processor_core.c revision 8b48463f89429af408ff695244dc627e1acff4f7 
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#include <linux/acpi.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 __init 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 processor_idle_dmi_table[] __initdata = {
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
40static int map_lapic_id(struct acpi_subtable_header *entry,
41		 u32 acpi_id, int *apic_id)
42{
43	struct acpi_madt_local_apic *lapic =
44		(struct acpi_madt_local_apic *)entry;
45
46	if (!(lapic->lapic_flags & ACPI_MADT_ENABLED))
47		return 0;
48
49	if (lapic->processor_id != acpi_id)
50		return 0;
51
52	*apic_id = lapic->id;
53	return 1;
54}
55
56static int map_x2apic_id(struct acpi_subtable_header *entry,
57			 int device_declaration, u32 acpi_id, int *apic_id)
58{
59	struct acpi_madt_local_x2apic *apic =
60		(struct acpi_madt_local_x2apic *)entry;
61
62	if (!(apic->lapic_flags & ACPI_MADT_ENABLED))
63		return 0;
64
65	if (device_declaration && (apic->uid == acpi_id)) {
66		*apic_id = apic->local_apic_id;
67		return 1;
68	}
69
70	return 0;
71}
72
73static int map_lsapic_id(struct acpi_subtable_header *entry,
74		int device_declaration, u32 acpi_id, int *apic_id)
75{
76	struct acpi_madt_local_sapic *lsapic =
77		(struct acpi_madt_local_sapic *)entry;
78
79	if (!(lsapic->lapic_flags & ACPI_MADT_ENABLED))
80		return 0;
81
82	if (device_declaration) {
83		if ((entry->length < 16) || (lsapic->uid != acpi_id))
84			return 0;
85	} else if (lsapic->processor_id != acpi_id)
86		return 0;
87
88	*apic_id = (lsapic->id << 8) | lsapic->eid;
89	return 1;
90}
91
92static int map_madt_entry(int type, u32 acpi_id)
93{
94	unsigned long madt_end, entry;
95	static struct acpi_table_madt *madt;
96	static int read_madt;
97	int apic_id = -1;
98
99	if (!read_madt) {
100		if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0,
101					(struct acpi_table_header **)&madt)))
102			madt = NULL;
103		read_madt++;
104	}
105
106	if (!madt)
107		return apic_id;
108
109	entry = (unsigned long)madt;
110	madt_end = entry + madt->header.length;
111
112	/* Parse all entries looking for a match. */
113
114	entry += sizeof(struct acpi_table_madt);
115	while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
116		struct acpi_subtable_header *header =
117			(struct acpi_subtable_header *)entry;
118		if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
119			if (map_lapic_id(header, acpi_id, &apic_id))
120				break;
121		} else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC) {
122			if (map_x2apic_id(header, type, acpi_id, &apic_id))
123				break;
124		} else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
125			if (map_lsapic_id(header, type, acpi_id, &apic_id))
126				break;
127		}
128		entry += header->length;
129	}
130	return apic_id;
131}
132
133static int map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
134{
135	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
136	union acpi_object *obj;
137	struct acpi_subtable_header *header;
138	int apic_id = -1;
139
140	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
141		goto exit;
142
143	if (!buffer.length || !buffer.pointer)
144		goto exit;
145
146	obj = buffer.pointer;
147	if (obj->type != ACPI_TYPE_BUFFER ||
148	    obj->buffer.length < sizeof(struct acpi_subtable_header)) {
149		goto exit;
150	}
151
152	header = (struct acpi_subtable_header *)obj->buffer.pointer;
153	if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
154		map_lapic_id(header, acpi_id, &apic_id);
155	} else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
156		map_lsapic_id(header, type, acpi_id, &apic_id);
157	}
158
159exit:
160	kfree(buffer.pointer);
161	return apic_id;
162}
163
164int acpi_get_apicid(acpi_handle handle, int type, u32 acpi_id)
165{
166	int apic_id;
167
168	apic_id = map_mat_entry(handle, type, acpi_id);
169	if (apic_id == -1)
170		apic_id = map_madt_entry(type, acpi_id);
171
172	return apic_id;
173}
174
175int acpi_map_cpuid(int apic_id, u32 acpi_id)
176{
177#ifdef CONFIG_SMP
178	int i;
179#endif
180
181	if (apic_id == -1) {
182		/*
183		 * On UP processor, there is no _MAT or MADT table.
184		 * So above apic_id is always set to -1.
185		 *
186		 * BIOS may define multiple CPU handles even for UP processor.
187		 * For example,
188		 *
189		 * Scope (_PR)
190                 * {
191		 *     Processor (CPU0, 0x00, 0x00000410, 0x06) {}
192		 *     Processor (CPU1, 0x01, 0x00000410, 0x06) {}
193		 *     Processor (CPU2, 0x02, 0x00000410, 0x06) {}
194		 *     Processor (CPU3, 0x03, 0x00000410, 0x06) {}
195		 * }
196		 *
197		 * Ignores apic_id and always returns 0 for the processor
198		 * handle with acpi id 0 if nr_cpu_ids is 1.
199		 * This should be the case if SMP tables are not found.
200		 * Return -1 for other CPU's handle.
201		 */
202		if (nr_cpu_ids <= 1 && acpi_id == 0)
203			return acpi_id;
204		else
205			return apic_id;
206	}
207
208#ifdef CONFIG_SMP
209	for_each_possible_cpu(i) {
210		if (cpu_physical_id(i) == apic_id)
211			return i;
212	}
213#else
214	/* In UP kernel, only processor 0 is valid */
215	if (apic_id == 0)
216		return apic_id;
217#endif
218	return -1;
219}
220
221int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
222{
223	int apic_id;
224
225	apic_id = acpi_get_apicid(handle, type, acpi_id);
226
227	return acpi_map_cpuid(apic_id, acpi_id);
228}
229EXPORT_SYMBOL_GPL(acpi_get_cpuid);
230
231static bool __init processor_physically_present(acpi_handle handle)
232{
233	int cpuid, type;
234	u32 acpi_id;
235	acpi_status status;
236	acpi_object_type acpi_type;
237	unsigned long long tmp;
238	union acpi_object object = { 0 };
239	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
240
241	status = acpi_get_type(handle, &acpi_type);
242	if (ACPI_FAILURE(status))
243		return false;
244
245	switch (acpi_type) {
246	case ACPI_TYPE_PROCESSOR:
247		status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
248		if (ACPI_FAILURE(status))
249			return false;
250		acpi_id = object.processor.proc_id;
251		break;
252	case ACPI_TYPE_DEVICE:
253		status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
254		if (ACPI_FAILURE(status))
255			return false;
256		acpi_id = tmp;
257		break;
258	default:
259		return false;
260	}
261
262	type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
263	cpuid = acpi_get_cpuid(handle, type, acpi_id);
264
265	if (cpuid == -1)
266		return false;
267
268	return true;
269}
270
271static void acpi_set_pdc_bits(u32 *buf)
272{
273	buf[0] = ACPI_PDC_REVISION_ID;
274	buf[1] = 1;
275
276	/* Enable coordination with firmware's _TSD info */
277	buf[2] = ACPI_PDC_SMP_T_SWCOORD;
278
279	/* Twiddle arch-specific bits needed for _PDC */
280	arch_acpi_set_pdc_bits(buf);
281}
282
283static struct acpi_object_list *acpi_processor_alloc_pdc(void)
284{
285	struct acpi_object_list *obj_list;
286	union acpi_object *obj;
287	u32 *buf;
288
289	/* allocate and initialize pdc. It will be used later. */
290	obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL);
291	if (!obj_list) {
292		printk(KERN_ERR "Memory allocation error\n");
293		return NULL;
294	}
295
296	obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
297	if (!obj) {
298		printk(KERN_ERR "Memory allocation error\n");
299		kfree(obj_list);
300		return NULL;
301	}
302
303	buf = kmalloc(12, GFP_KERNEL);
304	if (!buf) {
305		printk(KERN_ERR "Memory allocation error\n");
306		kfree(obj);
307		kfree(obj_list);
308		return NULL;
309	}
310
311	acpi_set_pdc_bits(buf);
312
313	obj->type = ACPI_TYPE_BUFFER;
314	obj->buffer.length = 12;
315	obj->buffer.pointer = (u8 *) buf;
316	obj_list->count = 1;
317	obj_list->pointer = obj;
318
319	return obj_list;
320}
321
322/*
323 * _PDC is required for a BIOS-OS handshake for most of the newer
324 * ACPI processor features.
325 */
326static int
327acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
328{
329	acpi_status status = AE_OK;
330
331	if (boot_option_idle_override == IDLE_NOMWAIT) {
332		/*
333		 * If mwait is disabled for CPU C-states, the C2C3_FFH access
334		 * mode will be disabled in the parameter of _PDC object.
335		 * Of course C1_FFH access mode will also be disabled.
336		 */
337		union acpi_object *obj;
338		u32 *buffer = NULL;
339
340		obj = pdc_in->pointer;
341		buffer = (u32 *)(obj->buffer.pointer);
342		buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH);
343
344	}
345	status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL);
346
347	if (ACPI_FAILURE(status))
348		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
349		    "Could not evaluate _PDC, using legacy perf. control.\n"));
350
351	return status;
352}
353
354void acpi_processor_set_pdc(acpi_handle handle)
355{
356	struct acpi_object_list *obj_list;
357
358	if (arch_has_acpi_pdc() == false)
359		return;
360
361	obj_list = acpi_processor_alloc_pdc();
362	if (!obj_list)
363		return;
364
365	acpi_processor_eval_pdc(handle, obj_list);
366
367	kfree(obj_list->pointer->buffer.pointer);
368	kfree(obj_list->pointer);
369	kfree(obj_list);
370}
371
372static acpi_status __init
373early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
374{
375	if (processor_physically_present(handle) == false)
376		return AE_OK;
377
378	acpi_processor_set_pdc(handle);
379	return AE_OK;
380}
381
382void __init acpi_early_processor_set_pdc(void)
383{
384	/*
385	 * Check whether the system is DMI table. If yes, OSPM
386	 * should not use mwait for CPU-states.
387	 */
388	dmi_check_system(processor_idle_dmi_table);
389
390	acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
391			    ACPI_UINT32_MAX,
392			    early_init_pdc, NULL, NULL, NULL);
393	acpi_get_devices("ACPI0007", early_init_pdc, NULL, NULL);
394}
395