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 19 ACPI_MODULE_NAME("processor_pdc"); 20 21 static 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 29 static 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 45 static 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 57 static struct acpi_object_list *acpi_processor_alloc_pdc(void) 58 { 59 struct acpi_object_list *obj_list; 60 union acpi_object *obj; 61 u32 *buf; 62 63 /* allocate and initialize pdc. It will be used later. */ 64 obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL); 65 if (!obj_list) { 66 printk(KERN_ERR "Memory allocation error\n"); 67 return NULL; 68 } 69 70 obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL); 71 if (!obj) { 72 printk(KERN_ERR "Memory allocation error\n"); 73 kfree(obj_list); 74 return NULL; 75 } 76 77 buf = kmalloc(12, GFP_KERNEL); 78 if (!buf) { 79 printk(KERN_ERR "Memory allocation error\n"); 80 kfree(obj); 81 kfree(obj_list); 82 return NULL; 83 } 84 85 acpi_set_pdc_bits(buf); 86 87 obj->type = ACPI_TYPE_BUFFER; 88 obj->buffer.length = 12; 89 obj->buffer.pointer = (u8 *) buf; 90 obj_list->count = 1; 91 obj_list->pointer = obj; 92 93 return obj_list; 94 } 95 96 /* 97 * _PDC is required for a BIOS-OS handshake for most of the newer 98 * ACPI processor features. 99 */ 100 static int 101 acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in) 102 { 103 acpi_status status = AE_OK; 104 105 if (idle_nomwait) { 106 /* 107 * If mwait is disabled for CPU C-states, the C2C3_FFH access 108 * mode will be disabled in the parameter of _PDC object. 109 * Of course C1_FFH access mode will also be disabled. 110 */ 111 union acpi_object *obj; 112 u32 *buffer = NULL; 113 114 obj = pdc_in->pointer; 115 buffer = (u32 *)(obj->buffer.pointer); 116 buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH); 117 118 } 119 status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL); 120 121 if (ACPI_FAILURE(status)) 122 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 123 "Could not evaluate _PDC, using legacy perf. control.\n")); 124 125 return status; 126 } 127 128 void acpi_processor_set_pdc(acpi_handle handle) 129 { 130 struct acpi_object_list *obj_list; 131 132 if (arch_has_acpi_pdc() == false) 133 return; 134 135 obj_list = acpi_processor_alloc_pdc(); 136 if (!obj_list) 137 return; 138 139 acpi_processor_eval_pdc(handle, obj_list); 140 141 kfree(obj_list->pointer->buffer.pointer); 142 kfree(obj_list->pointer); 143 kfree(obj_list); 144 } 145 EXPORT_SYMBOL_GPL(acpi_processor_set_pdc); 146 147 static acpi_status 148 early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv) 149 { 150 acpi_processor_set_pdc(handle); 151 return AE_OK; 152 } 153 154 void acpi_early_processor_set_pdc(void) 155 { 156 /* 157 * Check whether the system is DMI table. If yes, OSPM 158 * should not use mwait for CPU-states. 159 */ 160 dmi_check_system(processor_idle_dmi_table); 161 162 acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT, 163 ACPI_UINT32_MAX, 164 early_init_pdc, NULL, NULL, NULL); 165 } 166