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 u32 host1x_syncpt_read(struct host1x_syncpt *sp) 429 { 430 return host1x_syncpt_load(sp); 431 } 432 EXPORT_SYMBOL(host1x_syncpt_read); 433 434 int host1x_syncpt_nb_pts(struct host1x *host) 435 { 436 return host->info->nb_pts; 437 } 438 439 int host1x_syncpt_nb_bases(struct host1x *host) 440 { 441 return host->info->nb_bases; 442 } 443 444 int host1x_syncpt_nb_mlocks(struct host1x *host) 445 { 446 return host->info->nb_mlocks; 447 } 448 449 struct host1x_syncpt *host1x_syncpt_get(struct host1x *host, u32 id) 450 { 451 if (host->info->nb_pts < id) 452 return NULL; 453 return host->syncpt + id; 454 } 455 EXPORT_SYMBOL(host1x_syncpt_get); 456 457 struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp) 458 { 459 return sp ? sp->base : NULL; 460 } 461 EXPORT_SYMBOL(host1x_syncpt_get_base); 462 463 u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base) 464 { 465 return base->id; 466 } 467 EXPORT_SYMBOL(host1x_syncpt_base_id); 468