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