summaryrefslogtreecommitdiffstats
path: root/drivers/acpi/processor_pdc.c
blob: 813f1b78c16a91bf294cc191960e58a33c63e493 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2005 Intel Corporation
 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
 *
 *      Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
 *      - Added _PDC for platforms with Intel CPUs
 */

#define pr_fmt(fmt) "ACPI: " fmt

#include <linux/dmi.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <acpi/processor.h>

#include "internal.h"

#define _COMPONENT              ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("processor_pdc");

static bool __init processor_physically_present(acpi_handle handle)
{
	int cpuid, type;
	u32 acpi_id;
	acpi_status status;
	acpi_object_type acpi_type;
	unsigned long long tmp;
	union acpi_object object = { 0 };
	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };

	status = acpi_get_type(handle, &acpi_type);
	if (ACPI_FAILURE(status))
		return false;

	switch (acpi_type) {
	case ACPI_TYPE_PROCESSOR:
		status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
		if (ACPI_FAILURE(status))
			return false;
		acpi_id = object.processor.proc_id;
		break;
	case ACPI_TYPE_DEVICE:
		status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
		if (ACPI_FAILURE(status))
			return false;
		acpi_id = tmp;
		break;
	default:
		return false;
	}

	type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
	cpuid = acpi_get_cpuid(handle, type, acpi_id);

	return !invalid_logical_cpuid(cpuid);
}

static void acpi_set_pdc_bits(u32 *buf)
{
	buf[0] = ACPI_PDC_REVISION_ID;
	buf[1] = 1;

	/* Enable coordination with firmware's _TSD info */
	buf[2] = ACPI_PDC_SMP_T_SWCOORD;

	/* Twiddle arch-specific bits needed for _PDC */
	arch_acpi_set_pdc_bits(buf);
}

static struct acpi_object_list *acpi_processor_alloc_pdc(void)
{
	struct acpi_object_list *obj_list;
	union acpi_object *obj;
	u32 *buf;

	/* allocate and initialize pdc. It will be used later. */
	obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL);
	if (!obj_list)
		goto out;

	obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
	if (!obj) {
		kfree(obj_list);
		goto out;
	}

	buf = kmalloc(12, GFP_KERNEL);
	if (!buf) {
		kfree(obj);
		kfree(obj_list);
		goto out;
	}

	acpi_set_pdc_bits(buf);

	obj->type = ACPI_TYPE_BUFFER;
	obj->buffer.length = 12;
	obj->buffer.pointer = (u8 *) buf;
	obj_list->count = 1;
	obj_list->pointer = obj;

	return obj_list;
out:
	pr_err("Memory allocation error\n");
	return NULL;
}

/*
 * _PDC is required for a BIOS-OS handshake for most of the newer
 * ACPI processor features.
 */
static acpi_status
acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
{
	acpi_status status = AE_OK;

	if (boot_option_idle_override == IDLE_NOMWAIT) {
		/*
		 * If mwait is disabled for CPU C-states, the C2C3_FFH access
		 * mode will be disabled in the parameter of _PDC object.
		 * Of course C1_FFH access mode will also be disabled.
		 */
		union acpi_object *obj;
		u32 *buffer = NULL;

		obj = pdc_in->pointer;
		buffer = (u32 *)(obj->buffer.pointer);
		buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH);

	}
	status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL);

	if (ACPI_FAILURE(status))
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
		    "Could not evaluate _PDC, using legacy perf. control.\n"));

	return status;
}

void acpi_processor_set_pdc(acpi_handle handle)
{
	struct acpi_object_list *obj_list;

	if (arch_has_acpi_pdc() == false)
		return;

	obj_list = acpi_processor_alloc_pdc();
	if (!obj_list)
		return;

	acpi_processor_eval_pdc(handle, obj_list);

	kfree(obj_list->pointer->buffer.pointer);
	kfree(obj_list->pointer);
	kfree(obj_list);
}

static acpi_status __init
early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
{
	if (processor_physically_present(handle) == false)
		return AE_OK;

	acpi_processor_set_pdc(handle);
	return AE_OK;
}

static int __init set_no_mwait(const struct dmi_system_id *id)
{
	pr_notice("%s detected - disabling mwait for CPU C-states\n",
		  id->ident);
	boot_option_idle_override = IDLE_NOMWAIT;
	return 0;
}

static const struct dmi_system_id processor_idle_dmi_table[] __initconst = {
	{
	set_no_mwait, "Extensa 5220", {
	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
	DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
	DMI_MATCH(DMI_PRODUCT_VERSION, "0100"),
	DMI_MATCH(DMI_BOARD_NAME, "Columbia") }, NULL},
	{},
};

static void __init processor_dmi_check(void)
{
	/*
	 * Check whether the system is DMI table. If yes, OSPM
	 * should not use mwait for CPU-states.
	 */
	dmi_check_system(processor_idle_dmi_table);
}

void __init acpi_early_processor_set_pdc(void)
{
	processor_dmi_check();

	acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
			    ACPI_UINT32_MAX,
			    early_init_pdc, NULL, NULL, NULL);
	acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, early_init_pdc, NULL, NULL);
}