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
 19static 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
 56static 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
 68static 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;
101out:
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 */
110static acpi_status
111acpi_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
138void 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
156static acpi_status __init
157early_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
166static 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
174static 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
184static 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
193void __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}