xref: /openbmc/linux/drivers/acpi/processor_core.c (revision 565d76cb) 
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 	boot_option_idle_override = IDLE_NOMWAIT;
27 	return 0;
28 }
29 
30 static 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
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 	if (buffer.pointer)
162 		kfree(buffer.pointer);
163 	return apic_id;
164 }
165 
166 int 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 }
183 EXPORT_SYMBOL_GPL(acpi_get_cpuid);
184 #endif
185 
186 static 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 
226 static 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 
238 static 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  */
281 static int
282 acpi_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 
309 void 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 }
326 EXPORT_SYMBOL_GPL(acpi_processor_set_pdc);
327 
328 static acpi_status
329 early_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 
338 void __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