iommu/vt-d: Implement deferred invalidate for SVM

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

3 files changed, 12 insertions, 0 deletions

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 60b66d27e655..58ecd52af43b 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4981,6 +4981,8 @@ int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct intel_svm_dev *sd
                                 ctx_lo |= CONTEXT_TT_PT_PASID << 2;
                 }
                 ctx_lo |= CONTEXT_PASIDE;
+                if (iommu->pasid_state_table)
+                        ctx_lo |= CONTEXT_DINVE;
                 context[0].lo = ctx_lo;
                 wmb();
                 iommu->flush.flush_context(iommu, sdev->did, sdev->sid,
diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index 82d53e15b865..a64720b5bd34 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -26,6 +26,10 @@ struct pasid_entry {
         u64 val;
 };
 
+struct pasid_state_entry {
+        u64 val;
+};
+
 int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu)
 {
         struct page *pages;
@@ -127,6 +131,11 @@ static void intel_flush_svm_range(struct intel_svm *svm, unsigned long address,
 {
         struct intel_svm_dev *sdev;
 
+        /* Try deferred invalidate if available */
+        if (svm->iommu->pasid_state_table &&
+            !cmpxchg64(&svm->iommu->pasid_state_table[svm->pasid].val, 0, 1ULL << 63))
+                return;
+
         rcu_read_lock();
         list_for_each_entry_rcu(sdev, &svm->devs, list)
                 intel_flush_svm_range_dev(svm, sdev, address, pages, ih);
diff --git a/include/linux/dma_remapping.h b/include/linux/dma_remapping.h
index 0e114bfabeed..187c10299722 100644
--- a/include/linux/dma_remapping.h
+++ b/include/linux/dma_remapping.h
@@ -25,6 +25,7 @@
 #define CONTEXT_TT_PT_PASID_DEV_IOTLB 5
 #define CONTEXT_TT_MASK (7ULL << 2)
 
+#define CONTEXT_DINVE           (1ULL << 8)
 #define CONTEXT_PRS             (1ULL << 9)
 #define CONTEXT_PASIDE          (1ULL << 11)