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/dma-fence.h>
  11 #include <linux/slab.h>
  12
  13 #include <trace/events/host1x.h>
  14
  15 #include "syncpt.h"
  16 #include "dev.h"
  17 #include "intr.h"
  18 #include "debug.h"
  19
  20 #define SYNCPT_CHECK_PERIOD (2 * HZ)
  21 #define MAX_STUCK_CHECK_COUNT 15
  22
  23 static struct host1x_syncpt_base *
  24 host1x_syncpt_base_request(struct host1x *host)
  25 {
  26         struct host1x_syncpt_base *bases = host->bases;
  27         unsigned int i;
  28
  29         for (i = 0; i < host->info->nb_bases; i++)
  30                 if (!bases[i].requested)
  31                         break;
  32
  33         if (i >= host->info->nb_bases)
  34                 return NULL;
  35
  36         bases[i].requested = true;
  37         return &bases[i];
  38 }
  39
  40 static void host1x_syncpt_base_free(struct host1x_syncpt_base *base)
  41 {
  42         if (base)
  43                 base->requested = false;
  44 }
  45
  46 /**
  47  * host1x_syncpt_alloc() - allocate a syncpoint
  48  * @host: host1x device data
  49  * @flags: bitfield of HOST1X_SYNCPT_* flags
  50  * @name: name for the syncpoint for use in debug prints
  51  *
  52  * Allocates a hardware syncpoint for the caller's use. The caller then has
  53  * the sole authority to mutate the syncpoint's value until it is freed again.
  54  *
  55  * If no free syncpoints are available, or a NULL name was specified, returns
  56  * NULL.
  57  */
  58 struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host,
  59                                           unsigned long flags,
  60                                           const char *name)
  61 {
  62         struct host1x_syncpt *sp = host->syncpt;
  63         char *full_name;
  64         unsigned int i;
  65
  66         if (!name)
  67                 return NULL;
  68
  69         mutex_lock(&host->syncpt_mutex);
  70
  71         for (i = 0; i < host->info->nb_pts && kref_read(&sp->ref); i++, sp++)
  72                 ;
  73
  74         if (i >= host->info->nb_pts)
  75                 goto unlock;
  76
  77         if (flags & HOST1X_SYNCPT_HAS_BASE) {
  78                 sp->base = host1x_syncpt_base_request(host);
  79                 if (!sp->base)
  80                         goto unlock;
  81         }
  82
  83         full_name = kasprintf(GFP_KERNEL, "%u-%s", sp->id, name);
  84         if (!full_name)
  85                 goto free_base;
  86
  87         sp->name = full_name;
  88
  89         if (flags & HOST1X_SYNCPT_CLIENT_MANAGED)
  90                 sp->client_managed = true;
  91         else
  92                 sp->client_managed = false;
  93
  94         kref_init(&sp->ref);
  95
  96         mutex_unlock(&host->syncpt_mutex);
  97         return sp;
  98
  99 free_base:
 100         host1x_syncpt_base_free(sp->base);
 101         sp->base = NULL;
 102 unlock:
 103         mutex_unlock(&host->syncpt_mutex);
 104         return NULL;
 105 }
 106 EXPORT_SYMBOL(host1x_syncpt_alloc);
 107
 108 /**
 109  * host1x_syncpt_id() - retrieve syncpoint ID
 110  * @sp: host1x syncpoint
 111  *
 112  * Given a pointer to a struct host1x_syncpt, retrieves its ID. This ID is
 113  * often used as a value to program into registers that control how hardware
 114  * blocks interact with syncpoints.
 115  */
 116 u32 host1x_syncpt_id(struct host1x_syncpt *sp)
 117 {
 118         return sp->id;
 119 }
 120 EXPORT_SYMBOL(host1x_syncpt_id);
 121
 122 /**
 123  * host1x_syncpt_incr_max() - update the value sent to hardware
 124  * @sp: host1x syncpoint
 125  * @incrs: number of increments
 126  */
 127 u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs)
 128 {
 129         return (u32)atomic_add_return(incrs, &sp->max_val);
 130 }
 131 EXPORT_SYMBOL(host1x_syncpt_incr_max);
 132
 133  /*
 134  * Write cached syncpoint and waitbase values to hardware.
 135  */
 136 void host1x_syncpt_restore(struct host1x *host)
 137 {
 138         struct host1x_syncpt *sp_base = host->syncpt;
 139         unsigned int i;
 140
 141         for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
 142                 /*
 143                  * Unassign syncpt from channels for purposes of Tegra186
 144                  * syncpoint protection. This prevents any channel from
 145                  * accessing it until it is reassigned.
 146                  */
 147                 host1x_hw_syncpt_assign_to_channel(host, sp_base + i, NULL);
 148                 host1x_hw_syncpt_restore(host, sp_base + i);
 149         }
 150
 151         for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
 152                 host1x_hw_syncpt_restore_wait_base(host, sp_base + i);
 153
 154         host1x_hw_syncpt_enable_protection(host);
 155
 156         wmb();
 157 }
 158
 159 /*
 160  * Update the cached syncpoint and waitbase values by reading them
 161  * from the registers.
 162   */
 163 void host1x_syncpt_save(struct host1x *host)
 164 {
 165         struct host1x_syncpt *sp_base = host->syncpt;
 166         unsigned int i;
 167
 168         for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
 169                 if (host1x_syncpt_client_managed(sp_base + i))
 170                         host1x_hw_syncpt_load(host, sp_base + i);
 171                 else
 172                         WARN_ON(!host1x_syncpt_idle(sp_base + i));
 173         }
 174
 175         for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
 176                 host1x_hw_syncpt_load_wait_base(host, sp_base + i);
 177 }
 178
 179 /*
 180  * Updates the cached syncpoint value by reading a new value from the hardware
 181  * register
 182  */
 183 u32 host1x_syncpt_load(struct host1x_syncpt *sp)
 184 {
 185         u32 val;
 186
 187         val = host1x_hw_syncpt_load(sp->host, sp);
 188         trace_host1x_syncpt_load_min(sp->id, val);
 189
 190         return val;
 191 }
 192
 193 /*
 194  * Get the current syncpoint base
 195  */
 196 u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp)
 197 {
 198         host1x_hw_syncpt_load_wait_base(sp->host, sp);
 199
 200         return sp->base_val;
 201 }
 202
 203 /**
 204  * host1x_syncpt_incr() - increment syncpoint value from CPU, updating cache
 205  * @sp: host1x syncpoint
 206  */
 207 int host1x_syncpt_incr(struct host1x_syncpt *sp)
 208 {
 209         return host1x_hw_syncpt_cpu_incr(sp->host, sp);
 210 }
 211 EXPORT_SYMBOL(host1x_syncpt_incr);
 212
 213 /**
 214  * host1x_syncpt_wait() - wait for a syncpoint to reach a given value
 215  * @sp: host1x syncpoint
 216  * @thresh: threshold
 217  * @timeout: maximum time to wait for the syncpoint to reach the given value
 218  * @value: return location for the syncpoint value
 219  */
 220 int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
 221                        u32 *value)
 222 {
 223         struct dma_fence *fence;
 224         long wait_err;
 225
 226         host1x_hw_syncpt_load(sp->host, sp);
 227
 228         if (value)
 229                 *value = host1x_syncpt_load(sp);
 230
 231         if (host1x_syncpt_is_expired(sp, thresh))
 232                 return 0;
 233
 234         if (timeout < 0)
 235                 timeout = LONG_MAX;
 236         else if (timeout == 0)
 237                 return -EAGAIN;
 238
 239         fence = host1x_fence_create(sp, thresh, false);
 240         if (IS_ERR(fence))
 241                 return PTR_ERR(fence);
 242
 243         wait_err = dma_fence_wait_timeout(fence, true, timeout);
 244         if (wait_err == 0)
 245                 host1x_fence_cancel(fence);
 246         dma_fence_put(fence);
 247
 248         if (value)
 249                 *value = host1x_syncpt_load(sp);
 250
 251         /*
 252          * Don't rely on dma_fence_wait_timeout return value,
 253          * since it returns zero both on timeout and if the
 254          * wait completed with 0 jiffies left.
 255          */
 256         host1x_hw_syncpt_load(sp->host, sp);
 257         if (wait_err == 0 && !host1x_syncpt_is_expired(sp, thresh))
 258                 return -EAGAIN;
 259         else if (wait_err < 0)
 260                 return wait_err;
 261         else
 262                 return 0;
 263 }
 264 EXPORT_SYMBOL(host1x_syncpt_wait);
 265
 266 /*
 267  * Returns true if syncpoint is expired, false if we may need to wait
 268  */
 269 bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh)
 270 {
 271         u32 current_val;
 272
 273         smp_rmb();
 274
 275         current_val = (u32)atomic_read(&sp->min_val);
 276
 277         return ((current_val - thresh) & 0x80000000U) == 0U;
 278 }
 279
 280 int host1x_syncpt_init(struct host1x *host)
 281 {
 282         struct host1x_syncpt_base *bases;
 283         struct host1x_syncpt *syncpt;
 284         unsigned int i;
 285
 286         syncpt = devm_kcalloc(host->dev, host->info->nb_pts, sizeof(*syncpt),
 287                               GFP_KERNEL);
 288         if (!syncpt)
 289                 return -ENOMEM;
 290
 291         bases = devm_kcalloc(host->dev, host->info->nb_bases, sizeof(*bases),
 292                              GFP_KERNEL);
 293         if (!bases)
 294                 return -ENOMEM;
 295
 296         for (i = 0; i < host->info->nb_pts; i++) {
 297                 syncpt[i].id = i;
 298                 syncpt[i].host = host;
 299         }
 300
 301         for (i = 0; i < host->info->nb_bases; i++)
 302                 bases[i].id = i;
 303
 304         mutex_init(&host->syncpt_mutex);
 305         host->syncpt = syncpt;
 306         host->bases = bases;
 307
 308         /* Allocate sync point to use for clearing waits for expired fences */
 309         host->nop_sp = host1x_syncpt_alloc(host, 0, "reserved-nop");
 310         if (!host->nop_sp)
 311                 return -ENOMEM;
 312
 313         if (host->info->reserve_vblank_syncpts) {
 314                 kref_init(&host->syncpt[26].ref);
 315                 kref_init(&host->syncpt[27].ref);
 316         }
 317
 318         return 0;
 319 }
 320
 321 /**
 322  * host1x_syncpt_request() - request a syncpoint
 323  * @client: client requesting the syncpoint
 324  * @flags: flags
 325  *
 326  * host1x client drivers can use this function to allocate a syncpoint for
 327  * subsequent use. A syncpoint returned by this function will be reserved for
 328  * use by the client exclusively. When no longer using a syncpoint, a host1x
 329  * client driver needs to release it using host1x_syncpt_put().
 330  */
 331 struct host1x_syncpt *host1x_syncpt_request(struct host1x_client *client,
 332                                             unsigned long flags)
 333 {
 334         struct host1x *host = dev_get_drvdata(client->host->parent);
 335
 336         return host1x_syncpt_alloc(host, flags, dev_name(client->dev));
 337 }
 338 EXPORT_SYMBOL(host1x_syncpt_request);
 339
 340 static void syncpt_release(struct kref *ref)
 341 {
 342         struct host1x_syncpt *sp = container_of(ref, struct host1x_syncpt, ref);
 343
 344         atomic_set(&sp->max_val, host1x_syncpt_read(sp));
 345
 346         sp->locked = false;
 347
 348         mutex_lock(&sp->host->syncpt_mutex);
 349
 350         host1x_syncpt_base_free(sp->base);
 351         kfree(sp->name);
 352         sp->base = NULL;
 353         sp->name = NULL;
 354         sp->client_managed = false;
 355
 356         mutex_unlock(&sp->host->syncpt_mutex);
 357 }
 358
 359 /**
 360  * host1x_syncpt_put() - free a requested syncpoint
 361  * @sp: host1x syncpoint
 362  *
 363  * Release a syncpoint previously allocated using host1x_syncpt_request(). A
 364  * host1x client driver should call this when the syncpoint is no longer in
 365  * use.
 366  */
 367 void host1x_syncpt_put(struct host1x_syncpt *sp)
 368 {
 369         if (!sp)
 370                 return;
 371
 372         kref_put(&sp->ref, syncpt_release);
 373 }
 374 EXPORT_SYMBOL(host1x_syncpt_put);
 375
 376 void host1x_syncpt_deinit(struct host1x *host)
 377 {
 378         struct host1x_syncpt *sp = host->syncpt;
 379         unsigned int i;
 380
 381         for (i = 0; i < host->info->nb_pts; i++, sp++)
 382                 kfree(sp->name);
 383 }
 384
 385 /**
 386  * host1x_syncpt_read_max() - read maximum syncpoint value
 387  * @sp: host1x syncpoint
 388  *
 389  * The maximum syncpoint value indicates how many operations there are in
 390  * queue, either in channel or in a software thread.
 391  */
 392 u32 host1x_syncpt_read_max(struct host1x_syncpt *sp)
 393 {
 394         smp_rmb();
 395
 396         return (u32)atomic_read(&sp->max_val);
 397 }
 398 EXPORT_SYMBOL(host1x_syncpt_read_max);
 399
 400 /**
 401  * host1x_syncpt_read_min() - read minimum syncpoint value
 402  * @sp: host1x syncpoint
 403  *
 404  * The minimum syncpoint value is a shadow of the current sync point value in
 405  * hardware.
 406  */
 407 u32 host1x_syncpt_read_min(struct host1x_syncpt *sp)
 408 {
 409         smp_rmb();
 410
 411         return (u32)atomic_read(&sp->min_val);
 412 }
 413 EXPORT_SYMBOL(host1x_syncpt_read_min);
 414
 415 /**
 416  * host1x_syncpt_read() - read the current syncpoint value
 417  * @sp: host1x syncpoint
 418  */
 419 u32 host1x_syncpt_read(struct host1x_syncpt *sp)
 420 {
 421         return host1x_syncpt_load(sp);
 422 }
 423 EXPORT_SYMBOL(host1x_syncpt_read);
 424
 425 unsigned int host1x_syncpt_nb_pts(struct host1x *host)
 426 {
 427         return host->info->nb_pts;
 428 }
 429
 430 unsigned int host1x_syncpt_nb_bases(struct host1x *host)
 431 {
 432         return host->info->nb_bases;
 433 }
 434
 435 unsigned int host1x_syncpt_nb_mlocks(struct host1x *host)
 436 {
 437         return host->info->nb_mlocks;
 438 }
 439
 440 /**
 441  * host1x_syncpt_get_by_id() - obtain a syncpoint by ID
 442  * @host: host1x controller
 443  * @id: syncpoint ID
 444  */
 445 struct host1x_syncpt *host1x_syncpt_get_by_id(struct host1x *host,
 446                                               unsigned int id)
 447 {
 448         if (id >= host->info->nb_pts)
 449                 return NULL;
 450
 451         if (kref_get_unless_zero(&host->syncpt[id].ref))
 452                 return &host->syncpt[id];
 453         else
 454                 return NULL;
 455 }
 456 EXPORT_SYMBOL(host1x_syncpt_get_by_id);
 457
 458 /**
 459  * host1x_syncpt_get_by_id_noref() - obtain a syncpoint by ID but don't
 460  *      increase the refcount.
 461  * @host: host1x controller
 462  * @id: syncpoint ID
 463  */
 464 struct host1x_syncpt *host1x_syncpt_get_by_id_noref(struct host1x *host,
 465                                                     unsigned int id)
 466 {
 467         if (id >= host->info->nb_pts)
 468                 return NULL;
 469
 470         return &host->syncpt[id];
 471 }
 472 EXPORT_SYMBOL(host1x_syncpt_get_by_id_noref);
 473
 474 /**
 475  * host1x_syncpt_get() - increment syncpoint refcount
 476  * @sp: syncpoint
 477  */
 478 struct host1x_syncpt *host1x_syncpt_get(struct host1x_syncpt *sp)
 479 {
 480         kref_get(&sp->ref);
 481
 482         return sp;
 483 }
 484 EXPORT_SYMBOL(host1x_syncpt_get);
 485
 486 /**
 487  * host1x_syncpt_get_base() - obtain the wait base associated with a syncpoint
 488  * @sp: host1x syncpoint
 489  */
 490 struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp)
 491 {
 492         return sp ? sp->base : NULL;
 493 }
 494 EXPORT_SYMBOL(host1x_syncpt_get_base);
 495
 496 /**
 497  * host1x_syncpt_base_id() - retrieve the ID of a syncpoint wait base
 498  * @base: host1x syncpoint wait base
 499  */
 500 u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base)
 501 {
 502         return base->id;
 503 }
 504 EXPORT_SYMBOL(host1x_syncpt_base_id);
 505
 506 static void do_nothing(struct kref *ref)
 507 {
 508 }
 509
 510 /**
 511  * host1x_syncpt_release_vblank_reservation() - Make VBLANK syncpoint
 512  *   available for allocation
 513  *
 514  * @client: host1x bus client
 515  * @syncpt_id: syncpoint ID to make available
 516  *
 517  * Makes VBLANK<i> syncpoint available for allocatation if it was
 518  * reserved at initialization time. This should be called by the display
 519  * driver after it has ensured that any VBLANK increment programming configured
 520  * by the boot chain has been disabled.
 521  */
 522 void host1x_syncpt_release_vblank_reservation(struct host1x_client *client,
 523                                               u32 syncpt_id)
 524 {
 525         struct host1x *host = dev_get_drvdata(client->host->parent);
 526
 527         if (!host->info->reserve_vblank_syncpts)
 528                 return;
 529
 530         kref_put(&host->syncpt[syncpt_id].ref, do_nothing);
 531 }
 532 EXPORT_SYMBOL(host1x_syncpt_release_vblank_reservation);