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: head/sys/dev/acpica/Osd/OsdSynch.c 99492 2002-07-06 13:59:59Z 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/lock.h>
39#include <sys/malloc.h>
40#include <sys/mutex.h>
41#include <sys/sysctl.h>
42
43#define _COMPONENT ACPI_OS_SERVICES
44ACPI_MODULE_NAME("SYNCH")
45
46static MALLOC_DEFINE(M_ACPISEM, "acpisem", "ACPI semaphore");
47
48/*
49 * Simple counting semaphore implemented using a mutex. (Subsequently used
50 * in the OSI code to implement a mutex. Go figure.)
51 */
52struct acpi_semaphore {
53 struct mtx as_mtx;
54 UINT32 as_units;
55 UINT32 as_maxunits;
56 UINT32 as_pendings;
57 UINT32 as_resetting;
58 UINT32 as_timeouts;
59};
60
61#ifndef ACPI_NO_SEMAPHORES
62#ifndef ACPI_SEMAPHORES_MAX_PENDING
63#define ACPI_SEMAPHORES_MAX_PENDING 4
64#endif
65static int acpi_semaphore_debug = 0;
66TUNABLE_INT("debug.acpi_semaphore_debug", &acpi_semaphore_debug);
67SYSCTL_INT(_debug, OID_AUTO, acpi_semaphore_debug, CTLFLAG_RW,
68 &acpi_semaphore_debug, 0, "");
69#endif
70
71ACPI_STATUS
72AcpiOsCreateSemaphore(UINT32 MaxUnits, UINT32 InitialUnits, ACPI_HANDLE *OutHandle)
73{
74#ifndef ACPI_NO_SEMAPHORES
75 struct acpi_semaphore *as;
76
77 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
78
79 if (OutHandle == NULL)
80 return(AE_BAD_PARAMETER);
81 if (InitialUnits > MaxUnits)
82 return_ACPI_STATUS(AE_BAD_PARAMETER);
83
84 if ((as = malloc(sizeof(*as), M_ACPISEM, M_NOWAIT)) == NULL)
85 return_ACPI_STATUS(AE_NO_MEMORY);
86
87 bzero(as, sizeof(*as));
88 mtx_init(&as->as_mtx, "ACPI semaphore", NULL, MTX_DEF);
89 as->as_units = InitialUnits;
90 as->as_maxunits = MaxUnits;
91 as->as_pendings = as->as_resetting = as->as_timeouts = 0;
92
93 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
94 "created semaphore %p max %d, initial %d\n",
95 as, InitialUnits, MaxUnits));
96
97 *OutHandle = (ACPI_HANDLE)as;
98 return_ACPI_STATUS(AE_OK);
99#else
100 *OutHandle = (ACPI_HANDLE)OutHandle;
101 return(AE_OK);
102#endif
103}
104
105ACPI_STATUS
106AcpiOsDeleteSemaphore (ACPI_HANDLE Handle)
107{
108#ifndef ACPI_NO_SEMAPHORES
109 struct acpi_semaphore *as = (struct acpi_semaphore *)Handle;
110
111 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
112
113 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "destroyed semaphore %p\n", as));
114 mtx_destroy(&as->as_mtx);
115 free(Handle, M_ACPISEM);
116 return_ACPI_STATUS(AE_OK);
117#else
118 return(AE_OK);
119#endif
120}
121
122/*
123 * This implementation has a bug, in that it has to stall for the entire
124 * timeout before it will return AE_TIME. A better implementation would
125 * use getmicrotime() to correctly adjust the timeout after being woken up.
126 */
127ACPI_STATUS
128AcpiOsWaitSemaphore(ACPI_HANDLE Handle, UINT32 Units, UINT32 Timeout)
129{
130#ifndef ACPI_NO_SEMAPHORES
131 struct acpi_semaphore *as = (struct acpi_semaphore *)Handle;
132 ACPI_STATUS result;
133 int rv, tmo;
134 struct timeval timeouttv, currenttv, timelefttv;
135
136 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
137
138 if (as == NULL)
139 return_ACPI_STATUS(AE_BAD_PARAMETER);
140
141 if (cold)
142 return_ACPI_STATUS(AE_OK);
143
144#if 0
145 if (as->as_units < Units && as->as_timeouts > 10) {
146 printf("%s: semaphore %p too many timeouts, resetting\n", __func__, as);
147 mtx_lock(&as->as_mtx);
148 as->as_units = as->as_maxunits;
149 if (as->as_pendings)
150 as->as_resetting = 1;
151 as->as_timeouts = 0;
152 wakeup(as);
153 mtx_unlock(&as->as_mtx);
154 return_ACPI_STATUS(AE_TIME);
155 }
156
157 if (as->as_resetting) {
158 return_ACPI_STATUS(AE_TIME);
159 }
160#endif
161
162 /* a timeout of WAIT_FOREVER means "forever" */
163 if (Timeout == WAIT_FOREVER) {
164 tmo = 0;
165 timeouttv.tv_sec = ((0xffff/1000) + 1); /* cf. ACPI spec */
166 timeouttv.tv_usec = 0;
167 } else {
168 /* compute timeout using microseconds per tick */
169 tmo = (Timeout * 1000) / (1000000 / hz);
170 if (tmo <= 0)
171 tmo = 1;
172 timeouttv.tv_sec = Timeout / 1000;
173 timeouttv.tv_usec = (Timeout % 1000) * 1000;
174 }
175
176 /* calculate timeout value in timeval */
177 getmicrotime(&currenttv);
178 timevaladd(&timeouttv, &currenttv);
179
180 mtx_lock(&as->as_mtx);
181 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
182 "get %d units from semaphore %p (has %d), timeout %d\n",
183 Units, as, as->as_units, Timeout));
184 for (;;) {
185 if (as->as_maxunits == ACPI_NO_UNIT_LIMIT) {
186 result = AE_OK;
187 break;
188 }
189 if (as->as_units >= Units) {
190 as->as_units -= Units;
191 result = AE_OK;
192 break;
193 }
194
195 /* limit number of pending treads */
196 if (as->as_pendings >= ACPI_SEMAPHORES_MAX_PENDING) {
197 result = AE_TIME;
198 break;
199 }
200
201 /* if timeout values of zero is specified, return immediately */
202 if (Timeout == 0) {
203 result = AE_TIME;
204 break;
205 }
206
207 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
208 "semaphore blocked, calling msleep(%p, %p, %d, \"acsem\", %d)\n",
209 as, &as->as_mtx, PCATCH, tmo));
210
211 as->as_pendings++;
212
213 if (acpi_semaphore_debug) {
214 printf("%s: Sleep %d, pending %d, semaphore %p, thread %d\n",
215 __func__, Timeout, as->as_pendings, as, AcpiOsGetThreadId());
216 }
217
218 rv = msleep(as, &as->as_mtx, PCATCH, "acsem", tmo);
219
220 as->as_pendings--;
221
222#if 0
223 if (as->as_resetting) {
224 /* semaphore reset, return immediately */
225 if (as->as_pendings == 0) {
226 as->as_resetting = 0;
227 }
228 result = AE_TIME;
229 break;
230 }
231#endif
232
233 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "msleep(%d) returned %d\n", tmo, rv));
234 if (rv == EWOULDBLOCK) {
235 result = AE_TIME;
236 break;
237 }
238
239 /* check if we already awaited enough */
240 timelefttv = timeouttv;
241 getmicrotime(&currenttv);
242 timevalsub(&timelefttv, &currenttv);
243 if (timelefttv.tv_sec < 0) {
244 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "await semaphore %p timeout\n", as));
245 result = AE_TIME;
246 break;
247 }
248
249 /* adjust timeout for the next sleep */
250 tmo = (timelefttv.tv_sec * 1000000 + timelefttv.tv_usec) / (1000000 / hz);
251 if (tmo <= 0)
252 tmo = 1;
253
254 if (acpi_semaphore_debug) {
255 printf("%s: Wakeup timeleft(%lu, %lu), tmo %u, semaphore %p, thread %d\n",
256 __func__, timelefttv.tv_sec, timelefttv.tv_usec, tmo, as, AcpiOsGetThreadId());
257 }
258 }
259
260 if (acpi_semaphore_debug) {
261 if (result == AE_TIME && Timeout > 0) {
262 printf("%s: Timeout %d, pending %d, semaphore %p\n",
263 __func__, Timeout, as->as_pendings, as);
264 }
265 if (result == AE_OK && (as->as_timeouts > 0 || as->as_pendings > 0)) {
266 printf("%s: Acquire %d, units %d, pending %d, semaphore %p, thread %d\n",
267 __func__, Units, as->as_units, as->as_pendings, as, AcpiOsGetThreadId());
268 }
269 }
270
271 if (result == AE_TIME) {
272 as->as_timeouts++;
273 } else {
274 as->as_timeouts = 0;
275 }
276
277 mtx_unlock(&as->as_mtx);
278
279 return_ACPI_STATUS(result);
280#else
281 return(AE_OK);
282#endif
283}
284
285ACPI_STATUS
286AcpiOsSignalSemaphore(ACPI_HANDLE Handle, UINT32 Units)
287{
288#ifndef ACPI_NO_SEMAPHORES
289 struct acpi_semaphore *as = (struct acpi_semaphore *)Handle;
290
291 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
292
293 if (as == NULL)
294 return_ACPI_STATUS(AE_BAD_PARAMETER);
295
296 mtx_lock(&as->as_mtx);
297 ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
298 "return %d units to semaphore %p (has %d)\n",
299 Units, as, as->as_units));
300 if (as->as_maxunits != ACPI_NO_UNIT_LIMIT) {
301 as->as_units += Units;
302 if (as->as_units > as->as_maxunits)
303 as->as_units = as->as_maxunits;
304 }
305
306 if (acpi_semaphore_debug && (as->as_timeouts > 0 || as->as_pendings > 0)) {
307 printf("%s: Release %d, units %d, pending %d, semaphore %p, thread %d\n",
308 __func__, Units, as->as_units, as->as_pendings, as, AcpiOsGetThreadId());
309 }
310
311 wakeup(as);
312 mtx_unlock(&as->as_mtx);
313 return_ACPI_STATUS(AE_OK);
314#else
315 return(AE_OK);
316#endif
317}