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