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 #ifndef ACPI_NO_SEMAPHORES 66 #ifndef ACPI_SEMAPHORES_MAX_PENDING 67 #define ACPI_SEMAPHORES_MAX_PENDING 4 68 #endif 69 static int acpi_semaphore_debug = 0; 70 TUNABLE_INT("debug.acpi_semaphore_debug", &acpi_semaphore_debug); 71 SYSCTL_DECL(_debug_acpi); 72 SYSCTL_INT(_debug_acpi, OID_AUTO, semaphore_debug, CTLFLAG_RW, 73 &acpi_semaphore_debug, 0, "Enable ACPI semaphore debug messages"); 74 #endif /* !ACPI_NO_SEMAPHORES */ 75 76 ACPI_STATUS 77 AcpiOsCreateSemaphore(UINT32 MaxUnits, UINT32 InitialUnits, 78 ACPI_HANDLE *OutHandle) 79 { 80 #ifndef ACPI_NO_SEMAPHORES 81 struct acpi_semaphore *as; 82 83 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 84 85 if (OutHandle == NULL) 86 return_ACPI_STATUS (AE_BAD_PARAMETER); 87 if (InitialUnits > MaxUnits) 88 return_ACPI_STATUS (AE_BAD_PARAMETER); 89 90 if ((as = malloc(sizeof(*as), M_ACPISEM, M_NOWAIT | M_ZERO)) == NULL) 91 return_ACPI_STATUS (AE_NO_MEMORY); 92 93 mtx_init(&as->as_mtx, "ACPI semaphore", NULL, MTX_DEF); 94 as->as_units = InitialUnits; 95 as->as_maxunits = MaxUnits; 96 as->as_pendings = as->as_resetting = as->as_timeouts = 0; 97 98 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, 99 "created semaphore %p max %d, initial %d\n", 100 as, InitialUnits, MaxUnits)); 101 102 *OutHandle = (ACPI_HANDLE)as; 103 #else 104 *OutHandle = (ACPI_HANDLE)OutHandle; 105 #endif /* !ACPI_NO_SEMAPHORES */ 106 107 return_ACPI_STATUS (AE_OK); 108 } 109 110 ACPI_STATUS 111 AcpiOsDeleteSemaphore(ACPI_HANDLE Handle) 112 { 113 #ifndef ACPI_NO_SEMAPHORES 114 struct acpi_semaphore *as = (struct acpi_semaphore *)Handle; 115 116 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 117 118 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "destroyed semaphore %p\n", as)); 119 mtx_destroy(&as->as_mtx); 120 free(Handle, M_ACPISEM); 121 #endif /* !ACPI_NO_SEMAPHORES */ 122 123 return_ACPI_STATUS (AE_OK); 124 } 125 126 /* 127 * This implementation has a bug, in that it has to stall for the entire 128 * timeout before it will return AE_TIME. A better implementation would 129 * use getmicrotime() to correctly adjust the timeout after being woken up. 130 */ 131 ACPI_STATUS 132 AcpiOsWaitSemaphore(ACPI_HANDLE Handle, UINT32 Units, UINT16 Timeout) 133 { 134 #ifndef ACPI_NO_SEMAPHORES 135 ACPI_STATUS result; 136 struct acpi_semaphore *as = (struct acpi_semaphore *)Handle; 137 int rv, tmo; 138 struct timeval timeouttv, currenttv, timelefttv; 139 140 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 141 142 if (as == NULL) 143 return_ACPI_STATUS (AE_BAD_PARAMETER); 144 145 if (cold) 146 return_ACPI_STATUS (AE_OK); 147 148 #if 0 149 if (as->as_units < Units && as->as_timeouts > 10) { 150 printf("%s: semaphore %p too many timeouts, resetting\n", __func__, as); 151 AS_LOCK(as); 152 as->as_units = as->as_maxunits; 153 if (as->as_pendings) 154 as->as_resetting = 1; 155 as->as_timeouts = 0; 156 wakeup(as); 157 AS_UNLOCK(as); 158 return_ACPI_STATUS (AE_TIME); 159 } 160 161 if (as->as_resetting) 162 return_ACPI_STATUS (AE_TIME); 163 #endif 164 165 /* a timeout of ACPI_WAIT_FOREVER means "forever" */ 166 if (Timeout == ACPI_WAIT_FOREVER) { 167 tmo = 0; 168 timeouttv.tv_sec = ((0xffff/1000) + 1); /* cf. ACPI spec */ 169 timeouttv.tv_usec = 0; 170 } else { 171 /* compute timeout using microseconds per tick */ 172 tmo = (Timeout * 1000) / (1000000 / hz); 173 if (tmo <= 0) 174 tmo = 1; 175 timeouttv.tv_sec = Timeout / 1000; 176 timeouttv.tv_usec = (Timeout % 1000) * 1000; 177 } 178 179 /* calculate timeout value in timeval */ 180 getmicrotime(¤ttv); 181 timevaladd(&timeouttv, ¤ttv); 182 183 AS_LOCK(as); 184 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, 185 "get %d units from semaphore %p (has %d), timeout %d\n", 186 Units, as, as->as_units, Timeout)); 187 for (;;) { 188 if (as->as_maxunits == ACPI_NO_UNIT_LIMIT) { 189 result = AE_OK; 190 break; 191 } 192 if (as->as_units >= Units) { 193 as->as_units -= Units; 194 result = AE_OK; 195 break; 196 } 197 198 /* limit number of pending treads */ 199 if (as->as_pendings >= ACPI_SEMAPHORES_MAX_PENDING) { 200 result = AE_TIME; 201 break; 202 } 203 204 /* if timeout values of zero is specified, return immediately */ 205 if (Timeout == 0) { 206 result = AE_TIME; 207 break; 208 } 209 210 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, 211 "semaphore blocked, calling msleep(%p, %p, %d, \"acsem\", %d)\n", 212 as, &as->as_mtx, PCATCH, tmo)); 213 214 as->as_pendings++; 215 216 if (acpi_semaphore_debug) { 217 printf("%s: Sleep %d, pending %d, semaphore %p, thread %d\n", 218 __func__, Timeout, as->as_pendings, as, AcpiOsGetThreadId()); 219 } 220 221 rv = msleep(as, &as->as_mtx, PCATCH, "acsem", tmo); 222 223 as->as_pendings--; 224 225 #if 0 226 if (as->as_resetting) { 227 /* semaphore reset, return immediately */ 228 if (as->as_pendings == 0) { 229 as->as_resetting = 0; 230 } 231 result = AE_TIME; 232 break; 233 } 234 #endif 235 236 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "msleep(%d) returned %d\n", tmo, rv)); 237 if (rv == EWOULDBLOCK) { 238 result = AE_TIME; 239 break; 240 } 241 242 /* check if we already awaited enough */ 243 timelefttv = timeouttv; 244 getmicrotime(¤ttv); 245 timevalsub(&timelefttv, ¤ttv); 246 if (timelefttv.tv_sec < 0) { 247 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "await semaphore %p timeout\n", 248 as)); 249 result = AE_TIME; 250 break; 251 } 252 253 /* adjust timeout for the next sleep */ 254 tmo = (timelefttv.tv_sec * 1000000 + timelefttv.tv_usec) / 255 (1000000 / hz); 256 if (tmo <= 0) 257 tmo = 1; 258 259 if (acpi_semaphore_debug) { 260 printf("%s: Wakeup timeleft(%jd, %lu), tmo %u, sem %p, thread %d\n", 261 __func__, (intmax_t)timelefttv.tv_sec, timelefttv.tv_usec, tmo, as, 262 AcpiOsGetThreadId()); 263 } 264 } 265 266 if (acpi_semaphore_debug) { 267 if (result == AE_TIME && Timeout > 0) { 268 printf("%s: Timeout %d, pending %d, semaphore %p\n", 269 __func__, Timeout, as->as_pendings, as); 270 } 271 if (result == AE_OK && (as->as_timeouts > 0 || as->as_pendings > 0)) { 272 printf("%s: Acquire %d, units %d, pending %d, sem %p, thread %d\n", 273 __func__, Units, as->as_units, as->as_pendings, as, 274 AcpiOsGetThreadId()); 275 } 276 } 277 278 if (result == AE_TIME) 279 as->as_timeouts++; 280 else 281 as->as_timeouts = 0; 282 283 AS_UNLOCK(as); 284 return_ACPI_STATUS (result); 285 #else 286 return_ACPI_STATUS (AE_OK); 287 #endif /* !ACPI_NO_SEMAPHORES */ 288 } 289 290 ACPI_STATUS 291 AcpiOsSignalSemaphore(ACPI_HANDLE Handle, UINT32 Units) 292 { 293 #ifndef ACPI_NO_SEMAPHORES 294 struct acpi_semaphore *as = (struct acpi_semaphore *)Handle; 295 296 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__); 297 298 if (as == NULL) 299 return_ACPI_STATUS(AE_BAD_PARAMETER); 300 301 AS_LOCK(as); 302 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, 303 "return %d units to semaphore %p (has %d)\n", 304 Units, as, as->as_units)); 305 if (as->as_maxunits != ACPI_NO_UNIT_LIMIT) { 306 as->as_units += Units; 307 if (as->as_units > as->as_maxunits) 308 as->as_units = as->as_maxunits; 309 } 310 311 if (acpi_semaphore_debug && (as->as_timeouts > 0 || as->as_pendings > 0)) { 312 printf("%s: Release %d, units %d, pending %d, semaphore %p, thread %d\n", 313 __func__, Units, as->as_units, as->as_pendings, as, AcpiOsGetThreadId()); 314 } 315 316 wakeup(as); 317 AS_UNLOCK(as); 318 #endif /* !ACPI_NO_SEMAPHORES */ 319 320 return_ACPI_STATUS (AE_OK); 321 } 322 323 ACPI_STATUS 324 AcpiOsCreateLock (ACPI_HANDLE *OutHandle) 325 { 326 struct mtx *m; 327 328 if (OutHandle == NULL) 329 return (AE_BAD_PARAMETER); 330 m = malloc(sizeof(*m), M_ACPISEM, M_NOWAIT | M_ZERO); 331 if (m == NULL) 332 return (AE_NO_MEMORY); 333 334 mtx_init(m, "acpica subsystem lock", NULL, MTX_DEF); 335 *OutHandle = (ACPI_HANDLE)m; 336 return (AE_OK); 337 } 338 339 void 340 AcpiOsDeleteLock (ACPI_HANDLE Handle) 341 { 342 struct mtx *m = (struct mtx *)Handle; 343 344 if (Handle == NULL) 345 return; 346 mtx_destroy(m); 347 } 348 349 /* 350 * The Flags parameter seems to state whether or not caller is an ISR 351 * (and thus can't block) but since we have ithreads, we don't worry 352 * about potentially blocking. 353 */ 354 ACPI_NATIVE_UINT 355 AcpiOsAcquireLock (ACPI_HANDLE Handle) 356 { 357 struct mtx *m = (struct mtx *)Handle; 358 359 if (Handle == NULL) 360 return (0); 361 mtx_lock(m); 362 return (0); 363 } 364 365 void 366 AcpiOsReleaseLock (ACPI_HANDLE Handle, ACPI_NATIVE_UINT Flags) 367 { 368 struct mtx *m = (struct mtx *)Handle; 369 370 if (Handle == NULL) 371 return; 372 mtx_unlock(m); 373 } 374 375 /* Section 5.2.9.1: global lock acquire/release functions */ 376 #define GL_ACQUIRED (-1) 377 #define GL_BUSY 0 378 #define GL_BIT_PENDING 0x1 379 #define GL_BIT_OWNED 0x2 380 #define GL_BIT_MASK (GL_BIT_PENDING | GL_BIT_OWNED) 381 382 /* 383 * Acquire the global lock. If busy, set the pending bit. The caller 384 * will wait for notification from the BIOS that the lock is available 385 * and then attempt to acquire it again. 386 */ 387 int 388 acpi_acquire_global_lock(uint32_t *lock) 389 { 390 uint32_t new, old; 391 392 do { 393 old = *lock; 394 new = ((old & ~GL_BIT_MASK) | GL_BIT_OWNED) | 395 ((old >> 1) & GL_BIT_PENDING); 396 } while (atomic_cmpset_acq_int(lock, old, new) == 0); 397 398 return ((new < GL_BIT_MASK) ? GL_ACQUIRED : GL_BUSY); 399 } 400 401 /* 402 * Release the global lock, returning whether there is a waiter pending. 403 * If the BIOS set the pending bit, OSPM must notify the BIOS when it 404 * releases the lock. 405 */ 406 int 407 acpi_release_global_lock(uint32_t *lock) 408 { 409 uint32_t new, old; 410 411 do { 412 old = *lock; 413 new = old & ~GL_BIT_MASK; 414 } while (atomic_cmpset_rel_int(lock, old, new) == 0); 415 416 return (old & GL_BIT_PENDING); 417 } 418