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}