drivers/gpu/drm/v3d/v3d_sched.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /* Copyright (C) 2018 Broadcom */
   3
   4 /**
   5  * DOC: Broadcom V3D scheduling
   6  *
   7  * The shared DRM GPU scheduler is used to coordinate submitting jobs
   8  * to the hardware.  Each DRM fd (roughly a client process) gets its
   9  * own scheduler entity, which will process jobs in order.  The GPU
  10  * scheduler will round-robin between clients to submit the next job.
  11  *
  12  * For simplicity, and in order to keep latency low for interactive
  13  * jobs when bulk background jobs are queued up, we submit a new job
  14  * to the HW only when it has completed the last one, instead of
  15  * filling up the CT[01]Q FIFOs with jobs.  Similarly, we use
  16  * v3d_job_dependency() to manage the dependency between bin and
  17  * render, instead of having the clients submit jobs using the HW's
  18  * semaphores to interlock between them.
  19  */
  20
  21 #include <linux/kthread.h>
  22
  23 #include "v3d_drv.h"
  24 #include "v3d_regs.h"
  25 #include "v3d_trace.h"
  26
  27 static struct v3d_job *
  28 to_v3d_job(struct drm_sched_job *sched_job)
  29 {
  30         return container_of(sched_job, struct v3d_job, base);
  31 }
  32
  33 static struct v3d_tfu_job *
  34 to_tfu_job(struct drm_sched_job *sched_job)
  35 {
  36         return container_of(sched_job, struct v3d_tfu_job, base);
  37 }
  38
  39 static void
  40 v3d_job_free(struct drm_sched_job *sched_job)
  41 {
  42         struct v3d_job *job = to_v3d_job(sched_job);
  43
  44         drm_sched_job_cleanup(sched_job);
  45
  46         v3d_exec_put(job->exec);
  47 }
  48
  49 static void
  50 v3d_tfu_job_free(struct drm_sched_job *sched_job)
  51 {
  52         struct v3d_tfu_job *job = to_tfu_job(sched_job);
  53
  54         drm_sched_job_cleanup(sched_job);
  55
  56         v3d_tfu_job_put(job);
  57 }
  58
  59 /**
  60  * Returns the fences that the bin or render job depends on, one by one.
  61  * v3d_job_run() won't be called until all of them have been signaled.
  62  */
  63 static struct dma_fence *
  64 v3d_job_dependency(struct drm_sched_job *sched_job,
  65                    struct drm_sched_entity *s_entity)
  66 {
  67         struct v3d_job *job = to_v3d_job(sched_job);
  68         struct v3d_exec_info *exec = job->exec;
  69         enum v3d_queue q = job == &exec->bin ? V3D_BIN : V3D_RENDER;
  70         struct dma_fence *fence;
  71
  72         fence = job->in_fence;
  73         if (fence) {
  74                 job->in_fence = NULL;
  75                 return fence;
  76         }
  77
  78         if (q == V3D_RENDER) {
  79                 /* If we had a bin job, the render job definitely depends on
  80                  * it. We first have to wait for bin to be scheduled, so that
  81                  * its done_fence is created.
  82                  */
  83                 fence = exec->bin_done_fence;
  84                 if (fence) {
  85                         exec->bin_done_fence = NULL;
  86                         return fence;
  87                 }
  88         }
  89
  90         /* XXX: Wait on a fence for switching the GMP if necessary,
  91          * and then do so.
  92          */
  93
  94         return fence;
  95 }
  96
  97 /**
  98  * Returns the fences that the TFU job depends on, one by one.
  99  * v3d_tfu_job_run() won't be called until all of them have been
 100  * signaled.
 101  */
 102 static struct dma_fence *
 103 v3d_tfu_job_dependency(struct drm_sched_job *sched_job,
 104                        struct drm_sched_entity *s_entity)
 105 {
 106         struct v3d_tfu_job *job = to_tfu_job(sched_job);
 107         struct dma_fence *fence;
 108
 109         fence = job->in_fence;
 110         if (fence) {
 111                 job->in_fence = NULL;
 112                 return fence;
 113         }
 114
 115         return NULL;
 116 }
 117
 118 static struct dma_fence *v3d_job_run(struct drm_sched_job *sched_job)
 119 {
 120         struct v3d_job *job = to_v3d_job(sched_job);
 121         struct v3d_exec_info *exec = job->exec;
 122         enum v3d_queue q = job == &exec->bin ? V3D_BIN : V3D_RENDER;
 123         struct v3d_dev *v3d = exec->v3d;
 124         struct drm_device *dev = &v3d->drm;
 125         struct dma_fence *fence;
 126         unsigned long irqflags;
 127
 128         if (unlikely(job->base.s_fence->finished.error))
 129                 return NULL;
 130
 131         /* Lock required around bin_job update vs
 132          * v3d_overflow_mem_work().
 133          */
 134         spin_lock_irqsave(&v3d->job_lock, irqflags);
 135         if (q == V3D_BIN) {
 136                 v3d->bin_job = job->exec;
 137
 138                 /* Clear out the overflow allocation, so we don't
 139                  * reuse the overflow attached to a previous job.
 140                  */
 141                 V3D_CORE_WRITE(0, V3D_PTB_BPOS, 0);
 142         } else {
 143                 v3d->render_job = job->exec;
 144         }
 145         spin_unlock_irqrestore(&v3d->job_lock, irqflags);
 146
 147         /* Can we avoid this flush when q==RENDER?  We need to be
 148          * careful of scheduling, though -- imagine job0 rendering to
 149          * texture and job1 reading, and them being executed as bin0,
 150          * bin1, render0, render1, so that render1's flush at bin time
 151          * wasn't enough.
 152          */
 153         v3d_invalidate_caches(v3d);
 154
 155         fence = v3d_fence_create(v3d, q);
 156         if (IS_ERR(fence))
 157                 return NULL;
 158
 159         if (job->done_fence)
 160                 dma_fence_put(job->done_fence);
 161         job->done_fence = dma_fence_get(fence);
 162
 163         trace_v3d_submit_cl(dev, q == V3D_RENDER, to_v3d_fence(fence)->seqno,
 164                             job->start, job->end);
 165
 166         if (q == V3D_BIN) {
 167                 if (exec->qma) {
 168                         V3D_CORE_WRITE(0, V3D_CLE_CT0QMA, exec->qma);
 169                         V3D_CORE_WRITE(0, V3D_CLE_CT0QMS, exec->qms);
 170                 }
 171                 if (exec->qts) {
 172                         V3D_CORE_WRITE(0, V3D_CLE_CT0QTS,
 173                                        V3D_CLE_CT0QTS_ENABLE |
 174                                        exec->qts);
 175                 }
 176         } else {
 177                 /* XXX: Set the QCFG */
 178         }
 179
 180         /* Set the current and end address of the control list.
 181          * Writing the end register is what starts the job.
 182          */
 183         V3D_CORE_WRITE(0, V3D_CLE_CTNQBA(q), job->start);
 184         V3D_CORE_WRITE(0, V3D_CLE_CTNQEA(q), job->end);
 185
 186         return fence;
 187 }
 188
 189 static struct dma_fence *
 190 v3d_tfu_job_run(struct drm_sched_job *sched_job)
 191 {
 192         struct v3d_tfu_job *job = to_tfu_job(sched_job);
 193         struct v3d_dev *v3d = job->v3d;
 194         struct drm_device *dev = &v3d->drm;
 195         struct dma_fence *fence;
 196
 197         fence = v3d_fence_create(v3d, V3D_TFU);
 198         if (IS_ERR(fence))
 199                 return NULL;
 200
 201         v3d->tfu_job = job;
 202         if (job->done_fence)
 203                 dma_fence_put(job->done_fence);
 204         job->done_fence = dma_fence_get(fence);
 205
 206         trace_v3d_submit_tfu(dev, to_v3d_fence(fence)->seqno);
 207
 208         V3D_WRITE(V3D_TFU_IIA, job->args.iia);
 209         V3D_WRITE(V3D_TFU_IIS, job->args.iis);
 210         V3D_WRITE(V3D_TFU_ICA, job->args.ica);
 211         V3D_WRITE(V3D_TFU_IUA, job->args.iua);
 212         V3D_WRITE(V3D_TFU_IOA, job->args.ioa);
 213         V3D_WRITE(V3D_TFU_IOS, job->args.ios);
 214         V3D_WRITE(V3D_TFU_COEF0, job->args.coef[0]);
 215         if (job->args.coef[0] & V3D_TFU_COEF0_USECOEF) {
 216                 V3D_WRITE(V3D_TFU_COEF1, job->args.coef[1]);
 217                 V3D_WRITE(V3D_TFU_COEF2, job->args.coef[2]);
 218                 V3D_WRITE(V3D_TFU_COEF3, job->args.coef[3]);
 219         }
 220         /* ICFG kicks off the job. */
 221         V3D_WRITE(V3D_TFU_ICFG, job->args.icfg | V3D_TFU_ICFG_IOC);
 222
 223         return fence;
 224 }
 225
 226 static void
 227 v3d_gpu_reset_for_timeout(struct v3d_dev *v3d, struct drm_sched_job *sched_job)
 228 {
 229         enum v3d_queue q;
 230
 231         mutex_lock(&v3d->reset_lock);
 232
 233         /* block scheduler */
 234         for (q = 0; q < V3D_MAX_QUEUES; q++) {
 235                 struct drm_gpu_scheduler *sched = &v3d->queue[q].sched;
 236
 237                 kthread_park(sched->thread);
 238                 drm_sched_hw_job_reset(sched, (sched_job->sched == sched ?
 239                                                sched_job : NULL));
 240         }
 241
 242         /* get the GPU back into the init state */
 243         v3d_reset(v3d);
 244
 245         /* Unblock schedulers and restart their jobs. */
 246         for (q = 0; q < V3D_MAX_QUEUES; q++) {
 247                 drm_sched_job_recovery(&v3d->queue[q].sched);
 248                 kthread_unpark(v3d->queue[q].sched.thread);
 249         }
 250
 251         mutex_unlock(&v3d->reset_lock);
 252 }
 253
 254 static void
 255 v3d_job_timedout(struct drm_sched_job *sched_job)
 256 {
 257         struct v3d_job *job = to_v3d_job(sched_job);
 258         struct v3d_exec_info *exec = job->exec;
 259         struct v3d_dev *v3d = exec->v3d;
 260         enum v3d_queue job_q = job == &exec->bin ? V3D_BIN : V3D_RENDER;
 261         u32 ctca = V3D_CORE_READ(0, V3D_CLE_CTNCA(job_q));
 262         u32 ctra = V3D_CORE_READ(0, V3D_CLE_CTNRA(job_q));
 263
 264         /* If the current address or return address have changed, then
 265          * the GPU has probably made progress and we should delay the
 266          * reset.  This could fail if the GPU got in an infinite loop
 267          * in the CL, but that is pretty unlikely outside of an i-g-t
 268          * testcase.
 269          */
 270         if (job->timedout_ctca != ctca || job->timedout_ctra != ctra) {
 271                 job->timedout_ctca = ctca;
 272                 job->timedout_ctra = ctra;
 273                 return;
 274         }
 275
 276         v3d_gpu_reset_for_timeout(v3d, sched_job);
 277 }
 278
 279 static void
 280 v3d_tfu_job_timedout(struct drm_sched_job *sched_job)
 281 {
 282         struct v3d_tfu_job *job = to_tfu_job(sched_job);
 283
 284         v3d_gpu_reset_for_timeout(job->v3d, sched_job);
 285 }
 286
 287 static const struct drm_sched_backend_ops v3d_sched_ops = {
 288         .dependency = v3d_job_dependency,
 289         .run_job = v3d_job_run,
 290         .timedout_job = v3d_job_timedout,
 291         .free_job = v3d_job_free
 292 };
 293
 294 static const struct drm_sched_backend_ops v3d_tfu_sched_ops = {
 295         .dependency = v3d_tfu_job_dependency,
 296         .run_job = v3d_tfu_job_run,
 297         .timedout_job = v3d_tfu_job_timedout,
 298         .free_job = v3d_tfu_job_free
 299 };
 300
 301 int
 302 v3d_sched_init(struct v3d_dev *v3d)
 303 {
 304         int hw_jobs_limit = 1;
 305         int job_hang_limit = 0;
 306         int hang_limit_ms = 500;
 307         int ret;
 308
 309         ret = drm_sched_init(&v3d->queue[V3D_BIN].sched,
 310                              &v3d_sched_ops,
 311                              hw_jobs_limit, job_hang_limit,
 312                              msecs_to_jiffies(hang_limit_ms),
 313                              "v3d_bin");
 314         if (ret) {
 315                 dev_err(v3d->dev, "Failed to create bin scheduler: %d.", ret);
 316                 return ret;
 317         }
 318
 319         ret = drm_sched_init(&v3d->queue[V3D_RENDER].sched,
 320                              &v3d_sched_ops,
 321                              hw_jobs_limit, job_hang_limit,
 322                              msecs_to_jiffies(hang_limit_ms),
 323                              "v3d_render");
 324         if (ret) {
 325                 dev_err(v3d->dev, "Failed to create render scheduler: %d.",
 326                         ret);
 327                 drm_sched_fini(&v3d->queue[V3D_BIN].sched);
 328                 return ret;
 329         }
 330
 331         ret = drm_sched_init(&v3d->queue[V3D_TFU].sched,
 332                              &v3d_tfu_sched_ops,
 333                              hw_jobs_limit, job_hang_limit,
 334                              msecs_to_jiffies(hang_limit_ms),
 335                              "v3d_tfu");
 336         if (ret) {
 337                 dev_err(v3d->dev, "Failed to create TFU scheduler: %d.",
 338                         ret);
 339                 drm_sched_fini(&v3d->queue[V3D_RENDER].sched);
 340                 drm_sched_fini(&v3d->queue[V3D_BIN].sched);
 341                 return ret;
 342         }
 343
 344         return 0;
 345 }
 346
 347 void
 348 v3d_sched_fini(struct v3d_dev *v3d)
 349 {
 350         enum v3d_queue q;
 351
 352         for (q = 0; q < V3D_MAX_QUEUES; q++)
 353                 drm_sched_fini(&v3d->queue[q].sched);
 354 }