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path: root/drivers/iommu/intel/iommu.c
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Diffstat (limited to 'drivers/iommu/intel/iommu.c')
-rw-r--r--drivers/iommu/intel/iommu.c27
1 files changed, 24 insertions, 3 deletions
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index df5c62ecf942..0ea47e17b379 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1588,7 +1588,8 @@ static void iommu_flush_iotlb_psi(struct intel_iommu *iommu,
unsigned long pfn, unsigned int pages,
int ih, int map)
{
- unsigned int mask = ilog2(__roundup_pow_of_two(pages));
+ unsigned int aligned_pages = __roundup_pow_of_two(pages);
+ unsigned int mask = ilog2(aligned_pages);
uint64_t addr = (uint64_t)pfn << VTD_PAGE_SHIFT;
u16 did = domain->iommu_did[iommu->seq_id];
@@ -1600,10 +1601,30 @@ static void iommu_flush_iotlb_psi(struct intel_iommu *iommu,
if (domain_use_first_level(domain)) {
qi_flush_piotlb(iommu, did, PASID_RID2PASID, addr, pages, ih);
} else {
+ unsigned long bitmask = aligned_pages - 1;
+
+ /*
+ * PSI masks the low order bits of the base address. If the
+ * address isn't aligned to the mask, then compute a mask value
+ * needed to ensure the target range is flushed.
+ */
+ if (unlikely(bitmask & pfn)) {
+ unsigned long end_pfn = pfn + pages - 1, shared_bits;
+
+ /*
+ * Since end_pfn <= pfn + bitmask, the only way bits
+ * higher than bitmask can differ in pfn and end_pfn is
+ * by carrying. This means after masking out bitmask,
+ * high bits starting with the first set bit in
+ * shared_bits are all equal in both pfn and end_pfn.
+ */
+ shared_bits = ~(pfn ^ end_pfn) & ~bitmask;
+ mask = shared_bits ? __ffs(shared_bits) : BITS_PER_LONG;
+ }
+
/*
* Fallback to domain selective flush if no PSI support or
- * the size is too big. PSI requires page size to be 2 ^ x,
- * and the base address is naturally aligned to the size.
+ * the size is too big.
*/
if (!cap_pgsel_inv(iommu->cap) ||
mask > cap_max_amask_val(iommu->cap))