arch/x86/kernel/acpi/processor.c

   1 /*
   2  * Copyright (C) 2005 Intel Corporation
   3  *      Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
   4  *      - Added _PDC for platforms with Intel CPUs
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/module.h>
   9 #include <linux/init.h>
  10 #include <linux/acpi.h>
  11
  12 #include <acpi/processor.h>
  13 #include <asm/acpi.h>
  14
  15 static void init_intel_pdc(struct acpi_processor *pr, struct cpuinfo_x86 *c)
  16 {
  17         struct acpi_object_list *obj_list;
  18         union acpi_object *obj;
  19         u32 *buf;
  20
  21         /* allocate and initialize pdc. It will be used later. */
  22         obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL);
  23         if (!obj_list) {
  24                 printk(KERN_ERR "Memory allocation error\n");
  25                 return;
  26         }
  27
  28         obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
  29         if (!obj) {
  30                 printk(KERN_ERR "Memory allocation error\n");
  31                 kfree(obj_list);
  32                 return;
  33         }
  34
  35         buf = kmalloc(12, GFP_KERNEL);
  36         if (!buf) {
  37                 printk(KERN_ERR "Memory allocation error\n");
  38                 kfree(obj);
  39                 kfree(obj_list);
  40                 return;
  41         }
  42
  43         buf[0] = ACPI_PDC_REVISION_ID;
  44         buf[1] = 1;
  45         buf[2] = ACPI_PDC_C_CAPABILITY_SMP;
  46
  47         /*
  48          * The default of PDC_SMP_T_SWCOORD bit is set for intel x86 cpu so
  49          * that OSPM is capable of native ACPI throttling software
  50          * coordination using BIOS supplied _TSD info.
  51          */
  52         buf[2] |= ACPI_PDC_SMP_T_SWCOORD;
  53         if (cpu_has(c, X86_FEATURE_EST))
  54                 buf[2] |= ACPI_PDC_EST_CAPABILITY_SWSMP;
  55
  56         if (cpu_has(c, X86_FEATURE_ACPI))
  57                 buf[2] |= ACPI_PDC_T_FFH;
  58
  59         /*
  60          * If mwait/monitor is unsupported, C2/C3_FFH will be disabled
  61          */
  62         if (!cpu_has(c, X86_FEATURE_MWAIT))
  63                 buf[2] &= ~(ACPI_PDC_C_C2C3_FFH);
  64
  65         obj->type = ACPI_TYPE_BUFFER;
  66         obj->buffer.length = 12;
  67         obj->buffer.pointer = (u8 *) buf;
  68         obj_list->count = 1;
  69         obj_list->pointer = obj;
  70         pr->pdc = obj_list;
  71
  72         return;
  73 }
  74
  75
  76 /* Initialize _PDC data based on the CPU vendor */
  77 void arch_acpi_processor_init_pdc(struct acpi_processor *pr)
  78 {
  79         struct cpuinfo_x86 *c = &cpu_data(pr->id);
  80
  81         pr->pdc = NULL;
  82         if (c->x86_vendor == X86_VENDOR_INTEL)
  83                 init_intel_pdc(pr, c);
  84
  85         return;
  86 }
  87
  88 EXPORT_SYMBOL(arch_acpi_processor_init_pdc);
  89
  90 void arch_acpi_processor_cleanup_pdc(struct acpi_processor *pr)
  91 {
  92         if (pr->pdc) {
  93                 kfree(pr->pdc->pointer->buffer.pointer);
  94                 kfree(pr->pdc->pointer);
  95                 kfree(pr->pdc);
  96                 pr->pdc = NULL;
  97         }
  98 }
  99
 100 EXPORT_SYMBOL(arch_acpi_processor_cleanup_pdc);