iommu/vt-d: Fix SVM IOTLB flush handling

Change the 'pages' parameter to 'unsigned long' to avoid overflow.

Fix the device-IOTLB flush parameter calculation — the size of the IOTLB
flush is indicated by the position of the least significant zero bit in
the address field. For example, a value of 0x12345f000 will flush from
0x123440000 to 0x12347ffff (256KiB).

Finally, the cap_pgsel_inv() is not relevant to SVM; the spec says that
*all* implementations must support page-selective invaliation for
"first-level" translations. So don't check for it.

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

diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index dd871d5888c73636379724be398a864fd471edb6..a584df0767e690b38868ff0c114e3f0c610fa3df 100644 (file)
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -147,13 +147,11 @@ int intel_svm_finish_prq(struct intel_iommu *iommu)
 }
 
 static void intel_flush_svm_range_dev (struct intel_svm *svm, struct intel_svm_dev *sdev,
-                                      unsigned long address, int pages, int ih, int gl)
+                                      unsigned long address, unsigned long pages, int ih, int gl)
 {
        struct qi_desc desc;
-       int mask = ilog2(__roundup_pow_of_two(pages));
 
-       if (pages == -1 || !cap_pgsel_inv(svm->iommu->cap) ||
-           mask > cap_max_amask_val(svm->iommu->cap)) {
+       if (pages == -1) {
                /* For global kernel pages we have to flush them in *all* PASIDs
                 * because that's the only option the hardware gives us. Despite
                 * the fact that they are actually only accessible through one. */
@@ -165,31 +163,28 @@ static void intel_flush_svm_range_dev (struct intel_svm *svm, struct intel_svm_d
                                QI_EIOTLB_GRAN(QI_GRAN_NONG_PASID) | QI_EIOTLB_TYPE;
                desc.high = 0;
        } else {
+               int mask = ilog2(__roundup_pow_of_two(pages));
+
                desc.low = QI_EIOTLB_PASID(svm->pasid) | QI_EIOTLB_DID(sdev->did) |
                        QI_EIOTLB_GRAN(QI_GRAN_PSI_PASID) | QI_EIOTLB_TYPE;
                desc.high = QI_EIOTLB_ADDR(address) | QI_EIOTLB_GL(gl) |
                        QI_EIOTLB_IH(ih) | QI_EIOTLB_AM(mask);
        }
-
        qi_submit_sync(&desc, svm->iommu);
 
        if (sdev->dev_iotlb) {
                desc.low = QI_DEV_EIOTLB_PASID(svm->pasid) | QI_DEV_EIOTLB_SID(sdev->sid) |
                        QI_DEV_EIOTLB_QDEP(sdev->qdep) | QI_DEIOTLB_TYPE;
-               if (mask) {
-                       unsigned long adr, delta;
-
-                       /* Least significant zero bits in the address indicate the
-                        * range of the request. So mask them out according to the
-                        * size. */
-                       adr = address & ((1<<(VTD_PAGE_SHIFT + mask)) - 1);
-
-                       /* Now ensure that we round down further if the original
-                        * request was not aligned w.r.t. its size */
-                       delta = address - adr;
-                       if (delta + (pages << VTD_PAGE_SHIFT) >= (1 << (VTD_PAGE_SHIFT + mask)))
-                               adr &= ~(1 << (VTD_PAGE_SHIFT + mask));
-                       desc.high = QI_DEV_EIOTLB_ADDR(adr) | QI_DEV_EIOTLB_SIZE;
+               if (pages == -1) {
+                       desc.high = QI_DEV_EIOTLB_ADDR(-1ULL >> 1) | QI_DEV_EIOTLB_SIZE;
+               } else if (pages > 1) {
+                       /* The least significant zero bit indicates the size. So,
+                        * for example, an "address" value of 0x12345f000 will
+                        * flush from 0x123440000 to 0x12347ffff (256KiB). */
+                       unsigned long last = address + ((unsigned long)(pages - 1) << VTD_PAGE_SHIFT);
+                       unsigned long mask = __rounddown_pow_of_two(address ^ last);;
+
+                       desc.high = QI_DEV_EIOTLB_ADDR((address & ~mask) | (mask - 1)) | QI_DEV_EIOTLB_SIZE;
                } else {
                        desc.high = QI_DEV_EIOTLB_ADDR(address);
                }
@@ -198,7 +193,7 @@ static void intel_flush_svm_range_dev (struct intel_svm *svm, struct intel_svm_d
 }
 
 static void intel_flush_svm_range(struct intel_svm *svm, unsigned long address,
-                                 int pages, int ih, int gl)
+                                 unsigned long pages, int ih, int gl)
 {
        struct intel_svm_dev *sdev;