processor_core.c revision d18960494f65ca4fa0d67c865aaca99452070d15 
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/dmi.h>
11#include <linux/slab.h>
12
13#include <acpi/acpi_drivers.h>
14#include <acpi/processor.h>
15
16#include "internal.h"
17
18#define PREFIX			"ACPI: "
19#define _COMPONENT		ACPI_PROCESSOR_COMPONENT
20ACPI_MODULE_NAME("processor_core");
21
22static int set_no_mwait(const struct dmi_system_id *id)
23{
24	printk(KERN_NOTICE PREFIX "%s detected - "
25		"disabling mwait for CPU C-states\n", id->ident);
26	boot_option_idle_override = IDLE_NOMWAIT;
27	return 0;
28}
29
30static struct dmi_system_id __cpuinitdata processor_idle_dmi_table[] = {
31	{
32	set_no_mwait, "Extensa 5220", {
33	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
34	DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
35	DMI_MATCH(DMI_PRODUCT_VERSION, "0100"),
36	DMI_MATCH(DMI_BOARD_NAME, "Columbia") }, NULL},
37	{},
38};
39
40#ifdef CONFIG_SMP
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	if (buffer.pointer)
162		kfree(buffer.pointer);
163	return apic_id;
164}
165
166int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
167{
168	int i;
169	int apic_id = -1;
170
171	apic_id = map_mat_entry(handle, type, acpi_id);
172	if (apic_id == -1)
173		apic_id = map_madt_entry(type, acpi_id);
174	if (apic_id == -1)
175		return apic_id;
176
177	for_each_possible_cpu(i) {
178		if (cpu_physical_id(i) == apic_id)
179			return i;
180	}
181	return -1;
182}
183EXPORT_SYMBOL_GPL(acpi_get_cpuid);
184#endif
185
186static bool processor_physically_present(acpi_handle handle)
187{
188	int cpuid, type;
189	u32 acpi_id;
190	acpi_status status;
191	acpi_object_type acpi_type;
192	unsigned long long tmp;
193	union acpi_object object = { 0 };
194	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
195
196	status = acpi_get_type(handle, &acpi_type);
197	if (ACPI_FAILURE(status))
198		return false;
199
200	switch (acpi_type) {
201	case ACPI_TYPE_PROCESSOR:
202		status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
203		if (ACPI_FAILURE(status))
204			return false;
205		acpi_id = object.processor.proc_id;
206		break;
207	case ACPI_TYPE_DEVICE:
208		status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
209		if (ACPI_FAILURE(status))
210			return false;
211		acpi_id = tmp;
212		break;
213	default:
214		return false;
215	}
216
217	type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
218	cpuid = acpi_get_cpuid(handle, type, acpi_id);
219
220	if ((cpuid == -1) && (num_possible_cpus() > 1))
221		return false;
222
223	return true;
224}
225
226static void acpi_set_pdc_bits(u32 *buf)
227{
228	buf[0] = ACPI_PDC_REVISION_ID;
229	buf[1] = 1;
230
231	/* Enable coordination with firmware's _TSD info */
232	buf[2] = ACPI_PDC_SMP_T_SWCOORD;
233
234	/* Twiddle arch-specific bits needed for _PDC */
235	arch_acpi_set_pdc_bits(buf);
236}
237
238static struct acpi_object_list *acpi_processor_alloc_pdc(void)
239{
240	struct acpi_object_list *obj_list;
241	union acpi_object *obj;
242	u32 *buf;
243
244	/* allocate and initialize pdc. It will be used later. */
245	obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL);
246	if (!obj_list) {
247		printk(KERN_ERR "Memory allocation error\n");
248		return NULL;
249	}
250
251	obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
252	if (!obj) {
253		printk(KERN_ERR "Memory allocation error\n");
254		kfree(obj_list);
255		return NULL;
256	}
257
258	buf = kmalloc(12, GFP_KERNEL);
259	if (!buf) {
260		printk(KERN_ERR "Memory allocation error\n");
261		kfree(obj);
262		kfree(obj_list);
263		return NULL;
264	}
265
266	acpi_set_pdc_bits(buf);
267
268	obj->type = ACPI_TYPE_BUFFER;
269	obj->buffer.length = 12;
270	obj->buffer.pointer = (u8 *) buf;
271	obj_list->count = 1;
272	obj_list->pointer = obj;
273
274	return obj_list;
275}
276
277/*
278 * _PDC is required for a BIOS-OS handshake for most of the newer
279 * ACPI processor features.
280 */
281static int
282acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
283{
284	acpi_status status = AE_OK;
285
286	if (boot_option_idle_override == IDLE_NOMWAIT) {
287		/*
288		 * If mwait is disabled for CPU C-states, the C2C3_FFH access
289		 * mode will be disabled in the parameter of _PDC object.
290		 * Of course C1_FFH access mode will also be disabled.
291		 */
292		union acpi_object *obj;
293		u32 *buffer = NULL;
294
295		obj = pdc_in->pointer;
296		buffer = (u32 *)(obj->buffer.pointer);
297		buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH);
298
299	}
300	status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL);
301
302	if (ACPI_FAILURE(status))
303		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
304		    "Could not evaluate _PDC, using legacy perf. control.\n"));
305
306	return status;
307}
308
309void acpi_processor_set_pdc(acpi_handle handle)
310{
311	struct acpi_object_list *obj_list;
312
313	if (arch_has_acpi_pdc() == false)
314		return;
315
316	obj_list = acpi_processor_alloc_pdc();
317	if (!obj_list)
318		return;
319
320	acpi_processor_eval_pdc(handle, obj_list);
321
322	kfree(obj_list->pointer->buffer.pointer);
323	kfree(obj_list->pointer);
324	kfree(obj_list);
325}
326EXPORT_SYMBOL_GPL(acpi_processor_set_pdc);
327
328static acpi_status
329early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
330{
331	if (processor_physically_present(handle) == false)
332		return AE_OK;
333
334	acpi_processor_set_pdc(handle);
335	return AE_OK;
336}
337
338void __init acpi_early_processor_set_pdc(void)
339{
340	/*
341	 * Check whether the system is DMI table. If yes, OSPM
342	 * should not use mwait for CPU-states.
343	 */
344	dmi_check_system(processor_idle_dmi_table);
345
346	acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
347			    ACPI_UINT32_MAX,
348			    early_init_pdc, NULL, NULL, NULL);
349	acpi_get_devices("ACPI0007", early_init_pdc, NULL, NULL);
350}
351