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 *_host1x_syncpt_alloc(struct host1x *host, 34 struct device *dev, 35 bool client_managed) 36 { 37 int i; 38 struct host1x_syncpt *sp = host->syncpt; 39 char *name; 40 41 for (i = 0; i < host->info->nb_pts && sp->name; i++, sp++) 42 ; 43 44 if (i >= host->info->nb_pts) 45 return NULL; 46 47 name = kasprintf(GFP_KERNEL, "%02d-%s", sp->id, 48 dev ? dev_name(dev) : NULL); 49 if (!name) 50 return NULL; 51 52 sp->dev = dev; 53 sp->name = name; 54 sp->client_managed = client_managed; 55 56 return sp; 57 } 58 59 u32 host1x_syncpt_id(struct host1x_syncpt *sp) 60 { 61 return sp->id; 62 } 63 64 /* 65 * Updates the value sent to hardware. 66 */ 67 u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs) 68 { 69 return (u32)atomic_add_return(incrs, &sp->max_val); 70 } 71 72 /* 73 * Write cached syncpoint and waitbase values to hardware. 74 */ 75 void host1x_syncpt_restore(struct host1x *host) 76 { 77 struct host1x_syncpt *sp_base = host->syncpt; 78 u32 i; 79 80 for (i = 0; i < host1x_syncpt_nb_pts(host); i++) 81 host1x_hw_syncpt_restore(host, sp_base + i); 82 for (i = 0; i < host1x_syncpt_nb_bases(host); i++) 83 host1x_hw_syncpt_restore_wait_base(host, sp_base + i); 84 wmb(); 85 } 86 87 /* 88 * Update the cached syncpoint and waitbase values by reading them 89 * from the registers. 90 */ 91 void host1x_syncpt_save(struct host1x *host) 92 { 93 struct host1x_syncpt *sp_base = host->syncpt; 94 u32 i; 95 96 for (i = 0; i < host1x_syncpt_nb_pts(host); i++) { 97 if (host1x_syncpt_client_managed(sp_base + i)) 98 host1x_hw_syncpt_load(host, sp_base + i); 99 else 100 WARN_ON(!host1x_syncpt_idle(sp_base + i)); 101 } 102 103 for (i = 0; i < host1x_syncpt_nb_bases(host); i++) 104 host1x_hw_syncpt_load_wait_base(host, sp_base + i); 105 } 106 107 /* 108 * Updates the cached syncpoint value by reading a new value from the hardware 109 * register 110 */ 111 u32 host1x_syncpt_load(struct host1x_syncpt *sp) 112 { 113 u32 val; 114 val = host1x_hw_syncpt_load(sp->host, sp); 115 trace_host1x_syncpt_load_min(sp->id, val); 116 117 return val; 118 } 119 120 /* 121 * Get the current syncpoint base 122 */ 123 u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp) 124 { 125 u32 val; 126 host1x_hw_syncpt_load_wait_base(sp->host, sp); 127 val = sp->base_val; 128 return val; 129 } 130 131 /* 132 * Increment syncpoint value from cpu, updating cache 133 */ 134 int host1x_syncpt_incr(struct host1x_syncpt *sp) 135 { 136 return host1x_hw_syncpt_cpu_incr(sp->host, sp); 137 } 138 139 /* 140 * Updated sync point form hardware, and returns true if syncpoint is expired, 141 * false if we may need to wait 142 */ 143 static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh) 144 { 145 host1x_hw_syncpt_load(sp->host, sp); 146 return host1x_syncpt_is_expired(sp, thresh); 147 } 148 149 /* 150 * Main entrypoint for syncpoint value waits. 151 */ 152 int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout, 153 u32 *value) 154 { 155 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); 156 void *ref; 157 struct host1x_waitlist *waiter; 158 int err = 0, check_count = 0; 159 u32 val; 160 161 if (value) 162 *value = 0; 163 164 /* first check cache */ 165 if (host1x_syncpt_is_expired(sp, thresh)) { 166 if (value) 167 *value = host1x_syncpt_load(sp); 168 return 0; 169 } 170 171 /* try to read from register */ 172 val = host1x_hw_syncpt_load(sp->host, sp); 173 if (host1x_syncpt_is_expired(sp, thresh)) { 174 if (value) 175 *value = val; 176 goto done; 177 } 178 179 if (!timeout) { 180 err = -EAGAIN; 181 goto done; 182 } 183 184 /* allocate a waiter */ 185 waiter = kzalloc(sizeof(*waiter), GFP_KERNEL); 186 if (!waiter) { 187 err = -ENOMEM; 188 goto done; 189 } 190 191 /* schedule a wakeup when the syncpoint value is reached */ 192 err = host1x_intr_add_action(sp->host, sp->id, thresh, 193 HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE, 194 &wq, waiter, &ref); 195 if (err) 196 goto done; 197 198 err = -EAGAIN; 199 /* Caller-specified timeout may be impractically low */ 200 if (timeout < 0) 201 timeout = LONG_MAX; 202 203 /* wait for the syncpoint, or timeout, or signal */ 204 while (timeout) { 205 long check = min_t(long, SYNCPT_CHECK_PERIOD, timeout); 206 int remain = wait_event_interruptible_timeout(wq, 207 syncpt_load_min_is_expired(sp, thresh), 208 check); 209 if (remain > 0 || host1x_syncpt_is_expired(sp, thresh)) { 210 if (value) 211 *value = host1x_syncpt_load(sp); 212 err = 0; 213 break; 214 } 215 if (remain < 0) { 216 err = remain; 217 break; 218 } 219 timeout -= check; 220 if (timeout && check_count <= MAX_STUCK_CHECK_COUNT) { 221 dev_warn(sp->host->dev, 222 "%s: syncpoint id %d (%s) stuck waiting %d, timeout=%ld\n", 223 current->comm, sp->id, sp->name, 224 thresh, timeout); 225 226 host1x_debug_dump_syncpts(sp->host); 227 if (check_count == MAX_STUCK_CHECK_COUNT) 228 host1x_debug_dump(sp->host); 229 check_count++; 230 } 231 } 232 host1x_intr_put_ref(sp->host, sp->id, ref); 233 234 done: 235 return err; 236 } 237 EXPORT_SYMBOL(host1x_syncpt_wait); 238 239 /* 240 * Returns true if syncpoint is expired, false if we may need to wait 241 */ 242 bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh) 243 { 244 u32 current_val; 245 u32 future_val; 246 smp_rmb(); 247 current_val = (u32)atomic_read(&sp->min_val); 248 future_val = (u32)atomic_read(&sp->max_val); 249 250 /* Note the use of unsigned arithmetic here (mod 1<<32). 251 * 252 * c = current_val = min_val = the current value of the syncpoint. 253 * t = thresh = the value we are checking 254 * f = future_val = max_val = the value c will reach when all 255 * outstanding increments have completed. 256 * 257 * Note that c always chases f until it reaches f. 258 * 259 * Dtf = (f - t) 260 * Dtc = (c - t) 261 * 262 * Consider all cases: 263 * 264 * A) .....c..t..f..... Dtf < Dtc need to wait 265 * B) .....c.....f..t.. Dtf > Dtc expired 266 * C) ..t..c.....f..... Dtf > Dtc expired (Dct very large) 267 * 268 * Any case where f==c: always expired (for any t). Dtf == Dcf 269 * Any case where t==c: always expired (for any f). Dtf >= Dtc (because Dtc==0) 270 * Any case where t==f!=c: always wait. Dtf < Dtc (because Dtf==0, 271 * Dtc!=0) 272 * 273 * Other cases: 274 * 275 * A) .....t..f..c..... Dtf < Dtc need to wait 276 * A) .....f..c..t..... Dtf < Dtc need to wait 277 * A) .....f..t..c..... Dtf > Dtc expired 278 * 279 * So: 280 * Dtf >= Dtc implies EXPIRED (return true) 281 * Dtf < Dtc implies WAIT (return false) 282 * 283 * Note: If t is expired then we *cannot* wait on it. We would wait 284 * forever (hang the system). 285 * 286 * Note: do NOT get clever and remove the -thresh from both sides. It 287 * is NOT the same. 288 * 289 * If future valueis zero, we have a client managed sync point. In that 290 * case we do a direct comparison. 291 */ 292 if (!host1x_syncpt_client_managed(sp)) 293 return future_val - thresh >= current_val - thresh; 294 else 295 return (s32)(current_val - thresh) >= 0; 296 } 297 298 /* remove a wait pointed to by patch_addr */ 299 int host1x_syncpt_patch_wait(struct host1x_syncpt *sp, void *patch_addr) 300 { 301 return host1x_hw_syncpt_patch_wait(sp->host, sp, patch_addr); 302 } 303 304 int host1x_syncpt_init(struct host1x *host) 305 { 306 struct host1x_syncpt *syncpt; 307 int i; 308 309 syncpt = devm_kzalloc(host->dev, sizeof(*syncpt) * host->info->nb_pts, 310 GFP_KERNEL); 311 if (!syncpt) 312 return -ENOMEM; 313 314 for (i = 0; i < host->info->nb_pts; ++i) { 315 syncpt[i].id = i; 316 syncpt[i].host = host; 317 } 318 319 host->syncpt = syncpt; 320 321 host1x_syncpt_restore(host); 322 323 /* Allocate sync point to use for clearing waits for expired fences */ 324 host->nop_sp = _host1x_syncpt_alloc(host, NULL, false); 325 if (!host->nop_sp) 326 return -ENOMEM; 327 328 return 0; 329 } 330 331 struct host1x_syncpt *host1x_syncpt_request(struct device *dev, 332 bool client_managed) 333 { 334 struct host1x *host = dev_get_drvdata(dev->parent); 335 return _host1x_syncpt_alloc(host, dev, client_managed); 336 } 337 338 void host1x_syncpt_free(struct host1x_syncpt *sp) 339 { 340 if (!sp) 341 return; 342 343 kfree(sp->name); 344 sp->dev = NULL; 345 sp->name = NULL; 346 sp->client_managed = false; 347 } 348 349 void host1x_syncpt_deinit(struct host1x *host) 350 { 351 int i; 352 struct host1x_syncpt *sp = host->syncpt; 353 for (i = 0; i < host->info->nb_pts; i++, sp++) 354 kfree(sp->name); 355 } 356 357 int host1x_syncpt_nb_pts(struct host1x *host) 358 { 359 return host->info->nb_pts; 360 } 361 362 int host1x_syncpt_nb_bases(struct host1x *host) 363 { 364 return host->info->nb_bases; 365 } 366 367 int host1x_syncpt_nb_mlocks(struct host1x *host) 368 { 369 return host->info->nb_mlocks; 370 } 371 372 struct host1x_syncpt *host1x_syncpt_get(struct host1x *host, u32 id) 373 { 374 if (host->info->nb_pts < id) 375 return NULL; 376 return host->syncpt + id; 377 } 378