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-rw-r--r--arch/powerpc/kernel/iommu.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index 95edad4faf2..c50d7072f30 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -76,6 +76,7 @@ static unsigned long iommu_range_alloc(struct iommu_table *tbl,
unsigned int align_order)
{
unsigned long n, end, i, start;
+ unsigned long start_addr, end_addr;
unsigned long limit;
int largealloc = npages > 15;
int pass = 0;
@@ -146,6 +147,15 @@ static unsigned long iommu_range_alloc(struct iommu_table *tbl,
}
}
+ /* DMA cannot cross 4 GB boundary */
+ start_addr = (n + tbl->it_offset) << PAGE_SHIFT;
+ end_addr = (end + tbl->it_offset) << PAGE_SHIFT;
+ if ((start_addr >> 32) != (end_addr >> 32)) {
+ end_addr &= 0xffffffff00000000l;
+ start = (end_addr >> PAGE_SHIFT) - tbl->it_offset;
+ goto again;
+ }
+
for (i = n; i < end; i++)
if (test_bit(i, tbl->it_map)) {
start = i+1;