iommu/amd: Optimize iommu_unmap_page for new fetch_pte interface
authorJoerg Roedel <jroedel@suse.de>
Wed, 1 Apr 2015 12:58:49 +0000 (14:58 +0200)
committerJoerg Roedel <jroedel@suse.de>
Thu, 2 Apr 2015 11:31:07 +0000 (13:31 +0200)
Now that fetch_pte returns the page-size of the pte, this
function can be optimized a lot.

Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
drivers/iommu/amd_iommu.c

index 24ef9e600289fd97935cf7079f55308bddce2a91..c9ee444d82090df7ed65b65adee9b8e1e662e8f0 100644 (file)
@@ -1428,8 +1428,8 @@ static unsigned long iommu_unmap_page(struct protection_domain *dom,
                                      unsigned long bus_addr,
                                      unsigned long page_size)
 {
-       unsigned long long unmap_size, unmapped;
-       unsigned long pte_pgsize;
+       unsigned long long unmapped;
+       unsigned long unmap_size;
        u64 *pte;
 
        BUG_ON(!is_power_of_2(page_size));
@@ -1438,28 +1438,12 @@ static unsigned long iommu_unmap_page(struct protection_domain *dom,
 
        while (unmapped < page_size) {
 
-               pte = fetch_pte(dom, bus_addr, &pte_pgsize);
-
-               if (!pte) {
-                       /*
-                        * No PTE for this address
-                        * move forward in 4kb steps
-                        */
-                       unmap_size = PAGE_SIZE;
-               } else if (PM_PTE_LEVEL(*pte) == 0) {
-                       /* 4kb PTE found for this address */
-                       unmap_size = PAGE_SIZE;
-                       *pte       = 0ULL;
-               } else {
-                       int count, i;
-
-                       /* Large PTE found which maps this address */
-                       unmap_size = PTE_PAGE_SIZE(*pte);
-
-                       /* Only unmap from the first pte in the page */
-                       if ((unmap_size - 1) & bus_addr)
-                               break;
-                       count      = PAGE_SIZE_PTE_COUNT(unmap_size);
+               pte = fetch_pte(dom, bus_addr, &unmap_size);
+
+               if (pte) {
+                       int i, count;
+
+                       count = PAGE_SIZE_PTE_COUNT(unmap_size);
                        for (i = 0; i < count; i++)
                                pte[i] = 0ULL;
                }