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Linux/drivers/acpi/processor_core.c

  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 _COMPONENT              ACPI_PROCESSOR_COMPONENT
 19 ACPI_MODULE_NAME("processor_core");
 20 
 21 static int map_lapic_id(struct acpi_subtable_header *entry,
 22                  u32 acpi_id, int *apic_id)
 23 {
 24         struct acpi_madt_local_apic *lapic =
 25                 (struct acpi_madt_local_apic *)entry;
 26 
 27         if (!(lapic->lapic_flags & ACPI_MADT_ENABLED))
 28                 return -ENODEV;
 29 
 30         if (lapic->processor_id != acpi_id)
 31                 return -EINVAL;
 32 
 33         *apic_id = lapic->id;
 34         return 0;
 35 }
 36 
 37 static int map_x2apic_id(struct acpi_subtable_header *entry,
 38                          int device_declaration, u32 acpi_id, int *apic_id)
 39 {
 40         struct acpi_madt_local_x2apic *apic =
 41                 (struct acpi_madt_local_x2apic *)entry;
 42 
 43         if (!(apic->lapic_flags & ACPI_MADT_ENABLED))
 44                 return -ENODEV;
 45 
 46         if (device_declaration && (apic->uid == acpi_id)) {
 47                 *apic_id = apic->local_apic_id;
 48                 return 0;
 49         }
 50 
 51         return -EINVAL;
 52 }
 53 
 54 static int map_lsapic_id(struct acpi_subtable_header *entry,
 55                 int device_declaration, u32 acpi_id, int *apic_id)
 56 {
 57         struct acpi_madt_local_sapic *lsapic =
 58                 (struct acpi_madt_local_sapic *)entry;
 59 
 60         if (!(lsapic->lapic_flags & ACPI_MADT_ENABLED))
 61                 return -ENODEV;
 62 
 63         if (device_declaration) {
 64                 if ((entry->length < 16) || (lsapic->uid != acpi_id))
 65                         return -EINVAL;
 66         } else if (lsapic->processor_id != acpi_id)
 67                 return -EINVAL;
 68 
 69         *apic_id = (lsapic->id << 8) | lsapic->eid;
 70         return 0;
 71 }
 72 
 73 static int map_madt_entry(int type, u32 acpi_id)
 74 {
 75         unsigned long madt_end, entry;
 76         static struct acpi_table_madt *madt;
 77         static int read_madt;
 78         int apic_id = -1;
 79 
 80         if (!read_madt) {
 81                 if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0,
 82                                         (struct acpi_table_header **)&madt)))
 83                         madt = NULL;
 84                 read_madt++;
 85         }
 86 
 87         if (!madt)
 88                 return apic_id;
 89 
 90         entry = (unsigned long)madt;
 91         madt_end = entry + madt->header.length;
 92 
 93         /* Parse all entries looking for a match. */
 94 
 95         entry += sizeof(struct acpi_table_madt);
 96         while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
 97                 struct acpi_subtable_header *header =
 98                         (struct acpi_subtable_header *)entry;
 99                 if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
100                         if (!map_lapic_id(header, acpi_id, &apic_id))
101                                 break;
102                 } else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC) {
103                         if (!map_x2apic_id(header, type, acpi_id, &apic_id))
104                                 break;
105                 } else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
106                         if (!map_lsapic_id(header, type, acpi_id, &apic_id))
107                                 break;
108                 }
109                 entry += header->length;
110         }
111         return apic_id;
112 }
113 
114 static int map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
115 {
116         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
117         union acpi_object *obj;
118         struct acpi_subtable_header *header;
119         int apic_id = -1;
120 
121         if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
122                 goto exit;
123 
124         if (!buffer.length || !buffer.pointer)
125                 goto exit;
126 
127         obj = buffer.pointer;
128         if (obj->type != ACPI_TYPE_BUFFER ||
129             obj->buffer.length < sizeof(struct acpi_subtable_header)) {
130                 goto exit;
131         }
132 
133         header = (struct acpi_subtable_header *)obj->buffer.pointer;
134         if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
135                 map_lapic_id(header, acpi_id, &apic_id);
136         } else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
137                 map_lsapic_id(header, type, acpi_id, &apic_id);
138         }
139 
140 exit:
141         kfree(buffer.pointer);
142         return apic_id;
143 }
144 
145 int acpi_get_apicid(acpi_handle handle, int type, u32 acpi_id)
146 {
147         int apic_id;
148 
149         apic_id = map_mat_entry(handle, type, acpi_id);
150         if (apic_id == -1)
151                 apic_id = map_madt_entry(type, acpi_id);
152 
153         return apic_id;
154 }
155 
156 int acpi_map_cpuid(int apic_id, u32 acpi_id)
157 {
158 #ifdef CONFIG_SMP
159         int i;
160 #endif
161 
162         if (apic_id == -1) {
163                 /*
164                  * On UP processor, there is no _MAT or MADT table.
165                  * So above apic_id is always set to -1.
166                  *
167                  * BIOS may define multiple CPU handles even for UP processor.
168                  * For example,
169                  *
170                  * Scope (_PR)
171                  * {
172                  *     Processor (CPU0, 0x00, 0x00000410, 0x06) {}
173                  *     Processor (CPU1, 0x01, 0x00000410, 0x06) {}
174                  *     Processor (CPU2, 0x02, 0x00000410, 0x06) {}
175                  *     Processor (CPU3, 0x03, 0x00000410, 0x06) {}
176                  * }
177                  *
178                  * Ignores apic_id and always returns 0 for the processor
179                  * handle with acpi id 0 if nr_cpu_ids is 1.
180                  * This should be the case if SMP tables are not found.
181                  * Return -1 for other CPU's handle.
182                  */
183                 if (nr_cpu_ids <= 1 && acpi_id == 0)
184                         return acpi_id;
185                 else
186                         return apic_id;
187         }
188 
189 #ifdef CONFIG_SMP
190         for_each_possible_cpu(i) {
191                 if (cpu_physical_id(i) == apic_id)
192                         return i;
193         }
194 #else
195         /* In UP kernel, only processor 0 is valid */
196         if (apic_id == 0)
197                 return apic_id;
198 #endif
199         return -1;
200 }
201 
202 int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
203 {
204         int apic_id;
205 
206         apic_id = acpi_get_apicid(handle, type, acpi_id);
207 
208         return acpi_map_cpuid(apic_id, acpi_id);
209 }
210 EXPORT_SYMBOL_GPL(acpi_get_cpuid);
211 
212 static bool __init processor_physically_present(acpi_handle handle)
213 {
214         int cpuid, type;
215         u32 acpi_id;
216         acpi_status status;
217         acpi_object_type acpi_type;
218         unsigned long long tmp;
219         union acpi_object object = { 0 };
220         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
221 
222         status = acpi_get_type(handle, &acpi_type);
223         if (ACPI_FAILURE(status))
224                 return false;
225 
226         switch (acpi_type) {
227         case ACPI_TYPE_PROCESSOR:
228                 status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
229                 if (ACPI_FAILURE(status))
230                         return false;
231                 acpi_id = object.processor.proc_id;
232                 break;
233         case ACPI_TYPE_DEVICE:
234                 status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
235                 if (ACPI_FAILURE(status))
236                         return false;
237                 acpi_id = tmp;
238                 break;
239         default:
240                 return false;
241         }
242 
243         type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
244         cpuid = acpi_get_cpuid(handle, type, acpi_id);
245 
246         if (cpuid == -1)
247                 return false;
248 
249         return true;
250 }
251 
252 static void acpi_set_pdc_bits(u32 *buf)
253 {
254         buf[0] = ACPI_PDC_REVISION_ID;
255         buf[1] = 1;
256 
257         /* Enable coordination with firmware's _TSD info */
258         buf[2] = ACPI_PDC_SMP_T_SWCOORD;
259 
260         /* Twiddle arch-specific bits needed for _PDC */
261         arch_acpi_set_pdc_bits(buf);
262 }
263 
264 static struct acpi_object_list *acpi_processor_alloc_pdc(void)
265 {
266         struct acpi_object_list *obj_list;
267         union acpi_object *obj;
268         u32 *buf;
269 
270         /* allocate and initialize pdc. It will be used later. */
271         obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL);
272         if (!obj_list) {
273                 printk(KERN_ERR "Memory allocation error\n");
274                 return NULL;
275         }
276 
277         obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
278         if (!obj) {
279                 printk(KERN_ERR "Memory allocation error\n");
280                 kfree(obj_list);
281                 return NULL;
282         }
283 
284         buf = kmalloc(12, GFP_KERNEL);
285         if (!buf) {
286                 printk(KERN_ERR "Memory allocation error\n");
287                 kfree(obj);
288                 kfree(obj_list);
289                 return NULL;
290         }
291 
292         acpi_set_pdc_bits(buf);
293 
294         obj->type = ACPI_TYPE_BUFFER;
295         obj->buffer.length = 12;
296         obj->buffer.pointer = (u8 *) buf;
297         obj_list->count = 1;
298         obj_list->pointer = obj;
299 
300         return obj_list;
301 }
302 
303 /*
304  * _PDC is required for a BIOS-OS handshake for most of the newer
305  * ACPI processor features.
306  */
307 static acpi_status
308 acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
309 {
310         acpi_status status = AE_OK;
311 
312         if (boot_option_idle_override == IDLE_NOMWAIT) {
313                 /*
314                  * If mwait is disabled for CPU C-states, the C2C3_FFH access
315                  * mode will be disabled in the parameter of _PDC object.
316                  * Of course C1_FFH access mode will also be disabled.
317                  */
318                 union acpi_object *obj;
319                 u32 *buffer = NULL;
320 
321                 obj = pdc_in->pointer;
322                 buffer = (u32 *)(obj->buffer.pointer);
323                 buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH);
324 
325         }
326         status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL);
327 
328         if (ACPI_FAILURE(status))
329                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
330                     "Could not evaluate _PDC, using legacy perf. control.\n"));
331 
332         return status;
333 }
334 
335 void acpi_processor_set_pdc(acpi_handle handle)
336 {
337         struct acpi_object_list *obj_list;
338 
339         if (arch_has_acpi_pdc() == false)
340                 return;
341 
342         obj_list = acpi_processor_alloc_pdc();
343         if (!obj_list)
344                 return;
345 
346         acpi_processor_eval_pdc(handle, obj_list);
347 
348         kfree(obj_list->pointer->buffer.pointer);
349         kfree(obj_list->pointer);
350         kfree(obj_list);
351 }
352 
353 static acpi_status __init
354 early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
355 {
356         if (processor_physically_present(handle) == false)
357                 return AE_OK;
358 
359         acpi_processor_set_pdc(handle);
360         return AE_OK;
361 }
362 
363 #if defined(CONFIG_X86) || defined(CONFIG_IA64)
364 static int __init set_no_mwait(const struct dmi_system_id *id)
365 {
366         pr_notice(PREFIX "%s detected - disabling mwait for CPU C-states\n",
367                   id->ident);
368         boot_option_idle_override = IDLE_NOMWAIT;
369         return 0;
370 }
371 
372 static struct dmi_system_id processor_idle_dmi_table[] __initdata = {
373         {
374         set_no_mwait, "Extensa 5220", {
375         DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
376         DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
377         DMI_MATCH(DMI_PRODUCT_VERSION, "0100"),
378         DMI_MATCH(DMI_BOARD_NAME, "Columbia") }, NULL},
379         {},
380 };
381 
382 static void __init processor_dmi_check(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 #else
391 static inline void processor_dmi_check(void) {}
392 #endif
393 
394 void __init acpi_early_processor_set_pdc(void)
395 {
396         processor_dmi_check();
397 
398         acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
399                             ACPI_UINT32_MAX,
400                             early_init_pdc, NULL, NULL, NULL);
401         acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, early_init_pdc, NULL, NULL);
402 }
403 

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