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