drm: update user token hashing and map handles

Keep hashed user tokens, with the following changes:
32-bit physical device addresses are mapped directly to user-tokens. No
    duplicate maps are allowed, and the addresses are assumed to be outside
    of the range 0x10000000 through 0x30000000. The user-token is identical
    to the 32-bit physical start-address of the map.
64-bit physical device addressed are mapped to user-tokens in the range
0x10000000 to 0x30000000 with page-size increments. The user_token should
    not be interpreted as an address.
Other map types, like upcoming TTM maps are mapped to user-tokens in the
    range
0x10000000 to 0x30000000 with page-size increments. The user_token should
    not be interpreted as an address.

Implement hashed map lookups.

Signed-off-by: Dave Airlie <airlied@linux.ie>

1 files changed, 11 insertions, 26 deletions

diff --git a/drivers/char/drm/drm_vm.c b/drivers/char/drm/drm_vm.c
index afb4f0a44b81..b40ae438f531 100644
--- a/drivers/char/drm/drm_vm.c
+++ b/drivers/char/drm/drm_vm.c
@@ -59,7 +59,7 @@ static __inline__ struct page *drm_do_vm_nopage(struct vm_area_struct *vma,
         drm_device_t *dev = priv->head->dev;
         drm_map_t *map = NULL;
         drm_map_list_t *r_list;
-        struct list_head *list;
+        drm_hash_item_t *hash;
 
         /*
          * Find the right map
@@ -70,14 +70,11 @@ static __inline__ struct page *drm_do_vm_nopage(struct vm_area_struct *vma,
         if (!dev->agp || !dev->agp->cant_use_aperture)
                 goto vm_nopage_error;
 
-        list_for_each(list, &dev->maplist->head) {
-                r_list = list_entry(list, drm_map_list_t, head);
-                map = r_list->map;
-                if (!map)
-                        continue;
-                if (r_list->user_token == (vma->vm_pgoff << PAGE_SHIFT))
-                        break;
-        }
+        if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff << PAGE_SHIFT, &hash))
+                goto vm_nopage_error;
+
+        r_list = drm_hash_entry(hash, drm_map_list_t, hash);
+        map = r_list->map;
 
         if (map && map->type == _DRM_AGP) {
                 unsigned long offset = address - vma->vm_start;
@@ -521,9 +518,8 @@ int drm_mmap(struct file *filp, struct vm_area_struct *vma)
         drm_file_t *priv = filp->private_data;
         drm_device_t *dev = priv->head->dev;
         drm_map_t *map = NULL;
-        drm_map_list_t *r_list;
         unsigned long offset = 0;
-        struct list_head *list;
+        drm_hash_item_t *hash;
 
         DRM_DEBUG("start = 0x%lx, end = 0x%lx, offset = 0x%lx\n",
                   vma->vm_start, vma->vm_end, vma->vm_pgoff << PAGE_SHIFT);
@@ -543,23 +539,12 @@ int drm_mmap(struct file *filp, struct vm_area_struct *vma)
             )
                 return drm_mmap_dma(filp, vma);
 
-        /* A sequential search of a linked list is
-           fine here because: 1) there will only be
-           about 5-10 entries in the list and, 2) a
-           DRI client only has to do this mapping
-           once, so it doesn't have to be optimized
-           for performance, even if the list was a
-           bit longer. */
-        list_for_each(list, &dev->maplist->head) {
-
-                r_list = list_entry(list, drm_map_list_t, head);
-                map = r_list->map;
-                if (!map)
-                        continue;
-                if (r_list->user_token == vma->vm_pgoff << PAGE_SHIFT)
-                        break;
+        if (drm_ht_find_item(&dev->map_hash, vma->vm_pgoff << PAGE_SHIFT, &hash)) {
+                DRM_ERROR("Could not find map\n");
+                return -EINVAL;
         }
 
+        map = drm_hash_entry(hash, drm_map_list_t, hash)->map;
         if (!map || ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN)))
                 return -EPERM;