xen-gntdev: Use find_vma rather than iterating our vma list manually
This should be faster if many mappings exist, and also removes
the only user of map->vma not related to PTE modification.
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 23d208a..ce8c37c 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -167,23 +167,6 @@
return NULL;
}
-static struct grant_map *gntdev_find_map_vaddr(struct gntdev_priv *priv,
- unsigned long vaddr)
-{
- struct grant_map *map;
-
- list_for_each_entry(map, &priv->maps, next) {
- if (!map->vma)
- continue;
- if (vaddr < map->vma->vm_start)
- continue;
- if (vaddr >= map->vma->vm_end)
- continue;
- return map;
- }
- return NULL;
-}
-
static int gntdev_del_map(struct grant_map *map)
{
int i;
@@ -494,22 +477,23 @@
struct ioctl_gntdev_get_offset_for_vaddr __user *u)
{
struct ioctl_gntdev_get_offset_for_vaddr op;
+ struct vm_area_struct *vma;
struct grant_map *map;
if (copy_from_user(&op, u, sizeof(op)) != 0)
return -EFAULT;
pr_debug("priv %p, offset for vaddr %lx\n", priv, (unsigned long)op.vaddr);
- spin_lock(&priv->lock);
- map = gntdev_find_map_vaddr(priv, op.vaddr);
- if (map == NULL ||
- map->vma->vm_start != op.vaddr) {
- spin_unlock(&priv->lock);
+ vma = find_vma(current->mm, op.vaddr);
+ if (!vma || vma->vm_ops != &gntdev_vmops)
return -EINVAL;
- }
+
+ map = vma->vm_private_data;
+ if (!map)
+ return -EINVAL;
+
op.offset = map->index << PAGE_SHIFT;
op.count = map->count;
- spin_unlock(&priv->lock);
if (copy_to_user(u, &op, sizeof(op)) != 0)
return -EFAULT;