SAFE public projects git trees. - safe/jmp/linux-2.6/blob - drivers/acpi/processor_pdc.c

   1 #include <linux/dmi.h>
   2
   3 #include <acpi/acpi_drivers.h>
   4 #include <acpi/processor.h>
   5
   6 #include "internal.h"
   7
   8 #define PREFIX                  "ACPI: "
   9 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  10 ACPI_MODULE_NAME("processor_pdc");
  11
  12 static int set_no_mwait(const struct dmi_system_id *id)
  13 {
  14         printk(KERN_NOTICE PREFIX "%s detected - "
  15                 "disabling mwait for CPU C-states\n", id->ident);
  16         idle_nomwait = 1;
  17         return 0;
  18 }
  19
  20 static struct dmi_system_id __cpuinitdata processor_idle_dmi_table[] = {
  21         {
  22         set_no_mwait, "IFL91 board", {
  23         DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
  24         DMI_MATCH(DMI_SYS_VENDOR, "ZEPTO"),
  25         DMI_MATCH(DMI_PRODUCT_VERSION, "3215W"),
  26         DMI_MATCH(DMI_BOARD_NAME, "IFL91") }, NULL},
  27         {
  28         set_no_mwait, "Extensa 5220", {
  29         DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
  30         DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
  31         DMI_MATCH(DMI_PRODUCT_VERSION, "0100"),
  32         DMI_MATCH(DMI_BOARD_NAME, "Columbia") }, NULL},
  33         {},
  34 };
  35
  36 /*
  37  * _PDC is required for a BIOS-OS handshake for most of the newer
  38  * ACPI processor features.
  39  */
  40 static int acpi_processor_eval_pdc(struct acpi_processor *pr)
  41 {
  42         struct acpi_object_list *pdc_in = pr->pdc;
  43         acpi_status status = AE_OK;
  44
  45         if (!pdc_in)
  46                 return status;
  47         if (idle_nomwait) {
  48                 /*
  49                  * If mwait is disabled for CPU C-states, the C2C3_FFH access
  50                  * mode will be disabled in the parameter of _PDC object.
  51                  * Of course C1_FFH access mode will also be disabled.
  52                  */
  53                 union acpi_object *obj;
  54                 u32 *buffer = NULL;
  55
  56                 obj = pdc_in->pointer;
  57                 buffer = (u32 *)(obj->buffer.pointer);
  58                 buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH);
  59
  60         }
  61         status = acpi_evaluate_object(pr->handle, "_PDC", pdc_in, NULL);
  62
  63         if (ACPI_FAILURE(status))
  64                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
  65                     "Could not evaluate _PDC, using legacy perf. control.\n"));
  66
  67         return status;
  68 }
  69
  70 void acpi_processor_set_pdc(struct acpi_processor *pr)
  71 {
  72         arch_acpi_processor_init_pdc(pr);
  73         acpi_processor_eval_pdc(pr);
  74         arch_acpi_processor_cleanup_pdc(pr);
  75 }
  76 EXPORT_SYMBOL_GPL(acpi_processor_set_pdc);
  77
  78 static acpi_status
  79 early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
  80 {
  81         struct acpi_processor pr;
  82
  83         pr.handle = handle;
  84
  85         /* x86 implementation looks at pr.id to determine some
  86          * CPU capabilites. We can just hard code to 0 since we're
  87          * assuming the CPUs in the system are homogenous and all
  88          * have the same capabilities.
  89          */
  90         pr.id = 0;
  91
  92         acpi_processor_set_pdc(&pr);
  93
  94         return AE_OK;
  95 }
  96
  97 void acpi_early_processor_set_pdc(void)
  98 {
  99         /*
 100          * Check whether the system is DMI table. If yes, OSPM
 101          * should not use mwait for CPU-states.
 102          */
 103         dmi_check_system(processor_idle_dmi_table);
 104
 105         acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 106                             ACPI_UINT32_MAX,
 107                             early_init_pdc, NULL, NULL, NULL);
 108 }