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: src/sys/dev/acpica/Osd/OsdSynch.c,v 1.21 2004/05/05 20:07:52 njl Exp $
28 */
29
30 /*
31 * Mutual Exclusion and Synchronisation
32 */
33
34 #include "acpi.h"
35 #include "accommon.h"
36
37 #include "opt_acpi.h"
38
39 #include <sys/kernel.h>
40 #include <sys/bus.h>
41 #include <sys/malloc.h>
42 #include <sys/sysctl.h>
43 #include <sys/lock.h>
44 #include <sys/thread.h>
45 #include <sys/thread2.h>
46 #include <sys/spinlock2.h>
47
48 #include <dev/acpica/acpivar.h>
49
50 #define _COMPONENT ACPI_OS_SERVICES
51 ACPI_MODULE_NAME("SYNCH")
52
53 MALLOC_DEFINE(M_ACPISEM, "acpisem", "ACPI semaphore");
54
55 #define AS_LOCK(as) spin_lock(&(as)->as_spin)
56 #define AS_UNLOCK(as) spin_unlock(&(as)->as_spin)
57 #define AS_LOCK_DECL
58
59 /*
60 * Simple counting semaphore implemented using a mutex. (Subsequently used
61 * in the OSI code to implement a mutex. Go figure.)
62 */
63 struct acpi_semaphore {
64 struct spinlock as_spin;
65 UINT32 as_units;
66 UINT32 as_maxunits;
67 UINT32 as_pendings;
68 UINT32 as_resetting;
69 UINT32 as_timeouts;
70 };
71
72 #ifndef ACPI_SEMAPHORES_MAX_PENDING
73 #define ACPI_SEMAPHORES_MAX_PENDING 0x1FFFFFFF
74 #endif
75 static int acpi_semaphore_debug = 0;
76 TUNABLE_INT("debug.acpi_semaphore_debug", &acpi_semaphore_debug);
77 SYSCTL_INT(_debug_acpi, OID_AUTO, semaphore_debug, CTLFLAG_RW,
78 &acpi_semaphore_debug, 0, "Enable ACPI semaphore debug messages");
79
80 ACPI_STATUS
AcpiOsCreateSemaphore(UINT32 MaxUnits,UINT32 InitialUnits,ACPI_HANDLE * OutHandle)81 AcpiOsCreateSemaphore(UINT32 MaxUnits, UINT32 InitialUnits,
82 ACPI_HANDLE *OutHandle)
83 {
84 struct acpi_semaphore *as;
85
86 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
87
88 if (OutHandle == NULL)
89 return_ACPI_STATUS (AE_BAD_PARAMETER);
90 if (InitialUnits > MaxUnits)
91 return_ACPI_STATUS (AE_BAD_PARAMETER);
92
93 as = kmalloc(sizeof(*as), M_ACPISEM, M_INTWAIT | M_ZERO);
94
95 spin_init(&as->as_spin, "AcpiOsSem");
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
106 return_ACPI_STATUS (AE_OK);
107 }
108
109 ACPI_STATUS
AcpiOsDeleteSemaphore(ACPI_HANDLE Handle)110 AcpiOsDeleteSemaphore(ACPI_HANDLE Handle)
111 {
112 struct acpi_semaphore *as = (struct acpi_semaphore *)Handle;
113
114 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
115
116 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "destroyed semaphore %p\n", as));
117 spin_uninit(&as->as_spin);
118 kfree(as, M_ACPISEM);
119
120 return_ACPI_STATUS (AE_OK);
121 }
122
123 ACPI_STATUS
AcpiOsWaitSemaphore(ACPI_HANDLE Handle,UINT32 Units,UINT16 Timeout)124 AcpiOsWaitSemaphore(ACPI_HANDLE Handle, UINT32 Units, UINT16 Timeout)
125 {
126 ACPI_STATUS result;
127 struct acpi_semaphore *as = (struct acpi_semaphore *)Handle;
128 int rv, tmo;
129 struct timeval timeouttv, currenttv, timelefttv;
130 AS_LOCK_DECL;
131
132 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
133
134 if (as == NULL)
135 return_ACPI_STATUS (AE_BAD_PARAMETER);
136
137 if (cold)
138 return_ACPI_STATUS (AE_OK);
139
140 #if 0
141 if (as->as_units < Units && as->as_timeouts > 10) {
142 kprintf("%s: semaphore %p too many timeouts, resetting\n", __func__, as);
143 AS_LOCK(as);
144 as->as_units = as->as_maxunits;
145 if (as->as_pendings)
146 as->as_resetting = 1;
147 as->as_timeouts = 0;
148 wakeup(as);
149 AS_UNLOCK(as);
150 return_ACPI_STATUS (AE_TIME);
151 }
152
153 if (as->as_resetting)
154 return_ACPI_STATUS (AE_TIME);
155 #endif
156
157 /* a timeout of ACPI_WAIT_FOREVER means "forever" */
158 if (Timeout == ACPI_WAIT_FOREVER) {
159 tmo = 0;
160 timeouttv.tv_sec = ((0xffff/1000) + 1); /* cf. ACPI spec */
161 timeouttv.tv_usec = 0;
162 } else {
163 /* compute timeout using microseconds per tick */
164 tmo = (Timeout * 1000) / (1000000 / hz);
165 if (tmo <= 0)
166 tmo = 1;
167 timeouttv.tv_sec = Timeout / 1000;
168 timeouttv.tv_usec = (Timeout % 1000) * 1000;
169 }
170
171 /* calculate timeout value in timeval */
172 getmicrouptime(¤ttv);
173 timevaladd(&timeouttv, ¤ttv);
174
175 AS_LOCK(as);
176 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
177 "get %d units from semaphore %p (has %d), timeout %d\n",
178 Units, as, as->as_units, Timeout));
179 for (;;) {
180 if (as->as_maxunits == ACPI_NO_UNIT_LIMIT) {
181 result = AE_OK;
182 break;
183 }
184 if (as->as_units >= Units) {
185 as->as_units -= Units;
186 result = AE_OK;
187 break;
188 }
189
190 /* limit number of pending treads */
191 if (as->as_pendings >= ACPI_SEMAPHORES_MAX_PENDING) {
192 result = AE_TIME;
193 break;
194 }
195
196 /* if timeout values of zero is specified, return immediately */
197 if (Timeout == 0) {
198 result = AE_TIME;
199 break;
200 }
201
202 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
203 "semaphore blocked, calling ssleep(%p, %p, %d, \"acsem\", %d)\n",
204 as, &as->as_spin, PCATCH, tmo));
205
206 as->as_pendings++;
207
208 if (acpi_semaphore_debug) {
209 kprintf("%s: Sleep %jd, pending %jd, semaphore %p, thread %#jx\n",
210 __func__, (intmax_t)Timeout,
211 (intmax_t)as->as_pendings, as,
212 (uintmax_t)AcpiOsGetThreadId());
213 }
214
215 rv = ssleep(as, &as->as_spin, PCATCH, "acsem", tmo);
216
217 as->as_pendings--;
218
219 #if 0
220 if (as->as_resetting) {
221 /* semaphore reset, return immediately */
222 if (as->as_pendings == 0) {
223 as->as_resetting = 0;
224 }
225 result = AE_TIME;
226 break;
227 }
228 #endif
229
230 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "ssleep(%d) returned %d\n", tmo, rv));
231 if (rv == EWOULDBLOCK) {
232 result = AE_TIME;
233 break;
234 }
235
236 /* check if we already awaited enough */
237 timelefttv = timeouttv;
238 getmicrouptime(¤ttv);
239 timevalsub(&timelefttv, ¤ttv);
240 if (timelefttv.tv_sec < 0) {
241 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "await semaphore %p timeout\n",
242 as));
243 result = AE_TIME;
244 break;
245 }
246
247 /* adjust timeout for the next sleep */
248 tmo = (timelefttv.tv_sec * 1000000 + timelefttv.tv_usec) /
249 (1000000 / hz);
250 if (tmo <= 0)
251 tmo = 1;
252
253 if (acpi_semaphore_debug) {
254 kprintf("%s: Wakeup timeleft(%ju, %ju), tmo %ju, sem %p, thread %#jx\n",
255 __func__,
256 (intmax_t)timelefttv.tv_sec, (intmax_t)timelefttv.tv_usec,
257 (intmax_t)tmo, as, (uintmax_t)AcpiOsGetThreadId());
258 }
259 }
260
261 if (acpi_semaphore_debug) {
262 if (result == AE_TIME && Timeout > 0) {
263 kprintf("%s: Timeout %d, pending %d, semaphore %p\n",
264 __func__, Timeout, as->as_pendings, as);
265 }
266 if (ACPI_SUCCESS(result) &&
267 (as->as_timeouts > 0 || as->as_pendings > 0))
268 {
269 kprintf("%s: Acquire %d, units %d, pending %d, sem %p, thread %#jx\n",
270 __func__, Units, as->as_units, as->as_pendings, as,
271 (uintmax_t)AcpiOsGetThreadId());
272 }
273 }
274
275 if (result == AE_TIME)
276 as->as_timeouts++;
277 else
278 as->as_timeouts = 0;
279
280 AS_UNLOCK(as);
281 return_ACPI_STATUS (result);
282 }
283
284 ACPI_STATUS
AcpiOsSignalSemaphore(ACPI_HANDLE Handle,UINT32 Units)285 AcpiOsSignalSemaphore(ACPI_HANDLE Handle, UINT32 Units)
286 {
287 struct acpi_semaphore *as = (struct acpi_semaphore *)Handle;
288 AS_LOCK_DECL;
289
290 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
291
292 if (as == NULL)
293 return_ACPI_STATUS(AE_BAD_PARAMETER);
294
295 AS_LOCK(as);
296 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
297 "return %d units to semaphore %p (has %d)\n",
298 Units, as, as->as_units));
299 if (as->as_maxunits != ACPI_NO_UNIT_LIMIT) {
300 as->as_units += Units;
301 if (as->as_units > as->as_maxunits)
302 as->as_units = as->as_maxunits;
303 }
304
305 if (acpi_semaphore_debug && (as->as_timeouts > 0 || as->as_pendings > 0)) {
306 kprintf("%s: Release %d, units %d, pending %d, semaphore %p, thread %#jx\n",
307 __func__, Units, as->as_units, as->as_pendings, as,
308 (uintmax_t)AcpiOsGetThreadId());
309 }
310
311 wakeup(as);
312 AS_UNLOCK(as);
313
314 return_ACPI_STATUS (AE_OK);
315 }
316
317 /*
318 * This represents a bit of a problem, it looks like the ACPI contrib
319 * code holds Os locks across potentially blocking system calls. So
320 * we can't safely use spinlocks in all situations. But any use-cases
321 * from the idle thread have to use spinlocks.
322 *
323 * For now use the spinlock for idlethread operation and the lockmgr lock
324 * otherwise. The only thing the idlethread can issue ACPI-wise is related
325 * to cpu low power modes, hopefully this will not interfere with ACPI
326 * operations on other cpus on other threads.
327 */
328 struct acpi_spinlock {
329 struct lock lock;
330 struct spinlock slock;
331 #ifdef ACPI_DEBUG_LOCKS
332 thread_t owner;
333 const char *func;
334 int line;
335 #endif
336 };
337
338 ACPI_STATUS
AcpiOsCreateLock(ACPI_SPINLOCK * OutHandle)339 AcpiOsCreateLock(ACPI_SPINLOCK *OutHandle)
340 {
341 ACPI_SPINLOCK spin;
342
343 if (OutHandle == NULL)
344 return (AE_BAD_PARAMETER);
345 spin = kmalloc(sizeof(*spin), M_ACPISEM, M_INTWAIT|M_ZERO);
346 spin_init(&spin->slock, "AcpiOsLock");
347 lockinit(&spin->lock, "AcpiOsLock", 0, 0);
348 #ifdef ACPI_DEBUG_LOCKS
349 spin->owner = NULL;
350 spin->func = "";
351 spin->line = 0;
352 #endif
353 *OutHandle = spin;
354 return (AE_OK);
355 }
356
357 void
AcpiOsDeleteLock(ACPI_SPINLOCK Spin)358 AcpiOsDeleteLock (ACPI_SPINLOCK Spin)
359 {
360 if (Spin == NULL)
361 return;
362 spin_uninit(&Spin->slock);
363 lockuninit(&Spin->lock);
364 kfree(Spin, M_ACPISEM);
365 }
366
367 /*
368 * OS-dependent locking primitives. These routines should be able to be
369 * called from an interrupt-handler or cpu_idle thread.
370 *
371 * NB: some of ACPICA functions with locking flags, say AcpiSetRegister(),
372 * are changed to unconditionally call AcpiOsAcquireLock/AcpiOsReleaseLock.
373 */
374 ACPI_CPU_FLAGS
375 #ifdef ACPI_DEBUG_LOCKS
_AcpiOsAcquireLock(ACPI_SPINLOCK Spin,const char * func,int line)376 _AcpiOsAcquireLock (ACPI_SPINLOCK Spin, const char *func, int line)
377 #else
378 AcpiOsAcquireLock (ACPI_SPINLOCK Spin)
379 #endif
380 {
381 globaldata_t gd = mycpu;
382
383 if (gd->gd_curthread == &gd->gd_idlethread) {
384 spin_lock(&Spin->slock);
385 } else {
386 lockmgr(&Spin->lock, LK_EXCLUSIVE);
387 crit_enter();
388 }
389
390 #ifdef ACPI_DEBUG_LOCKS
391 if (Spin->owner) {
392 kprintf("%p(%s:%d): acpi_spinlock %p already held by %p(%s:%d)\n",
393 curthread, func, line, Spin, Spin->owner, Spin->func,
394 Spin->line);
395 print_backtrace(-1);
396 } else {
397 Spin->owner = curthread;
398 Spin->func = func;
399 Spin->line = line;
400 }
401 #endif
402 return(0);
403 }
404
405 void
AcpiOsReleaseLock(ACPI_SPINLOCK Spin,ACPI_CPU_FLAGS Flags)406 AcpiOsReleaseLock (ACPI_SPINLOCK Spin, ACPI_CPU_FLAGS Flags)
407 {
408 #ifdef ACPI_DEBUG_LOCKS
409 if (Flags) {
410 if (Spin->owner != NULL) {
411 kprintf("%p: acpi_spinlock %p is unexectedly held by %p(%s:%d)\n",
412 curthread, Spin, Spin->owner, Spin->func, Spin->line);
413 print_backtrace(-1);
414 } else
415 return;
416 }
417 Spin->owner = NULL;
418 Spin->func = "";
419 Spin->line = 0;
420 #endif
421 globaldata_t gd = mycpu;
422
423 if (gd->gd_curthread == &gd->gd_idlethread) {
424 spin_unlock(&Spin->slock);
425 } else {
426 crit_exit();
427 lockmgr(&Spin->lock, LK_RELEASE);
428 }
429 }
430
431 /* Section 5.2.9.1: global lock acquire/release functions */
432 #define GL_ACQUIRED (-1)
433 #define GL_BUSY 0
434 #define GL_BIT_PENDING 0x1
435 #define GL_BIT_OWNED 0x2
436 #define GL_BIT_MASK (GL_BIT_PENDING | GL_BIT_OWNED)
437
438 /*
439 * Acquire the global lock. If busy, set the pending bit. The caller
440 * will wait for notification from the BIOS that the lock is available
441 * and then attempt to acquire it again.
442 */
443 int
acpi_acquire_global_lock(uint32_t * lock)444 acpi_acquire_global_lock(uint32_t *lock)
445 {
446 uint32_t new, old;
447
448 do {
449 old = *lock;
450 new = ((old & ~GL_BIT_MASK) | GL_BIT_OWNED) |
451 ((old >> 1) & GL_BIT_PENDING);
452 } while (atomic_cmpset_int(lock, old, new) == 0);
453
454 return ((new < GL_BIT_MASK) ? GL_ACQUIRED : GL_BUSY);
455 }
456
457 /*
458 * Release the global lock, returning whether there is a waiter pending.
459 * If the BIOS set the pending bit, OSPM must notify the BIOS when it
460 * releases the lock.
461 */
462 int
acpi_release_global_lock(uint32_t * lock)463 acpi_release_global_lock(uint32_t *lock)
464 {
465 uint32_t new, old;
466
467 do {
468 old = *lock;
469 new = old & ~GL_BIT_MASK;
470 } while (atomic_cmpset_int(lock, old, new) == 0);
471
472 return (old & GL_BIT_PENDING);
473 }
474