linux-imx

/*

 * Copyright © 2008 Intel Corporation

 *

 * 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

 * THE AUTHORS OR COPYRIGHT HOLDERS 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.

 *

 * Authors:

 *    Eric Anholt <eric@anholt.net>

 *

 */

​

#include <linux/types.h>

#include <linux/slab.h>

#include <linux/mm.h>

#include <linux/uaccess.h>

#include <linux/fs.h>

#include <linux/file.h>

#include <linux/module.h>

#include <linux/mman.h>

#include <linux/pagemap.h>

#include <linux/shmem_fs.h>

#include <linux/dma-buf.h>

#include <linux/mem_encrypt.h>

#include <linux/pagevec.h>

#include <drm/drmP.h>

#include <drm/drm_vma_manager.h>

#include <drm/drm_gem.h>

#include <drm/drm_print.h>

#include "drm_internal.h"

​

/** @file drm_gem.c

 *

 * This file provides some of the base ioctls and library routines for

 * the graphics memory manager implemented by each device driver.

 *

 * Because various devices have different requirements in terms of

 * synchronization and migration strategies, implementing that is left up to

 * the driver, and all that the general API provides should be generic --

 * allocating objects, reading/writing data with the cpu, freeing objects.

 * Even there, platform-dependent optimizations for reading/writing data with

 * the CPU mean we'll likely hook those out to driver-specific calls.  However,

 * the DRI2 implementation wants to have at least allocate/mmap be generic.

 *

 * The goal was to have swap-backed object allocation managed through

 * struct file.  However, file descriptors as handles to a struct file have

 * two major failings:

 * - Process limits prevent more than 1024 or so being used at a time by

 *   default.

 * - Inability to allocate high fds will aggravate the X Server's select()

 *   handling, and likely that of many GL client applications as well.

 *

 * This led to a plan of using our own integer IDs (called handles, following

 * DRM terminology) to mimic fds, and implement the fd syscalls we need as

 * ioctls.  The objects themselves will still include the struct file so

 * that we can transition to fds if the required kernel infrastructure shows

 * up at a later date, and as our interface with shmfs for memory allocation.

 */

​

/**

 * drm_gem_init - Initialize the GEM device fields

 * @dev: drm_devic structure to initialize

 */

int

drm_gem_init(struct drm_device *dev)

{

    struct drm_vma_offset_manager *vma_offset_manager;

​

    mutex_init(&dev->object_name_lock);

    idr_init_base(&dev->object_name_idr, 1);

​

    vma_offset_manager = kzalloc(sizeof(*vma_offset_manager), GFP_KERNEL);

    if (!vma_offset_manager) {

        DRM_ERROR("out of memory\n");

        return -ENOMEM;

    }

​