On PowerPC, currently we support different value of PAGE_SIZE and different
value of IOMMU Page Size.
In case the PAGE_SIZE is 4K and the IOMMU Page Size is 16M, and driver
asked for some DMA less than 16M, the current calculation would return 0
and the following allocation in iommu_alloc() would fail.
This patch uses iommu_num_pages() to calculate it.
Signed-off-by: Wei Yang <weiy...@linux.vnet.ibm.com>
---
arch/powerpc/kernel/iommu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index a8e3490..9885397 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -842,7 +842,7 @@ void *iommu_alloc_coherent(struct device *dev, struct
iommu_table *tbl,
memset(ret, 0, size);
/* Set up tces to cover the allocated range */
- nio_pages = size >> tbl->it_page_shift;
+ nio_pages = iommu_num_pages(0, size, IOMMU_PAGE_SIZE(tbl));
io_order = get_iommu_order(size, tbl);
mapping = iommu_alloc(dev, tbl, ret, nio_pages, DMA_BIDIRECTIONAL,
mask >> tbl->it_page_shift, io_order, NULL);
--
2.5.0
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