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
20ACPI_MODULE_NAME("processor_pdc");
21
22static 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
59static 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
71static 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;
104out:
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 */
113static acpi_status
114acpi_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
141void 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
159static acpi_status __init
160early_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
169static 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
177static 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
187static 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
196void __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