drm/vmwgfx: Remove vmwgfx_hashtab

The vmwgfx driver has migrated from using the hashtable in vmwgfx_hashtab
to the linux/hashtable implementation. Remove the vmwgfx_hashtab from the
driver.
Signed-off-by: Maaz Mombasawala <mombasawalam@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Reviewed-by: Zack Rusin <zackr@vmware.com>
Signed-off-by: Zack Rusin <zackr@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221022040236.616490-12-zack@kde.org

Documentation/gpu/todo.rst

@@ -651,17 +651,6 @@ See drivers/gpu/drm/amd/display/TODO for tasks.
 
 Contact: Harry Wentland, Alex Deucher
 
-vmwgfx: Replace hashtable with Linux' implementation
-----------------------------------------------------
-
-The vmwgfx driver uses its own hashtable implementation. Replace the
-code with Linux' implementation and update the callers. It's mostly a
-refactoring task, but the interfaces are different.
-
-Contact: Zack Rusin, Thomas Zimmermann <tzimmermann@suse.de>
-
-Level: Intermediate
-
 Bootsplash
 ==========
 

drivers/gpu/drm/vmwgfx/Makefile

 # SPDX-License-Identifier: GPL-2.0
-vmwgfx-y := vmwgfx_execbuf.o vmwgfx_gmr.o vmwgfx_hashtab.o vmwgfx_kms.o vmwgfx_drv.o \
+vmwgfx-y := vmwgfx_execbuf.o vmwgfx_gmr.o vmwgfx_kms.o vmwgfx_drv.o \
 	    vmwgfx_ioctl.o vmwgfx_resource.o vmwgfx_ttm_buffer.o \
 	    vmwgfx_cmd.o vmwgfx_irq.o vmwgfx_ldu.o vmwgfx_ttm_glue.o \
 	    vmwgfx_overlay.o vmwgfx_gmrid_manager.o vmwgfx_fence.o \

drivers/gpu/drm/vmwgfx/ttm_object.c

@@ -284,7 +284,7 @@ ttm_base_object_noref_lookup(struct ttm_object_file *tfile, uint64_t key)
 	}
 
 	__release(RCU);
-	return drm_hash_entry(hash, struct ttm_ref_object, hash)->obj;
+	return hlist_entry(hash, struct ttm_ref_object, hash)->obj;
 }
 EXPORT_SYMBOL(ttm_base_object_noref_lookup);
 
@@ -299,7 +299,7 @@ struct ttm_base_object *ttm_base_object_lookup(struct ttm_object_file *tfile,
 	ret = ttm_tfile_find_ref_rcu(tfile, key, &hash);
 
 	if (likely(ret == 0)) {
-		base = drm_hash_entry(hash, struct ttm_ref_object, hash)->obj;
+		base = hlist_entry(hash, struct ttm_ref_object, hash)->obj;
 		if (!kref_get_unless_zero(&base->refcount))
 			base = NULL;
 	}
@@ -343,7 +343,7 @@ int ttm_ref_object_add(struct ttm_object_file *tfile,
 		ret = ttm_tfile_find_ref_rcu(tfile, base->handle, &hash);
 
 		if (ret == 0) {
-			ref = drm_hash_entry(hash, struct ttm_ref_object, hash);
+			ref = hlist_entry(hash, struct ttm_ref_object, hash);
 			if (kref_get_unless_zero(&ref->kref)) {
 				rcu_read_unlock();
 				break;
@@ -407,7 +407,7 @@ int ttm_ref_object_base_unref(struct ttm_object_file *tfile,
 		spin_unlock(&tfile->lock);
 		return -EINVAL;
 	}
-	ref = drm_hash_entry(hash, struct ttm_ref_object, hash);
+	ref = hlist_entry(hash, struct ttm_ref_object, hash);
 	kref_put(&ref->kref, ttm_ref_object_release);
 	spin_unlock(&tfile->lock);
 	return 0;

drivers/gpu/drm/vmwgfx/ttm_object.h

@@ -42,8 +42,6 @@
 #include <linux/list.h>
 #include <linux/rcupdate.h>
 
-#include "vmwgfx_hashtab.h"
-
 /**
  * enum ttm_object_type
  *

drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf_res.c

@@ -88,7 +88,7 @@ vmw_cmdbuf_res_lookup(struct vmw_cmdbuf_res_manager *man,
 
 	hash_for_each_possible_rcu(man->resources, hash, head, key) {
 		if (hash->key == key)
-			return drm_hash_entry(hash, struct vmw_cmdbuf_res, hash)->res;
+			return hlist_entry(hash, struct vmw_cmdbuf_res, hash)->res;
 	}
 	return ERR_PTR(-EINVAL);
 }
@@ -243,7 +243,7 @@ int vmw_cmdbuf_res_remove(struct vmw_cmdbuf_res_manager *man,
 
 	hash_for_each_possible_rcu(man->resources, hash, head, key) {
 		if (hash->key == key) {
-			entry = drm_hash_entry(hash, struct vmw_cmdbuf_res, hash);
+			entry = hlist_entry(hash, struct vmw_cmdbuf_res, hash);
 			break;
 		}
 	}

drivers/gpu/drm/vmwgfx/vmwgfx_drv.h

@@ -43,7 +43,6 @@
 #include "ttm_object.h"
 
 #include "vmwgfx_fence.h"
-#include "vmwgfx_hashtab.h"
 #include "vmwgfx_reg.h"
 #include "vmwgfx_validation.h"
 
@@ -104,6 +103,11 @@ struct vmw_fpriv {
 	bool gb_aware; /* user-space is guest-backed aware */
 };
 
+struct vmwgfx_hash_item {
+	struct hlist_node head;
+	unsigned long key;
+};
+
 /**
  * struct vmw_buffer_object - TTM buffer object with vmwgfx additions
  * @base: The TTM buffer object

drivers/gpu/drm/vmwgfx/vmwgfx_hashtab.c

-/*
- * 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 <linux/export.h>
-#include <linux/hash.h>
-#include <linux/mm.h>
-#include <linux/rculist.h>
-#include <linux/slab.h>
-#include <linux/vmalloc.h>
-
-#include <drm/drm_print.h>
-
-#include "vmwgfx_hashtab.h"
-
-int vmwgfx_ht_create(struct vmwgfx_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;
-}
-
-void vmwgfx_ht_verbose_list(struct vmwgfx_open_hash *ht, unsigned long key)
-{
-	struct vmwgfx_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 *vmwgfx_ht_find_key(struct vmwgfx_open_hash *ht, unsigned long key)
-{
-	struct vmwgfx_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 *vmwgfx_ht_find_key_rcu(struct vmwgfx_open_hash *ht, unsigned long key)
-{
-	struct vmwgfx_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 vmwgfx_ht_insert_item(struct vmwgfx_open_hash *ht, struct vmwgfx_hash_item *item)
-{
-	struct vmwgfx_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;
-}
-
-/*
- * Just insert an item and return any "bits" bit key that hasn't been
- * used before.
- */
-int vmwgfx_ht_just_insert_please(struct vmwgfx_open_hash *ht, struct vmwgfx_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 = vmwgfx_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;
-}
-
-int vmwgfx_ht_find_item(struct vmwgfx_open_hash *ht, unsigned long key,
-			struct vmwgfx_hash_item **item)
-{
-	struct hlist_node *list;
-
-	list = vmwgfx_ht_find_key_rcu(ht, key);
-	if (!list)
-		return -EINVAL;
-
-	*item = hlist_entry(list, struct vmwgfx_hash_item, head);
-	return 0;
-}
-
-int vmwgfx_ht_remove_key(struct vmwgfx_open_hash *ht, unsigned long key)
-{
-	struct hlist_node *list;
-
-	list = vmwgfx_ht_find_key(ht, key);
-	if (list) {
-		hlist_del_init_rcu(list);
-		return 0;
-	}
-	return -EINVAL;
-}
-
-int vmwgfx_ht_remove_item(struct vmwgfx_open_hash *ht, struct vmwgfx_hash_item *item)
-{
-	hlist_del_init_rcu(&item->head);
-	return 0;
-}
-
-void vmwgfx_ht_remove(struct vmwgfx_open_hash *ht)
-{
-	if (ht->table) {
-		kvfree(ht->table);
-		ht->table = NULL;
-	}
-}

drivers/gpu/drm/vmwgfx/vmwgfx_hashtab.h

-/*
- * Copyright 2006 Tungsten Graphics, Inc., Bismack, 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>
- */
-
-/*
- * TODO: Replace this hashtable with Linux' generic implementation
- *       from <linux/hashtable.h>.
- */
-
-#ifndef VMWGFX_HASHTAB_H
-#define VMWGFX_HASHTAB_H
-
-#include <linux/list.h>
-
-#define drm_hash_entry(_ptr, _type, _member) container_of(_ptr, _type, _member)
-
-struct vmwgfx_hash_item {
-	struct hlist_node head;
-	unsigned long key;
-};
-
-struct vmwgfx_open_hash {
-	struct hlist_head *table;
-	u8 order;
-};
-
-int vmwgfx_ht_create(struct vmwgfx_open_hash *ht, unsigned int order);
-int vmwgfx_ht_insert_item(struct vmwgfx_open_hash *ht, struct vmwgfx_hash_item *item);
-int vmwgfx_ht_just_insert_please(struct vmwgfx_open_hash *ht, struct vmwgfx_hash_item *item,
-				 unsigned long seed, int bits, int shift,
-				 unsigned long add);
-int vmwgfx_ht_find_item(struct vmwgfx_open_hash *ht, unsigned long key,
-			struct vmwgfx_hash_item **item);
-
-void vmwgfx_ht_verbose_list(struct vmwgfx_open_hash *ht, unsigned long key);
-int vmwgfx_ht_remove_key(struct vmwgfx_open_hash *ht, unsigned long key);
-int vmwgfx_ht_remove_item(struct vmwgfx_open_hash *ht, struct vmwgfx_hash_item *item);
-void vmwgfx_ht_remove(struct vmwgfx_open_hash *ht);
-
-/*
- * RCU-safe interface
- *
- * The user of this API needs to make sure that two or more instances of the
- * hash table manipulation functions are never run simultaneously.
- * The lookup function vmwgfx_ht_find_item_rcu may, however, run simultaneously
- * with any of the manipulation functions as long as it's called from within
- * an RCU read-locked section.
- */
-#define vmwgfx_ht_insert_item_rcu vmwgfx_ht_insert_item
-#define vmwgfx_ht_just_insert_please_rcu vmwgfx_ht_just_insert_please
-#define vmwgfx_ht_remove_key_rcu vmwgfx_ht_remove_key
-#define vmwgfx_ht_remove_item_rcu vmwgfx_ht_remove_item
-#define vmwgfx_ht_find_item_rcu vmwgfx_ht_find_item
-
-#endif