diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl
index 00f1c25e53df8f41a5e220a5ccece2711e6f9563..efef63717ef619d2d53a4d6cebf3ef1b2eabf44c 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 863db8415c22ff1d1bcf56cc02740c69f4d7e9a5..dd2ba4269740f563ac29eecadbe62b40bf55ade3 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 f3b98d4b6f4604247274fffc95da6f5b6f8b926e..43735f38cd17fd4c7eb6dc7851d8508f4c668bba 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 @@ int drm_mode_page_flip_ioctl(struct drm_device *dev,
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 b55d27c872f6cf6d6ea40a6fb8fced50796d6501..eb1c062e04b248b16468b46498a420fbfd327294 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 1ddc17464250c23cfec7b2ac50bcac495053124f..43329cee299f6d6173a95114923a7aa55f56d1fa 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 0000000000000000000000000000000000000000..7c2497dea1e9924d5a63f854af6ecbae19087dc2
--- /dev/null
+++ b/drivers/gpu/drm/drm_modeset_lock.c
@@ -0,0 +1,247 @@
+/*
+ * 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>
+
+/**
+ * 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 f3e0a23abf4e064188e436803d9e6fd1bb3a36da..1b15643b45869414e53ba853d476e4bc97c0ef69 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 1fc91df5829662a69f745f1d73601c66ca2bf4ad..5a045d3bd77e7c7f77c7e8fc55292d37714eab3a 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 c2976ade823fa1b8e0d3d381e09342c02f90843a..1ce4ad4626e4f1114bf7e6b957d9b0c781db4e77 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 d01bb430b5bcacf61a21a5e5748ac02f410e2a12..2d5d9b0100731d1e10056aa4287c7261b5182307 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 f1d5897c96cd0b2003195462a78e62fd936a624e..0de04983501e12969fcc127293a053a8c10452f4 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 b812e9d39f3853c6efeb4c1db0f1bcf6b4a0539e..2e2c71fcc9ed502dc3a013089d53a3270999ad51 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 e97ea33e01179d4ce521e10dab99bbdbbfd02464..0396d1312b5c1d57100e4801fe004cc13ef19dad 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 d4d415665475eb74e23d3368d967fe1920387e3b..2e1338a5d488ac6fdce729dc29bcd764dd2f6861 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 d6acd6bd0bf02bc09166f27065de21f333101e0a..1b66ddcdfb331cdcb83dd9558ce494041cebc2b3 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 25850a86d70c043d614df05d7323fadb93fc675f..67c6c9a2eb1c9f3ed3d0d6979a686b52fdabe9fe 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 e3c47a8005ff149e07b5770f38cdaf1b9aba394f..2d28dc337cfb4ed50104370478021738de688316 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 e7199b454ca055ce4afd87a3ce1e379b98159eda..8f3edc4710f2869344fec29c6366caa2a1d77dc2 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 76ccaabd041853518655c5ce093591ce5f4d106b..475ca5cf3c20007be416b5744353fe4eced8d2fa 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 6c295df7b0dffdb976baabca26f38fe1756a35a0..a7fac5686915f21c728315a9c6533cb25cf9879a 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 0000000000000000000000000000000000000000..402aa7a6a058dc68e3923d1ee2ad7296800d3d69
--- /dev/null
+++ b/include/drm/drm_modeset_lock.h
@@ -0,0 +1,126 @@
+/*
+ * 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;
+
+/**
+ * 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_ */