drivers/gpu/host1x/syncpt.c

   1 /*
   2  * Tegra host1x Syncpoints
   3  *
   4  * Copyright (c) 2010-2013, 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         for (i = 0; i < host->info->nb_pts && sp->name; i++, sp++)
  65                 ;
  66
  67         if (i >= host->info->nb_pts)
  68                 return NULL;
  69
  70         if (flags & HOST1X_SYNCPT_HAS_BASE) {
  71                 sp->base = host1x_syncpt_base_request(host);
  72                 if (!sp->base)
  73                         return NULL;
  74         }
  75
  76         name = kasprintf(GFP_KERNEL, "%02u-%s", sp->id,
  77                         dev ? dev_name(dev) : NULL);
  78         if (!name)
  79                 return NULL;
  80
  81         sp->dev = dev;
  82         sp->name = name;
  83
  84         if (flags & HOST1X_SYNCPT_CLIENT_MANAGED)
  85                 sp->client_managed = true;
  86         else
  87                 sp->client_managed = false;
  88
  89         return sp;
  90 }
  91
  92 u32 host1x_syncpt_id(struct host1x_syncpt *sp)
  93 {
  94         return sp->id;
  95 }
  96 EXPORT_SYMBOL(host1x_syncpt_id);
  97
  98 /*
  99  * Updates the value sent to hardware.
 100  */
 101 u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs)
 102 {
 103         return (u32)atomic_add_return(incrs, &sp->max_val);
 104 }
 105 EXPORT_SYMBOL(host1x_syncpt_incr_max);
 106
 107  /*
 108  * Write cached syncpoint and waitbase values to hardware.
 109  */
 110 void host1x_syncpt_restore(struct host1x *host)
 111 {
 112         struct host1x_syncpt *sp_base = host->syncpt;
 113         unsigned int i;
 114
 115         for (i = 0; i < host1x_syncpt_nb_pts(host); i++)
 116                 host1x_hw_syncpt_restore(host, sp_base + i);
 117
 118         for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
 119                 host1x_hw_syncpt_restore_wait_base(host, sp_base + i);
 120
 121         wmb();
 122 }
 123
 124 /*
 125  * Update the cached syncpoint and waitbase values by reading them
 126  * from the registers.
 127   */
 128 void host1x_syncpt_save(struct host1x *host)
 129 {
 130         struct host1x_syncpt *sp_base = host->syncpt;
 131         unsigned int i;
 132
 133         for (i = 0; i < host1x_syncpt_nb_pts(host); i++) {
 134                 if (host1x_syncpt_client_managed(sp_base + i))
 135                         host1x_hw_syncpt_load(host, sp_base + i);
 136                 else
 137                         WARN_ON(!host1x_syncpt_idle(sp_base + i));
 138         }
 139
 140         for (i = 0; i < host1x_syncpt_nb_bases(host); i++)
 141                 host1x_hw_syncpt_load_wait_base(host, sp_base + i);
 142 }
 143
 144 /*
 145  * Updates the cached syncpoint value by reading a new value from the hardware
 146  * register
 147  */
 148 u32 host1x_syncpt_load(struct host1x_syncpt *sp)
 149 {
 150         u32 val;
 151
 152         val = host1x_hw_syncpt_load(sp->host, sp);
 153         trace_host1x_syncpt_load_min(sp->id, val);
 154
 155         return val;
 156 }
 157
 158 /*
 159  * Get the current syncpoint base
 160  */
 161 u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp)
 162 {
 163         host1x_hw_syncpt_load_wait_base(sp->host, sp);
 164
 165         return sp->base_val;
 166 }
 167
 168 /*
 169  * Increment syncpoint value from cpu, updating cache
 170  */
 171 int host1x_syncpt_incr(struct host1x_syncpt *sp)
 172 {
 173         return host1x_hw_syncpt_cpu_incr(sp->host, sp);
 174 }
 175 EXPORT_SYMBOL(host1x_syncpt_incr);
 176
 177 /*
 178  * Updated sync point form hardware, and returns true if syncpoint is expired,
 179  * false if we may need to wait
 180  */
 181 static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh)
 182 {
 183         host1x_hw_syncpt_load(sp->host, sp);
 184
 185         return host1x_syncpt_is_expired(sp, thresh);
 186 }
 187
 188 /*
 189  * Main entrypoint for syncpoint value waits.
 190  */
 191 int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout,
 192                        u32 *value)
 193 {
 194         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
 195         void *ref;
 196         struct host1x_waitlist *waiter;
 197         int err = 0, check_count = 0;
 198         u32 val;
 199
 200         if (value)
 201                 *value = 0;
 202
 203         /* first check cache */
 204         if (host1x_syncpt_is_expired(sp, thresh)) {
 205                 if (value)
 206                         *value = host1x_syncpt_load(sp);
 207
 208                 return 0;
 209         }
 210
 211         /* try to read from register */
 212         val = host1x_hw_syncpt_load(sp->host, sp);
 213         if (host1x_syncpt_is_expired(sp, thresh)) {
 214                 if (value)
 215                         *value = val;
 216
 217                 goto done;
 218         }
 219
 220         if (!timeout) {
 221                 err = -EAGAIN;
 222                 goto done;
 223         }
 224
 225         /* allocate a waiter */
 226         waiter = kzalloc(sizeof(*waiter), GFP_KERNEL);
 227         if (!waiter) {
 228                 err = -ENOMEM;
 229                 goto done;
 230         }
 231
 232         /* schedule a wakeup when the syncpoint value is reached */
 233         err = host1x_intr_add_action(sp->host, sp->id, thresh,
 234                                      HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE,
 235                                      &wq, waiter, &ref);
 236         if (err)
 237                 goto done;
 238
 239         err = -EAGAIN;
 240         /* Caller-specified timeout may be impractically low */
 241         if (timeout < 0)
 242                 timeout = LONG_MAX;
 243
 244         /* wait for the syncpoint, or timeout, or signal */
 245         while (timeout) {
 246                 long check = min_t(long, SYNCPT_CHECK_PERIOD, timeout);
 247                 int remain;
 248
 249                 remain = wait_event_interruptible_timeout(wq,
 250                                 syncpt_load_min_is_expired(sp, thresh),
 251                                 check);
 252                 if (remain > 0 || host1x_syncpt_is_expired(sp, thresh)) {
 253                         if (value)
 254                                 *value = host1x_syncpt_load(sp);
 255
 256                         err = 0;
 257
 258                         break;
 259                 }
 260
 261                 if (remain < 0) {
 262                         err = remain;
 263                         break;
 264                 }
 265
 266                 timeout -= check;
 267
 268                 if (timeout && check_count <= MAX_STUCK_CHECK_COUNT) {
 269                         dev_warn(sp->host->dev,
 270                                 "%s: syncpoint id %u (%s) stuck waiting %d, timeout=%ld\n",
 271                                  current->comm, sp->id, sp->name,
 272                                  thresh, timeout);
 273
 274                         host1x_debug_dump_syncpts(sp->host);
 275
 276                         if (check_count == MAX_STUCK_CHECK_COUNT)
 277                                 host1x_debug_dump(sp->host);
 278
 279                         check_count++;
 280                 }
 281         }
 282
 283         host1x_intr_put_ref(sp->host, sp->id, ref);
 284
 285 done:
 286         return err;
 287 }
 288 EXPORT_SYMBOL(host1x_syncpt_wait);
 289
 290 /*
 291  * Returns true if syncpoint is expired, false if we may need to wait
 292  */
 293 bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh)
 294 {
 295         u32 current_val;
 296         u32 future_val;
 297
 298         smp_rmb();
 299
 300         current_val = (u32)atomic_read(&sp->min_val);
 301         future_val = (u32)atomic_read(&sp->max_val);
 302
 303         /* Note the use of unsigned arithmetic here (mod 1<<32).
 304          *
 305          * c = current_val = min_val    = the current value of the syncpoint.
 306          * t = thresh                   = the value we are checking
 307          * f = future_val  = max_val    = the value c will reach when all
 308          *                                outstanding increments have completed.
 309          *
 310          * Note that c always chases f until it reaches f.
 311          *
 312          * Dtf = (f - t)
 313          * Dtc = (c - t)
 314          *
 315          *  Consider all cases:
 316          *
 317          *      A) .....c..t..f.....    Dtf < Dtc       need to wait
 318          *      B) .....c.....f..t..    Dtf > Dtc       expired
 319          *      C) ..t..c.....f.....    Dtf > Dtc       expired    (Dct very large)
 320          *
 321          *  Any case where f==c: always expired (for any t).    Dtf == Dcf
 322          *  Any case where t==c: always expired (for any f).    Dtf >= Dtc (because Dtc==0)
 323          *  Any case where t==f!=c: always wait.                Dtf <  Dtc (because Dtf==0,
 324          *                                                      Dtc!=0)
 325          *
 326          *  Other cases:
 327          *
 328          *      A) .....t..f..c.....    Dtf < Dtc       need to wait
 329          *      A) .....f..c..t.....    Dtf < Dtc       need to wait
 330          *      A) .....f..t..c.....    Dtf > Dtc       expired
 331          *
 332          *   So:
 333          *         Dtf >= Dtc implies EXPIRED   (return true)
 334          *         Dtf <  Dtc implies WAIT      (return false)
 335          *
 336          * Note: If t is expired then we *cannot* wait on it. We would wait
 337          * forever (hang the system).
 338          *
 339          * Note: do NOT get clever and remove the -thresh from both sides. It
 340          * is NOT the same.
 341          *
 342          * If future valueis zero, we have a client managed sync point. In that
 343          * case we do a direct comparison.
 344          */
 345         if (!host1x_syncpt_client_managed(sp))
 346                 return future_val - thresh >= current_val - thresh;
 347         else
 348                 return (s32)(current_val - thresh) >= 0;
 349 }
 350
 351 /* remove a wait pointed to by patch_addr */
 352 int host1x_syncpt_patch_wait(struct host1x_syncpt *sp, void *patch_addr)
 353 {
 354         return host1x_hw_syncpt_patch_wait(sp->host, sp, patch_addr);
 355 }
 356
 357 int host1x_syncpt_init(struct host1x *host)
 358 {
 359         struct host1x_syncpt_base *bases;
 360         struct host1x_syncpt *syncpt;
 361         unsigned int i;
 362
 363         syncpt = devm_kcalloc(host->dev, host->info->nb_pts, sizeof(*syncpt),
 364                               GFP_KERNEL);
 365         if (!syncpt)
 366                 return -ENOMEM;
 367
 368         bases = devm_kcalloc(host->dev, host->info->nb_bases, sizeof(*bases),
 369                              GFP_KERNEL);
 370         if (!bases)
 371                 return -ENOMEM;
 372
 373         for (i = 0; i < host->info->nb_pts; i++) {
 374                 syncpt[i].id = i;
 375                 syncpt[i].host = host;
 376         }
 377
 378         for (i = 0; i < host->info->nb_bases; i++)
 379                 bases[i].id = i;
 380
 381         host->syncpt = syncpt;
 382         host->bases = bases;
 383
 384         host1x_syncpt_restore(host);
 385
 386         /* Allocate sync point to use for clearing waits for expired fences */
 387         host->nop_sp = host1x_syncpt_alloc(host, NULL, 0);
 388         if (!host->nop_sp)
 389                 return -ENOMEM;
 390
 391         return 0;
 392 }
 393
 394 struct host1x_syncpt *host1x_syncpt_request(struct device *dev,
 395                                             unsigned long flags)
 396 {
 397         struct host1x *host = dev_get_drvdata(dev->parent);
 398
 399         return host1x_syncpt_alloc(host, dev, flags);
 400 }
 401 EXPORT_SYMBOL(host1x_syncpt_request);
 402
 403 void host1x_syncpt_free(struct host1x_syncpt *sp)
 404 {
 405         if (!sp)
 406                 return;
 407
 408         host1x_syncpt_base_free(sp->base);
 409         kfree(sp->name);
 410         sp->base = NULL;
 411         sp->dev = NULL;
 412         sp->name = NULL;
 413         sp->client_managed = false;
 414 }
 415 EXPORT_SYMBOL(host1x_syncpt_free);
 416
 417 void host1x_syncpt_deinit(struct host1x *host)
 418 {
 419         struct host1x_syncpt *sp = host->syncpt;
 420         unsigned int i;
 421
 422         for (i = 0; i < host->info->nb_pts; i++, sp++)
 423                 kfree(sp->name);
 424 }
 425
 426 /*
 427  * Read max. It indicates how many operations there are in queue, either in
 428  * channel or in a software thread.
 429  */
 430 u32 host1x_syncpt_read_max(struct host1x_syncpt *sp)
 431 {
 432         smp_rmb();
 433
 434         return (u32)atomic_read(&sp->max_val);
 435 }
 436 EXPORT_SYMBOL(host1x_syncpt_read_max);
 437
 438 /*
 439  * Read min, which is a shadow of the current sync point value in hardware.
 440  */
 441 u32 host1x_syncpt_read_min(struct host1x_syncpt *sp)
 442 {
 443         smp_rmb();
 444
 445         return (u32)atomic_read(&sp->min_val);
 446 }
 447 EXPORT_SYMBOL(host1x_syncpt_read_min);
 448
 449 u32 host1x_syncpt_read(struct host1x_syncpt *sp)
 450 {
 451         return host1x_syncpt_load(sp);
 452 }
 453 EXPORT_SYMBOL(host1x_syncpt_read);
 454
 455 unsigned int host1x_syncpt_nb_pts(struct host1x *host)
 456 {
 457         return host->info->nb_pts;
 458 }
 459
 460 unsigned int host1x_syncpt_nb_bases(struct host1x *host)
 461 {
 462         return host->info->nb_bases;
 463 }
 464
 465 unsigned int host1x_syncpt_nb_mlocks(struct host1x *host)
 466 {
 467         return host->info->nb_mlocks;
 468 }
 469
 470 struct host1x_syncpt *host1x_syncpt_get(struct host1x *host, unsigned int id)
 471 {
 472         if (host->info->nb_pts < id)
 473                 return NULL;
 474
 475         return host->syncpt + id;
 476 }
 477 EXPORT_SYMBOL(host1x_syncpt_get);
 478
 479 struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp)
 480 {
 481         return sp ? sp->base : NULL;
 482 }
 483 EXPORT_SYMBOL(host1x_syncpt_get_base);
 484
 485 u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base)
 486 {
 487         return base->id;
 488 }
 489 EXPORT_SYMBOL(host1x_syncpt_base_id);