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 
54 static struct vgem_device {
55 	struct drm_device drm;
56 	struct platform_device *platform;
57 } *vgem_device;
58 
vgem_open(struct drm_device * dev,struct drm_file * file)59 static int vgem_open(struct drm_device *dev, struct drm_file *file)
60 {
61 	struct vgem_file *vfile;
62 	int ret;
63 
64 	vfile = kzalloc(sizeof(*vfile), GFP_KERNEL);
65 	if (!vfile)
66 		return -ENOMEM;
67 
68 	file->driver_priv = vfile;
69 
70 	ret = vgem_fence_open(vfile);
71 	if (ret) {
72 		kfree(vfile);
73 		return ret;
74 	}
75 
76 	return 0;
77 }
78 
vgem_postclose(struct drm_device * dev,struct drm_file * file)79 static 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(vfile);
84 	kfree(vfile);
85 }
86 
87 static 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 
92 DEFINE_DRM_GEM_FOPS(vgem_driver_fops);
93 
vgem_gem_create_object(struct drm_device * dev,size_t size)94 static 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(sizeof(*obj), GFP_KERNEL);
99 	if (!obj)
100 		return ERR_PTR(-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 
111 static 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 
vgem_init(void)129 static int __init vgem_init(void)
130 {
131 	int ret;
132 	struct platform_device *pdev;
133 
134 	pdev = platform_device_register_simple("vgem", -1, NULL, 0);
135 	if (IS_ERR(pdev))
136 		return PTR_ERR(pdev);
137 
138 	if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) {
139 		ret = -ENOMEM;
140 		goto out_unregister;
141 	}
142 
143 	dma_coerce_mask_and_coherent(&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(vgem_device)) {
149 		ret = PTR_ERR(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(&vgem_device->drm, 0);
156 	if (ret)
157 		goto out_devres;
158 
159 	return 0;
160 
161 out_devres:
162 	devres_release_group(&pdev->dev, NULL);
163 out_unregister:
164 	platform_device_unregister(pdev);
165 	return ret;
166 }
167 
vgem_exit(void)168 static void __exit vgem_exit(void)
169 {
170 	struct platform_device *pdev = vgem_device->platform;
171 
172 	drm_dev_unregister(&vgem_device->drm);
173 	devres_release_group(&pdev->dev, NULL);
174 	platform_device_unregister(pdev);
175 }
176 
177 module_init(vgem_init);
178 module_exit(vgem_exit);
179 
180 MODULE_AUTHOR("Red Hat, Inc.");
181 MODULE_AUTHOR("Intel Corporation");
182 MODULE_DESCRIPTION(DRIVER_DESC);
183 MODULE_LICENSE("GPL and additional rights");
184