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                 host1x_hw_syncpt_restore(host, sp_base + i);
 142
 143         for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
 144                 host1x_hw_syncpt_restore_wait_base(host, sp_base + i);
 145
 146         host1x_hw_syncpt_enable_protection(host);
 147
 148         wmb();
 149 }
 150
 151 /*
 152  * Update the cached syncpoint and waitbase values by reading them
 153  * from the registers.
 154   */
 155 void host1x_syncpt_save(struct host1x *host)
 156 {
 157         struct host1x_syncpt *sp_base = host->syncpt;
 158         unsigned int i;
 159
 160         for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
 161                 if (host1x_syncpt_client_managed(sp_base + i))
 162                         host1x_hw_syncpt_load(host, sp_base + i);
 163                 else
 164                         WARN_ON(!host1x_syncpt_idle(sp_base + i));
 165         }
 166
 167         for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
 168                 host1x_hw_syncpt_load_wait_base(host, sp_base + i);
 169 }
 170
 171 /*
 172  * Updates the cached syncpoint value by reading a new value from the hardware
 173  * register
 174  */
 175 u32 host1x_syncpt_load(struct host1x_syncpt *sp)
 176 {
 177         u32 val;
 178
 179         val = host1x_hw_syncpt_load(sp->host, sp);
 180         trace_host1x_syncpt_load_min(sp->id, val);
 181
 182         return val;
 183 }
 184
 185 /*
 186  * Get the current syncpoint base
 187  */
 188 u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp)
 189 {
 190         host1x_hw_syncpt_load_wait_base(sp->host, sp);
 191
 192         return sp->base_val;
 193 }
 194
 195 /**
 196  * host1x_syncpt_incr() - increment syncpoint value from CPU, updating cache
 197  * @sp: host1x syncpoint
 198  */
 199 int host1x_syncpt_incr(struct host1x_syncpt *sp)
 200 {
 201         return host1x_hw_syncpt_cpu_incr(sp->host, sp);
 202 }
 203 EXPORT_SYMBOL(host1x_syncpt_incr);
 204
 205 /*
 206  * Updated sync point form hardware, and returns true if syncpoint is expired,
 207  * false if we may need to wait
 208  */
 209 static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh)
 210 {
 211         host1x_hw_syncpt_load(sp->host, sp);
 212
 213         return host1x_syncpt_is_expired(sp, thresh);
 214 }
 215
 216 /**
 217  * host1x_syncpt_wait() - wait for a syncpoint to reach a given value
 218  * @sp: host1x syncpoint
 219  * @thresh: threshold
 220  * @timeout: maximum time to wait for the syncpoint to reach the given value
 221  * @value: return location for the syncpoint value
 222  */
 223 int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
 224                        u32 *value)
 225 {
 226         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
 227         void *ref;
 228         struct host1x_waitlist *waiter;
 229         int err = 0, check_count = 0;
 230         u32 val;
 231
 232         if (value)
 233                 *value = 0;
 234
 235         /* first check cache */
 236         if (host1x_syncpt_is_expired(sp, thresh)) {
 237                 if (value)
 238                         *value = host1x_syncpt_load(sp);
 239
 240                 return 0;
 241         }
 242
 243         /* try to read from register */
 244         val = host1x_hw_syncpt_load(sp->host, sp);
 245         if (host1x_syncpt_is_expired(sp, thresh)) {
 246                 if (value)
 247                         *value = val;
 248
 249                 goto done;
 250         }
 251
 252         if (!timeout) {
 253                 err = -EAGAIN;
 254                 goto done;
 255         }
 256
 257         /* allocate a waiter */
 258         waiter = kzalloc(sizeof(*waiter), GFP_KERNEL);
 259         if (!waiter) {
 260                 err = -ENOMEM;
 261                 goto done;
 262         }
 263
 264         /* schedule a wakeup when the syncpoint value is reached */
 265         err = host1x_intr_add_action(sp->host, sp, thresh,
 266                                      HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE,
 267                                      &wq, waiter, &ref);
 268         if (err)
 269                 goto done;
 270
 271         err = -EAGAIN;
 272         /* Caller-specified timeout may be impractically low */
 273         if (timeout < 0)
 274                 timeout = LONG_MAX;
 275
 276         /* wait for the syncpoint, or timeout, or signal */
 277         while (timeout) {
 278                 long check = min_t(long, SYNCPT_CHECK_PERIOD, timeout);
 279                 int remain;
 280
 281                 remain = wait_event_interruptible_timeout(wq,
 282                                 syncpt_load_min_is_expired(sp, thresh),
 283                                 check);
 284                 if (remain > 0 || host1x_syncpt_is_expired(sp, thresh)) {
 285                         if (value)
 286                                 *value = host1x_syncpt_load(sp);
 287
 288                         err = 0;
 289
 290                         break;
 291                 }
 292
 293                 if (remain < 0) {
 294                         err = remain;
 295                         break;
 296                 }
 297
 298                 timeout -= check;
 299
 300                 if (timeout && check_count <= MAX_STUCK_CHECK_COUNT) {
 301                         dev_warn(sp->host->dev,
 302                                 "%s: syncpoint id %u (%s) stuck waiting %d, timeout=%ld\n",
 303                                  current->comm, sp->id, sp->name,
 304                                  thresh, timeout);
 305
 306                         host1x_debug_dump_syncpts(sp->host);
 307
 308                         if (check_count == MAX_STUCK_CHECK_COUNT)
 309                                 host1x_debug_dump(sp->host);
 310
 311                         check_count++;
 312                 }
 313         }
 314
 315         host1x_intr_put_ref(sp->host, sp->id, ref, true);
 316
 317 done:
 318         return err;
 319 }
 320 EXPORT_SYMBOL(host1x_syncpt_wait);
 321
 322 /*
 323  * Returns true if syncpoint is expired, false if we may need to wait
 324  */
 325 bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh)
 326 {
 327         u32 current_val;
 328
 329         smp_rmb();
 330
 331         current_val = (u32)atomic_read(&sp->min_val);
 332
 333         return ((current_val - thresh) & 0x80000000U) == 0U;
 334 }
 335
 336 int host1x_syncpt_init(struct host1x *host)
 337 {
 338         struct host1x_syncpt_base *bases;
 339         struct host1x_syncpt *syncpt;
 340         unsigned int i;
 341
 342         syncpt = devm_kcalloc(host->dev, host->info->nb_pts, sizeof(*syncpt),
 343                               GFP_KERNEL);
 344         if (!syncpt)
 345                 return -ENOMEM;
 346
 347         bases = devm_kcalloc(host->dev, host->info->nb_bases, sizeof(*bases),
 348                              GFP_KERNEL);
 349         if (!bases)
 350                 return -ENOMEM;
 351
 352         for (i = 0; i < host->info->nb_pts; i++) {
 353                 syncpt[i].id = i;
 354                 syncpt[i].host = host;
 355
 356                 /*
 357                  * Unassign syncpt from channels for purposes of Tegra186
 358                  * syncpoint protection. This prevents any channel from
 359                  * accessing it until it is reassigned.
 360                  */
 361                 host1x_hw_syncpt_assign_to_channel(host, &syncpt[i], NULL);
 362         }
 363
 364         for (i = 0; i < host->info->nb_bases; i++)
 365                 bases[i].id = i;
 366
 367         mutex_init(&host->syncpt_mutex);
 368         host->syncpt = syncpt;
 369         host->bases = bases;
 370
 371         /* Allocate sync point to use for clearing waits for expired fences */
 372         host->nop_sp = host1x_syncpt_alloc(host, 0, "reserved-nop");
 373         if (!host->nop_sp)
 374                 return -ENOMEM;
 375
 376         if (host->info->reserve_vblank_syncpts) {
 377                 kref_init(&host->syncpt[26].ref);
 378                 kref_init(&host->syncpt[27].ref);
 379         }
 380
 381         return 0;
 382 }
 383
 384 /**
 385  * host1x_syncpt_request() - request a syncpoint
 386  * @client: client requesting the syncpoint
 387  * @flags: flags
 388  *
 389  * host1x client drivers can use this function to allocate a syncpoint for
 390  * subsequent use. A syncpoint returned by this function will be reserved for
 391  * use by the client exclusively. When no longer using a syncpoint, a host1x
 392  * client driver needs to release it using host1x_syncpt_put().
 393  */
 394 struct host1x_syncpt *host1x_syncpt_request(struct host1x_client *client,
 395                                             unsigned long flags)
 396 {
 397         struct host1x *host = dev_get_drvdata(client->host->parent);
 398
 399         return host1x_syncpt_alloc(host, flags, dev_name(client->dev));
 400 }
 401 EXPORT_SYMBOL(host1x_syncpt_request);
 402
 403 static void syncpt_release(struct kref *ref)
 404 {
 405         struct host1x_syncpt *sp = container_of(ref, struct host1x_syncpt, ref);
 406
 407         atomic_set(&sp->max_val, host1x_syncpt_read(sp));
 408
 409         sp->locked = false;
 410
 411         mutex_lock(&sp->host->syncpt_mutex);
 412
 413         host1x_syncpt_base_free(sp->base);
 414         kfree(sp->name);
 415         sp->base = NULL;
 416         sp->name = NULL;
 417         sp->client_managed = false;
 418
 419         mutex_unlock(&sp->host->syncpt_mutex);
 420 }
 421
 422 /**
 423  * host1x_syncpt_put() - free a requested syncpoint
 424  * @sp: host1x syncpoint
 425  *
 426  * Release a syncpoint previously allocated using host1x_syncpt_request(). A
 427  * host1x client driver should call this when the syncpoint is no longer in
 428  * use.
 429  */
 430 void host1x_syncpt_put(struct host1x_syncpt *sp)
 431 {
 432         if (!sp)
 433                 return;
 434
 435         kref_put(&sp->ref, syncpt_release);
 436 }
 437 EXPORT_SYMBOL(host1x_syncpt_put);
 438
 439 void host1x_syncpt_deinit(struct host1x *host)
 440 {
 441         struct host1x_syncpt *sp = host->syncpt;
 442         unsigned int i;
 443
 444         for (i = 0; i < host->info->nb_pts; i++, sp++)
 445                 kfree(sp->name);
 446 }
 447
 448 /**
 449  * host1x_syncpt_read_max() - read maximum syncpoint value
 450  * @sp: host1x syncpoint
 451  *
 452  * The maximum syncpoint value indicates how many operations there are in
 453  * queue, either in channel or in a software thread.
 454  */
 455 u32 host1x_syncpt_read_max(struct host1x_syncpt *sp)
 456 {
 457         smp_rmb();
 458
 459         return (u32)atomic_read(&sp->max_val);
 460 }
 461 EXPORT_SYMBOL(host1x_syncpt_read_max);
 462
 463 /**
 464  * host1x_syncpt_read_min() - read minimum syncpoint value
 465  * @sp: host1x syncpoint
 466  *
 467  * The minimum syncpoint value is a shadow of the current sync point value in
 468  * hardware.
 469  */
 470 u32 host1x_syncpt_read_min(struct host1x_syncpt *sp)
 471 {
 472         smp_rmb();
 473
 474         return (u32)atomic_read(&sp->min_val);
 475 }
 476 EXPORT_SYMBOL(host1x_syncpt_read_min);
 477
 478 /**
 479  * host1x_syncpt_read() - read the current syncpoint value
 480  * @sp: host1x syncpoint
 481  */
 482 u32 host1x_syncpt_read(struct host1x_syncpt *sp)
 483 {
 484         return host1x_syncpt_load(sp);
 485 }
 486 EXPORT_SYMBOL(host1x_syncpt_read);
 487
 488 unsigned int host1x_syncpt_nb_pts(struct host1x *host)
 489 {
 490         return host->info->nb_pts;
 491 }
 492
 493 unsigned int host1x_syncpt_nb_bases(struct host1x *host)
 494 {
 495         return host->info->nb_bases;
 496 }
 497
 498 unsigned int host1x_syncpt_nb_mlocks(struct host1x *host)
 499 {
 500         return host->info->nb_mlocks;
 501 }
 502
 503 /**
 504  * host1x_syncpt_get_by_id() - obtain a syncpoint by ID
 505  * @host: host1x controller
 506  * @id: syncpoint ID
 507  */
 508 struct host1x_syncpt *host1x_syncpt_get_by_id(struct host1x *host,
 509                                               unsigned int id)
 510 {
 511         if (id >= host->info->nb_pts)
 512                 return NULL;
 513
 514         if (kref_get_unless_zero(&host->syncpt[id].ref))
 515                 return &host->syncpt[id];
 516         else
 517                 return NULL;
 518 }
 519 EXPORT_SYMBOL(host1x_syncpt_get_by_id);
 520
 521 /**
 522  * host1x_syncpt_get_by_id_noref() - obtain a syncpoint by ID but don't
 523  *      increase the refcount.
 524  * @host: host1x controller
 525  * @id: syncpoint ID
 526  */
 527 struct host1x_syncpt *host1x_syncpt_get_by_id_noref(struct host1x *host,
 528                                                     unsigned int id)
 529 {
 530         if (id >= host->info->nb_pts)
 531                 return NULL;
 532
 533         return &host->syncpt[id];
 534 }
 535 EXPORT_SYMBOL(host1x_syncpt_get_by_id_noref);
 536
 537 /**
 538  * host1x_syncpt_get() - increment syncpoint refcount
 539  * @sp: syncpoint
 540  */
 541 struct host1x_syncpt *host1x_syncpt_get(struct host1x_syncpt *sp)
 542 {
 543         kref_get(&sp->ref);
 544
 545         return sp;
 546 }
 547 EXPORT_SYMBOL(host1x_syncpt_get);
 548
 549 /**
 550  * host1x_syncpt_get_base() - obtain the wait base associated with a syncpoint
 551  * @sp: host1x syncpoint
 552  */
 553 struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp)
 554 {
 555         return sp ? sp->base : NULL;
 556 }
 557 EXPORT_SYMBOL(host1x_syncpt_get_base);
 558
 559 /**
 560  * host1x_syncpt_base_id() - retrieve the ID of a syncpoint wait base
 561  * @base: host1x syncpoint wait base
 562  */
 563 u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base)
 564 {
 565         return base->id;
 566 }
 567 EXPORT_SYMBOL(host1x_syncpt_base_id);
 568
 569 static void do_nothing(struct kref *ref)
 570 {
 571 }
 572
 573 /**
 574  * host1x_syncpt_release_vblank_reservation() - Make VBLANK syncpoint
 575  *   available for allocation
 576  *
 577  * @client: host1x bus client
 578  * @syncpt_id: syncpoint ID to make available
 579  *
 580  * Makes VBLANK<i> syncpoint available for allocatation if it was
 581  * reserved at initialization time. This should be called by the display
 582  * driver after it has ensured that any VBLANK increment programming configured
 583  * by the boot chain has been disabled.
 584  */
 585 void host1x_syncpt_release_vblank_reservation(struct host1x_client *client,
 586                                               u32 syncpt_id)
 587 {
 588         struct host1x *host = dev_get_drvdata(client->host->parent);
 589
 590         if (!host->info->reserve_vblank_syncpts)
 591                 return;
 592
 593         kref_put(&host->syncpt[syncpt_id].ref, do_nothing);
 594 }
 595 EXPORT_SYMBOL(host1x_syncpt_release_vblank_reservation);