[PATCH 07/13] powerpc/powernv: Do not set "read" flag if direction==DMA_NONE
From: Alexey Kardashevskiy <hidden>
Date: 2014-08-29 08:01:56
Also in:
kvm, linuxppc-dev, lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
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 <redacted> --- 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