1 /*- 2 * Copyright (c) 2000 Michael Smith 3 * Copyright (c) 2000 BSDi 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 /* 29 * 6.1 : Mutual Exclusion and Synchronisation 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include <contrib/dev/acpica/acpi.h> 36 37 #include "opt_acpi.h" 38 #include <sys/kernel.h> 39 #include <sys/malloc.h> 40 #include <sys/sysctl.h> 41 #include <sys/lock.h> 42 #include <sys/mutex.h> 43 44 #define _COMPONENT ACPI_OS_SERVICES 45 ACPI_MODULE_NAME("SYNCH") 46 47 MALLOC_DEFINE(M_ACPISEM, "acpisem", "ACPI semaphore"); 48 49 #define AS_LOCK(as) mtx_lock(&(as)->as_mtx) 50 #define AS_UNLOCK(as) mtx_unlock(&(as)->as_mtx) 51 52 /* 53 * Simple counting semaphore implemented using a mutex. (Subsequently used 54 * in the OSI code to implement a mutex. Go figure.) 55 */ 56 struct acpi_semaphore { 57 struct mtx as_mtx; 58 UINT32 as_units; 59 UINT32 as_maxunits; 60 UINT32 as_pendings; 61 UINT32 as_resetting; 62 UINT32 as_timeouts; 63 }; 64 65 /* Default number of maximum pending threads. */ 66 #ifndef ACPI_NO_SEMAPHORES 67 #ifndef ACPI_SEMAPHORES_MAX_PENDING 68 #define ACPI_SEMAPHORES_MAX_PENDING 4 69 #endif 70 71 static int acpi_semaphore_debug = 0; 72 TUNABLE_INT("debug.acpi_semaphore_debug", &acpi_semaphore_debug); 73 SYSCTL_DECL(_debug_acpi); 74 SYSCTL_INT(_debug_acpi, OID_AUTO, semaphore_debug, CTLFLAG_RW, 75 &acpi_semaphore_debug, 0, "Enable ACPI semaphore debug messages"); 76 #endif /* !ACPI_NO_SEMAPHORES */ 77 78 ACPI_STATUS 79 AcpiOsCreateSemaphore(UINT32 MaxUnits, UINT32 InitialUnits, 80 ACPI_SEMAPHORE *OutHandle) 81 { 82 #ifndef ACPI_NO_SEMAPHORES 83 struct acpi_semaphore *as; 84 85 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 86 87 if (OutHandle == NULL) 88 return_ACPI_STATUS (AE_BAD_PARAMETER); 89 if (InitialUnits > MaxUnits) 90 return_ACPI_STATUS (AE_BAD_PARAMETER); 91 92 if ((as = malloc(sizeof(*as), M_ACPISEM, M_NOWAIT | M_ZERO)) == NULL) 93 return_ACPI_STATUS (AE_NO_MEMORY); 94 95 mtx_init(&as->as_mtx, "ACPI semaphore", NULL, MTX_DEF); 96 as->as_units = InitialUnits; 97 as->as_maxunits = MaxUnits; 98 as->as_pendings = as->as_resetting = as->as_timeouts = 0; 99 100 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, 101 "created semaphore %p max %d, initial %d\n", 102 as, InitialUnits, MaxUnits)); 103 104 *OutHandle = (ACPI_HANDLE)as; 105 #else 106 *OutHandle = (ACPI_HANDLE)OutHandle; 107 #endif /* !ACPI_NO_SEMAPHORES */ 108 109 return_ACPI_STATUS (AE_OK); 110 } 111 112 ACPI_STATUS 113 AcpiOsDeleteSemaphore(ACPI_SEMAPHORE Handle) 114 { 115 #ifndef ACPI_NO_SEMAPHORES 116 struct acpi_semaphore *as = (struct acpi_semaphore *)Handle; 117 118 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 119 120 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "destroyed semaphore %p\n", as)); 121 mtx_destroy(&as->as_mtx); 122 free(Handle, M_ACPISEM); 123 #endif /* !ACPI_NO_SEMAPHORES */ 124 125 return_ACPI_STATUS (AE_OK); 126 } 127 128 /* 129 * This implementation has a bug, in that it has to stall for the entire 130 * timeout before it will return AE_TIME. A better implementation would 131 * use getmicrotime() to correctly adjust the timeout after being woken up. 132 */ 133 ACPI_STATUS 134 AcpiOsWaitSemaphore(ACPI_SEMAPHORE Handle, UINT32 Units, UINT16 Timeout) 135 { 136 #ifndef ACPI_NO_SEMAPHORES 137 ACPI_STATUS result; 138 struct acpi_semaphore *as = (struct acpi_semaphore *)Handle; 139 int rv, tmo; 140 struct timeval timeouttv, currenttv, timelefttv; 141 142 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 143 144 if (as == NULL) 145 return_ACPI_STATUS (AE_BAD_PARAMETER); 146 147 if (cold) 148 return_ACPI_STATUS (AE_OK); 149 150 #if 0 151 if (as->as_units < Units && as->as_timeouts > 10) { 152 printf("%s: semaphore %p too many timeouts, resetting\n", __func__, as); 153 AS_LOCK(as); 154 as->as_units = as->as_maxunits; 155 if (as->as_pendings) 156 as->as_resetting = 1; 157 as->as_timeouts = 0; 158 wakeup(as); 159 AS_UNLOCK(as); 160 return_ACPI_STATUS (AE_TIME); 161 } 162 163 if (as->as_resetting) 164 return_ACPI_STATUS (AE_TIME); 165 #endif 166 167 /* a timeout of ACPI_WAIT_FOREVER means "forever" */ 168 if (Timeout == ACPI_WAIT_FOREVER) { 169 tmo = 0; 170 timeouttv.tv_sec = ((0xffff/1000) + 1); /* cf. ACPI spec */ 171 timeouttv.tv_usec = 0; 172 } else { 173 /* compute timeout using microseconds per tick */ 174 tmo = (Timeout * 1000) / (1000000 / hz); 175 if (tmo <= 0) 176 tmo = 1; 177 timeouttv.tv_sec = Timeout / 1000; 178 timeouttv.tv_usec = (Timeout % 1000) * 1000; 179 } 180 181 /* calculate timeout value in timeval */ 182 getmicrotime(¤ttv); 183 timevaladd(&timeouttv, ¤ttv); 184 185 AS_LOCK(as); 186 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, 187 "get %d units from semaphore %p (has %d), timeout %d\n", 188 Units, as, as->as_units, Timeout)); 189 for (;;) { 190 if (as->as_maxunits == ACPI_NO_UNIT_LIMIT) { 191 result = AE_OK; 192 break; 193 } 194 if (as->as_units >= Units) { 195 as->as_units -= Units; 196 result = AE_OK; 197 break; 198 } 199 200 /* limit number of pending threads */ 201 if (as->as_pendings >= ACPI_SEMAPHORES_MAX_PENDING) { 202 result = AE_TIME; 203 break; 204 } 205 206 /* if timeout values of zero is specified, return immediately */ 207 if (Timeout == 0) { 208 result = AE_TIME; 209 break; 210 } 211 212 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, 213 "semaphore blocked, calling msleep(%p, %p, %d, \"acsem\", %d)\n", 214 as, &as->as_mtx, PCATCH, tmo)); 215 216 as->as_pendings++; 217 218 if (acpi_semaphore_debug) { 219 printf("%s: Sleep %d, pending %d, semaphore %p, thread %d\n", 220 __func__, Timeout, as->as_pendings, as, AcpiOsGetThreadId()); 221 } 222 223 rv = msleep(as, &as->as_mtx, PCATCH, "acsem", tmo); 224 225 as->as_pendings--; 226 227 #if 0 228 if (as->as_resetting) { 229 /* semaphore reset, return immediately */ 230 if (as->as_pendings == 0) { 231 as->as_resetting = 0; 232 } 233 result = AE_TIME; 234 break; 235 } 236 #endif 237 238 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "msleep(%d) returned %d\n", tmo, rv)); 239 if (rv == EWOULDBLOCK) { 240 result = AE_TIME; 241 break; 242 } 243 244 /* check if we already awaited enough */ 245 timelefttv = timeouttv; 246 getmicrotime(¤ttv); 247 timevalsub(&timelefttv, ¤ttv); 248 if (timelefttv.tv_sec < 0) { 249 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "await semaphore %p timeout\n", 250 as)); 251 result = AE_TIME; 252 break; 253 } 254 255 /* adjust timeout for the next sleep */ 256 tmo = (timelefttv.tv_sec * 1000000 + timelefttv.tv_usec) / 257 (1000000 / hz); 258 if (tmo <= 0) 259 tmo = 1; 260 261 if (acpi_semaphore_debug) { 262 printf("%s: Wakeup timeleft(%jd, %lu), tmo %u, sem %p, thread %d\n", 263 __func__, (intmax_t)timelefttv.tv_sec, timelefttv.tv_usec, tmo, as, 264 AcpiOsGetThreadId()); 265 } 266 } 267 268 if (acpi_semaphore_debug) { 269 if (result == AE_TIME && Timeout > 0) { 270 printf("%s: Timeout %d, pending %d, semaphore %p\n", 271 __func__, Timeout, as->as_pendings, as); 272 } 273 if (result == AE_OK && (as->as_timeouts > 0 || as->as_pendings > 0)) { 274 printf("%s: Acquire %d, units %d, pending %d, sem %p, thread %d\n", 275 __func__, Units, as->as_units, as->as_pendings, as, 276 AcpiOsGetThreadId()); 277 } 278 } 279 280 if (result == AE_TIME) 281 as->as_timeouts++; 282 else 283 as->as_timeouts = 0; 284 285 AS_UNLOCK(as); 286 return_ACPI_STATUS (result); 287 #else 288 return_ACPI_STATUS (AE_OK); 289 #endif /* !ACPI_NO_SEMAPHORES */ 290 } 291 292 ACPI_STATUS 293 AcpiOsSignalSemaphore(ACPI_SEMAPHORE Handle, UINT32 Units) 294 { 295 #ifndef ACPI_NO_SEMAPHORES 296 struct acpi_semaphore *as = (struct acpi_semaphore *)Handle; 297 298 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 299 300 if (as == NULL) 301 return_ACPI_STATUS(AE_BAD_PARAMETER); 302 303 AS_LOCK(as); 304 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, 305 "return %d units to semaphore %p (has %d)\n", 306 Units, as, as->as_units)); 307 if (as->as_maxunits != ACPI_NO_UNIT_LIMIT) { 308 as->as_units += Units; 309 if (as->as_units > as->as_maxunits) 310 as->as_units = as->as_maxunits; 311 } 312 313 if (acpi_semaphore_debug && (as->as_timeouts > 0 || as->as_pendings > 0)) { 314 printf("%s: Release %d, units %d, pending %d, semaphore %p, thread %d\n", 315 __func__, Units, as->as_units, as->as_pendings, as, AcpiOsGetThreadId()); 316 } 317 318 wakeup(as); 319 AS_UNLOCK(as); 320 #endif /* !ACPI_NO_SEMAPHORES */ 321 322 return_ACPI_STATUS (AE_OK); 323 } 324 325 /* Combined mutex + mutex name storage since the latter must persist. */ 326 struct acpi_spinlock { 327 struct mtx lock; 328 char name[32]; 329 }; 330 331 ACPI_STATUS 332 AcpiOsCreateLock (ACPI_SPINLOCK *OutHandle) 333 { 334 struct acpi_spinlock *h; 335 336 if (OutHandle == NULL) 337 return (AE_BAD_PARAMETER); 338 h = malloc(sizeof(*h), M_ACPISEM, M_NOWAIT | M_ZERO); 339 if (h == NULL) 340 return (AE_NO_MEMORY); 341 342 /* Build a unique name based on the address of the handle. */ 343 if (OutHandle == &AcpiGbl_GpeLock) 344 snprintf(h->name, sizeof(h->name), "acpi subsystem GPE lock"); 345 else if (OutHandle == &AcpiGbl_HardwareLock) 346 snprintf(h->name, sizeof(h->name), "acpi subsystem HW lock"); 347 else 348 snprintf(h->name, sizeof(h->name), "acpi subsys %p", OutHandle); 349 mtx_init(&h->lock, h->name, NULL, MTX_DEF|MTX_RECURSE); 350 *OutHandle = (ACPI_SPINLOCK)h; 351 return (AE_OK); 352 } 353 354 void 355 AcpiOsDeleteLock (ACPI_SPINLOCK Handle) 356 { 357 struct acpi_spinlock *h = (struct acpi_spinlock *)Handle; 358 359 if (Handle == NULL) 360 return; 361 mtx_destroy(&h->lock); 362 free(h, M_ACPISEM); 363 } 364 365 /* 366 * The Flags parameter seems to state whether or not caller is an ISR 367 * (and thus can't block) but since we have ithreads, we don't worry 368 * about potentially blocking. 369 */ 370 ACPI_NATIVE_UINT 371 AcpiOsAcquireLock (ACPI_SPINLOCK Handle) 372 { 373 struct acpi_spinlock *h = (struct acpi_spinlock *)Handle; 374 375 if (Handle == NULL) 376 return (0); 377 mtx_lock(&h->lock); 378 return (0); 379 } 380 381 void 382 AcpiOsReleaseLock (ACPI_SPINLOCK Handle, ACPI_CPU_FLAGS Flags) 383 { 384 struct acpi_spinlock *h = (struct acpi_spinlock *)Handle; 385 386 if (Handle == NULL) 387 return; 388 mtx_unlock(&h->lock); 389 } 390 391 /* Section 5.2.9.1: global lock acquire/release functions */ 392 #define GL_ACQUIRED (-1) 393 #define GL_BUSY 0 394 #define GL_BIT_PENDING 0x1 395 #define GL_BIT_OWNED 0x2 396 #define GL_BIT_MASK (GL_BIT_PENDING | GL_BIT_OWNED) 397 398 /* 399 * Acquire the global lock. If busy, set the pending bit. The caller 400 * will wait for notification from the BIOS that the lock is available 401 * and then attempt to acquire it again. 402 */ 403 int 404 acpi_acquire_global_lock(uint32_t *lock) 405 { 406 uint32_t new, old; 407 408 do { 409 old = *lock; 410 new = ((old & ~GL_BIT_MASK) | GL_BIT_OWNED) | 411 ((old >> 1) & GL_BIT_PENDING); 412 } while (atomic_cmpset_acq_int(lock, old, new) == 0); 413 414 return ((new < GL_BIT_MASK) ? GL_ACQUIRED : GL_BUSY); 415 } 416 417 /* 418 * Release the global lock, returning whether there is a waiter pending. 419 * If the BIOS set the pending bit, OSPM must notify the BIOS when it 420 * releases the lock. 421 */ 422 int 423 acpi_release_global_lock(uint32_t *lock) 424 { 425 uint32_t new, old; 426 427 do { 428 old = *lock; 429 new = old & ~GL_BIT_MASK; 430 } while (atomic_cmpset_rel_int(lock, old, new) == 0); 431 432 return (old & GL_BIT_PENDING); 433 } 434