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