xref: /openbmc/linux/drivers/acpi/processor_core.c (revision b830f94f)
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
18 ACPI_MODULE_NAME("processor_core");
19 
20 static 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 
35 static 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 
51 static 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 
68 static 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  */
90 static 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 
112 static 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 
148 phys_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 
165 static 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 
194 exit:
195 	kfree(buffer.pointer);
196 	return phys_id;
197 }
198 
199 phys_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 }
209 EXPORT_SYMBOL_GPL(acpi_get_phys_id);
210 
211 int 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 
257 int 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 }
265 EXPORT_SYMBOL_GPL(acpi_get_cpuid);
266 
267 #ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
268 static 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 
281 static 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 
309 static 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 
332 exit:
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  */
348 int 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 */
359