diff options
Diffstat (limited to 'drivers/gpu/drm/i915/display/intel_frontbuffer.c')
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_frontbuffer.c | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_frontbuffer.c b/drivers/gpu/drm/i915/display/intel_frontbuffer.c new file mode 100644 index 000000000000..03c4978fa5ec --- /dev/null +++ b/drivers/gpu/drm/i915/display/intel_frontbuffer.c @@ -0,0 +1,256 @@ +/* + * Copyright © 2014 Intel Corporation + * + * 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 (including the next + * paragraph) 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 AUTHORS OR COPYRIGHT HOLDERS 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: + * Daniel Vetter <daniel.vetter@ffwll.ch> + */ + +/** + * DOC: frontbuffer tracking + * + * Many features require us to track changes to the currently active + * frontbuffer, especially rendering targeted at the frontbuffer. + * + * To be able to do so we track frontbuffers using a bitmask for all possible + * frontbuffer slots through intel_frontbuffer_track(). The functions in this + * file are then called when the contents of the frontbuffer are invalidated, + * when frontbuffer rendering has stopped again to flush out all the changes + * and when the frontbuffer is exchanged with a flip. Subsystems interested in + * frontbuffer changes (e.g. PSR, FBC, DRRS) should directly put their callbacks + * into the relevant places and filter for the frontbuffer slots that they are + * interested int. + * + * On a high level there are two types of powersaving features. The first one + * work like a special cache (FBC and PSR) and are interested when they should + * stop caching and when to restart caching. This is done by placing callbacks + * into the invalidate and the flush functions: At invalidate the caching must + * be stopped and at flush time it can be restarted. And maybe they need to know + * when the frontbuffer changes (e.g. when the hw doesn't initiate an invalidate + * and flush on its own) which can be achieved with placing callbacks into the + * flip functions. + * + * The other type of display power saving feature only cares about busyness + * (e.g. DRRS). In that case all three (invalidate, flush and flip) indicate + * busyness. There is no direct way to detect idleness. Instead an idle timer + * work delayed work should be started from the flush and flip functions and + * cancelled as soon as busyness is detected. + */ + +#include <drm/drm_gem.h> +#include <drm/drm_print.h> + +#include "intel_bo.h" +#include "intel_display_trace.h" +#include "intel_display_types.h" +#include "intel_dp.h" +#include "intel_drrs.h" +#include "intel_fbc.h" +#include "intel_frontbuffer.h" +#include "intel_psr.h" +#include "intel_tdf.h" + +/** + * frontbuffer_flush - flush frontbuffer + * @display: display device + * @frontbuffer_bits: frontbuffer plane tracking bits + * @origin: which operation caused the flush + * + * This function gets called every time rendering on the given planes has + * completed and frontbuffer caching can be started again. Flushes will get + * delayed if they're blocked by some outstanding asynchronous rendering. + * + * Can be called without any locks held. + */ +static void frontbuffer_flush(struct intel_display *display, + unsigned int frontbuffer_bits, + enum fb_op_origin origin) +{ + /* Delay flushing when rings are still busy.*/ + spin_lock(&display->fb_tracking.lock); + frontbuffer_bits &= ~display->fb_tracking.busy_bits; + spin_unlock(&display->fb_tracking.lock); + + if (!frontbuffer_bits) + return; + + trace_intel_frontbuffer_flush(display, frontbuffer_bits, origin); + + might_sleep(); + intel_td_flush(display); + intel_drrs_flush(display, frontbuffer_bits); + intel_psr_flush(display, frontbuffer_bits, origin); + intel_fbc_flush(display, frontbuffer_bits, origin); +} + +/** + * intel_frontbuffer_flip - synchronous frontbuffer flip + * @display: display device + * @frontbuffer_bits: frontbuffer plane tracking bits + * + * This function gets called after scheduling a flip on @obj. This is for + * synchronous plane updates which will happen on the next vblank and which will + * not get delayed by pending gpu rendering. + * + * Can be called without any locks held. + */ +void intel_frontbuffer_flip(struct intel_display *display, + unsigned frontbuffer_bits) +{ + spin_lock(&display->fb_tracking.lock); + /* Remove stale busy bits due to the old buffer. */ + display->fb_tracking.busy_bits &= ~frontbuffer_bits; + spin_unlock(&display->fb_tracking.lock); + + frontbuffer_flush(display, frontbuffer_bits, ORIGIN_FLIP); +} + +void __intel_fb_invalidate(struct intel_frontbuffer *front, + enum fb_op_origin origin, + unsigned int frontbuffer_bits) +{ + struct intel_display *display = front->display; + + if (origin == ORIGIN_CS) { + spin_lock(&display->fb_tracking.lock); + display->fb_tracking.busy_bits |= frontbuffer_bits; + spin_unlock(&display->fb_tracking.lock); + } + + trace_intel_frontbuffer_invalidate(display, frontbuffer_bits, origin); + + might_sleep(); + intel_psr_invalidate(display, frontbuffer_bits, origin); + intel_drrs_invalidate(display, frontbuffer_bits); + intel_fbc_invalidate(display, frontbuffer_bits, origin); +} + +void __intel_fb_flush(struct intel_frontbuffer *front, + enum fb_op_origin origin, + unsigned int frontbuffer_bits) +{ + struct intel_display *display = front->display; + + if (origin == ORIGIN_DIRTYFB) + intel_bo_frontbuffer_flush_for_display(front); + + if (origin == ORIGIN_CS) { + spin_lock(&display->fb_tracking.lock); + /* Filter out new bits since rendering started. */ + frontbuffer_bits &= display->fb_tracking.busy_bits; + display->fb_tracking.busy_bits &= ~frontbuffer_bits; + spin_unlock(&display->fb_tracking.lock); + } + + if (frontbuffer_bits) + frontbuffer_flush(display, frontbuffer_bits, origin); +} + +static void intel_frontbuffer_ref(struct intel_frontbuffer *front) +{ + intel_bo_frontbuffer_ref(front); +} + +static void intel_frontbuffer_flush_work(struct work_struct *work) +{ + struct intel_frontbuffer *front = + container_of(work, struct intel_frontbuffer, flush_work); + + intel_frontbuffer_flush(front, ORIGIN_DIRTYFB); + intel_frontbuffer_put(front); +} + +/** + * intel_frontbuffer_queue_flush - queue flushing frontbuffer object + * @front: GEM object to flush + * + * This function is targeted for our dirty callback for queueing flush when + * dma fence is signals + */ +void intel_frontbuffer_queue_flush(struct intel_frontbuffer *front) +{ + if (!front) + return; + + intel_frontbuffer_ref(front); + if (!schedule_work(&front->flush_work)) + intel_frontbuffer_put(front); +} + +void intel_frontbuffer_init(struct intel_frontbuffer *front, struct drm_device *drm) +{ + front->display = to_intel_display(drm); + atomic_set(&front->bits, 0); + INIT_WORK(&front->flush_work, intel_frontbuffer_flush_work); +} + +void intel_frontbuffer_fini(struct intel_frontbuffer *front) +{ + drm_WARN_ON(front->display->drm, atomic_read(&front->bits)); +} + +struct intel_frontbuffer *intel_frontbuffer_get(struct drm_gem_object *obj) +{ + return intel_bo_frontbuffer_get(obj); +} + +void intel_frontbuffer_put(struct intel_frontbuffer *front) +{ + intel_bo_frontbuffer_put(front); +} + +/** + * intel_frontbuffer_track - update frontbuffer tracking + * @old: current buffer for the frontbuffer slots + * @new: new buffer for the frontbuffer slots + * @frontbuffer_bits: bitmask of frontbuffer slots + * + * This updates the frontbuffer tracking bits @frontbuffer_bits by clearing them + * from @old and setting them in @new. Both @old and @new can be NULL. + */ +void intel_frontbuffer_track(struct intel_frontbuffer *old, + struct intel_frontbuffer *new, + unsigned int frontbuffer_bits) +{ + /* + * Control of individual bits within the mask are guarded by + * the owning plane->mutex, i.e. we can never see concurrent + * manipulation of individual bits. But since the bitfield as a whole + * is updated using RMW, we need to use atomics in order to update + * the bits. + */ + BUILD_BUG_ON(INTEL_FRONTBUFFER_BITS_PER_PIPE * I915_MAX_PIPES > + BITS_PER_TYPE(atomic_t)); + BUILD_BUG_ON(INTEL_FRONTBUFFER_BITS_PER_PIPE * I915_MAX_PIPES > 32); + BUILD_BUG_ON(I915_MAX_PLANES > INTEL_FRONTBUFFER_BITS_PER_PIPE); + + if (old) { + drm_WARN_ON(old->display->drm, + !(atomic_read(&old->bits) & frontbuffer_bits)); + atomic_andnot(frontbuffer_bits, &old->bits); + } + + if (new) { + drm_WARN_ON(new->display->drm, + atomic_read(&new->bits) & frontbuffer_bits); + atomic_or(frontbuffer_bits, &new->bits); + } +} |