For atomic, it will be quite necessary to not need to care so much about locking order. And 'state' gives us a convenient place to stash a ww_ctx for any sort of update that needs to grab multiple crtc locks.
Because we will want to eventually make locking even more fine grained (giving locks to planes, connectors, etc), split out drm_modeset_lock and drm_modeset_acquire_ctx to track acquired locks.
Atomic will use this to keep track of which locks have been acquired in a transaction.
Signed-off-by: Rob Clark robdclark@gmail.com --- drivers/gpu/drm/Makefile | 2 +- drivers/gpu/drm/drm_crtc.c | 87 +++++++++++----- drivers/gpu/drm/drm_crtc_helper.c | 3 +- drivers/gpu/drm/drm_fb_helper.c | 4 + drivers/gpu/drm/drm_modeset_lock.c | 187 +++++++++++++++++++++++++++++++++++ drivers/gpu/drm/drm_plane_helper.c | 2 +- drivers/gpu/drm/i915/intel_crt.c | 5 +- drivers/gpu/drm/i915/intel_display.c | 58 +++++++---- drivers/gpu/drm/i915/intel_drv.h | 6 +- drivers/gpu/drm/i915/intel_sprite.c | 2 +- drivers/gpu/drm/i915/intel_tv.c | 5 +- drivers/gpu/drm/omapdrm/omap_crtc.c | 10 +- drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 8 +- include/drm/drmP.h | 5 - include/drm/drm_crtc.h | 15 +-- include/drm/drm_modeset_lock.h | 139 ++++++++++++++++++++++++++ include/uapi/drm/drm_mode.h | 3 + 17 files changed, 468 insertions(+), 73 deletions(-) create mode 100644 drivers/gpu/drm/drm_modeset_lock.c create mode 100644 include/drm/drm_modeset_lock.h
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index 48e38ba..bf4c12d 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -14,7 +14,7 @@ drm-y := drm_auth.o drm_buffer.o drm_bufs.o drm_cache.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_plane_helper.o + drm_plane_helper.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 de1520c..cf622f6 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -37,8 +37,8 @@ #include <drm/drm_crtc.h> #include <drm/drm_edid.h> #include <drm/drm_fourcc.h> +#include <drm/drm_modeset_lock.h>
-#include "drm_crtc_internal.h"
/** * drm_modeset_lock_all - take all modeset locks @@ -50,14 +50,42 @@ */ 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, false, false); + +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 +97,18 @@ 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; + + config->acquire_ctx = NULL; + drm_modeset_drop_locks(ctx); + ww_acquire_fini(&ctx->ww_ctx); + drm_modeset_acquire_fini(ctx);
- mutex_unlock(&dev->mode_config.connection_mutex); + 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); @@ -677,6 +711,8 @@ 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. @@ -696,6 +732,7 @@ 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; @@ -703,8 +740,9 @@ 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) @@ -712,8 +750,8 @@ 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) @@ -741,6 +779,8 @@ 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--; @@ -1804,7 +1844,7 @@ 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) { @@ -1903,7 +1943,7 @@ 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; @@ -2487,7 +2527,7 @@ 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; @@ -2511,7 +2551,7 @@ static int drm_mode_cursor_common(struct drm_device *dev, } } out: - mutex_unlock(&crtc->mutex); + drm_modeset_unlock(&crtc->mutex);
return ret;
@@ -4195,7 +4235,7 @@ 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 @@ -4279,7 +4319,7 @@ out: drm_framebuffer_unreference(fb); if (old_fb) drm_framebuffer_unreference(old_fb); - mutex_unlock(&crtc->mutex); + drm_modeset_unlock(&crtc->mutex);
return ret; } @@ -4644,7 +4684,7 @@ 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); @@ -4744,5 +4784,6 @@ 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 5b93caf..4eaded8 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 1e28ba6..25f687d 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -355,6 +355,10 @@ 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 0000000..6580d6c --- /dev/null +++ b/drivers/gpu/drm/drm_modeset_lock.c @@ -0,0 +1,187 @@ +/* + * Copyright (C) 2014 Red Hat + * Author: Rob Clark robdclark@gmail.com + * + * 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 <drm/drmP.h> +#include <drm/drm_crtc.h> +#include <drm/drm_modeset_lock.h> + + +void drm_modeset_acquire_init(struct drm_modeset_acquire_ctx *ctx, + bool nolock, bool nonblock) +{ + ww_acquire_init(&ctx->ww_ctx, &crtc_ww_class); + INIT_LIST_HEAD(&ctx->locked); + mutex_init(&ctx->mutex); + ctx->nolock = nolock; + ctx->nonblock = nonblock; +} +EXPORT_SYMBOL(drm_modeset_acquire_init); + +void drm_modeset_acquire_fini(struct drm_modeset_acquire_ctx *ctx) +{ + WARN_ON(ctx->contended); + /* + * NOTE: it is intentional that ww_acquire_fini() is not called + * here.. due to the way lock handover works in drm_atomic + */ + mutex_destroy(&ctx->mutex); +} +EXPORT_SYMBOL(drm_modeset_acquire_fini); + +void drm_modeset_drop_locks(struct drm_modeset_acquire_ctx *ctx) +{ + WARN_ON(ctx->contended); + mutex_lock(&ctx->mutex); + 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); + } + mutex_unlock(&ctx->mutex); +} +EXPORT_SYMBOL(drm_modeset_drop_locks); + +static int modeset_lock(struct drm_modeset_lock *lock, + struct drm_modeset_acquire_ctx *ctx, + bool interruptible, bool slow) +{ + int ret; + + if (ctx->nolock) + return 0; + + WARN_ON(ctx->frozen); /* all locks should be held by now! */ + WARN_ON(ctx->contended); + +retry: + 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) { + if (lock->atomic_pending) { + /* some other pending update with dropped locks */ + ww_mutex_unlock(&lock->mutex); + if (ctx->nonblock) + return -EBUSY; + wait_event(lock->event, !lock->atomic_pending); + goto retry; + } + lock->atomic_pending = true; + WARN_ON(!list_empty(&lock->head)); + list_add(&lock->head, &ctx->locked); + } else if (ret == -EALREADY) { + /* we already hold the lock.. this is fine */ + ret = 0; + } else if (ret == -EDEADLK) { + ctx->contended = lock; + } + + return ret; +} + +void drm_modeset_backoff(struct drm_modeset_acquire_ctx *ctx) +{ + struct drm_modeset_lock *contended = ctx->contended; + + ctx->contended = NULL; + + if (WARN_ON(!contended)) + return; + + drm_modeset_drop_locks(ctx); + + modeset_lock(contended, ctx, false, true); +} +EXPORT_SYMBOL(drm_modeset_backoff); + +/** + * drm_modeset_lock - take modeset lock + * @lock: lock to take + * @ctx: acquire ctx + * + * If ctx is not NULL, then then it's acquire context is used + * and the lock does not need to be explicitly unlocked, it + * will be automatically unlocked when the atomic update is + * complete + */ +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); + +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); + lock->atomic_pending = false; + ww_mutex_unlock(&lock->mutex); + wake_up_all(&lock->event); +} +EXPORT_SYMBOL(drm_modeset_unlock); + +/** + * drm_modeset_lock_all_crtcs - helper to drm_modeset_lock() all CRTCs + */ +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 458d9bf..6301ec6 100644 --- a/drivers/gpu/drm/drm_plane_helper.c +++ b/drivers/gpu/drm/drm_plane_helper.c @@ -59,7 +59,7 @@ 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 22d8347..33328fc 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 5844f07..ba6cbbb 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -2363,7 +2363,7 @@ void intel_display_handle_reset(struct drm_device *dev) list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) { 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 @@ -2374,7 +2374,7 @@ 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); } }
@@ -7972,7 +7972,8 @@ 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 = @@ -7982,13 +7983,19 @@ 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, drm_get_connector_name(connector), encoder->base.id, drm_get_encoder_name(encoder));
- mutex_lock(&dev->mode_config.connection_mutex); + drm_modeset_acquire_init(ctx, false, false); + +retry: + ret = drm_modeset_lock(&config->connection_mutex, ctx); + if (ret) + goto fail_unlock;
/* * Algorithm gets a little messy: @@ -8004,7 +8011,9 @@ 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; @@ -8017,7 +8026,7 @@ bool intel_get_load_detect_pipe(struct drm_connector *connector, }
/* Find an unused one (if possible) */ - list_for_each_entry(possible_crtc, &dev->mode_config.crtc_list, head) { + list_for_each_entry(possible_crtc, &config->crtc_list, head) { i++; if (!(encoder->possible_crtcs & (1 << i))) continue; @@ -8032,10 +8041,12 @@ 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;
@@ -8085,15 +8096,22 @@ 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); + ww_acquire_fini(&ctx->ww_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); @@ -8117,8 +8135,7 @@ 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; }
@@ -8126,8 +8143,10 @@ 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); + ww_acquire_fini(&ctx->ww_ctx); + drm_modeset_acquire_fini(ctx); }
static int i9xx_pll_refclk(struct drm_device *dev, @@ -11385,6 +11404,7 @@ 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 @@ -11401,8 +11421,8 @@ 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_drv.h b/drivers/gpu/drm/i915/intel_drv.h index d8b540b..824f8ae 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -721,9 +721,11 @@ 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_ring_buffer *pipelined); diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c index 213cd58..c235546 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 e0193e8..97d9fc9 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 e3c47a8..2d28dc3 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 e7199b4..8f3edc4 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 12f10bc..a9b8a5d 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -1184,11 +1184,6 @@ 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 1bd6708..deadb32 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -33,6 +33,7 @@ #include <linux/hdmi.h> #include <drm/drm_mode.h> #include <drm/drm_fourcc.h> +#include <drm/drm_modeset_lock.h>
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 0000000..2630da3 --- /dev/null +++ b/include/drm/drm_modeset_lock.h @@ -0,0 +1,139 @@ +/* + * Copyright (C) 2014 Red Hat + * Author: Rob Clark robdclark@gmail.com + * + * 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 <linux/ww_mutex.h> + +struct drm_modeset_lock; + +struct drm_modeset_acquire_ctx { + + struct ww_acquire_ctx ww_ctx; + + bool nolock : 1; + bool nonblock : 1; + + /* just for debugging, the context is 'frozen' in drm_atomic_check() + * to catch anyone who might be trying to acquire a lock after it is + * too late. + */ + bool frozen : 1; + + /* 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 'struct drm_modeset_lock': */ + struct list_head locked; + + /* currently simply for protecting against 'locked' list manipulation + * between original thread calling atomic->end() and driver thread + * calling back drm_atomic_commit_unlocked(). + * + * Other spots are sufficiently synchronized by virtue of holding + * the lock's ww_mutex. But during the lock/resource hand-over to the + * driver thread (drop_locks()/grab_locks()), we cannot rely on this. + */ + struct mutex mutex; +}; + +/** + * drm_modeset_lock - used for locking modeset resources. + * @mutex: resource locking + * @atomic_pending: is this resource part of a still-pending + * atomic update + * @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; + + /** + * Are we busy (pending asynchronous/NONBLOCK update)? Any further + * asynchronous update will return -EBUSY if it also needs to acquire + * this lock. While a synchronous update will block until the pending + * async update completes. + * + * Drivers must ensure the update is completed before sending vblank + * event to userspace. Typically this just means don't send event + * before drm_atomic_commit_unlocked() returns. + */ + bool atomic_pending; + + /** + * 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; + + /** + * For waiting on atomic_pending locks, if not a NONBLOCK operation. + */ + wait_queue_head_t event; +}; + +extern struct ww_class crtc_ww_class; + +void drm_modeset_acquire_init(struct drm_modeset_acquire_ctx *ctx, + bool nolock, bool nonblock); +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); + +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); + init_waitqueue_head(&lock->event); +} + +static inline void drm_modeset_lock_fini(struct drm_modeset_lock *lock) +{ + WARN_ON(!list_empty(&lock->head)); +} + +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_ */ diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h index ded505e..6421edc 100644 --- a/include/uapi/drm/drm_mode.h +++ b/include/uapi/drm/drm_mode.h @@ -511,4 +511,7 @@ struct drm_mode_destroy_dumb { uint32_t handle; };
+#define DRM_MODE_ATOMIC_NONBLOCK 0x0200 +#define DRM_MODE_ATOMIC_NOLOCK 0x8000 /* only used internally */ + #endif