Some differences compared to Rob's patches again: - Dropped the committed and checked booleans. Checking will be internally enforced by always calling ->atomic_check before ->atomic_commit. And async handling needs to be solved differently because the current scheme completely side-steps ww mutex deadlock avoidance (and so either reinvents a new deadlock avoidance wheel or like the current code just deadlocks).
- State for connectors needed to be added, since now they have a full-blown drm_connector_state (so that drivers have something to attach their own stuff to).
- Refcounting is gone. I plane to solve async updates differently, since the lock-passing scheme doesn't cut it (since it abuses ww mutexes). Essentially what we need for async is a simple ownership transfer from the caller to the driver. That doesn't need full-blown refcounting.
- The acquire ctx is a pointer. Real atomic callers should have that on their stack, legacy entry points need to put the right one (obtained by drm_modeset_legacy_acuire_ctx) in there.
- I've dropped all hooks except check/commit. All the begin/end handling is done by core functions and is the same.
- commit/check are just thin wrappers that ensure that ->check is always called.
- To help out with locking in the legacy implementations I've added a helper to just grab all locks in the backoff case.
v2: Add notices that check/commit can fail with EDEADLK.
v3: - More consistent naming for state_alloc. - Add state_clear which is needed for backoff and retry.
v4: Planes/connectors can switch between crtcs, and we need to be careful that we grab the state (and locks) for both the old and new crtc. Improve the interface functions to ensure this.
v5: Add functions to grab affected connectors for a crtc and to recompute the crtc->enable state. This is useful for both helper and atomic ioctl code when e.g. removing a connector.
Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch --- drivers/gpu/drm/Makefile | 2 +- drivers/gpu/drm/drm_atomic.c | 529 +++++++++++++++++++++++++++++++++++++++++++ include/drm/drm_atomic.h | 63 ++++++ include/drm/drm_crtc.h | 23 ++ 4 files changed, 616 insertions(+), 1 deletion(-) create mode 100644 drivers/gpu/drm/drm_atomic.c create mode 100644 include/drm/drm_atomic.h
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index 61d9e9c6bc10..82e922c02c6d 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_modeset_lock.o + drm_modeset_lock.o drm_atomic.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_atomic.c b/drivers/gpu/drm/drm_atomic.c new file mode 100644 index 000000000000..29e77fe24e06 --- /dev/null +++ b/drivers/gpu/drm/drm_atomic.c @@ -0,0 +1,529 @@ +/* + * Copyright (C) 2014 Red Hat + * Copyright (C) 2014 Intel Corp. + * + * 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. + * + * Authors: + * Rob Clark robdclark@gmail.com + * Daniel Vetter daniel.vetter@ffwll.ch + */ + + +#include <drm/drmP.h> +#include <drm/drm_atomic.h> +#include <drm/drm_plane_helper.h> + +static void kfree_state(struct drm_atomic_state *state) +{ + kfree(state->connectors); + kfree(state->connector_states); + kfree(state->crtcs); + kfree(state->crtc_states); + kfree(state->planes); + kfree(state->plane_states); + kfree(state); +} + +/** + * drm_atomic_state_alloc - allocate atomic state + * @dev DRM device + * + * This allocates an empty atomic state to track updates. + */ +struct drm_atomic_state * +drm_atomic_state_alloc(struct drm_device *dev) +{ + struct drm_atomic_state *state; + + state = kzalloc(sizeof(*state), GFP_KERNEL); + if (!state) + return NULL; + + state->crtcs = kcalloc(sizeof(*state->crtcs), + dev->mode_config.num_crtc, GFP_KERNEL); + if (!state->crtcs) + goto fail; + state->crtc_states = kcalloc(sizeof(*state->crtc_states), + dev->mode_config.num_crtc, GFP_KERNEL); + if (!state->crtc_states) + goto fail; + state->planes = kcalloc(sizeof(*state->planes), + dev->mode_config.num_total_plane, GFP_KERNEL); + if (!state->planes) + goto fail; + state->plane_states = kcalloc(sizeof(*state->plane_states), + dev->mode_config.num_total_plane, + GFP_KERNEL); + if (!state->plane_states) + goto fail; + state->connectors = kcalloc(sizeof(*state->connectors), + dev->mode_config.num_connector, + GFP_KERNEL); + if (!state->connectors) + goto fail; + state->connector_states = kcalloc(sizeof(*state->connector_states), + dev->mode_config.num_connector, + GFP_KERNEL); + if (!state->connector_states) + goto fail; + + state->dev = dev; + + return state; +fail: + kfree_state(state); + + return NULL; +} +EXPORT_SYMBOL(drm_atomic_state_alloc); + +/** + * drm_atomic_state_clear - clear state object + * @state: atomic state + * + * When the w/w mutex algorithm detects a deadlock we need to back off and drop + * all locks. So someone else could sneak in and change the current modeset + * configuration. Which means that all the state assembled in @state is no + * longer an atomic update to the current state, but to some arbitrary earlier + * state. Which would break assumptions the driver's ->atomic_check likely + * relies on. + * + * Hence we must clear all cached state and complete start over, using this + * function. + */ +void drm_atomic_state_clear(struct drm_atomic_state *state) +{ + struct drm_device *dev = state->dev; + int i; + + for (i = 0; i < dev->mode_config.num_connector; i++) { + struct drm_connector *connector = state->connectors[i]; + + if (!connector) + continue; + + connector->funcs->atomic_destroy_state(connector, + state->connector_states[i]); + } + + for (i = 0; i < dev->mode_config.num_crtc; i++) { + struct drm_crtc *crtc = state->crtcs[i]; + + if (!crtc) + continue; + + crtc->funcs->atomic_destroy_state(crtc, + state->crtc_states[i]); + } + + for (i = 0; i < dev->mode_config.num_total_plane; i++) { + struct drm_plane *plane = state->planes[i]; + + if (!plane) + continue; + + plane->funcs->atomic_destroy_state(plane, + state->plane_states[i]); + } +} +EXPORT_SYMBOL(drm_atomic_state_clear); + +/** + * drm_atomic_state_free - free all memory for an atomic state + * @state: atomic state to deallocate + * + * This frees all memory associated with an atomic state, including all the + * per-object state for planes, crtcs and connectors. + */ +void drm_atomic_state_free(struct drm_atomic_state *state) +{ + drm_atomic_state_clear(state); + + kfree_state(state); +} +EXPORT_SYMBOL(drm_atomic_state_free); + +/** + * drm_atomic_get_crtc_state - get crtc state + * @state: global atomic state object + * @crtc: crtc to get state object for + * + * This functions returns the crtc state for the given crtc, allocating it if + * need. It will also grab the relevant crtc lock to make sure that the state is + * consistent. + * + * Returns: + * + * Either the allocated state or the error code encoded into the pointer. When + * the error is EDEADLK then the w/w mutex code has detected a deadlock and the + * entire atomic sequence must be restarted. All other errors are fatal. + */ +struct drm_crtc_state * +drm_atomic_get_crtc_state(struct drm_atomic_state *state, + struct drm_crtc *crtc) +{ + int ret, index; + struct drm_crtc_state *crtc_state; + + index = drm_crtc_index(crtc); + + if (state->crtc_states[index]) + return state->crtc_states[index]; + + ret = drm_modeset_lock(&crtc->mutex, state->acquire_ctx); + if (ret) + return ERR_PTR(ret); + + crtc_state = crtc->funcs->atomic_duplicate_state(crtc); + if (!crtc_state) + return ERR_PTR(-ENOMEM); + + state->crtc_states[index] = crtc_state; + state->crtcs[index] = crtc; + + return crtc_state; +} +EXPORT_SYMBOL(drm_atomic_get_crtc_state); + +/** + * drm_atomic_get_plane_state - get plane state + * @state: global atomic state object + * @plane: plane to get state object for + * + * This functions returns the plane state for the given plane, allocating it if + * need. It will also grab the relevant plane lock to make sure that the state is + * consistent. + * + * Returns: + * + * Either the allocated state or the error code encoded into the pointer. When + * the error is EDEADLK then the w/w mutex code has detected a deadlock and the + * entire atomic sequence must be restarted. All other errors are fatal. + */ +struct drm_plane_state * +drm_atomic_get_plane_state(struct drm_atomic_state *state, + struct drm_plane *plane) +{ + int ret, index; + struct drm_plane_state *plane_state; + + index = drm_plane_index(plane); + + if (state->plane_states[index]) + return state->plane_states[index]; + + /* + * TODO: We currently don't have per-plane mutexes. So instead of trying + * crazy tricks with deferring plane->crtc and hoping for the best just + * grab all crtc locks. Once we have per-plane locks we must update this + * to only take the plane mutex. + */ + ret = drm_modeset_lock_all_crtcs(state->dev, state->acquire_ctx); + if (ret) + return ERR_PTR(ret); + + plane_state = plane->funcs->atomic_duplicate_state(plane); + if (!plane_state) + return ERR_PTR(-ENOMEM); + + state->plane_states[index] = plane_state; + state->planes[index] = plane; + + if (plane_state->crtc) { + struct drm_crtc_state *crtc_state; + + crtc_state = drm_atomic_get_crtc_state(state, + plane_state->crtc); + if (IS_ERR(crtc_state)) + return ERR_PTR(PTR_ERR(crtc_state)); + } + + return plane_state; +} +EXPORT_SYMBOL(drm_atomic_get_plane_state); + +/** + * drm_atomic_get_connector_state - get connector state + * @state: global atomic state object + * @connector: connector to get state object for + * + * This functions returns the connector state for the given connector, allocating it if + * need. It will also grab the relevant connector lock to make sure that the state is + * consistent. + * + * Returns: + * + * Either the allocated state or the error code encoded into the pointer. When + * the error is EDEADLK then the w/w mutex code has detected a deadlock and the + * entire atomic sequence must be restarted. All other errors are fatal. + */ +struct drm_connector_state * +drm_atomic_get_connector_state(struct drm_atomic_state *state, + struct drm_connector *connector) +{ + int ret, index; + struct drm_mode_config *config = &connector->dev->mode_config; + struct drm_connector_state *connector_state; + + index = drm_connector_index(connector); + + if (state->connector_states[index]) + return state->connector_states[index]; + + ret = drm_modeset_lock(&config->connection_mutex, state->acquire_ctx); + if (ret) + return ERR_PTR(ret); + + connector_state = connector->funcs->atomic_duplicate_state(connector); + if (!connector_state) + return ERR_PTR(-ENOMEM); + + state->connector_states[index] = connector_state; + state->connectors[index] = connector; + + if (connector_state->crtc) { + struct drm_crtc_state *crtc_state; + + crtc_state = drm_atomic_get_crtc_state(state, + connector_state->crtc); + if (IS_ERR(crtc_state)) + return ERR_PTR(PTR_ERR(crtc_state)); + } + + return connector_state; +} +EXPORT_SYMBOL(drm_atomic_get_connector_state); + +/** + * drm_atomic_set_crtc_for_plane - set crtc for plane + * @plane_state: atomic state object for the plane + * @crtc: crtc to use for the plane + * + * Returns: + * 0 on success or can fail with -EDEADLK or -ENOMEM. + */ +int +drm_atomic_set_crtc_for_plane(struct drm_plane_state *plane_state, + struct drm_crtc *crtc) +{ + struct drm_crtc_state *crtc_state; + + crtc_state = drm_atomic_get_crtc_state(plane_state->state, crtc); + if (IS_ERR(crtc_state)) + return PTR_ERR(crtc_state); + + plane_state->crtc = crtc; + + return 0; +} +EXPORT_SYMBOL(drm_atomic_set_crtc_for_plane); + +/** + * drm_atomic_set_crtc_for_connector - set crtc for connector + * @connector_state: atomic state object for the connector + * @crtc: crtc to use for the connector + * + * Returns: + * 0 on success or can fail with -EDEADLK or -ENOMEM. + */ +int +drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state, + struct drm_crtc *crtc) +{ + struct drm_crtc_state *crtc_state; + + crtc_state = drm_atomic_get_crtc_state(conn_state->state, crtc); + if (IS_ERR(crtc_state)) + return PTR_ERR(crtc_state); + + conn_state->crtc = crtc; + + return 0; +} +EXPORT_SYMBOL(drm_atomic_set_crtc_for_connector); + +/** + * drm_atomic_add_affected_connectors - add connectors for crtc + * @state: atomic state + * @crtc: DRM crtc + * + * This functions walks the current configuration and adds all connectors + * currently using @crtc to the atomic configuration @state. + * + * Returns: + * 0 on success or can fail with -EDEADLK or -ENOMEM. + */ +int +drm_atomic_add_affected_connectors(struct drm_atomic_state *state, + struct drm_crtc *crtc) +{ + struct drm_mode_config *config = &state->dev->mode_config; + struct drm_connector *connector; + struct drm_connector_state *conn_state; + int ret; + + ret = drm_modeset_lock(&config->connection_mutex, state->acquire_ctx); + if (ret) + return ret; + + /* + * Changed connectors are already in @state, so only need to look at the + * current configuration. + */ + list_for_each_entry(connector, &config->connector_list, head) { + if (connector->state->crtc != crtc) + continue; + + conn_state = drm_atomic_get_connector_state(state, connector); + if (IS_ERR(conn_state)) + return PTR_ERR(conn_state); + } + + return 0; +} +EXPORT_SYMBOL(drm_atomic_add_affected_connectors); + +/** + * drm_atomic_connectors_for_crtc - count number of connected outputs + * @state: atomic state + * @crtc: DRM crtc + * + * This function counts all connectors which will be connected to @crtc + * according to @state. Useful to recompute the enable state for @crtc. + */ +int +drm_atomic_connectors_for_crtc(struct drm_atomic_state *state, + struct drm_crtc *crtc) +{ + int nconnectors = state->dev->mode_config.num_connector; + int i, num_connected_connectors = 0; + + for (i = 0; i < nconnectors; i++) { + struct drm_connector_state *conn_state; + + conn_state = state->connector_states[i]; + + if (conn_state && conn_state->crtc == crtc) + num_connected_connectors++; + } + + return num_connected_connectors; +} +EXPORT_SYMBOL(drm_atomic_connectors_for_crtc); + +/** + * drm_atomic_legacy_backoff - locking backoff for legacy ioctls + * @state: atomic state + * + * This function should be used by legacy entry points which don't understand + * -EDEADLK semantics. For simplicity this one will grab all modeset locks after + * the slowpath completed. + */ +void drm_atomic_legacy_backoff(struct drm_atomic_state *state) +{ + int ret; + +retry: + drm_modeset_backoff(state->acquire_ctx); + + ret = drm_modeset_lock(&state->dev->mode_config.connection_mutex, + state->acquire_ctx); + if (ret) + goto retry; + ret = drm_modeset_lock_all_crtcs(state->dev, + state->acquire_ctx); + if (ret) + goto retry; +} +EXPORT_SYMBOL(drm_atomic_legacy_backoff); + +/** + * drm_atomic_check_only - check whether a given config would work + * @state: atomic configuration to check + * + * Note that this function can return -EDEADLK if the driver needed to acquire + * more locks but encountered a deadlock. The caller must then do the usual w/w + * backoff dance and restart. + * + * Returns: + * 0 on success, negative error code on failure. + */ +int drm_atomic_check_only(struct drm_atomic_state *state) +{ + struct drm_mode_config *config = &state->dev->mode_config; + + if (config->funcs->atomic_check) + return config->funcs->atomic_check(state->dev, state); + else + return 0; +} +EXPORT_SYMBOL(drm_atomic_check_only); + +/** + * drm_atomic_commit - commit configuration atomically + * @state: atomic configuration to check + * + * Note that this function can return -EDEADLK if the driver needed to acquire + * more locks but encountered a deadlock. The caller must then do the usual w/w + * backoff dance and restart. + * + * Returns: + * 0 on etuccess, negative error code on failure. + */ +int drm_atomic_commit(struct drm_atomic_state *state) +{ + struct drm_mode_config *config = &state->dev->mode_config; + int ret; + + ret = drm_atomic_check_only(state); + if (ret) + return ret; + + return config->funcs->atomic_commit(state->dev, state, false); +} +EXPORT_SYMBOL(drm_atomic_commit); + +/** + * drm_atomic_async_commit - atomic&async onfiguration commit + * @state: atomic configuration to check + * + * Note that this function can return -EDEADLK if the driver needed to acquire + * more locks but encountered a deadlock. The caller must then do the usual w/w + * backoff dance and restart. + * + * Also note that ownership of @state is transferred from the caller of this function + * to the function itself. The caller must not free or in any other way access + * @state. + * + * Returns: + * 0 on success, negative error code on failure. + */ +int drm_atomic_async_commit(struct drm_atomic_state *state) +{ + struct drm_mode_config *config = &state->dev->mode_config; + int ret; + + ret = drm_atomic_check_only(state); + if (ret) + return ret; + + return config->funcs->atomic_commit(state->dev, state, true); +} +EXPORT_SYMBOL(drm_atomic_async_commit); diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h new file mode 100644 index 000000000000..753812034e71 --- /dev/null +++ b/include/drm/drm_atomic.h @@ -0,0 +1,63 @@ +/* + * Copyright (C) 2014 Red Hat + * Copyright (C) 2014 Intel Corp. + * + * 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. + * + * Authors: + * Rob Clark robdclark@gmail.com + * Daniel Vetter daniel.vetter@ffwll.ch + */ + +#ifndef DRM_ATOMIC_H_ +#define DRM_ATOMIC_H_ + +struct drm_atomic_state * +drm_atomic_state_alloc(struct drm_device *dev); +void drm_atomic_state_clear(struct drm_atomic_state *state); +void drm_atomic_state_free(struct drm_atomic_state *state); + +struct drm_crtc_state * +drm_atomic_get_crtc_state(struct drm_atomic_state *state, + struct drm_crtc *crtc); +struct drm_plane_state * +drm_atomic_get_plane_state(struct drm_atomic_state *state, + struct drm_plane *plane); +struct drm_connector_state * +drm_atomic_get_connector_state(struct drm_atomic_state *state, + struct drm_connector *connector); + +int drm_atomic_set_crtc_for_plane(struct drm_plane_state *plane_state, + struct drm_crtc *crtc); +int drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state, + struct drm_crtc *crtc); +int +drm_atomic_add_affected_connectors(struct drm_atomic_state *state, + struct drm_crtc *crtc); +int +drm_atomic_connectors_for_crtc(struct drm_atomic_state *state, + struct drm_crtc *crtc); + +void drm_atomic_legacy_backoff(struct drm_atomic_state *state); + +int drm_atomic_check_only(struct drm_atomic_state *state); +int drm_atomic_commit(struct drm_atomic_state *state); +int drm_atomic_async_commit(struct drm_atomic_state *state); + +#endif /* DRM_ATOMIC_H_ */ diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index 39465d716db6..d79f2e0e8104 100644 --- a/include/drm/drm_crtc.h +++ b/include/drm/drm_crtc.h @@ -822,6 +822,23 @@ struct drm_bridge { };
/** + * struct drm_atomic_state - the global state object for atomic updates + */ +struct drm_atomic_state { + struct drm_device *dev; + uint32_t flags; + struct drm_plane **planes; + struct drm_plane_state **plane_states; + struct drm_crtc **crtcs; + struct drm_crtc_state **crtc_states; + struct drm_connector **connectors; + struct drm_connector_state **connector_states; + + struct drm_modeset_acquire_ctx *acquire_ctx; +}; + + +/** * drm_mode_set - new values for a CRTC config change * @head: list management * @fb: framebuffer to use for new config @@ -862,6 +879,12 @@ struct drm_mode_config_funcs { struct drm_file *file_priv, struct drm_mode_fb_cmd2 *mode_cmd); void (*output_poll_changed)(struct drm_device *dev); + + int (*atomic_check)(struct drm_device *dev, + struct drm_atomic_state *a); + int (*atomic_commit)(struct drm_device *dev, + struct drm_atomic_state *a, + bool async); };
/**