Fix the calculation of the end address when flushing iotlb entries to
ram. This bug has been a cause of esp dma errors, and it affects
HyperSPARC systems much worse than SuperSPARC systems.
Signed-off-by: Bob Breuer <breuerr@xxxxxx>
---
Just in case it's not obvious from the patch as to how the dma was
broken: Each dma mapping sets up iopte entries for the iommu, and the
iommu only looks in main memory for the iopte entries. If there is a
group of iopte entries that are smaller than a page in size, but
straddle a page boundary, the broken code would fail to flush the last
page to ram.
Bob
diff --git a/arch/sparc/mm/iommu.c b/arch/sparc/mm/iommu.c
index 77840c8..7215849 100644
--- a/arch/sparc/mm/iommu.c
+++ b/arch/sparc/mm/iommu.c
@@ -144,8 +144,9 @@ static void iommu_flush_iotlb(iopte_t *i
unsigned long start;
unsigned long end;
- start = (unsigned long)iopte & PAGE_MASK;
+ start = (unsigned long)iopte;
end = PAGE_ALIGN(start + niopte*sizeof(iopte_t));
+ start &= PAGE_MASK;
if (viking_mxcc_present) {
while(start < end) {
viking_mxcc_flush_page(start);
