1 files changed, 24 insertions, 8 deletions

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 2a46b1d7a601..a7cbcd46af9e 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -44,6 +44,24 @@
 
 #define LOOP_TIMEOUT    100000
 
+/*
+ * This bitmap is used to advertise the page sizes our hardware support
+ * to the IOMMU core, which will then use this information to split
+ * physically contiguous memory regions it is mapping into page sizes
+ * that we support.
+ *
+ * Traditionally the IOMMU core just handed us the mappings directly,
+ * after making sure the size is an order of a 4KiB page and that the
+ * mapping has natural alignment.
+ *
+ * To retain this behavior, we currently advertise that we support
+ * all page sizes that are an order of 4KiB.
+ *
+ * If at some point we'd like to utilize the IOMMU core's new behavior,
+ * we could change this to advertise the real page sizes we support.
+ */
+#define AMD_IOMMU_PGSIZES       (~0xFFFUL)
+
 static DEFINE_RWLOCK(amd_iommu_devtable_lock);
 
 /* A list of preallocated protection domains */
@@ -3093,9 +3111,8 @@ static int amd_iommu_attach_device(struct iommu_domain *dom,
 }
 
 static int amd_iommu_map(struct iommu_domain *dom, unsigned long iova,
-                         phys_addr_t paddr, int gfp_order, int iommu_prot)
+                         phys_addr_t paddr, size_t page_size, int iommu_prot)
 {
-        unsigned long page_size = 0x1000UL << gfp_order;
         struct protection_domain *domain = dom->priv;
         int prot = 0;
         int ret;
@@ -3115,24 +3132,22 @@ static int amd_iommu_map(struct iommu_domain *dom, unsigned long iova,
         return ret;
 }
 
-static int amd_iommu_unmap(struct iommu_domain *dom, unsigned long iova,
-                           int gfp_order)
+static size_t amd_iommu_unmap(struct iommu_domain *dom, unsigned long iova,
+                           size_t page_size)
 {
         struct protection_domain *domain = dom->priv;
-        unsigned long page_size, unmap_size;
+        size_t unmap_size;
 
         if (domain->mode == PAGE_MODE_NONE)
                 return -EINVAL;
 
-        page_size  = 0x1000UL << gfp_order;
-
         mutex_lock(&domain->api_lock);
         unmap_size = iommu_unmap_page(domain, iova, page_size);
         mutex_unlock(&domain->api_lock);
 
         domain_flush_tlb_pde(domain);
 
-        return get_order(unmap_size);
+        return unmap_size;
 }
 
 static phys_addr_t amd_iommu_iova_to_phys(struct iommu_domain *dom,
@@ -3182,6 +3197,7 @@ static struct iommu_ops amd_iommu_ops = {
         .unmap = amd_iommu_unmap,
         .iova_to_phys = amd_iommu_iova_to_phys,
         .domain_has_cap = amd_iommu_domain_has_cap,
+        .pgsize_bitmap  = AMD_IOMMU_PGSIZES,
 };
 
 /*****************************************************************************