On 05/23/2013 08:35 PM, Li, Zhen-Hua wrote:
In Intel Vt-D specs, Chapter 9.3 Page-Table Entry,
The size of ADDR(address) field is 12:51, but the function dma_pte_addr
  treats it as 12:63.

Signed-off-by: Li, Zhen-Hua<[email protected]>
---
  drivers/iommu/intel-iommu.c   |    4 ++--
  include/linux/dma_remapping.h |    2 ++
  2 files changed, 4 insertions(+), 2 deletions(-)


Is this patching for the sake of spec interpretation?
a dma-pte format (consumed by iommu) has 63,61:52 as available for sw, ignored 
by hw.
62 is 'transient mapping' bit, which is a _hint_ for selecting iotlbs to flush 
sooner.
finally, the system would have to have a memory map that actually has bit 62 
set to
be affected.

So, for intel-iommu, I don't see a bug occurring.
Did you actually have one with previous definition, and if so,
could you provide that information ?

Cheers,
- Don
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index b4f0e28..c6d2847 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -311,10 +311,10 @@ static inline void dma_set_pte_prot(struct dma_pte *pte, 
unsigned long prot)
  static inline u64 dma_pte_addr(struct dma_pte *pte)
  {
  #ifdef CONFIG_64BIT
-       return pte->val&  VTD_PAGE_MASK;
+       return pte->val&  DMA_PTE_MASK;
  #else
        /* Must have a full atomic 64-bit read */
-       return  __cmpxchg64(&pte->val, 0ULL, 0ULL)&  VTD_PAGE_MASK;
+       return  __cmpxchg64(&pte->val, 0ULL, 0ULL)&  DMA_PTE_MASK;
  #endif
  }

diff --git a/include/linux/dma_remapping.h b/include/linux/dma_remapping.h
index 57c9a8a..7a1e212 100644
--- a/include/linux/dma_remapping.h
+++ b/include/linux/dma_remapping.h
@@ -16,6 +16,8 @@
  #define DMA_PTE_WRITE (2)
  #define DMA_PTE_LARGE_PAGE (1<<  7)
  #define DMA_PTE_SNP (1<<  11)
+#define DMA_PTE_ADD_LENGTH (40)
+#define DMA_PTE_MASK   ((((u64)1<<  DMA_PTE_ADD_LENGTH) - 1)<<  VTD_PAGE_SHIFT)

  #define CONTEXT_TT_MULTI_LEVEL        0
  #define CONTEXT_TT_DEV_IOTLB  1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to