1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2005 Intel Corporation 4 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P. 5 * 6 * Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> 7 * - Added _PDC for platforms with Intel CPUs 8 */ 9 10 #define pr_fmt(fmt) "ACPI: " fmt 11 12 #include <linux/dmi.h> 13 #include <linux/slab.h> 14 #include <linux/acpi.h> 15 #include <acpi/processor.h> 16 17 #include "internal.h" 18 19 #define _COMPONENT ACPI_PROCESSOR_COMPONENT 20 ACPI_MODULE_NAME("processor_pdc"); 21 22 static bool __init processor_physically_present(acpi_handle handle) 23 { 24 int cpuid, type; 25 u32 acpi_id; 26 acpi_status status; 27 acpi_object_type acpi_type; 28 unsigned long long tmp; 29 union acpi_object object = { 0 }; 30 struct acpi_buffer buffer = { sizeof(union acpi_object), &object }; 31 32 status = acpi_get_type(handle, &acpi_type); 33 if (ACPI_FAILURE(status)) 34 return false; 35 36 switch (acpi_type) { 37 case ACPI_TYPE_PROCESSOR: 38 status = acpi_evaluate_object(handle, NULL, NULL, &buffer); 39 if (ACPI_FAILURE(status)) 40 return false; 41 acpi_id = object.processor.proc_id; 42 break; 43 case ACPI_TYPE_DEVICE: 44 status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp); 45 if (ACPI_FAILURE(status)) 46 return false; 47 acpi_id = tmp; 48 break; 49 default: 50 return false; 51 } 52 53 type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0; 54 cpuid = acpi_get_cpuid(handle, type, acpi_id); 55 56 return !invalid_logical_cpuid(cpuid); 57 } 58 59 static void acpi_set_pdc_bits(u32 *buf) 60 { 61 buf[0] = ACPI_PDC_REVISION_ID; 62 buf[1] = 1; 63 64 /* Enable coordination with firmware's _TSD info */ 65 buf[2] = ACPI_PDC_SMP_T_SWCOORD; 66 67 /* Twiddle arch-specific bits needed for _PDC */ 68 arch_acpi_set_pdc_bits(buf); 69 } 70 71 static struct acpi_object_list *acpi_processor_alloc_pdc(void) 72 { 73 struct acpi_object_list *obj_list; 74 union acpi_object *obj; 75 u32 *buf; 76 77 /* allocate and initialize pdc. It will be used later. */ 78 obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL); 79 if (!obj_list) 80 goto out; 81 82 obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL); 83 if (!obj) { 84 kfree(obj_list); 85 goto out; 86 } 87 88 buf = kmalloc(12, GFP_KERNEL); 89 if (!buf) { 90 kfree(obj); 91 kfree(obj_list); 92 goto out; 93 } 94 95 acpi_set_pdc_bits(buf); 96 97 obj->type = ACPI_TYPE_BUFFER; 98 obj->buffer.length = 12; 99 obj->buffer.pointer = (u8 *) buf; 100 obj_list->count = 1; 101 obj_list->pointer = obj; 102 103 return obj_list; 104 out: 105 pr_err("Memory allocation error\n"); 106 return NULL; 107 } 108 109 /* 110 * _PDC is required for a BIOS-OS handshake for most of the newer 111 * ACPI processor features. 112 */ 113 static acpi_status 114 acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in) 115 { 116 acpi_status status = AE_OK; 117 118 if (boot_option_idle_override == IDLE_NOMWAIT) { 119 /* 120 * If mwait is disabled for CPU C-states, the C2C3_FFH access 121 * mode will be disabled in the parameter of _PDC object. 122 * Of course C1_FFH access mode will also be disabled. 123 */ 124 union acpi_object *obj; 125 u32 *buffer = NULL; 126 127 obj = pdc_in->pointer; 128 buffer = (u32 *)(obj->buffer.pointer); 129 buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH); 130 131 } 132 status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL); 133 134 if (ACPI_FAILURE(status)) 135 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 136 "Could not evaluate _PDC, using legacy perf. control.\n")); 137 138 return status; 139 } 140 141 void acpi_processor_set_pdc(acpi_handle handle) 142 { 143 struct acpi_object_list *obj_list; 144 145 if (arch_has_acpi_pdc() == false) 146 return; 147 148 obj_list = acpi_processor_alloc_pdc(); 149 if (!obj_list) 150 return; 151 152 acpi_processor_eval_pdc(handle, obj_list); 153 154 kfree(obj_list->pointer->buffer.pointer); 155 kfree(obj_list->pointer); 156 kfree(obj_list); 157 } 158 159 static acpi_status __init 160 early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv) 161 { 162 if (processor_physically_present(handle) == false) 163 return AE_OK; 164 165 acpi_processor_set_pdc(handle); 166 return AE_OK; 167 } 168 169 static int __init set_no_mwait(const struct dmi_system_id *id) 170 { 171 pr_notice("%s detected - disabling mwait for CPU C-states\n", 172 id->ident); 173 boot_option_idle_override = IDLE_NOMWAIT; 174 return 0; 175 } 176 177 static const struct dmi_system_id processor_idle_dmi_table[] __initconst = { 178 { 179 set_no_mwait, "Extensa 5220", { 180 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"), 181 DMI_MATCH(DMI_SYS_VENDOR, "Acer"), 182 DMI_MATCH(DMI_PRODUCT_VERSION, "0100"), 183 DMI_MATCH(DMI_BOARD_NAME, "Columbia") }, NULL}, 184 {}, 185 }; 186 187 static void __init processor_dmi_check(void) 188 { 189 /* 190 * Check whether the system is DMI table. If yes, OSPM 191 * should not use mwait for CPU-states. 192 */ 193 dmi_check_system(processor_idle_dmi_table); 194 } 195 196 void __init acpi_early_processor_set_pdc(void) 197 { 198 processor_dmi_check(); 199 200 acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT, 201 ACPI_UINT32_MAX, 202 early_init_pdc, NULL, NULL, NULL); 203 acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, early_init_pdc, NULL, NULL); 204 } 205