OsdSynch.c revision 74914 
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 74914 2001-03-28 09:17:56Z jhb $
28 */
29
30/*
31 * 6.1 : Mutual Exclusion and Synchronisation
32 */
33
34#include "acpi.h"
35
36#include <sys/kernel.h>
37#include <sys/lock.h>
38#include <sys/malloc.h>
39#include <sys/mutex.h>
40
41#define _COMPONENT	OS_DEPENDENT
42MODULE_NAME("SYNCH")
43
44static MALLOC_DEFINE(M_ACPISEM, "acpisem", "ACPI semaphore");
45
46/* disable semaphores - AML in the field doesn't use them correctly */
47#define ACPI_NO_SEMAPHORES
48
49/*
50 * Simple counting semaphore implemented using a mutex. (Subsequently used
51 * in the OSI code to implement a mutex.  Go figure.)
52 */
53struct acpi_semaphore {
54    struct mtx	as_mtx;
55    UINT32	as_units;
56    UINT32	as_maxunits;
57    char	*as_name;
58};
59
60ACPI_STATUS
61AcpiOsCreateSemaphore(UINT32 MaxUnits, UINT32 InitialUnits, ACPI_HANDLE *OutHandle)
62{
63#ifndef ACPI_NO_SEMAPHORES
64    struct acpi_semaphore	*as;
65
66    FUNCTION_TRACE(__FUNCTION__);
67
68    if (OutHandle == NULL)
69	return(AE_BAD_PARAMETER);
70    if (InitialUnits > MaxUnits)
71	return_ACPI_STATUS(AE_BAD_PARAMETER);
72
73    if ((as = malloc(sizeof(*as), M_ACPISEM, M_NOWAIT)) == NULL)
74	return_ACPI_STATUS(AE_NO_MEMORY);
75
76    mtx_init(&as->as_mtx, "ACPI semaphore", MTX_DEF);
77    as->as_units = InitialUnits;
78    as->as_maxunits = MaxUnits;
79    as->as_name = malloc(strlen(name) + 1, M_ACPISEM, M_NOWAIT);
80    strcpy(as->as_name, name);
81
82    DEBUG_PRINT(TRACE_MUTEX, ("created semaphore %p max %d, initial %d\n",
83			      as, InitialUnits, MaxUnits));
84
85    *OutHandle = (ACPI_HANDLE)as;
86    return_ACPI_STATUS(AE_OK);
87#else
88    *OutHandle = (ACPI_HANDLE)OutHandle;
89    return(AE_OK);
90#endif
91}
92
93ACPI_STATUS
94AcpiOsDeleteSemaphore (ACPI_HANDLE Handle)
95{
96#ifndef ACPI_NO_SEMAPHORES
97    struct acpi_semaphore *as = (struct acpi_semaphore *)Handle;
98
99    FUNCTION_TRACE(__FUNCTION__);
100
101#ifdef ACPI_TRACK_SEMAPHORE
102    printf("destroyed semaphore '%s' @ %p\n", as->as_name, as);
103#else
104    DEBUG_PRINT(TRACE_MUTEX, ("destroyed semaphore %p\n", as));
105#endif
106    mtx_destroy(&as->as_mtx);
107    free(as->as_name, M_ACPISEM);
108    free(Handle, M_ACPISEM);
109    return_ACPI_STATUS(AE_OK);
110#else
111    return(AE_OK);
112#endif
113}
114
115/*
116 * This implementation has a bug, in that it has to stall for the entire
117 * timeout before it will return AE_TIME.  A better implementation would
118 * use getmicrotime() to correctly adjust the timeout after being woken up.
119 */
120ACPI_STATUS
121AcpiOsWaitSemaphore(ACPI_HANDLE Handle, UINT32 Units, UINT32 Timeout)
122{
123#ifndef ACPI_NO_SEMAPHORES
124    struct acpi_semaphore	*as = (struct acpi_semaphore *)Handle;
125    ACPI_STATUS			result;
126    int				rv, tmo;
127
128    FUNCTION_TRACE(__FUNCTION__);
129
130    if (as == NULL)
131	return_ACPI_STATUS(AE_BAD_PARAMETER);
132
133    /* a timeout of -1 means "forever" */
134    if (Timeout == -1) {
135	tmo = 0;
136    } else {
137	/* compute timeout using microseconds per tick */
138	tmo = (Timeout * 1000) / (1000000 / hz)
139	if (tmo <= 0)
140	    tmo = 1;
141    }
142
143    mtx_lock(&as->as_mtx);
144    DEBUG_PRINT(TRACE_MUTEX, ("get %d units from semaphore %p (has %d), timeout %d\n",
145			      Units, as, as->as_units, Timeout));
146    for (;;) {
147	if (as->as_units >= Units) {
148	    as->as_units -= Units;
149	    result = AE_OK;
150	    break;
151	}
152	if (Timeout < 0) {
153	    result = AE_TIME;
154	    break;
155	}
156	DEBUG_PRINT(TRACE_MUTEX, ("semaphore blocked, calling msleep(%p, %p, %d, \"acpisem\", %d)\n",
157				  as, as->as_mtx, 0, tmo));
158	for (;;) ;
159
160	rv = msleep(as, &as->as_mtx, 0, "acpisem", tmo);
161	DEBUG_PRINT(TRACE_MUTEX, ("msleep returned %d\n", rv));
162	if (rv == EWOULDBLOCK) {
163	    result = AE_TIME;
164	    break;
165	}
166    }
167    mtx_unlock(&as->as_mtx);
168
169    return_ACPI_STATUS(result);
170#else
171    return(AE_OK);
172#endif
173}
174
175ACPI_STATUS
176AcpiOsSignalSemaphore(ACPI_HANDLE Handle, UINT32 Units)
177{
178#ifndef ACPI_NO_SEMAPHORES
179    struct acpi_semaphore	*as = (struct acpi_semaphore *)Handle;
180
181    FUNCTION_TRACE(__FUNCTION__);
182
183    if (as == NULL)
184	return_ACPI_STATUS(AE_BAD_PARAMETER);
185
186    mtx_lock(&as->as_mtx);
187    DEBUG_PRINT(TRACE_MUTEX, ("return %d units to semaphore %p (has %d)\n",
188			      Units, as, as->as_units));
189    as->as_units += Units;
190    if (as->as_units > as->as_maxunits)
191	as->as_units = as->as_maxunits;
192    wakeup(as);
193    mtx_unlock(&as->as_mtx);
194    return_ACPI_STATUS(AE_OK);
195#else
196    return(AE_OK);
197#endif
198}
199