[PATCH] x86_84 pci_map_sg fix for 2.6.0-test7

[Badari Pulavarty]

Hi,

Here is the patch to fix few minor issues with pci_map_sg() and pci_map_cont()
for x86_64. I ran into these asserts while testing with qlogic fc driver.

The patch fixes following:

1) pci_map_sg() coalsces "sg" entries without modifying command's
"use_sg" value. It sets the "sg" entries length to "0" to indicate that
these entires are coalsced. If the command gets retried, the pci_map_sg() 
code trips on the assert that all entries length should be > 0.

2) __pci_map_cont() incorrectly assumes that "start" is always 0, so it
trips on few asserts.

Thanks,
Badari



--- linux-2.6.0-test7/arch/x86_64/kernel/pci-gart.c	2003-10-10 11:48:40.324040400 -0700
+++ linux-2.6.0-test7.new/arch/x86_64/kernel/pci-gart.c	2003-10-10 11:49:12.281182176 -0700
@@ -395,7 +395,7 @@ static int __pci_map_cont(struct scatter
 	for (i = start; i < stopat; i++) {
 		struct scatterlist *s = &sg[i];
 		unsigned long start_addr = s->dma_address;
-		BUG_ON(i > 0 && s->offset);
+		BUG_ON(i > start && s->offset);
 		if (i == start) {
 			*sout = *s; 
 			sout->dma_address = iommu_bus_base;
@@ -409,8 +409,8 @@ static int __pci_map_cont(struct scatter
 			SET_LEAK(iommu_page);
 			addr += PAGE_SIZE;
 			iommu_page++;
-	} 
-		BUG_ON(i > 0 && addr % PAGE_SIZE); 
+		} 
+		BUG_ON(i > start && addr % PAGE_SIZE); 
 	} 
 	BUG_ON(iommu_page - iommu_start != pages);	
 	return 0;
@@ -451,7 +451,8 @@ int pci_map_sg(struct pci_dev *dev, stru
 		struct scatterlist *s = &sg[i];
 		dma_addr_t addr = page_to_phys(s->page) + s->offset;
 		s->dma_address = addr;
-		BUG_ON(s->length == 0); 
+		if (s->length == 0)
+			break;
 
 		size += s->length;