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v3.1
 
  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 *	Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
  8 *	- Added _PDC for platforms with Intel CPUs
 
 
  9 */
 10#include <linux/dmi.h>
 11#include <linux/slab.h>
 12
 13#include <acpi/acpi_drivers.h>
 14#include <acpi/processor.h>
 15
 16#include "internal.h"
 17
 18#define PREFIX			"ACPI: "
 19#define _COMPONENT		ACPI_PROCESSOR_COMPONENT
 20ACPI_MODULE_NAME("processor_core");
 21
 22static int __init set_no_mwait(const struct dmi_system_id *id)
 23{
 24	printk(KERN_NOTICE PREFIX "%s detected - "
 25		"disabling mwait for CPU C-states\n", id->ident);
 26	boot_option_idle_override = IDLE_NOMWAIT;
 27	return 0;
 28}
 29
 30static struct dmi_system_id __initdata processor_idle_dmi_table[] = {
 31	{
 32	set_no_mwait, "Extensa 5220", {
 33	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
 34	DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
 35	DMI_MATCH(DMI_PRODUCT_VERSION, "0100"),
 36	DMI_MATCH(DMI_BOARD_NAME, "Columbia") }, NULL},
 37	{},
 38};
 39
 40static int map_lapic_id(struct acpi_subtable_header *entry,
 41		 u32 acpi_id, int *apic_id)
 42{
 43	struct acpi_madt_local_apic *lapic =
 44		(struct acpi_madt_local_apic *)entry;
 45
 46	if (!(lapic->lapic_flags & ACPI_MADT_ENABLED))
 47		return 0;
 48
 49	if (lapic->processor_id != acpi_id)
 50		return 0;
 51
 52	*apic_id = lapic->id;
 53	return 1;
 54}
 55
 56static int map_x2apic_id(struct acpi_subtable_header *entry,
 57			 int device_declaration, u32 acpi_id, int *apic_id)
 58{
 59	struct acpi_madt_local_x2apic *apic =
 60		(struct acpi_madt_local_x2apic *)entry;
 61
 62	if (!(apic->lapic_flags & ACPI_MADT_ENABLED))
 63		return 0;
 64
 65	if (device_declaration && (apic->uid == acpi_id)) {
 66		*apic_id = apic->local_apic_id;
 67		return 1;
 68	}
 69
 70	return 0;
 71}
 72
 73static int map_lsapic_id(struct acpi_subtable_header *entry,
 74		int device_declaration, u32 acpi_id, int *apic_id)
 75{
 76	struct acpi_madt_local_sapic *lsapic =
 77		(struct acpi_madt_local_sapic *)entry;
 78
 79	if (!(lsapic->lapic_flags & ACPI_MADT_ENABLED))
 80		return 0;
 81
 82	if (device_declaration) {
 83		if ((entry->length < 16) || (lsapic->uid != acpi_id))
 84			return 0;
 85	} else if (lsapic->processor_id != acpi_id)
 86		return 0;
 87
 88	*apic_id = (lsapic->id << 8) | lsapic->eid;
 89	return 1;
 90}
 91
 92static int map_madt_entry(int type, u32 acpi_id)
 
 
 
 
 93{
 94	unsigned long madt_end, entry;
 95	static struct acpi_table_madt *madt;
 96	static int read_madt;
 97	int apic_id = -1;
 98
 99	if (!read_madt) {
100		if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0,
101					(struct acpi_table_header **)&madt)))
102			madt = NULL;
103		read_madt++;
 
 
 
 
 
 
104	}
105
 
 
 
 
 
 
 
 
 
106	if (!madt)
107		return apic_id;
108
109	entry = (unsigned long)madt;
110	madt_end = entry + madt->header.length;
111
112	/* Parse all entries looking for a match. */
113
114	entry += sizeof(struct acpi_table_madt);
115	while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
116		struct acpi_subtable_header *header =
117			(struct acpi_subtable_header *)entry;
118		if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
119			if (map_lapic_id(header, acpi_id, &apic_id))
120				break;
121		} else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC) {
122			if (map_x2apic_id(header, type, acpi_id, &apic_id))
123				break;
124		} else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
125			if (map_lsapic_id(header, type, acpi_id, &apic_id))
 
 
 
126				break;
127		}
128		entry += header->length;
129	}
130	return apic_id;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
131}
132
133static int map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
134{
135	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
136	union acpi_object *obj;
137	struct acpi_subtable_header *header;
138	int apic_id = -1;
139
140	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
141		goto exit;
142
143	if (!buffer.length || !buffer.pointer)
144		goto exit;
145
146	obj = buffer.pointer;
147	if (obj->type != ACPI_TYPE_BUFFER ||
148	    obj->buffer.length < sizeof(struct acpi_subtable_header)) {
149		goto exit;
150	}
151
152	header = (struct acpi_subtable_header *)obj->buffer.pointer;
153	if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
154		map_lapic_id(header, acpi_id, &apic_id);
155	} else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
156		map_lsapic_id(header, type, acpi_id, &apic_id);
157	}
 
 
 
158
159exit:
160	if (buffer.pointer)
161		kfree(buffer.pointer);
162	return apic_id;
163}
164
165int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
 
 
 
 
 
 
 
 
 
 
 
 
166{
167#ifdef CONFIG_SMP
168	int i;
169#endif
170	int apic_id = -1;
171
172	apic_id = map_mat_entry(handle, type, acpi_id);
173	if (apic_id == -1)
174		apic_id = map_madt_entry(type, acpi_id);
175	if (apic_id == -1)
176		return apic_id;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
177
178#ifdef CONFIG_SMP
179	for_each_possible_cpu(i) {
180		if (cpu_physical_id(i) == apic_id)
181			return i;
182	}
183#else
184	/* In UP kernel, only processor 0 is valid */
185	if (apic_id == 0)
186		return apic_id;
187#endif
188	return -1;
189}
190EXPORT_SYMBOL_GPL(acpi_get_cpuid);
191
192static bool __init processor_physically_present(acpi_handle handle)
193{
194	int cpuid, type;
195	u32 acpi_id;
196	acpi_status status;
197	acpi_object_type acpi_type;
198	unsigned long long tmp;
199	union acpi_object object = { 0 };
200	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
201
202	status = acpi_get_type(handle, &acpi_type);
203	if (ACPI_FAILURE(status))
204		return false;
205
206	switch (acpi_type) {
207	case ACPI_TYPE_PROCESSOR:
208		status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
209		if (ACPI_FAILURE(status))
210			return false;
211		acpi_id = object.processor.proc_id;
212		break;
213	case ACPI_TYPE_DEVICE:
214		status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
215		if (ACPI_FAILURE(status))
216			return false;
217		acpi_id = tmp;
218		break;
219	default:
220		return false;
221	}
222
223	type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
224	cpuid = acpi_get_cpuid(handle, type, acpi_id);
225
226	if (cpuid == -1)
227		return false;
228
229	return true;
230}
 
231
232static void __cpuinit acpi_set_pdc_bits(u32 *buf)
 
 
233{
234	buf[0] = ACPI_PDC_REVISION_ID;
235	buf[1] = 1;
236
237	/* Enable coordination with firmware's _TSD info */
238	buf[2] = ACPI_PDC_SMP_T_SWCOORD;
239
240	/* Twiddle arch-specific bits needed for _PDC */
241	arch_acpi_set_pdc_bits(buf);
 
242}
243
244static struct acpi_object_list *__cpuinit acpi_processor_alloc_pdc(void)
245{
246	struct acpi_object_list *obj_list;
247	union acpi_object *obj;
248	u32 *buf;
 
249
250	/* allocate and initialize pdc. It will be used later. */
251	obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL);
252	if (!obj_list) {
253		printk(KERN_ERR "Memory allocation error\n");
254		return NULL;
255	}
256
257	obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
258	if (!obj) {
259		printk(KERN_ERR "Memory allocation error\n");
260		kfree(obj_list);
261		return NULL;
262	}
263
264	buf = kmalloc(12, GFP_KERNEL);
265	if (!buf) {
266		printk(KERN_ERR "Memory allocation error\n");
267		kfree(obj);
268		kfree(obj_list);
269		return NULL;
 
 
 
270	}
271
272	acpi_set_pdc_bits(buf);
273
274	obj->type = ACPI_TYPE_BUFFER;
275	obj->buffer.length = 12;
276	obj->buffer.pointer = (u8 *) buf;
277	obj_list->count = 1;
278	obj_list->pointer = obj;
279
280	return obj_list;
281}
282
283/*
284 * _PDC is required for a BIOS-OS handshake for most of the newer
285 * ACPI processor features.
286 */
287static int __cpuinit
288acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
289{
290	acpi_status status = AE_OK;
291
292	if (boot_option_idle_override == IDLE_NOMWAIT) {
293		/*
294		 * If mwait is disabled for CPU C-states, the C2C3_FFH access
295		 * mode will be disabled in the parameter of _PDC object.
296		 * Of course C1_FFH access mode will also be disabled.
297		 */
298		union acpi_object *obj;
299		u32 *buffer = NULL;
300
301		obj = pdc_in->pointer;
302		buffer = (u32 *)(obj->buffer.pointer);
303		buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH);
304
305	}
306	status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL);
307
308	if (ACPI_FAILURE(status))
309		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
310		    "Could not evaluate _PDC, using legacy perf. control.\n"));
311
312	return status;
313}
314
315void __cpuinit acpi_processor_set_pdc(acpi_handle handle)
316{
317	struct acpi_object_list *obj_list;
318
319	if (arch_has_acpi_pdc() == false)
320		return;
321
322	obj_list = acpi_processor_alloc_pdc();
323	if (!obj_list)
324		return;
 
325
326	acpi_processor_eval_pdc(handle, obj_list);
 
 
327
328	kfree(obj_list->pointer->buffer.pointer);
329	kfree(obj_list->pointer);
330	kfree(obj_list);
331}
332
333static acpi_status __init
334early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
 
 
 
 
 
 
 
 
 
 
335{
336	if (processor_physically_present(handle) == false)
337		return AE_OK;
338
339	acpi_processor_set_pdc(handle);
340	return AE_OK;
341}
342
343void __init acpi_early_processor_set_pdc(void)
344{
345	/*
346	 * Check whether the system is DMI table. If yes, OSPM
347	 * should not use mwait for CPU-states.
348	 */
349	dmi_check_system(processor_idle_dmi_table);
350
351	acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
352			    ACPI_UINT32_MAX,
353			    early_init_pdc, NULL, NULL, NULL);
354	acpi_get_devices("ACPI0007", early_init_pdc, NULL, NULL);
355}
v5.4
  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 */