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 if (!i915.powersave) 114 return; 115 116 for_each_pipe(dev_priv, pipe) { 117 if (!(frontbuffer_bits & INTEL_FRONTBUFFER_ALL_MASK(pipe))) 118 continue; 119 120 intel_increase_pllclock(dev, pipe); 121 if (ring && intel_fbc_enabled(dev)) 122 ring->fbc_dirty = true; 123 } 124 } 125 126 /** 127 * intel_fb_obj_invalidate - invalidate frontbuffer object 128 * @obj: GEM object to invalidate 129 * @ring: set for asynchronous rendering 130 * 131 * This function gets called every time rendering on the given object starts and 132 * frontbuffer caching (fbc, low refresh rate for DRRS, panel self refresh) must 133 * be invalidated. If @ring is non-NULL any subsequent invalidation will be delayed 134 * until the rendering completes or a flip on this frontbuffer plane is 135 * scheduled. 136 */ 137 void intel_fb_obj_invalidate(struct drm_i915_gem_object *obj, 138 struct intel_engine_cs *ring) 139 { 140 struct drm_device *dev = obj->base.dev; 141 struct drm_i915_private *dev_priv = dev->dev_private; 142 143 WARN_ON(!mutex_is_locked(&dev->struct_mutex)); 144 145 if (!obj->frontbuffer_bits) 146 return; 147 148 if (ring) { 149 mutex_lock(&dev_priv->fb_tracking.lock); 150 dev_priv->fb_tracking.busy_bits 151 |= obj->frontbuffer_bits; 152 dev_priv->fb_tracking.flip_bits 153 &= ~obj->frontbuffer_bits; 154 mutex_unlock(&dev_priv->fb_tracking.lock); 155 } 156 157 intel_mark_fb_busy(dev, obj->frontbuffer_bits, ring); 158 159 intel_psr_invalidate(dev, obj->frontbuffer_bits); 160 intel_edp_drrs_invalidate(dev, obj->frontbuffer_bits); 161 } 162 163 /** 164 * intel_frontbuffer_flush - flush frontbuffer 165 * @dev: DRM device 166 * @frontbuffer_bits: frontbuffer plane tracking bits 167 * 168 * This function gets called every time rendering on the given planes has 169 * completed and frontbuffer caching can be started again. Flushes will get 170 * delayed if they're blocked by some outstanding asynchronous rendering. 171 * 172 * Can be called without any locks held. 173 */ 174 void intel_frontbuffer_flush(struct drm_device *dev, 175 unsigned frontbuffer_bits) 176 { 177 struct drm_i915_private *dev_priv = dev->dev_private; 178 179 /* Delay flushing when rings are still busy.*/ 180 mutex_lock(&dev_priv->fb_tracking.lock); 181 frontbuffer_bits &= ~dev_priv->fb_tracking.busy_bits; 182 mutex_unlock(&dev_priv->fb_tracking.lock); 183 184 intel_mark_fb_busy(dev, frontbuffer_bits, NULL); 185 186 intel_edp_drrs_flush(dev, frontbuffer_bits); 187 intel_psr_flush(dev, frontbuffer_bits); 188 189 /* 190 * FIXME: Unconditional fbc flushing here is a rather gross hack and 191 * needs to be reworked into a proper frontbuffer tracking scheme like 192 * psr employs. 193 */ 194 if (dev_priv->fbc.need_sw_cache_clean) { 195 dev_priv->fbc.need_sw_cache_clean = false; 196 bdw_fbc_sw_flush(dev, FBC_REND_CACHE_CLEAN); 197 } 198 } 199 200 /** 201 * intel_fb_obj_flush - flush frontbuffer object 202 * @obj: GEM object to flush 203 * @retire: set when retiring asynchronous rendering 204 * 205 * This function gets called every time rendering on the given object has 206 * completed and frontbuffer caching can be started again. If @retire is true 207 * then any delayed flushes will be unblocked. 208 */ 209 void intel_fb_obj_flush(struct drm_i915_gem_object *obj, 210 bool retire) 211 { 212 struct drm_device *dev = obj->base.dev; 213 struct drm_i915_private *dev_priv = dev->dev_private; 214 unsigned frontbuffer_bits; 215 216 WARN_ON(!mutex_is_locked(&dev->struct_mutex)); 217 218 if (!obj->frontbuffer_bits) 219 return; 220 221 frontbuffer_bits = obj->frontbuffer_bits; 222 223 if (retire) { 224 mutex_lock(&dev_priv->fb_tracking.lock); 225 /* Filter out new bits since rendering started. */ 226 frontbuffer_bits &= dev_priv->fb_tracking.busy_bits; 227 228 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits; 229 mutex_unlock(&dev_priv->fb_tracking.lock); 230 } 231 232 intel_frontbuffer_flush(dev, frontbuffer_bits); 233 } 234 235 /** 236 * intel_frontbuffer_flip_prepare - prepare asynchronous frontbuffer flip 237 * @dev: DRM device 238 * @frontbuffer_bits: frontbuffer plane tracking bits 239 * 240 * This function gets called after scheduling a flip on @obj. The actual 241 * frontbuffer flushing will be delayed until completion is signalled with 242 * intel_frontbuffer_flip_complete. If an invalidate happens in between this 243 * flush will be cancelled. 244 * 245 * Can be called without any locks held. 246 */ 247 void intel_frontbuffer_flip_prepare(struct drm_device *dev, 248 unsigned frontbuffer_bits) 249 { 250 struct drm_i915_private *dev_priv = dev->dev_private; 251 252 mutex_lock(&dev_priv->fb_tracking.lock); 253 dev_priv->fb_tracking.flip_bits |= frontbuffer_bits; 254 /* Remove stale busy bits due to the old buffer. */ 255 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits; 256 mutex_unlock(&dev_priv->fb_tracking.lock); 257 } 258 259 /** 260 * intel_frontbuffer_flip_complete - complete asynchronous frontbuffer flip 261 * @dev: DRM device 262 * @frontbuffer_bits: frontbuffer plane tracking bits 263 * 264 * This function gets called after the flip has been latched and will complete 265 * on the next vblank. It will execute the flush if it hasn't been cancelled yet. 266 * 267 * Can be called without any locks held. 268 */ 269 void intel_frontbuffer_flip_complete(struct drm_device *dev, 270 unsigned frontbuffer_bits) 271 { 272 struct drm_i915_private *dev_priv = dev->dev_private; 273 274 mutex_lock(&dev_priv->fb_tracking.lock); 275 /* Mask any cancelled flips. */ 276 frontbuffer_bits &= dev_priv->fb_tracking.flip_bits; 277 dev_priv->fb_tracking.flip_bits &= ~frontbuffer_bits; 278 mutex_unlock(&dev_priv->fb_tracking.lock); 279 280 intel_frontbuffer_flush(dev, frontbuffer_bits); 281 } 282