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authorLinus Torvalds <torvalds@linux-foundation.org>2015-10-21 23:32:48 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2015-10-21 23:32:48 +0200
commit8a70dd2669200ce83255ed8c5ebef7e59f9e8707 (patch)
tree7bcac17bcd7004c54f762a018e6dc749ea79b28c /drivers/iommu/intel-iommu.c
parentMerge tag 'mmc-v4.3-rc5' of git://git.linaro.org/people/ulf.hansson/mmc (diff)
parentiommu/vt-d: fix range computation when making room for large pages (diff)
downloadlinux-8a70dd2669200ce83255ed8c5ebef7e59f9e8707.tar.xz
linux-8a70dd2669200ce83255ed8c5ebef7e59f9e8707.zip
Merge tag 'for-linus-20151021' of git://git.infradead.org/intel-iommu
Pull intel-iommu bugfix from David Woodhouse: "This contains a single fix, for when the IOMMU API is used to overlay an existing mapping comprised of 4KiB pages, with a mapping that can use superpages. For the *first* superpage in the new mapping, we were correctly¹ freeing the old bottom-level page table page and clearing the link to it, before installing the superpage. For subsequent superpages, however, we weren't. This causes a memory leak, and a warning about setting a PTE which is already set. ¹ Well, not *entirely* correctly. We just free the page table pages right there and then, which is wrong. In fact they should only be freed *after* the IOTLB is flushed so we know the hardware will no longer be looking at them.... and in fact I note that the IOTLB flush is completely missing from the intel_iommu_map() code path, although it needs to be there if it's permitted to overwrite existing mappings. Fixing those is somewhat more intrusive though, and will probably need to wait for 4.4 at this point" * tag 'for-linus-20151021' of git://git.infradead.org/intel-iommu: iommu/vt-d: fix range computation when making room for large pages
Diffstat (limited to 'drivers/iommu/intel-iommu.c')
-rw-r--r--drivers/iommu/intel-iommu.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 35365f046923..d65cf42399e8 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -2115,15 +2115,19 @@ static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
return -ENOMEM;
/* It is large page*/
if (largepage_lvl > 1) {
+ unsigned long nr_superpages, end_pfn;
+
pteval |= DMA_PTE_LARGE_PAGE;
lvl_pages = lvl_to_nr_pages(largepage_lvl);
+
+ nr_superpages = sg_res / lvl_pages;
+ end_pfn = iov_pfn + nr_superpages * lvl_pages - 1;
+
/*
* Ensure that old small page tables are
- * removed to make room for superpage,
- * if they exist.
+ * removed to make room for superpage(s).
*/
- dma_pte_free_pagetable(domain, iov_pfn,
- iov_pfn + lvl_pages - 1);
+ dma_pte_free_pagetable(domain, iov_pfn, end_pfn);
} else {
pteval &= ~(uint64_t)DMA_PTE_LARGE_PAGE;
}