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authorNadav Amit <nadav.amit@gmail.com>2010-04-08 23:00:41 +0300
committerDavid Woodhouse <David.Woodhouse@intel.com>2010-04-09 15:54:41 +0100
commit78d5f0f500e6ba8f6cfd0673475ff4d941d705a2 (patch)
treed992607aba2b178a251d52d4e2ac6f9c62709c10
parent82653633b6161cdecc011d15bc9df1c7489bd9a2 (diff)
intel-iommu: Avoid global flushes with caching mode.
While it may be efficient on real hardware, emulation of global invalidations is very expensive as all shadow entries must be examined. This patch changes the behaviour when caching mode is enabled (which is the case when IOMMU emulation takes place). In this case, page specific invalidation is used instead. Signed-off-by: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
-rw-r--r--drivers/pci/intel-iommu.c19
1 files changed, 14 insertions, 5 deletions
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 1880ee06d70..9ce79b1bae8 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -2647,15 +2647,24 @@ static void flush_unmaps(void)
if (!deferred_flush[i].next)
continue;
- iommu->flush.flush_iotlb(iommu, 0, 0, 0,
+ /* In caching mode, global flushes turn emulation expensive */
+ if (!cap_caching_mode(iommu->cap))
+ iommu->flush.flush_iotlb(iommu, 0, 0, 0,
DMA_TLB_GLOBAL_FLUSH);
for (j = 0; j < deferred_flush[i].next; j++) {
unsigned long mask;
struct iova *iova = deferred_flush[i].iova[j];
-
- mask = ilog2(mm_to_dma_pfn(iova->pfn_hi - iova->pfn_lo + 1));
- iommu_flush_dev_iotlb(deferred_flush[i].domain[j],
- (uint64_t)iova->pfn_lo << PAGE_SHIFT, mask);
+ struct dmar_domain *domain = deferred_flush[i].domain[j];
+
+ /* On real hardware multiple invalidations are expensive */
+ if (cap_caching_mode(iommu->cap))
+ iommu_flush_iotlb_psi(iommu, domain->id,
+ iova->pfn_lo, iova->pfn_hi - iova->pfn_lo + 1, 0);
+ else {
+ mask = ilog2(mm_to_dma_pfn(iova->pfn_hi - iova->pfn_lo + 1));
+ iommu_flush_dev_iotlb(deferred_flush[i].domain[j],
+ (uint64_t)iova->pfn_lo << PAGE_SHIFT, mask);
+ }
__free_iova(&deferred_flush[i].domain[j]->iovad, iova);
}
deferred_flush[i].next = 0;