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.
This keeps compatibility with buggy drivers, while still implementing a
    hashed map lookup. The SiS and via device driver major bumps are
    reverted.

1 files changed, 8 insertions, 6 deletions

diff --git a/linux-core/drm_hashtab.c b/linux-core/drm_hashtab.c
index 3be781df..d8c4549e 100644
--- a/linux-core/drm_hashtab.c
+++ b/linux-core/drm_hashtab.c
@@ -128,19 +128,21 @@ drm_ht_insert_item(drm_open_hash_t *ht, drm_hash_item_t *item)
 
 int
 drm_ht_just_insert_please(drm_open_hash_t *ht, drm_hash_item_t *item,
-                          unsigned long seed, int bits)
+                          unsigned long seed, int bits, int shift, 
+			  unsigned long add)
 {
         int ret;
         unsigned long mask = (1 << bits) - 1;
-        unsigned long first;
+        unsigned long first, unshifted_key;
 
-        item->key = hash_long(seed, bits);
-        first = item->key;
+        unshifted_key = hash_long(seed, bits);
+        first = unshifted_key;
         do{
+	        item->key = (unshifted_key << shift) + add;
                 ret = drm_ht_insert_item(ht, item);
                 if (ret)
-                        item->key = (item->key + 1) & mask; 
-        } while(ret && (item->key != first));
+                        unshifted_key = (unshifted_key + 1) & mask; 
+        } while(ret && (unshifted_key != first));
 
         if (ret) {
                 DRM_ERROR("Available key bit space exhausted\n");