[PATCH 07/13] powerpc/powernv: Do not set "read" flag if direction==DMA_NONE

[Alexey Kardashevskiy]

Normally a bitmap from the iommu_table is used to track what TCE entry
is in use. Since we are going to use iommu_table without its locks and
do xchg() instead, it becomes essential not to put bits which are not
implied in the direction flag.

Signed-off-by: Alexey Kardashevskiy 
---
 arch/powerpc/platforms/powernv/pci.c | 16 
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/pci.c 
b/arch/powerpc/platforms/powernv/pci.c
index deddcad..ab79e2d 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -628,10 +628,18 @@ static int pnv_tce_build(struct iommu_table *tbl, long 
index, long npages,
__be64 *tcep, *tces;
u64 rpn;
 
-   proto_tce = TCE_PCI_READ; // Read allowed
-
-   if (direction != DMA_TO_DEVICE)
-   proto_tce |= TCE_PCI_WRITE;
+   switch (direction) {
+   case DMA_BIDIRECTIONAL:
+   case DMA_FROM_DEVICE:
+   proto_tce = TCE_PCI_READ | TCE_PCI_WRITE;
+   break;
+   case DMA_TO_DEVICE:
+   proto_tce = TCE_PCI_READ;
+   break;
+   default:
+   proto_tce = 0;
+   break;
+   }
 
tces = tcep = ((__be64 *)tbl->it_base) + index - tbl->it_offset;
rpn = __pa(uaddr) >> tbl->it_page_shift;
-- 
2.0.0

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[PATCH 07/13] powerpc/powernv: Do not set read flag if direction==DMA_NONE

[Alexey Kardashevskiy]

Normally a bitmap from the iommu_table is used to track what TCE entry
is in use. Since we are going to use iommu_table without its locks and
do xchg() instead, it becomes essential not to put bits which are not
implied in the direction flag.

Signed-off-by: Alexey Kardashevskiy a...@ozlabs.ru
---
 arch/powerpc/platforms/powernv/pci.c | 16 
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/pci.c 
b/arch/powerpc/platforms/powernv/pci.c
index deddcad..ab79e2d 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -628,10 +628,18 @@ static int pnv_tce_build(struct iommu_table *tbl, long 
index, long npages,
__be64 *tcep, *tces;
u64 rpn;
 
-   proto_tce = TCE_PCI_READ; // Read allowed
-
-   if (direction != DMA_TO_DEVICE)
-   proto_tce |= TCE_PCI_WRITE;
+   switch (direction) {
+   case DMA_BIDIRECTIONAL:
+   case DMA_FROM_DEVICE:
+   proto_tce = TCE_PCI_READ | TCE_PCI_WRITE;
+   break;
+   case DMA_TO_DEVICE:
+   proto_tce = TCE_PCI_READ;
+   break;
+   default:
+   proto_tce = 0;
+   break;
+   }
 
tces = tcep = ((__be64 *)tbl-it_base) + index - tbl-it_offset;
rpn = __pa(uaddr)  tbl-it_page_shift;
-- 
2.0.0

--
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Please read the FAQ at  http://www.tux.org/lkml/