1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2013 Red Hat 4 * Author: Rob Clark <robdclark@gmail.com> 5 */ 6 7 #include "msm_gpu.h" 8 #include "msm_gpu_trace.h" 9 10 #include <linux/devfreq.h> 11 #include <linux/devfreq_cooling.h> 12 #include <linux/math64.h> 13 #include <linux/units.h> 14 15 /* 16 * Power Management: 17 */ 18 19 static int msm_devfreq_target(struct device *dev, unsigned long *freq, 20 u32 flags) 21 { 22 struct msm_gpu *gpu = dev_to_gpu(dev); 23 struct msm_gpu_devfreq *df = &gpu->devfreq; 24 struct dev_pm_opp *opp; 25 26 /* 27 * Note that devfreq_recommended_opp() can modify the freq 28 * to something that actually is in the opp table: 29 */ 30 opp = devfreq_recommended_opp(dev, freq, flags); 31 if (IS_ERR(opp)) 32 return PTR_ERR(opp); 33 34 trace_msm_gpu_freq_change(dev_pm_opp_get_freq(opp)); 35 36 /* 37 * If the GPU is idle, devfreq is not aware, so just stash 38 * the new target freq (to use when we return to active) 39 */ 40 if (df->idle_freq) { 41 df->idle_freq = *freq; 42 dev_pm_opp_put(opp); 43 return 0; 44 } 45 46 if (gpu->funcs->gpu_set_freq) { 47 mutex_lock(&df->lock); 48 gpu->funcs->gpu_set_freq(gpu, opp, df->suspended); 49 mutex_unlock(&df->lock); 50 } else { 51 dev_pm_opp_set_rate(dev, *freq); 52 } 53 54 dev_pm_opp_put(opp); 55 56 return 0; 57 } 58 59 static unsigned long get_freq(struct msm_gpu *gpu) 60 { 61 struct msm_gpu_devfreq *df = &gpu->devfreq; 62 63 /* 64 * If the GPU is idle, use the shadow/saved freq to avoid 65 * confusing devfreq (which is unaware that we are switching 66 * to lowest freq until the device is active again) 67 */ 68 if (df->idle_freq) 69 return df->idle_freq; 70 71 if (gpu->funcs->gpu_get_freq) 72 return gpu->funcs->gpu_get_freq(gpu); 73 74 return clk_get_rate(gpu->core_clk); 75 } 76 77 static int msm_devfreq_get_dev_status(struct device *dev, 78 struct devfreq_dev_status *status) 79 { 80 struct msm_gpu *gpu = dev_to_gpu(dev); 81 struct msm_gpu_devfreq *df = &gpu->devfreq; 82 u64 busy_cycles, busy_time; 83 unsigned long sample_rate; 84 ktime_t time; 85 86 mutex_lock(&df->lock); 87 88 status->current_frequency = get_freq(gpu); 89 time = ktime_get(); 90 status->total_time = ktime_us_delta(time, df->time); 91 df->time = time; 92 93 if (df->suspended) { 94 mutex_unlock(&df->lock); 95 status->busy_time = 0; 96 return 0; 97 } 98 99 busy_cycles = gpu->funcs->gpu_busy(gpu, &sample_rate); 100 busy_time = busy_cycles - df->busy_cycles; 101 df->busy_cycles = busy_cycles; 102 103 mutex_unlock(&df->lock); 104 105 busy_time *= USEC_PER_SEC; 106 busy_time = div64_ul(busy_time, sample_rate); 107 if (WARN_ON(busy_time > ~0LU)) 108 busy_time = ~0LU; 109 110 status->busy_time = busy_time; 111 112 return 0; 113 } 114 115 static int msm_devfreq_get_cur_freq(struct device *dev, unsigned long *freq) 116 { 117 *freq = get_freq(dev_to_gpu(dev)); 118 119 return 0; 120 } 121 122 static struct devfreq_dev_profile msm_devfreq_profile = { 123 .timer = DEVFREQ_TIMER_DELAYED, 124 .polling_ms = 50, 125 .target = msm_devfreq_target, 126 .get_dev_status = msm_devfreq_get_dev_status, 127 .get_cur_freq = msm_devfreq_get_cur_freq, 128 }; 129 130 static void msm_devfreq_boost_work(struct kthread_work *work); 131 static void msm_devfreq_idle_work(struct kthread_work *work); 132 133 static bool has_devfreq(struct msm_gpu *gpu) 134 { 135 struct msm_gpu_devfreq *df = &gpu->devfreq; 136 return !!df->devfreq; 137 } 138 139 void msm_devfreq_init(struct msm_gpu *gpu) 140 { 141 struct msm_gpu_devfreq *df = &gpu->devfreq; 142 struct msm_drm_private *priv = gpu->dev->dev_private; 143 144 /* We need target support to do devfreq */ 145 if (!gpu->funcs->gpu_busy) 146 return; 147 148 /* 149 * Setup default values for simple_ondemand governor tuning. We 150 * want to throttle up at 50% load for the double-buffer case, 151 * where due to stalling waiting for vblank we could get stuck 152 * at (for ex) 30fps at 50% utilization. 153 */ 154 priv->gpu_devfreq_config.upthreshold = 50; 155 priv->gpu_devfreq_config.downdifferential = 10; 156 157 mutex_init(&df->lock); 158 159 dev_pm_qos_add_request(&gpu->pdev->dev, &df->boost_freq, 160 DEV_PM_QOS_MIN_FREQUENCY, 0); 161 162 msm_devfreq_profile.initial_freq = gpu->fast_rate; 163 164 /* 165 * Don't set the freq_table or max_state and let devfreq build the table 166 * from OPP 167 * After a deferred probe, these may have be left to non-zero values, 168 * so set them back to zero before creating the devfreq device 169 */ 170 msm_devfreq_profile.freq_table = NULL; 171 msm_devfreq_profile.max_state = 0; 172 173 df->devfreq = devm_devfreq_add_device(&gpu->pdev->dev, 174 &msm_devfreq_profile, DEVFREQ_GOV_SIMPLE_ONDEMAND, 175 &priv->gpu_devfreq_config); 176 177 if (IS_ERR(df->devfreq)) { 178 DRM_DEV_ERROR(&gpu->pdev->dev, "Couldn't initialize GPU devfreq\n"); 179 dev_pm_qos_remove_request(&df->boost_freq); 180 df->devfreq = NULL; 181 return; 182 } 183 184 devfreq_suspend_device(df->devfreq); 185 186 gpu->cooling = of_devfreq_cooling_register(gpu->pdev->dev.of_node, df->devfreq); 187 if (IS_ERR(gpu->cooling)) { 188 DRM_DEV_ERROR(&gpu->pdev->dev, 189 "Couldn't register GPU cooling device\n"); 190 gpu->cooling = NULL; 191 } 192 193 msm_hrtimer_work_init(&df->boost_work, gpu->worker, msm_devfreq_boost_work, 194 CLOCK_MONOTONIC, HRTIMER_MODE_REL); 195 msm_hrtimer_work_init(&df->idle_work, gpu->worker, msm_devfreq_idle_work, 196 CLOCK_MONOTONIC, HRTIMER_MODE_REL); 197 } 198 199 static void cancel_idle_work(struct msm_gpu_devfreq *df) 200 { 201 hrtimer_cancel(&df->idle_work.timer); 202 kthread_cancel_work_sync(&df->idle_work.work); 203 } 204 205 static void cancel_boost_work(struct msm_gpu_devfreq *df) 206 { 207 hrtimer_cancel(&df->boost_work.timer); 208 kthread_cancel_work_sync(&df->boost_work.work); 209 } 210 211 void msm_devfreq_cleanup(struct msm_gpu *gpu) 212 { 213 struct msm_gpu_devfreq *df = &gpu->devfreq; 214 215 if (!has_devfreq(gpu)) 216 return; 217 218 devfreq_cooling_unregister(gpu->cooling); 219 dev_pm_qos_remove_request(&df->boost_freq); 220 } 221 222 void msm_devfreq_resume(struct msm_gpu *gpu) 223 { 224 struct msm_gpu_devfreq *df = &gpu->devfreq; 225 unsigned long sample_rate; 226 227 if (!has_devfreq(gpu)) 228 return; 229 230 mutex_lock(&df->lock); 231 df->busy_cycles = gpu->funcs->gpu_busy(gpu, &sample_rate); 232 df->time = ktime_get(); 233 df->suspended = false; 234 mutex_unlock(&df->lock); 235 236 devfreq_resume_device(df->devfreq); 237 } 238 239 void msm_devfreq_suspend(struct msm_gpu *gpu) 240 { 241 struct msm_gpu_devfreq *df = &gpu->devfreq; 242 243 if (!has_devfreq(gpu)) 244 return; 245 246 mutex_lock(&df->lock); 247 df->suspended = true; 248 mutex_unlock(&df->lock); 249 250 devfreq_suspend_device(df->devfreq); 251 252 cancel_idle_work(df); 253 cancel_boost_work(df); 254 } 255 256 static void msm_devfreq_boost_work(struct kthread_work *work) 257 { 258 struct msm_gpu_devfreq *df = container_of(work, 259 struct msm_gpu_devfreq, boost_work.work); 260 261 dev_pm_qos_update_request(&df->boost_freq, 0); 262 } 263 264 void msm_devfreq_boost(struct msm_gpu *gpu, unsigned factor) 265 { 266 struct msm_gpu_devfreq *df = &gpu->devfreq; 267 uint64_t freq; 268 269 if (!has_devfreq(gpu)) 270 return; 271 272 freq = get_freq(gpu); 273 freq *= factor; 274 275 /* 276 * A nice little trap is that PM QoS operates in terms of KHz, 277 * while devfreq operates in terms of Hz: 278 */ 279 do_div(freq, HZ_PER_KHZ); 280 281 dev_pm_qos_update_request(&df->boost_freq, freq); 282 283 msm_hrtimer_queue_work(&df->boost_work, 284 ms_to_ktime(msm_devfreq_profile.polling_ms), 285 HRTIMER_MODE_REL); 286 } 287 288 void msm_devfreq_active(struct msm_gpu *gpu) 289 { 290 struct msm_gpu_devfreq *df = &gpu->devfreq; 291 unsigned int idle_time; 292 unsigned long target_freq; 293 294 if (!has_devfreq(gpu)) 295 return; 296 297 /* 298 * Cancel any pending transition to idle frequency: 299 */ 300 cancel_idle_work(df); 301 302 /* 303 * Hold devfreq lock to synchronize with get_dev_status()/ 304 * target() callbacks 305 */ 306 mutex_lock(&df->devfreq->lock); 307 308 target_freq = df->idle_freq; 309 310 idle_time = ktime_to_ms(ktime_sub(ktime_get(), df->idle_time)); 311 312 df->idle_freq = 0; 313 314 /* 315 * We could have become active again before the idle work had a 316 * chance to run, in which case the df->idle_freq would have 317 * still been zero. In this case, no need to change freq. 318 */ 319 if (target_freq) 320 msm_devfreq_target(&gpu->pdev->dev, &target_freq, 0); 321 322 mutex_unlock(&df->devfreq->lock); 323 324 /* 325 * If we've been idle for a significant fraction of a polling 326 * interval, then we won't meet the threshold of busyness for 327 * the governor to ramp up the freq.. so give some boost 328 */ 329 if (idle_time > msm_devfreq_profile.polling_ms) { 330 msm_devfreq_boost(gpu, 2); 331 } 332 } 333 334 335 static void msm_devfreq_idle_work(struct kthread_work *work) 336 { 337 struct msm_gpu_devfreq *df = container_of(work, 338 struct msm_gpu_devfreq, idle_work.work); 339 struct msm_gpu *gpu = container_of(df, struct msm_gpu, devfreq); 340 struct msm_drm_private *priv = gpu->dev->dev_private; 341 unsigned long idle_freq, target_freq = 0; 342 343 /* 344 * Hold devfreq lock to synchronize with get_dev_status()/ 345 * target() callbacks 346 */ 347 mutex_lock(&df->devfreq->lock); 348 349 idle_freq = get_freq(gpu); 350 351 if (priv->gpu_clamp_to_idle) 352 msm_devfreq_target(&gpu->pdev->dev, &target_freq, 0); 353 354 df->idle_time = ktime_get(); 355 df->idle_freq = idle_freq; 356 357 mutex_unlock(&df->devfreq->lock); 358 } 359 360 void msm_devfreq_idle(struct msm_gpu *gpu) 361 { 362 struct msm_gpu_devfreq *df = &gpu->devfreq; 363 364 if (!has_devfreq(gpu)) 365 return; 366 367 msm_hrtimer_queue_work(&df->idle_work, ms_to_ktime(1), 368 HRTIMER_MODE_REL); 369 } 370