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}