Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2)  * Copyright (C) 2014 Red Hat
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * Author: Rob Clark <robdclark@gmail.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * Permission is hereby granted, free of charge, to any person obtaining a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  * copy of this software and associated documentation files (the "Software"),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  * to deal in the Software without restriction, including without limitation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  * and/or sell copies of the Software, and to permit persons to whom the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)  * Software is furnished to do so, subject to the following conditions:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12)  * The above copyright notice and this permission notice shall be included in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13)  * all copies or substantial portions of the Software.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15)  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16)  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17)  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18)  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19)  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20)  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21)  * OTHER DEALINGS IN THE SOFTWARE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) #ifndef DRM_MODESET_LOCK_H_
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) #define DRM_MODESET_LOCK_H_
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) #include <linux/ww_mutex.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) struct drm_modeset_lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32)  * struct drm_modeset_acquire_ctx - locking context (see ww_acquire_ctx)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33)  * @ww_ctx: base acquire ctx
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34)  * @contended: used internally for -EDEADLK handling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35)  * @locked: list of held locks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36)  * @trylock_only: trylock mode used in atomic contexts/panic notifiers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37)  * @interruptible: whether interruptible locking should be used.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39)  * Each thread competing for a set of locks must use one acquire
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40)  * ctx.  And if any lock fxn returns -EDEADLK, it must backoff and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41)  * retry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) struct drm_modeset_acquire_ctx {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 	struct ww_acquire_ctx ww_ctx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 	 * Contended lock: if a lock is contended you should only call
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 	 * drm_modeset_backoff() which drops locks and slow-locks the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 	 * contended lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 	struct drm_modeset_lock *contended;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	 * list of held locks (drm_modeset_lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	struct list_head locked;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	 * Trylock mode, use only for panic handlers!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	bool trylock_only;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	/* Perform interruptible waits on this context. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	bool interruptible;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69)  * struct drm_modeset_lock - used for locking modeset resources.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70)  * @mutex: resource locking
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71)  * @head: used to hold its place on &drm_atomi_state.locked list when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72)  *    part of an atomic update
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74)  * Used for locking CRTCs and other modeset resources.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) struct drm_modeset_lock {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	 * modeset lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	struct ww_mutex mutex;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 	 * Resources that are locked as part of an atomic update are added
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 	 * to a list (so we know what to unlock at the end).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 	struct list_head head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) #define DRM_MODESET_ACQUIRE_INTERRUPTIBLE BIT(0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) void drm_modeset_acquire_init(struct drm_modeset_acquire_ctx *ctx,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 		uint32_t flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) void drm_modeset_acquire_fini(struct drm_modeset_acquire_ctx *ctx);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) void drm_modeset_drop_locks(struct drm_modeset_acquire_ctx *ctx);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) int drm_modeset_backoff(struct drm_modeset_acquire_ctx *ctx);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) void drm_modeset_lock_init(struct drm_modeset_lock *lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)  * drm_modeset_lock_fini - cleanup lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)  * @lock: lock to cleanup
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) static inline void drm_modeset_lock_fini(struct drm_modeset_lock *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	WARN_ON(!list_empty(&lock->head));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)  * drm_modeset_is_locked - equivalent to mutex_is_locked()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)  * @lock: lock to check
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) static inline bool drm_modeset_is_locked(struct drm_modeset_lock *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	return ww_mutex_is_locked(&lock->mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)  * drm_modeset_lock_assert_held - equivalent to lockdep_assert_held()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)  * @lock: lock to check
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) static inline void drm_modeset_lock_assert_held(struct drm_modeset_lock *lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	lockdep_assert_held(&lock->mutex.base);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) int drm_modeset_lock(struct drm_modeset_lock *lock,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 		struct drm_modeset_acquire_ctx *ctx);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) int __must_check drm_modeset_lock_single_interruptible(struct drm_modeset_lock *lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) void drm_modeset_unlock(struct drm_modeset_lock *lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) struct drm_device;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) struct drm_crtc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) struct drm_plane;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) void drm_modeset_lock_all(struct drm_device *dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) void drm_modeset_unlock_all(struct drm_device *dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) void drm_warn_on_modeset_not_all_locked(struct drm_device *dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) int drm_modeset_lock_all_ctx(struct drm_device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 			     struct drm_modeset_acquire_ctx *ctx);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143)  * DRM_MODESET_LOCK_ALL_BEGIN - Helper to acquire modeset locks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)  * @dev: drm device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145)  * @ctx: local modeset acquire context, will be dereferenced
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)  * @flags: DRM_MODESET_ACQUIRE_* flags to pass to drm_modeset_acquire_init()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147)  * @ret: local ret/err/etc variable to track error status
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149)  * Use these macros to simplify grabbing all modeset locks using a local
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)  * context. This has the advantage of reducing boilerplate, but also properly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151)  * checking return values where appropriate.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153)  * Any code run between BEGIN and END will be holding the modeset locks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155)  * This must be paired with DRM_MODESET_LOCK_ALL_END(). We will jump back and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156)  * forth between the labels on deadlock and error conditions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158)  * Drivers can acquire additional modeset locks. If any lock acquisition
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159)  * fails, the control flow needs to jump to DRM_MODESET_LOCK_ALL_END() with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160)  * the @ret parameter containing the return value of drm_modeset_lock().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162)  * Returns:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163)  * The only possible value of ret immediately after DRM_MODESET_LOCK_ALL_BEGIN()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164)  * is 0, so no error checking is necessary
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) #define DRM_MODESET_LOCK_ALL_BEGIN(dev, ctx, flags, ret)		\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	if (!drm_drv_uses_atomic_modeset(dev))				\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 		mutex_lock(&dev->mode_config.mutex);			\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 	drm_modeset_acquire_init(&ctx, flags);				\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) modeset_lock_retry:							\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	ret = drm_modeset_lock_all_ctx(dev, &ctx);			\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 	if (ret)							\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 		goto modeset_lock_fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176)  * DRM_MODESET_LOCK_ALL_END - Helper to release and cleanup modeset locks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177)  * @dev: drm device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178)  * @ctx: local modeset acquire context, will be dereferenced
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179)  * @ret: local ret/err/etc variable to track error status
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181)  * The other side of DRM_MODESET_LOCK_ALL_BEGIN(). It will bounce back to BEGIN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182)  * if ret is -EDEADLK.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184)  * It's important that you use the same ret variable for begin and end so
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185)  * deadlock conditions are properly handled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187)  * Returns:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188)  * ret will be untouched unless it is -EDEADLK on entry. That means that if you
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189)  * successfully acquire the locks, ret will be whatever your code sets it to. If
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190)  * there is a deadlock or other failure with acquire or backoff, ret will be set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191)  * to that failure. In both of these cases the code between BEGIN/END will not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192)  * be run, so the failure will reflect the inability to grab the locks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) #define DRM_MODESET_LOCK_ALL_END(dev, ctx, ret)				\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) modeset_lock_fail:							\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 	if (ret == -EDEADLK) {						\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 		ret = drm_modeset_backoff(&ctx);			\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 		if (!ret)						\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 			goto modeset_lock_retry;			\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 	}								\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 	drm_modeset_drop_locks(&ctx);					\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 	drm_modeset_acquire_fini(&ctx);					\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 	if (!drm_drv_uses_atomic_modeset(dev))				\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 		mutex_unlock(&dev->mode_config.mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) #endif /* DRM_MODESET_LOCK_H_ */