gpu/drm/drm_modeset_lock.c

37  * of extra utility/tracking out of our acquire-ctx.  This is provided
44  *     drm_modeset_acquire_init(ctx, DRM_MODESET_ACQUIRE_INTERRUPTIBLE)
47  *         ret = drm_modeset_lock(lock, ctx)
49  *             ret = drm_modeset_backoff(ctx);
58  *     drm_modeset_drop_locks(ctx);
59  *     drm_modeset_acquire_fini(ctx);
67  * by passing a NULL instead of ctx in the drm_modeset_lock() call or
146 	struct drm_modeset_acquire_ctx *ctx;
149 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL | __GFP_NOFAIL);
150 	if (WARN_ON(!ctx))
155 	drm_modeset_acquire_init(ctx, 0);
158 	ret = drm_modeset_lock_all_ctx(dev, ctx);
161 			drm_modeset_backoff(ctx);
165 		drm_modeset_acquire_fini(ctx);
166 		kfree(ctx);
169 	ww_acquire_done(&ctx->ww_ctx);
177 	config->acquire_ctx = ctx;
200 	struct drm_modeset_acquire_ctx *ctx = config->acquire_ctx;
202 	if (WARN_ON(!ctx))
206 	drm_modeset_drop_locks(ctx);
207 	drm_modeset_acquire_fini(ctx);
209 	kfree(ctx);
239  * @ctx: the acquire context
246 void drm_modeset_acquire_init(struct drm_modeset_acquire_ctx *ctx,
249 	memset(ctx, 0, sizeof(*ctx));
250 	ww_acquire_init(&ctx->ww_ctx, &crtc_ww_class);
251 	INIT_LIST_HEAD(&ctx->locked);
254 		ctx->interruptible = true;
260  * @ctx: the acquire context
262 void drm_modeset_acquire_fini(struct drm_modeset_acquire_ctx *ctx)
264 	ww_acquire_fini(&ctx->ww_ctx);
270  * @ctx: the acquire context
274 void drm_modeset_drop_locks(struct drm_modeset_acquire_ctx *ctx)
276 	if (WARN_ON(ctx->contended))
277 		__drm_stack_depot_print(ctx->stack_depot);
279 	while (!list_empty(&ctx->locked)) {
282 		lock = list_first_entry(&ctx->locked,
291 		struct drm_modeset_acquire_ctx *ctx,
296 	if (WARN_ON(ctx->contended))
297 		__drm_stack_depot_print(ctx->stack_depot);
299 	if (ctx->trylock_only) {
300 		lockdep_assert_held(&ctx->ww_ctx);
307 		ret = ww_mutex_lock_slow_interruptible(&lock->mutex, &ctx->ww_ctx);
309 		ret = ww_mutex_lock_interruptible(&lock->mutex, &ctx->ww_ctx);
311 		ww_mutex_lock_slow(&lock->mutex, &ctx->ww_ctx);
314 		ret = ww_mutex_lock(&lock->mutex, &ctx->ww_ctx);
318 		list_add(&lock->head, &ctx->locked);
327 		ctx->contended = lock;
328 		ctx->stack_depot = __drm_stack_depot_save();
336  * @ctx: the acquire context
346 int drm_modeset_backoff(struct drm_modeset_acquire_ctx *ctx)
348 	struct drm_modeset_lock *contended = ctx->contended;
350 	ctx->contended = NULL;
351 	ctx->stack_depot = 0;
356 	drm_modeset_drop_locks(ctx);
358 	return modeset_lock(contended, ctx, ctx->interruptible, true);
377  * @ctx: acquire ctx
379  * If @ctx is not NULL, then its ww acquire context is used and the
385  * If the @ctx is not NULL and initialized with
389  * If @ctx is NULL then the function call behaves like a normal,
393 		struct drm_modeset_acquire_ctx *ctx)
395 	if (ctx)
396 		return modeset_lock(lock, ctx, ctx->interruptible, false);
432  * @ctx: lock acquisition context
440  * @ctx.
443  * drm_modeset_drop_locks() function on @ctx.
450 			     struct drm_modeset_acquire_ctx *ctx)
457 	ret = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx);
462 		ret = drm_modeset_lock(&crtc->mutex, ctx);
468 		ret = drm_modeset_lock(&plane->mutex, ctx);
474 		ret = drm_modeset_lock(&privobj->lock, ctx);