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 "i915_drv.h" 67 68 /** 69 * intel_fb_obj_invalidate - invalidate frontbuffer object 70 * @obj: GEM object to invalidate 71 * @origin: which operation caused the invalidation 72 * 73 * This function gets called every time rendering on the given object starts and 74 * frontbuffer caching (fbc, low refresh rate for DRRS, panel self refresh) must 75 * be invalidated. For ORIGIN_CS any subsequent invalidation will be delayed 76 * until the rendering completes or a flip on this frontbuffer plane is 77 * scheduled. 78 */ 79 void intel_fb_obj_invalidate(struct drm_i915_gem_object *obj, 80 enum fb_op_origin origin) 81 { 82 struct drm_device *dev = obj->base.dev; 83 struct drm_i915_private *dev_priv = to_i915(dev); 84 85 WARN_ON(!mutex_is_locked(&dev->struct_mutex)); 86 87 if (!obj->frontbuffer_bits) 88 return; 89 90 if (origin == ORIGIN_CS) { 91 mutex_lock(&dev_priv->fb_tracking.lock); 92 dev_priv->fb_tracking.busy_bits 93 |= obj->frontbuffer_bits; 94 dev_priv->fb_tracking.flip_bits 95 &= ~obj->frontbuffer_bits; 96 mutex_unlock(&dev_priv->fb_tracking.lock); 97 } 98 99 intel_psr_invalidate(dev, obj->frontbuffer_bits); 100 intel_edp_drrs_invalidate(dev, obj->frontbuffer_bits); 101 intel_fbc_invalidate(dev_priv, obj->frontbuffer_bits, origin); 102 } 103 104 /** 105 * intel_frontbuffer_flush - flush frontbuffer 106 * @dev: DRM device 107 * @frontbuffer_bits: frontbuffer plane tracking bits 108 * @origin: which operation caused the flush 109 * 110 * This function gets called every time rendering on the given planes has 111 * completed and frontbuffer caching can be started again. Flushes will get 112 * delayed if they're blocked by some outstanding asynchronous rendering. 113 * 114 * Can be called without any locks held. 115 */ 116 static void intel_frontbuffer_flush(struct drm_device *dev, 117 unsigned frontbuffer_bits, 118 enum fb_op_origin origin) 119 { 120 struct drm_i915_private *dev_priv = to_i915(dev); 121 122 /* Delay flushing when rings are still busy.*/ 123 mutex_lock(&dev_priv->fb_tracking.lock); 124 frontbuffer_bits &= ~dev_priv->fb_tracking.busy_bits; 125 mutex_unlock(&dev_priv->fb_tracking.lock); 126 127 if (!frontbuffer_bits) 128 return; 129 130 intel_edp_drrs_flush(dev, frontbuffer_bits); 131 intel_psr_flush(dev, frontbuffer_bits, origin); 132 intel_fbc_flush(dev_priv, frontbuffer_bits, origin); 133 } 134 135 /** 136 * intel_fb_obj_flush - flush frontbuffer object 137 * @obj: GEM object to flush 138 * @retire: set when retiring asynchronous rendering 139 * @origin: which operation caused the flush 140 * 141 * This function gets called every time rendering on the given object has 142 * completed and frontbuffer caching can be started again. If @retire is true 143 * then any delayed flushes will be unblocked. 144 */ 145 void intel_fb_obj_flush(struct drm_i915_gem_object *obj, 146 bool retire, enum fb_op_origin origin) 147 { 148 struct drm_device *dev = obj->base.dev; 149 struct drm_i915_private *dev_priv = to_i915(dev); 150 unsigned frontbuffer_bits; 151 152 WARN_ON(!mutex_is_locked(&dev->struct_mutex)); 153 154 if (!obj->frontbuffer_bits) 155 return; 156 157 frontbuffer_bits = obj->frontbuffer_bits; 158 159 if (retire) { 160 mutex_lock(&dev_priv->fb_tracking.lock); 161 /* Filter out new bits since rendering started. */ 162 frontbuffer_bits &= dev_priv->fb_tracking.busy_bits; 163 164 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits; 165 mutex_unlock(&dev_priv->fb_tracking.lock); 166 } 167 168 intel_frontbuffer_flush(dev, frontbuffer_bits, origin); 169 } 170 171 /** 172 * intel_frontbuffer_flip_prepare - prepare asynchronous frontbuffer flip 173 * @dev: DRM device 174 * @frontbuffer_bits: frontbuffer plane tracking bits 175 * 176 * This function gets called after scheduling a flip on @obj. The actual 177 * frontbuffer flushing will be delayed until completion is signalled with 178 * intel_frontbuffer_flip_complete. If an invalidate happens in between this 179 * flush will be cancelled. 180 * 181 * Can be called without any locks held. 182 */ 183 void intel_frontbuffer_flip_prepare(struct drm_device *dev, 184 unsigned frontbuffer_bits) 185 { 186 struct drm_i915_private *dev_priv = to_i915(dev); 187 188 mutex_lock(&dev_priv->fb_tracking.lock); 189 dev_priv->fb_tracking.flip_bits |= frontbuffer_bits; 190 /* Remove stale busy bits due to the old buffer. */ 191 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits; 192 mutex_unlock(&dev_priv->fb_tracking.lock); 193 194 intel_psr_single_frame_update(dev, frontbuffer_bits); 195 } 196 197 /** 198 * intel_frontbuffer_flip_complete - complete asynchronous frontbuffer flip 199 * @dev: DRM device 200 * @frontbuffer_bits: frontbuffer plane tracking bits 201 * 202 * This function gets called after the flip has been latched and will complete 203 * on the next vblank. It will execute the flush if it hasn't been cancelled yet. 204 * 205 * Can be called without any locks held. 206 */ 207 void intel_frontbuffer_flip_complete(struct drm_device *dev, 208 unsigned frontbuffer_bits) 209 { 210 struct drm_i915_private *dev_priv = to_i915(dev); 211 212 mutex_lock(&dev_priv->fb_tracking.lock); 213 /* Mask any cancelled flips. */ 214 frontbuffer_bits &= dev_priv->fb_tracking.flip_bits; 215 dev_priv->fb_tracking.flip_bits &= ~frontbuffer_bits; 216 mutex_unlock(&dev_priv->fb_tracking.lock); 217 218 intel_frontbuffer_flush(dev, frontbuffer_bits, ORIGIN_FLIP); 219 } 220 221 /** 222 * intel_frontbuffer_flip - synchronous frontbuffer flip 223 * @dev: DRM device 224 * @frontbuffer_bits: frontbuffer plane tracking bits 225 * 226 * This function gets called after scheduling a flip on @obj. This is for 227 * synchronous plane updates which will happen on the next vblank and which will 228 * not get delayed by pending gpu rendering. 229 * 230 * Can be called without any locks held. 231 */ 232 void intel_frontbuffer_flip(struct drm_device *dev, 233 unsigned frontbuffer_bits) 234 { 235 struct drm_i915_private *dev_priv = to_i915(dev); 236 237 mutex_lock(&dev_priv->fb_tracking.lock); 238 /* Remove stale busy bits due to the old buffer. */ 239 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits; 240 mutex_unlock(&dev_priv->fb_tracking.lock); 241 242 intel_frontbuffer_flush(dev, frontbuffer_bits, ORIGIN_FLIP); 243 } 244