/* * 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); } }
