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 if (cpuid == -1) 56 return false; 57 58 return true; 59 } 60 61 static void acpi_set_pdc_bits(u32 *buf) 62 { 63 buf[0] = ACPI_PDC_REVISION_ID; 64 buf[1] = 1; 65 66 /* Enable coordination with firmware's _TSD info */ 67 buf[2] = ACPI_PDC_SMP_T_SWCOORD; 68 69 /* Twiddle arch-specific bits needed for _PDC */ 70 arch_acpi_set_pdc_bits(buf); 71 } 72 73 static struct acpi_object_list *acpi_processor_alloc_pdc(void) 74 { 75 struct acpi_object_list *obj_list; 76 union acpi_object *obj; 77 u32 *buf; 78 79 /* allocate and initialize pdc. It will be used later. */ 80 obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL); 81 if (!obj_list) 82 goto out; 83 84 obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL); 85 if (!obj) { 86 kfree(obj_list); 87 goto out; 88 } 89 90 buf = kmalloc(12, GFP_KERNEL); 91 if (!buf) { 92 kfree(obj); 93 kfree(obj_list); 94 goto out; 95 } 96 97 acpi_set_pdc_bits(buf); 98 99 obj->type = ACPI_TYPE_BUFFER; 100 obj->buffer.length = 12; 101 obj->buffer.pointer = (u8 *) buf; 102 obj_list->count = 1; 103 obj_list->pointer = obj; 104 105 return obj_list; 106 out: 107 pr_err("Memory allocation error\n"); 108 return NULL; 109 } 110 111 /* 112 * _PDC is required for a BIOS-OS handshake for most of the newer 113 * ACPI processor features. 114 */ 115 static acpi_status 116 acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in) 117 { 118 acpi_status status = AE_OK; 119 120 if (boot_option_idle_override == IDLE_NOMWAIT) { 121 /* 122 * If mwait is disabled for CPU C-states, the C2C3_FFH access 123 * mode will be disabled in the parameter of _PDC object. 124 * Of course C1_FFH access mode will also be disabled. 125 */ 126 union acpi_object *obj; 127 u32 *buffer = NULL; 128 129 obj = pdc_in->pointer; 130 buffer = (u32 *)(obj->buffer.pointer); 131 buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH); 132 133 } 134 status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL); 135 136 if (ACPI_FAILURE(status)) 137 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 138 "Could not evaluate _PDC, using legacy perf. control.\n")); 139 140 return status; 141 } 142 143 void acpi_processor_set_pdc(acpi_handle handle) 144 { 145 struct acpi_object_list *obj_list; 146 147 if (arch_has_acpi_pdc() == false) 148 return; 149 150 obj_list = acpi_processor_alloc_pdc(); 151 if (!obj_list) 152 return; 153 154 acpi_processor_eval_pdc(handle, obj_list); 155 156 kfree(obj_list->pointer->buffer.pointer); 157 kfree(obj_list->pointer); 158 kfree(obj_list); 159 } 160 161 static acpi_status __init 162 early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv) 163 { 164 if (processor_physically_present(handle) == false) 165 return AE_OK; 166 167 acpi_processor_set_pdc(handle); 168 return AE_OK; 169 } 170 171 static int __init set_no_mwait(const struct dmi_system_id *id) 172 { 173 pr_notice("%s detected - disabling mwait for CPU C-states\n", 174 id->ident); 175 boot_option_idle_override = IDLE_NOMWAIT; 176 return 0; 177 } 178 179 static struct dmi_system_id processor_idle_dmi_table[] __initdata = { 180 { 181 set_no_mwait, "Extensa 5220", { 182 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"), 183 DMI_MATCH(DMI_SYS_VENDOR, "Acer"), 184 DMI_MATCH(DMI_PRODUCT_VERSION, "0100"), 185 DMI_MATCH(DMI_BOARD_NAME, "Columbia") }, NULL}, 186 {}, 187 }; 188 189 static void __init processor_dmi_check(void) 190 { 191 /* 192 * Check whether the system is DMI table. If yes, OSPM 193 * should not use mwait for CPU-states. 194 */ 195 dmi_check_system(processor_idle_dmi_table); 196 } 197 198 void __init acpi_early_processor_set_pdc(void) 199 { 200 processor_dmi_check(); 201 202 acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT, 203 ACPI_UINT32_MAX, 204 early_init_pdc, NULL, NULL, NULL); 205 acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, early_init_pdc, NULL, NULL); 206 } 207