xref: /linux/drivers/acpi/processor_core.c (revision e0bf6c5ca2d3281f231c5f0c9bf145e9513644de)
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
17 ACPI_MODULE_NAME("processor_core");
18 
19 static 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 
34 static int map_lapic_id(struct acpi_subtable_header *entry,
35 		 u32 acpi_id, int *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 
50 static int map_x2apic_id(struct acpi_subtable_header *entry,
51 			 int device_declaration, u32 acpi_id, int *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 
67 static int map_lsapic_id(struct acpi_subtable_header *entry,
68 		int device_declaration, u32 acpi_id, int *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 static int map_madt_entry(int type, u32 acpi_id)
87 {
88 	unsigned long madt_end, entry;
89 	int phys_id = -1;	/* CPU hardware ID */
90 	struct acpi_table_madt *madt;
91 
92 	madt = get_madt_table();
93 	if (!madt)
94 		return phys_id;
95 
96 	entry = (unsigned long)madt;
97 	madt_end = entry + madt->header.length;
98 
99 	/* Parse all entries looking for a match. */
100 
101 	entry += sizeof(struct acpi_table_madt);
102 	while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
103 		struct acpi_subtable_header *header =
104 			(struct acpi_subtable_header *)entry;
105 		if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
106 			if (!map_lapic_id(header, acpi_id, &phys_id))
107 				break;
108 		} else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC) {
109 			if (!map_x2apic_id(header, type, acpi_id, &phys_id))
110 				break;
111 		} else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
112 			if (!map_lsapic_id(header, type, acpi_id, &phys_id))
113 				break;
114 		}
115 		entry += header->length;
116 	}
117 	return phys_id;
118 }
119 
120 static int map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
121 {
122 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
123 	union acpi_object *obj;
124 	struct acpi_subtable_header *header;
125 	int phys_id = -1;
126 
127 	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
128 		goto exit;
129 
130 	if (!buffer.length || !buffer.pointer)
131 		goto exit;
132 
133 	obj = buffer.pointer;
134 	if (obj->type != ACPI_TYPE_BUFFER ||
135 	    obj->buffer.length < sizeof(struct acpi_subtable_header)) {
136 		goto exit;
137 	}
138 
139 	header = (struct acpi_subtable_header *)obj->buffer.pointer;
140 	if (header->type == ACPI_MADT_TYPE_LOCAL_APIC)
141 		map_lapic_id(header, acpi_id, &phys_id);
142 	else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC)
143 		map_lsapic_id(header, type, acpi_id, &phys_id);
144 	else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC)
145 		map_x2apic_id(header, type, acpi_id, &phys_id);
146 
147 exit:
148 	kfree(buffer.pointer);
149 	return phys_id;
150 }
151 
152 int acpi_get_phys_id(acpi_handle handle, int type, u32 acpi_id)
153 {
154 	int phys_id;
155 
156 	phys_id = map_mat_entry(handle, type, acpi_id);
157 	if (phys_id == -1)
158 		phys_id = map_madt_entry(type, acpi_id);
159 
160 	return phys_id;
161 }
162 
163 int acpi_map_cpuid(int phys_id, u32 acpi_id)
164 {
165 #ifdef CONFIG_SMP
166 	int i;
167 #endif
168 
169 	if (phys_id == -1) {
170 		/*
171 		 * On UP processor, there is no _MAT or MADT table.
172 		 * So above phys_id is always set to -1.
173 		 *
174 		 * BIOS may define multiple CPU handles even for UP processor.
175 		 * For example,
176 		 *
177 		 * Scope (_PR)
178 		 * {
179 		 *     Processor (CPU0, 0x00, 0x00000410, 0x06) {}
180 		 *     Processor (CPU1, 0x01, 0x00000410, 0x06) {}
181 		 *     Processor (CPU2, 0x02, 0x00000410, 0x06) {}
182 		 *     Processor (CPU3, 0x03, 0x00000410, 0x06) {}
183 		 * }
184 		 *
185 		 * Ignores phys_id and always returns 0 for the processor
186 		 * handle with acpi id 0 if nr_cpu_ids is 1.
187 		 * This should be the case if SMP tables are not found.
188 		 * Return -1 for other CPU's handle.
189 		 */
190 		if (nr_cpu_ids <= 1 && acpi_id == 0)
191 			return acpi_id;
192 		else
193 			return phys_id;
194 	}
195 
196 #ifdef CONFIG_SMP
197 	for_each_possible_cpu(i) {
198 		if (cpu_physical_id(i) == phys_id)
199 			return i;
200 	}
201 #else
202 	/* In UP kernel, only processor 0 is valid */
203 	if (phys_id == 0)
204 		return phys_id;
205 #endif
206 	return -1;
207 }
208 
209 int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
210 {
211 	int phys_id;
212 
213 	phys_id = acpi_get_phys_id(handle, type, acpi_id);
214 
215 	return acpi_map_cpuid(phys_id, acpi_id);
216 }
217 EXPORT_SYMBOL_GPL(acpi_get_cpuid);
218 
219 #ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
220 static int get_ioapic_id(struct acpi_subtable_header *entry, u32 gsi_base,
221 			 u64 *phys_addr, int *ioapic_id)
222 {
223 	struct acpi_madt_io_apic *ioapic = (struct acpi_madt_io_apic *)entry;
224 
225 	if (ioapic->global_irq_base != gsi_base)
226 		return 0;
227 
228 	*phys_addr = ioapic->address;
229 	*ioapic_id = ioapic->id;
230 	return 1;
231 }
232 
233 static int parse_madt_ioapic_entry(u32 gsi_base, u64 *phys_addr)
234 {
235 	struct acpi_subtable_header *hdr;
236 	unsigned long madt_end, entry;
237 	struct acpi_table_madt *madt;
238 	int apic_id = -1;
239 
240 	madt = get_madt_table();
241 	if (!madt)
242 		return apic_id;
243 
244 	entry = (unsigned long)madt;
245 	madt_end = entry + madt->header.length;
246 
247 	/* Parse all entries looking for a match. */
248 	entry += sizeof(struct acpi_table_madt);
249 	while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
250 		hdr = (struct acpi_subtable_header *)entry;
251 		if (hdr->type == ACPI_MADT_TYPE_IO_APIC &&
252 		    get_ioapic_id(hdr, gsi_base, phys_addr, &apic_id))
253 			break;
254 		else
255 			entry += hdr->length;
256 	}
257 
258 	return apic_id;
259 }
260 
261 static int parse_mat_ioapic_entry(acpi_handle handle, u32 gsi_base,
262 				  u64 *phys_addr)
263 {
264 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
265 	struct acpi_subtable_header *header;
266 	union acpi_object *obj;
267 	int apic_id = -1;
268 
269 	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
270 		goto exit;
271 
272 	if (!buffer.length || !buffer.pointer)
273 		goto exit;
274 
275 	obj = buffer.pointer;
276 	if (obj->type != ACPI_TYPE_BUFFER ||
277 	    obj->buffer.length < sizeof(struct acpi_subtable_header))
278 		goto exit;
279 
280 	header = (struct acpi_subtable_header *)obj->buffer.pointer;
281 	if (header->type == ACPI_MADT_TYPE_IO_APIC)
282 		get_ioapic_id(header, gsi_base, phys_addr, &apic_id);
283 
284 exit:
285 	kfree(buffer.pointer);
286 	return apic_id;
287 }
288 
289 /**
290  * acpi_get_ioapic_id - Get IOAPIC ID and physical address matching @gsi_base
291  * @handle:	ACPI object for IOAPIC device
292  * @gsi_base:	GSI base to match with
293  * @phys_addr:	Pointer to store physical address of matching IOAPIC record
294  *
295  * Walk resources returned by ACPI_MAT method, then ACPI MADT table, to search
296  * for an ACPI IOAPIC record matching @gsi_base.
297  * Return IOAPIC id and store physical address in @phys_addr if found a match,
298  * otherwise return <0.
299  */
300 int acpi_get_ioapic_id(acpi_handle handle, u32 gsi_base, u64 *phys_addr)
301 {
302 	int apic_id;
303 
304 	apic_id = parse_mat_ioapic_entry(handle, gsi_base, phys_addr);
305 	if (apic_id == -1)
306 		apic_id = parse_madt_ioapic_entry(gsi_base, phys_addr);
307 
308 	return apic_id;
309 }
310 #endif /* CONFIG_ACPI_HOTPLUG_IOAPIC */
311