xen gntdev: use gnttab_map_refs and gnttab_unmap_refs

Use gnttab_map_refs and gnttab_unmap_refs to map and unmap the grant
ref, so that we can have a corresponding struct page.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 30 insertions, 7 deletions

diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index aba76d437ea8..1e31cdcdae1e 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -71,6 +71,7 @@ struct grant_map {
         struct ioctl_gntdev_grant_ref *grants;
         struct gnttab_map_grant_ref   *map_ops;
         struct gnttab_unmap_grant_ref *unmap_ops;
+        struct page **pages;
 };
 
 /* ------------------------------------------------------------------ */
@@ -94,6 +95,7 @@ static void gntdev_print_maps(struct gntdev_priv *priv,
 static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
 {
         struct grant_map *add;
+        int i;
 
         add = kzalloc(sizeof(struct grant_map), GFP_KERNEL);
         if (NULL == add)
@@ -102,11 +104,19 @@ static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
         add->grants    = kzalloc(sizeof(add->grants[0])    * count, GFP_KERNEL);
         add->map_ops   = kzalloc(sizeof(add->map_ops[0])   * count, GFP_KERNEL);
         add->unmap_ops = kzalloc(sizeof(add->unmap_ops[0]) * count, GFP_KERNEL);
-        if (NULL == add->grants  ||
-            NULL == add->map_ops ||
-            NULL == add->unmap_ops)
+        add->pages     = kzalloc(sizeof(add->pages[0])     * count, GFP_KERNEL);
+        if (NULL == add->grants    ||
+            NULL == add->map_ops   ||
+            NULL == add->unmap_ops ||
+            NULL == 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->index = 0;
         add->count = count;
         add->priv  = priv;
@@ -117,6 +127,12 @@ 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);
         kfree(add->unmap_ops);
@@ -191,8 +207,17 @@ static int gntdev_del_map(struct grant_map *map)
 
 static void gntdev_free_map(struct grant_map *map)
 {
+        int i;
+
         if (!map)
                 return;
+
+        if (map->pages)
+                for (i = 0; i < map->count; i++) {
+                        if (map->pages[i])
+                                __free_page(map->pages[i]);
+                }
+        kfree(map->pages);
         kfree(map->grants);
         kfree(map->map_ops);
         kfree(map->unmap_ops);
@@ -226,8 +251,7 @@ static int map_grant_pages(struct grant_map *map)
         int i, err = 0;
 
         pr_debug("map %d+%d\n", map->index, map->count);
-        err = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref,
-                                        map->map_ops, map->count);
+        err = gnttab_map_refs(map->map_ops, map->pages, map->count);
         if (err)
                 return err;
 
@@ -244,8 +268,7 @@ static int unmap_grant_pages(struct grant_map *map, int offset, int pages)
         int i, err = 0;
 
         pr_debug("map %d+%d [%d+%d]\n", map->index, map->count, offset, pages);
-        err = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
-                                        map->unmap_ops + offset, pages);
+        err = gnttab_unmap_refs(map->unmap_ops + offset, map->pages, pages);
         if (err)
                 return err;