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OpenCloudOS-Kernel/include/drm/drm_atomic_helper.h

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drm: Add atomic/plane helpers This is the first cut of atomic helper code. As-is it's only useful to implement a pure atomic interface for plane updates. Later patches will integrate this with the crtc helpers so that full atomic updates are possible. We also need a pile of helpers to aid drivers in transitioning from the legacy world to the shiny new atomic age. Finally we need helpers to implement legacy ioctls on top of the atomic interface. The design of the overall helpers<->driver interaction is fairly simple, but has an unfortunate large interface: - We have ->atomic_check callbacks for crtcs and planes. The idea is that connectors don't need any checking, and if they do they can adjust the relevant crtc driver-private state. So no connector hooks should be needed. Also the crtc helpers integration will do the ->best_encoder checks, so no need for that. - Framebuffer pinning needs to be done before we can commit to the hw state. This is especially important for async updates where we must pin all buffers before returning to userspace, so that really only hw failures can happen in the asynchronous worker. Hence we add ->prepare_fb and ->cleanup_fb hooks for this resources management. - The actual atomic plane commit can't fail (except hw woes), so has void return type. It has three stages: 1. Prepare all affected crtcs with crtc->atomic_begin. Drivers can use this to unset the GO bit or similar latches to prevent plane updates. 2. Update plane state by looping over all changed planes and calling plane->atomic_update. Presuming the hardware is sane and has GO bits drivers can simply bash the state into the hardware in this function. Other drivers might use this to precompute hw state for the final step. 3. Finally latch the update for the next vblank with crtc->atomic_flush. Note that this function doesn't need to wait for the vblank to happen even for the synchronous case. v2: Clear drm_<obj>_state->state to NULL when swapping in state. v3: Add TODO that we don't short-circuit plane updates for now. Likely no one will care. v4: Squash in a bit of polish that somehow landed in the wrong (later) patche. v5: Integrate atomic functions into the drm docbook and fixup the kerneldoc. v6: Fixup fixup patch squashing fumble. v7: Don't touch the legacy plane state plane->fb and plane->crtc. This is only used by the legacy ioctl code in the drm core, and that code already takes care of updating the pointers in all relevant cases. This is in stark contrast to connector->encoder->crtc links on the modeset side, which we still need to set since the core doesn't touch them. Also some more kerneldoc polish. v8: Drop outdated comment. v9: Handle the state->state pointer correctly: Only clearing the ->state pointer when assigning the state to the kms object isn't good enough. We also need to re-link the swapped out state into the drm_atomic_state structure. v10: Shuffle the misplaced docbook template hunk around that Sean spotted. Cc: Sean Paul <seanpaul@chromium.org> Reviewed-by: Sean Paul <seanpaul@chromium.org> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2014-11-05 07:14:14 +08:00
/*
* 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_HELPER_H_
#define DRM_ATOMIC_HELPER_H_
int drm_atomic_helper_check(struct drm_device *dev,
struct drm_atomic_state *state);
drm: Atomic crtc/connector updates using crtc/plane helper interfaces So this is finally the integration of the crtc and plane helper interfaces into the atomic helper functions. In the check function we now have a few steps: - First we update the output routing and figure out which crtcs need a full mode set. Suitable encoders are selected using ->best_encoder, with the same semantics as the crtc helpers of implicitly disabling all connectors currently using the encoder. - Then we pull all other connectors into the state update which feed from a crtc which changes. This must be done do catch mode changes and similar updates - atomic updates are differences on top of the current state. - Then we call all the various ->mode_fixup to compute the adjusted mode. Note that here we have a slight semantic difference compared to the crtc helpers: We have not yet updated the encoder->crtc link when calling the encoder's ->mode_fixup function. But that's a requirement when converting to atomic since we want to prepare the entire state completely contained with the over drm_atomic_state structure. So this must be carefully checked when converting drivers over to atomic helpers. - Finally we do call the atomic_check functions on planes and crtcs. The commit function is also quite a beast: - The only step that can fail is done first, namely pinning the framebuffers. After that we cross the point of no return, an async commit would push all that into the worker thread. - The disabling of encoders and connectors is a bit tricky, since depending upon the final state we need to select different crtc helper functions. - Software tracking is a bit clarified compared to the crtc helpers: We commit the software state before starting to touch the hardware, like crtc helpers. But since we just swap them we still have the old state (i.e. the current hw state) around, which is really handy to write simple disable functions. So no more drm_crtc_helper_disable_all_unused_functions kind of fun because we're leaving unused crtcs/encoders behind. Everything gets shut down in-order now, which is one of the key differences of the i915 helpers compared to crtc helpers and a really nice additional guarantee. - Like with the plane helpers the atomic commit function waits for one vblank to pass before calling the framebuffer cleanup function. Compared to Rob's helper approach there's a bunch of upsides: - All the interfaces which can fail are called in the ->check hook (i.e. ->best_match and the various ->mode_fixup hooks). This means that drivers can just reuse those functions and don't need to move everything into ->atomic_check callbacks. If drivers have no need for additional constraint checking beyong their existing crtc helper callbacks they don't need to do anything. - The actual commit operation is properly stage: First we prepare framebuffers, which can potentially still fail (due to memory exhausting). This is important for the async case, where this must be done synchronously to correctly return errors. - The output configuration changes (done with crtc helper functions) and the plane update (using atomic plane helpers) are correctly interleaved: First we shut down any crtcs that need changing, then we update planes and finally we enable everything again. Hardware without GO bits must be more careful with ordering, which this sequence enables. - Also for hardware with shared output resources (like display PLLs) we first must shut down the old configuration before we can enable the new one. Otherwise we can hit an impossible intermediate state where there's not enough PLLs (which is the point behind atomic updates). v2: - Ensure that users of ->check update crtc_state->enable correctly. - Update the legacy state in crtc/plane structures. Eventually we want to remove that, but for now the drm core still expects this (especially the plane->fb pointer). v3: A few changes for better async handling: - Reorder the software side state commit so that it happens all before we touch the hardware. This way async support becomes very easy since we can punt all the actual hw touching to a worker thread. And as long as we synchronize with that thread (flushing or cancelling, depending upon what the driver can handle) before we commit the next software state there's no need for any locking in the worker thread at all. Which greatly simplifies things. And as long as we synchronize with all relevant threads we can have a lot of them (e.g. per-crtc for per-crtc updates) running in parallel. - Expose pre/post plane commit steps separately. We need to expose the actual hw commit step anyway for drivers to be able to implement asynchronous commit workers. But if we expose pre/post and plane commit steps individually we allow drivers to selectively use atomic helpers. - I've forgotten to call encoder/bridge ->mode_set functions, fix this. v4: Add debug output and fix a mixup between current and new state that resulted in crtcs not getting updated correctly. And in an Oops ... v5: - Be kind to driver writers in the vblank wait functions.. if thing aren't working yet, and vblank irq will never come, then let's not block forever.. especially under console-lock. - Correctly clear connector_state->best_encoder when disabling. Spotted while trying to understand a report from Rob Clark. - Only steal encoder if it actually changed, otherwise hilarity ensues if we steal from the current connector and so set the ->crtc pointer unexpectedly to NULL. Reported by Rob Clark. - Bail out in disable_outputs if an output currently doesn't have a best_encoder - this means it's already disabled. v6: Fixupe kerneldoc as reported by Paulo. And also fix up kerneldoc in drm_crtc.h. v7: Take ownership of the atomic state and clean it up with drm_atomic_state_free(). v8 Various improvements all over: - Polish code comments and kerneldoc. - Improve debug output to make sure all failure cases are logged. - Treat enabled crtc with no connectors as invalid input from userspace. - Don't ignore the return value from mode_fixup(). v9: - Improve debug output for crtc_state->mode_changed. v10: - Fixup the vblank waiting code to properly balance the vblank_get/put calls. - Better comments when checking/computing crtc->mode_changed v11: Fixup the encoder stealing logic: We can't look at encoder->crtc since that's not in the atomic state structures and might be updated asynchronously in and async commit. Instead we need to inspect all the connector states and check whether the encoder is currently in used and if so, on which crtc. v12: Review from Sean: - A few spelling fixes. - Flatten control flow indent by converting if blocks to early continue/return in 2 places. - Capture connectors_for_crtc return value in int num_connectors instead of bool has_connectors and do an explicit int->bool conversion with !!. I think the helper is more useful for drivers if it returns the number of connectors (e.g. to detect cloning configurations), so decided to keep that return value. Cc: Sean Paul <seanpaul@chromium.org> Cc: Paulo Zanoni <przanoni@gmail.com> Cc: Rob Clark <robdclark@gmail.com> Reviewed-by: Sean Paul <seanpaul@chromium.org> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2014-09-16 23:50:47 +08:00
int drm_atomic_helper_commit(struct drm_device *dev,
struct drm_atomic_state *state,
bool async);
void drm_atomic_helper_commit_pre_planes(struct drm_device *dev,
struct drm_atomic_state *state);
void drm_atomic_helper_commit_post_planes(struct drm_device *dev,
struct drm_atomic_state *old_state);
drm: Add atomic/plane helpers This is the first cut of atomic helper code. As-is it's only useful to implement a pure atomic interface for plane updates. Later patches will integrate this with the crtc helpers so that full atomic updates are possible. We also need a pile of helpers to aid drivers in transitioning from the legacy world to the shiny new atomic age. Finally we need helpers to implement legacy ioctls on top of the atomic interface. The design of the overall helpers<->driver interaction is fairly simple, but has an unfortunate large interface: - We have ->atomic_check callbacks for crtcs and planes. The idea is that connectors don't need any checking, and if they do they can adjust the relevant crtc driver-private state. So no connector hooks should be needed. Also the crtc helpers integration will do the ->best_encoder checks, so no need for that. - Framebuffer pinning needs to be done before we can commit to the hw state. This is especially important for async updates where we must pin all buffers before returning to userspace, so that really only hw failures can happen in the asynchronous worker. Hence we add ->prepare_fb and ->cleanup_fb hooks for this resources management. - The actual atomic plane commit can't fail (except hw woes), so has void return type. It has three stages: 1. Prepare all affected crtcs with crtc->atomic_begin. Drivers can use this to unset the GO bit or similar latches to prevent plane updates. 2. Update plane state by looping over all changed planes and calling plane->atomic_update. Presuming the hardware is sane and has GO bits drivers can simply bash the state into the hardware in this function. Other drivers might use this to precompute hw state for the final step. 3. Finally latch the update for the next vblank with crtc->atomic_flush. Note that this function doesn't need to wait for the vblank to happen even for the synchronous case. v2: Clear drm_<obj>_state->state to NULL when swapping in state. v3: Add TODO that we don't short-circuit plane updates for now. Likely no one will care. v4: Squash in a bit of polish that somehow landed in the wrong (later) patche. v5: Integrate atomic functions into the drm docbook and fixup the kerneldoc. v6: Fixup fixup patch squashing fumble. v7: Don't touch the legacy plane state plane->fb and plane->crtc. This is only used by the legacy ioctl code in the drm core, and that code already takes care of updating the pointers in all relevant cases. This is in stark contrast to connector->encoder->crtc links on the modeset side, which we still need to set since the core doesn't touch them. Also some more kerneldoc polish. v8: Drop outdated comment. v9: Handle the state->state pointer correctly: Only clearing the ->state pointer when assigning the state to the kms object isn't good enough. We also need to re-link the swapped out state into the drm_atomic_state structure. v10: Shuffle the misplaced docbook template hunk around that Sean spotted. Cc: Sean Paul <seanpaul@chromium.org> Reviewed-by: Sean Paul <seanpaul@chromium.org> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2014-11-05 07:14:14 +08:00
int drm_atomic_helper_prepare_planes(struct drm_device *dev,
struct drm_atomic_state *state);
void drm_atomic_helper_commit_planes(struct drm_device *dev,
struct drm_atomic_state *state);
void drm_atomic_helper_cleanup_planes(struct drm_device *dev,
struct drm_atomic_state *old_state);
void drm_atomic_helper_swap_state(struct drm_device *dev,
struct drm_atomic_state *state);
#endif /* DRM_ATOMIC_HELPER_H_ */