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/5.1/sys/dev/acpica/Osd/OsdSynch.c 107328 2002-11-27 18:09:20Z iwasaki $
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 #if __FreeBSD_version >= 500000
41 #include <sys/lock.h>
42 #include <sys/mutex.h>
43 #endif
44
45 #define _COMPONENT ACPI_OS_SERVICES
46 ACPI_MODULE_NAME("SYNCH")
47
48 static MALLOC_DEFINE(M_ACPISEM, "acpisem", "ACPI semaphore");
49
50 #if __FreeBSD_version < 500000
51 # define AS_LOCK(as) s = splhigh()
52 # define AS_UNLOCK(as) splx(s)
53 # define AS_LOCK_DECL int s
54 # define msleep(a, b, c, d, e) tsleep(a, c, d, e)
55 #else
56 # define AS_LOCK(as) mtx_lock(&(as)->as_mtx)
57 # define AS_UNLOCK(as) mtx_unlock(&(as)->as_mtx)
58 # define AS_LOCK_DECL
59 #endif
60
61 /*
62 * Simple counting semaphore implemented using a mutex. (Subsequently used
63 * in the OSI code to implement a mutex. Go figure.)
64 */
65 struct acpi_semaphore {
66 #if __FreeBSD_version >= 500000
67 struct mtx as_mtx;
68 #endif
69 UINT32 as_units;
70 UINT32 as_maxunits;
71 UINT32 as_pendings;
72 UINT32 as_resetting;
73 UINT32 as_timeouts;
74 };
75
76 #ifndef ACPI_NO_SEMAPHORES
77 #ifndef ACPI_SEMAPHORES_MAX_PENDING
78 #define ACPI_SEMAPHORES_MAX_PENDING 4
79 #endif
80 static int acpi_semaphore_debug = 0;
81 TUNABLE_INT("debug.acpi_semaphore_debug", &acpi_semaphore_debug);
82 SYSCTL_INT(_debug, OID_AUTO, acpi_semaphore_debug, CTLFLAG_RW,
83 &acpi_semaphore_debug, 0, "");
84 #endif
85
86 ACPI_STATUS
87 AcpiOsCreateSemaphore(UINT32 MaxUnits, UINT32 InitialUnits, ACPI_HANDLE *OutHandle)
88 {
89 #ifndef ACPI_NO_SEMAPHORES
90 struct acpi_semaphore *as;
91
92 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
93
94 if (OutHandle == NULL)
95 return(AE_BAD_PARAMETER);
96 if (InitialUnits > MaxUnits)
97 return_ACPI_STATUS(AE_BAD_PARAMETER);
98
99 if ((as = malloc(sizeof(*as), M_ACPISEM, M_NOWAIT)) == NULL)
100 return_ACPI_STATUS(AE_NO_MEMORY);
101
102 bzero(as, sizeof(*as));
103 #if __FreeBSD_version >= 500000
104 mtx_init(&as->as_mtx, "ACPI semaphore", NULL, MTX_DEF);
105 #endif
106 as->as_units = InitialUnits;
107 as->as_maxunits = MaxUnits;
108 as->as_pendings = as->as_resetting = as->as_timeouts = 0;
109
110 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
111 "created semaphore %p max %d, initial %d\n",
112 as, InitialUnits, MaxUnits));
113
114 *OutHandle = (ACPI_HANDLE)as;
115 return_ACPI_STATUS(AE_OK);
116 #else
117 *OutHandle = (ACPI_HANDLE)OutHandle;
118 return(AE_OK);
119 #endif
120 }
121
122 ACPI_STATUS
123 AcpiOsDeleteSemaphore (ACPI_HANDLE Handle)
124 {
125 #ifndef ACPI_NO_SEMAPHORES
126 struct acpi_semaphore *as = (struct acpi_semaphore *)Handle;
127
128 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
129
130 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "destroyed semaphore %p\n", as));
131 #if __FreeBSD_version >= 500000
132 mtx_destroy(&as->as_mtx);
133 #endif
134 free(Handle, M_ACPISEM);
135 return_ACPI_STATUS(AE_OK);
136 #else
137 return(AE_OK);
138 #endif
139 }
140
141 /*
142 * This implementation has a bug, in that it has to stall for the entire
143 * timeout before it will return AE_TIME. A better implementation would
144 * use getmicrotime() to correctly adjust the timeout after being woken up.
145 */
146 ACPI_STATUS
147 AcpiOsWaitSemaphore(ACPI_HANDLE Handle, UINT32 Units, UINT16 Timeout)
148 {
149 #ifndef ACPI_NO_SEMAPHORES
150 struct acpi_semaphore *as = (struct acpi_semaphore *)Handle;
151 ACPI_STATUS result;
152 int rv, tmo;
153 struct timeval timeouttv, currenttv, timelefttv;
154 AS_LOCK_DECL;
155
156 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
157
158 if (as == NULL)
159 return_ACPI_STATUS(AE_BAD_PARAMETER);
160
161 if (cold)
162 return_ACPI_STATUS(AE_OK);
163
164 #if 0
165 if (as->as_units < Units && as->as_timeouts > 10) {
166 printf("%s: semaphore %p too many timeouts, resetting\n", __func__, as);
167 AS_LOCK(as);
168 as->as_units = as->as_maxunits;
169 if (as->as_pendings)
170 as->as_resetting = 1;
171 as->as_timeouts = 0;
172 wakeup(as);
173 AS_UNLOCK(as);
174 return_ACPI_STATUS(AE_TIME);
175 }
176
177 if (as->as_resetting) {
178 return_ACPI_STATUS(AE_TIME);
179 }
180 #endif
181
182 /* a timeout of ACPI_WAIT_FOREVER means "forever" */
183 if (Timeout == ACPI_WAIT_FOREVER) {
184 tmo = 0;
185 timeouttv.tv_sec = ((0xffff/1000) + 1); /* cf. ACPI spec */
186 timeouttv.tv_usec = 0;
187 } else {
188 /* compute timeout using microseconds per tick */
189 tmo = (Timeout * 1000) / (1000000 / hz);
190 if (tmo <= 0)
191 tmo = 1;
192 timeouttv.tv_sec = Timeout / 1000;
193 timeouttv.tv_usec = (Timeout % 1000) * 1000;
194 }
195
196 /* calculate timeout value in timeval */
197 getmicrotime(¤ttv);
198 timevaladd(&timeouttv, ¤ttv);
199
200 AS_LOCK(as);
201 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
202 "get %d units from semaphore %p (has %d), timeout %d\n",
203 Units, as, as->as_units, Timeout));
204 for (;;) {
205 if (as->as_maxunits == ACPI_NO_UNIT_LIMIT) {
206 result = AE_OK;
207 break;
208 }
209 if (as->as_units >= Units) {
210 as->as_units -= Units;
211 result = AE_OK;
212 break;
213 }
214
215 /* limit number of pending treads */
216 if (as->as_pendings >= ACPI_SEMAPHORES_MAX_PENDING) {
217 result = AE_TIME;
218 break;
219 }
220
221 /* if timeout values of zero is specified, return immediately */
222 if (Timeout == 0) {
223 result = AE_TIME;
224 break;
225 }
226
227 #if __FreeBSD_version >= 500000
228 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
229 "semaphore blocked, calling msleep(%p, %p, %d, \"acsem\", %d)\n",
230 as, &as->as_mtx, PCATCH, tmo));
231 #endif
232
233 as->as_pendings++;
234
235 if (acpi_semaphore_debug) {
236 printf("%s: Sleep %d, pending %d, semaphore %p, thread %d\n",
237 __func__, Timeout, as->as_pendings, as, AcpiOsGetThreadId());
238 }
239
240 rv = msleep(as, &as->as_mtx, PCATCH, "acsem", tmo);
241
242 as->as_pendings--;
243
244 #if 0
245 if (as->as_resetting) {
246 /* semaphore reset, return immediately */
247 if (as->as_pendings == 0) {
248 as->as_resetting = 0;
249 }
250 result = AE_TIME;
251 break;
252 }
253 #endif
254
255 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "msleep(%d) returned %d\n", tmo, rv));
256 if (rv == EWOULDBLOCK) {
257 result = AE_TIME;
258 break;
259 }
260
261 /* check if we already awaited enough */
262 timelefttv = timeouttv;
263 getmicrotime(¤ttv);
264 timevalsub(&timelefttv, ¤ttv);
265 if (timelefttv.tv_sec < 0) {
266 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "await semaphore %p timeout\n", as));
267 result = AE_TIME;
268 break;
269 }
270
271 /* adjust timeout for the next sleep */
272 tmo = (timelefttv.tv_sec * 1000000 + timelefttv.tv_usec) / (1000000 / hz);
273 if (tmo <= 0)
274 tmo = 1;
275
276 if (acpi_semaphore_debug) {
277 printf("%s: Wakeup timeleft(%lu, %lu), tmo %u, semaphore %p, thread %d\n",
278 __func__, timelefttv.tv_sec, timelefttv.tv_usec, tmo, as, AcpiOsGetThreadId());
279 }
280 }
281
282 if (acpi_semaphore_debug) {
283 if (result == AE_TIME && Timeout > 0) {
284 printf("%s: Timeout %d, pending %d, semaphore %p\n",
285 __func__, Timeout, as->as_pendings, as);
286 }
287 if (result == AE_OK && (as->as_timeouts > 0 || as->as_pendings > 0)) {
288 printf("%s: Acquire %d, units %d, pending %d, semaphore %p, thread %d\n",
289 __func__, Units, as->as_units, as->as_pendings, as, AcpiOsGetThreadId());
290 }
291 }
292
293 if (result == AE_TIME) {
294 as->as_timeouts++;
295 } else {
296 as->as_timeouts = 0;
297 }
298
299 AS_UNLOCK(as);
300
301 return_ACPI_STATUS(result);
302 #else
303 return(AE_OK);
304 #endif
305 }
306
307 ACPI_STATUS
308 AcpiOsSignalSemaphore(ACPI_HANDLE Handle, UINT32 Units)
309 {
310 #ifndef ACPI_NO_SEMAPHORES
311 struct acpi_semaphore *as = (struct acpi_semaphore *)Handle;
312 AS_LOCK_DECL;
313
314 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
315
316 if (as == NULL)
317 return_ACPI_STATUS(AE_BAD_PARAMETER);
318
319 AS_LOCK(as);
320 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
321 "return %d units to semaphore %p (has %d)\n",
322 Units, as, as->as_units));
323 if (as->as_maxunits != ACPI_NO_UNIT_LIMIT) {
324 as->as_units += Units;
325 if (as->as_units > as->as_maxunits)
326 as->as_units = as->as_maxunits;
327 }
328
329 if (acpi_semaphore_debug && (as->as_timeouts > 0 || as->as_pendings > 0)) {
330 printf("%s: Release %d, units %d, pending %d, semaphore %p, thread %d\n",
331 __func__, Units, as->as_units, as->as_pendings, as, AcpiOsGetThreadId());
332 }
333
334 wakeup(as);
335 AS_UNLOCK(as);
336 return_ACPI_STATUS(AE_OK);
337 #else
338 return(AE_OK);
339 #endif
340 }
Cache object: d68115089d3eb86eb783f41f05f8ced2
|