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: head/sys/dev/acpica/Osd/OsdSynch.c 153706 2005-12-24 22:22:17Z trhodes $");
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
45ACPI_MODULE_NAME("SYNCH")
46
47MALLOC_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 */
56struct 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
69static int acpi_semaphore_debug = 0;
70TUNABLE_INT("debug.acpi_semaphore_debug", &acpi_semaphore_debug);
71SYSCTL_DECL(_debug_acpi);
72SYSCTL_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
76ACPI_STATUS
77AcpiOsCreateSemaphore(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
110ACPI_STATUS
111AcpiOsDeleteSemaphore(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 */
131ACPI_STATUS
132AcpiOsWaitSemaphore(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(&currenttv);
181 timevaladd(&timeouttv, &currenttv);
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(&currenttv);
245 timevalsub(&timelefttv, &currenttv);
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
290ACPI_STATUS
291AcpiOsSignalSemaphore(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
323ACPI_STATUS
324AcpiOsCreateLock (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
339void
340AcpiOsDeleteLock (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 */
354ACPI_NATIVE_UINT
355AcpiOsAcquireLock (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
365void
366AcpiOsReleaseLock (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 */
387int
388acpi_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 */
406int
407acpi_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}