![Daniel Vetter](/assets/img/avatar_default.png)
This completes Emil's series of removing DRM_UNLOCKED from modern drivers. It's entirely cargo-culted since we ignore it on non-DRIVER_LEGACY drivers since: commitea487835e8
Author: Daniel Vetter <daniel.vetter@ffwll.ch> Date: Mon Sep 28 21:42:40 2015 +0200 drm: Enforce unlocked ioctl operation for kms driver ioctls Now justifying why we can do this for legacy drives too (and hence close the source of all the bogus copypasting) is a bit more involved. DRM_UNLOCKED was introduced in: commited8b670409
Author: Arnd Bergmann <arnd@arndb.de> Date: Wed Dec 16 22:17:09 2009 +0000 drm: convert drm_ioctl to unlocked_ioctl As a immediate hack to keep i810 happy, which would have deadlocked without this trickery. The old BKL is automatically dropped in schedule(), and hence the i810 vs. mmap_sem deadlock didn't actually cause a real deadlock. But with a mutex it would. The solution was to annotate these as DRM_UNLOCKED and mark i810 unsafe on SMP machines. This conversion caused a regression, because unlike the BKL a mutex isn't dropped over schedule (that thing again), which caused a vblank wait in one thread to block the entire desktop and all its apps. Back then we did vblank scheduling by blocking in the client, awesome isn't it. This was fixed quickly in (ok not so quickly, took 2 years): commit8f4ff2b06a
Author: Ilija Hadzic <ihadzic@research.bell-labs.com> Date: Mon Oct 31 17:46:18 2011 -0400 drm: do not sleep on vblank while holding a mutex All the other DRM_UNLOCKED annotations for all the core ioctls was work to reach finer-grained locking for modern drivers. This took years, and culminated in: commitfdd5b877e9
Author: Daniel Vetter <daniel.vetter@ffwll.ch> Date: Sat Dec 10 22:52:54 2016 +0100 drm: Enforce BKL-less ioctls for modern drivers DRM_UNLOCKED was never required by any legacy drivers, except for the vblank_wait IOCTL. Therefore we will not regress these old drivers by going back to where we've been in 2011. For all modern drivers nothing will change. To make this perfectly clear, also add a comment to DRM_UNLOCKED. v2: Don't forget about drm_ioc32.c (Michel). Cc: Michel Dänzer <michel@daenzer.net> Cc: Emil Velikov <emil.l.velikov@gmail.com> Acked-by: Emil Velikov <emil.velikov@collabora.com> Acked-by: Michel Dänzer <michel@daenzer.net> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190605120835.2798-1-daniel.vetter@ffwll.ch
186 lines
6.2 KiB
C
186 lines
6.2 KiB
C
/*
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* Internal Header for the Direct Rendering Manager
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*
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* Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
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* Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
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* Copyright (c) 2009-2010, Code Aurora Forum.
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* All rights reserved.
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*
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* Author: Rickard E. (Rik) Faith <faith@valinux.com>
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* Author: Gareth Hughes <gareth@valinux.com>
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice (including the next
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* paragraph) shall be included in all copies or substantial portions of the
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* Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
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* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
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* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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* OTHER DEALINGS IN THE SOFTWARE.
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*/
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#ifndef _DRM_IOCTL_H_
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#define _DRM_IOCTL_H_
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#include <linux/types.h>
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#include <linux/bitops.h>
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#include <asm/ioctl.h>
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struct drm_device;
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struct drm_file;
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struct file;
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/**
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* drm_ioctl_t - DRM ioctl function type.
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* @dev: DRM device inode
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* @data: private pointer of the ioctl call
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* @file_priv: DRM file this ioctl was made on
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*
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* This is the DRM ioctl typedef. Note that drm_ioctl() has alrady copied @data
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* into kernel-space, and will also copy it back, depending upon the read/write
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* settings in the ioctl command code.
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*/
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typedef int drm_ioctl_t(struct drm_device *dev, void *data,
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struct drm_file *file_priv);
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/**
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* drm_ioctl_compat_t - compatibility DRM ioctl function type.
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* @filp: file pointer
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* @cmd: ioctl command code
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* @arg: DRM file this ioctl was made on
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*
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* Just a typedef to make declaring an array of compatibility handlers easier.
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* New drivers shouldn't screw up the structure layout for their ioctl
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* structures and hence never need this.
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*/
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typedef int drm_ioctl_compat_t(struct file *filp, unsigned int cmd,
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unsigned long arg);
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#define DRM_IOCTL_NR(n) _IOC_NR(n)
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#define DRM_MAJOR 226
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/**
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* enum drm_ioctl_flags - DRM ioctl flags
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*
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* Various flags that can be set in &drm_ioctl_desc.flags to control how
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* userspace can use a given ioctl.
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*/
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enum drm_ioctl_flags {
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/**
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* @DRM_AUTH:
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*
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* This is for ioctl which are used for rendering, and require that the
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* file descriptor is either for a render node, or if it's a
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* legacy/primary node, then it must be authenticated.
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*/
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DRM_AUTH = BIT(0),
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/**
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* @DRM_MASTER:
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*
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* This must be set for any ioctl which can change the modeset or
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* display state. Userspace must call the ioctl through a primary node,
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* while it is the active master.
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*
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* Note that read-only modeset ioctl can also be called by
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* unauthenticated clients, or when a master is not the currently active
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* one.
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*/
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DRM_MASTER = BIT(1),
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/**
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* @DRM_ROOT_ONLY:
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*
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* Anything that could potentially wreak a master file descriptor needs
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* to have this flag set. Current that's only for the SETMASTER and
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* DROPMASTER ioctl, which e.g. logind can call to force a non-behaving
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* master (display compositor) into compliance.
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*
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* This is equivalent to callers with the SYSADMIN capability.
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*/
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DRM_ROOT_ONLY = BIT(2),
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/**
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* @DRM_UNLOCKED:
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*
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* Whether &drm_ioctl_desc.func should be called with the DRM BKL held
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* or not. Enforced as the default for all modern drivers, hence there
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* should never be a need to set this flag.
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*
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* Do not use anywhere else than for the VBLANK_WAIT IOCTL, which is the
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* only legacy IOCTL which needs this.
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*/
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DRM_UNLOCKED = BIT(4),
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/**
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* @DRM_RENDER_ALLOW:
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*
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* This is used for all ioctl needed for rendering only, for drivers
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* which support render nodes. This should be all new render drivers,
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* and hence it should be always set for any ioctl with DRM_AUTH set.
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* Note though that read-only query ioctl might have this set, but have
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* not set DRM_AUTH because they do not require authentication.
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*/
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DRM_RENDER_ALLOW = BIT(5),
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};
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/**
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* struct drm_ioctl_desc - DRM driver ioctl entry
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* @cmd: ioctl command number, without flags
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* @flags: a bitmask of &enum drm_ioctl_flags
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* @func: handler for this ioctl
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* @name: user-readable name for debug output
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*
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* For convenience it's easier to create these using the DRM_IOCTL_DEF_DRV()
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* macro.
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*/
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struct drm_ioctl_desc {
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unsigned int cmd;
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enum drm_ioctl_flags flags;
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drm_ioctl_t *func;
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const char *name;
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};
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/**
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* DRM_IOCTL_DEF_DRV() - helper macro to fill out a &struct drm_ioctl_desc
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* @ioctl: ioctl command suffix
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* @_func: handler for the ioctl
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* @_flags: a bitmask of &enum drm_ioctl_flags
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*
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* Small helper macro to create a &struct drm_ioctl_desc entry. The ioctl
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* command number is constructed by prepending ``DRM_IOCTL\_`` and passing that
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* to DRM_IOCTL_NR().
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*/
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#define DRM_IOCTL_DEF_DRV(ioctl, _func, _flags) \
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[DRM_IOCTL_NR(DRM_IOCTL_##ioctl) - DRM_COMMAND_BASE] = { \
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.cmd = DRM_IOCTL_##ioctl, \
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.func = _func, \
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.flags = _flags, \
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.name = #ioctl \
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}
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int drm_ioctl_permit(u32 flags, struct drm_file *file_priv);
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long drm_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
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long drm_ioctl_kernel(struct file *, drm_ioctl_t, void *, u32);
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#ifdef CONFIG_COMPAT
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long drm_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
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#else
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/* Let drm_compat_ioctl be assigned to .compat_ioctl unconditionally */
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#define drm_compat_ioctl NULL
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#endif
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bool drm_ioctl_flags(unsigned int nr, unsigned int *flags);
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int drm_noop(struct drm_device *dev, void *data,
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struct drm_file *file_priv);
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int drm_invalid_op(struct drm_device *dev, void *data,
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struct drm_file *file_priv);
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#endif /* _DRM_IOCTL_H_ */
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