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