xref: /openbmc/linux/include/drm/drm_ioctl.h (revision f9834f18)
1 /*
2  * Internal Header for the Direct Rendering Manager
3  *
4  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
5  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
6  * Copyright (c) 2009-2010, Code Aurora Forum.
7  * All rights reserved.
8  *
9  * Author: Rickard E. (Rik) Faith <faith@valinux.com>
10  * Author: Gareth Hughes <gareth@valinux.com>
11  *
12  * Permission is hereby granted, free of charge, to any person obtaining a
13  * copy of this software and associated documentation files (the "Software"),
14  * to deal in the Software without restriction, including without limitation
15  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
16  * and/or sell copies of the Software, and to permit persons to whom the
17  * Software is furnished to do so, subject to the following conditions:
18  *
19  * The above copyright notice and this permission notice (including the next
20  * paragraph) shall be included in all copies or substantial portions of the
21  * Software.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
24  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
25  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
26  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
27  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
28  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
29  * OTHER DEALINGS IN THE SOFTWARE.
30  */
31 
32 #ifndef _DRM_IOCTL_H_
33 #define _DRM_IOCTL_H_
34 
35 #include <linux/types.h>
36 #include <linux/bitops.h>
37 
38 #include <asm/ioctl.h>
39 
40 struct drm_device;
41 struct drm_file;
42 struct file;
43 
44 /**
45  * drm_ioctl_t - DRM ioctl function type.
46  * @dev: DRM device inode
47  * @data: private pointer of the ioctl call
48  * @file_priv: DRM file this ioctl was made on
49  *
50  * This is the DRM ioctl typedef. Note that drm_ioctl() has alrady copied @data
51  * into kernel-space, and will also copy it back, depending upon the read/write
52  * settings in the ioctl command code.
53  */
54 typedef int drm_ioctl_t(struct drm_device *dev, void *data,
55 			struct drm_file *file_priv);
56 
57 /**
58  * drm_ioctl_compat_t - compatibility DRM ioctl function type.
59  * @filp: file pointer
60  * @cmd: ioctl command code
61  * @arg: DRM file this ioctl was made on
62  *
63  * Just a typedef to make declaring an array of compatibility handlers easier.
64  * New drivers shouldn't screw up the structure layout for their ioctl
65  * structures and hence never need this.
66  */
67 typedef int drm_ioctl_compat_t(struct file *filp, unsigned int cmd,
68 			       unsigned long arg);
69 
70 #define DRM_IOCTL_NR(n)                _IOC_NR(n)
71 #define DRM_MAJOR       226
72 
73 /**
74  * enum drm_ioctl_flags - DRM ioctl flags
75  *
76  * Various flags that can be set in &drm_ioctl_desc.flags to control how
77  * userspace can use a given ioctl.
78  */
79 enum drm_ioctl_flags {
80 	/**
81 	 * @DRM_AUTH:
82 	 *
83 	 * This is for ioctl which are used for rendering, and require that the
84 	 * file descriptor is either for a render node, or if it's a
85 	 * legacy/primary node, then it must be authenticated.
86 	 */
87 	DRM_AUTH		= BIT(0),
88 	/**
89 	 * @DRM_MASTER:
90 	 *
91 	 * This must be set for any ioctl which can change the modeset or
92 	 * display state. Userspace must call the ioctl through a primary node,
93 	 * while it is the active master.
94 	 *
95 	 * Note that read-only modeset ioctl can also be called by
96 	 * unauthenticated clients, or when a master is not the currently active
97 	 * one.
98 	 */
99 	DRM_MASTER		= BIT(1),
100 	/**
101 	 * @DRM_ROOT_ONLY:
102 	 *
103 	 * Anything that could potentially wreak a master file descriptor needs
104 	 * to have this flag set. Current that's only for the SETMASTER and
105 	 * DROPMASTER ioctl, which e.g. logind can call to force a non-behaving
106 	 * master (display compositor) into compliance.
107 	 *
108 	 * This is equivalent to callers with the SYSADMIN capability.
109 	 */
110 	DRM_ROOT_ONLY		= BIT(2),
111 	/**
112 	 * @DRM_UNLOCKED:
113 	 *
114 	 * Whether &drm_ioctl_desc.func should be called with the DRM BKL held
115 	 * or not. Enforced as the default for all modern drivers, hence there
116 	 * should never be a need to set this flag.
117 	 *
118 	 * Do not use anywhere else than for the VBLANK_WAIT IOCTL, which is the
119 	 * only legacy IOCTL which needs this.
120 	 */
121 	DRM_UNLOCKED		= BIT(4),
122 	/**
123 	 * @DRM_RENDER_ALLOW:
124 	 *
125 	 * This is used for all ioctl needed for rendering only, for drivers
126 	 * which support render nodes. This should be all new render drivers,
127 	 * and hence it should be always set for any ioctl with DRM_AUTH set.
128 	 * Note though that read-only query ioctl might have this set, but have
129 	 * not set DRM_AUTH because they do not require authentication.
130 	 */
131 	DRM_RENDER_ALLOW	= BIT(5),
132 };
133 
134 /**
135  * struct drm_ioctl_desc - DRM driver ioctl entry
136  * @cmd: ioctl command number, without flags
137  * @flags: a bitmask of &enum drm_ioctl_flags
138  * @func: handler for this ioctl
139  * @name: user-readable name for debug output
140  *
141  * For convenience it's easier to create these using the DRM_IOCTL_DEF_DRV()
142  * macro.
143  */
144 struct drm_ioctl_desc {
145 	unsigned int cmd;
146 	enum drm_ioctl_flags flags;
147 	drm_ioctl_t *func;
148 	const char *name;
149 };
150 
151 /**
152  * DRM_IOCTL_DEF_DRV() - helper macro to fill out a &struct drm_ioctl_desc
153  * @ioctl: ioctl command suffix
154  * @_func: handler for the ioctl
155  * @_flags: a bitmask of &enum drm_ioctl_flags
156  *
157  * Small helper macro to create a &struct drm_ioctl_desc entry. The ioctl
158  * command number is constructed by prepending ``DRM_IOCTL\_`` and passing that
159  * to DRM_IOCTL_NR().
160  */
161 #define DRM_IOCTL_DEF_DRV(ioctl, _func, _flags)				\
162 	[DRM_IOCTL_NR(DRM_IOCTL_##ioctl) - DRM_COMMAND_BASE] = {	\
163 		.cmd = DRM_IOCTL_##ioctl,				\
164 		.func = _func,						\
165 		.flags = _flags,					\
166 		.name = #ioctl						\
167 	}
168 
169 int drm_ioctl_permit(u32 flags, struct drm_file *file_priv);
170 long drm_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
171 long drm_ioctl_kernel(struct file *, drm_ioctl_t, void *, u32);
172 #ifdef CONFIG_COMPAT
173 long drm_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
174 #else
175 /* Let drm_compat_ioctl be assigned to .compat_ioctl unconditionally */
176 #define drm_compat_ioctl NULL
177 #endif
178 bool drm_ioctl_flags(unsigned int nr, unsigned int *flags);
179 
180 int drm_noop(struct drm_device *dev, void *data,
181 	     struct drm_file *file_priv);
182 int drm_invalid_op(struct drm_device *dev, void *data,
183 		   struct drm_file *file_priv);
184 
185 #endif /* _DRM_IOCTL_H_ */
186