v4.19.13 snapshot.
diff --git a/drivers/gpu/drm/drm_hashtab.c b/drivers/gpu/drm/drm_hashtab.c
new file mode 100644
index 0000000..c92b00d
--- /dev/null
+++ b/drivers/gpu/drm/drm_hashtab.c
@@ -0,0 +1,205 @@
+/**************************************************************************
+ *
+ * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND. USA.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ *
+ **************************************************************************/
+/*
+ * Simple open hash tab implementation.
+ *
+ * Authors:
+ * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
+ */
+
+#include <drm/drmP.h>
+#include <drm/drm_hashtab.h>
+#include <linux/hash.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+
+int drm_ht_create(struct drm_open_hash *ht, unsigned int order)
+{
+ unsigned int size = 1 << order;
+
+ ht->order = order;
+ ht->table = NULL;
+ if (size <= PAGE_SIZE / sizeof(*ht->table))
+ ht->table = kcalloc(size, sizeof(*ht->table), GFP_KERNEL);
+ else
+ ht->table = vzalloc(array_size(size, sizeof(*ht->table)));
+ if (!ht->table) {
+ DRM_ERROR("Out of memory for hash table\n");
+ return -ENOMEM;
+ }
+ return 0;
+}
+EXPORT_SYMBOL(drm_ht_create);
+
+void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key)
+{
+ struct drm_hash_item *entry;
+ struct hlist_head *h_list;
+ unsigned int hashed_key;
+ int count = 0;
+
+ hashed_key = hash_long(key, ht->order);
+ DRM_DEBUG("Key is 0x%08lx, Hashed key is 0x%08x\n", key, hashed_key);
+ h_list = &ht->table[hashed_key];
+ hlist_for_each_entry(entry, h_list, head)
+ DRM_DEBUG("count %d, key: 0x%08lx\n", count++, entry->key);
+}
+
+static struct hlist_node *drm_ht_find_key(struct drm_open_hash *ht,
+ unsigned long key)
+{
+ struct drm_hash_item *entry;
+ struct hlist_head *h_list;
+ unsigned int hashed_key;
+
+ hashed_key = hash_long(key, ht->order);
+ h_list = &ht->table[hashed_key];
+ hlist_for_each_entry(entry, h_list, head) {
+ if (entry->key == key)
+ return &entry->head;
+ if (entry->key > key)
+ break;
+ }
+ return NULL;
+}
+
+static struct hlist_node *drm_ht_find_key_rcu(struct drm_open_hash *ht,
+ unsigned long key)
+{
+ struct drm_hash_item *entry;
+ struct hlist_head *h_list;
+ unsigned int hashed_key;
+
+ hashed_key = hash_long(key, ht->order);
+ h_list = &ht->table[hashed_key];
+ hlist_for_each_entry_rcu(entry, h_list, head) {
+ if (entry->key == key)
+ return &entry->head;
+ if (entry->key > key)
+ break;
+ }
+ return NULL;
+}
+
+int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item)
+{
+ struct drm_hash_item *entry;
+ struct hlist_head *h_list;
+ struct hlist_node *parent;
+ unsigned int hashed_key;
+ unsigned long key = item->key;
+
+ hashed_key = hash_long(key, ht->order);
+ h_list = &ht->table[hashed_key];
+ parent = NULL;
+ hlist_for_each_entry(entry, h_list, head) {
+ if (entry->key == key)
+ return -EINVAL;
+ if (entry->key > key)
+ break;
+ parent = &entry->head;
+ }
+ if (parent) {
+ hlist_add_behind_rcu(&item->head, parent);
+ } else {
+ hlist_add_head_rcu(&item->head, h_list);
+ }
+ return 0;
+}
+EXPORT_SYMBOL(drm_ht_insert_item);
+
+/*
+ * Just insert an item and return any "bits" bit key that hasn't been
+ * used before.
+ */
+int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *item,
+ unsigned long seed, int bits, int shift,
+ unsigned long add)
+{
+ int ret;
+ unsigned long mask = (1UL << bits) - 1;
+ unsigned long first, unshifted_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)
+ unshifted_key = (unshifted_key + 1) & mask;
+ } while(ret && (unshifted_key != first));
+
+ if (ret) {
+ DRM_ERROR("Available key bit space exhausted\n");
+ return -EINVAL;
+ }
+ return 0;
+}
+EXPORT_SYMBOL(drm_ht_just_insert_please);
+
+int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key,
+ struct drm_hash_item **item)
+{
+ struct hlist_node *list;
+
+ list = drm_ht_find_key_rcu(ht, key);
+ if (!list)
+ return -EINVAL;
+
+ *item = hlist_entry(list, struct drm_hash_item, head);
+ return 0;
+}
+EXPORT_SYMBOL(drm_ht_find_item);
+
+int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key)
+{
+ struct hlist_node *list;
+
+ list = drm_ht_find_key(ht, key);
+ if (list) {
+ hlist_del_init_rcu(list);
+ return 0;
+ }
+ return -EINVAL;
+}
+
+int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item)
+{
+ hlist_del_init_rcu(&item->head);
+ return 0;
+}
+EXPORT_SYMBOL(drm_ht_remove_item);
+
+void drm_ht_remove(struct drm_open_hash *ht)
+{
+ if (ht->table) {
+ kvfree(ht->table);
+ ht->table = NULL;
+ }
+}
+EXPORT_SYMBOL(drm_ht_remove);