intel-iommu: Fix dma vs. mm page confusion with aligned_nrpages()
The aligned_nrpages() function rounds up to the next VM page, but
returns its result as a number of DMA pages.
Purely theoretical except on IA64, which doesn't boot with VT-d right
now anyway.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 5307542..ad85e95 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -2368,15 +2368,15 @@
return ret;
}
+/* Returns a number of VTD pages, but aligned to MM page size */
static inline unsigned long aligned_nrpages(unsigned long host_addr,
size_t size)
{
host_addr &= ~PAGE_MASK;
- host_addr += size + PAGE_SIZE - 1;
-
- return host_addr >> VTD_PAGE_SHIFT;
+ return PAGE_ALIGN(host_addr + size) >> VTD_PAGE_SHIFT;
}
+/* This takes a number of _MM_ pages, not VTD pages */
static struct iova *intel_alloc_iova(struct device *dev,
struct dmar_domain *domain,
unsigned long nrpages, uint64_t dma_mask)
@@ -2506,7 +2506,8 @@
iommu = domain_get_iommu(domain);
size = aligned_nrpages(paddr, size);
- iova = intel_alloc_iova(hwdev, domain, size, pdev->dma_mask);
+ iova = intel_alloc_iova(hwdev, domain, dma_to_mm_pfn(size),
+ pdev->dma_mask);
if (!iova)
goto error;
@@ -2797,7 +2798,8 @@
for_each_sg(sglist, sg, nelems, i)
size += aligned_nrpages(sg->offset, sg->length);
- iova = intel_alloc_iova(hwdev, domain, size, pdev->dma_mask);
+ iova = intel_alloc_iova(hwdev, domain, dma_to_mm_pfn(size),
+ pdev->dma_mask);
if (!iova) {
sglist->dma_length = 0;
return 0;