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1/*2 * Copyright © 2014 Intel Corporation3 *4 * Permission is hereby granted, free of charge, to any person obtaining a5 * copy of this software and associated documentation files (the "Software"),6 * to deal in the Software without restriction, including without limitation7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,8 * and/or sell copies of the Software, and to permit persons to whom the9 * Software is furnished to do so, subject to the following conditions:10 *11 * The above copyright notice and this permission notice (including the next12 * paragraph) shall be included in all copies or substantial portions of the13 * Software.14 *15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER21 * DEALINGS IN THE SOFTWARE.22 *23 * Authors:24 * Daniel Vetter <daniel.vetter@ffwll.ch>25 */26 27/**28 * DOC: frontbuffer tracking29 *30 * Many features require us to track changes to the currently active31 * frontbuffer, especially rendering targeted at the frontbuffer.32 *33 * To be able to do so we track frontbuffers using a bitmask for all possible34 * frontbuffer slots through intel_frontbuffer_track(). The functions in this35 * file are then called when the contents of the frontbuffer are invalidated,36 * when frontbuffer rendering has stopped again to flush out all the changes37 * and when the frontbuffer is exchanged with a flip. Subsystems interested in38 * frontbuffer changes (e.g. PSR, FBC, DRRS) should directly put their callbacks39 * into the relevant places and filter for the frontbuffer slots that they are40 * interested int.41 *42 * On a high level there are two types of powersaving features. The first one43 * work like a special cache (FBC and PSR) and are interested when they should44 * stop caching and when to restart caching. This is done by placing callbacks45 * into the invalidate and the flush functions: At invalidate the caching must46 * be stopped and at flush time it can be restarted. And maybe they need to know47 * when the frontbuffer changes (e.g. when the hw doesn't initiate an invalidate48 * and flush on its own) which can be achieved with placing callbacks into the49 * flip functions.50 *51 * The other type of display power saving feature only cares about busyness52 * (e.g. DRRS). In that case all three (invalidate, flush and flip) indicate53 * busyness. There is no direct way to detect idleness. Instead an idle timer54 * work delayed work should be started from the flush and flip functions and55 * cancelled as soon as busyness is detected.56 */57 58#include "gem/i915_gem_object_frontbuffer.h"59#include "i915_active.h"60#include "i915_drv.h"61#include "intel_display_trace.h"62#include "intel_display_types.h"63#include "intel_dp.h"64#include "intel_drrs.h"65#include "intel_fbc.h"66#include "intel_frontbuffer.h"67#include "intel_psr.h"68#include "intel_tdf.h"69 70/**71 * frontbuffer_flush - flush frontbuffer72 * @i915: i915 device73 * @frontbuffer_bits: frontbuffer plane tracking bits74 * @origin: which operation caused the flush75 *76 * This function gets called every time rendering on the given planes has77 * completed and frontbuffer caching can be started again. Flushes will get78 * delayed if they're blocked by some outstanding asynchronous rendering.79 *80 * Can be called without any locks held.81 */82static void frontbuffer_flush(struct drm_i915_private *i915,83 unsigned int frontbuffer_bits,84 enum fb_op_origin origin)85{86 struct intel_display *display = &i915->display;87 88 /* Delay flushing when rings are still busy.*/89 spin_lock(&i915->display.fb_tracking.lock);90 frontbuffer_bits &= ~i915->display.fb_tracking.busy_bits;91 spin_unlock(&i915->display.fb_tracking.lock);92 93 if (!frontbuffer_bits)94 return;95 96 trace_intel_frontbuffer_flush(i915, frontbuffer_bits, origin);97 98 might_sleep();99 intel_td_flush(i915);100 intel_drrs_flush(i915, frontbuffer_bits);101 intel_psr_flush(display, frontbuffer_bits, origin);102 intel_fbc_flush(i915, frontbuffer_bits, origin);103}104 105/**106 * intel_frontbuffer_flip_prepare - prepare asynchronous frontbuffer flip107 * @i915: i915 device108 * @frontbuffer_bits: frontbuffer plane tracking bits109 *110 * This function gets called after scheduling a flip on @obj. The actual111 * frontbuffer flushing will be delayed until completion is signalled with112 * intel_frontbuffer_flip_complete. If an invalidate happens in between this113 * flush will be cancelled.114 *115 * Can be called without any locks held.116 */117void intel_frontbuffer_flip_prepare(struct drm_i915_private *i915,118 unsigned frontbuffer_bits)119{120 spin_lock(&i915->display.fb_tracking.lock);121 i915->display.fb_tracking.flip_bits |= frontbuffer_bits;122 /* Remove stale busy bits due to the old buffer. */123 i915->display.fb_tracking.busy_bits &= ~frontbuffer_bits;124 spin_unlock(&i915->display.fb_tracking.lock);125}126 127/**128 * intel_frontbuffer_flip_complete - complete asynchronous frontbuffer flip129 * @i915: i915 device130 * @frontbuffer_bits: frontbuffer plane tracking bits131 *132 * This function gets called after the flip has been latched and will complete133 * on the next vblank. It will execute the flush if it hasn't been cancelled yet.134 *135 * Can be called without any locks held.136 */137void intel_frontbuffer_flip_complete(struct drm_i915_private *i915,138 unsigned frontbuffer_bits)139{140 spin_lock(&i915->display.fb_tracking.lock);141 /* Mask any cancelled flips. */142 frontbuffer_bits &= i915->display.fb_tracking.flip_bits;143 i915->display.fb_tracking.flip_bits &= ~frontbuffer_bits;144 spin_unlock(&i915->display.fb_tracking.lock);145 146 if (frontbuffer_bits)147 frontbuffer_flush(i915, frontbuffer_bits, ORIGIN_FLIP);148}149 150/**151 * intel_frontbuffer_flip - synchronous frontbuffer flip152 * @i915: i915 device153 * @frontbuffer_bits: frontbuffer plane tracking bits154 *155 * This function gets called after scheduling a flip on @obj. This is for156 * synchronous plane updates which will happen on the next vblank and which will157 * not get delayed by pending gpu rendering.158 *159 * Can be called without any locks held.160 */161void intel_frontbuffer_flip(struct drm_i915_private *i915,162 unsigned frontbuffer_bits)163{164 spin_lock(&i915->display.fb_tracking.lock);165 /* Remove stale busy bits due to the old buffer. */166 i915->display.fb_tracking.busy_bits &= ~frontbuffer_bits;167 spin_unlock(&i915->display.fb_tracking.lock);168 169 frontbuffer_flush(i915, frontbuffer_bits, ORIGIN_FLIP);170}171 172void __intel_fb_invalidate(struct intel_frontbuffer *front,173 enum fb_op_origin origin,174 unsigned int frontbuffer_bits)175{176 struct drm_i915_private *i915 = intel_bo_to_i915(front->obj);177 struct intel_display *display = &i915->display;178 179 if (origin == ORIGIN_CS) {180 spin_lock(&i915->display.fb_tracking.lock);181 i915->display.fb_tracking.busy_bits |= frontbuffer_bits;182 i915->display.fb_tracking.flip_bits &= ~frontbuffer_bits;183 spin_unlock(&i915->display.fb_tracking.lock);184 }185 186 trace_intel_frontbuffer_invalidate(i915, frontbuffer_bits, origin);187 188 might_sleep();189 intel_psr_invalidate(display, frontbuffer_bits, origin);190 intel_drrs_invalidate(i915, frontbuffer_bits);191 intel_fbc_invalidate(i915, frontbuffer_bits, origin);192}193 194void __intel_fb_flush(struct intel_frontbuffer *front,195 enum fb_op_origin origin,196 unsigned int frontbuffer_bits)197{198 struct drm_i915_private *i915 = intel_bo_to_i915(front->obj);199 200 if (origin == ORIGIN_CS) {201 spin_lock(&i915->display.fb_tracking.lock);202 /* Filter out new bits since rendering started. */203 frontbuffer_bits &= i915->display.fb_tracking.busy_bits;204 i915->display.fb_tracking.busy_bits &= ~frontbuffer_bits;205 spin_unlock(&i915->display.fb_tracking.lock);206 }207 208 if (frontbuffer_bits)209 frontbuffer_flush(i915, frontbuffer_bits, origin);210}211 212static void intel_frontbuffer_flush_work(struct work_struct *work)213{214 struct intel_frontbuffer *front =215 container_of(work, struct intel_frontbuffer, flush_work);216 217 i915_gem_object_flush_if_display(front->obj);218 intel_frontbuffer_flush(front, ORIGIN_DIRTYFB);219 intel_frontbuffer_put(front);220}221 222/**223 * intel_frontbuffer_queue_flush - queue flushing frontbuffer object224 * @front: GEM object to flush225 *226 * This function is targeted for our dirty callback for queueing flush when227 * dma fence is signales228 */229void intel_frontbuffer_queue_flush(struct intel_frontbuffer *front)230{231 if (!front)232 return;233 234 kref_get(&front->ref);235 if (!schedule_work(&front->flush_work))236 intel_frontbuffer_put(front);237}238 239static int frontbuffer_active(struct i915_active *ref)240{241 struct intel_frontbuffer *front =242 container_of(ref, typeof(*front), write);243 244 kref_get(&front->ref);245 return 0;246}247 248static void frontbuffer_retire(struct i915_active *ref)249{250 struct intel_frontbuffer *front =251 container_of(ref, typeof(*front), write);252 253 intel_frontbuffer_flush(front, ORIGIN_CS);254 intel_frontbuffer_put(front);255}256 257static void frontbuffer_release(struct kref *ref)258 __releases(&intel_bo_to_i915(front->obj)->display.fb_tracking.lock)259{260 struct intel_frontbuffer *ret, *front =261 container_of(ref, typeof(*front), ref);262 struct drm_i915_gem_object *obj = front->obj;263 264 drm_WARN_ON(&intel_bo_to_i915(obj)->drm, atomic_read(&front->bits));265 266 i915_ggtt_clear_scanout(obj);267 268 ret = i915_gem_object_set_frontbuffer(obj, NULL);269 drm_WARN_ON(&intel_bo_to_i915(obj)->drm, ret);270 spin_unlock(&intel_bo_to_i915(obj)->display.fb_tracking.lock);271 272 i915_active_fini(&front->write);273 kfree_rcu(front, rcu);274}275 276struct intel_frontbuffer *277intel_frontbuffer_get(struct drm_i915_gem_object *obj)278{279 struct drm_i915_private *i915 = intel_bo_to_i915(obj);280 struct intel_frontbuffer *front, *cur;281 282 front = i915_gem_object_get_frontbuffer(obj);283 if (front)284 return front;285 286 front = kmalloc(sizeof(*front), GFP_KERNEL);287 if (!front)288 return NULL;289 290 front->obj = obj;291 kref_init(&front->ref);292 atomic_set(&front->bits, 0);293 i915_active_init(&front->write,294 frontbuffer_active,295 frontbuffer_retire,296 I915_ACTIVE_RETIRE_SLEEPS);297 INIT_WORK(&front->flush_work, intel_frontbuffer_flush_work);298 299 spin_lock(&i915->display.fb_tracking.lock);300 cur = i915_gem_object_set_frontbuffer(obj, front);301 spin_unlock(&i915->display.fb_tracking.lock);302 if (cur != front)303 kfree(front);304 return cur;305}306 307void intel_frontbuffer_put(struct intel_frontbuffer *front)308{309 kref_put_lock(&front->ref,310 frontbuffer_release,311 &intel_bo_to_i915(front->obj)->display.fb_tracking.lock);312}313 314/**315 * intel_frontbuffer_track - update frontbuffer tracking316 * @old: current buffer for the frontbuffer slots317 * @new: new buffer for the frontbuffer slots318 * @frontbuffer_bits: bitmask of frontbuffer slots319 *320 * This updates the frontbuffer tracking bits @frontbuffer_bits by clearing them321 * from @old and setting them in @new. Both @old and @new can be NULL.322 */323void intel_frontbuffer_track(struct intel_frontbuffer *old,324 struct intel_frontbuffer *new,325 unsigned int frontbuffer_bits)326{327 /*328 * Control of individual bits within the mask are guarded by329 * the owning plane->mutex, i.e. we can never see concurrent330 * manipulation of individual bits. But since the bitfield as a whole331 * is updated using RMW, we need to use atomics in order to update332 * the bits.333 */334 BUILD_BUG_ON(INTEL_FRONTBUFFER_BITS_PER_PIPE * I915_MAX_PIPES >335 BITS_PER_TYPE(atomic_t));336 BUILD_BUG_ON(INTEL_FRONTBUFFER_BITS_PER_PIPE * I915_MAX_PIPES > 32);337 BUILD_BUG_ON(I915_MAX_PLANES > INTEL_FRONTBUFFER_BITS_PER_PIPE);338 339 if (old) {340 drm_WARN_ON(&intel_bo_to_i915(old->obj)->drm,341 !(atomic_read(&old->bits) & frontbuffer_bits));342 atomic_andnot(frontbuffer_bits, &old->bits);343 }344 345 if (new) {346 drm_WARN_ON(&intel_bo_to_i915(new->obj)->drm,347 atomic_read(&new->bits) & frontbuffer_bits);348 atomic_or(frontbuffer_bits, &new->bits);349 }350}351