1 files changed, 5 insertions, 33 deletions

diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index d96d311b858e..017ce600fbc6 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -36,6 +36,7 @@
 
 #include <xen/xen.h>
 #include <xen/grant_table.h>
+#include <xen/balloon.h>
 #include <xen/gntdev.h>
 #include <xen/events.h>
 #include <asm/xen/hypervisor.h>
@@ -122,10 +123,10 @@ static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
             NULL == add->pages)
                 goto err;
 
+        if (alloc_xenballooned_pages(count, add->pages))
+                goto err;
+
         for (i = 0; i < count; i++) {
-                add->pages[i] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
-                if (add->pages[i] == NULL)
-                        goto err;
                 add->map_ops[i].handle = -1;
                 add->unmap_ops[i].handle = -1;
         }
@@ -137,11 +138,6 @@ static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
         return add;
 
 err:
-        if (add->pages)
-                for (i = 0; i < count; i++) {
-                        if (add->pages[i])
-                                __free_page(add->pages[i]);
-                }
         kfree(add->pages);
         kfree(add->grants);
         kfree(add->map_ops);
@@ -184,8 +180,6 @@ static struct grant_map *gntdev_find_map_index(struct gntdev_priv *priv,
 
 static void gntdev_put_map(struct grant_map *map)
 {
-        int i;
-
         if (!map)
                 return;
 
@@ -202,29 +196,7 @@ static void gntdev_put_map(struct grant_map *map)
                 if (!use_ptemod)
                         unmap_grant_pages(map, 0, map->count);
 
-                for (i = 0; i < map->count; i++) {
-                        uint32_t check, *tmp;
-                        if (!map->pages[i])
-                                continue;
-                        /* XXX When unmapping in an HVM domain, Xen will
-                         * sometimes end up mapping the GFN to an invalid MFN.
-                         * In this case, writes will be discarded and reads will
-                         * return all 0xFF bytes.  Leak these unusable GFNs
-                         * until Xen supports fixing their p2m mapping.
-                         *
-                         * Confirmed present in Xen 4.1-RC3 with HVM source
-                         */
-                        tmp = kmap(map->pages[i]);
-                        *tmp = 0xdeaddead;
-                        mb();
-                        check = *tmp;
-                        kunmap(map->pages[i]);
-                        if (check == 0xdeaddead)
-                                __free_page(map->pages[i]);
-                        else
-                                pr_debug("Discard page %d=%ld\n", i,
-                                        page_to_pfn(map->pages[i]));
-                }
+                free_xenballooned_pages(map->count, map->pages);
         }
         kfree(map->pages);
         kfree(map->grants);