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, 15 insertions, 27 deletions

diff --git a/linux-core/drm_vm.c b/linux-core/drm_vm.c
index b92552e6..93037bda 100644
--- a/linux-core/drm_vm.c
+++ b/linux-core/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 +70,12 @@ 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 == VM_OFFSET(vma))
-			break;
-	}
+        if (drm_ht_find_item(&dev->map_hash, (VM_OFFSET(vma) - DRM_MAP_HASH_OFFSET) >> 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;
@@ -556,9 +554,8 @@ 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, VM_OFFSET(vma));
@@ -578,22 +575,13 @@ 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 == VM_OFFSET(vma))
-			break;
-	}
+        if (drm_ht_find_item(&dev->map_hash, (VM_OFFSET(vma) - DRM_MAP_HASH_OFFSET) >> 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;