From cc4ceb484b37b9369e0d4e8682b7ae1849ae4579 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Fri, 25 Jul 2014 21:30:38 +0200 Subject: drm: Global atomic state handling 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. v6: Squash in fixup from Fengguang to use ERR_CAST. v7: Add debug output. v8: Make checkpatch happy about kcalloc argument ordering. v9: Improve kerneldoc in drm_crtc.h v10: - Fix another kcalloc argument misorder I've missed. - More polish for kerneldoc. v11: Clarify the ownership rules for the state object. The new rule is that a successful drm_atomic_commit (whether synchronous or asnyc) always inherits the state and is responsible for the clean-up. That way async and sync ->commit functions are more similar. v12: A few bugfixes: - Assign state->state pointers correctly when grabbing state objects - we need to link them up with the global state. - Handle a NULL crtc in set_crtc_for_plane to simplify code flow a bit for the callers of this function. v13: Review from Sean: - kerneldoc spelling fixes - Don't overallocate states->planes. - Handle NULL crtc in set_crtc_for_connector. v14: Sprinkle __must_check over all functions which do wait/wound locking to make sure callers don't forget this. Since I have ;-) v15: Be more explicit in the kerneldoc when functions can return -EDEADLK what to do. And that every other -errno is fatal. v16: Indent with tabs instead of space, spotted by Ander. v17: Review from Thierry, small kerneldoc and other naming polish. Cc: Thierry Reding Cc: Ander Conselvan de Oliveira Cc: Daniel Thompson Cc: Fengguang Wu Cc: Sean Paul Cc: Matt Roper Reviewed-by: Sean Paul Signed-off-by: Daniel Vetter --- drivers/gpu/drm/drm_atomic.c | 600 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 600 insertions(+) create mode 100644 drivers/gpu/drm/drm_atomic.c (limited to 'drivers/gpu/drm/drm_atomic.c') diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c new file mode 100644 index 000000000000..ad15a88c0f74 --- /dev/null +++ b/drivers/gpu/drm/drm_atomic.c @@ -0,0 +1,600 @@ +/* + * 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 + * Daniel Vetter + */ + + +#include +#include +#include + +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(dev->mode_config.num_crtc, + sizeof(*state->crtcs), GFP_KERNEL); + if (!state->crtcs) + goto fail; + state->crtc_states = kcalloc(dev->mode_config.num_crtc, + sizeof(*state->crtc_states), GFP_KERNEL); + if (!state->crtc_states) + goto fail; + state->planes = kcalloc(dev->mode_config.num_total_plane, + sizeof(*state->planes), GFP_KERNEL); + if (!state->planes) + goto fail; + state->plane_states = kcalloc(dev->mode_config.num_total_plane, + sizeof(*state->plane_states), GFP_KERNEL); + if (!state->plane_states) + goto fail; + state->connectors = kcalloc(dev->mode_config.num_connector, + sizeof(*state->connectors), + GFP_KERNEL); + if (!state->connectors) + goto fail; + state->connector_states = kcalloc(dev->mode_config.num_connector, + sizeof(*state->connector_states), + GFP_KERNEL); + if (!state->connector_states) + goto fail; + + state->dev = dev; + + DRM_DEBUG_KMS("Allocate atomic state %p\n", state); + + 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 could break assumptions the driver's ->atomic_check likely + * relies on. + * + * Hence we must clear all cached state and completely start over, using this + * function. + */ +void drm_atomic_state_clear(struct drm_atomic_state *state) +{ + struct drm_device *dev = state->dev; + int i; + + DRM_DEBUG_KMS("Clearing atomic state %p\n", state); + + 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); + + DRM_DEBUG_KMS("Freeing atomic state %p\n", 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 function returns the crtc state for the given crtc, allocating it if + * needed. 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; + crtc_state->state = state; + + DRM_DEBUG_KMS("Added [CRTC:%d] %p state to %p\n", + crtc->base.id, crtc_state, state); + + 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 function returns the plane state for the given plane, allocating it if + * needed. 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; + plane_state->state = state; + + DRM_DEBUG_KMS("Added [PLANE:%d] %p state to %p\n", + plane->base.id, plane_state, state); + + 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_CAST(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 function returns the connector state for the given connector, + * allocating it if needed. 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; + connector_state->state = state; + + DRM_DEBUG_KMS("Added [CONNECTOR:%d] %p state to %p\n", + connector->base.id, connector_state, state); + + 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_CAST(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 + * + * Changing the assigned crtc for a plane requires us to grab the lock and state + * for the new crtc, as needed. This function takes care of all these details + * besides updating the pointer in the state object itself. + * + * Returns: + * 0 on success or can fail with -EDEADLK or -ENOMEM. 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. + */ +int +drm_atomic_set_crtc_for_plane(struct drm_plane_state *plane_state, + struct drm_crtc *crtc) +{ + struct drm_crtc_state *crtc_state; + + if (crtc) { + 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; + + if (crtc) + DRM_DEBUG_KMS("Link plane state %p to [CRTC:%d]\n", + plane_state, crtc->base.id); + else + DRM_DEBUG_KMS("Link plane state %p to [NOCRTC]\n", plane_state); + + return 0; +} +EXPORT_SYMBOL(drm_atomic_set_crtc_for_plane); + +/** + * drm_atomic_set_crtc_for_connector - set crtc for connector + * @conn_state: atomic state object for the connector + * @crtc: crtc to use for the connector + * + * Changing the assigned crtc for a connector requires us to grab the lock and + * state for the new crtc, as needed. This function takes care of all these + * details besides updating the pointer in the state object itself. + * + * Returns: + * 0 on success or can fail with -EDEADLK or -ENOMEM. 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. + */ +int +drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state, + struct drm_crtc *crtc) +{ + struct drm_crtc_state *crtc_state; + + if (crtc) { + 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; + + if (crtc) + DRM_DEBUG_KMS("Link connector state %p to [CRTC:%d]\n", + conn_state, crtc->base.id); + else + DRM_DEBUG_KMS("Link connector state %p to [NOCRTC]\n", + conn_state); + + 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 function walks the current configuration and adds all connectors + * currently using @crtc to the atomic configuration @state. Note that this + * function must acquire the connection mutex. This can potentially cause + * unneeded seralization if the update is just for the planes on one crtc. Hence + * drivers and helpers should only call this when really needed (e.g. when a + * full modeset needs to happen due to some change). + * + * Returns: + * 0 on success or can fail with -EDEADLK or -ENOMEM. 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. + */ +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; + + DRM_DEBUG_KMS("Adding all current connectors for [CRTC:%d] to %p\n", + crtc->base.id, state); + + /* + * 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++; + } + + DRM_DEBUG_KMS("State %p has %i connectors for [CRTC:%d]\n", + state, num_connected_connectors, crtc->base.id); + + 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. All other errors are fatal. + * + * 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; + + DRM_DEBUG_KMS("checking %p\n", state); + + 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. All other errors are fatal. + * + * Also note that on successful execution 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. If the function fails then the caller + * must clean up @state itself. + * + * Returns: + * 0 on success, 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; + + DRM_DEBUG_KMS("commiting %p\n", state); + + return config->funcs->atomic_commit(state->dev, state, false); +} +EXPORT_SYMBOL(drm_atomic_commit); + +/** + * drm_atomic_async_commit - atomic&async configuration 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. All other errors are fatal. + * + * Also note that on successful execution 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. If the function fails then the caller + * must clean up @state itself. + * + * 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; + + DRM_DEBUG_KMS("commiting %p asynchronously\n", state); + + return config->funcs->atomic_commit(state->dev, state, true); +} +EXPORT_SYMBOL(drm_atomic_async_commit); -- cgit v1.2.3 From 321ebf04dc7ab5c54d658f93db0ffe35277664ab Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Tue, 4 Nov 2014 22:57:27 +0100 Subject: drm/atomic: Refcounting for plane_state->fb So my original plan was that the drm core refcounts framebuffers like with the legacy ioctls. But that doesn't work for a bunch of reasons: - State objects might live longer than until the next fb change happens for a plane. For example delayed cleanup work only happens _after_ the pageflip ioctl has completed. So this definitely doesn't work without the plane state holding its own references. - The other issue is transition from legacy to atomic implementations, where the driver works under a mix of both worlds. Which means legacy paths might not properly update the ->fb pointer under plane->state->fb. Which is a bit a problem when then someone comes around and _does_ try to clean it up when it's long gone. The second issue is just a bit a transition bug, since drivers should update plane->state->fb in all the paths that aren't converted yet. But a bit more robustness for the transition can't hurt - we pull similar tricks with cleaning up the old fb in the transitional helpers already. The pattern for drivers that transition is if (plane->state) drm_atomic_set_fb_for_plane(plane->state, plane->fb); inserted after the fb update has logically completed at the end of ->set_config (or ->set_base/mode_set if using the crtc helpers), ->page_flip, ->update_plane or any other entry point which updates plane->fb. v2: Update kerneldoc - copypasta fail. v3: Fix spelling in the commit message (Sean). Reviewed-by: Sean Paul Signed-off-by: Daniel Vetter --- drivers/gpu/drm/drm_atomic.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'drivers/gpu/drm/drm_atomic.c') diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c index ad15a88c0f74..ed991ba66e21 100644 --- a/drivers/gpu/drm/drm_atomic.c +++ b/drivers/gpu/drm/drm_atomic.c @@ -367,6 +367,34 @@ drm_atomic_set_crtc_for_plane(struct drm_plane_state *plane_state, } EXPORT_SYMBOL(drm_atomic_set_crtc_for_plane); +/** + * drm_atomic_set_fb_for_plane - set crtc for plane + * @plane_state: atomic state object for the plane + * @fb: fb to use for the plane + * + * Changing the assigned framebuffer for a plane requires us to grab a reference + * to the new fb and drop the reference to the old fb, if there is one. This + * function takes care of all these details besides updating the pointer in the + * state object itself. + */ +void +drm_atomic_set_fb_for_plane(struct drm_plane_state *plane_state, + struct drm_framebuffer *fb) +{ + if (plane_state->fb) + drm_framebuffer_unreference(plane_state->fb); + if (fb) + drm_framebuffer_reference(fb); + plane_state->fb = fb; + + if (fb) + DRM_DEBUG_KMS("Set [FB:%d] for plane state %p\n", + fb->base.id, plane_state); + else + DRM_DEBUG_KMS("Set [NOFB] for plane state %p\n", plane_state); +} +EXPORT_SYMBOL(drm_atomic_set_fb_for_plane); + /** * drm_atomic_set_crtc_for_connector - set crtc for connector * @conn_state: atomic state object for the connector -- cgit v1.2.3 From 4d02e2de0e80a786452e70d7f3a20a50641e6620 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Tue, 11 Nov 2014 10:12:00 +0100 Subject: drm: Per-plane locking Turned out to be much simpler on top of my latest atomic stuff than what I've feared. Some details: - Drop the modeset_lock_all snakeoil in drm_plane_init. Same justification as for the equivalent change in drm_crtc_init done in commit d0fa1af40e784aaf7ebb7ba8a17b229bb3fa4c21 Author: Daniel Vetter Date: Mon Sep 8 09:02:49 2014 +0200 drm: Drop modeset locking from crtc init function Without these the drm_modeset_lock_init would fall over the exact same way. - Since the atomic core code wraps the locking switching it to per-plane locks was a one-line change. - For the legacy ioctls add a plane argument to the locking helper so that we can grab the right plane lock (cursor or primary). Since the universal cursor plane might not be there, or someone really crazy might forgoe the primary plane even accept NULL. - Add some locking WARN_ON to the atomic helpers for good paranoid measure and to check that it all works out. Tested on my exynos atomic hackfest with full lockdep checks and ww backoff injection. v2: I've forgotten about the load-detect code in i915. v3: Thierry reported that in latest 3.18-rc vmwgfx doesn't compile any more due to commit 21e88620aa21b48d4f62d29275e3e2944a5ea2b5 Author: Rob Clark Date: Thu Oct 30 13:39:04 2014 -0400 drm/vmwgfx: fix lock breakage Rebased and fix this up. Cc: Thierry Reding Signed-off-by: Daniel Vetter Reviewed-by: Sean Paul Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_atomic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/gpu/drm/drm_atomic.c') diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c index ed991ba66e21..ed22a719440f 100644 --- a/drivers/gpu/drm/drm_atomic.c +++ b/drivers/gpu/drm/drm_atomic.c @@ -244,7 +244,7 @@ drm_atomic_get_plane_state(struct drm_atomic_state *state, * 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); + ret = drm_modeset_lock(&plane->mutex, state->acquire_ctx); if (ret) return ERR_PTR(ret); -- cgit v1.2.3 From c7eb76f4931b505e57c6510133df19f4ec1ce3e5 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Wed, 19 Nov 2014 18:38:06 +0100 Subject: drm/atomic: Ensure that drm_connector_index is stable I've totally forgotten that with DP MST connectors can now be hotplugged. And failed to adapt Rob's drm_atomic_state code (which predates connector hotplugging) to the new realities. The first step is to make sure that the connector indices used to access the arrays of pointers are stable. The connection mutex gives us enough guarantees for that, which means we won't unecessarily block on concurrent modesets or background probing. So add a locking WARN_ON and shuffle the code slightly to make sure we always hold the right lock. Signed-off-by: Daniel Vetter Reviewed-by: Rob Clark Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_atomic.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'drivers/gpu/drm/drm_atomic.c') diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c index ed22a719440f..90b2d1644bd7 100644 --- a/drivers/gpu/drm/drm_atomic.c +++ b/drivers/gpu/drm/drm_atomic.c @@ -295,15 +295,15 @@ drm_atomic_get_connector_state(struct drm_atomic_state *state, struct drm_mode_config *config = &connector->dev->mode_config; struct drm_connector_state *connector_state; + ret = drm_modeset_lock(&config->connection_mutex, state->acquire_ctx); + if (ret) + return ERR_PTR(ret); + 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); -- cgit v1.2.3 From 6f75cea66c8dd043ced282016b21a639af176642 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Wed, 19 Nov 2014 18:38:07 +0100 Subject: drm/atomic: Only destroy connector states with connection mutex held Otherwise the connector might have been unplugged and destroyed while we didn't look. Yet another fallout from DP MST hotplugging that I didn't consider. To make sure we get this right add an appropriate WARN_ON to drm_atomic_state_clear (obviously only when we actually have a state to clear up). And reorder all the state_clear and backoff calls to make it work out properly. Signed-off-by: Daniel Vetter Reviewed-by: Rob Clark Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_atomic.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'drivers/gpu/drm/drm_atomic.c') diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c index 90b2d1644bd7..67c1dc894bd9 100644 --- a/drivers/gpu/drm/drm_atomic.c +++ b/drivers/gpu/drm/drm_atomic.c @@ -112,21 +112,24 @@ EXPORT_SYMBOL(drm_atomic_state_alloc); void drm_atomic_state_clear(struct drm_atomic_state *state) { struct drm_device *dev = state->dev; + struct drm_mode_config *config = &dev->mode_config; int i; DRM_DEBUG_KMS("Clearing atomic state %p\n", state); - for (i = 0; i < dev->mode_config.num_connector; i++) { + for (i = 0; i < config->num_connector; i++) { struct drm_connector *connector = state->connectors[i]; if (!connector) continue; + WARN_ON(!drm_modeset_is_locked(&config->connection_mutex)); + connector->funcs->atomic_destroy_state(connector, state->connector_states[i]); } - for (i = 0; i < dev->mode_config.num_crtc; i++) { + for (i = 0; i < config->num_crtc; i++) { struct drm_crtc *crtc = state->crtcs[i]; if (!crtc) @@ -136,7 +139,7 @@ void drm_atomic_state_clear(struct drm_atomic_state *state) state->crtc_states[i]); } - for (i = 0; i < dev->mode_config.num_total_plane; i++) { + for (i = 0; i < config->num_total_plane; i++) { struct drm_plane *plane = state->planes[i]; if (!plane) -- cgit v1.2.3 From f52b69f1ecfdd7ef6867a257620258c09e569552 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Wed, 19 Nov 2014 18:38:08 +0100 Subject: drm/atomic: Don't overrun the connector array when hotplugging Yet another fallout from not considering DP MST hotplug. With the previous patches we have stable indices, but it might still happen that a connector gets added between when we allocate the array and when we actually add a connector. Especially when we back off due to ww mutex contention or similar issues. So store the sizes of the arrays in struct drm_atomic_state and double check them. We don't really care about races except that we want to use a consistent value, so ACCESS_ONCE is all we need. And if we indeed notice that we'd overrun the array then just give up and restart the entire ioctl. Signed-off-by: Daniel Vetter Reviewed-by: Rob Clark Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_atomic.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) (limited to 'drivers/gpu/drm/drm_atomic.c') diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c index 67c1dc894bd9..3624632084e2 100644 --- a/drivers/gpu/drm/drm_atomic.c +++ b/drivers/gpu/drm/drm_atomic.c @@ -56,6 +56,8 @@ drm_atomic_state_alloc(struct drm_device *dev) if (!state) return NULL; + state->num_connector = ACCESS_ONCE(dev->mode_config.num_connector); + state->crtcs = kcalloc(dev->mode_config.num_crtc, sizeof(*state->crtcs), GFP_KERNEL); if (!state->crtcs) @@ -72,12 +74,12 @@ drm_atomic_state_alloc(struct drm_device *dev) sizeof(*state->plane_states), GFP_KERNEL); if (!state->plane_states) goto fail; - state->connectors = kcalloc(dev->mode_config.num_connector, + state->connectors = kcalloc(state->num_connector, sizeof(*state->connectors), GFP_KERNEL); if (!state->connectors) goto fail; - state->connector_states = kcalloc(dev->mode_config.num_connector, + state->connector_states = kcalloc(state->num_connector, sizeof(*state->connector_states), GFP_KERNEL); if (!state->connector_states) @@ -117,7 +119,7 @@ void drm_atomic_state_clear(struct drm_atomic_state *state) DRM_DEBUG_KMS("Clearing atomic state %p\n", state); - for (i = 0; i < config->num_connector; i++) { + for (i = 0; i < state->num_connector; i++) { struct drm_connector *connector = state->connectors[i]; if (!connector) @@ -304,6 +306,21 @@ drm_atomic_get_connector_state(struct drm_atomic_state *state, index = drm_connector_index(connector); + /* + * Construction of atomic state updates can race with a connector + * hot-add which might overflow. In this case flip the table and just + * restart the entire ioctl - no one is fast enough to livelock a cpu + * with physical hotplug events anyway. + * + * Note that we only grab the indexes once we have the right lock to + * prevent hotplug/unplugging of connectors. So removal is no problem, + * at most the array is a bit too large. + */ + if (index >= state->num_connector) { + DRM_DEBUG_KMS("Hot-added connector would overflow state array, restarting\n"); + return -EAGAIN; + } + if (state->connector_states[index]) return state->connector_states[index]; @@ -499,10 +516,9 @@ 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++) { + for (i = 0; i < state->num_connector; i++) { struct drm_connector_state *conn_state; conn_state = state->connector_states[i]; -- cgit v1.2.3 From fc2d2bc1f1f8d8351f884bb65b5cc4ad2411b2a7 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Thu, 20 Nov 2014 09:53:35 +0100 Subject: drm/atomic: Add missing ERR_PTR casting This is an oversight from commit f52b69f1ecfdd7ef6867a257620258c09e569552 Author: Daniel Vetter Date: Wed Nov 19 18:38:08 2014 +0100 drm/atomic: Don't overrun the connector array when hotplugging Cc: Dave Airlie Cc: Rob Clark Signed-off-by: Daniel Vetter Reviewed-by: Thierry Reding Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_atomic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/gpu/drm/drm_atomic.c') diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c index 3624632084e2..d3b46746b611 100644 --- a/drivers/gpu/drm/drm_atomic.c +++ b/drivers/gpu/drm/drm_atomic.c @@ -318,7 +318,7 @@ drm_atomic_get_connector_state(struct drm_atomic_state *state, */ if (index >= state->num_connector) { DRM_DEBUG_KMS("Hot-added connector would overflow state array, restarting\n"); - return -EAGAIN; + return ERR_PTR(-EAGAIN); } if (state->connector_states[index]) -- cgit v1.2.3 From 9c04b7e3698a2e77b3473ef91a26ecb384459a04 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Mon, 24 Nov 2014 20:51:21 +0100 Subject: drm/atomic: Drop per-plane locking TODO I've forgotten to remove that in my per-plane locking patch. Reported-by: Rob Clark Signed-off-by: Daniel Vetter --- drivers/gpu/drm/drm_atomic.c | 6 ------ 1 file changed, 6 deletions(-) (limited to 'drivers/gpu/drm/drm_atomic.c') diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c index d3b46746b611..ba49b5ca822f 100644 --- a/drivers/gpu/drm/drm_atomic.c +++ b/drivers/gpu/drm/drm_atomic.c @@ -243,12 +243,6 @@ drm_atomic_get_plane_state(struct drm_atomic_state *state, 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(&plane->mutex, state->acquire_ctx); if (ret) return ERR_PTR(ret); -- cgit v1.2.3 From 6ddd388ab222b66b596342becc76d5031c0e2fc8 Mon Sep 17 00:00:00 2001 From: Rob Clark Date: Fri, 21 Nov 2014 15:28:31 -0500 Subject: drm/atomic: track bitmask of planes attached to crtc Chasing plane->state->crtc of planes that are *not* part of the same atomic update is racy, making it incredibly awkward (or impossible) to do something simple like iterate over all planes and figure out which ones are attached to a crtc. Solve this by adding a bitmask of currently attached planes in the crtc-state. Note that the transitional helpers do not maintain the plane_mask. But they only support the legacy ioctls, which have sufficient brute-force locking around plane updates that they can continue to loop over all planes to see what is attached to a crtc the old way. Signed-off-by: Rob Clark [danvet: - Drop comments about locking in set_crtc_for_plane since they're a bit misleading - we already should hold lock for the current crtc. - Also WARN_ON if get_state on the old crtc fails since that should have been done already. - Squash in fixup to check get_plane_state return value, reported by Dan Carpenter and acked by Rob Clark.] Signed-off-by: Daniel Vetter --- drivers/gpu/drm/drm_atomic.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) (limited to 'drivers/gpu/drm/drm_atomic.c') diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c index ba49b5ca822f..ff5f034cc405 100644 --- a/drivers/gpu/drm/drm_atomic.c +++ b/drivers/gpu/drm/drm_atomic.c @@ -344,7 +344,8 @@ 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 + * @state: the incoming atomic state + * @plane: the plane whose incoming state to update * @crtc: crtc to use for the plane * * Changing the assigned crtc for a plane requires us to grab the lock and state @@ -357,20 +358,35 @@ EXPORT_SYMBOL(drm_atomic_get_connector_state); * sequence must be restarted. All other errors are fatal. */ int -drm_atomic_set_crtc_for_plane(struct drm_plane_state *plane_state, - struct drm_crtc *crtc) +drm_atomic_set_crtc_for_plane(struct drm_atomic_state *state, + struct drm_plane *plane, struct drm_crtc *crtc) { + struct drm_plane_state *plane_state = + drm_atomic_get_plane_state(state, plane); struct drm_crtc_state *crtc_state; + if (WARN_ON(IS_ERR(plane_state))) + return PTR_ERR(plane_state); + + if (plane_state->crtc) { + crtc_state = drm_atomic_get_crtc_state(plane_state->state, + plane_state->crtc); + if (WARN_ON(IS_ERR(crtc_state))) + return PTR_ERR(crtc_state); + + crtc_state->plane_mask &= ~(1 << drm_plane_index(plane)); + } + + plane_state->crtc = crtc; + if (crtc) { crtc_state = drm_atomic_get_crtc_state(plane_state->state, crtc); if (IS_ERR(crtc_state)) return PTR_ERR(crtc_state); + crtc_state->plane_mask |= (1 << drm_plane_index(plane)); } - plane_state->crtc = crtc; - if (crtc) DRM_DEBUG_KMS("Link plane state %p to [CRTC:%d]\n", plane_state, crtc->base.id); -- cgit v1.2.3