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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}
v4.17
  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 */