xref: /openbmc/linux/drivers/acpi/processor_core.c (revision e23feb16)
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
21 ACPI_MODULE_NAME("processor_core");
22 
23 static 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 
31 static struct dmi_system_id processor_idle_dmi_table[] __initdata = {
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 
41 static 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 
57 static 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 
74 static 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 
93 static 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 
134 static 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 
160 exit:
161 	kfree(buffer.pointer);
162 	return apic_id;
163 }
164 
165 int 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 		/*
177 		 * On UP processor, there is no _MAT or MADT table.
178 		 * So above apic_id is always set to -1.
179 		 *
180 		 * BIOS may define multiple CPU handles even for UP processor.
181 		 * For example,
182 		 *
183 		 * Scope (_PR)
184                  * {
185 		 *     Processor (CPU0, 0x00, 0x00000410, 0x06) {}
186 		 *     Processor (CPU1, 0x01, 0x00000410, 0x06) {}
187 		 *     Processor (CPU2, 0x02, 0x00000410, 0x06) {}
188 		 *     Processor (CPU3, 0x03, 0x00000410, 0x06) {}
189 		 * }
190 		 *
191 		 * Ignores apic_id and always returns 0 for the processor
192 		 * handle with acpi id 0 if nr_cpu_ids is 1.
193 		 * This should be the case if SMP tables are not found.
194 		 * Return -1 for other CPU's handle.
195 		 */
196 		if (nr_cpu_ids <= 1 && acpi_id == 0)
197 			return acpi_id;
198 		else
199 			return apic_id;
200 	}
201 
202 #ifdef CONFIG_SMP
203 	for_each_possible_cpu(i) {
204 		if (cpu_physical_id(i) == apic_id)
205 			return i;
206 	}
207 #else
208 	/* In UP kernel, only processor 0 is valid */
209 	if (apic_id == 0)
210 		return apic_id;
211 #endif
212 	return -1;
213 }
214 EXPORT_SYMBOL_GPL(acpi_get_cpuid);
215 
216 static bool __init processor_physically_present(acpi_handle handle)
217 {
218 	int cpuid, type;
219 	u32 acpi_id;
220 	acpi_status status;
221 	acpi_object_type acpi_type;
222 	unsigned long long tmp;
223 	union acpi_object object = { 0 };
224 	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
225 
226 	status = acpi_get_type(handle, &acpi_type);
227 	if (ACPI_FAILURE(status))
228 		return false;
229 
230 	switch (acpi_type) {
231 	case ACPI_TYPE_PROCESSOR:
232 		status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
233 		if (ACPI_FAILURE(status))
234 			return false;
235 		acpi_id = object.processor.proc_id;
236 		break;
237 	case ACPI_TYPE_DEVICE:
238 		status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
239 		if (ACPI_FAILURE(status))
240 			return false;
241 		acpi_id = tmp;
242 		break;
243 	default:
244 		return false;
245 	}
246 
247 	type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
248 	cpuid = acpi_get_cpuid(handle, type, acpi_id);
249 
250 	if (cpuid == -1)
251 		return false;
252 
253 	return true;
254 }
255 
256 static void acpi_set_pdc_bits(u32 *buf)
257 {
258 	buf[0] = ACPI_PDC_REVISION_ID;
259 	buf[1] = 1;
260 
261 	/* Enable coordination with firmware's _TSD info */
262 	buf[2] = ACPI_PDC_SMP_T_SWCOORD;
263 
264 	/* Twiddle arch-specific bits needed for _PDC */
265 	arch_acpi_set_pdc_bits(buf);
266 }
267 
268 static struct acpi_object_list *acpi_processor_alloc_pdc(void)
269 {
270 	struct acpi_object_list *obj_list;
271 	union acpi_object *obj;
272 	u32 *buf;
273 
274 	/* allocate and initialize pdc. It will be used later. */
275 	obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL);
276 	if (!obj_list) {
277 		printk(KERN_ERR "Memory allocation error\n");
278 		return NULL;
279 	}
280 
281 	obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
282 	if (!obj) {
283 		printk(KERN_ERR "Memory allocation error\n");
284 		kfree(obj_list);
285 		return NULL;
286 	}
287 
288 	buf = kmalloc(12, GFP_KERNEL);
289 	if (!buf) {
290 		printk(KERN_ERR "Memory allocation error\n");
291 		kfree(obj);
292 		kfree(obj_list);
293 		return NULL;
294 	}
295 
296 	acpi_set_pdc_bits(buf);
297 
298 	obj->type = ACPI_TYPE_BUFFER;
299 	obj->buffer.length = 12;
300 	obj->buffer.pointer = (u8 *) buf;
301 	obj_list->count = 1;
302 	obj_list->pointer = obj;
303 
304 	return obj_list;
305 }
306 
307 /*
308  * _PDC is required for a BIOS-OS handshake for most of the newer
309  * ACPI processor features.
310  */
311 static int
312 acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
313 {
314 	acpi_status status = AE_OK;
315 
316 	if (boot_option_idle_override == IDLE_NOMWAIT) {
317 		/*
318 		 * If mwait is disabled for CPU C-states, the C2C3_FFH access
319 		 * mode will be disabled in the parameter of _PDC object.
320 		 * Of course C1_FFH access mode will also be disabled.
321 		 */
322 		union acpi_object *obj;
323 		u32 *buffer = NULL;
324 
325 		obj = pdc_in->pointer;
326 		buffer = (u32 *)(obj->buffer.pointer);
327 		buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH);
328 
329 	}
330 	status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL);
331 
332 	if (ACPI_FAILURE(status))
333 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
334 		    "Could not evaluate _PDC, using legacy perf. control.\n"));
335 
336 	return status;
337 }
338 
339 void acpi_processor_set_pdc(acpi_handle handle)
340 {
341 	struct acpi_object_list *obj_list;
342 
343 	if (arch_has_acpi_pdc() == false)
344 		return;
345 
346 	obj_list = acpi_processor_alloc_pdc();
347 	if (!obj_list)
348 		return;
349 
350 	acpi_processor_eval_pdc(handle, obj_list);
351 
352 	kfree(obj_list->pointer->buffer.pointer);
353 	kfree(obj_list->pointer);
354 	kfree(obj_list);
355 }
356 
357 static acpi_status __init
358 early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
359 {
360 	if (processor_physically_present(handle) == false)
361 		return AE_OK;
362 
363 	acpi_processor_set_pdc(handle);
364 	return AE_OK;
365 }
366 
367 void __init acpi_early_processor_set_pdc(void)
368 {
369 	/*
370 	 * Check whether the system is DMI table. If yes, OSPM
371 	 * should not use mwait for CPU-states.
372 	 */
373 	dmi_check_system(processor_idle_dmi_table);
374 
375 	acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
376 			    ACPI_UINT32_MAX,
377 			    early_init_pdc, NULL, NULL, NULL);
378 	acpi_get_devices("ACPI0007", early_init_pdc, NULL, NULL);
379 }
380