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