Upgrade to 4.4.50-rt62

[kvmfornfv.git] / kernel / drivers / iommu / intel-svm.c

diff --git a/kernel/drivers/iommu/intel-svm.c b/kernel/drivers/iommu/intel-svm.c
index d9939fa..f929879 100644 (file)
--- a/kernel/drivers/iommu/intel-svm.c
+++ b/kernel/drivers/iommu/intel-svm.c
@@ -39,10 +39,18 @@ int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu)
        struct page *pages;
        int order;
 
-       order = ecap_pss(iommu->ecap) + 7 - PAGE_SHIFT;
-       if (order < 0)
-               order = 0;
-
+       /* Start at 2 because it's defined as 2^(1+PSS) */
+       iommu->pasid_max = 2 << ecap_pss(iommu->ecap);
+
+       /* Eventually I'm promised we will get a multi-level PASID table
+        * and it won't have to be physically contiguous. Until then,
+        * limit the size because 8MiB contiguous allocations can be hard
+        * to come by. The limit of 0x20000, which is 1MiB for each of
+        * the PASID and PASID-state tables, is somewhat arbitrary. */
+       if (iommu->pasid_max > 0x20000)
+               iommu->pasid_max = 0x20000;
+
+       order = get_order(sizeof(struct pasid_entry) * iommu->pasid_max);
        pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
        if (!pages) {
                pr_warn("IOMMU: %s: Failed to allocate PASID table\n",
@@ -53,6 +61,8 @@ int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu)
        pr_info("%s: Allocated order %d PASID table.\n", iommu->name, order);
 
        if (ecap_dis(iommu->ecap)) {
+               /* Just making it explicit... */
+               BUILD_BUG_ON(sizeof(struct pasid_entry) != sizeof(struct pasid_state_entry));
                pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
                if (pages)
                        iommu->pasid_state_table = page_address(pages);
@@ -68,11 +78,7 @@ int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu)
 
 int intel_svm_free_pasid_tables(struct intel_iommu *iommu)
 {
-       int order;
-
-       order = ecap_pss(iommu->ecap) + 7 - PAGE_SHIFT;
-       if (order < 0)
-               order = 0;
+       int order = get_order(sizeof(struct pasid_entry) * iommu->pasid_max);
 
        if (iommu->pasid_table) {
                free_pages((unsigned long)iommu->pasid_table, order);
@@ -371,8 +377,8 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_
                }
                svm->iommu = iommu;
 
-               if (pasid_max > 2 << ecap_pss(iommu->ecap))
-                       pasid_max = 2 << ecap_pss(iommu->ecap);
+               if (pasid_max > iommu->pasid_max)
+                       pasid_max = iommu->pasid_max;
 
                /* Do not use PASID 0 in caching mode (virtualised IOMMU) */
                ret = idr_alloc(&iommu->pasid_idr, svm,