1 /* 2 * Copyright © 2014 Intel Corporation 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 21 * DEALINGS IN THE SOFTWARE. 22 * 23 * Authors: 24 * Daniel Vetter <daniel.vetter@ffwll.ch> 25 */ 26 27 /** 28 * DOC: frontbuffer tracking 29 * 30 * Many features require us to track changes to the currently active 31 * frontbuffer, especially rendering targeted at the frontbuffer. 32 * 33 * To be able to do so GEM tracks frontbuffers using a bitmask for all possible 34 * frontbuffer slots through i915_gem_track_fb(). The function in this file are 35 * then called when the contents of the frontbuffer are invalidated, when 36 * frontbuffer rendering has stopped again to flush out all the changes and when 37 * the frontbuffer is exchanged with a flip. Subsystems interested in 38 * frontbuffer changes (e.g. PSR, FBC, DRRS) should directly put their callbacks 39 * into the relevant places and filter for the frontbuffer slots that they are 40 * interested int. 41 * 42 * On a high level there are two types of powersaving features. The first one 43 * work like a special cache (FBC and PSR) and are interested when they should 44 * stop caching and when to restart caching. This is done by placing callbacks 45 * into the invalidate and the flush functions: At invalidate the caching must 46 * be stopped and at flush time it can be restarted. And maybe they need to know 47 * when the frontbuffer changes (e.g. when the hw doesn't initiate an invalidate 48 * and flush on its own) which can be achieved with placing callbacks into the 49 * flip functions. 50 * 51 * The other type of display power saving feature only cares about busyness 52 * (e.g. DRRS). In that case all three (invalidate, flush and flip) indicate 53 * busyness. There is no direct way to detect idleness. Instead an idle timer 54 * work delayed work should be started from the flush and flip functions and 55 * cancelled as soon as busyness is detected. 56 * 57 * Note that there's also an older frontbuffer activity tracking scheme which 58 * just tracks general activity. This is done by the various mark_busy and 59 * mark_idle functions. For display power management features using these 60 * functions is deprecated and should be avoided. 61 */ 62 63 #include <drm/drmP.h> 64 65 #include "intel_drv.h" 66 #include "intel_frontbuffer.h" 67 #include "i915_drv.h" 68 69 void __intel_fb_obj_invalidate(struct drm_i915_gem_object *obj, 70 enum fb_op_origin origin, 71 unsigned int frontbuffer_bits) 72 { 73 struct drm_i915_private *dev_priv = to_i915(obj->base.dev); 74 75 if (origin == ORIGIN_CS) { 76 lockmgr(&dev_priv->fb_tracking.lock, LK_EXCLUSIVE); 77 dev_priv->fb_tracking.busy_bits |= frontbuffer_bits; 78 dev_priv->fb_tracking.flip_bits &= ~frontbuffer_bits; 79 lockmgr(&dev_priv->fb_tracking.lock, LK_RELEASE); 80 } 81 82 intel_psr_invalidate(dev_priv, frontbuffer_bits); 83 intel_edp_drrs_invalidate(dev_priv, frontbuffer_bits); 84 intel_fbc_invalidate(dev_priv, frontbuffer_bits, origin); 85 } 86 87 /** 88 * intel_frontbuffer_flush - flush frontbuffer 89 * @dev_priv: i915 device 90 * @frontbuffer_bits: frontbuffer plane tracking bits 91 * @origin: which operation caused the flush 92 * 93 * This function gets called every time rendering on the given planes has 94 * completed and frontbuffer caching can be started again. Flushes will get 95 * delayed if they're blocked by some outstanding asynchronous rendering. 96 * 97 * Can be called without any locks held. 98 */ 99 static void intel_frontbuffer_flush(struct drm_i915_private *dev_priv, 100 unsigned frontbuffer_bits, 101 enum fb_op_origin origin) 102 { 103 /* Delay flushing when rings are still busy.*/ 104 lockmgr(&dev_priv->fb_tracking.lock, LK_EXCLUSIVE); 105 frontbuffer_bits &= ~dev_priv->fb_tracking.busy_bits; 106 lockmgr(&dev_priv->fb_tracking.lock, LK_RELEASE); 107 108 if (!frontbuffer_bits) 109 return; 110 111 intel_edp_drrs_flush(dev_priv, frontbuffer_bits); 112 intel_psr_flush(dev_priv, frontbuffer_bits, origin); 113 intel_fbc_flush(dev_priv, frontbuffer_bits, origin); 114 } 115 116 void __intel_fb_obj_flush(struct drm_i915_gem_object *obj, 117 bool retire, 118 enum fb_op_origin origin, 119 unsigned int frontbuffer_bits) 120 { 121 struct drm_i915_private *dev_priv = to_i915(obj->base.dev); 122 123 if (retire) { 124 lockmgr(&dev_priv->fb_tracking.lock, LK_EXCLUSIVE); 125 /* Filter out new bits since rendering started. */ 126 frontbuffer_bits &= dev_priv->fb_tracking.busy_bits; 127 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits; 128 lockmgr(&dev_priv->fb_tracking.lock, LK_RELEASE); 129 } 130 131 if (frontbuffer_bits) 132 intel_frontbuffer_flush(dev_priv, frontbuffer_bits, origin); 133 } 134 135 /** 136 * intel_frontbuffer_flip_prepare - prepare asynchronous frontbuffer flip 137 * @dev_priv: i915 device 138 * @frontbuffer_bits: frontbuffer plane tracking bits 139 * 140 * This function gets called after scheduling a flip on @obj. The actual 141 * frontbuffer flushing will be delayed until completion is signalled with 142 * intel_frontbuffer_flip_complete. If an invalidate happens in between this 143 * flush will be cancelled. 144 * 145 * Can be called without any locks held. 146 */ 147 void intel_frontbuffer_flip_prepare(struct drm_i915_private *dev_priv, 148 unsigned frontbuffer_bits) 149 { 150 lockmgr(&dev_priv->fb_tracking.lock, LK_EXCLUSIVE); 151 dev_priv->fb_tracking.flip_bits |= frontbuffer_bits; 152 /* Remove stale busy bits due to the old buffer. */ 153 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits; 154 lockmgr(&dev_priv->fb_tracking.lock, LK_RELEASE); 155 156 intel_psr_single_frame_update(dev_priv, frontbuffer_bits); 157 } 158 159 /** 160 * intel_frontbuffer_flip_complete - complete asynchronous frontbuffer flip 161 * @dev_priv: i915 device 162 * @frontbuffer_bits: frontbuffer plane tracking bits 163 * 164 * This function gets called after the flip has been latched and will complete 165 * on the next vblank. It will execute the flush if it hasn't been cancelled yet. 166 * 167 * Can be called without any locks held. 168 */ 169 void intel_frontbuffer_flip_complete(struct drm_i915_private *dev_priv, 170 unsigned frontbuffer_bits) 171 { 172 lockmgr(&dev_priv->fb_tracking.lock, LK_EXCLUSIVE); 173 /* Mask any cancelled flips. */ 174 frontbuffer_bits &= dev_priv->fb_tracking.flip_bits; 175 dev_priv->fb_tracking.flip_bits &= ~frontbuffer_bits; 176 lockmgr(&dev_priv->fb_tracking.lock, LK_RELEASE); 177 178 if (frontbuffer_bits) 179 intel_frontbuffer_flush(dev_priv, 180 frontbuffer_bits, ORIGIN_FLIP); 181 } 182 183 /** 184 * intel_frontbuffer_flip - synchronous frontbuffer flip 185 * @dev_priv: i915 device 186 * @frontbuffer_bits: frontbuffer plane tracking bits 187 * 188 * This function gets called after scheduling a flip on @obj. This is for 189 * synchronous plane updates which will happen on the next vblank and which will 190 * not get delayed by pending gpu rendering. 191 * 192 * Can be called without any locks held. 193 */ 194 void intel_frontbuffer_flip(struct drm_i915_private *dev_priv, 195 unsigned frontbuffer_bits) 196 { 197 lockmgr(&dev_priv->fb_tracking.lock, LK_EXCLUSIVE); 198 /* Remove stale busy bits due to the old buffer. */ 199 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits; 200 lockmgr(&dev_priv->fb_tracking.lock, LK_RELEASE); 201 202 intel_frontbuffer_flush(dev_priv, frontbuffer_bits, ORIGIN_FLIP); 203 } 204