Line data Source code
1 : /*
2 : * Copyright (c) 2006-2008 Intel Corporation
3 : * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
4 : * Copyright (c) 2008 Red Hat Inc.
5 : * Copyright (c) 2016 Intel Corporation
6 : *
7 : * Permission to use, copy, modify, distribute, and sell this software and its
8 : * documentation for any purpose is hereby granted without fee, provided that
9 : * the above copyright notice appear in all copies and that both that copyright
10 : * notice and this permission notice appear in supporting documentation, and
11 : * that the name of the copyright holders not be used in advertising or
12 : * publicity pertaining to distribution of the software without specific,
13 : * written prior permission. The copyright holders make no representations
14 : * about the suitability of this software for any purpose. It is provided "as
15 : * is" without express or implied warranty.
16 : *
17 : * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
18 : * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
19 : * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
20 : * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
21 : * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
22 : * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
23 : * OF THIS SOFTWARE.
24 : */
25 :
26 : #include <drm/drm_device.h>
27 : #include <drm/drm_drv.h>
28 : #include <drm/drm_gem.h>
29 : #include <drm/drm_mode.h>
30 :
31 : #include "drm_crtc_internal.h"
32 : #include "drm_internal.h"
33 :
34 : /**
35 : * DOC: overview
36 : *
37 : * The KMS API doesn't standardize backing storage object creation and leaves it
38 : * to driver-specific ioctls. Furthermore actually creating a buffer object even
39 : * for GEM-based drivers is done through a driver-specific ioctl - GEM only has
40 : * a common userspace interface for sharing and destroying objects. While not an
41 : * issue for full-fledged graphics stacks that include device-specific userspace
42 : * components (in libdrm for instance), this limit makes DRM-based early boot
43 : * graphics unnecessarily complex.
44 : *
45 : * Dumb objects partly alleviate the problem by providing a standard API to
46 : * create dumb buffers suitable for scanout, which can then be used to create
47 : * KMS frame buffers.
48 : *
49 : * To support dumb objects drivers must implement the &drm_driver.dumb_create
50 : * and &drm_driver.dumb_map_offset operations (the latter defaults to
51 : * drm_gem_dumb_map_offset() if not set). Drivers that don't use GEM handles
52 : * additionally need to implement the &drm_driver.dumb_destroy operation. See
53 : * the callbacks for further details.
54 : *
55 : * Note that dumb objects may not be used for gpu acceleration, as has been
56 : * attempted on some ARM embedded platforms. Such drivers really must have
57 : * a hardware-specific ioctl to allocate suitable buffer objects.
58 : */
59 :
60 0 : int drm_mode_create_dumb(struct drm_device *dev,
61 : struct drm_mode_create_dumb *args,
62 : struct drm_file *file_priv)
63 : {
64 : u32 cpp, stride, size;
65 :
66 0 : if (!dev->driver->dumb_create)
67 : return -ENOSYS;
68 0 : if (!args->width || !args->height || !args->bpp)
69 : return -EINVAL;
70 :
71 : /* overflow checks for 32bit size calculations */
72 0 : if (args->bpp > U32_MAX - 8)
73 : return -EINVAL;
74 0 : cpp = DIV_ROUND_UP(args->bpp, 8);
75 0 : if (cpp > U32_MAX / args->width)
76 : return -EINVAL;
77 0 : stride = cpp * args->width;
78 0 : if (args->height > U32_MAX / stride)
79 : return -EINVAL;
80 :
81 : /* test for wrap-around */
82 0 : size = args->height * stride;
83 0 : if (PAGE_ALIGN(size) == 0)
84 : return -EINVAL;
85 :
86 : /*
87 : * handle, pitch and size are output parameters. Zero them out to
88 : * prevent drivers from accidentally using uninitialized data. Since
89 : * not all existing userspace is clearing these fields properly we
90 : * cannot reject IOCTL with garbage in them.
91 : */
92 0 : args->handle = 0;
93 0 : args->pitch = 0;
94 0 : args->size = 0;
95 :
96 0 : return dev->driver->dumb_create(file_priv, dev, args);
97 : }
98 :
99 0 : int drm_mode_create_dumb_ioctl(struct drm_device *dev,
100 : void *data, struct drm_file *file_priv)
101 : {
102 0 : return drm_mode_create_dumb(dev, data, file_priv);
103 : }
104 :
105 : /**
106 : * drm_mode_mmap_dumb_ioctl - create an mmap offset for a dumb backing storage buffer
107 : * @dev: DRM device
108 : * @data: ioctl data
109 : * @file_priv: DRM file info
110 : *
111 : * Allocate an offset in the drm device node's address space to be able to
112 : * memory map a dumb buffer.
113 : *
114 : * Called by the user via ioctl.
115 : *
116 : * Returns:
117 : * Zero on success, negative errno on failure.
118 : */
119 0 : int drm_mode_mmap_dumb_ioctl(struct drm_device *dev,
120 : void *data, struct drm_file *file_priv)
121 : {
122 0 : struct drm_mode_map_dumb *args = data;
123 :
124 0 : if (!dev->driver->dumb_create)
125 : return -ENOSYS;
126 :
127 0 : if (dev->driver->dumb_map_offset)
128 0 : return dev->driver->dumb_map_offset(file_priv, dev,
129 : args->handle,
130 0 : &args->offset);
131 : else
132 0 : return drm_gem_dumb_map_offset(file_priv, dev, args->handle,
133 0 : &args->offset);
134 : }
135 :
136 0 : int drm_mode_destroy_dumb(struct drm_device *dev, u32 handle,
137 : struct drm_file *file_priv)
138 : {
139 0 : if (!dev->driver->dumb_create)
140 : return -ENOSYS;
141 :
142 0 : if (dev->driver->dumb_destroy)
143 0 : return dev->driver->dumb_destroy(file_priv, dev, handle);
144 : else
145 0 : return drm_gem_dumb_destroy(file_priv, dev, handle);
146 : }
147 :
148 0 : int drm_mode_destroy_dumb_ioctl(struct drm_device *dev,
149 : void *data, struct drm_file *file_priv)
150 : {
151 0 : struct drm_mode_destroy_dumb *args = data;
152 :
153 0 : return drm_mode_destroy_dumb(dev, args->handle, file_priv);
154 : }
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