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 <xen/xen.h> 18 19 #include "internal.h" 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 if (xen_initial_domain()) 53 /* 54 * When running as a Xen dom0 the number of processors Linux 55 * sees can be different from the real number of processors on 56 * the system, and we still need to execute _PDC for all of 57 * them. 58 */ 59 return xen_processor_present(acpi_id); 60 61 type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0; 62 cpuid = acpi_get_cpuid(handle, type, acpi_id); 63 64 return !invalid_logical_cpuid(cpuid); 65 } 66 67 static void acpi_set_pdc_bits(u32 *buf) 68 { 69 buf[0] = ACPI_PDC_REVISION_ID; 70 buf[1] = 1; 71 72 /* Enable coordination with firmware's _TSD info */ 73 buf[2] = ACPI_PDC_SMP_T_SWCOORD; 74 75 /* Twiddle arch-specific bits needed for _PDC */ 76 arch_acpi_set_pdc_bits(buf); 77 } 78 79 static struct acpi_object_list *acpi_processor_alloc_pdc(void) 80 { 81 struct acpi_object_list *obj_list; 82 union acpi_object *obj; 83 u32 *buf; 84 85 /* allocate and initialize pdc. It will be used later. */ 86 obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL); 87 if (!obj_list) 88 goto out; 89 90 obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL); 91 if (!obj) { 92 kfree(obj_list); 93 goto out; 94 } 95 96 buf = kmalloc(12, GFP_KERNEL); 97 if (!buf) { 98 kfree(obj); 99 kfree(obj_list); 100 goto out; 101 } 102 103 acpi_set_pdc_bits(buf); 104 105 obj->type = ACPI_TYPE_BUFFER; 106 obj->buffer.length = 12; 107 obj->buffer.pointer = (u8 *) buf; 108 obj_list->count = 1; 109 obj_list->pointer = obj; 110 111 return obj_list; 112 out: 113 pr_err("Memory allocation error\n"); 114 return NULL; 115 } 116 117 /* 118 * _PDC is required for a BIOS-OS handshake for most of the newer 119 * ACPI processor features. 120 */ 121 static acpi_status 122 acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in) 123 { 124 acpi_status status = AE_OK; 125 126 if (boot_option_idle_override == IDLE_NOMWAIT) { 127 /* 128 * If mwait is disabled for CPU C-states, the C2C3_FFH access 129 * mode will be disabled in the parameter of _PDC object. 130 * Of course C1_FFH access mode will also be disabled. 131 */ 132 union acpi_object *obj; 133 u32 *buffer = NULL; 134 135 obj = pdc_in->pointer; 136 buffer = (u32 *)(obj->buffer.pointer); 137 buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH); 138 139 } 140 status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL); 141 142 if (ACPI_FAILURE(status)) 143 acpi_handle_debug(handle, 144 "Could not evaluate _PDC, using legacy perf control\n"); 145 146 return status; 147 } 148 149 void acpi_processor_set_pdc(acpi_handle handle) 150 { 151 struct acpi_object_list *obj_list; 152 153 if (arch_has_acpi_pdc() == false) 154 return; 155 156 obj_list = acpi_processor_alloc_pdc(); 157 if (!obj_list) 158 return; 159 160 acpi_processor_eval_pdc(handle, obj_list); 161 162 kfree(obj_list->pointer->buffer.pointer); 163 kfree(obj_list->pointer); 164 kfree(obj_list); 165 } 166 167 static acpi_status __init 168 early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv) 169 { 170 if (processor_physically_present(handle) == false) 171 return AE_OK; 172 173 acpi_processor_set_pdc(handle); 174 return AE_OK; 175 } 176 177 static int __init set_no_mwait(const struct dmi_system_id *id) 178 { 179 pr_notice("%s detected - disabling mwait for CPU C-states\n", 180 id->ident); 181 boot_option_idle_override = IDLE_NOMWAIT; 182 return 0; 183 } 184 185 static const struct dmi_system_id processor_idle_dmi_table[] __initconst = { 186 { 187 set_no_mwait, "Extensa 5220", { 188 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"), 189 DMI_MATCH(DMI_SYS_VENDOR, "Acer"), 190 DMI_MATCH(DMI_PRODUCT_VERSION, "0100"), 191 DMI_MATCH(DMI_BOARD_NAME, "Columbia") }, NULL}, 192 {}, 193 }; 194 195 static void __init processor_dmi_check(void) 196 { 197 /* 198 * Check whether the system is DMI table. If yes, OSPM 199 * should not use mwait for CPU-states. 200 */ 201 dmi_check_system(processor_idle_dmi_table); 202 } 203 204 void __init acpi_early_processor_set_pdc(void) 205 { 206 processor_dmi_check(); 207 208 acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT, 209 ACPI_UINT32_MAX, 210 early_init_pdc, NULL, NULL, NULL); 211 acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, early_init_pdc, NULL, NULL); 212 } 213