drivers/acpi/processor_pdc.c

   1 /*
   2  * Copyright (C) 2005 Intel Corporation
   3  * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
   4  *
   5  *      Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
   6  *      - Added _PDC for platforms with Intel CPUs
   7  */
   8
   9 #define pr_fmt(fmt) "ACPI: " fmt
  10
  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_pdc");
  20
  21 static bool __init processor_physically_present(acpi_handle handle)
  22 {
  23         int cpuid, type;
  24         u32 acpi_id;
  25         acpi_status status;
  26         acpi_object_type acpi_type;
  27         unsigned long long tmp;
  28         union acpi_object object = { 0 };
  29         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
  30
  31         status = acpi_get_type(handle, &acpi_type);
  32         if (ACPI_FAILURE(status))
  33                 return false;
  34
  35         switch (acpi_type) {
  36         case ACPI_TYPE_PROCESSOR:
  37                 status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
  38                 if (ACPI_FAILURE(status))
  39                         return false;
  40                 acpi_id = object.processor.proc_id;
  41                 break;
  42         case ACPI_TYPE_DEVICE:
  43                 status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
  44                 if (ACPI_FAILURE(status))
  45                         return false;
  46                 acpi_id = tmp;
  47                 break;
  48         default:
  49                 return false;
  50         }
  51
  52         type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
  53         cpuid = acpi_get_cpuid(handle, type, acpi_id);
  54
  55         return !invalid_logical_cpuid(cpuid);
  56 }
  57
  58 static void acpi_set_pdc_bits(u32 *buf)
  59 {
  60         buf[0] = ACPI_PDC_REVISION_ID;
  61         buf[1] = 1;
  62
  63         /* Enable coordination with firmware's _TSD info */
  64         buf[2] = ACPI_PDC_SMP_T_SWCOORD;
  65
  66         /* Twiddle arch-specific bits needed for _PDC */
  67         arch_acpi_set_pdc_bits(buf);
  68 }
  69
  70 static struct acpi_object_list *acpi_processor_alloc_pdc(void)
  71 {
  72         struct acpi_object_list *obj_list;
  73         union acpi_object *obj;
  74         u32 *buf;
  75
  76         /* allocate and initialize pdc. It will be used later. */
  77         obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL);
  78         if (!obj_list)
  79                 goto out;
  80
  81         obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
  82         if (!obj) {
  83                 kfree(obj_list);
  84                 goto out;
  85         }
  86
  87         buf = kmalloc(12, GFP_KERNEL);
  88         if (!buf) {
  89                 kfree(obj);
  90                 kfree(obj_list);
  91                 goto out;
  92         }
  93
  94         acpi_set_pdc_bits(buf);
  95
  96         obj->type = ACPI_TYPE_BUFFER;
  97         obj->buffer.length = 12;
  98         obj->buffer.pointer = (u8 *) buf;
  99         obj_list->count = 1;
 100         obj_list->pointer = obj;
 101
 102         return obj_list;
 103 out:
 104         pr_err("Memory allocation error\n");
 105         return NULL;
 106 }
 107
 108 /*
 109  * _PDC is required for a BIOS-OS handshake for most of the newer
 110  * ACPI processor features.
 111  */
 112 static acpi_status
 113 acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
 114 {
 115         acpi_status status = AE_OK;
 116
 117         if (boot_option_idle_override == IDLE_NOMWAIT) {
 118                 /*
 119                  * If mwait is disabled for CPU C-states, the C2C3_FFH access
 120                  * mode will be disabled in the parameter of _PDC object.
 121                  * Of course C1_FFH access mode will also be disabled.
 122                  */
 123                 union acpi_object *obj;
 124                 u32 *buffer = NULL;
 125
 126                 obj = pdc_in->pointer;
 127                 buffer = (u32 *)(obj->buffer.pointer);
 128                 buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH);
 129
 130         }
 131         status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL);
 132
 133         if (ACPI_FAILURE(status))
 134                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 135                     "Could not evaluate _PDC, using legacy perf. control.\n"));
 136
 137         return status;
 138 }
 139
 140 void acpi_processor_set_pdc(acpi_handle handle)
 141 {
 142         struct acpi_object_list *obj_list;
 143
 144         if (arch_has_acpi_pdc() == false)
 145                 return;
 146
 147         obj_list = acpi_processor_alloc_pdc();
 148         if (!obj_list)
 149                 return;
 150
 151         acpi_processor_eval_pdc(handle, obj_list);
 152
 153         kfree(obj_list->pointer->buffer.pointer);
 154         kfree(obj_list->pointer);
 155         kfree(obj_list);
 156 }
 157
 158 static acpi_status __init
 159 early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
 160 {
 161         if (processor_physically_present(handle) == false)
 162                 return AE_OK;
 163
 164         acpi_processor_set_pdc(handle);
 165         return AE_OK;
 166 }
 167
 168 static int __init set_no_mwait(const struct dmi_system_id *id)
 169 {
 170         pr_notice("%s detected - disabling mwait for CPU C-states\n",
 171                   id->ident);
 172         boot_option_idle_override = IDLE_NOMWAIT;
 173         return 0;
 174 }
 175
 176 static struct dmi_system_id processor_idle_dmi_table[] __initdata = {
 177         {
 178         set_no_mwait, "Extensa 5220", {
 179         DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
 180         DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
 181         DMI_MATCH(DMI_PRODUCT_VERSION, "0100"),
 182         DMI_MATCH(DMI_BOARD_NAME, "Columbia") }, NULL},
 183         {},
 184 };
 185
 186 static void __init processor_dmi_check(void)
 187 {
 188         /*
 189          * Check whether the system is DMI table. If yes, OSPM
 190          * should not use mwait for CPU-states.
 191          */
 192         dmi_check_system(processor_idle_dmi_table);
 193 }
 194
 195 void __init acpi_early_processor_set_pdc(void)
 196 {
 197         processor_dmi_check();
 198
 199         acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 200                             ACPI_UINT32_MAX,
 201                             early_init_pdc, NULL, NULL, NULL);
 202         acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, early_init_pdc, NULL, NULL);
 203 }