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v3.5.6
  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/export.h>
 11#include <linux/dmi.h>
 12#include <linux/slab.h>
 13
 14#include <acpi/acpi_drivers.h>
 15#include <acpi/processor.h>
 16
 17#include "internal.h"
 18
 19#define PREFIX			"ACPI: "
 20#define _COMPONENT		ACPI_PROCESSOR_COMPONENT
 21ACPI_MODULE_NAME("processor_core");
 22
 23static int __init set_no_mwait(const struct dmi_system_id *id)
 24{
 25	printk(KERN_NOTICE PREFIX "%s detected - "
 26		"disabling mwait for CPU C-states\n", id->ident);
 27	boot_option_idle_override = IDLE_NOMWAIT;
 28	return 0;
 29}
 30
 31static struct dmi_system_id __initdata processor_idle_dmi_table[] = {
 32	{
 33	set_no_mwait, "Extensa 5220", {
 34	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
 35	DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
 36	DMI_MATCH(DMI_PRODUCT_VERSION, "0100"),
 37	DMI_MATCH(DMI_BOARD_NAME, "Columbia") }, NULL},
 38	{},
 39};
 40
 41static int map_lapic_id(struct acpi_subtable_header *entry,
 42		 u32 acpi_id, int *apic_id)
 43{
 44	struct acpi_madt_local_apic *lapic =
 45		(struct acpi_madt_local_apic *)entry;
 46
 47	if (!(lapic->lapic_flags & ACPI_MADT_ENABLED))
 48		return 0;
 49
 50	if (lapic->processor_id != acpi_id)
 51		return 0;
 52
 53	*apic_id = lapic->id;
 54	return 1;
 55}
 56
 57static int map_x2apic_id(struct acpi_subtable_header *entry,
 58			 int device_declaration, u32 acpi_id, int *apic_id)
 59{
 60	struct acpi_madt_local_x2apic *apic =
 61		(struct acpi_madt_local_x2apic *)entry;
 62
 63	if (!(apic->lapic_flags & ACPI_MADT_ENABLED))
 64		return 0;
 65
 66	if (device_declaration && (apic->uid == acpi_id)) {
 67		*apic_id = apic->local_apic_id;
 68		return 1;
 69	}
 70
 71	return 0;
 72}
 73
 74static int map_lsapic_id(struct acpi_subtable_header *entry,
 75		int device_declaration, u32 acpi_id, int *apic_id)
 76{
 77	struct acpi_madt_local_sapic *lsapic =
 78		(struct acpi_madt_local_sapic *)entry;
 79
 80	if (!(lsapic->lapic_flags & ACPI_MADT_ENABLED))
 81		return 0;
 82
 83	if (device_declaration) {
 84		if ((entry->length < 16) || (lsapic->uid != acpi_id))
 85			return 0;
 86	} else if (lsapic->processor_id != acpi_id)
 87		return 0;
 88
 89	*apic_id = (lsapic->id << 8) | lsapic->eid;
 90	return 1;
 91}
 92
 93static int map_madt_entry(int type, u32 acpi_id)
 
 
 
 
 94{
 95	unsigned long madt_end, entry;
 96	static struct acpi_table_madt *madt;
 97	static int read_madt;
 98	int apic_id = -1;
 99
100	if (!read_madt) {
101		if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0,
102					(struct acpi_table_header **)&madt)))
103			madt = NULL;
104		read_madt++;
 
 
 
 
 
 
105	}
106
 
 
 
 
 
 
 
 
 
 
107	if (!madt)
108		return apic_id;
109
110	entry = (unsigned long)madt;
111	madt_end = entry + madt->header.length;
112
113	/* Parse all entries looking for a match. */
114
115	entry += sizeof(struct acpi_table_madt);
116	while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
117		struct acpi_subtable_header *header =
118			(struct acpi_subtable_header *)entry;
119		if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
120			if (map_lapic_id(header, acpi_id, &apic_id))
121				break;
122		} else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC) {
123			if (map_x2apic_id(header, type, acpi_id, &apic_id))
124				break;
125		} else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
126			if (map_lsapic_id(header, type, acpi_id, &apic_id))
 
 
 
127				break;
128		}
129		entry += header->length;
130	}
131	return apic_id;
132}
133
134static int map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
135{
136	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
137	union acpi_object *obj;
138	struct acpi_subtable_header *header;
139	int apic_id = -1;
140
141	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
142		goto exit;
143
144	if (!buffer.length || !buffer.pointer)
145		goto exit;
146
147	obj = buffer.pointer;
148	if (obj->type != ACPI_TYPE_BUFFER ||
149	    obj->buffer.length < sizeof(struct acpi_subtable_header)) {
150		goto exit;
151	}
152
153	header = (struct acpi_subtable_header *)obj->buffer.pointer;
154	if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
155		map_lapic_id(header, acpi_id, &apic_id);
156	} else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
157		map_lsapic_id(header, type, acpi_id, &apic_id);
158	}
 
 
 
159
160exit:
161	if (buffer.pointer)
162		kfree(buffer.pointer);
163	return apic_id;
164}
165
166int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
 
 
 
 
 
 
 
 
 
 
 
167{
168#ifdef CONFIG_SMP
169	int i;
170#endif
171	int apic_id = -1;
172
173	apic_id = map_mat_entry(handle, type, acpi_id);
174	if (apic_id == -1)
175		apic_id = map_madt_entry(type, acpi_id);
176	if (apic_id == -1) {
177		/*
178		 * On UP processor, there is no _MAT or MADT table.
179		 * So above apic_id is always set to -1.
180		 *
181		 * BIOS may define multiple CPU handles even for UP processor.
182		 * For example,
183		 *
184		 * Scope (_PR)
185                 * {
186		 *     Processor (CPU0, 0x00, 0x00000410, 0x06) {}
187		 *     Processor (CPU1, 0x01, 0x00000410, 0x06) {}
188		 *     Processor (CPU2, 0x02, 0x00000410, 0x06) {}
189		 *     Processor (CPU3, 0x03, 0x00000410, 0x06) {}
190		 * }
191		 *
192		 * Ignores apic_id and always returns 0 for the processor
193		 * handle with acpi id 0 if nr_cpu_ids is 1.
194		 * This should be the case if SMP tables are not found.
195		 * Return -1 for other CPU's handle.
196		 */
197		if (nr_cpu_ids <= 1 && acpi_id == 0)
198			return acpi_id;
199		else
200			return apic_id;
201	}
202
203#ifdef CONFIG_SMP
204	for_each_possible_cpu(i) {
205		if (cpu_physical_id(i) == apic_id)
206			return i;
207	}
208#else
209	/* In UP kernel, only processor 0 is valid */
210	if (apic_id == 0)
211		return apic_id;
212#endif
213	return -1;
214}
215EXPORT_SYMBOL_GPL(acpi_get_cpuid);
216
217static bool __init processor_physically_present(acpi_handle handle)
218{
219	int cpuid, type;
220	u32 acpi_id;
221	acpi_status status;
222	acpi_object_type acpi_type;
223	unsigned long long tmp;
224	union acpi_object object = { 0 };
225	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
226
227	status = acpi_get_type(handle, &acpi_type);
228	if (ACPI_FAILURE(status))
229		return false;
230
231	switch (acpi_type) {
232	case ACPI_TYPE_PROCESSOR:
233		status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
234		if (ACPI_FAILURE(status))
235			return false;
236		acpi_id = object.processor.proc_id;
237		break;
238	case ACPI_TYPE_DEVICE:
239		status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
240		if (ACPI_FAILURE(status))
241			return false;
242		acpi_id = tmp;
243		break;
244	default:
245		return false;
246	}
247
248	type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
249	cpuid = acpi_get_cpuid(handle, type, acpi_id);
250
251	if (cpuid == -1)
252		return false;
253
254	return true;
255}
 
256
257static void __cpuinit acpi_set_pdc_bits(u32 *buf)
 
 
258{
259	buf[0] = ACPI_PDC_REVISION_ID;
260	buf[1] = 1;
261
262	/* Enable coordination with firmware's _TSD info */
263	buf[2] = ACPI_PDC_SMP_T_SWCOORD;
264
265	/* Twiddle arch-specific bits needed for _PDC */
266	arch_acpi_set_pdc_bits(buf);
 
267}
268
269static struct acpi_object_list *__cpuinit acpi_processor_alloc_pdc(void)
270{
271	struct acpi_object_list *obj_list;
272	union acpi_object *obj;
273	u32 *buf;
 
274
275	/* allocate and initialize pdc. It will be used later. */
276	obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL);
277	if (!obj_list) {
278		printk(KERN_ERR "Memory allocation error\n");
279		return NULL;
280	}
281
282	obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
283	if (!obj) {
284		printk(KERN_ERR "Memory allocation error\n");
285		kfree(obj_list);
286		return NULL;
287	}
288
289	buf = kmalloc(12, GFP_KERNEL);
290	if (!buf) {
291		printk(KERN_ERR "Memory allocation error\n");
292		kfree(obj);
293		kfree(obj_list);
294		return NULL;
 
 
 
295	}
296
297	acpi_set_pdc_bits(buf);
298
299	obj->type = ACPI_TYPE_BUFFER;
300	obj->buffer.length = 12;
301	obj->buffer.pointer = (u8 *) buf;
302	obj_list->count = 1;
303	obj_list->pointer = obj;
304
305	return obj_list;
306}
307
308/*
309 * _PDC is required for a BIOS-OS handshake for most of the newer
310 * ACPI processor features.
311 */
312static int __cpuinit
313acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
314{
315	acpi_status status = AE_OK;
316
317	if (boot_option_idle_override == IDLE_NOMWAIT) {
318		/*
319		 * If mwait is disabled for CPU C-states, the C2C3_FFH access
320		 * mode will be disabled in the parameter of _PDC object.
321		 * Of course C1_FFH access mode will also be disabled.
322		 */
323		union acpi_object *obj;
324		u32 *buffer = NULL;
325
326		obj = pdc_in->pointer;
327		buffer = (u32 *)(obj->buffer.pointer);
328		buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH);
329
330	}
331	status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL);
332
333	if (ACPI_FAILURE(status))
334		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
335		    "Could not evaluate _PDC, using legacy perf. control.\n"));
336
337	return status;
338}
339
340void __cpuinit acpi_processor_set_pdc(acpi_handle handle)
341{
342	struct acpi_object_list *obj_list;
343
344	if (arch_has_acpi_pdc() == false)
345		return;
346
347	obj_list = acpi_processor_alloc_pdc();
348	if (!obj_list)
349		return;
 
350
351	acpi_processor_eval_pdc(handle, obj_list);
 
 
352
353	kfree(obj_list->pointer->buffer.pointer);
354	kfree(obj_list->pointer);
355	kfree(obj_list);
356}
357
358static acpi_status __init
359early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
 
 
 
 
 
 
 
 
 
 
360{
361	if (processor_physically_present(handle) == false)
362		return AE_OK;
363
364	acpi_processor_set_pdc(handle);
365	return AE_OK;
366}
367
368void __init acpi_early_processor_set_pdc(void)
369{
370	/*
371	 * Check whether the system is DMI table. If yes, OSPM
372	 * should not use mwait for CPU-states.
373	 */
374	dmi_check_system(processor_idle_dmi_table);
375
376	acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
377			    ACPI_UINT32_MAX,
378			    early_init_pdc, NULL, NULL, NULL);
379	acpi_get_devices("ACPI0007", early_init_pdc, NULL, NULL);
380}
v4.6
  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(int type, u32 acpi_id)
112{
113	unsigned long madt_end, entry;
114	phys_cpuid_t phys_id = PHYS_CPUID_INVALID;	/* CPU hardware ID */
115	struct acpi_table_madt *madt;
116
117	madt = get_madt_table();
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
148static phys_cpuid_t map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
149{
150	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
151	union acpi_object *obj;
152	struct acpi_subtable_header *header;
153	phys_cpuid_t phys_id = PHYS_CPUID_INVALID;
154
155	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
156		goto exit;
157
158	if (!buffer.length || !buffer.pointer)
159		goto exit;
160
161	obj = buffer.pointer;
162	if (obj->type != ACPI_TYPE_BUFFER ||
163	    obj->buffer.length < sizeof(struct acpi_subtable_header)) {
164		goto exit;
165	}
166
167	header = (struct acpi_subtable_header *)obj->buffer.pointer;
168	if (header->type == ACPI_MADT_TYPE_LOCAL_APIC)
169		map_lapic_id(header, acpi_id, &phys_id);
170	else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC)
171		map_lsapic_id(header, type, acpi_id, &phys_id);
172	else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC)
173		map_x2apic_id(header, type, acpi_id, &phys_id);
174	else if (header->type == ACPI_MADT_TYPE_GENERIC_INTERRUPT)
175		map_gicc_mpidr(header, type, acpi_id, &phys_id);
176
177exit:
178	kfree(buffer.pointer);
179	return phys_id;
 
180}
181
182phys_cpuid_t acpi_get_phys_id(acpi_handle handle, int type, u32 acpi_id)
183{
184	phys_cpuid_t phys_id;
185
186	phys_id = map_mat_entry(handle, type, acpi_id);
187	if (invalid_phys_cpuid(phys_id))
188		phys_id = map_madt_entry(type, acpi_id);
189
190	return phys_id;
191}
192
193int acpi_map_cpuid(phys_cpuid_t phys_id, u32 acpi_id)
194{
195#ifdef CONFIG_SMP
196	int i;
197#endif
 
198
199	if (invalid_phys_cpuid(phys_id)) {
 
 
 
200		/*
201		 * On UP processor, there is no _MAT or MADT table.
202		 * So above phys_id is always set to PHYS_CPUID_INVALID.
203		 *
204		 * BIOS may define multiple CPU handles even for UP processor.
205		 * For example,
206		 *
207		 * Scope (_PR)
208		 * {
209		 *     Processor (CPU0, 0x00, 0x00000410, 0x06) {}
210		 *     Processor (CPU1, 0x01, 0x00000410, 0x06) {}
211		 *     Processor (CPU2, 0x02, 0x00000410, 0x06) {}
212		 *     Processor (CPU3, 0x03, 0x00000410, 0x06) {}
213		 * }
214		 *
215		 * Ignores phys_id and always returns 0 for the processor
216		 * handle with acpi id 0 if nr_cpu_ids is 1.
217		 * This should be the case if SMP tables are not found.
218		 * Return -EINVAL for other CPU's handle.
219		 */
220		if (nr_cpu_ids <= 1 && acpi_id == 0)
221			return acpi_id;
222		else
223			return -EINVAL;
224	}
225
226#ifdef CONFIG_SMP
227	for_each_possible_cpu(i) {
228		if (cpu_physical_id(i) == phys_id)
229			return i;
230	}
231#else
232	/* In UP kernel, only processor 0 is valid */
233	if (phys_id == 0)
234		return phys_id;
235#endif
236	return -ENODEV;
237}
 
238
239int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
240{
241	phys_cpuid_t phys_id;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
242
243	phys_id = acpi_get_phys_id(handle, type, acpi_id);
 
244
245	return acpi_map_cpuid(phys_id, acpi_id);
 
 
 
246}
247EXPORT_SYMBOL_GPL(acpi_get_cpuid);
248
249#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
250static int get_ioapic_id(struct acpi_subtable_header *entry, u32 gsi_base,
251			 u64 *phys_addr, int *ioapic_id)
252{
253	struct acpi_madt_io_apic *ioapic = (struct acpi_madt_io_apic *)entry;
 
254
255	if (ioapic->global_irq_base != gsi_base)
256		return 0;
257
258	*phys_addr = ioapic->address;
259	*ioapic_id = ioapic->id;
260	return 1;
261}
262
263static int parse_madt_ioapic_entry(u32 gsi_base, u64 *phys_addr)
264{
265	struct acpi_subtable_header *hdr;
266	unsigned long madt_end, entry;
267	struct acpi_table_madt *madt;
268	int apic_id = -1;
269
270	madt = get_madt_table();
271	if (!madt)
272		return apic_id;
 
 
 
273
274	entry = (unsigned long)madt;
275	madt_end = entry + madt->header.length;
 
 
 
 
276
277	/* Parse all entries looking for a match. */
278	entry += sizeof(struct acpi_table_madt);
279	while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
280		hdr = (struct acpi_subtable_header *)entry;
281		if (hdr->type == ACPI_MADT_TYPE_IO_APIC &&
282		    get_ioapic_id(hdr, gsi_base, phys_addr, &apic_id))
283			break;
284		else
285			entry += hdr->length;
286	}
287
288	return apic_id;
 
 
 
 
 
 
 
 
289}
290
291static int parse_mat_ioapic_entry(acpi_handle handle, u32 gsi_base,
292				  u64 *phys_addr)
 
 
 
 
293{
294	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
295	struct acpi_subtable_header *header;
296	union acpi_object *obj;
297	int apic_id = -1;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
298
299	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
300		goto exit;
 
301
302	if (!buffer.length || !buffer.pointer)
303		goto exit;
304
305	obj = buffer.pointer;
306	if (obj->type != ACPI_TYPE_BUFFER ||
307	    obj->buffer.length < sizeof(struct acpi_subtable_header))
308		goto exit;
309
310	header = (struct acpi_subtable_header *)obj->buffer.pointer;
311	if (header->type == ACPI_MADT_TYPE_IO_APIC)
312		get_ioapic_id(header, gsi_base, phys_addr, &apic_id);
313
314exit:
315	kfree(buffer.pointer);
316	return apic_id;
317}
318
319/**
320 * acpi_get_ioapic_id - Get IOAPIC ID and physical address matching @gsi_base
321 * @handle:	ACPI object for IOAPIC device
322 * @gsi_base:	GSI base to match with
323 * @phys_addr:	Pointer to store physical address of matching IOAPIC record
324 *
325 * Walk resources returned by ACPI_MAT method, then ACPI MADT table, to search
326 * for an ACPI IOAPIC record matching @gsi_base.
327 * Return IOAPIC id and store physical address in @phys_addr if found a match,
328 * otherwise return <0.
329 */
330int acpi_get_ioapic_id(acpi_handle handle, u32 gsi_base, u64 *phys_addr)
331{
332	int apic_id;
 
 
 
 
 
333
334	apic_id = parse_mat_ioapic_entry(handle, gsi_base, phys_addr);
335	if (apic_id == -1)
336		apic_id = parse_madt_ioapic_entry(gsi_base, phys_addr);
 
 
 
 
337
338	return apic_id;
 
 
 
339}
340#endif /* CONFIG_ACPI_HOTPLUG_IOAPIC */