1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 2 /******************************************************************************* 3 * 4 * Module Name: utxfmutex - external AML mutex access functions 5 * 6 ******************************************************************************/ 7 8 #include <acpi/acpi.h> 9 #include "accommon.h" 10 #include "acnamesp.h" 11 12 #define _COMPONENT ACPI_UTILITIES 13 ACPI_MODULE_NAME("utxfmutex") 14 15 /* Local prototypes */ 16 static acpi_status 17 acpi_ut_get_mutex_object(acpi_handle handle, 18 acpi_string pathname, 19 union acpi_operand_object **ret_obj); 20 21 /******************************************************************************* 22 * 23 * FUNCTION: acpi_ut_get_mutex_object 24 * 25 * PARAMETERS: handle - Mutex or prefix handle (optional) 26 * pathname - Mutex pathname (optional) 27 * ret_obj - Where the mutex object is returned 28 * 29 * RETURN: Status 30 * 31 * DESCRIPTION: Get an AML mutex object. The mutex node is pointed to by 32 * Handle:Pathname. Either Handle or Pathname can be NULL, but 33 * not both. 34 * 35 ******************************************************************************/ 36 37 static acpi_status 38 acpi_ut_get_mutex_object(acpi_handle handle, 39 acpi_string pathname, 40 union acpi_operand_object **ret_obj) 41 { 42 struct acpi_namespace_node *mutex_node; 43 union acpi_operand_object *mutex_obj; 44 acpi_status status; 45 46 /* Parameter validation */ 47 48 if (!ret_obj || (!handle && !pathname)) { 49 return (AE_BAD_PARAMETER); 50 } 51 52 /* Get a the namespace node for the mutex */ 53 54 mutex_node = handle; 55 if (pathname != NULL) { 56 status = 57 acpi_get_handle(handle, pathname, 58 ACPI_CAST_PTR(acpi_handle, &mutex_node)); 59 if (ACPI_FAILURE(status)) { 60 return (status); 61 } 62 } 63 64 /* Ensure that we actually have a Mutex object */ 65 66 if (!mutex_node || (mutex_node->type != ACPI_TYPE_MUTEX)) { 67 return (AE_TYPE); 68 } 69 70 /* Get the low-level mutex object */ 71 72 mutex_obj = acpi_ns_get_attached_object(mutex_node); 73 if (!mutex_obj) { 74 return (AE_NULL_OBJECT); 75 } 76 77 *ret_obj = mutex_obj; 78 return (AE_OK); 79 } 80 81 /******************************************************************************* 82 * 83 * FUNCTION: acpi_acquire_mutex 84 * 85 * PARAMETERS: handle - Mutex or prefix handle (optional) 86 * pathname - Mutex pathname (optional) 87 * timeout - Max time to wait for the lock (millisec) 88 * 89 * RETURN: Status 90 * 91 * DESCRIPTION: Acquire an AML mutex. This is a device driver interface to 92 * AML mutex objects, and allows for transaction locking between 93 * drivers and AML code. The mutex node is pointed to by 94 * Handle:Pathname. Either Handle or Pathname can be NULL, but 95 * not both. 96 * 97 ******************************************************************************/ 98 99 acpi_status 100 acpi_acquire_mutex(acpi_handle handle, acpi_string pathname, u16 timeout) 101 { 102 acpi_status status; 103 union acpi_operand_object *mutex_obj; 104 105 /* Get the low-level mutex associated with Handle:Pathname */ 106 107 status = acpi_ut_get_mutex_object(handle, pathname, &mutex_obj); 108 if (ACPI_FAILURE(status)) { 109 return (status); 110 } 111 112 /* Acquire the OS mutex */ 113 114 status = acpi_os_acquire_mutex(mutex_obj->mutex.os_mutex, timeout); 115 return (status); 116 } 117 118 ACPI_EXPORT_SYMBOL(acpi_acquire_mutex) 119 120 /******************************************************************************* 121 * 122 * FUNCTION: acpi_release_mutex 123 * 124 * PARAMETERS: handle - Mutex or prefix handle (optional) 125 * pathname - Mutex pathname (optional) 126 * 127 * RETURN: Status 128 * 129 * DESCRIPTION: Release an AML mutex. This is a device driver interface to 130 * AML mutex objects, and allows for transaction locking between 131 * drivers and AML code. The mutex node is pointed to by 132 * Handle:Pathname. Either Handle or Pathname can be NULL, but 133 * not both. 134 * 135 ******************************************************************************/ 136 acpi_status acpi_release_mutex(acpi_handle handle, acpi_string pathname) 137 { 138 acpi_status status; 139 union acpi_operand_object *mutex_obj; 140 141 /* Get the low-level mutex associated with Handle:Pathname */ 142 143 status = acpi_ut_get_mutex_object(handle, pathname, &mutex_obj); 144 if (ACPI_FAILURE(status)) { 145 return (status); 146 } 147 148 /* Release the OS mutex */ 149 150 acpi_os_release_mutex(mutex_obj->mutex.os_mutex); 151 return (AE_OK); 152 } 153 154 ACPI_EXPORT_SYMBOL(acpi_release_mutex) 155