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 static void intel_increase_pllclock(struct drm_device *dev, 69 enum i915_pipe pipe) 70 { 71 struct drm_i915_private *dev_priv = dev->dev_private; 72 int dpll_reg = DPLL(pipe); 73 int dpll; 74 75 if (!HAS_GMCH_DISPLAY(dev)) 76 return; 77 78 if (!dev_priv->lvds_downclock_avail) 79 return; 80 81 dpll = I915_READ(dpll_reg); 82 if (!HAS_PIPE_CXSR(dev) && (dpll & DISPLAY_RATE_SELECT_FPA1)) { 83 DRM_DEBUG_DRIVER("upclocking LVDS\n"); 84 85 assert_panel_unlocked(dev_priv, pipe); 86 87 dpll &= ~DISPLAY_RATE_SELECT_FPA1; 88 I915_WRITE(dpll_reg, dpll); 89 intel_wait_for_vblank(dev, pipe); 90 91 dpll = I915_READ(dpll_reg); 92 if (dpll & DISPLAY_RATE_SELECT_FPA1) 93 DRM_DEBUG_DRIVER("failed to upclock LVDS!\n"); 94 } 95 } 96 97 /** 98 * intel_mark_fb_busy - mark given planes as busy 99 * @dev: DRM device 100 * @frontbuffer_bits: bits for the affected planes 101 * @ring: optional ring for asynchronous commands 102 * 103 * This function gets called every time the screen contents change. It can be 104 * used to keep e.g. the update rate at the nominal refresh rate with DRRS. 105 */ 106 static void intel_mark_fb_busy(struct drm_device *dev, 107 unsigned frontbuffer_bits, 108 struct intel_engine_cs *ring) 109 { 110 struct drm_i915_private *dev_priv = dev->dev_private; 111 enum i915_pipe pipe; 112 113 for_each_pipe(dev_priv, pipe) { 114 if (!(frontbuffer_bits & INTEL_FRONTBUFFER_ALL_MASK(pipe))) 115 continue; 116 117 intel_increase_pllclock(dev, pipe); 118 } 119 } 120 121 /** 122 * intel_fb_obj_invalidate - invalidate frontbuffer object 123 * @obj: GEM object to invalidate 124 * @ring: set for asynchronous rendering 125 * @origin: which operation caused the invalidation 126 * 127 * This function gets called every time rendering on the given object starts and 128 * frontbuffer caching (fbc, low refresh rate for DRRS, panel self refresh) must 129 * be invalidated. If @ring is non-NULL any subsequent invalidation will be delayed 130 * until the rendering completes or a flip on this frontbuffer plane is 131 * scheduled. 132 */ 133 void intel_fb_obj_invalidate(struct drm_i915_gem_object *obj, 134 struct intel_engine_cs *ring, 135 enum fb_op_origin origin) 136 { 137 struct drm_device *dev = obj->base.dev; 138 struct drm_i915_private *dev_priv = dev->dev_private; 139 140 WARN_ON(!mutex_is_locked(&dev->struct_mutex)); 141 142 if (!obj->frontbuffer_bits) 143 return; 144 145 if (ring) { 146 mutex_lock(&dev_priv->fb_tracking.lock); 147 dev_priv->fb_tracking.busy_bits 148 |= obj->frontbuffer_bits; 149 dev_priv->fb_tracking.flip_bits 150 &= ~obj->frontbuffer_bits; 151 mutex_unlock(&dev_priv->fb_tracking.lock); 152 } 153 154 intel_mark_fb_busy(dev, obj->frontbuffer_bits, ring); 155 156 intel_psr_invalidate(dev, obj->frontbuffer_bits); 157 intel_edp_drrs_invalidate(dev, obj->frontbuffer_bits); 158 intel_fbc_invalidate(dev_priv, obj->frontbuffer_bits, origin); 159 } 160 161 /** 162 * intel_frontbuffer_flush - flush frontbuffer 163 * @dev: DRM device 164 * @frontbuffer_bits: frontbuffer plane tracking bits 165 * 166 * This function gets called every time rendering on the given planes has 167 * completed and frontbuffer caching can be started again. Flushes will get 168 * delayed if they're blocked by some outstanding asynchronous rendering. 169 * 170 * Can be called without any locks held. 171 */ 172 void intel_frontbuffer_flush(struct drm_device *dev, 173 unsigned frontbuffer_bits) 174 { 175 struct drm_i915_private *dev_priv = dev->dev_private; 176 177 /* Delay flushing when rings are still busy.*/ 178 mutex_lock(&dev_priv->fb_tracking.lock); 179 frontbuffer_bits &= ~dev_priv->fb_tracking.busy_bits; 180 mutex_unlock(&dev_priv->fb_tracking.lock); 181 182 intel_mark_fb_busy(dev, frontbuffer_bits, NULL); 183 184 intel_edp_drrs_flush(dev, frontbuffer_bits); 185 intel_psr_flush(dev, frontbuffer_bits); 186 intel_fbc_flush(dev_priv, frontbuffer_bits); 187 } 188 189 /** 190 * intel_fb_obj_flush - flush frontbuffer object 191 * @obj: GEM object to flush 192 * @retire: set when retiring asynchronous rendering 193 * 194 * This function gets called every time rendering on the given object has 195 * completed and frontbuffer caching can be started again. If @retire is true 196 * then any delayed flushes will be unblocked. 197 */ 198 void intel_fb_obj_flush(struct drm_i915_gem_object *obj, 199 bool retire) 200 { 201 struct drm_device *dev = obj->base.dev; 202 struct drm_i915_private *dev_priv = dev->dev_private; 203 unsigned frontbuffer_bits; 204 205 WARN_ON(!mutex_is_locked(&dev->struct_mutex)); 206 207 if (!obj->frontbuffer_bits) 208 return; 209 210 frontbuffer_bits = obj->frontbuffer_bits; 211 212 if (retire) { 213 mutex_lock(&dev_priv->fb_tracking.lock); 214 /* Filter out new bits since rendering started. */ 215 frontbuffer_bits &= dev_priv->fb_tracking.busy_bits; 216 217 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits; 218 mutex_unlock(&dev_priv->fb_tracking.lock); 219 } 220 221 intel_frontbuffer_flush(dev, frontbuffer_bits); 222 } 223 224 /** 225 * intel_frontbuffer_flip_prepare - prepare asynchronous frontbuffer flip 226 * @dev: DRM device 227 * @frontbuffer_bits: frontbuffer plane tracking bits 228 * 229 * This function gets called after scheduling a flip on @obj. The actual 230 * frontbuffer flushing will be delayed until completion is signalled with 231 * intel_frontbuffer_flip_complete. If an invalidate happens in between this 232 * flush will be cancelled. 233 * 234 * Can be called without any locks held. 235 */ 236 void intel_frontbuffer_flip_prepare(struct drm_device *dev, 237 unsigned frontbuffer_bits) 238 { 239 struct drm_i915_private *dev_priv = dev->dev_private; 240 241 mutex_lock(&dev_priv->fb_tracking.lock); 242 dev_priv->fb_tracking.flip_bits |= frontbuffer_bits; 243 /* Remove stale busy bits due to the old buffer. */ 244 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits; 245 mutex_unlock(&dev_priv->fb_tracking.lock); 246 247 intel_psr_single_frame_update(dev); 248 } 249 250 /** 251 * intel_frontbuffer_flip_complete - complete asynchronous frontbuffer flip 252 * @dev: DRM device 253 * @frontbuffer_bits: frontbuffer plane tracking bits 254 * 255 * This function gets called after the flip has been latched and will complete 256 * on the next vblank. It will execute the flush if it hasn't been cancelled yet. 257 * 258 * Can be called without any locks held. 259 */ 260 void intel_frontbuffer_flip_complete(struct drm_device *dev, 261 unsigned frontbuffer_bits) 262 { 263 struct drm_i915_private *dev_priv = dev->dev_private; 264 265 mutex_lock(&dev_priv->fb_tracking.lock); 266 /* Mask any cancelled flips. */ 267 frontbuffer_bits &= dev_priv->fb_tracking.flip_bits; 268 dev_priv->fb_tracking.flip_bits &= ~frontbuffer_bits; 269 mutex_unlock(&dev_priv->fb_tracking.lock); 270 271 intel_frontbuffer_flush(dev, frontbuffer_bits); 272 } 273