processor_pdc.c revision 47817254b8637b56730aec26eed2c337d3938bb5
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 12#include <acpi/acpi_drivers.h> 13#include <acpi/processor.h> 14 15#include "internal.h" 16 17#define PREFIX "ACPI: " 18#define _COMPONENT ACPI_PROCESSOR_COMPONENT 19ACPI_MODULE_NAME("processor_pdc"); 20 21static int set_no_mwait(const struct dmi_system_id *id) 22{ 23 printk(KERN_NOTICE PREFIX "%s detected - " 24 "disabling mwait for CPU C-states\n", id->ident); 25 idle_nomwait = 1; 26 return 0; 27} 28 29static struct dmi_system_id __cpuinitdata processor_idle_dmi_table[] = { 30 { 31 set_no_mwait, "IFL91 board", { 32 DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"), 33 DMI_MATCH(DMI_SYS_VENDOR, "ZEPTO"), 34 DMI_MATCH(DMI_PRODUCT_VERSION, "3215W"), 35 DMI_MATCH(DMI_BOARD_NAME, "IFL91") }, NULL}, 36 { 37 set_no_mwait, "Extensa 5220", { 38 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"), 39 DMI_MATCH(DMI_SYS_VENDOR, "Acer"), 40 DMI_MATCH(DMI_PRODUCT_VERSION, "0100"), 41 DMI_MATCH(DMI_BOARD_NAME, "Columbia") }, NULL}, 42 {}, 43}; 44 45static void acpi_set_pdc_bits(u32 *buf) 46{ 47 buf[0] = ACPI_PDC_REVISION_ID; 48 buf[1] = 1; 49 50 /* Enable coordination with firmware's _TSD info */ 51 buf[2] = ACPI_PDC_SMP_T_SWCOORD; 52 53 /* Twiddle arch-specific bits needed for _PDC */ 54 arch_acpi_set_pdc_bits(buf); 55} 56 57static void acpi_processor_init_pdc(struct acpi_processor *pr) 58{ 59 struct acpi_object_list *obj_list; 60 union acpi_object *obj; 61 u32 *buf; 62 63 pr->pdc = NULL; 64 65 /* allocate and initialize pdc. It will be used later. */ 66 obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL); 67 if (!obj_list) { 68 printk(KERN_ERR "Memory allocation error\n"); 69 return; 70 } 71 72 obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL); 73 if (!obj) { 74 printk(KERN_ERR "Memory allocation error\n"); 75 kfree(obj_list); 76 return; 77 } 78 79 buf = kmalloc(12, GFP_KERNEL); 80 if (!buf) { 81 printk(KERN_ERR "Memory allocation error\n"); 82 kfree(obj); 83 kfree(obj_list); 84 return; 85 } 86 87 acpi_set_pdc_bits(buf); 88 89 obj->type = ACPI_TYPE_BUFFER; 90 obj->buffer.length = 12; 91 obj->buffer.pointer = (u8 *) buf; 92 obj_list->count = 1; 93 obj_list->pointer = obj; 94 pr->pdc = obj_list; 95 96 return; 97} 98 99/* 100 * _PDC is required for a BIOS-OS handshake for most of the newer 101 * ACPI processor features. 102 */ 103static int acpi_processor_eval_pdc(struct acpi_processor *pr) 104{ 105 struct acpi_object_list *pdc_in = pr->pdc; 106 acpi_status status = AE_OK; 107 108 if (!pdc_in) 109 return status; 110 if (idle_nomwait) { 111 /* 112 * If mwait is disabled for CPU C-states, the C2C3_FFH access 113 * mode will be disabled in the parameter of _PDC object. 114 * Of course C1_FFH access mode will also be disabled. 115 */ 116 union acpi_object *obj; 117 u32 *buffer = NULL; 118 119 obj = pdc_in->pointer; 120 buffer = (u32 *)(obj->buffer.pointer); 121 buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH); 122 123 } 124 status = acpi_evaluate_object(pr->handle, "_PDC", pdc_in, NULL); 125 126 if (ACPI_FAILURE(status)) 127 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 128 "Could not evaluate _PDC, using legacy perf. control.\n")); 129 130 return status; 131} 132 133static void acpi_processor_cleanup_pdc(struct acpi_processor *pr) 134{ 135 if (pr->pdc) { 136 kfree(pr->pdc->pointer->buffer.pointer); 137 kfree(pr->pdc->pointer); 138 kfree(pr->pdc); 139 pr->pdc = NULL; 140 } 141} 142 143void acpi_processor_set_pdc(struct acpi_processor *pr) 144{ 145 if (arch_has_acpi_pdc() == false) 146 return; 147 148 acpi_processor_init_pdc(pr); 149 acpi_processor_eval_pdc(pr); 150 acpi_processor_cleanup_pdc(pr); 151} 152EXPORT_SYMBOL_GPL(acpi_processor_set_pdc); 153 154static acpi_status 155early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv) 156{ 157 struct acpi_processor pr; 158 159 pr.handle = handle; 160 161 /* x86 implementation looks at pr.id to determine some 162 * CPU capabilites. We can just hard code to 0 since we're 163 * assuming the CPUs in the system are homogenous and all 164 * have the same capabilities. 165 */ 166 pr.id = 0; 167 168 acpi_processor_set_pdc(&pr); 169 170 return AE_OK; 171} 172 173void acpi_early_processor_set_pdc(void) 174{ 175 /* 176 * Check whether the system is DMI table. If yes, OSPM 177 * should not use mwait for CPU-states. 178 */ 179 dmi_check_system(processor_idle_dmi_table); 180 181 acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT, 182 ACPI_UINT32_MAX, 183 early_init_pdc, NULL, NULL, NULL); 184} 185