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 | 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 | if (!dev->driver->dumb_create) |
67 | return -ENOSYS; |
68 | if (!args->width || !args->height || !args->bpp) |
69 | return -EINVAL; |
70 | |
71 | /* overflow checks for 32bit size calculations */ |
72 | if (args->bpp > U32_MAX - 8) |
73 | return -EINVAL; |
74 | cpp = DIV_ROUND_UP(args->bpp, 8); |
75 | if (cpp > U32_MAX / args->width) |
76 | return -EINVAL; |
77 | stride = cpp * args->width; |
78 | if (args->height > U32_MAX / stride) |
79 | return -EINVAL; |
80 | |
81 | /* test for wrap-around */ |
82 | size = args->height * stride; |
83 | 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 | args->handle = 0; |
93 | args->pitch = 0; |
94 | args->size = 0; |
95 | |
96 | return dev->driver->dumb_create(file_priv, dev, args); |
97 | } |
98 | |
99 | int drm_mode_create_dumb_ioctl(struct drm_device *dev, |
100 | void *data, struct drm_file *file_priv) |
101 | { |
102 | return drm_mode_create_dumb(dev, args: 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 | int drm_mode_mmap_dumb_ioctl(struct drm_device *dev, |
120 | void *data, struct drm_file *file_priv) |
121 | { |
122 | struct drm_mode_map_dumb *args = data; |
123 | |
124 | if (!dev->driver->dumb_create) |
125 | return -ENOSYS; |
126 | |
127 | if (dev->driver->dumb_map_offset) |
128 | return dev->driver->dumb_map_offset(file_priv, dev, |
129 | args->handle, |
130 | &args->offset); |
131 | else |
132 | return drm_gem_dumb_map_offset(file: file_priv, dev, handle: args->handle, |
133 | offset: &args->offset); |
134 | } |
135 | |
136 | int drm_mode_destroy_dumb(struct drm_device *dev, u32 handle, |
137 | struct drm_file *file_priv) |
138 | { |
139 | if (!dev->driver->dumb_create) |
140 | return -ENOSYS; |
141 | |
142 | return drm_gem_handle_delete(filp: file_priv, handle); |
143 | } |
144 | |
145 | int drm_mode_destroy_dumb_ioctl(struct drm_device *dev, |
146 | void *data, struct drm_file *file_priv) |
147 | { |
148 | struct drm_mode_destroy_dumb *args = data; |
149 | |
150 | return drm_mode_destroy_dumb(dev, handle: args->handle, file_priv); |
151 | } |
152 | |