drivers/gpu/host1x/syncpt.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Tegra host1x Syncpoints
   4  *
   5  * Copyright (c) 2010-2015, NVIDIA Corporation.
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/device.h>
  10 #include <linux/slab.h>
  11
  12 #include <trace/events/host1x.h>
  13
  14 #include "syncpt.h"
  15 #include "dev.h"
  16 #include "intr.h"
  17 #include "debug.h"
  18
  19 #define SYNCPT_CHECK_PERIOD (2 * HZ)
  20 #define MAX_STUCK_CHECK_COUNT 15
  21
  22 static struct host1x_syncpt_base *
  23 host1x_syncpt_base_request(struct host1x *host)
  24 {
  25         struct host1x_syncpt_base *bases = host->bases;
  26         unsigned int i;
  27
  28         for (i = 0; i < host->info->nb_bases; i++)
  29                 if (!bases[i].requested)
  30                         break;
  31
  32         if (i >= host->info->nb_bases)
  33                 return NULL;
  34
  35         bases[i].requested = true;
  36         return &bases[i];
  37 }
  38
  39 static void host1x_syncpt_base_free(struct host1x_syncpt_base *base)
  40 {
  41         if (base)
  42                 base->requested = false;
  43 }
  44
  45 /**
  46  * host1x_syncpt_alloc() - allocate a syncpoint
  47  * @host: host1x device data
  48  * @flags: bitfield of HOST1X_SYNCPT_* flags
  49  * @name: name for the syncpoint for use in debug prints
  50  *
  51  * Allocates a hardware syncpoint for the caller's use. The caller then has
  52  * the sole authority to mutate the syncpoint's value until it is freed again.
  53  *
  54  * If no free syncpoints are available, or a NULL name was specified, returns
  55  * NULL.
  56  */
  57 struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host,
  58                                           unsigned long flags,
  59                                           const char *name)
  60 {
  61         struct host1x_syncpt *sp = host->syncpt;
  62         char *full_name;
  63         unsigned int i;
  64
  65         if (!name)
  66                 return NULL;
  67
  68         mutex_lock(&host->syncpt_mutex);
  69
  70         for (i = 0; i < host->info->nb_pts && kref_read(&sp->ref); i++, sp++)
  71                 ;
  72
  73         if (i >= host->info->nb_pts)
  74                 goto unlock;
  75
  76         if (flags & HOST1X_SYNCPT_HAS_BASE) {
  77                 sp->base = host1x_syncpt_base_request(host);
  78                 if (!sp->base)
  79                         goto unlock;
  80         }
  81
  82         full_name = kasprintf(GFP_KERNEL, "%u-%s", sp->id, name);
  83         if (!full_name)
  84                 goto free_base;
  85
  86         sp->name = full_name;
  87
  88         if (flags & HOST1X_SYNCPT_CLIENT_MANAGED)
  89                 sp->client_managed = true;
  90         else
  91                 sp->client_managed = false;
  92
  93         kref_init(&sp->ref);
  94
  95         mutex_unlock(&host->syncpt_mutex);
  96         return sp;
  97
  98 free_base:
  99         host1x_syncpt_base_free(sp->base);
 100         sp->base = NULL;
 101 unlock:
 102         mutex_unlock(&host->syncpt_mutex);
 103         return NULL;
 104 }
 105 EXPORT_SYMBOL(host1x_syncpt_alloc);
 106
 107 /**
 108  * host1x_syncpt_id() - retrieve syncpoint ID
 109  * @sp: host1x syncpoint
 110  *
 111  * Given a pointer to a struct host1x_syncpt, retrieves its ID. This ID is
 112  * often used as a value to program into registers that control how hardware
 113  * blocks interact with syncpoints.
 114  */
 115 u32 host1x_syncpt_id(struct host1x_syncpt *sp)
 116 {
 117         return sp->id;
 118 }
 119 EXPORT_SYMBOL(host1x_syncpt_id);
 120
 121 /**
 122  * host1x_syncpt_incr_max() - update the value sent to hardware
 123  * @sp: host1x syncpoint
 124  * @incrs: number of increments
 125  */
 126 u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs)
 127 {
 128         return (u32)atomic_add_return(incrs, &sp->max_val);
 129 }
 130 EXPORT_SYMBOL(host1x_syncpt_incr_max);
 131
 132  /*
 133  * Write cached syncpoint and waitbase values to hardware.
 134  */
 135 void host1x_syncpt_restore(struct host1x *host)
 136 {
 137         struct host1x_syncpt *sp_base = host->syncpt;
 138         unsigned int i;
 139
 140         for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
 141                 /*
 142                  * Unassign syncpt from channels for purposes of Tegra186
 143                  * syncpoint protection. This prevents any channel from
 144                  * accessing it until it is reassigned.
 145                  */
 146                 host1x_hw_syncpt_assign_to_channel(host, sp_base + i, NULL);
 147                 host1x_hw_syncpt_restore(host, sp_base + i);
 148         }
 149
 150         for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
 151                 host1x_hw_syncpt_restore_wait_base(host, sp_base + i);
 152
 153         host1x_hw_syncpt_enable_protection(host);
 154
 155         wmb();
 156 }
 157
 158 /*
 159  * Update the cached syncpoint and waitbase values by reading them
 160  * from the registers.
 161   */
 162 void host1x_syncpt_save(struct host1x *host)
 163 {
 164         struct host1x_syncpt *sp_base = host->syncpt;
 165         unsigned int i;
 166
 167         for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
 168                 if (host1x_syncpt_client_managed(sp_base + i))
 169                         host1x_hw_syncpt_load(host, sp_base + i);
 170                 else
 171                         WARN_ON(!host1x_syncpt_idle(sp_base + i));
 172         }
 173
 174         for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
 175                 host1x_hw_syncpt_load_wait_base(host, sp_base + i);
 176 }
 177
 178 /*
 179  * Updates the cached syncpoint value by reading a new value from the hardware
 180  * register
 181  */
 182 u32 host1x_syncpt_load(struct host1x_syncpt *sp)
 183 {
 184         u32 val;
 185
 186         val = host1x_hw_syncpt_load(sp->host, sp);
 187         trace_host1x_syncpt_load_min(sp->id, val);
 188
 189         return val;
 190 }
 191
 192 /*
 193  * Get the current syncpoint base
 194  */
 195 u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp)
 196 {
 197         host1x_hw_syncpt_load_wait_base(sp->host, sp);
 198
 199         return sp->base_val;
 200 }
 201
 202 /**
 203  * host1x_syncpt_incr() - increment syncpoint value from CPU, updating cache
 204  * @sp: host1x syncpoint
 205  */
 206 int host1x_syncpt_incr(struct host1x_syncpt *sp)
 207 {
 208         return host1x_hw_syncpt_cpu_incr(sp->host, sp);
 209 }
 210 EXPORT_SYMBOL(host1x_syncpt_incr);
 211
 212 /*
 213  * Updated sync point form hardware, and returns true if syncpoint is expired,
 214  * false if we may need to wait
 215  */
 216 static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh)
 217 {
 218         host1x_hw_syncpt_load(sp->host, sp);
 219
 220         return host1x_syncpt_is_expired(sp, thresh);
 221 }
 222
 223 /**
 224  * host1x_syncpt_wait() - wait for a syncpoint to reach a given value
 225  * @sp: host1x syncpoint
 226  * @thresh: threshold
 227  * @timeout: maximum time to wait for the syncpoint to reach the given value
 228  * @value: return location for the syncpoint value
 229  */
 230 int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
 231                        u32 *value)
 232 {
 233         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
 234         void *ref;
 235         struct host1x_waitlist *waiter;
 236         int err = 0, check_count = 0;
 237
 238         if (value)
 239                 *value = host1x_syncpt_load(sp);
 240
 241         if (host1x_syncpt_is_expired(sp, thresh))
 242                 return 0;
 243
 244         if (!timeout) {
 245                 err = -EAGAIN;
 246                 goto done;
 247         }
 248
 249         /* allocate a waiter */
 250         waiter = kzalloc(sizeof(*waiter), GFP_KERNEL);
 251         if (!waiter) {
 252                 err = -ENOMEM;
 253                 goto done;
 254         }
 255
 256         /* schedule a wakeup when the syncpoint value is reached */
 257         err = host1x_intr_add_action(sp->host, sp, thresh,
 258                                      HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE,
 259                                      &wq, waiter, &ref);
 260         if (err)
 261                 goto done;
 262
 263         err = -EAGAIN;
 264         /* Caller-specified timeout may be impractically low */
 265         if (timeout < 0)
 266                 timeout = LONG_MAX;
 267
 268         /* wait for the syncpoint, or timeout, or signal */
 269         while (timeout) {
 270                 long check = min_t(long, SYNCPT_CHECK_PERIOD, timeout);
 271                 int remain;
 272
 273                 remain = wait_event_interruptible_timeout(wq,
 274                                 syncpt_load_min_is_expired(sp, thresh),
 275                                 check);
 276                 if (remain > 0 || host1x_syncpt_is_expired(sp, thresh)) {
 277                         if (value)
 278                                 *value = host1x_syncpt_load(sp);
 279
 280                         err = 0;
 281
 282                         break;
 283                 }
 284
 285                 if (remain < 0) {
 286                         err = remain;
 287                         break;
 288                 }
 289
 290                 timeout -= check;
 291
 292                 if (timeout && check_count <= MAX_STUCK_CHECK_COUNT) {
 293                         dev_warn(sp->host->dev,
 294                                 "%s: syncpoint id %u (%s) stuck waiting %d, timeout=%ld\n",
 295                                  current->comm, sp->id, sp->name,
 296                                  thresh, timeout);
 297
 298                         host1x_debug_dump_syncpts(sp->host);
 299
 300                         if (check_count == MAX_STUCK_CHECK_COUNT)
 301                                 host1x_debug_dump(sp->host);
 302
 303                         check_count++;
 304                 }
 305         }
 306
 307         host1x_intr_put_ref(sp->host, sp->id, ref, true);
 308
 309 done:
 310         return err;
 311 }
 312 EXPORT_SYMBOL(host1x_syncpt_wait);
 313
 314 /*
 315  * Returns true if syncpoint is expired, false if we may need to wait
 316  */
 317 bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh)
 318 {
 319         u32 current_val;
 320
 321         smp_rmb();
 322
 323         current_val = (u32)atomic_read(&sp->min_val);
 324
 325         return ((current_val - thresh) & 0x80000000U) == 0U;
 326 }
 327
 328 int host1x_syncpt_init(struct host1x *host)
 329 {
 330         struct host1x_syncpt_base *bases;
 331         struct host1x_syncpt *syncpt;
 332         unsigned int i;
 333
 334         syncpt = devm_kcalloc(host->dev, host->info->nb_pts, sizeof(*syncpt),
 335                               GFP_KERNEL);
 336         if (!syncpt)
 337                 return -ENOMEM;
 338
 339         bases = devm_kcalloc(host->dev, host->info->nb_bases, sizeof(*bases),
 340                              GFP_KERNEL);
 341         if (!bases)
 342                 return -ENOMEM;
 343
 344         for (i = 0; i < host->info->nb_pts; i++) {
 345                 syncpt[i].id = i;
 346                 syncpt[i].host = host;
 347         }
 348
 349         for (i = 0; i < host->info->nb_bases; i++)
 350                 bases[i].id = i;
 351
 352         mutex_init(&host->syncpt_mutex);
 353         host->syncpt = syncpt;
 354         host->bases = bases;
 355
 356         /* Allocate sync point to use for clearing waits for expired fences */
 357         host->nop_sp = host1x_syncpt_alloc(host, 0, "reserved-nop");
 358         if (!host->nop_sp)
 359                 return -ENOMEM;
 360
 361         if (host->info->reserve_vblank_syncpts) {
 362                 kref_init(&host->syncpt[26].ref);
 363                 kref_init(&host->syncpt[27].ref);
 364         }
 365
 366         return 0;
 367 }
 368
 369 /**
 370  * host1x_syncpt_request() - request a syncpoint
 371  * @client: client requesting the syncpoint
 372  * @flags: flags
 373  *
 374  * host1x client drivers can use this function to allocate a syncpoint for
 375  * subsequent use. A syncpoint returned by this function will be reserved for
 376  * use by the client exclusively. When no longer using a syncpoint, a host1x
 377  * client driver needs to release it using host1x_syncpt_put().
 378  */
 379 struct host1x_syncpt *host1x_syncpt_request(struct host1x_client *client,
 380                                             unsigned long flags)
 381 {
 382         struct host1x *host = dev_get_drvdata(client->host->parent);
 383
 384         return host1x_syncpt_alloc(host, flags, dev_name(client->dev));
 385 }
 386 EXPORT_SYMBOL(host1x_syncpt_request);
 387
 388 static void syncpt_release(struct kref *ref)
 389 {
 390         struct host1x_syncpt *sp = container_of(ref, struct host1x_syncpt, ref);
 391
 392         atomic_set(&sp->max_val, host1x_syncpt_read(sp));
 393
 394         sp->locked = false;
 395
 396         mutex_lock(&sp->host->syncpt_mutex);
 397
 398         host1x_syncpt_base_free(sp->base);
 399         kfree(sp->name);
 400         sp->base = NULL;
 401         sp->name = NULL;
 402         sp->client_managed = false;
 403
 404         mutex_unlock(&sp->host->syncpt_mutex);
 405 }
 406
 407 /**
 408  * host1x_syncpt_put() - free a requested syncpoint
 409  * @sp: host1x syncpoint
 410  *
 411  * Release a syncpoint previously allocated using host1x_syncpt_request(). A
 412  * host1x client driver should call this when the syncpoint is no longer in
 413  * use.
 414  */
 415 void host1x_syncpt_put(struct host1x_syncpt *sp)
 416 {
 417         if (!sp)
 418                 return;
 419
 420         kref_put(&sp->ref, syncpt_release);
 421 }
 422 EXPORT_SYMBOL(host1x_syncpt_put);
 423
 424 void host1x_syncpt_deinit(struct host1x *host)
 425 {
 426         struct host1x_syncpt *sp = host->syncpt;
 427         unsigned int i;
 428
 429         for (i = 0; i < host->info->nb_pts; i++, sp++)
 430                 kfree(sp->name);
 431 }
 432
 433 /**
 434  * host1x_syncpt_read_max() - read maximum syncpoint value
 435  * @sp: host1x syncpoint
 436  *
 437  * The maximum syncpoint value indicates how many operations there are in
 438  * queue, either in channel or in a software thread.
 439  */
 440 u32 host1x_syncpt_read_max(struct host1x_syncpt *sp)
 441 {
 442         smp_rmb();
 443
 444         return (u32)atomic_read(&sp->max_val);
 445 }
 446 EXPORT_SYMBOL(host1x_syncpt_read_max);
 447
 448 /**
 449  * host1x_syncpt_read_min() - read minimum syncpoint value
 450  * @sp: host1x syncpoint
 451  *
 452  * The minimum syncpoint value is a shadow of the current sync point value in
 453  * hardware.
 454  */
 455 u32 host1x_syncpt_read_min(struct host1x_syncpt *sp)
 456 {
 457         smp_rmb();
 458
 459         return (u32)atomic_read(&sp->min_val);
 460 }
 461 EXPORT_SYMBOL(host1x_syncpt_read_min);
 462
 463 /**
 464  * host1x_syncpt_read() - read the current syncpoint value
 465  * @sp: host1x syncpoint
 466  */
 467 u32 host1x_syncpt_read(struct host1x_syncpt *sp)
 468 {
 469         return host1x_syncpt_load(sp);
 470 }
 471 EXPORT_SYMBOL(host1x_syncpt_read);
 472
 473 unsigned int host1x_syncpt_nb_pts(struct host1x *host)
 474 {
 475         return host->info->nb_pts;
 476 }
 477
 478 unsigned int host1x_syncpt_nb_bases(struct host1x *host)
 479 {
 480         return host->info->nb_bases;
 481 }
 482
 483 unsigned int host1x_syncpt_nb_mlocks(struct host1x *host)
 484 {
 485         return host->info->nb_mlocks;
 486 }
 487
 488 /**
 489  * host1x_syncpt_get_by_id() - obtain a syncpoint by ID
 490  * @host: host1x controller
 491  * @id: syncpoint ID
 492  */
 493 struct host1x_syncpt *host1x_syncpt_get_by_id(struct host1x *host,
 494                                               unsigned int id)
 495 {
 496         if (id >= host->info->nb_pts)
 497                 return NULL;
 498
 499         if (kref_get_unless_zero(&host->syncpt[id].ref))
 500                 return &host->syncpt[id];
 501         else
 502                 return NULL;
 503 }
 504 EXPORT_SYMBOL(host1x_syncpt_get_by_id);
 505
 506 /**
 507  * host1x_syncpt_get_by_id_noref() - obtain a syncpoint by ID but don't
 508  *      increase the refcount.
 509  * @host: host1x controller
 510  * @id: syncpoint ID
 511  */
 512 struct host1x_syncpt *host1x_syncpt_get_by_id_noref(struct host1x *host,
 513                                                     unsigned int id)
 514 {
 515         if (id >= host->info->nb_pts)
 516                 return NULL;
 517
 518         return &host->syncpt[id];
 519 }
 520 EXPORT_SYMBOL(host1x_syncpt_get_by_id_noref);
 521
 522 /**
 523  * host1x_syncpt_get() - increment syncpoint refcount
 524  * @sp: syncpoint
 525  */
 526 struct host1x_syncpt *host1x_syncpt_get(struct host1x_syncpt *sp)
 527 {
 528         kref_get(&sp->ref);
 529
 530         return sp;
 531 }
 532 EXPORT_SYMBOL(host1x_syncpt_get);
 533
 534 /**
 535  * host1x_syncpt_get_base() - obtain the wait base associated with a syncpoint
 536  * @sp: host1x syncpoint
 537  */
 538 struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp)
 539 {
 540         return sp ? sp->base : NULL;
 541 }
 542 EXPORT_SYMBOL(host1x_syncpt_get_base);
 543
 544 /**
 545  * host1x_syncpt_base_id() - retrieve the ID of a syncpoint wait base
 546  * @base: host1x syncpoint wait base
 547  */
 548 u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base)
 549 {
 550         return base->id;
 551 }
 552 EXPORT_SYMBOL(host1x_syncpt_base_id);
 553
 554 static void do_nothing(struct kref *ref)
 555 {
 556 }
 557
 558 /**
 559  * host1x_syncpt_release_vblank_reservation() - Make VBLANK syncpoint
 560  *   available for allocation
 561  *
 562  * @client: host1x bus client
 563  * @syncpt_id: syncpoint ID to make available
 564  *
 565  * Makes VBLANK<i> syncpoint available for allocatation if it was
 566  * reserved at initialization time. This should be called by the display
 567  * driver after it has ensured that any VBLANK increment programming configured
 568  * by the boot chain has been disabled.
 569  */
 570 void host1x_syncpt_release_vblank_reservation(struct host1x_client *client,
 571                                               u32 syncpt_id)
 572 {
 573         struct host1x *host = dev_get_drvdata(client->host->parent);
 574
 575         if (!host->info->reserve_vblank_syncpts)
 576                 return;
 577
 578         kref_put(&host->syncpt[syncpt_id].ref, do_nothing);
 579 }
 580 EXPORT_SYMBOL(host1x_syncpt_release_vblank_reservation);