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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2005 Intel Corporation
4 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
5 *
6 * Alex Chiang <achiang@hp.com>
7 * - Unified x86/ia64 implementations
8 *
9 * I/O APIC hotplug support
10 * Yinghai Lu <yinghai@kernel.org>
11 * Jiang Liu <jiang.liu@intel.com>
12 */
13#include <linux/export.h>
14#include <linux/acpi.h>
15#include <acpi/processor.h>
16
17#define _COMPONENT ACPI_PROCESSOR_COMPONENT
18ACPI_MODULE_NAME("processor_core");
19
20static struct acpi_table_madt *get_madt_table(void)
21{
22 static struct acpi_table_madt *madt;
23 static int read_madt;
24
25 if (!read_madt) {
26 if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0,
27 (struct acpi_table_header **)&madt)))
28 madt = NULL;
29 read_madt++;
30 }
31
32 return madt;
33}
34
35static int map_lapic_id(struct acpi_subtable_header *entry,
36 u32 acpi_id, phys_cpuid_t *apic_id)
37{
38 struct acpi_madt_local_apic *lapic =
39 container_of(entry, struct acpi_madt_local_apic, header);
40
41 if (!(lapic->lapic_flags & ACPI_MADT_ENABLED))
42 return -ENODEV;
43
44 if (lapic->processor_id != acpi_id)
45 return -EINVAL;
46
47 *apic_id = lapic->id;
48 return 0;
49}
50
51static int map_x2apic_id(struct acpi_subtable_header *entry,
52 int device_declaration, u32 acpi_id, phys_cpuid_t *apic_id)
53{
54 struct acpi_madt_local_x2apic *apic =
55 container_of(entry, struct acpi_madt_local_x2apic, header);
56
57 if (!(apic->lapic_flags & ACPI_MADT_ENABLED))
58 return -ENODEV;
59
60 if (device_declaration && (apic->uid == acpi_id)) {
61 *apic_id = apic->local_apic_id;
62 return 0;
63 }
64
65 return -EINVAL;
66}
67
68static int map_lsapic_id(struct acpi_subtable_header *entry,
69 int device_declaration, u32 acpi_id, phys_cpuid_t *apic_id)
70{
71 struct acpi_madt_local_sapic *lsapic =
72 container_of(entry, struct acpi_madt_local_sapic, header);
73
74 if (!(lsapic->lapic_flags & ACPI_MADT_ENABLED))
75 return -ENODEV;
76
77 if (device_declaration) {
78 if ((entry->length < 16) || (lsapic->uid != acpi_id))
79 return -EINVAL;
80 } else if (lsapic->processor_id != acpi_id)
81 return -EINVAL;
82
83 *apic_id = (lsapic->id << 8) | lsapic->eid;
84 return 0;
85}
86
87/*
88 * Retrieve the ARM CPU physical identifier (MPIDR)
89 */
90static int map_gicc_mpidr(struct acpi_subtable_header *entry,
91 int device_declaration, u32 acpi_id, phys_cpuid_t *mpidr)
92{
93 struct acpi_madt_generic_interrupt *gicc =
94 container_of(entry, struct acpi_madt_generic_interrupt, header);
95
96 if (!(gicc->flags & ACPI_MADT_ENABLED))
97 return -ENODEV;
98
99 /* device_declaration means Device object in DSDT, in the
100 * GIC interrupt model, logical processors are required to
101 * have a Processor Device object in the DSDT, so we should
102 * check device_declaration here
103 */
104 if (device_declaration && (gicc->uid == acpi_id)) {
105 *mpidr = gicc->arm_mpidr;
106 return 0;
107 }
108
109 return -EINVAL;
110}
111
112static phys_cpuid_t map_madt_entry(struct acpi_table_madt *madt,
113 int type, u32 acpi_id)
114{
115 unsigned long madt_end, entry;
116 phys_cpuid_t phys_id = PHYS_CPUID_INVALID; /* CPU hardware ID */
117
118 if (!madt)
119 return phys_id;
120
121 entry = (unsigned long)madt;
122 madt_end = entry + madt->header.length;
123
124 /* Parse all entries looking for a match. */
125
126 entry += sizeof(struct acpi_table_madt);
127 while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
128 struct acpi_subtable_header *header =
129 (struct acpi_subtable_header *)entry;
130 if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
131 if (!map_lapic_id(header, acpi_id, &phys_id))
132 break;
133 } else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC) {
134 if (!map_x2apic_id(header, type, acpi_id, &phys_id))
135 break;
136 } else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
137 if (!map_lsapic_id(header, type, acpi_id, &phys_id))
138 break;
139 } else if (header->type == ACPI_MADT_TYPE_GENERIC_INTERRUPT) {
140 if (!map_gicc_mpidr(header, type, acpi_id, &phys_id))
141 break;
142 }
143 entry += header->length;
144 }
145 return phys_id;
146}
147
148phys_cpuid_t __init acpi_map_madt_entry(u32 acpi_id)
149{
150 struct acpi_table_madt *madt = NULL;
151 phys_cpuid_t rv;
152
153 acpi_get_table(ACPI_SIG_MADT, 0,
154 (struct acpi_table_header **)&madt);
155 if (!madt)
156 return PHYS_CPUID_INVALID;
157
158 rv = map_madt_entry(madt, 1, acpi_id);
159
160 acpi_put_table((struct acpi_table_header *)madt);
161
162 return rv;
163}
164
165static phys_cpuid_t map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
166{
167 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
168 union acpi_object *obj;
169 struct acpi_subtable_header *header;
170 phys_cpuid_t phys_id = PHYS_CPUID_INVALID;
171
172 if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
173 goto exit;
174
175 if (!buffer.length || !buffer.pointer)
176 goto exit;
177
178 obj = buffer.pointer;
179 if (obj->type != ACPI_TYPE_BUFFER ||
180 obj->buffer.length < sizeof(struct acpi_subtable_header)) {
181 goto exit;
182 }
183
184 header = (struct acpi_subtable_header *)obj->buffer.pointer;
185 if (header->type == ACPI_MADT_TYPE_LOCAL_APIC)
186 map_lapic_id(header, acpi_id, &phys_id);
187 else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC)
188 map_lsapic_id(header, type, acpi_id, &phys_id);
189 else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC)
190 map_x2apic_id(header, type, acpi_id, &phys_id);
191 else if (header->type == ACPI_MADT_TYPE_GENERIC_INTERRUPT)
192 map_gicc_mpidr(header, type, acpi_id, &phys_id);
193
194exit:
195 kfree(buffer.pointer);
196 return phys_id;
197}
198
199phys_cpuid_t acpi_get_phys_id(acpi_handle handle, int type, u32 acpi_id)
200{
201 phys_cpuid_t phys_id;
202
203 phys_id = map_mat_entry(handle, type, acpi_id);
204 if (invalid_phys_cpuid(phys_id))
205 phys_id = map_madt_entry(get_madt_table(), type, acpi_id);
206
207 return phys_id;
208}
209EXPORT_SYMBOL_GPL(acpi_get_phys_id);
210
211int acpi_map_cpuid(phys_cpuid_t phys_id, u32 acpi_id)
212{
213#ifdef CONFIG_SMP
214 int i;
215#endif
216
217 if (invalid_phys_cpuid(phys_id)) {
218 /*
219 * On UP processor, there is no _MAT or MADT table.
220 * So above phys_id is always set to PHYS_CPUID_INVALID.
221 *
222 * BIOS may define multiple CPU handles even for UP processor.
223 * For example,
224 *
225 * Scope (_PR)
226 * {
227 * Processor (CPU0, 0x00, 0x00000410, 0x06) {}
228 * Processor (CPU1, 0x01, 0x00000410, 0x06) {}
229 * Processor (CPU2, 0x02, 0x00000410, 0x06) {}
230 * Processor (CPU3, 0x03, 0x00000410, 0x06) {}
231 * }
232 *
233 * Ignores phys_id and always returns 0 for the processor
234 * handle with acpi id 0 if nr_cpu_ids is 1.
235 * This should be the case if SMP tables are not found.
236 * Return -EINVAL for other CPU's handle.
237 */
238 if (nr_cpu_ids <= 1 && acpi_id == 0)
239 return acpi_id;
240 else
241 return -EINVAL;
242 }
243
244#ifdef CONFIG_SMP
245 for_each_possible_cpu(i) {
246 if (cpu_physical_id(i) == phys_id)
247 return i;
248 }
249#else
250 /* In UP kernel, only processor 0 is valid */
251 if (phys_id == 0)
252 return phys_id;
253#endif
254 return -ENODEV;
255}
256
257int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
258{
259 phys_cpuid_t phys_id;
260
261 phys_id = acpi_get_phys_id(handle, type, acpi_id);
262
263 return acpi_map_cpuid(phys_id, acpi_id);
264}
265EXPORT_SYMBOL_GPL(acpi_get_cpuid);
266
267#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
268static int get_ioapic_id(struct acpi_subtable_header *entry, u32 gsi_base,
269 u64 *phys_addr, int *ioapic_id)
270{
271 struct acpi_madt_io_apic *ioapic = (struct acpi_madt_io_apic *)entry;
272
273 if (ioapic->global_irq_base != gsi_base)
274 return 0;
275
276 *phys_addr = ioapic->address;
277 *ioapic_id = ioapic->id;
278 return 1;
279}
280
281static int parse_madt_ioapic_entry(u32 gsi_base, u64 *phys_addr)
282{
283 struct acpi_subtable_header *hdr;
284 unsigned long madt_end, entry;
285 struct acpi_table_madt *madt;
286 int apic_id = -1;
287
288 madt = get_madt_table();
289 if (!madt)
290 return apic_id;
291
292 entry = (unsigned long)madt;
293 madt_end = entry + madt->header.length;
294
295 /* Parse all entries looking for a match. */
296 entry += sizeof(struct acpi_table_madt);
297 while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
298 hdr = (struct acpi_subtable_header *)entry;
299 if (hdr->type == ACPI_MADT_TYPE_IO_APIC &&
300 get_ioapic_id(hdr, gsi_base, phys_addr, &apic_id))
301 break;
302 else
303 entry += hdr->length;
304 }
305
306 return apic_id;
307}
308
309static int parse_mat_ioapic_entry(acpi_handle handle, u32 gsi_base,
310 u64 *phys_addr)
311{
312 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
313 struct acpi_subtable_header *header;
314 union acpi_object *obj;
315 int apic_id = -1;
316
317 if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
318 goto exit;
319
320 if (!buffer.length || !buffer.pointer)
321 goto exit;
322
323 obj = buffer.pointer;
324 if (obj->type != ACPI_TYPE_BUFFER ||
325 obj->buffer.length < sizeof(struct acpi_subtable_header))
326 goto exit;
327
328 header = (struct acpi_subtable_header *)obj->buffer.pointer;
329 if (header->type == ACPI_MADT_TYPE_IO_APIC)
330 get_ioapic_id(header, gsi_base, phys_addr, &apic_id);
331
332exit:
333 kfree(buffer.pointer);
334 return apic_id;
335}
336
337/**
338 * acpi_get_ioapic_id - Get IOAPIC ID and physical address matching @gsi_base
339 * @handle: ACPI object for IOAPIC device
340 * @gsi_base: GSI base to match with
341 * @phys_addr: Pointer to store physical address of matching IOAPIC record
342 *
343 * Walk resources returned by ACPI_MAT method, then ACPI MADT table, to search
344 * for an ACPI IOAPIC record matching @gsi_base.
345 * Return IOAPIC id and store physical address in @phys_addr if found a match,
346 * otherwise return <0.
347 */
348int acpi_get_ioapic_id(acpi_handle handle, u32 gsi_base, u64 *phys_addr)
349{
350 int apic_id;
351
352 apic_id = parse_mat_ioapic_entry(handle, gsi_base, phys_addr);
353 if (apic_id == -1)
354 apic_id = parse_madt_ioapic_entry(gsi_base, phys_addr);
355
356 return apic_id;
357}
358#endif /* CONFIG_ACPI_HOTPLUG_IOAPIC */
1/*
2 * Copyright (C) 2005 Intel Corporation
3 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
4 *
5 * Alex Chiang <achiang@hp.com>
6 * - Unified x86/ia64 implementations
7 *
8 * I/O APIC hotplug support
9 * Yinghai Lu <yinghai@kernel.org>
10 * Jiang Liu <jiang.liu@intel.com>
11 */
12#include <linux/export.h>
13#include <linux/acpi.h>
14#include <acpi/processor.h>
15
16#define _COMPONENT ACPI_PROCESSOR_COMPONENT
17ACPI_MODULE_NAME("processor_core");
18
19static struct acpi_table_madt *get_madt_table(void)
20{
21 static struct acpi_table_madt *madt;
22 static int read_madt;
23
24 if (!read_madt) {
25 if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0,
26 (struct acpi_table_header **)&madt)))
27 madt = NULL;
28 read_madt++;
29 }
30
31 return madt;
32}
33
34static int map_lapic_id(struct acpi_subtable_header *entry,
35 u32 acpi_id, phys_cpuid_t *apic_id)
36{
37 struct acpi_madt_local_apic *lapic =
38 container_of(entry, struct acpi_madt_local_apic, header);
39
40 if (!(lapic->lapic_flags & ACPI_MADT_ENABLED))
41 return -ENODEV;
42
43 if (lapic->processor_id != acpi_id)
44 return -EINVAL;
45
46 *apic_id = lapic->id;
47 return 0;
48}
49
50static int map_x2apic_id(struct acpi_subtable_header *entry,
51 int device_declaration, u32 acpi_id, phys_cpuid_t *apic_id)
52{
53 struct acpi_madt_local_x2apic *apic =
54 container_of(entry, struct acpi_madt_local_x2apic, header);
55
56 if (!(apic->lapic_flags & ACPI_MADT_ENABLED))
57 return -ENODEV;
58
59 if (device_declaration && (apic->uid == acpi_id)) {
60 *apic_id = apic->local_apic_id;
61 return 0;
62 }
63
64 return -EINVAL;
65}
66
67static int map_lsapic_id(struct acpi_subtable_header *entry,
68 int device_declaration, u32 acpi_id, phys_cpuid_t *apic_id)
69{
70 struct acpi_madt_local_sapic *lsapic =
71 container_of(entry, struct acpi_madt_local_sapic, header);
72
73 if (!(lsapic->lapic_flags & ACPI_MADT_ENABLED))
74 return -ENODEV;
75
76 if (device_declaration) {
77 if ((entry->length < 16) || (lsapic->uid != acpi_id))
78 return -EINVAL;
79 } else if (lsapic->processor_id != acpi_id)
80 return -EINVAL;
81
82 *apic_id = (lsapic->id << 8) | lsapic->eid;
83 return 0;
84}
85
86/*
87 * Retrieve the ARM CPU physical identifier (MPIDR)
88 */
89static int map_gicc_mpidr(struct acpi_subtable_header *entry,
90 int device_declaration, u32 acpi_id, phys_cpuid_t *mpidr)
91{
92 struct acpi_madt_generic_interrupt *gicc =
93 container_of(entry, struct acpi_madt_generic_interrupt, header);
94
95 if (!(gicc->flags & ACPI_MADT_ENABLED))
96 return -ENODEV;
97
98 /* device_declaration means Device object in DSDT, in the
99 * GIC interrupt model, logical processors are required to
100 * have a Processor Device object in the DSDT, so we should
101 * check device_declaration here
102 */
103 if (device_declaration && (gicc->uid == acpi_id)) {
104 *mpidr = gicc->arm_mpidr;
105 return 0;
106 }
107
108 return -EINVAL;
109}
110
111static phys_cpuid_t map_madt_entry(struct acpi_table_madt *madt,
112 int type, u32 acpi_id)
113{
114 unsigned long madt_end, entry;
115 phys_cpuid_t phys_id = PHYS_CPUID_INVALID; /* CPU hardware ID */
116
117 if (!madt)
118 return phys_id;
119
120 entry = (unsigned long)madt;
121 madt_end = entry + madt->header.length;
122
123 /* Parse all entries looking for a match. */
124
125 entry += sizeof(struct acpi_table_madt);
126 while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
127 struct acpi_subtable_header *header =
128 (struct acpi_subtable_header *)entry;
129 if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
130 if (!map_lapic_id(header, acpi_id, &phys_id))
131 break;
132 } else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC) {
133 if (!map_x2apic_id(header, type, acpi_id, &phys_id))
134 break;
135 } else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
136 if (!map_lsapic_id(header, type, acpi_id, &phys_id))
137 break;
138 } else if (header->type == ACPI_MADT_TYPE_GENERIC_INTERRUPT) {
139 if (!map_gicc_mpidr(header, type, acpi_id, &phys_id))
140 break;
141 }
142 entry += header->length;
143 }
144 return phys_id;
145}
146
147phys_cpuid_t __init acpi_map_madt_entry(u32 acpi_id)
148{
149 struct acpi_table_madt *madt = NULL;
150 phys_cpuid_t rv;
151
152 acpi_get_table(ACPI_SIG_MADT, 0,
153 (struct acpi_table_header **)&madt);
154 if (!madt)
155 return PHYS_CPUID_INVALID;
156
157 rv = map_madt_entry(madt, 1, acpi_id);
158
159 acpi_put_table((struct acpi_table_header *)madt);
160
161 return rv;
162}
163
164static phys_cpuid_t map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
165{
166 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
167 union acpi_object *obj;
168 struct acpi_subtable_header *header;
169 phys_cpuid_t phys_id = PHYS_CPUID_INVALID;
170
171 if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
172 goto exit;
173
174 if (!buffer.length || !buffer.pointer)
175 goto exit;
176
177 obj = buffer.pointer;
178 if (obj->type != ACPI_TYPE_BUFFER ||
179 obj->buffer.length < sizeof(struct acpi_subtable_header)) {
180 goto exit;
181 }
182
183 header = (struct acpi_subtable_header *)obj->buffer.pointer;
184 if (header->type == ACPI_MADT_TYPE_LOCAL_APIC)
185 map_lapic_id(header, acpi_id, &phys_id);
186 else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC)
187 map_lsapic_id(header, type, acpi_id, &phys_id);
188 else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC)
189 map_x2apic_id(header, type, acpi_id, &phys_id);
190 else if (header->type == ACPI_MADT_TYPE_GENERIC_INTERRUPT)
191 map_gicc_mpidr(header, type, acpi_id, &phys_id);
192
193exit:
194 kfree(buffer.pointer);
195 return phys_id;
196}
197
198phys_cpuid_t acpi_get_phys_id(acpi_handle handle, int type, u32 acpi_id)
199{
200 phys_cpuid_t phys_id;
201
202 phys_id = map_mat_entry(handle, type, acpi_id);
203 if (invalid_phys_cpuid(phys_id))
204 phys_id = map_madt_entry(get_madt_table(), type, acpi_id);
205
206 return phys_id;
207}
208
209int acpi_map_cpuid(phys_cpuid_t phys_id, u32 acpi_id)
210{
211#ifdef CONFIG_SMP
212 int i;
213#endif
214
215 if (invalid_phys_cpuid(phys_id)) {
216 /*
217 * On UP processor, there is no _MAT or MADT table.
218 * So above phys_id is always set to PHYS_CPUID_INVALID.
219 *
220 * BIOS may define multiple CPU handles even for UP processor.
221 * For example,
222 *
223 * Scope (_PR)
224 * {
225 * Processor (CPU0, 0x00, 0x00000410, 0x06) {}
226 * Processor (CPU1, 0x01, 0x00000410, 0x06) {}
227 * Processor (CPU2, 0x02, 0x00000410, 0x06) {}
228 * Processor (CPU3, 0x03, 0x00000410, 0x06) {}
229 * }
230 *
231 * Ignores phys_id and always returns 0 for the processor
232 * handle with acpi id 0 if nr_cpu_ids is 1.
233 * This should be the case if SMP tables are not found.
234 * Return -EINVAL for other CPU's handle.
235 */
236 if (nr_cpu_ids <= 1 && acpi_id == 0)
237 return acpi_id;
238 else
239 return -EINVAL;
240 }
241
242#ifdef CONFIG_SMP
243 for_each_possible_cpu(i) {
244 if (cpu_physical_id(i) == phys_id)
245 return i;
246 }
247#else
248 /* In UP kernel, only processor 0 is valid */
249 if (phys_id == 0)
250 return phys_id;
251#endif
252 return -ENODEV;
253}
254
255int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
256{
257 phys_cpuid_t phys_id;
258
259 phys_id = acpi_get_phys_id(handle, type, acpi_id);
260
261 return acpi_map_cpuid(phys_id, acpi_id);
262}
263EXPORT_SYMBOL_GPL(acpi_get_cpuid);
264
265#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
266static int get_ioapic_id(struct acpi_subtable_header *entry, u32 gsi_base,
267 u64 *phys_addr, int *ioapic_id)
268{
269 struct acpi_madt_io_apic *ioapic = (struct acpi_madt_io_apic *)entry;
270
271 if (ioapic->global_irq_base != gsi_base)
272 return 0;
273
274 *phys_addr = ioapic->address;
275 *ioapic_id = ioapic->id;
276 return 1;
277}
278
279static int parse_madt_ioapic_entry(u32 gsi_base, u64 *phys_addr)
280{
281 struct acpi_subtable_header *hdr;
282 unsigned long madt_end, entry;
283 struct acpi_table_madt *madt;
284 int apic_id = -1;
285
286 madt = get_madt_table();
287 if (!madt)
288 return apic_id;
289
290 entry = (unsigned long)madt;
291 madt_end = entry + madt->header.length;
292
293 /* Parse all entries looking for a match. */
294 entry += sizeof(struct acpi_table_madt);
295 while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
296 hdr = (struct acpi_subtable_header *)entry;
297 if (hdr->type == ACPI_MADT_TYPE_IO_APIC &&
298 get_ioapic_id(hdr, gsi_base, phys_addr, &apic_id))
299 break;
300 else
301 entry += hdr->length;
302 }
303
304 return apic_id;
305}
306
307static int parse_mat_ioapic_entry(acpi_handle handle, u32 gsi_base,
308 u64 *phys_addr)
309{
310 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
311 struct acpi_subtable_header *header;
312 union acpi_object *obj;
313 int apic_id = -1;
314
315 if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
316 goto exit;
317
318 if (!buffer.length || !buffer.pointer)
319 goto exit;
320
321 obj = buffer.pointer;
322 if (obj->type != ACPI_TYPE_BUFFER ||
323 obj->buffer.length < sizeof(struct acpi_subtable_header))
324 goto exit;
325
326 header = (struct acpi_subtable_header *)obj->buffer.pointer;
327 if (header->type == ACPI_MADT_TYPE_IO_APIC)
328 get_ioapic_id(header, gsi_base, phys_addr, &apic_id);
329
330exit:
331 kfree(buffer.pointer);
332 return apic_id;
333}
334
335/**
336 * acpi_get_ioapic_id - Get IOAPIC ID and physical address matching @gsi_base
337 * @handle: ACPI object for IOAPIC device
338 * @gsi_base: GSI base to match with
339 * @phys_addr: Pointer to store physical address of matching IOAPIC record
340 *
341 * Walk resources returned by ACPI_MAT method, then ACPI MADT table, to search
342 * for an ACPI IOAPIC record matching @gsi_base.
343 * Return IOAPIC id and store physical address in @phys_addr if found a match,
344 * otherwise return <0.
345 */
346int acpi_get_ioapic_id(acpi_handle handle, u32 gsi_base, u64 *phys_addr)
347{
348 int apic_id;
349
350 apic_id = parse_mat_ioapic_entry(handle, gsi_base, phys_addr);
351 if (apic_id == -1)
352 apic_id = parse_madt_ioapic_entry(gsi_base, phys_addr);
353
354 return apic_id;
355}
356#endif /* CONFIG_ACPI_HOTPLUG_IOAPIC */