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>

drivers/scsi/53c700.h

@@ -209,6 +209,7 @@ struct NCR_700_Host_Parameters {
 #endif
 	__u32	chip710:1;	/* set if really a 710 not 700 */
 	__u32	burst_length:4;	/* set to 0 to disable 710 bursting */
+	__u32	noncoherent:1;	/* needs to use non-coherent DMA */
 
 	/* NOTHING BELOW HERE NEEDS ALTERING */
 	__u32	fast:1;		/* if we can alter the SCSI bus clock
@@ -422,33 +423,33 @@ struct NCR_700_Host_Parameters {
 #define NCR_710_MIN_XFERP	0
 #define NCR_700_MIN_PERIOD	25 /* for SDTR message, 100ns */
 
-#define script_patch_32(dev, script, symbol, value) \
+#define script_patch_32(h, script, symbol, value) \
 { \
 	int i; \
 	dma_addr_t da = value; \
 	for(i=0; i< (sizeof(A_##symbol##_used) / sizeof(__u32)); i++) { \
 		__u32 val = bS_to_cpu((script)[A_##symbol##_used[i]]) + da; \
 		(script)[A_##symbol##_used[i]] = bS_to_host(val); \
-		dma_cache_sync((dev), &(script)[A_##symbol##_used[i]], 4, DMA_TO_DEVICE); \
+		dma_sync_to_dev((h), &(script)[A_##symbol##_used[i]], 4); \
 		DEBUG((" script, patching %s at %d to %pad\n", \
 		       #symbol, A_##symbol##_used[i], &da)); \
 	} \
 }
 
-#define script_patch_32_abs(dev, script, symbol, value) \
+#define script_patch_32_abs(h, script, symbol, value) \
 { \
 	int i; \
 	dma_addr_t da = value; \
 	for(i=0; i< (sizeof(A_##symbol##_used) / sizeof(__u32)); i++) { \
 		(script)[A_##symbol##_used[i]] = bS_to_host(da); \
-		dma_cache_sync((dev), &(script)[A_##symbol##_used[i]], 4, DMA_TO_DEVICE); \
+		dma_sync_to_dev((h), &(script)[A_##symbol##_used[i]], 4); \
 		DEBUG((" script, patching %s at %d to %pad\n", \
 		       #symbol, A_##symbol##_used[i], &da)); \
 	} \
 }
 
 /* Used for patching the SCSI ID in the SELECT instruction */
-#define script_patch_ID(dev, script, symbol, value) \
+#define script_patch_ID(h, script, symbol, value) \
 { \
 	int i; \
 	for(i=0; i< (sizeof(A_##symbol##_used) / sizeof(__u32)); i++) { \
@@ -456,13 +457,13 @@ struct NCR_700_Host_Parameters {
 		val &= 0xff00ffff; \
 		val |= ((value) & 0xff) << 16; \
 		(script)[A_##symbol##_used[i]] = bS_to_host(val); \
-		dma_cache_sync((dev), &(script)[A_##symbol##_used[i]], 4, DMA_TO_DEVICE); \
+		dma_sync_to_dev((h), &(script)[A_##symbol##_used[i]], 4); \
 		DEBUG((" script, patching ID field %s at %d to 0x%x\n", \
 		       #symbol, A_##symbol##_used[i], val)); \
 	} \
 }
 
-#define script_patch_16(dev, script, symbol, value) \
+#define script_patch_16(h, script, symbol, value) \
 { \
 	int i; \
 	for(i=0; i< (sizeof(A_##symbol##_used) / sizeof(__u32)); i++) { \
@@ -470,7 +471,7 @@ struct NCR_700_Host_Parameters {
 		val &= 0xffff0000; \
 		val |= ((value) & 0xffff); \
 		(script)[A_##symbol##_used[i]] = bS_to_host(val); \
-		dma_cache_sync((dev), &(script)[A_##symbol##_used[i]], 4, DMA_TO_DEVICE); \
+		dma_sync_to_dev((h), &(script)[A_##symbol##_used[i]], 4); \
 		DEBUG((" script, patching short field %s at %d to 0x%x\n", \
 		       #symbol, A_##symbol##_used[i], val)); \
 	} \