xref: /linux/drivers/acpi/processor_core.c (revision cc4589ebfae6f8dbb5cf880a0a67eedab3416492)
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
20 ACPI_MODULE_NAME("processor_core");
21 
22 static 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 	idle_nomwait = 1;
27 	return 0;
28 }
29 
30 static struct dmi_system_id __cpuinitdata processor_idle_dmi_table[] = {
31 	{
32 	set_no_mwait, "IFL91 board", {
33 	DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
34 	DMI_MATCH(DMI_SYS_VENDOR, "ZEPTO"),
35 	DMI_MATCH(DMI_PRODUCT_VERSION, "3215W"),
36 	DMI_MATCH(DMI_BOARD_NAME, "IFL91") }, NULL},
37 	{
38 	set_no_mwait, "Extensa 5220", {
39 	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
40 	DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
41 	DMI_MATCH(DMI_PRODUCT_VERSION, "0100"),
42 	DMI_MATCH(DMI_BOARD_NAME, "Columbia") }, NULL},
43 	{},
44 };
45 
46 #ifdef CONFIG_SMP
47 static int map_lapic_id(struct acpi_subtable_header *entry,
48 		 u32 acpi_id, int *apic_id)
49 {
50 	struct acpi_madt_local_apic *lapic =
51 		(struct acpi_madt_local_apic *)entry;
52 
53 	if (!(lapic->lapic_flags & ACPI_MADT_ENABLED))
54 		return 0;
55 
56 	if (lapic->processor_id != acpi_id)
57 		return 0;
58 
59 	*apic_id = lapic->id;
60 	return 1;
61 }
62 
63 static int map_x2apic_id(struct acpi_subtable_header *entry,
64 			 int device_declaration, u32 acpi_id, int *apic_id)
65 {
66 	struct acpi_madt_local_x2apic *apic =
67 		(struct acpi_madt_local_x2apic *)entry;
68 
69 	if (!(apic->lapic_flags & ACPI_MADT_ENABLED))
70 		return 0;
71 
72 	if (device_declaration && (apic->uid == acpi_id)) {
73 		*apic_id = apic->local_apic_id;
74 		return 1;
75 	}
76 
77 	return 0;
78 }
79 
80 static int map_lsapic_id(struct acpi_subtable_header *entry,
81 		int device_declaration, u32 acpi_id, int *apic_id)
82 {
83 	struct acpi_madt_local_sapic *lsapic =
84 		(struct acpi_madt_local_sapic *)entry;
85 
86 	if (!(lsapic->lapic_flags & ACPI_MADT_ENABLED))
87 		return 0;
88 
89 	if (device_declaration) {
90 		if ((entry->length < 16) || (lsapic->uid != acpi_id))
91 			return 0;
92 	} else if (lsapic->processor_id != acpi_id)
93 		return 0;
94 
95 	*apic_id = (lsapic->id << 8) | lsapic->eid;
96 	return 1;
97 }
98 
99 static int map_madt_entry(int type, u32 acpi_id)
100 {
101 	unsigned long madt_end, entry;
102 	static struct acpi_table_madt *madt;
103 	static int read_madt;
104 	int apic_id = -1;
105 
106 	if (!read_madt) {
107 		if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0,
108 					(struct acpi_table_header **)&madt)))
109 			madt = NULL;
110 		read_madt++;
111 	}
112 
113 	if (!madt)
114 		return apic_id;
115 
116 	entry = (unsigned long)madt;
117 	madt_end = entry + madt->header.length;
118 
119 	/* Parse all entries looking for a match. */
120 
121 	entry += sizeof(struct acpi_table_madt);
122 	while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
123 		struct acpi_subtable_header *header =
124 			(struct acpi_subtable_header *)entry;
125 		if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
126 			if (map_lapic_id(header, acpi_id, &apic_id))
127 				break;
128 		} else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC) {
129 			if (map_x2apic_id(header, type, acpi_id, &apic_id))
130 				break;
131 		} else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
132 			if (map_lsapic_id(header, type, acpi_id, &apic_id))
133 				break;
134 		}
135 		entry += header->length;
136 	}
137 	return apic_id;
138 }
139 
140 static int map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
141 {
142 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
143 	union acpi_object *obj;
144 	struct acpi_subtable_header *header;
145 	int apic_id = -1;
146 
147 	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
148 		goto exit;
149 
150 	if (!buffer.length || !buffer.pointer)
151 		goto exit;
152 
153 	obj = buffer.pointer;
154 	if (obj->type != ACPI_TYPE_BUFFER ||
155 	    obj->buffer.length < sizeof(struct acpi_subtable_header)) {
156 		goto exit;
157 	}
158 
159 	header = (struct acpi_subtable_header *)obj->buffer.pointer;
160 	if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
161 		map_lapic_id(header, acpi_id, &apic_id);
162 	} else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
163 		map_lsapic_id(header, type, acpi_id, &apic_id);
164 	}
165 
166 exit:
167 	if (buffer.pointer)
168 		kfree(buffer.pointer);
169 	return apic_id;
170 }
171 
172 int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
173 {
174 	int i;
175 	int apic_id = -1;
176 
177 	apic_id = map_mat_entry(handle, type, acpi_id);
178 	if (apic_id == -1)
179 		apic_id = map_madt_entry(type, acpi_id);
180 	if (apic_id == -1)
181 		return apic_id;
182 
183 	for_each_possible_cpu(i) {
184 		if (cpu_physical_id(i) == apic_id)
185 			return i;
186 	}
187 	return -1;
188 }
189 EXPORT_SYMBOL_GPL(acpi_get_cpuid);
190 #endif
191 
192 static bool processor_physically_present(acpi_handle handle)
193 {
194 	int cpuid, type;
195 	u32 acpi_id;
196 	acpi_status status;
197 	acpi_object_type acpi_type;
198 	unsigned long long tmp;
199 	union acpi_object object = { 0 };
200 	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
201 
202 	status = acpi_get_type(handle, &acpi_type);
203 	if (ACPI_FAILURE(status))
204 		return false;
205 
206 	switch (acpi_type) {
207 	case ACPI_TYPE_PROCESSOR:
208 		status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
209 		if (ACPI_FAILURE(status))
210 			return false;
211 		acpi_id = object.processor.proc_id;
212 		break;
213 	case ACPI_TYPE_DEVICE:
214 		status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
215 		if (ACPI_FAILURE(status))
216 			return false;
217 		acpi_id = tmp;
218 		break;
219 	default:
220 		return false;
221 	}
222 
223 	type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
224 	cpuid = acpi_get_cpuid(handle, type, acpi_id);
225 
226 	if ((cpuid == -1) && (num_possible_cpus() > 1))
227 		return false;
228 
229 	return true;
230 }
231 
232 static void acpi_set_pdc_bits(u32 *buf)
233 {
234 	buf[0] = ACPI_PDC_REVISION_ID;
235 	buf[1] = 1;
236 
237 	/* Enable coordination with firmware's _TSD info */
238 	buf[2] = ACPI_PDC_SMP_T_SWCOORD;
239 
240 	/* Twiddle arch-specific bits needed for _PDC */
241 	arch_acpi_set_pdc_bits(buf);
242 }
243 
244 static struct acpi_object_list *acpi_processor_alloc_pdc(void)
245 {
246 	struct acpi_object_list *obj_list;
247 	union acpi_object *obj;
248 	u32 *buf;
249 
250 	/* allocate and initialize pdc. It will be used later. */
251 	obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL);
252 	if (!obj_list) {
253 		printk(KERN_ERR "Memory allocation error\n");
254 		return NULL;
255 	}
256 
257 	obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
258 	if (!obj) {
259 		printk(KERN_ERR "Memory allocation error\n");
260 		kfree(obj_list);
261 		return NULL;
262 	}
263 
264 	buf = kmalloc(12, GFP_KERNEL);
265 	if (!buf) {
266 		printk(KERN_ERR "Memory allocation error\n");
267 		kfree(obj);
268 		kfree(obj_list);
269 		return NULL;
270 	}
271 
272 	acpi_set_pdc_bits(buf);
273 
274 	obj->type = ACPI_TYPE_BUFFER;
275 	obj->buffer.length = 12;
276 	obj->buffer.pointer = (u8 *) buf;
277 	obj_list->count = 1;
278 	obj_list->pointer = obj;
279 
280 	return obj_list;
281 }
282 
283 /*
284  * _PDC is required for a BIOS-OS handshake for most of the newer
285  * ACPI processor features.
286  */
287 static int
288 acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
289 {
290 	acpi_status status = AE_OK;
291 
292 	if (idle_nomwait) {
293 		/*
294 		 * If mwait is disabled for CPU C-states, the C2C3_FFH access
295 		 * mode will be disabled in the parameter of _PDC object.
296 		 * Of course C1_FFH access mode will also be disabled.
297 		 */
298 		union acpi_object *obj;
299 		u32 *buffer = NULL;
300 
301 		obj = pdc_in->pointer;
302 		buffer = (u32 *)(obj->buffer.pointer);
303 		buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH);
304 
305 	}
306 	status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL);
307 
308 	if (ACPI_FAILURE(status))
309 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
310 		    "Could not evaluate _PDC, using legacy perf. control.\n"));
311 
312 	return status;
313 }
314 
315 void acpi_processor_set_pdc(acpi_handle handle)
316 {
317 	struct acpi_object_list *obj_list;
318 
319 	if (arch_has_acpi_pdc() == false)
320 		return;
321 
322 	obj_list = acpi_processor_alloc_pdc();
323 	if (!obj_list)
324 		return;
325 
326 	acpi_processor_eval_pdc(handle, obj_list);
327 
328 	kfree(obj_list->pointer->buffer.pointer);
329 	kfree(obj_list->pointer);
330 	kfree(obj_list);
331 }
332 EXPORT_SYMBOL_GPL(acpi_processor_set_pdc);
333 
334 static acpi_status
335 early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
336 {
337 	if (processor_physically_present(handle) == false)
338 		return AE_OK;
339 
340 	acpi_processor_set_pdc(handle);
341 	return AE_OK;
342 }
343 
344 void __init acpi_early_processor_set_pdc(void)
345 {
346 	/*
347 	 * Check whether the system is DMI table. If yes, OSPM
348 	 * should not use mwait for CPU-states.
349 	 */
350 	dmi_check_system(processor_idle_dmi_table);
351 
352 	acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
353 			    ACPI_UINT32_MAX,
354 			    early_init_pdc, NULL, NULL, NULL);
355 }
356