summaryrefslogtreecommitdiffstats
path: root/drivers/acpi/acpica/utownerid.c
blob: 2959217067cb012beaa8f6de84df8299c094d3fe (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
/*******************************************************************************
 *
 * Module Name: utownerid - Support for Table/Method Owner IDs
 *
 ******************************************************************************/

/*
 * Copyright (C) 2000 - 2015, Intel Corp.
 * 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,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR 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 DAMAGES.
 */

#include <acpi/acpi.h>
#include "accommon.h"
#include "acnamesp.h"

#define _COMPONENT          ACPI_UTILITIES
ACPI_MODULE_NAME("utownerid")

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_allocate_owner_id
 *
 * PARAMETERS:  owner_id        - Where the new owner ID is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Allocate a table or method owner ID. The owner ID is used to
 *              track objects created by the table or method, to be deleted
 *              when the method exits or the table is unloaded.
 *
 ******************************************************************************/
acpi_status acpi_ut_allocate_owner_id(acpi_owner_id * owner_id)
{
	u32 i;
	u32 j;
	u32 k;
	acpi_status status;

	ACPI_FUNCTION_TRACE(ut_allocate_owner_id);

	/* Guard against multiple allocations of ID to the same location */

	if (*owner_id) {
		ACPI_ERROR((AE_INFO, "Owner ID [0x%2.2X] already exists",
			    *owner_id));
		return_ACPI_STATUS(AE_ALREADY_EXISTS);
	}

	/* Mutex for the global ID mask */

	status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES);
	if (ACPI_FAILURE(status)) {
		return_ACPI_STATUS(status);
	}

	/*
	 * Find a free owner ID, cycle through all possible IDs on repeated
	 * allocations. (ACPI_NUM_OWNERID_MASKS + 1) because first index may have
	 * to be scanned twice.
	 */
	for (i = 0, j = acpi_gbl_last_owner_id_index;
	     i < (ACPI_NUM_OWNERID_MASKS + 1); i++, j++) {
		if (j >= ACPI_NUM_OWNERID_MASKS) {
			j = 0;	/* Wraparound to start of mask array */
		}

		for (k = acpi_gbl_next_owner_id_offset; k < 32; k++) {
			if (acpi_gbl_owner_id_mask[j] == ACPI_UINT32_MAX) {

				/* There are no free IDs in this mask */

				break;
			}

			if (!(acpi_gbl_owner_id_mask[j] & (1 << k))) {
				/*
				 * Found a free ID. The actual ID is the bit index plus one,
				 * making zero an invalid Owner ID. Save this as the last ID
				 * allocated and update the global ID mask.
				 */
				acpi_gbl_owner_id_mask[j] |= (1 << k);

				acpi_gbl_last_owner_id_index = (u8)j;
				acpi_gbl_next_owner_id_offset = (u8)(k + 1);

				/*
				 * Construct encoded ID from the index and bit position
				 *
				 * Note: Last [j].k (bit 255) is never used and is marked
				 * permanently allocated (prevents +1 overflow)
				 */
				*owner_id =
				    (acpi_owner_id) ((k + 1) + ACPI_MUL_32(j));

				ACPI_DEBUG_PRINT((ACPI_DB_VALUES,
						  "Allocated OwnerId: %2.2X\n",
						  (unsigned int)*owner_id));
				goto exit;
			}
		}

		acpi_gbl_next_owner_id_offset = 0;
	}

	/*
	 * All owner_ids have been allocated. This typically should
	 * not happen since the IDs are reused after deallocation. The IDs are
	 * allocated upon table load (one per table) and method execution, and
	 * they are released when a table is unloaded or a method completes
	 * execution.
	 *
	 * If this error happens, there may be very deep nesting of invoked control
	 * methods, or there may be a bug where the IDs are not released.
	 */
	status = AE_OWNER_ID_LIMIT;
	ACPI_ERROR((AE_INFO,
		    "Could not allocate new OwnerId (255 max), AE_OWNER_ID_LIMIT"));

exit:
	(void)acpi_ut_release_mutex(ACPI_MTX_CACHES);
	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_release_owner_id
 *
 * PARAMETERS:  owner_id_ptr        - Pointer to a previously allocated owner_ID
 *
 * RETURN:      None. No error is returned because we are either exiting a
 *              control method or unloading a table. Either way, we would
 *              ignore any error anyway.
 *
 * DESCRIPTION: Release a table or method owner ID. Valid IDs are 1 - 255
 *
 ******************************************************************************/

void acpi_ut_release_owner_id(acpi_owner_id * owner_id_ptr)
{
	acpi_owner_id owner_id = *owner_id_ptr;
	acpi_status status;
	u32 index;
	u32 bit;

	ACPI_FUNCTION_TRACE_U32(ut_release_owner_id, owner_id);

	/* Always clear the input owner_id (zero is an invalid ID) */

	*owner_id_ptr = 0;

	/* Zero is not a valid owner_ID */

	if (owner_id == 0) {
		ACPI_ERROR((AE_INFO, "Invalid OwnerId: 0x%2.2X", owner_id));
		return_VOID;
	}

	/* Mutex for the global ID mask */

	status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES);
	if (ACPI_FAILURE(status)) {
		return_VOID;
	}

	/* Normalize the ID to zero */

	owner_id--;

	/* Decode ID to index/offset pair */

	index = ACPI_DIV_32(owner_id);
	bit = 1 << ACPI_MOD_32(owner_id);

	/* Free the owner ID only if it is valid */

	if (acpi_gbl_owner_id_mask[index] & bit) {
		acpi_gbl_owner_id_mask[index] ^= bit;
	} else {
		ACPI_ERROR((AE_INFO,
			    "Release of non-allocated OwnerId: 0x%2.2X",
			    owner_id + 1));
	}

	(void)acpi_ut_release_mutex(ACPI_MTX_CACHES);
	return_VOID;
}