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/*-
* Copyright (c) 2000 Michael Smith
* Copyright (c) 2000 BSDi
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* 6.1 : Mutual Exclusion and Synchronisation
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "acpi.h"
#include "opt_acpi.h"
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/sysctl.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#define _COMPONENT ACPI_OS_SERVICES
ACPI_MODULE_NAME("SYNCH")
MALLOC_DEFINE(M_ACPISEM, "acpisem", "ACPI semaphore");
#define AS_LOCK(as) mtx_lock(&(as)->as_mtx)
#define AS_UNLOCK(as) mtx_unlock(&(as)->as_mtx)
/*
* Simple counting semaphore implemented using a mutex. (Subsequently used
* in the OSI code to implement a mutex. Go figure.)
*/
struct acpi_semaphore {
struct mtx as_mtx;
UINT32 as_units;
UINT32 as_maxunits;
UINT32 as_pendings;
UINT32 as_resetting;
UINT32 as_timeouts;
};
#ifndef ACPI_NO_SEMAPHORES
#ifndef ACPI_SEMAPHORES_MAX_PENDING
#define ACPI_SEMAPHORES_MAX_PENDING 4
#endif
static int acpi_semaphore_debug = 0;
TUNABLE_INT("debug.acpi_semaphore_debug", &acpi_semaphore_debug);
SYSCTL_DECL(_debug_acpi);
SYSCTL_INT(_debug_acpi, OID_AUTO, semaphore_debug, CTLFLAG_RW,
&acpi_semaphore_debug, 0, "Enable ACPI semaphore debug messages");
#endif /* !ACPI_NO_SEMAPHORES */
ACPI_STATUS
AcpiOsCreateSemaphore(UINT32 MaxUnits, UINT32 InitialUnits,
ACPI_HANDLE *OutHandle)
{
#ifndef ACPI_NO_SEMAPHORES
struct acpi_semaphore *as;
ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
if (OutHandle == NULL)
return_ACPI_STATUS (AE_BAD_PARAMETER);
if (InitialUnits > MaxUnits)
return_ACPI_STATUS (AE_BAD_PARAMETER);
if ((as = malloc(sizeof(*as), M_ACPISEM, M_NOWAIT | M_ZERO)) == NULL)
return_ACPI_STATUS (AE_NO_MEMORY);
mtx_init(&as->as_mtx, "ACPI semaphore", NULL, MTX_DEF);
as->as_units = InitialUnits;
as->as_maxunits = MaxUnits;
as->as_pendings = as->as_resetting = as->as_timeouts = 0;
ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
"created semaphore %p max %d, initial %d\n",
as, InitialUnits, MaxUnits));
*OutHandle = (ACPI_HANDLE)as;
#else
*OutHandle = (ACPI_HANDLE)OutHandle;
#endif /* !ACPI_NO_SEMAPHORES */
return_ACPI_STATUS (AE_OK);
}
ACPI_STATUS
AcpiOsDeleteSemaphore(ACPI_HANDLE Handle)
{
#ifndef ACPI_NO_SEMAPHORES
struct acpi_semaphore *as = (struct acpi_semaphore *)Handle;
ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "destroyed semaphore %p\n", as));
mtx_destroy(&as->as_mtx);
free(Handle, M_ACPISEM);
#endif /* !ACPI_NO_SEMAPHORES */
return_ACPI_STATUS (AE_OK);
}
/*
* This implementation has a bug, in that it has to stall for the entire
* timeout before it will return AE_TIME. A better implementation would
* use getmicrotime() to correctly adjust the timeout after being woken up.
*/
ACPI_STATUS
AcpiOsWaitSemaphore(ACPI_HANDLE Handle, UINT32 Units, UINT16 Timeout)
{
#ifndef ACPI_NO_SEMAPHORES
ACPI_STATUS result;
struct acpi_semaphore *as = (struct acpi_semaphore *)Handle;
int rv, tmo;
struct timeval timeouttv, currenttv, timelefttv;
ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
if (as == NULL)
return_ACPI_STATUS (AE_BAD_PARAMETER);
if (cold)
return_ACPI_STATUS (AE_OK);
#if 0
if (as->as_units < Units && as->as_timeouts > 10) {
printf("%s: semaphore %p too many timeouts, resetting\n", __func__, as);
AS_LOCK(as);
as->as_units = as->as_maxunits;
if (as->as_pendings)
as->as_resetting = 1;
as->as_timeouts = 0;
wakeup(as);
AS_UNLOCK(as);
return_ACPI_STATUS (AE_TIME);
}
if (as->as_resetting)
return_ACPI_STATUS (AE_TIME);
#endif
/* a timeout of ACPI_WAIT_FOREVER means "forever" */
if (Timeout == ACPI_WAIT_FOREVER) {
tmo = 0;
timeouttv.tv_sec = ((0xffff/1000) + 1); /* cf. ACPI spec */
timeouttv.tv_usec = 0;
} else {
/* compute timeout using microseconds per tick */
tmo = (Timeout * 1000) / (1000000 / hz);
if (tmo <= 0)
tmo = 1;
timeouttv.tv_sec = Timeout / 1000;
timeouttv.tv_usec = (Timeout % 1000) * 1000;
}
/* calculate timeout value in timeval */
getmicrotime(¤ttv);
timevaladd(&timeouttv, ¤ttv);
AS_LOCK(as);
ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
"get %d units from semaphore %p (has %d), timeout %d\n",
Units, as, as->as_units, Timeout));
for (;;) {
if (as->as_maxunits == ACPI_NO_UNIT_LIMIT) {
result = AE_OK;
break;
}
if (as->as_units >= Units) {
as->as_units -= Units;
result = AE_OK;
break;
}
/* limit number of pending treads */
if (as->as_pendings >= ACPI_SEMAPHORES_MAX_PENDING) {
result = AE_TIME;
break;
}
/* if timeout values of zero is specified, return immediately */
if (Timeout == 0) {
result = AE_TIME;
break;
}
ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
"semaphore blocked, calling msleep(%p, %p, %d, \"acsem\", %d)\n",
as, &as->as_mtx, PCATCH, tmo));
as->as_pendings++;
if (acpi_semaphore_debug) {
printf("%s: Sleep %d, pending %d, semaphore %p, thread %d\n",
__func__, Timeout, as->as_pendings, as, AcpiOsGetThreadId());
}
rv = msleep(as, &as->as_mtx, PCATCH, "acsem", tmo);
as->as_pendings--;
#if 0
if (as->as_resetting) {
/* semaphore reset, return immediately */
if (as->as_pendings == 0) {
as->as_resetting = 0;
}
result = AE_TIME;
break;
}
#endif
ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "msleep(%d) returned %d\n", tmo, rv));
if (rv == EWOULDBLOCK) {
result = AE_TIME;
break;
}
/* check if we already awaited enough */
timelefttv = timeouttv;
getmicrotime(¤ttv);
timevalsub(&timelefttv, ¤ttv);
if (timelefttv.tv_sec < 0) {
ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "await semaphore %p timeout\n",
as));
result = AE_TIME;
break;
}
/* adjust timeout for the next sleep */
tmo = (timelefttv.tv_sec * 1000000 + timelefttv.tv_usec) /
(1000000 / hz);
if (tmo <= 0)
tmo = 1;
if (acpi_semaphore_debug) {
printf("%s: Wakeup timeleft(%lu, %lu), tmo %u, sem %p, thread %d\n",
__func__, timelefttv.tv_sec, timelefttv.tv_usec, tmo, as,
AcpiOsGetThreadId());
}
}
if (acpi_semaphore_debug) {
if (result == AE_TIME && Timeout > 0) {
printf("%s: Timeout %d, pending %d, semaphore %p\n",
__func__, Timeout, as->as_pendings, as);
}
if (result == AE_OK && (as->as_timeouts > 0 || as->as_pendings > 0)) {
printf("%s: Acquire %d, units %d, pending %d, sem %p, thread %d\n",
__func__, Units, as->as_units, as->as_pendings, as,
AcpiOsGetThreadId());
}
}
if (result == AE_TIME)
as->as_timeouts++;
else
as->as_timeouts = 0;
AS_UNLOCK(as);
return_ACPI_STATUS (result);
#else
return_ACPI_STATUS (AE_OK);
#endif /* !ACPI_NO_SEMAPHORES */
}
ACPI_STATUS
AcpiOsSignalSemaphore(ACPI_HANDLE Handle, UINT32 Units)
{
#ifndef ACPI_NO_SEMAPHORES
struct acpi_semaphore *as = (struct acpi_semaphore *)Handle;
ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
if (as == NULL)
return_ACPI_STATUS(AE_BAD_PARAMETER);
AS_LOCK(as);
ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
"return %d units to semaphore %p (has %d)\n",
Units, as, as->as_units));
if (as->as_maxunits != ACPI_NO_UNIT_LIMIT) {
as->as_units += Units;
if (as->as_units > as->as_maxunits)
as->as_units = as->as_maxunits;
}
if (acpi_semaphore_debug && (as->as_timeouts > 0 || as->as_pendings > 0)) {
printf("%s: Release %d, units %d, pending %d, semaphore %p, thread %d\n",
__func__, Units, as->as_units, as->as_pendings, as, AcpiOsGetThreadId());
}
wakeup(as);
AS_UNLOCK(as);
#endif /* !ACPI_NO_SEMAPHORES */
return_ACPI_STATUS (AE_OK);
}
ACPI_STATUS
AcpiOsCreateLock (ACPI_HANDLE *OutHandle)
{
struct mtx *m;
if (OutHandle == NULL)
return (AE_BAD_PARAMETER);
m = malloc(sizeof(*m), M_ACPISEM, M_NOWAIT | M_ZERO);
if (m == NULL)
return (AE_NO_MEMORY);
mtx_init(m, "acpica subsystem lock", NULL, MTX_DEF);
*OutHandle = (ACPI_HANDLE)m;
return (AE_OK);
}
void
AcpiOsDeleteLock (ACPI_HANDLE Handle)
{
struct mtx *m = (struct mtx *)Handle;
if (Handle == NULL)
return;
mtx_destroy(m);
}
/*
* The Flags parameter seems to state whether or not caller is an ISR
* (and thus can't block) but since we have ithreads, we don't worry
* about potentially blocking.
*/
void
AcpiOsAcquireLock (ACPI_HANDLE Handle, UINT32 Flags)
{
struct mtx *m = (struct mtx *)Handle;
if (Handle == NULL)
return;
mtx_lock(m);
}
void
AcpiOsReleaseLock (ACPI_HANDLE Handle, UINT32 Flags)
{
struct mtx *m = (struct mtx *)Handle;
if (Handle == NULL)
return;
mtx_unlock(m);
}
/* Section 5.2.9.1: global lock acquire/release functions */
#define GL_ACQUIRED (-1)
#define GL_BUSY 0
#define GL_BIT_PENDING 0x1
#define GL_BIT_OWNED 0x2
#define GL_BIT_MASK (GL_BIT_PENDING | GL_BIT_OWNED)
/*
* Acquire the global lock. If busy, set the pending bit. The caller
* will wait for notification from the BIOS that the lock is available
* and then attempt to acquire it again.
*/
int
acpi_acquire_global_lock(uint32_t *lock)
{
uint32_t new, old;
do {
old = *lock;
new = ((old & ~GL_BIT_MASK) | GL_BIT_OWNED) |
((old >> 1) & GL_BIT_PENDING);
} while (atomic_cmpset_acq_int(lock, old, new) == 0);
return ((new < GL_BIT_MASK) ? GL_ACQUIRED : GL_BUSY);
}
/*
* Release the global lock, returning whether there is a waiter pending.
* If the BIOS set the pending bit, OSPM must notify the BIOS when it
* releases the lock.
*/
int
acpi_release_global_lock(uint32_t *lock)
{
uint32_t new, old;
do {
old = *lock;
new = old & ~GL_BIT_MASK;
} while (atomic_cmpset_rel_int(lock, old, new) == 0);
return (old & GL_BIT_PENDING);
}
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