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 58 #include "display/intel_dp.h" 59 60 #include "i915_drv.h" 61 #include "intel_drv.h" 62 #include "intel_fbc.h" 63 #include "intel_frontbuffer.h" 64 #include "intel_psr.h" 65 66 void __intel_fb_obj_invalidate(struct drm_i915_gem_object *obj, 67 enum fb_op_origin origin, 68 unsigned int frontbuffer_bits) 69 { 70 struct drm_i915_private *dev_priv = to_i915(obj->base.dev); 71 72 if (origin == ORIGIN_CS) { 73 spin_lock(&dev_priv->fb_tracking.lock); 74 dev_priv->fb_tracking.busy_bits |= frontbuffer_bits; 75 dev_priv->fb_tracking.flip_bits &= ~frontbuffer_bits; 76 spin_unlock(&dev_priv->fb_tracking.lock); 77 } 78 79 might_sleep(); 80 intel_psr_invalidate(dev_priv, frontbuffer_bits, origin); 81 intel_edp_drrs_invalidate(dev_priv, frontbuffer_bits); 82 intel_fbc_invalidate(dev_priv, frontbuffer_bits, origin); 83 } 84 85 /** 86 * intel_frontbuffer_flush - flush frontbuffer 87 * @dev_priv: i915 device 88 * @frontbuffer_bits: frontbuffer plane tracking bits 89 * @origin: which operation caused the flush 90 * 91 * This function gets called every time rendering on the given planes has 92 * completed and frontbuffer caching can be started again. Flushes will get 93 * delayed if they're blocked by some outstanding asynchronous rendering. 94 * 95 * Can be called without any locks held. 96 */ 97 static void intel_frontbuffer_flush(struct drm_i915_private *dev_priv, 98 unsigned frontbuffer_bits, 99 enum fb_op_origin origin) 100 { 101 /* Delay flushing when rings are still busy.*/ 102 spin_lock(&dev_priv->fb_tracking.lock); 103 frontbuffer_bits &= ~dev_priv->fb_tracking.busy_bits; 104 spin_unlock(&dev_priv->fb_tracking.lock); 105 106 if (!frontbuffer_bits) 107 return; 108 109 might_sleep(); 110 intel_edp_drrs_flush(dev_priv, frontbuffer_bits); 111 intel_psr_flush(dev_priv, frontbuffer_bits, origin); 112 intel_fbc_flush(dev_priv, frontbuffer_bits, origin); 113 } 114 115 void __intel_fb_obj_flush(struct drm_i915_gem_object *obj, 116 enum fb_op_origin origin, 117 unsigned int frontbuffer_bits) 118 { 119 struct drm_i915_private *dev_priv = to_i915(obj->base.dev); 120 121 if (origin == ORIGIN_CS) { 122 spin_lock(&dev_priv->fb_tracking.lock); 123 /* Filter out new bits since rendering started. */ 124 frontbuffer_bits &= dev_priv->fb_tracking.busy_bits; 125 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits; 126 spin_unlock(&dev_priv->fb_tracking.lock); 127 } 128 129 if (frontbuffer_bits) 130 intel_frontbuffer_flush(dev_priv, frontbuffer_bits, origin); 131 } 132 133 /** 134 * intel_frontbuffer_flip_prepare - prepare asynchronous frontbuffer flip 135 * @dev_priv: i915 device 136 * @frontbuffer_bits: frontbuffer plane tracking bits 137 * 138 * This function gets called after scheduling a flip on @obj. The actual 139 * frontbuffer flushing will be delayed until completion is signalled with 140 * intel_frontbuffer_flip_complete. If an invalidate happens in between this 141 * flush will be cancelled. 142 * 143 * Can be called without any locks held. 144 */ 145 void intel_frontbuffer_flip_prepare(struct drm_i915_private *dev_priv, 146 unsigned frontbuffer_bits) 147 { 148 spin_lock(&dev_priv->fb_tracking.lock); 149 dev_priv->fb_tracking.flip_bits |= frontbuffer_bits; 150 /* Remove stale busy bits due to the old buffer. */ 151 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits; 152 spin_unlock(&dev_priv->fb_tracking.lock); 153 } 154 155 /** 156 * intel_frontbuffer_flip_complete - complete asynchronous frontbuffer flip 157 * @dev_priv: i915 device 158 * @frontbuffer_bits: frontbuffer plane tracking bits 159 * 160 * This function gets called after the flip has been latched and will complete 161 * on the next vblank. It will execute the flush if it hasn't been cancelled yet. 162 * 163 * Can be called without any locks held. 164 */ 165 void intel_frontbuffer_flip_complete(struct drm_i915_private *dev_priv, 166 unsigned frontbuffer_bits) 167 { 168 spin_lock(&dev_priv->fb_tracking.lock); 169 /* Mask any cancelled flips. */ 170 frontbuffer_bits &= dev_priv->fb_tracking.flip_bits; 171 dev_priv->fb_tracking.flip_bits &= ~frontbuffer_bits; 172 spin_unlock(&dev_priv->fb_tracking.lock); 173 174 if (frontbuffer_bits) 175 intel_frontbuffer_flush(dev_priv, 176 frontbuffer_bits, ORIGIN_FLIP); 177 } 178 179 /** 180 * intel_frontbuffer_flip - synchronous frontbuffer flip 181 * @dev_priv: i915 device 182 * @frontbuffer_bits: frontbuffer plane tracking bits 183 * 184 * This function gets called after scheduling a flip on @obj. This is for 185 * synchronous plane updates which will happen on the next vblank and which will 186 * not get delayed by pending gpu rendering. 187 * 188 * Can be called without any locks held. 189 */ 190 void intel_frontbuffer_flip(struct drm_i915_private *dev_priv, 191 unsigned frontbuffer_bits) 192 { 193 spin_lock(&dev_priv->fb_tracking.lock); 194 /* Remove stale busy bits due to the old buffer. */ 195 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits; 196 spin_unlock(&dev_priv->fb_tracking.lock); 197 198 intel_frontbuffer_flush(dev_priv, frontbuffer_bits, ORIGIN_FLIP); 199 } 200