drivers/gpu/host1x/syncpt.c

   1 /*
   2  * Tegra host1x Syncpoints
   3  *
   4  * Copyright (c) 2010-2015, NVIDIA Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/device.h>
  21 #include <linux/slab.h>
  22
  23 #include <trace/events/host1x.h>
  24
  25 #include "syncpt.h"
  26 #include "dev.h"
  27 #include "intr.h"
  28 #include "debug.h"
  29
  30 #define SYNCPT_CHECK_PERIOD (2 * HZ)
  31 #define MAX_STUCK_CHECK_COUNT 15
  32
  33 static struct host1x_syncpt_base *
  34 host1x_syncpt_base_request(struct host1x *host)
  35 {
  36         struct host1x_syncpt_base *bases = host->bases;
  37         unsigned int i;
  38
  39         for (i = 0; i < host->info->nb_bases; i++)
  40                 if (!bases[i].requested)
  41                         break;
  42
  43         if (i >= host->info->nb_bases)
  44                 return NULL;
  45
  46         bases[i].requested = true;
  47         return &bases[i];
  48 }
  49
  50 static void host1x_syncpt_base_free(struct host1x_syncpt_base *base)
  51 {
  52         if (base)
  53                 base->requested = false;
  54 }
  55
  56 static struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host,
  57                                                  struct device *dev,
  58                                                  unsigned long flags)
  59 {
  60         int i;
  61         struct host1x_syncpt *sp = host->syncpt;
  62         char *name;
  63
  64         mutex_lock(&host->syncpt_mutex);
  65
  66         for (i = 0; i < host->info->nb_pts && sp->name; i++, sp++)
  67                 ;
  68
  69         if (i >= host->info->nb_pts)
  70                 goto unlock;
  71
  72         if (flags & HOST1X_SYNCPT_HAS_BASE) {
  73                 sp->base = host1x_syncpt_base_request(host);
  74                 if (!sp->base)
  75                         goto unlock;
  76         }
  77
  78         name = kasprintf(GFP_KERNEL, "%02u-%s", sp->id,
  79                         dev ? dev_name(dev) : NULL);
  80         if (!name)
  81                 goto free_base;
  82
  83         sp->dev = dev;
  84         sp->name = name;
  85
  86         if (flags & HOST1X_SYNCPT_CLIENT_MANAGED)
  87                 sp->client_managed = true;
  88         else
  89                 sp->client_managed = false;
  90
  91         mutex_unlock(&host->syncpt_mutex);
  92         return sp;
  93
  94 free_base:
  95         host1x_syncpt_base_free(sp->base);
  96         sp->base = NULL;
  97 unlock:
  98         mutex_unlock(&host->syncpt_mutex);
  99         return NULL;
 100 }
 101
 102 u32 host1x_syncpt_id(struct host1x_syncpt *sp)
 103 {
 104         return sp->id;
 105 }
 106 EXPORT_SYMBOL(host1x_syncpt_id);
 107
 108 /*
 109  * Updates the value sent to hardware.
 110  */
 111 u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs)
 112 {
 113         return (u32)atomic_add_return(incrs, &sp->max_val);
 114 }
 115 EXPORT_SYMBOL(host1x_syncpt_incr_max);
 116
 117  /*
 118  * Write cached syncpoint and waitbase values to hardware.
 119  */
 120 void host1x_syncpt_restore(struct host1x *host)
 121 {
 122         struct host1x_syncpt *sp_base = host->syncpt;
 123         unsigned int i;
 124
 125         for (i = 0; i < host1x_syncpt_nb_pts(host); i++)
 126                 host1x_hw_syncpt_restore(host, sp_base + i);
 127
 128         for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
 129                 host1x_hw_syncpt_restore_wait_base(host, sp_base + i);
 130
 131         wmb();
 132 }
 133
 134 /*
 135  * Update the cached syncpoint and waitbase values by reading them
 136  * from the registers.
 137   */
 138 void host1x_syncpt_save(struct host1x *host)
 139 {
 140         struct host1x_syncpt *sp_base = host->syncpt;
 141         unsigned int i;
 142
 143         for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
 144                 if (host1x_syncpt_client_managed(sp_base + i))
 145                         host1x_hw_syncpt_load(host, sp_base + i);
 146                 else
 147                         WARN_ON(!host1x_syncpt_idle(sp_base + i));
 148         }
 149
 150         for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
 151                 host1x_hw_syncpt_load_wait_base(host, sp_base + i);
 152 }
 153
 154 /*
 155  * Updates the cached syncpoint value by reading a new value from the hardware
 156  * register
 157  */
 158 u32 host1x_syncpt_load(struct host1x_syncpt *sp)
 159 {
 160         u32 val;
 161
 162         val = host1x_hw_syncpt_load(sp->host, sp);
 163         trace_host1x_syncpt_load_min(sp->id, val);
 164
 165         return val;
 166 }
 167
 168 /*
 169  * Get the current syncpoint base
 170  */
 171 u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp)
 172 {
 173         host1x_hw_syncpt_load_wait_base(sp->host, sp);
 174
 175         return sp->base_val;
 176 }
 177
 178 /*
 179  * Increment syncpoint value from cpu, updating cache
 180  */
 181 int host1x_syncpt_incr(struct host1x_syncpt *sp)
 182 {
 183         return host1x_hw_syncpt_cpu_incr(sp->host, sp);
 184 }
 185 EXPORT_SYMBOL(host1x_syncpt_incr);
 186
 187 /*
 188  * Updated sync point form hardware, and returns true if syncpoint is expired,
 189  * false if we may need to wait
 190  */
 191 static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh)
 192 {
 193         host1x_hw_syncpt_load(sp->host, sp);
 194
 195         return host1x_syncpt_is_expired(sp, thresh);
 196 }
 197
 198 /*
 199  * Main entrypoint for syncpoint value waits.
 200  */
 201 int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
 202                        u32 *value)
 203 {
 204         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
 205         void *ref;
 206         struct host1x_waitlist *waiter;
 207         int err = 0, check_count = 0;
 208         u32 val;
 209
 210         if (value)
 211                 *value = 0;
 212
 213         /* first check cache */
 214         if (host1x_syncpt_is_expired(sp, thresh)) {
 215                 if (value)
 216                         *value = host1x_syncpt_load(sp);
 217
 218                 return 0;
 219         }
 220
 221         /* try to read from register */
 222         val = host1x_hw_syncpt_load(sp->host, sp);
 223         if (host1x_syncpt_is_expired(sp, thresh)) {
 224                 if (value)
 225                         *value = val;
 226
 227                 goto done;
 228         }
 229
 230         if (!timeout) {
 231                 err = -EAGAIN;
 232                 goto done;
 233         }
 234
 235         /* allocate a waiter */
 236         waiter = kzalloc(sizeof(*waiter), GFP_KERNEL);
 237         if (!waiter) {
 238                 err = -ENOMEM;
 239                 goto done;
 240         }
 241
 242         /* schedule a wakeup when the syncpoint value is reached */
 243         err = host1x_intr_add_action(sp->host, sp->id, thresh,
 244                                      HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE,
 245                                      &wq, waiter, &ref);
 246         if (err)
 247                 goto done;
 248
 249         err = -EAGAIN;
 250         /* Caller-specified timeout may be impractically low */
 251         if (timeout < 0)
 252                 timeout = LONG_MAX;
 253
 254         /* wait for the syncpoint, or timeout, or signal */
 255         while (timeout) {
 256                 long check = min_t(long, SYNCPT_CHECK_PERIOD, timeout);
 257                 int remain;
 258
 259                 remain = wait_event_interruptible_timeout(wq,
 260                                 syncpt_load_min_is_expired(sp, thresh),
 261                                 check);
 262                 if (remain > 0 || host1x_syncpt_is_expired(sp, thresh)) {
 263                         if (value)
 264                                 *value = host1x_syncpt_load(sp);
 265
 266                         err = 0;
 267
 268                         break;
 269                 }
 270
 271                 if (remain < 0) {
 272                         err = remain;
 273                         break;
 274                 }
 275
 276                 timeout -= check;
 277
 278                 if (timeout && check_count <= MAX_STUCK_CHECK_COUNT) {
 279                         dev_warn(sp->host->dev,
 280                                 "%s: syncpoint id %u (%s) stuck waiting %d, timeout=%ld\n",
 281                                  current->comm, sp->id, sp->name,
 282                                  thresh, timeout);
 283
 284                         host1x_debug_dump_syncpts(sp->host);
 285
 286                         if (check_count == MAX_STUCK_CHECK_COUNT)
 287                                 host1x_debug_dump(sp->host);
 288
 289                         check_count++;
 290                 }
 291         }
 292
 293         host1x_intr_put_ref(sp->host, sp->id, ref);
 294
 295 done:
 296         return err;
 297 }
 298 EXPORT_SYMBOL(host1x_syncpt_wait);
 299
 300 /*
 301  * Returns true if syncpoint is expired, false if we may need to wait
 302  */
 303 bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh)
 304 {
 305         u32 current_val;
 306         u32 future_val;
 307
 308         smp_rmb();
 309
 310         current_val = (u32)atomic_read(&sp->min_val);
 311         future_val = (u32)atomic_read(&sp->max_val);
 312
 313         /* Note the use of unsigned arithmetic here (mod 1<<32).
 314          *
 315          * c = current_val = min_val    = the current value of the syncpoint.
 316          * t = thresh                   = the value we are checking
 317          * f = future_val  = max_val    = the value c will reach when all
 318          *                                outstanding increments have completed.
 319          *
 320          * Note that c always chases f until it reaches f.
 321          *
 322          * Dtf = (f - t)
 323          * Dtc = (c - t)
 324          *
 325          *  Consider all cases:
 326          *
 327          *      A) .....c..t..f.....    Dtf < Dtc       need to wait
 328          *      B) .....c.....f..t..    Dtf > Dtc       expired
 329          *      C) ..t..c.....f.....    Dtf > Dtc       expired    (Dct very large)
 330          *
 331          *  Any case where f==c: always expired (for any t).    Dtf == Dcf
 332          *  Any case where t==c: always expired (for any f).    Dtf >= Dtc (because Dtc==0)
 333          *  Any case where t==f!=c: always wait.                Dtf <  Dtc (because Dtf==0,
 334          *                                                      Dtc!=0)
 335          *
 336          *  Other cases:
 337          *
 338          *      A) .....t..f..c.....    Dtf < Dtc       need to wait
 339          *      A) .....f..c..t.....    Dtf < Dtc       need to wait
 340          *      A) .....f..t..c.....    Dtf > Dtc       expired
 341          *
 342          *   So:
 343          *         Dtf >= Dtc implies EXPIRED   (return true)
 344          *         Dtf <  Dtc implies WAIT      (return false)
 345          *
 346          * Note: If t is expired then we *cannot* wait on it. We would wait
 347          * forever (hang the system).
 348          *
 349          * Note: do NOT get clever and remove the -thresh from both sides. It
 350          * is NOT the same.
 351          *
 352          * If future valueis zero, we have a client managed sync point. In that
 353          * case we do a direct comparison.
 354          */
 355         if (!host1x_syncpt_client_managed(sp))
 356                 return future_val - thresh >= current_val - thresh;
 357         else
 358                 return (s32)(current_val - thresh) >= 0;
 359 }
 360
 361 /* remove a wait pointed to by patch_addr */
 362 int host1x_syncpt_patch_wait(struct host1x_syncpt *sp, void *patch_addr)
 363 {
 364         return host1x_hw_syncpt_patch_wait(sp->host, sp, patch_addr);
 365 }
 366
 367 int host1x_syncpt_init(struct host1x *host)
 368 {
 369         struct host1x_syncpt_base *bases;
 370         struct host1x_syncpt *syncpt;
 371         unsigned int i;
 372
 373         syncpt = devm_kcalloc(host->dev, host->info->nb_pts, sizeof(*syncpt),
 374                               GFP_KERNEL);
 375         if (!syncpt)
 376                 return -ENOMEM;
 377
 378         bases = devm_kcalloc(host->dev, host->info->nb_bases, sizeof(*bases),
 379                              GFP_KERNEL);
 380         if (!bases)
 381                 return -ENOMEM;
 382
 383         for (i = 0; i < host->info->nb_pts; i++) {
 384                 syncpt[i].id = i;
 385                 syncpt[i].host = host;
 386         }
 387
 388         for (i = 0; i < host->info->nb_bases; i++)
 389                 bases[i].id = i;
 390
 391         mutex_init(&host->syncpt_mutex);
 392         host->syncpt = syncpt;
 393         host->bases = bases;
 394
 395         host1x_syncpt_restore(host);
 396
 397         /* Allocate sync point to use for clearing waits for expired fences */
 398         host->nop_sp = host1x_syncpt_alloc(host, NULL, 0);
 399         if (!host->nop_sp)
 400                 return -ENOMEM;
 401
 402         return 0;
 403 }
 404
 405 struct host1x_syncpt *host1x_syncpt_request(struct device *dev,
 406                                             unsigned long flags)
 407 {
 408         struct host1x *host = dev_get_drvdata(dev->parent);
 409
 410         return host1x_syncpt_alloc(host, dev, flags);
 411 }
 412 EXPORT_SYMBOL(host1x_syncpt_request);
 413
 414 void host1x_syncpt_free(struct host1x_syncpt *sp)
 415 {
 416         if (!sp)
 417                 return;
 418
 419         mutex_lock(&sp->host->syncpt_mutex);
 420
 421         host1x_syncpt_base_free(sp->base);
 422         kfree(sp->name);
 423         sp->base = NULL;
 424         sp->dev = NULL;
 425         sp->name = NULL;
 426         sp->client_managed = false;
 427
 428         mutex_unlock(&sp->host->syncpt_mutex);
 429 }
 430 EXPORT_SYMBOL(host1x_syncpt_free);
 431
 432 void host1x_syncpt_deinit(struct host1x *host)
 433 {
 434         struct host1x_syncpt *sp = host->syncpt;
 435         unsigned int i;
 436
 437         for (i = 0; i < host->info->nb_pts; i++, sp++)
 438                 kfree(sp->name);
 439 }
 440
 441 /*
 442  * Read max. It indicates how many operations there are in queue, either in
 443  * channel or in a software thread.
 444  */
 445 u32 host1x_syncpt_read_max(struct host1x_syncpt *sp)
 446 {
 447         smp_rmb();
 448
 449         return (u32)atomic_read(&sp->max_val);
 450 }
 451 EXPORT_SYMBOL(host1x_syncpt_read_max);
 452
 453 /*
 454  * Read min, which is a shadow of the current sync point value in hardware.
 455  */
 456 u32 host1x_syncpt_read_min(struct host1x_syncpt *sp)
 457 {
 458         smp_rmb();
 459
 460         return (u32)atomic_read(&sp->min_val);
 461 }
 462 EXPORT_SYMBOL(host1x_syncpt_read_min);
 463
 464 u32 host1x_syncpt_read(struct host1x_syncpt *sp)
 465 {
 466         return host1x_syncpt_load(sp);
 467 }
 468 EXPORT_SYMBOL(host1x_syncpt_read);
 469
 470 unsigned int host1x_syncpt_nb_pts(struct host1x *host)
 471 {
 472         return host->info->nb_pts;
 473 }
 474
 475 unsigned int host1x_syncpt_nb_bases(struct host1x *host)
 476 {
 477         return host->info->nb_bases;
 478 }
 479
 480 unsigned int host1x_syncpt_nb_mlocks(struct host1x *host)
 481 {
 482         return host->info->nb_mlocks;
 483 }
 484
 485 struct host1x_syncpt *host1x_syncpt_get(struct host1x *host, unsigned int id)
 486 {
 487         if (host->info->nb_pts < id)
 488                 return NULL;
 489
 490         return host->syncpt + id;
 491 }
 492 EXPORT_SYMBOL(host1x_syncpt_get);
 493
 494 struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp)
 495 {
 496         return sp ? sp->base : NULL;
 497 }
 498 EXPORT_SYMBOL(host1x_syncpt_get_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);