processor_core.c revision 8ef9fc78911ef64df98feba8ad12e406e8fa479b 
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 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
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	kfree(buffer.pointer);
162	return apic_id;
163}
164
165int 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}
214EXPORT_SYMBOL_GPL(acpi_get_cpuid);
215
216static 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
256static void __cpuinit 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
268static struct acpi_object_list *__cpuinit 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 */
311static int __cpuinit
312acpi_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
339void __cpuinit 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
357static acpi_status __init
358early_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
367void __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