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: releng/5.3/sys/dev/acpica/Osd/OsdSynch.c 130695 2004-06-18 17:58:11Z njl $
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 }
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