[PATCH 1/2] drm: convert crtc and connection_mutex to ww_mutex (v4)
Daniel Vetter
daniel at ffwll.ch
Wed Jun 4 07:47:28 PDT 2014
On Wed, Jun 04, 2014 at 10:27:25AM -0400, Rob Clark wrote:
> 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.
>
> v1: original
> v2: remove a few things not needed until atomic, for now
> v3: update for v3 of connection_mutex patch..
> v4: squash in docbook
>
> Signed-off-by: Rob Clark <robdclark at gmail.com>
Ok, only checked the kerneldoc now and found a few nitpicks. With those
fixed and presuming no bugs added to the code compared to last version
this is Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> ---
> Documentation/DocBook/drm.tmpl | 6 +
> drivers/gpu/drm/Makefile | 3 +-
> drivers/gpu/drm/drm_crtc.c | 85 +++++++++---
> drivers/gpu/drm/drm_crtc_helper.c | 3 +-
> drivers/gpu/drm/drm_fb_helper.c | 4 +
> drivers/gpu/drm/drm_modeset_lock.c | 247 ++++++++++++++++++++++++++++++++++
> drivers/gpu/drm/drm_plane_helper.c | 2 +-
> drivers/gpu/drm/i915/intel_crt.c | 5 +-
> drivers/gpu/drm/i915/intel_display.c | 56 +++++---
> drivers/gpu/drm/i915/intel_dp.c | 14 +-
> drivers/gpu/drm/i915/intel_drv.h | 6 +-
> drivers/gpu/drm/i915/intel_opregion.c | 4 +-
> drivers/gpu/drm/i915/intel_overlay.c | 4 +-
> drivers/gpu/drm/i915/intel_panel.c | 8 +-
> 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 | 123 +++++++++++++++++
> 21 files changed, 528 insertions(+), 87 deletions(-)
> create mode 100644 drivers/gpu/drm/drm_modeset_lock.c
> create mode 100644 include/drm/drm_modeset_lock.h
>
> diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl
> index 00f1c25..efef637 100644
> --- a/Documentation/DocBook/drm.tmpl
> +++ b/Documentation/DocBook/drm.tmpl
> @@ -1791,6 +1791,12 @@ void intel_crt_init(struct drm_device *dev)
> <title>KMS API Functions</title>
> !Edrivers/gpu/drm/drm_crtc.c
> </sect2>
> + <sect2>
> + <title>KMS Locking</title>
> +!Pdrivers/gpu/drm/drm_modeset_lock.c kms locking
> +!Iinclude/drm/drm_modeset_lock.h
> +!Edrivers/gpu/drm/drm_modeset_lock.c
> + </sect2>
> </sect1>
>
> <!-- Internals: kms helper functions -->
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index 863db84..dd2ba42 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 f3b98d4..43735f3 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -37,6 +37,7 @@
> #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"
>
> @@ -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;
> +
> + config->acquire_ctx = NULL;
> + drm_modeset_drop_locks(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);
> @@ -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 b55d27c..eb1c062 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 1ddc174..43329ce 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 0000000..19b4e91
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_modeset_lock.c
> @@ -0,0 +1,247 @@
> +/*
> + * Copyright (C) 2014 Red Hat
> + * Author: Rob Clark <robdclark at 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>
> +
> +/**
> + * 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 deadlock. But because
s/deadlock/deadlocks/.
> + * 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
Missing full stop after "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),
s/If deadlock/If a deadlock/
> + * you must call this function to drop all currently held locks and
> + * block until the contended lock to becomes available.
s/to//
> + */
> +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 it's acquire context is used and the lock
s/it's/its/
and maybe s/acquire context/ww acquire context/ since otherwise it's
unclear whether it's the drm lock context or the ww one we're talking
about here.
> + * 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 f3e0a23..1b15643 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 1fc91df5..5a045d3 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 c2976ad..1ce4ad4 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 c4d8839..58096fa 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_i2c_bus(&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 f1d5897..0de0498 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 b812e9d..2e2c71f 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 e97ea33..0396d13 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 d4d4156..2e1338a 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 d6acd6b..1b66ddc 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 25850a8..67c6c9a 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 76ccaab..475ca5c 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 6c295df..a7fac56 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..fbd9f23
> --- /dev/null
> +++ b/include/drm/drm_modeset_lock.h
> @@ -0,0 +1,123 @@
> +/*
> + * Copyright (C) 2014 Red Hat
> + * Author: Rob Clark <robdclark at 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;
> +
> +/**
> + * 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
Won't kerneldoc complain about the lack of @lock: here? More below of the
same.
> + */
> +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
> + */
> +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()
> + */
> +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_ */
> --
> 1.9.3
>
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
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