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Diffstat (limited to 'drivers/acpi/acpica/utxfmutex.c')
| -rw-r--r-- | drivers/acpi/acpica/utxfmutex.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/drivers/acpi/acpica/utxfmutex.c b/drivers/acpi/acpica/utxfmutex.c new file mode 100644 index 000000000..be24db254 --- /dev/null +++ b/drivers/acpi/acpica/utxfmutex.c @@ -0,0 +1,154 @@ +// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 +/******************************************************************************* + * + * Module Name: utxfmutex - external AML mutex access functions + * + ******************************************************************************/ + +#include <acpi/acpi.h> +#include "accommon.h" +#include "acnamesp.h" + +#define _COMPONENT ACPI_UTILITIES +ACPI_MODULE_NAME("utxfmutex") + +/* Local prototypes */ +static acpi_status +acpi_ut_get_mutex_object(acpi_handle handle, + acpi_string pathname, + union acpi_operand_object **ret_obj); + +/******************************************************************************* + * + * FUNCTION: acpi_ut_get_mutex_object + * + * PARAMETERS: handle - Mutex or prefix handle (optional) + * pathname - Mutex pathname (optional) + * ret_obj - Where the mutex object is returned + * + * RETURN: Status + * + * DESCRIPTION: Get an AML mutex object. The mutex node is pointed to by + * Handle:Pathname. Either Handle or Pathname can be NULL, but + * not both. + * + ******************************************************************************/ + +static acpi_status +acpi_ut_get_mutex_object(acpi_handle handle, + acpi_string pathname, + union acpi_operand_object **ret_obj) +{ + struct acpi_namespace_node *mutex_node; + union acpi_operand_object *mutex_obj; + acpi_status status; + + /* Parameter validation */ + + if (!ret_obj || (!handle && !pathname)) { + return (AE_BAD_PARAMETER); + } + + /* Get a the namespace node for the mutex */ + + mutex_node = handle; + if (pathname != NULL) { + status = + acpi_get_handle(handle, pathname, + ACPI_CAST_PTR(acpi_handle, &mutex_node)); + if (ACPI_FAILURE(status)) { + return (status); + } + } + + /* Ensure that we actually have a Mutex object */ + + if (!mutex_node || (mutex_node->type != ACPI_TYPE_MUTEX)) { + return (AE_TYPE); + } + + /* Get the low-level mutex object */ + + mutex_obj = acpi_ns_get_attached_object(mutex_node); + if (!mutex_obj) { + return (AE_NULL_OBJECT); + } + + *ret_obj = mutex_obj; + return (AE_OK); +} + +/******************************************************************************* + * + * FUNCTION: acpi_acquire_mutex + * + * PARAMETERS: handle - Mutex or prefix handle (optional) + * pathname - Mutex pathname (optional) + * timeout - Max time to wait for the lock (millisec) + * + * RETURN: Status + * + * DESCRIPTION: Acquire an AML mutex. This is a device driver interface to + * AML mutex objects, and allows for transaction locking between + * drivers and AML code. The mutex node is pointed to by + * Handle:Pathname. Either Handle or Pathname can be NULL, but + * not both. + * + ******************************************************************************/ + +acpi_status +acpi_acquire_mutex(acpi_handle handle, acpi_string pathname, u16 timeout) +{ + acpi_status status; + union acpi_operand_object *mutex_obj; + + /* Get the low-level mutex associated with Handle:Pathname */ + + status = acpi_ut_get_mutex_object(handle, pathname, &mutex_obj); + if (ACPI_FAILURE(status)) { + return (status); + } + + /* Acquire the OS mutex */ + + status = acpi_os_acquire_mutex(mutex_obj->mutex.os_mutex, timeout); + return (status); +} + +ACPI_EXPORT_SYMBOL(acpi_acquire_mutex) + +/******************************************************************************* + * + * FUNCTION: acpi_release_mutex + * + * PARAMETERS: handle - Mutex or prefix handle (optional) + * pathname - Mutex pathname (optional) + * + * RETURN: Status + * + * DESCRIPTION: Release an AML mutex. This is a device driver interface to + * AML mutex objects, and allows for transaction locking between + * drivers and AML code. The mutex node is pointed to by + * Handle:Pathname. Either Handle or Pathname can be NULL, but + * not both. + * + ******************************************************************************/ +acpi_status acpi_release_mutex(acpi_handle handle, acpi_string pathname) +{ + acpi_status status; + union acpi_operand_object *mutex_obj; + + /* Get the low-level mutex associated with Handle:Pathname */ + + status = acpi_ut_get_mutex_object(handle, pathname, &mutex_obj); + if (ACPI_FAILURE(status)) { + return (status); + } + + /* Release the OS mutex */ + + acpi_os_release_mutex(mutex_obj->mutex.os_mutex); + return (AE_OK); +} + +ACPI_EXPORT_SYMBOL(acpi_release_mutex) |