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 int ret; 144 145 /* We need target support to do devfreq */ 146 if (!gpu->funcs->gpu_busy) 147 return; 148 149 /* 150 * Setup default values for simple_ondemand governor tuning. We 151 * want to throttle up at 50% load for the double-buffer case, 152 * where due to stalling waiting for vblank we could get stuck 153 * at (for ex) 30fps at 50% utilization. 154 */ 155 priv->gpu_devfreq_config.upthreshold = 50; 156 priv->gpu_devfreq_config.downdifferential = 10; 157 158 mutex_init(&df->lock); 159 160 ret = dev_pm_qos_add_request(&gpu->pdev->dev, &df->boost_freq, 161 DEV_PM_QOS_MIN_FREQUENCY, 0); 162 if (ret < 0) { 163 DRM_DEV_ERROR(&gpu->pdev->dev, "Couldn't initialize QoS\n"); 164 return; 165 } 166 167 msm_devfreq_profile.initial_freq = gpu->fast_rate; 168 169 /* 170 * Don't set the freq_table or max_state and let devfreq build the table 171 * from OPP 172 * After a deferred probe, these may have be left to non-zero values, 173 * so set them back to zero before creating the devfreq device 174 */ 175 msm_devfreq_profile.freq_table = NULL; 176 msm_devfreq_profile.max_state = 0; 177 178 df->devfreq = devm_devfreq_add_device(&gpu->pdev->dev, 179 &msm_devfreq_profile, DEVFREQ_GOV_SIMPLE_ONDEMAND, 180 &priv->gpu_devfreq_config); 181 182 if (IS_ERR(df->devfreq)) { 183 DRM_DEV_ERROR(&gpu->pdev->dev, "Couldn't initialize GPU devfreq\n"); 184 dev_pm_qos_remove_request(&df->boost_freq); 185 df->devfreq = NULL; 186 return; 187 } 188 189 devfreq_suspend_device(df->devfreq); 190 191 gpu->cooling = of_devfreq_cooling_register(gpu->pdev->dev.of_node, df->devfreq); 192 if (IS_ERR(gpu->cooling)) { 193 DRM_DEV_ERROR(&gpu->pdev->dev, 194 "Couldn't register GPU cooling device\n"); 195 gpu->cooling = NULL; 196 } 197 198 msm_hrtimer_work_init(&df->boost_work, gpu->worker, msm_devfreq_boost_work, 199 CLOCK_MONOTONIC, HRTIMER_MODE_REL); 200 msm_hrtimer_work_init(&df->idle_work, gpu->worker, msm_devfreq_idle_work, 201 CLOCK_MONOTONIC, HRTIMER_MODE_REL); 202 } 203 204 static void cancel_idle_work(struct msm_gpu_devfreq *df) 205 { 206 hrtimer_cancel(&df->idle_work.timer); 207 kthread_cancel_work_sync(&df->idle_work.work); 208 } 209 210 static void cancel_boost_work(struct msm_gpu_devfreq *df) 211 { 212 hrtimer_cancel(&df->boost_work.timer); 213 kthread_cancel_work_sync(&df->boost_work.work); 214 } 215 216 void msm_devfreq_cleanup(struct msm_gpu *gpu) 217 { 218 struct msm_gpu_devfreq *df = &gpu->devfreq; 219 220 if (!has_devfreq(gpu)) 221 return; 222 223 devfreq_cooling_unregister(gpu->cooling); 224 dev_pm_qos_remove_request(&df->boost_freq); 225 } 226 227 void msm_devfreq_resume(struct msm_gpu *gpu) 228 { 229 struct msm_gpu_devfreq *df = &gpu->devfreq; 230 unsigned long sample_rate; 231 232 if (!has_devfreq(gpu)) 233 return; 234 235 mutex_lock(&df->lock); 236 df->busy_cycles = gpu->funcs->gpu_busy(gpu, &sample_rate); 237 df->time = ktime_get(); 238 df->suspended = false; 239 mutex_unlock(&df->lock); 240 241 devfreq_resume_device(df->devfreq); 242 } 243 244 void msm_devfreq_suspend(struct msm_gpu *gpu) 245 { 246 struct msm_gpu_devfreq *df = &gpu->devfreq; 247 248 if (!has_devfreq(gpu)) 249 return; 250 251 mutex_lock(&df->lock); 252 df->suspended = true; 253 mutex_unlock(&df->lock); 254 255 devfreq_suspend_device(df->devfreq); 256 257 cancel_idle_work(df); 258 cancel_boost_work(df); 259 } 260 261 static void msm_devfreq_boost_work(struct kthread_work *work) 262 { 263 struct msm_gpu_devfreq *df = container_of(work, 264 struct msm_gpu_devfreq, boost_work.work); 265 266 dev_pm_qos_update_request(&df->boost_freq, 0); 267 } 268 269 void msm_devfreq_boost(struct msm_gpu *gpu, unsigned factor) 270 { 271 struct msm_gpu_devfreq *df = &gpu->devfreq; 272 uint64_t freq; 273 274 if (!has_devfreq(gpu)) 275 return; 276 277 freq = get_freq(gpu); 278 freq *= factor; 279 280 /* 281 * A nice little trap is that PM QoS operates in terms of KHz, 282 * while devfreq operates in terms of Hz: 283 */ 284 do_div(freq, HZ_PER_KHZ); 285 286 dev_pm_qos_update_request(&df->boost_freq, freq); 287 288 msm_hrtimer_queue_work(&df->boost_work, 289 ms_to_ktime(msm_devfreq_profile.polling_ms), 290 HRTIMER_MODE_REL); 291 } 292 293 void msm_devfreq_active(struct msm_gpu *gpu) 294 { 295 struct msm_gpu_devfreq *df = &gpu->devfreq; 296 unsigned int idle_time; 297 unsigned long target_freq; 298 299 if (!has_devfreq(gpu)) 300 return; 301 302 /* 303 * Cancel any pending transition to idle frequency: 304 */ 305 cancel_idle_work(df); 306 307 /* 308 * Hold devfreq lock to synchronize with get_dev_status()/ 309 * target() callbacks 310 */ 311 mutex_lock(&df->devfreq->lock); 312 313 target_freq = df->idle_freq; 314 315 idle_time = ktime_to_ms(ktime_sub(ktime_get(), df->idle_time)); 316 317 df->idle_freq = 0; 318 319 /* 320 * We could have become active again before the idle work had a 321 * chance to run, in which case the df->idle_freq would have 322 * still been zero. In this case, no need to change freq. 323 */ 324 if (target_freq) 325 msm_devfreq_target(&gpu->pdev->dev, &target_freq, 0); 326 327 mutex_unlock(&df->devfreq->lock); 328 329 /* 330 * If we've been idle for a significant fraction of a polling 331 * interval, then we won't meet the threshold of busyness for 332 * the governor to ramp up the freq.. so give some boost 333 */ 334 if (idle_time > msm_devfreq_profile.polling_ms) { 335 msm_devfreq_boost(gpu, 2); 336 } 337 } 338 339 340 static void msm_devfreq_idle_work(struct kthread_work *work) 341 { 342 struct msm_gpu_devfreq *df = container_of(work, 343 struct msm_gpu_devfreq, idle_work.work); 344 struct msm_gpu *gpu = container_of(df, struct msm_gpu, devfreq); 345 struct msm_drm_private *priv = gpu->dev->dev_private; 346 unsigned long idle_freq, target_freq = 0; 347 348 /* 349 * Hold devfreq lock to synchronize with get_dev_status()/ 350 * target() callbacks 351 */ 352 mutex_lock(&df->devfreq->lock); 353 354 idle_freq = get_freq(gpu); 355 356 if (priv->gpu_clamp_to_idle) 357 msm_devfreq_target(&gpu->pdev->dev, &target_freq, 0); 358 359 df->idle_time = ktime_get(); 360 df->idle_freq = idle_freq; 361 362 mutex_unlock(&df->devfreq->lock); 363 } 364 365 void msm_devfreq_idle(struct msm_gpu *gpu) 366 { 367 struct msm_gpu_devfreq *df = &gpu->devfreq; 368 369 if (!has_devfreq(gpu)) 370 return; 371 372 msm_hrtimer_queue_work(&df->idle_work, ms_to_ktime(1), 373 HRTIMER_MODE_REL); 374 } 375