diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl index 00f1c25e53df..efef63717ef6 100644 --- a/Documentation/DocBook/drm.tmpl +++ b/Documentation/DocBook/drm.tmpl @@ -1791,6 +1791,12 @@ void intel_crt_init(struct drm_device *dev) KMS API Functions !Edrivers/gpu/drm/drm_crtc.c + + KMS Locking +!Pdrivers/gpu/drm/drm_modeset_lock.c kms locking +!Iinclude/drm/drm_modeset_lock.h +!Edrivers/gpu/drm/drm_modeset_lock.c + diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index 863db8415c22..dd2ba4269740 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -13,7 +13,8 @@ drm-y := drm_auth.o drm_buffer.o drm_bufs.o drm_cache.o \ drm_crtc.o drm_modes.o drm_edid.o \ drm_info.o drm_debugfs.o drm_encoder_slave.o \ drm_trace_points.o drm_global.o drm_prime.o \ - drm_rect.o drm_vma_manager.o drm_flip_work.o + drm_rect.o drm_vma_manager.o drm_flip_work.o \ + drm_modeset_lock.o drm-$(CONFIG_COMPAT) += drm_ioc32.o drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index f3b98d4b6f46..43735f38cd17 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -37,6 +37,7 @@ #include #include #include +#include #include "drm_crtc_internal.h" @@ -50,14 +51,42 @@ */ void drm_modeset_lock_all(struct drm_device *dev) { - struct drm_crtc *crtc; + struct drm_mode_config *config = &dev->mode_config; + struct drm_modeset_acquire_ctx *ctx; + int ret; - mutex_lock(&dev->mode_config.mutex); + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); + if (WARN_ON(!ctx)) + return; - mutex_lock(&dev->mode_config.connection_mutex); + mutex_lock(&config->mutex); - list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) - mutex_lock_nest_lock(&crtc->mutex, &dev->mode_config.mutex); + drm_modeset_acquire_init(ctx, 0); + +retry: + ret = drm_modeset_lock(&config->connection_mutex, ctx); + if (ret) + goto fail; + ret = drm_modeset_lock_all_crtcs(dev, ctx); + if (ret) + goto fail; + + WARN_ON(config->acquire_ctx); + + /* now we hold the locks, so now that it is safe, stash the + * ctx for drm_modeset_unlock_all(): + */ + config->acquire_ctx = ctx; + + drm_warn_on_modeset_not_all_locked(dev); + + return; + +fail: + if (ret == -EDEADLK) { + drm_modeset_backoff(ctx); + goto retry; + } } EXPORT_SYMBOL(drm_modeset_lock_all); @@ -69,12 +98,17 @@ EXPORT_SYMBOL(drm_modeset_lock_all); */ void drm_modeset_unlock_all(struct drm_device *dev) { - struct drm_crtc *crtc; + struct drm_mode_config *config = &dev->mode_config; + struct drm_modeset_acquire_ctx *ctx = config->acquire_ctx; - list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) - mutex_unlock(&crtc->mutex); + if (WARN_ON(!ctx)) + return; - mutex_unlock(&dev->mode_config.connection_mutex); + config->acquire_ctx = NULL; + drm_modeset_drop_locks(ctx); + drm_modeset_acquire_fini(ctx); + + kfree(ctx); mutex_unlock(&dev->mode_config.mutex); } @@ -95,9 +129,9 @@ void drm_warn_on_modeset_not_all_locked(struct drm_device *dev) return; list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) - WARN_ON(!mutex_is_locked(&crtc->mutex)); + WARN_ON(!drm_modeset_is_locked(&crtc->mutex)); - WARN_ON(!mutex_is_locked(&dev->mode_config.connection_mutex)); + WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex)); WARN_ON(!mutex_is_locked(&dev->mode_config.mutex)); } EXPORT_SYMBOL(drm_warn_on_modeset_not_all_locked); @@ -671,6 +705,8 @@ void drm_framebuffer_remove(struct drm_framebuffer *fb) } EXPORT_SYMBOL(drm_framebuffer_remove); +DEFINE_WW_CLASS(crtc_ww_class); + /** * drm_crtc_init_with_planes - Initialise a new CRTC object with * specified primary and cursor planes. @@ -690,6 +726,7 @@ int drm_crtc_init_with_planes(struct drm_device *dev, struct drm_crtc *crtc, void *cursor, const struct drm_crtc_funcs *funcs) { + struct drm_mode_config *config = &dev->mode_config; int ret; crtc->dev = dev; @@ -697,8 +734,9 @@ int drm_crtc_init_with_planes(struct drm_device *dev, struct drm_crtc *crtc, crtc->invert_dimensions = false; drm_modeset_lock_all(dev); - mutex_init(&crtc->mutex); - mutex_lock_nest_lock(&crtc->mutex, &dev->mode_config.mutex); + drm_modeset_lock_init(&crtc->mutex); + /* dropped by _unlock_all(): */ + drm_modeset_lock(&crtc->mutex, config->acquire_ctx); ret = drm_mode_object_get(dev, &crtc->base, DRM_MODE_OBJECT_CRTC); if (ret) @@ -706,8 +744,8 @@ int drm_crtc_init_with_planes(struct drm_device *dev, struct drm_crtc *crtc, crtc->base.properties = &crtc->properties; - list_add_tail(&crtc->head, &dev->mode_config.crtc_list); - dev->mode_config.num_crtc++; + list_add_tail(&crtc->head, &config->crtc_list); + config->num_crtc++; crtc->primary = primary; if (primary) @@ -735,6 +773,8 @@ void drm_crtc_cleanup(struct drm_crtc *crtc) kfree(crtc->gamma_store); crtc->gamma_store = NULL; + drm_modeset_lock_fini(&crtc->mutex); + drm_mode_object_put(dev, &crtc->base); list_del(&crtc->head); dev->mode_config.num_crtc--; @@ -1798,7 +1838,7 @@ int drm_mode_getconnector(struct drm_device *dev, void *data, DRM_DEBUG_KMS("[CONNECTOR:%d:?]\n", out_resp->connector_id); mutex_lock(&dev->mode_config.mutex); - mutex_lock(&dev->mode_config.connection_mutex); + drm_modeset_lock(&dev->mode_config.connection_mutex, NULL); connector = drm_connector_find(dev, out_resp->connector_id); if (!connector) { @@ -1897,7 +1937,7 @@ int drm_mode_getconnector(struct drm_device *dev, void *data, out_resp->count_encoders = encoders_count; out: - mutex_unlock(&dev->mode_config.connection_mutex); + drm_modeset_unlock(&dev->mode_config.connection_mutex); mutex_unlock(&dev->mode_config.mutex); return ret; @@ -2481,7 +2521,7 @@ static int drm_mode_cursor_common(struct drm_device *dev, return -ENOENT; } - mutex_lock(&crtc->mutex); + drm_modeset_lock(&crtc->mutex, NULL); if (req->flags & DRM_MODE_CURSOR_BO) { if (!crtc->funcs->cursor_set && !crtc->funcs->cursor_set2) { ret = -ENXIO; @@ -2505,7 +2545,7 @@ static int drm_mode_cursor_common(struct drm_device *dev, } } out: - mutex_unlock(&crtc->mutex); + drm_modeset_unlock(&crtc->mutex); return ret; @@ -4198,7 +4238,7 @@ int drm_mode_page_flip_ioctl(struct drm_device *dev, if (!crtc) return -ENOENT; - mutex_lock(&crtc->mutex); + drm_modeset_lock(&crtc->mutex, NULL); if (crtc->primary->fb == NULL) { /* The framebuffer is currently unbound, presumably * due to a hotplug event, that userspace has not @@ -4282,7 +4322,7 @@ out: drm_framebuffer_unreference(fb); if (old_fb) drm_framebuffer_unreference(old_fb); - mutex_unlock(&crtc->mutex); + drm_modeset_unlock(&crtc->mutex); return ret; } @@ -4647,7 +4687,7 @@ EXPORT_SYMBOL(drm_format_vert_chroma_subsampling); void drm_mode_config_init(struct drm_device *dev) { mutex_init(&dev->mode_config.mutex); - mutex_init(&dev->mode_config.connection_mutex); + drm_modeset_lock_init(&dev->mode_config.connection_mutex); mutex_init(&dev->mode_config.idr_mutex); mutex_init(&dev->mode_config.fb_lock); INIT_LIST_HEAD(&dev->mode_config.fb_list); @@ -4747,5 +4787,6 @@ void drm_mode_config_cleanup(struct drm_device *dev) } idr_destroy(&dev->mode_config.crtc_idr); + drm_modeset_lock_fini(&dev->mode_config.connection_mutex); } EXPORT_SYMBOL(drm_mode_config_cleanup); diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c index b55d27c872f6..eb1c062e04b2 100644 --- a/drivers/gpu/drm/drm_crtc_helper.c +++ b/drivers/gpu/drm/drm_crtc_helper.c @@ -89,8 +89,7 @@ bool drm_helper_encoder_in_use(struct drm_encoder *encoder) struct drm_device *dev = encoder->dev; WARN_ON(!mutex_is_locked(&dev->mode_config.mutex)); - WARN_ON(!mutex_is_locked(&dev->mode_config.connection_mutex)); - + WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex)); list_for_each_entry(connector, &dev->mode_config.connector_list, head) if (connector->encoder == encoder) return true; diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 1ddc17464250..43329cee299f 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -331,6 +331,10 @@ static bool drm_fb_helper_force_kernel_mode(void) if (dev->switch_power_state == DRM_SWITCH_POWER_OFF) continue; + /* NOTE: we use lockless flag below to avoid grabbing other + * modeset locks. So just trylock the underlying mutex + * directly: + */ if (!mutex_trylock(&dev->mode_config.mutex)) { error = true; continue; diff --git a/drivers/gpu/drm/drm_modeset_lock.c b/drivers/gpu/drm/drm_modeset_lock.c new file mode 100644 index 000000000000..7c2497dea1e9 --- /dev/null +++ b/drivers/gpu/drm/drm_modeset_lock.c @@ -0,0 +1,247 @@ +/* + * Copyright (C) 2014 Red Hat + * Author: Rob Clark + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + */ + +#include +#include +#include + +/** + * DOC: kms locking + * + * As KMS moves toward more fine grained locking, and atomic ioctl where + * userspace can indirectly control locking order, it becomes necessary + * to use ww_mutex and acquire-contexts to avoid deadlocks. But because + * the locking is more distributed around the driver code, we want a bit + * of extra utility/tracking out of our acquire-ctx. This is provided + * by drm_modeset_lock / drm_modeset_acquire_ctx. + * + * For basic principles of ww_mutex, see: Documentation/ww-mutex-design.txt + * + * The basic usage pattern is to: + * + * drm_modeset_acquire_init(&ctx) + * retry: + * foreach (lock in random_ordered_set_of_locks) { + * ret = drm_modeset_lock(lock, &ctx) + * if (ret == -EDEADLK) { + * drm_modeset_backoff(&ctx); + * goto retry; + * } + * } + * + * ... do stuff ... + * + * drm_modeset_drop_locks(&ctx); + * drm_modeset_acquire_fini(&ctx); + */ + + +/** + * drm_modeset_acquire_init - initialize acquire context + * @ctx: the acquire context + * @flags: for future + */ +void drm_modeset_acquire_init(struct drm_modeset_acquire_ctx *ctx, + uint32_t flags) +{ + ww_acquire_init(&ctx->ww_ctx, &crtc_ww_class); + INIT_LIST_HEAD(&ctx->locked); +} +EXPORT_SYMBOL(drm_modeset_acquire_init); + +/** + * drm_modeset_acquire_fini - cleanup acquire context + * @ctx: the acquire context + */ +void drm_modeset_acquire_fini(struct drm_modeset_acquire_ctx *ctx) +{ + ww_acquire_fini(&ctx->ww_ctx); +} +EXPORT_SYMBOL(drm_modeset_acquire_fini); + +/** + * drm_modeset_drop_locks - drop all locks + * @ctx: the acquire context + * + * Drop all locks currently held against this acquire context. + */ +void drm_modeset_drop_locks(struct drm_modeset_acquire_ctx *ctx) +{ + WARN_ON(ctx->contended); + while (!list_empty(&ctx->locked)) { + struct drm_modeset_lock *lock; + + lock = list_first_entry(&ctx->locked, + struct drm_modeset_lock, head); + + drm_modeset_unlock(lock); + } +} +EXPORT_SYMBOL(drm_modeset_drop_locks); + +static inline int modeset_lock(struct drm_modeset_lock *lock, + struct drm_modeset_acquire_ctx *ctx, + bool interruptible, bool slow) +{ + int ret; + + WARN_ON(ctx->contended); + + if (interruptible && slow) { + ret = ww_mutex_lock_slow_interruptible(&lock->mutex, &ctx->ww_ctx); + } else if (interruptible) { + ret = ww_mutex_lock_interruptible(&lock->mutex, &ctx->ww_ctx); + } else if (slow) { + ww_mutex_lock_slow(&lock->mutex, &ctx->ww_ctx); + ret = 0; + } else { + ret = ww_mutex_lock(&lock->mutex, &ctx->ww_ctx); + } + if (!ret) { + WARN_ON(!list_empty(&lock->head)); + list_add(&lock->head, &ctx->locked); + } else if (ret == -EALREADY) { + /* we already hold the lock.. this is fine. For atomic + * we will need to be able to drm_modeset_lock() things + * without having to keep track of what is already locked + * or not. + */ + ret = 0; + } else if (ret == -EDEADLK) { + ctx->contended = lock; + } + + return ret; +} + +static int modeset_backoff(struct drm_modeset_acquire_ctx *ctx, + bool interruptible) +{ + struct drm_modeset_lock *contended = ctx->contended; + + ctx->contended = NULL; + + if (WARN_ON(!contended)) + return 0; + + drm_modeset_drop_locks(ctx); + + return modeset_lock(contended, ctx, interruptible, true); +} + +/** + * drm_modeset_backoff - deadlock avoidance backoff + * @ctx: the acquire context + * + * If deadlock is detected (ie. drm_modeset_lock() returns -EDEADLK), + * you must call this function to drop all currently held locks and + * block until the contended lock becomes available. + */ +void drm_modeset_backoff(struct drm_modeset_acquire_ctx *ctx) +{ + modeset_backoff(ctx, false); +} +EXPORT_SYMBOL(drm_modeset_backoff); + +/** + * drm_modeset_backoff_interruptible - deadlock avoidance backoff + * @ctx: the acquire context + * + * Interruptible version of drm_modeset_backoff() + */ +int drm_modeset_backoff_interruptible(struct drm_modeset_acquire_ctx *ctx) +{ + return modeset_backoff(ctx, true); +} +EXPORT_SYMBOL(drm_modeset_backoff_interruptible); + +/** + * drm_modeset_lock - take modeset lock + * @lock: lock to take + * @ctx: acquire ctx + * + * If ctx is not NULL, then its ww acquire context is used and the + * lock will be tracked by the context and can be released by calling + * drm_modeset_drop_locks(). If -EDEADLK is returned, this means a + * deadlock scenario has been detected and it is an error to attempt + * to take any more locks without first calling drm_modeset_backoff(). + */ +int drm_modeset_lock(struct drm_modeset_lock *lock, + struct drm_modeset_acquire_ctx *ctx) +{ + if (ctx) + return modeset_lock(lock, ctx, false, false); + + ww_mutex_lock(&lock->mutex, NULL); + return 0; +} +EXPORT_SYMBOL(drm_modeset_lock); + +/** + * drm_modeset_lock_interruptible - take modeset lock + * @lock: lock to take + * @ctx: acquire ctx + * + * Interruptible version of drm_modeset_lock() + */ +int drm_modeset_lock_interruptible(struct drm_modeset_lock *lock, + struct drm_modeset_acquire_ctx *ctx) +{ + if (ctx) + return modeset_lock(lock, ctx, true, false); + + return ww_mutex_lock_interruptible(&lock->mutex, NULL); +} +EXPORT_SYMBOL(drm_modeset_lock_interruptible); + +/** + * drm_modeset_unlock - drop modeset lock + * @lock: lock to release + */ +void drm_modeset_unlock(struct drm_modeset_lock *lock) +{ + list_del_init(&lock->head); + ww_mutex_unlock(&lock->mutex); +} +EXPORT_SYMBOL(drm_modeset_unlock); + +/* Temporary.. until we have sufficiently fine grained locking, there + * are a couple scenarios where it is convenient to grab all crtc locks. + * It is planned to remove this: + */ +int drm_modeset_lock_all_crtcs(struct drm_device *dev, + struct drm_modeset_acquire_ctx *ctx) +{ + struct drm_mode_config *config = &dev->mode_config; + struct drm_crtc *crtc; + int ret = 0; + + list_for_each_entry(crtc, &config->crtc_list, head) { + ret = drm_modeset_lock(&crtc->mutex, ctx); + if (ret) + return ret; + } + + return 0; +} +EXPORT_SYMBOL(drm_modeset_lock_all_crtcs); diff --git a/drivers/gpu/drm/drm_plane_helper.c b/drivers/gpu/drm/drm_plane_helper.c index f3e0a23abf4e..1b15643b4586 100644 --- a/drivers/gpu/drm/drm_plane_helper.c +++ b/drivers/gpu/drm/drm_plane_helper.c @@ -60,7 +60,7 @@ static int get_connectors_for_crtc(struct drm_crtc *crtc, * need to grab the connection_mutex here to be able to make these * checks. */ - WARN_ON(!mutex_is_locked(&dev->mode_config.connection_mutex)); + WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex)); list_for_each_entry(connector, &dev->mode_config.connector_list, head) if (connector->encoder && connector->encoder->crtc == crtc) { diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c index 1fc91df58296..5a045d3bd77e 100644 --- a/drivers/gpu/drm/i915/intel_crt.c +++ b/drivers/gpu/drm/i915/intel_crt.c @@ -630,6 +630,7 @@ intel_crt_detect(struct drm_connector *connector, bool force) enum intel_display_power_domain power_domain; enum drm_connector_status status; struct intel_load_detect_pipe tmp; + struct drm_modeset_acquire_ctx ctx; intel_runtime_pm_get(dev_priv); @@ -673,12 +674,12 @@ intel_crt_detect(struct drm_connector *connector, bool force) } /* for pre-945g platforms use load detect */ - if (intel_get_load_detect_pipe(connector, NULL, &tmp)) { + if (intel_get_load_detect_pipe(connector, NULL, &tmp, &ctx)) { if (intel_crt_detect_ddc(connector)) status = connector_status_connected; else status = intel_crt_load_detect(crt); - intel_release_load_detect_pipe(connector, &tmp); + intel_release_load_detect_pipe(connector, &tmp, &ctx); } else status = connector_status_unknown; diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index c2976ade823f..1ce4ad4626e4 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -2576,7 +2576,7 @@ void intel_display_handle_reset(struct drm_device *dev) for_each_crtc(dev, crtc) { struct intel_crtc *intel_crtc = to_intel_crtc(crtc); - mutex_lock(&crtc->mutex); + drm_modeset_lock(&crtc->mutex, NULL); /* * FIXME: Once we have proper support for primary planes (and * disabling them without disabling the entire crtc) allow again @@ -2587,7 +2587,7 @@ void intel_display_handle_reset(struct drm_device *dev) crtc->primary->fb, crtc->x, crtc->y); - mutex_unlock(&crtc->mutex); + drm_modeset_unlock(&crtc->mutex); } } @@ -8307,7 +8307,8 @@ mode_fits_in_fbdev(struct drm_device *dev, bool intel_get_load_detect_pipe(struct drm_connector *connector, struct drm_display_mode *mode, - struct intel_load_detect_pipe *old) + struct intel_load_detect_pipe *old, + struct drm_modeset_acquire_ctx *ctx) { struct intel_crtc *intel_crtc; struct intel_encoder *intel_encoder = @@ -8317,13 +8318,19 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector, struct drm_crtc *crtc = NULL; struct drm_device *dev = encoder->dev; struct drm_framebuffer *fb; - int i = -1; + struct drm_mode_config *config = &dev->mode_config; + int ret, i = -1; DRM_DEBUG_KMS("[CONNECTOR:%d:%s], [ENCODER:%d:%s]\n", connector->base.id, connector->name, encoder->base.id, encoder->name); - mutex_lock(&dev->mode_config.connection_mutex); + drm_modeset_acquire_init(ctx, 0); + +retry: + ret = drm_modeset_lock(&config->connection_mutex, ctx); + if (ret) + goto fail_unlock; /* * Algorithm gets a little messy: @@ -8339,7 +8346,9 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector, if (encoder->crtc) { crtc = encoder->crtc; - mutex_lock(&crtc->mutex); + ret = drm_modeset_lock(&crtc->mutex, ctx); + if (ret) + goto fail_unlock; old->dpms_mode = connector->dpms; old->load_detect_temp = false; @@ -8367,10 +8376,12 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector, */ if (!crtc) { DRM_DEBUG_KMS("no pipe available for load-detect\n"); - goto fail_unlock_connector; + goto fail_unlock; } - mutex_lock(&crtc->mutex); + ret = drm_modeset_lock(&crtc->mutex, ctx); + if (ret) + goto fail_unlock; intel_encoder->new_crtc = to_intel_crtc(crtc); to_intel_connector(connector)->new_encoder = intel_encoder; @@ -8420,15 +8431,21 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector, intel_crtc->new_config = &intel_crtc->config; else intel_crtc->new_config = NULL; - mutex_unlock(&crtc->mutex); -fail_unlock_connector: - mutex_unlock(&dev->mode_config.connection_mutex); +fail_unlock: + if (ret == -EDEADLK) { + drm_modeset_backoff(ctx); + goto retry; + } + + drm_modeset_drop_locks(ctx); + drm_modeset_acquire_fini(ctx); return false; } void intel_release_load_detect_pipe(struct drm_connector *connector, - struct intel_load_detect_pipe *old) + struct intel_load_detect_pipe *old, + struct drm_modeset_acquire_ctx *ctx) { struct intel_encoder *intel_encoder = intel_attached_encoder(connector); @@ -8452,8 +8469,7 @@ void intel_release_load_detect_pipe(struct drm_connector *connector, drm_framebuffer_unreference(old->release_fb); } - mutex_unlock(&crtc->mutex); - mutex_unlock(&connector->dev->mode_config.connection_mutex); + goto unlock; return; } @@ -8461,8 +8477,9 @@ void intel_release_load_detect_pipe(struct drm_connector *connector, if (old->dpms_mode != DRM_MODE_DPMS_ON) connector->funcs->dpms(connector, old->dpms_mode); - mutex_unlock(&crtc->mutex); - mutex_unlock(&connector->dev->mode_config.connection_mutex); +unlock: + drm_modeset_drop_locks(ctx); + drm_modeset_acquire_fini(ctx); } static int i9xx_pll_refclk(struct drm_device *dev, @@ -10995,7 +11012,7 @@ enum pipe intel_get_pipe_from_connector(struct intel_connector *connector) struct drm_encoder *encoder = connector->base.encoder; struct drm_device *dev = connector->base.dev; - WARN_ON(!mutex_is_locked(&dev->mode_config.connection_mutex)); + WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex)); if (!encoder) return INVALID_PIPE; @@ -11805,6 +11822,7 @@ static void intel_enable_pipe_a(struct drm_device *dev) struct intel_connector *connector; struct drm_connector *crt = NULL; struct intel_load_detect_pipe load_detect_temp; + struct drm_modeset_acquire_ctx ctx; /* We can't just switch on the pipe A, we need to set things up with a * proper mode and output configuration. As a gross hack, enable pipe A @@ -11821,8 +11839,8 @@ static void intel_enable_pipe_a(struct drm_device *dev) if (!crt) return; - if (intel_get_load_detect_pipe(crt, NULL, &load_detect_temp)) - intel_release_load_detect_pipe(crt, &load_detect_temp); + if (intel_get_load_detect_pipe(crt, NULL, &load_detect_temp, &ctx)) + intel_release_load_detect_pipe(crt, &load_detect_temp, &ctx); } diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index d01bb430b5bc..2d5d9b010073 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -1154,7 +1154,7 @@ static void edp_panel_vdd_off_sync(struct intel_dp *intel_dp) u32 pp; u32 pp_stat_reg, pp_ctrl_reg; - WARN_ON(!mutex_is_locked(&dev->mode_config.connection_mutex)); + WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex)); if (!intel_dp->want_panel_vdd && edp_have_panel_vdd(intel_dp)) { struct intel_digital_port *intel_dig_port = @@ -1191,9 +1191,9 @@ static void edp_panel_vdd_work(struct work_struct *__work) struct intel_dp, panel_vdd_work); struct drm_device *dev = intel_dp_to_dev(intel_dp); - mutex_lock(&dev->mode_config.connection_mutex); + drm_modeset_lock(&dev->mode_config.connection_mutex, NULL); edp_panel_vdd_off_sync(intel_dp); - mutex_unlock(&dev->mode_config.connection_mutex); + drm_modeset_unlock(&dev->mode_config.connection_mutex); } static void edp_panel_vdd_off(struct intel_dp *intel_dp, bool sync) @@ -3666,9 +3666,9 @@ void intel_dp_encoder_destroy(struct drm_encoder *encoder) drm_encoder_cleanup(encoder); if (is_edp(intel_dp)) { cancel_delayed_work_sync(&intel_dp->panel_vdd_work); - mutex_lock(&dev->mode_config.connection_mutex); + drm_modeset_lock(&dev->mode_config.connection_mutex, NULL); edp_panel_vdd_off_sync(intel_dp); - mutex_unlock(&dev->mode_config.connection_mutex); + drm_modeset_unlock(&dev->mode_config.connection_mutex); } kfree(intel_dig_port); } @@ -4247,9 +4247,9 @@ intel_dp_init_connector(struct intel_digital_port *intel_dig_port, drm_dp_aux_unregister(&intel_dp->aux); if (is_edp(intel_dp)) { cancel_delayed_work_sync(&intel_dp->panel_vdd_work); - mutex_lock(&dev->mode_config.connection_mutex); + drm_modeset_lock(&dev->mode_config.connection_mutex, NULL); edp_panel_vdd_off_sync(intel_dp); - mutex_unlock(&dev->mode_config.connection_mutex); + drm_modeset_unlock(&dev->mode_config.connection_mutex); } drm_sysfs_connector_remove(connector); drm_connector_cleanup(connector); diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index f1d5897c96cd..0de04983501e 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -748,9 +748,11 @@ void vlv_wait_port_ready(struct drm_i915_private *dev_priv, struct intel_digital_port *dport); bool intel_get_load_detect_pipe(struct drm_connector *connector, struct drm_display_mode *mode, - struct intel_load_detect_pipe *old); + struct intel_load_detect_pipe *old, + struct drm_modeset_acquire_ctx *ctx); void intel_release_load_detect_pipe(struct drm_connector *connector, - struct intel_load_detect_pipe *old); + struct intel_load_detect_pipe *old, + struct drm_modeset_acquire_ctx *ctx); int intel_pin_and_fence_fb_obj(struct drm_device *dev, struct drm_i915_gem_object *obj, struct intel_engine_cs *pipelined); diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c index b812e9d39f38..2e2c71fcc9ed 100644 --- a/drivers/gpu/drm/i915/intel_opregion.c +++ b/drivers/gpu/drm/i915/intel_opregion.c @@ -410,7 +410,7 @@ static u32 asle_set_backlight(struct drm_device *dev, u32 bclp) if (bclp > 255) return ASLC_BACKLIGHT_FAILED; - mutex_lock(&dev->mode_config.connection_mutex); + drm_modeset_lock(&dev->mode_config.connection_mutex, NULL); /* * Update backlight on all connectors that support backlight (usually @@ -421,7 +421,7 @@ static u32 asle_set_backlight(struct drm_device *dev, u32 bclp) intel_panel_set_backlight(intel_connector, bclp, 255); iowrite32(DIV_ROUND_UP(bclp * 100, 255) | ASLE_CBLV_VALID, &asle->cblv); - mutex_unlock(&dev->mode_config.connection_mutex); + drm_modeset_unlock(&dev->mode_config.connection_mutex); return 0; diff --git a/drivers/gpu/drm/i915/intel_overlay.c b/drivers/gpu/drm/i915/intel_overlay.c index e97ea33e0117..0396d1312b5c 100644 --- a/drivers/gpu/drm/i915/intel_overlay.c +++ b/drivers/gpu/drm/i915/intel_overlay.c @@ -688,7 +688,7 @@ static int intel_overlay_do_put_image(struct intel_overlay *overlay, u32 swidth, swidthsw, sheight, ostride; BUG_ON(!mutex_is_locked(&dev->struct_mutex)); - BUG_ON(!mutex_is_locked(&dev->mode_config.connection_mutex)); + BUG_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex)); BUG_ON(!overlay); ret = intel_overlay_release_old_vid(overlay); @@ -793,7 +793,7 @@ int intel_overlay_switch_off(struct intel_overlay *overlay) int ret; BUG_ON(!mutex_is_locked(&dev->struct_mutex)); - BUG_ON(!mutex_is_locked(&dev->mode_config.connection_mutex)); + BUG_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex)); ret = intel_overlay_recover_from_interrupt(overlay); if (ret != 0) diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c index d4d415665475..2e1338a5d488 100644 --- a/drivers/gpu/drm/i915/intel_panel.c +++ b/drivers/gpu/drm/i915/intel_panel.c @@ -876,12 +876,12 @@ static int intel_backlight_device_update_status(struct backlight_device *bd) struct intel_connector *connector = bl_get_data(bd); struct drm_device *dev = connector->base.dev; - mutex_lock(&dev->mode_config.connection_mutex); + drm_modeset_lock(&dev->mode_config.connection_mutex, NULL); DRM_DEBUG_KMS("updating intel_backlight, brightness=%d/%d\n", bd->props.brightness, bd->props.max_brightness); intel_panel_set_backlight(connector, bd->props.brightness, bd->props.max_brightness); - mutex_unlock(&dev->mode_config.connection_mutex); + drm_modeset_unlock(&dev->mode_config.connection_mutex); return 0; } @@ -893,9 +893,9 @@ static int intel_backlight_device_get_brightness(struct backlight_device *bd) int ret; intel_runtime_pm_get(dev_priv); - mutex_lock(&dev->mode_config.connection_mutex); + drm_modeset_lock(&dev->mode_config.connection_mutex, NULL); ret = intel_panel_get_backlight(connector); - mutex_unlock(&dev->mode_config.connection_mutex); + drm_modeset_unlock(&dev->mode_config.connection_mutex); intel_runtime_pm_put(dev_priv); return ret; diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c index d6acd6bd0bf0..1b66ddcdfb33 100644 --- a/drivers/gpu/drm/i915/intel_sprite.c +++ b/drivers/gpu/drm/i915/intel_sprite.c @@ -55,7 +55,7 @@ static bool intel_pipe_update_start(struct intel_crtc *crtc, uint32_t *start_vbl int scanline, min, max, vblank_start; DEFINE_WAIT(wait); - WARN_ON(!mutex_is_locked(&crtc->base.mutex)); + WARN_ON(!drm_modeset_is_locked(&crtc->base.mutex)); vblank_start = mode->crtc_vblank_start; if (mode->flags & DRM_MODE_FLAG_INTERLACE) diff --git a/drivers/gpu/drm/i915/intel_tv.c b/drivers/gpu/drm/i915/intel_tv.c index 25850a86d70c..67c6c9a2eb1c 100644 --- a/drivers/gpu/drm/i915/intel_tv.c +++ b/drivers/gpu/drm/i915/intel_tv.c @@ -1321,10 +1321,11 @@ intel_tv_detect(struct drm_connector *connector, bool force) if (force) { struct intel_load_detect_pipe tmp; + struct drm_modeset_acquire_ctx ctx; - if (intel_get_load_detect_pipe(connector, &mode, &tmp)) { + if (intel_get_load_detect_pipe(connector, &mode, &tmp, &ctx)) { type = intel_tv_detect_type(intel_tv, connector); - intel_release_load_detect_pipe(connector, &tmp); + intel_release_load_detect_pipe(connector, &tmp, &ctx); } else return connector_status_unknown; } else diff --git a/drivers/gpu/drm/omapdrm/omap_crtc.c b/drivers/gpu/drm/omapdrm/omap_crtc.c index e3c47a8005ff..2d28dc337cfb 100644 --- a/drivers/gpu/drm/omapdrm/omap_crtc.c +++ b/drivers/gpu/drm/omapdrm/omap_crtc.c @@ -319,13 +319,13 @@ static void page_flip_worker(struct work_struct *work) struct drm_display_mode *mode = &crtc->mode; struct drm_gem_object *bo; - mutex_lock(&crtc->mutex); + drm_modeset_lock(&crtc->mutex, NULL); omap_plane_mode_set(omap_crtc->plane, crtc, crtc->primary->fb, 0, 0, mode->hdisplay, mode->vdisplay, crtc->x << 16, crtc->y << 16, mode->hdisplay << 16, mode->vdisplay << 16, vblank_cb, crtc); - mutex_unlock(&crtc->mutex); + drm_modeset_unlock(&crtc->mutex); bo = omap_framebuffer_bo(crtc->primary->fb, 0); drm_gem_object_unreference_unlocked(bo); @@ -465,7 +465,7 @@ static void apply_worker(struct work_struct *work) * the callbacks and list modification all serialized * with respect to modesetting ioctls from userspace. */ - mutex_lock(&crtc->mutex); + drm_modeset_lock(&crtc->mutex, NULL); dispc_runtime_get(); /* @@ -510,7 +510,7 @@ static void apply_worker(struct work_struct *work) out: dispc_runtime_put(); - mutex_unlock(&crtc->mutex); + drm_modeset_unlock(&crtc->mutex); } int omap_crtc_apply(struct drm_crtc *crtc, @@ -518,7 +518,7 @@ int omap_crtc_apply(struct drm_crtc *crtc, { struct omap_crtc *omap_crtc = to_omap_crtc(crtc); - WARN_ON(!mutex_is_locked(&crtc->mutex)); + WARN_ON(!drm_modeset_is_locked(&crtc->mutex)); /* no need to queue it again if it is already queued: */ if (apply->queued) diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c index e7199b454ca0..8f3edc4710f2 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c @@ -187,7 +187,7 @@ int vmw_du_crtc_cursor_set(struct drm_crtc *crtc, struct drm_file *file_priv, * can do this since the caller in the drm core doesn't check anything * which is protected by any looks. */ - mutex_unlock(&crtc->mutex); + drm_modeset_unlock(&crtc->mutex); drm_modeset_lock_all(dev_priv->dev); /* A lot of the code assumes this */ @@ -252,7 +252,7 @@ int vmw_du_crtc_cursor_set(struct drm_crtc *crtc, struct drm_file *file_priv, ret = 0; out: drm_modeset_unlock_all(dev_priv->dev); - mutex_lock(&crtc->mutex); + drm_modeset_lock(&crtc->mutex, NULL); return ret; } @@ -273,7 +273,7 @@ int vmw_du_crtc_cursor_move(struct drm_crtc *crtc, int x, int y) * can do this since the caller in the drm core doesn't check anything * which is protected by any looks. */ - mutex_unlock(&crtc->mutex); + drm_modeset_unlock(&crtc->mutex); drm_modeset_lock_all(dev_priv->dev); vmw_cursor_update_position(dev_priv, shown, @@ -281,7 +281,7 @@ int vmw_du_crtc_cursor_move(struct drm_crtc *crtc, int x, int y) du->cursor_y + du->hotspot_y); drm_modeset_unlock_all(dev_priv->dev); - mutex_lock(&crtc->mutex); + drm_modeset_lock(&crtc->mutex, NULL); return 0; } diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 76ccaabd0418..475ca5cf3c20 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -1186,11 +1186,6 @@ static inline int drm_device_is_unplugged(struct drm_device *dev) return ret; } -static inline bool drm_modeset_is_locked(struct drm_device *dev) -{ - return mutex_is_locked(&dev->mode_config.mutex); -} - static inline bool drm_is_render_client(const struct drm_file *file_priv) { return file_priv->minor->type == DRM_MINOR_RENDER; diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index 6c295df7b0df..a7fac5686915 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -33,6 +33,7 @@ #include #include #include +#include struct drm_device; struct drm_mode_set; @@ -205,6 +206,10 @@ struct drm_property { struct list_head enum_blob_list; }; +void drm_modeset_lock_all(struct drm_device *dev); +void drm_modeset_unlock_all(struct drm_device *dev); +void drm_warn_on_modeset_not_all_locked(struct drm_device *dev); + struct drm_crtc; struct drm_connector; struct drm_encoder; @@ -280,6 +285,7 @@ struct drm_crtc_funcs { * drm_crtc - central CRTC control structure * @dev: parent DRM device * @head: list management + * @mutex: per-CRTC locking * @base: base KMS object for ID tracking etc. * @primary: primary plane for this CRTC * @cursor: cursor plane for this CRTC @@ -314,7 +320,7 @@ struct drm_crtc { * state, ...) and a write lock for everything which can be update * without a full modeset (fb, cursor data, ...) */ - struct mutex mutex; + struct drm_modeset_lock mutex; struct drm_mode_object base; @@ -738,7 +744,8 @@ struct drm_mode_group { */ struct drm_mode_config { struct mutex mutex; /* protects configuration (mode lists etc.) */ - struct mutex connection_mutex; /* protects connector->encoder and encoder->crtc links */ + struct drm_modeset_lock connection_mutex; /* protects connector->encoder and encoder->crtc links */ + struct drm_modeset_acquire_ctx *acquire_ctx; /* for legacy _lock_all() / _unlock_all() */ struct mutex idr_mutex; /* for IDR management */ struct idr crtc_idr; /* use this idr for all IDs, fb, crtc, connector, modes - just makes life easier */ /* this is limited to one for now */ @@ -839,10 +846,6 @@ struct drm_prop_enum_list { char *name; }; -extern void drm_modeset_lock_all(struct drm_device *dev); -extern void drm_modeset_unlock_all(struct drm_device *dev); -extern void drm_warn_on_modeset_not_all_locked(struct drm_device *dev); - extern int drm_crtc_init_with_planes(struct drm_device *dev, struct drm_crtc *crtc, struct drm_plane *primary, diff --git a/include/drm/drm_modeset_lock.h b/include/drm/drm_modeset_lock.h new file mode 100644 index 000000000000..402aa7a6a058 --- /dev/null +++ b/include/drm/drm_modeset_lock.h @@ -0,0 +1,126 @@ +/* + * Copyright (C) 2014 Red Hat + * Author: Rob Clark + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + */ + +#ifndef DRM_MODESET_LOCK_H_ +#define DRM_MODESET_LOCK_H_ + +#include + +struct drm_modeset_lock; + +/** + * drm_modeset_acquire_ctx - locking context (see ww_acquire_ctx) + * @ww_ctx: base acquire ctx + * @contended: used internally for -EDEADLK handling + * @locked: list of held locks + * + * Each thread competing for a set of locks must use one acquire + * ctx. And if any lock fxn returns -EDEADLK, it must backoff and + * retry. + */ +struct drm_modeset_acquire_ctx { + + struct ww_acquire_ctx ww_ctx; + + /** + * Contended lock: if a lock is contended you should only call + * drm_modeset_backoff() which drops locks and slow-locks the + * contended lock. + */ + struct drm_modeset_lock *contended; + + /** + * list of held locks (drm_modeset_lock) + */ + struct list_head locked; +}; + +/** + * drm_modeset_lock - used for locking modeset resources. + * @mutex: resource locking + * @head: used to hold it's place on state->locked list when + * part of an atomic update + * + * Used for locking CRTCs and other modeset resources. + */ +struct drm_modeset_lock { + /** + * modeset lock + */ + struct ww_mutex mutex; + + /** + * Resources that are locked as part of an atomic update are added + * to a list (so we know what to unlock at the end). + */ + struct list_head head; +}; + +extern struct ww_class crtc_ww_class; + +void drm_modeset_acquire_init(struct drm_modeset_acquire_ctx *ctx, + uint32_t flags); +void drm_modeset_acquire_fini(struct drm_modeset_acquire_ctx *ctx); +void drm_modeset_drop_locks(struct drm_modeset_acquire_ctx *ctx); +void drm_modeset_backoff(struct drm_modeset_acquire_ctx *ctx); +int drm_modeset_backoff_interruptible(struct drm_modeset_acquire_ctx *ctx); + +/** + * drm_modeset_lock_init - initialize lock + * @lock: lock to init + */ +static inline void drm_modeset_lock_init(struct drm_modeset_lock *lock) +{ + ww_mutex_init(&lock->mutex, &crtc_ww_class); + INIT_LIST_HEAD(&lock->head); +} + +/** + * drm_modeset_lock_fini - cleanup lock + * @lock: lock to cleanup + */ +static inline void drm_modeset_lock_fini(struct drm_modeset_lock *lock) +{ + WARN_ON(!list_empty(&lock->head)); +} + +/** + * drm_modeset_is_locked - equivalent to mutex_is_locked() + * @lock: lock to check + */ +static inline bool drm_modeset_is_locked(struct drm_modeset_lock *lock) +{ + return ww_mutex_is_locked(&lock->mutex); +} + +int drm_modeset_lock(struct drm_modeset_lock *lock, + struct drm_modeset_acquire_ctx *ctx); +int drm_modeset_lock_interruptible(struct drm_modeset_lock *lock, + struct drm_modeset_acquire_ctx *ctx); +void drm_modeset_unlock(struct drm_modeset_lock *lock); + +struct drm_device; +int drm_modeset_lock_all_crtcs(struct drm_device *dev, + struct drm_modeset_acquire_ctx *ctx); + +#endif /* DRM_MODESET_LOCK_H_ */