Branch data 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 : :
33 : : /**
34 : : * DOC: overview
35 : : *
36 : : * The KMS API doesn't standardize backing storage object creation and leaves it
37 : : * to driver-specific ioctls. Furthermore actually creating a buffer object even
38 : : * for GEM-based drivers is done through a driver-specific ioctl - GEM only has
39 : : * a common userspace interface for sharing and destroying objects. While not an
40 : : * issue for full-fledged graphics stacks that include device-specific userspace
41 : : * components (in libdrm for instance), this limit makes DRM-based early boot
42 : : * graphics unnecessarily complex.
43 : : *
44 : : * Dumb objects partly alleviate the problem by providing a standard API to
45 : : * create dumb buffers suitable for scanout, which can then be used to create
46 : : * KMS frame buffers.
47 : : *
48 : : * To support dumb objects drivers must implement the &drm_driver.dumb_create
49 : : * operation. &drm_driver.dumb_destroy defaults to drm_gem_dumb_destroy() if
50 : : * not set and &drm_driver.dumb_map_offset defaults to
51 : : * drm_gem_dumb_map_offset(). See the callbacks for further details.
52 : : *
53 : : * Note that dumb objects may not be used for gpu acceleration, as has been
54 : : * attempted on some ARM embedded platforms. Such drivers really must have
55 : : * a hardware-specific ioctl to allocate suitable buffer objects.
56 : : */
57 : :
58 : 0 : int drm_mode_create_dumb(struct drm_device *dev,
59 : : struct drm_mode_create_dumb *args,
60 : : struct drm_file *file_priv)
61 : : {
62 : 0 : u32 cpp, stride, size;
63 : :
64 [ # # ]: 0 : if (!dev->driver->dumb_create)
65 : : return -ENOSYS;
66 [ # # # # : 0 : if (!args->width || !args->height || !args->bpp)
# # ]
67 : : return -EINVAL;
68 : :
69 : : /* overflow checks for 32bit size calculations */
70 [ # # ]: 0 : if (args->bpp > U32_MAX - 8)
71 : : return -EINVAL;
72 : 0 : cpp = DIV_ROUND_UP(args->bpp, 8);
73 [ # # ]: 0 : if (cpp > U32_MAX / args->width)
74 : : return -EINVAL;
75 : 0 : stride = cpp * args->width;
76 [ # # ]: 0 : if (args->height > U32_MAX / stride)
77 : : return -EINVAL;
78 : :
79 : : /* test for wrap-around */
80 : 0 : size = args->height * stride;
81 [ # # ]: 0 : if (PAGE_ALIGN(size) == 0)
82 : : return -EINVAL;
83 : :
84 : : /*
85 : : * handle, pitch and size are output parameters. Zero them out to
86 : : * prevent drivers from accidentally using uninitialized data. Since
87 : : * not all existing userspace is clearing these fields properly we
88 : : * cannot reject IOCTL with garbage in them.
89 : : */
90 : 0 : args->handle = 0;
91 : 0 : args->pitch = 0;
92 : 0 : args->size = 0;
93 : :
94 : 0 : return dev->driver->dumb_create(file_priv, dev, args);
95 : : }
96 : :
97 : 0 : int drm_mode_create_dumb_ioctl(struct drm_device *dev,
98 : : void *data, struct drm_file *file_priv)
99 : : {
100 : 0 : return drm_mode_create_dumb(dev, data, file_priv);
101 : : }
102 : :
103 : : /**
104 : : * drm_mode_mmap_dumb_ioctl - create an mmap offset for a dumb backing storage buffer
105 : : * @dev: DRM device
106 : : * @data: ioctl data
107 : : * @file_priv: DRM file info
108 : : *
109 : : * Allocate an offset in the drm device node's address space to be able to
110 : : * memory map a dumb buffer.
111 : : *
112 : : * Called by the user via ioctl.
113 : : *
114 : : * Returns:
115 : : * Zero on success, negative errno on failure.
116 : : */
117 : 0 : int drm_mode_mmap_dumb_ioctl(struct drm_device *dev,
118 : : void *data, struct drm_file *file_priv)
119 : : {
120 : 0 : struct drm_mode_map_dumb *args = data;
121 : :
122 [ # # ]: 0 : if (!dev->driver->dumb_create)
123 : : return -ENOSYS;
124 : :
125 [ # # ]: 0 : if (dev->driver->dumb_map_offset)
126 : 0 : return dev->driver->dumb_map_offset(file_priv, dev,
127 : : args->handle,
128 : 0 : &args->offset);
129 : : else
130 : 0 : return drm_gem_dumb_map_offset(file_priv, dev, args->handle,
131 : 0 : &args->offset);
132 : : }
133 : :
134 : 0 : int drm_mode_destroy_dumb(struct drm_device *dev, u32 handle,
135 : : struct drm_file *file_priv)
136 : : {
137 [ # # ]: 0 : if (!dev->driver->dumb_create)
138 : : return -ENOSYS;
139 : :
140 [ # # ]: 0 : if (dev->driver->dumb_destroy)
141 : 0 : return dev->driver->dumb_destroy(file_priv, dev, handle);
142 : : else
143 : 0 : return drm_gem_dumb_destroy(file_priv, dev, handle);
144 : : }
145 : :
146 : 0 : int drm_mode_destroy_dumb_ioctl(struct drm_device *dev,
147 : : void *data, struct drm_file *file_priv)
148 : : {
149 : 0 : struct drm_mode_destroy_dumb *args = data;
150 : :
151 : 0 : return drm_mode_destroy_dumb(dev, args->handle, file_priv);
152 : : }
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