aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/acpi/processor_core.c
blob: e32321ce9a5cfbc4a80e7101b2784506ff057fc6 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
/*
 * Copyright (C) 2005 Intel Corporation
 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
 *
 *	Alex Chiang <achiang@hp.com>
 *	- Unified x86/ia64 implementations
 */
#include <linux/export.h>
#include <linux/acpi.h>
#include <acpi/processor.h>

#define _COMPONENT		ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("processor_core");

static int map_lapic_id(struct acpi_subtable_header *entry,
		 u32 acpi_id, int *apic_id)
{
	struct acpi_madt_local_apic *lapic =
		(struct acpi_madt_local_apic *)entry;

	if (!(lapic->lapic_flags & ACPI_MADT_ENABLED))
		return -ENODEV;

	if (lapic->processor_id != acpi_id)
		return -EINVAL;

	*apic_id = lapic->id;
	return 0;
}

static int map_x2apic_id(struct acpi_subtable_header *entry,
			 int device_declaration, u32 acpi_id, int *apic_id)
{
	struct acpi_madt_local_x2apic *apic =
		(struct acpi_madt_local_x2apic *)entry;

	if (!(apic->lapic_flags & ACPI_MADT_ENABLED))
		return -ENODEV;

	if (device_declaration && (apic->uid == acpi_id)) {
		*apic_id = apic->local_apic_id;
		return 0;
	}

	return -EINVAL;
}

static int map_lsapic_id(struct acpi_subtable_header *entry,
		int device_declaration, u32 acpi_id, int *apic_id)
{
	struct acpi_madt_local_sapic *lsapic =
		(struct acpi_madt_local_sapic *)entry;

	if (!(lsapic->lapic_flags & ACPI_MADT_ENABLED))
		return -ENODEV;

	if (device_declaration) {
		if ((entry->length < 16) || (lsapic->uid != acpi_id))
			return -EINVAL;
	} else if (lsapic->processor_id != acpi_id)
		return -EINVAL;

	*apic_id = (lsapic->id << 8) | lsapic->eid;
	return 0;
}

static int map_madt_entry(int type, u32 acpi_id)
{
	unsigned long madt_end, entry;
	static struct acpi_table_madt *madt;
	static int read_madt;
	int apic_id = -1;

	if (!read_madt) {
		if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0,
					(struct acpi_table_header **)&madt)))
			madt = NULL;
		read_madt++;
	}

	if (!madt)
		return apic_id;

	entry = (unsigned long)madt;
	madt_end = entry + madt->header.length;

	/* Parse all entries looking for a match. */

	entry += sizeof(struct acpi_table_madt);
	while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
		struct acpi_subtable_header *header =
			(struct acpi_subtable_header *)entry;
		if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
			if (!map_lapic_id(header, acpi_id, &apic_id))
				break;
		} else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC) {
			if (!map_x2apic_id(header, type, acpi_id, &apic_id))
				break;
		} else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
			if (!map_lsapic_id(header, type, acpi_id, &apic_id))
				break;
		}
		entry += header->length;
	}
	return apic_id;
}

static int map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
{
	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
	union acpi_object *obj;
	struct acpi_subtable_header *header;
	int apic_id = -1;

	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
		goto exit;

	if (!buffer.length || !buffer.pointer)
		goto exit;

	obj = buffer.pointer;
	if (obj->type != ACPI_TYPE_BUFFER ||
	    obj->buffer.length < sizeof(struct acpi_subtable_header)) {
		goto exit;
	}

	header = (struct acpi_subtable_header *)obj->buffer.pointer;
	if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
		map_lapic_id(header, acpi_id, &apic_id);
	} else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
		map_lsapic_id(header, type, acpi_id, &apic_id);
	} else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC) {
		map_x2apic_id(header, type, acpi_id, &apic_id);
	}

exit:
	kfree(buffer.pointer);
	return apic_id;
}

int acpi_get_apicid(acpi_handle handle, int type, u32 acpi_id)
{
	int apic_id;

	apic_id = map_mat_entry(handle, type, acpi_id);
	if (apic_id == -1)
		apic_id = map_madt_entry(type, acpi_id);

	return apic_id;
}

int acpi_map_cpuid(int apic_id, u32 acpi_id)
{
#ifdef CONFIG_SMP
	int i;
#endif

	if (apic_id == -1) {
		/*
		 * On UP processor, there is no _MAT or MADT table.
		 * So above apic_id is always set to -1.
		 *
		 * BIOS may define multiple CPU handles even for UP processor.
		 * For example,
		 *
		 * Scope (_PR)
                 * {
		 *     Processor (CPU0, 0x00, 0x00000410, 0x06) {}
		 *     Processor (CPU1, 0x01, 0x00000410, 0x06) {}
		 *     Processor (CPU2, 0x02, 0x00000410, 0x06) {}
		 *     Processor (CPU3, 0x03, 0x00000410, 0x06) {}
		 * }
		 *
		 * Ignores apic_id and always returns 0 for the processor
		 * handle with acpi id 0 if nr_cpu_ids is 1.
		 * This should be the case if SMP tables are not found.
		 * Return -1 for other CPU's handle.
		 */
		if (nr_cpu_ids <= 1 && acpi_id == 0)
			return acpi_id;
		else
			return apic_id;
	}

#ifdef CONFIG_SMP
	for_each_possible_cpu(i) {
		if (cpu_physical_id(i) == apic_id)
			return i;
	}
#else
	/* In UP kernel, only processor 0 is valid */
	if (apic_id == 0)
		return apic_id;
#endif
	return -1;
}

int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
{
	int apic_id;

	apic_id = acpi_get_apicid(handle, type, acpi_id);

	return acpi_map_cpuid(apic_id, acpi_id);
}
EXPORT_SYMBOL_GPL(acpi_get_cpuid);