1/*
2 * Copyright 2011 Red Hat, Inc.
3 * Copyright © 2014 The Chromium OS Authors
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software")
7 * to deal in the software without restriction, including without limitation
8 * on the rights to use, copy, modify, merge, publish, distribute, sub
9 * license, and/or sell copies of the Software, and to permit persons to whom
10 * them Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice (including the next
13 * paragraph) shall be included in all copies or substantial portions of the
14 * Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTIBILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES, OR OTHER LIABILITY, WHETHER
20 * IN AN ACTION OF CONTRACT, TORT, OR OTHERWISE, ARISING FROM, OUT OF OR IN
21 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22 *
23 * Authors:
24 * Adam Jackson <ajax@redhat.com>
25 * Ben Widawsky <ben@bwidawsk.net>
26 */
27
28/*
29 * This is vgem, a (non-hardware-backed) GEM service. This is used by Mesa's
30 * software renderer and the X server for efficient buffer sharing.
31 */
32
33#include <linux/dma-buf.h>
34#include <linux/module.h>
35#include <linux/platform_device.h>
36#include <linux/shmem_fs.h>
37#include <linux/vmalloc.h>
38
39#include <drm/drm_drv.h>
40#include <drm/drm_file.h>
41#include <drm/drm_gem_shmem_helper.h>
42#include <drm/drm_ioctl.h>
43#include <drm/drm_managed.h>
44#include <drm/drm_prime.h>
45
46#include "vgem_drv.h"
47
48#define DRIVER_NAME "vgem"
49#define DRIVER_DESC "Virtual GEM provider"
50#define DRIVER_DATE "20120112"
51#define DRIVER_MAJOR 1
52#define DRIVER_MINOR 0
53
54static struct vgem_device {
55 struct drm_device drm;
56 struct platform_device *platform;
57} *vgem_device;
58
59static int vgem_open(struct drm_device *dev, struct drm_file *file)
60{
61 struct vgem_file *vfile;
62 int ret;
63
64 vfile = kzalloc(size: sizeof(*vfile), GFP_KERNEL);
65 if (!vfile)
66 return -ENOMEM;
67
68 file->driver_priv = vfile;
69
70 ret = vgem_fence_open(file: vfile);
71 if (ret) {
72 kfree(objp: vfile);
73 return ret;
74 }
75
76 return 0;
77}
78
79static void vgem_postclose(struct drm_device *dev, struct drm_file *file)
80{
81 struct vgem_file *vfile = file->driver_priv;
82
83 vgem_fence_close(file: vfile);
84 kfree(objp: vfile);
85}
86
87static struct drm_ioctl_desc vgem_ioctls[] = {
88 DRM_IOCTL_DEF_DRV(VGEM_FENCE_ATTACH, vgem_fence_attach_ioctl, DRM_RENDER_ALLOW),
89 DRM_IOCTL_DEF_DRV(VGEM_FENCE_SIGNAL, vgem_fence_signal_ioctl, DRM_RENDER_ALLOW),
90};
91
92DEFINE_DRM_GEM_FOPS(vgem_driver_fops);
93
94static struct drm_gem_object *vgem_gem_create_object(struct drm_device *dev, size_t size)
95{
96 struct drm_gem_shmem_object *obj;
97
98 obj = kzalloc(size: sizeof(*obj), GFP_KERNEL);
99 if (!obj)
100 return ERR_PTR(error: -ENOMEM);
101
102 /*
103 * vgem doesn't have any begin/end cpu access ioctls, therefore must use
104 * coherent memory or dma-buf sharing just wont work.
105 */
106 obj->map_wc = true;
107
108 return &obj->base;
109}
110
111static const struct drm_driver vgem_driver = {
112 .driver_features = DRIVER_GEM | DRIVER_RENDER,
113 .open = vgem_open,
114 .postclose = vgem_postclose,
115 .ioctls = vgem_ioctls,
116 .num_ioctls = ARRAY_SIZE(vgem_ioctls),
117 .fops = &vgem_driver_fops,
118
119 DRM_GEM_SHMEM_DRIVER_OPS,
120 .gem_create_object = vgem_gem_create_object,
121
122 .name = DRIVER_NAME,
123 .desc = DRIVER_DESC,
124 .date = DRIVER_DATE,
125 .major = DRIVER_MAJOR,
126 .minor = DRIVER_MINOR,
127};
128
129static int __init vgem_init(void)
130{
131 int ret;
132 struct platform_device *pdev;
133
134 pdev = platform_device_register_simple(name: "vgem", id: -1, NULL, num: 0);
135 if (IS_ERR(ptr: pdev))
136 return PTR_ERR(ptr: pdev);
137
138 if (!devres_open_group(dev: &pdev->dev, NULL, GFP_KERNEL)) {
139 ret = -ENOMEM;
140 goto out_unregister;
141 }
142
143 dma_coerce_mask_and_coherent(dev: &pdev->dev,
144 DMA_BIT_MASK(64));
145
146 vgem_device = devm_drm_dev_alloc(&pdev->dev, &vgem_driver,
147 struct vgem_device, drm);
148 if (IS_ERR(ptr: vgem_device)) {
149 ret = PTR_ERR(ptr: vgem_device);
150 goto out_devres;
151 }
152 vgem_device->platform = pdev;
153
154 /* Final step: expose the device/driver to userspace */
155 ret = drm_dev_register(dev: &vgem_device->drm, flags: 0);
156 if (ret)
157 goto out_devres;
158
159 return 0;
160
161out_devres:
162 devres_release_group(dev: &pdev->dev, NULL);
163out_unregister:
164 platform_device_unregister(pdev);
165 return ret;
166}
167
168static void __exit vgem_exit(void)
169{
170 struct platform_device *pdev = vgem_device->platform;
171
172 drm_dev_unregister(dev: &vgem_device->drm);
173 devres_release_group(dev: &pdev->dev, NULL);
174 platform_device_unregister(pdev);
175}
176
177module_init(vgem_init);
178module_exit(vgem_exit);
179
180MODULE_AUTHOR("Red Hat, Inc.");
181MODULE_AUTHOR("Intel Corporation");
182MODULE_DESCRIPTION(DRIVER_DESC);
183MODULE_LICENSE("GPL and additional rights");
184

source code of linux/drivers/gpu/drm/vgem/vgem_drv.c