Change drm Map handles to be arbitrary 32-bit hash tokens in the range

    0x10000000 to 0x90000000 in PAGE_SIZE increments.
Implement hashed map lookups.
This potentially breaks both 2D and 3D drivers. If so, the corresponding
2D and 3D driver should be fixed, and it's corresponding drm device driver
    should have its major bumped as soon as possible.
Bump sis and via drm device driver majors.
The SiS and Unichrome 3D drivers are fixed in Mesa CVS HEAD and
    mesa_6_4_branch.

1 files changed, 14 insertions, 41 deletions

diff --git a/linux-core/drm_bufs.c b/linux-core/drm_bufs.c
index eb478ba2..44705259 100644
--- a/linux-core/drm_bufs.c
+++ b/linux-core/drm_bufs.c
@@ -65,44 +65,6 @@ static drm_map_list_t *drm_find_matching_map(drm_device_t *dev,
 	return NULL;
 }
 
-/*
- * Used to allocate 32-bit handles for mappings.
- */
-#define START_RANGE 0x10000000
-#define END_RANGE 0x40000000
-
-#ifdef _LP64
-static __inline__ unsigned int HandleID(unsigned long lhandle,
-					drm_device_t *dev) 
-{
-	static unsigned int map32_handle = START_RANGE;
-	unsigned int hash;
-
-	if (lhandle & 0xffffffff00000000) {
-		hash = map32_handle;
-		map32_handle += PAGE_SIZE;
-		if (map32_handle > END_RANGE)
-			map32_handle = START_RANGE;
-	} else
-		hash = lhandle;
-
-	while (1) {
-		drm_map_list_t *_entry;
-		list_for_each_entry(_entry, &dev->maplist->head, head) {
-			if (_entry->user_token == hash)
-				break;
-		}
-		if (&_entry->head == &dev->maplist->head)
-			return hash;
-
-		hash += PAGE_SIZE;
-		map32_handle += PAGE_SIZE;
-	}
-}
-#else
-# define HandleID(x,dev) (unsigned int)(x)
-#endif
-
 /**
  * Ioctl to specify a range of memory that is available for mapping by a non-root process.
  *
@@ -300,9 +262,18 @@ static int drm_addmap_core(drm_device_t * dev, unsigned int offset,
 	list_add(&list->head, &dev->maplist->head);
 	/* Assign a 32-bit handle */
 	/* We do it here so that dev->struct_sem protects the increment */
-	list->user_token = HandleID(map->type == _DRM_SHM
-				    ? (unsigned long)map->handle
-				    : map->offset, dev);
+
+        if (drm_ht_just_insert_please(&dev->map_hash, &list->hash, 
+				      ((map->type == _DRM_SHM) ? (unsigned long)map->handle : 
+                                       map->offset) >> PAGE_SHIFT,
+				      32 - PAGE_SHIFT - 1)) {
+                drm_free(map, sizeof(*map), DRM_MEM_MAPS);
+                drm_free(list, sizeof(*list), DRM_MEM_MAPS);
+                up(&dev->struct_sem);
+                return -ENOMEM;
+	}
+
+	list->user_token = (list->hash.key << PAGE_SHIFT) + DRM_MAP_HASH_OFFSET;
 	up(&dev->struct_sem);
 
 	*maplist = list;
@@ -387,6 +358,8 @@ int drm_rmmap_locked(drm_device_t *dev, drm_local_map_t *map)
 
 		if (r_list->map == map) {
 			list_del(list);
+                        drm_ht_remove_key(&dev->map_hash, 
+                                          (r_list->user_token - DRM_MAP_HASH_OFFSET) >> PAGE_SHIFT);
 			drm_free(list, sizeof(*list), DRM_MEM_MAPS);
 			break;
 		}