linux-imx

/*

 * Legacy: Generic DRM Buffer Management

 *

 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.

 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.

 * All Rights Reserved.

 *

 * Author: Rickard E. (Rik) Faith <faith@valinux.com>

 * Author: Gareth Hughes <gareth@valinux.com>

 *

 * 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, sublicense,

 * 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 NONINFRINGEMENT.  IN NO EVENT SHALL

 * VA LINUX SYSTEMS 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.

 */

​

#include <linux/vmalloc.h>

#include <linux/slab.h>

#include <linux/log2.h>

#include <linux/export.h>

#include <asm/shmparam.h>

#include <drm/drmP.h>

#include "drm_legacy.h"

​

#include <linux/nospec.h>

​

static struct drm_map_list *drm_find_matching_map(struct drm_device *dev,

                          struct drm_local_map *map)

{

    struct drm_map_list *entry;

    list_for_each_entry(entry, &dev->maplist, head) {

        /*

         * Because the kernel-userspace ABI is fixed at a 32-bit offset

         * while PCI resources may live above that, we only compare the

         * lower 32 bits of the map offset for maps of type

         * _DRM_FRAMEBUFFER or _DRM_REGISTERS.

         * It is assumed that if a driver have more than one resource

         * of each type, the lower 32 bits are different.

         */

        if (!entry->map ||

            map->type != entry->map->type ||

            entry->master != dev->master)

            continue;

        switch (map->type) {

        case _DRM_SHM:

            if (map->flags != _DRM_CONTAINS_LOCK)

                break;

            return entry;

        case _DRM_REGISTERS: