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#define _COMPONENT              ACPI_PROCESSOR_COMPONENT
22ACPI_MODULE_NAME("processor_pdc");
23
24static bool __init processor_physically_present(acpi_handle handle)
25{
26	int cpuid, type;
27	u32 acpi_id;
28	acpi_status status;
29	acpi_object_type acpi_type;
30	unsigned long long tmp;
31	union acpi_object object = { 0 };
32	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
33
34	status = acpi_get_type(handle, &acpi_type);
35	if (ACPI_FAILURE(status))
36		return false;
37
38	switch (acpi_type) {
39	case ACPI_TYPE_PROCESSOR:
40		status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
41		if (ACPI_FAILURE(status))
42			return false;
43		acpi_id = object.processor.proc_id;
44		break;
45	case ACPI_TYPE_DEVICE:
46		status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
47		if (ACPI_FAILURE(status))
48			return false;
49		acpi_id = tmp;
50		break;
51	default:
52		return false;
53	}
54
55	if (xen_initial_domain())
56		/*
57		 * When running as a Xen dom0 the number of processors Linux
58		 * sees can be different from the real number of processors on
59		 * the system, and we still need to execute _PDC for all of
60		 * them.
61		 */
62		return xen_processor_present(acpi_id);
63
64	type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
65	cpuid = acpi_get_cpuid(handle, type, acpi_id);
66
67	return !invalid_logical_cpuid(cpuid);
68}
69
70static void acpi_set_pdc_bits(u32 *buf)
71{
72	buf[0] = ACPI_PDC_REVISION_ID;
73	buf[1] = 1;
74
75	/* Enable coordination with firmware's _TSD info */
76	buf[2] = ACPI_PDC_SMP_T_SWCOORD;
77
78	/* Twiddle arch-specific bits needed for _PDC */
79	arch_acpi_set_pdc_bits(buf);
80}
81
82static struct acpi_object_list *acpi_processor_alloc_pdc(void)
83{
84	struct acpi_object_list *obj_list;
85	union acpi_object *obj;
86	u32 *buf;
87
88	/* allocate and initialize pdc. It will be used later. */
89	obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL);
90	if (!obj_list)
91		goto out;
92
93	obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
94	if (!obj) {
95		kfree(obj_list);
96		goto out;
97	}
98
99	buf = kmalloc(12, GFP_KERNEL);
100	if (!buf) {
101		kfree(obj);
102		kfree(obj_list);
103		goto out;
104	}
105
106	acpi_set_pdc_bits(buf);
107
108	obj->type = ACPI_TYPE_BUFFER;
109	obj->buffer.length = 12;
110	obj->buffer.pointer = (u8 *) buf;
111	obj_list->count = 1;
112	obj_list->pointer = obj;
113
114	return obj_list;
115out:
116	pr_err("Memory allocation error\n");
117	return NULL;
118}
119
120/*
121 * _PDC is required for a BIOS-OS handshake for most of the newer
122 * ACPI processor features.
123 */
124static acpi_status
125acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
126{
127	acpi_status status = AE_OK;
128
129	if (boot_option_idle_override == IDLE_NOMWAIT) {
130		/*
131		 * If mwait is disabled for CPU C-states, the C2C3_FFH access
132		 * mode will be disabled in the parameter of _PDC object.
133		 * Of course C1_FFH access mode will also be disabled.
134		 */
135		union acpi_object *obj;
136		u32 *buffer = NULL;
137
138		obj = pdc_in->pointer;
139		buffer = (u32 *)(obj->buffer.pointer);
140		buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH);
141
142	}
143	status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL);
144
145	if (ACPI_FAILURE(status))
146		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
147		    "Could not evaluate _PDC, using legacy perf. control.\n"));
148
149	return status;
150}
151
152void acpi_processor_set_pdc(acpi_handle handle)
153{
154	struct acpi_object_list *obj_list;
155
156	if (arch_has_acpi_pdc() == false)
157		return;
158
159	obj_list = acpi_processor_alloc_pdc();
160	if (!obj_list)
161		return;
162
163	acpi_processor_eval_pdc(handle, obj_list);
164
165	kfree(obj_list->pointer->buffer.pointer);
166	kfree(obj_list->pointer);
167	kfree(obj_list);
168}
169
170static acpi_status __init
171early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
172{
173	if (processor_physically_present(handle) == false)
174		return AE_OK;
175
176	acpi_processor_set_pdc(handle);
177	return AE_OK;
178}
179
180static int __init set_no_mwait(const struct dmi_system_id *id)
181{
182	pr_notice("%s detected - disabling mwait for CPU C-states\n",
183		  id->ident);
184	boot_option_idle_override = IDLE_NOMWAIT;
185	return 0;
186}
187
188static const struct dmi_system_id processor_idle_dmi_table[] __initconst = {
189	{
190	set_no_mwait, "Extensa 5220", {
191	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
192	DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
193	DMI_MATCH(DMI_PRODUCT_VERSION, "0100"),
194	DMI_MATCH(DMI_BOARD_NAME, "Columbia") }, NULL},
195	{},
196};
197
198static void __init processor_dmi_check(void)
199{
200	/*
201	 * Check whether the system is DMI table. If yes, OSPM
202	 * should not use mwait for CPU-states.
203	 */
204	dmi_check_system(processor_idle_dmi_table);
205}
206
207void __init acpi_early_processor_set_pdc(void)
208{
209	processor_dmi_check();
210
211	acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
212			    ACPI_UINT32_MAX,
213			    early_init_pdc, NULL, NULL, NULL);
214	acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, early_init_pdc, NULL, NULL);
215}
216