[i].pAddr = 0;
-		dma_cache_sync(hostdata->dev, slot->SG, sizeof(slot->SG), DMA_TO_DEVICE);
+		dma_sync_to_dev(hostdata, slot->SG, sizeof(slot->SG));
 		DEBUG((" SETTING %p to %x\n",
 		       (&slot->pSG[i].ins),
 		       slot->SG[i].ins));