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 * $FreeBSD$ 28 */ 29 30 /* 31 * 6.1 : Mutual Exclusion and Synchronisation 32 */ 33 34 #include "acpi.h" 35 36 #include "opt_acpi.h" 37 #include <sys/kernel.h> 38 #include <sys/malloc.h> 39 #include <sys/sysctl.h> 40 #include <sys/lock.h> 41 #include <sys/mutex.h> 42 43 #define _COMPONENT ACPI_OS_SERVICES 44 ACPI_MODULE_NAME("SYNCH") 45 46 MALLOC_DEFINE(M_ACPISEM, "acpisem", "ACPI semaphore"); 47 48 #define AS_LOCK(as) mtx_lock(&(as)->as_mtx) 49 #define AS_UNLOCK(as) mtx_unlock(&(as)->as_mtx) 50 51 /* 52 * Simple counting semaphore implemented using a mutex. (Subsequently used 53 * in the OSI code to implement a mutex. Go figure.) 54 */ 55 struct acpi_semaphore { 56 struct mtx as_mtx; 57 UINT32 as_units; 58 UINT32 as_maxunits; 59 UINT32 as_pendings; 60 UINT32 as_resetting; 61 UINT32 as_timeouts; 62 }; 63 64 #ifndef ACPI_NO_SEMAPHORES 65 #ifndef ACPI_SEMAPHORES_MAX_PENDING 66 #define ACPI_SEMAPHORES_MAX_PENDING 4 67 #endif 68 static int acpi_semaphore_debug = 0; 69 TUNABLE_INT("debug.acpi_semaphore_debug", &acpi_semaphore_debug); 70 SYSCTL_DECL(_debug_acpi); 71 SYSCTL_INT(_debug_acpi, OID_AUTO, semaphore_debug, CTLFLAG_RW, 72 &acpi_semaphore_debug, 0, "Enable ACPI semaphore debug messages"); 73 #endif /* !ACPI_NO_SEMAPHORES */ 74 75 ACPI_STATUS 76 AcpiOsCreateSemaphore(UINT32 MaxUnits, UINT32 InitialUnits, 77 ACPI_HANDLE *OutHandle) 78 { 79 #ifndef ACPI_NO_SEMAPHORES 80 struct acpi_semaphore *as; 81 82 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 83 84 if (OutHandle == NULL) 85 return_ACPI_STATUS (AE_BAD_PARAMETER); 86 if (InitialUnits > MaxUnits) 87 return_ACPI_STATUS (AE_BAD_PARAMETER); 88 89 if ((as = malloc(sizeof(*as), M_ACPISEM, M_NOWAIT | M_ZERO)) == NULL) 90 return_ACPI_STATUS (AE_NO_MEMORY); 91 92 mtx_init(&as->as_mtx, "ACPI semaphore", NULL, MTX_DEF); 93 as->as_units = InitialUnits; 94 as->as_maxunits = MaxUnits; 95 as->as_pendings = as->as_resetting = as->as_timeouts = 0; 96 97 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, 98 "created semaphore %p max %d, initial %d\n", 99 as, InitialUnits, MaxUnits)); 100 101 *OutHandle = (ACPI_HANDLE)as; 102 #else 103 *OutHandle = (ACPI_HANDLE)OutHandle; 104 #endif /* !ACPI_NO_SEMAPHORES */ 105 106 return_ACPI_STATUS (AE_OK); 107 } 108 109 ACPI_STATUS 110 AcpiOsDeleteSemaphore(ACPI_HANDLE Handle) 111 { 112 #ifndef ACPI_NO_SEMAPHORES 113 struct acpi_semaphore *as = (struct acpi_semaphore *)Handle; 114 115 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 116 117 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "destroyed semaphore %p\n", as)); 118 mtx_destroy(&as->as_mtx); 119 free(Handle, M_ACPISEM); 120 #endif /* !ACPI_NO_SEMAPHORES */ 121 122 return_ACPI_STATUS (AE_OK); 123 } 124 125 /* 126 * This implementation has a bug, in that it has to stall for the entire 127 * timeout before it will return AE_TIME. A better implementation would 128 * use getmicrotime() to correctly adjust the timeout after being woken up. 129 */ 130 ACPI_STATUS 131 AcpiOsWaitSemaphore(ACPI_HANDLE Handle, UINT32 Units, UINT16 Timeout) 132 { 133 #ifndef ACPI_NO_SEMAPHORES 134 ACPI_STATUS result; 135 struct acpi_semaphore *as = (struct acpi_semaphore *)Handle; 136 int rv, tmo; 137 struct timeval timeouttv, currenttv, timelefttv; 138 139 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 140 141 if (as == NULL) 142 return_ACPI_STATUS (AE_BAD_PARAMETER); 143 144 if (cold) 145 return_ACPI_STATUS (AE_OK); 146 147 #if 0 148 if (as->as_units < Units && as->as_timeouts > 10) { 149 printf("%s: semaphore %p too many timeouts, resetting\n", __func__, as); 150 AS_LOCK(as); 151 as->as_units = as->as_maxunits; 152 if (as->as_pendings) 153 as->as_resetting = 1; 154 as->as_timeouts = 0; 155 wakeup(as); 156 AS_UNLOCK(as); 157 return_ACPI_STATUS (AE_TIME); 158 } 159 160 if (as->as_resetting) 161 return_ACPI_STATUS (AE_TIME); 162 #endif 163 164 /* a timeout of ACPI_WAIT_FOREVER means "forever" */ 165 if (Timeout == ACPI_WAIT_FOREVER) { 166 tmo = 0; 167 timeouttv.tv_sec = ((0xffff/1000) + 1); /* cf. ACPI spec */ 168 timeouttv.tv_usec = 0; 169 } else { 170 /* compute timeout using microseconds per tick */ 171 tmo = (Timeout * 1000) / (1000000 / hz); 172 if (tmo <= 0) 173 tmo = 1; 174 timeouttv.tv_sec = Timeout / 1000; 175 timeouttv.tv_usec = (Timeout % 1000) * 1000; 176 } 177 178 /* calculate timeout value in timeval */ 179 getmicrotime(¤ttv); 180 timevaladd(&timeouttv, ¤ttv); 181 182 AS_LOCK(as); 183 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, 184 "get %d units from semaphore %p (has %d), timeout %d\n", 185 Units, as, as->as_units, Timeout)); 186 for (;;) { 187 if (as->as_maxunits == ACPI_NO_UNIT_LIMIT) { 188 result = AE_OK; 189 break; 190 } 191 if (as->as_units >= Units) { 192 as->as_units -= Units; 193 result = AE_OK; 194 break; 195 } 196 197 /* limit number of pending treads */ 198 if (as->as_pendings >= ACPI_SEMAPHORES_MAX_PENDING) { 199 result = AE_TIME; 200 break; 201 } 202 203 /* if timeout values of zero is specified, return immediately */ 204 if (Timeout == 0) { 205 result = AE_TIME; 206 break; 207 } 208 209 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, 210 "semaphore blocked, calling msleep(%p, %p, %d, \"acsem\", %d)\n", 211 as, &as->as_mtx, PCATCH, tmo)); 212 213 as->as_pendings++; 214 215 if (acpi_semaphore_debug) { 216 printf("%s: Sleep %d, pending %d, semaphore %p, thread %d\n", 217 __func__, Timeout, as->as_pendings, as, AcpiOsGetThreadId()); 218 } 219 220 rv = msleep(as, &as->as_mtx, PCATCH, "acsem", tmo); 221 222 as->as_pendings--; 223 224 #if 0 225 if (as->as_resetting) { 226 /* semaphore reset, return immediately */ 227 if (as->as_pendings == 0) { 228 as->as_resetting = 0; 229 } 230 result = AE_TIME; 231 break; 232 } 233 #endif 234 235 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "msleep(%d) returned %d\n", tmo, rv)); 236 if (rv == EWOULDBLOCK) { 237 result = AE_TIME; 238 break; 239 } 240 241 /* check if we already awaited enough */ 242 timelefttv = timeouttv; 243 getmicrotime(¤ttv); 244 timevalsub(&timelefttv, ¤ttv); 245 if (timelefttv.tv_sec < 0) { 246 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "await semaphore %p timeout\n", 247 as)); 248 result = AE_TIME; 249 break; 250 } 251 252 /* adjust timeout for the next sleep */ 253 tmo = (timelefttv.tv_sec * 1000000 + timelefttv.tv_usec) / 254 (1000000 / hz); 255 if (tmo <= 0) 256 tmo = 1; 257 258 if (acpi_semaphore_debug) { 259 printf("%s: Wakeup timeleft(%lu, %lu), tmo %u, sem %p, thread %d\n", 260 __func__, timelefttv.tv_sec, timelefttv.tv_usec, tmo, as, 261 AcpiOsGetThreadId()); 262 } 263 } 264 265 if (acpi_semaphore_debug) { 266 if (result == AE_TIME && Timeout > 0) { 267 printf("%s: Timeout %d, pending %d, semaphore %p\n", 268 __func__, Timeout, as->as_pendings, as); 269 } 270 if (result == AE_OK && (as->as_timeouts > 0 || as->as_pendings > 0)) { 271 printf("%s: Acquire %d, units %d, pending %d, sem %p, thread %d\n", 272 __func__, Units, as->as_units, as->as_pendings, as, 273 AcpiOsGetThreadId()); 274 } 275 } 276 277 if (result == AE_TIME) 278 as->as_timeouts++; 279 else 280 as->as_timeouts = 0; 281 282 AS_UNLOCK(as); 283 return_ACPI_STATUS (result); 284 #else 285 return_ACPI_STATUS (AE_OK); 286 #endif /* !ACPI_NO_SEMAPHORES */ 287 } 288 289 ACPI_STATUS 290 AcpiOsSignalSemaphore(ACPI_HANDLE Handle, UINT32 Units) 291 { 292 #ifndef ACPI_NO_SEMAPHORES 293 struct acpi_semaphore *as = (struct acpi_semaphore *)Handle; 294 295 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 296 297 if (as == NULL) 298 return_ACPI_STATUS(AE_BAD_PARAMETER); 299 300 AS_LOCK(as); 301 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, 302 "return %d units to semaphore %p (has %d)\n", 303 Units, as, as->as_units)); 304 if (as->as_maxunits != ACPI_NO_UNIT_LIMIT) { 305 as->as_units += Units; 306 if (as->as_units > as->as_maxunits) 307 as->as_units = as->as_maxunits; 308 } 309 310 if (acpi_semaphore_debug && (as->as_timeouts > 0 || as->as_pendings > 0)) { 311 printf("%s: Release %d, units %d, pending %d, semaphore %p, thread %d\n", 312 __func__, Units, as->as_units, as->as_pendings, as, AcpiOsGetThreadId()); 313 } 314 315 wakeup(as); 316 AS_UNLOCK(as); 317 #endif /* !ACPI_NO_SEMAPHORES */ 318 319 return_ACPI_STATUS (AE_OK); 320 } 321 322 ACPI_STATUS 323 AcpiOsCreateLock (ACPI_HANDLE *OutHandle) 324 { 325 struct mtx *m; 326 327 if (OutHandle == NULL) 328 return (AE_BAD_PARAMETER); 329 m = malloc(sizeof(*m), M_ACPISEM, M_NOWAIT | M_ZERO); 330 if (m == NULL) 331 return (AE_NO_MEMORY); 332 333 mtx_init(m, "acpica subsystem lock", NULL, MTX_DEF); 334 *OutHandle = (ACPI_HANDLE)m; 335 return (AE_OK); 336 } 337 338 void 339 AcpiOsDeleteLock (ACPI_HANDLE Handle) 340 { 341 struct mtx *m = (struct mtx *)Handle; 342 343 if (Handle == NULL) 344 return; 345 mtx_destroy(m); 346 } 347 348 /* 349 * The Flags parameter seems to state whether or not caller is an ISR 350 * (and thus can't block) but since we have ithreads, we don't worry 351 * about potentially blocking. 352 */ 353 void 354 AcpiOsAcquireLock (ACPI_HANDLE Handle, UINT32 Flags) 355 { 356 struct mtx *m = (struct mtx *)Handle; 357 358 if (Handle == NULL) 359 return; 360 mtx_lock(m); 361 } 362 363 void 364 AcpiOsReleaseLock (ACPI_HANDLE Handle, UINT32 Flags) 365 { 366 struct mtx *m = (struct mtx *)Handle; 367 368 if (Handle == NULL) 369 return; 370 mtx_unlock(m); 371 } 372 373 /* Section 5.2.9.1: global lock acquire/release functions */ 374 #define GL_ACQUIRED (-1) 375 #define GL_BUSY 0 376 #define GL_BIT_PENDING 0x1 377 #define GL_BIT_OWNED 0x2 378 #define GL_BIT_MASK (GL_BIT_PENDING | GL_BIT_OWNED) 379 380 /* 381 * Acquire the global lock. If busy, set the pending bit. The caller 382 * will wait for notification from the BIOS that the lock is available 383 * and then attempt to acquire it again. 384 */ 385 int 386 acpi_acquire_global_lock(uint32_t *lock) 387 { 388 uint32_t new, old; 389 390 do { 391 old = *lock; 392 new = ((old & ~GL_BIT_MASK) | GL_BIT_OWNED) | 393 ((old >> 1) & GL_BIT_PENDING); 394 } while (atomic_cmpset_acq_int(lock, old, new) == 0); 395 396 return ((new < GL_BIT_MASK) ? GL_ACQUIRED : GL_BUSY); 397 } 398 399 /* 400 * Release the global lock, returning whether there is a waiter pending. 401 * If the BIOS set the pending bit, OSPM must notify the BIOS when it 402 * releases the lock. 403 */ 404 int 405 acpi_release_global_lock(uint32_t *lock) 406 { 407 uint32_t new, old; 408 409 do { 410 old = *lock; 411 new = old & ~GL_BIT_MASK; 412 } while (atomic_cmpset_rel_int(lock, old, new) == 0); 413 414 return (old & GL_BIT_PENDING); 415 } 416