1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
|
/*
* xen-acpi-pad.c - Xen pad interface
*
* Copyright (c) 2012, Intel Corporation.
* Author: Liu, Jinsong <jinsong.liu@intel.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>
#include <asm/xen/hypercall.h>
#include <xen/interface/version.h>
#include <xen/xen-ops.h>
#define ACPI_PROCESSOR_AGGREGATOR_CLASS "acpi_pad"
#define ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME "Processor Aggregator"
#define ACPI_PROCESSOR_AGGREGATOR_NOTIFY 0x80
static DEFINE_MUTEX(xen_cpu_lock);
static int xen_acpi_pad_idle_cpus(unsigned int idle_nums)
{
struct xen_platform_op op;
op.cmd = XENPF_core_parking;
op.u.core_parking.type = XEN_CORE_PARKING_SET;
op.u.core_parking.idle_nums = idle_nums;
return HYPERVISOR_dom0_op(&op);
}
static int xen_acpi_pad_idle_cpus_num(void)
{
struct xen_platform_op op;
op.cmd = XENPF_core_parking;
op.u.core_parking.type = XEN_CORE_PARKING_GET;
return HYPERVISOR_dom0_op(&op)
?: op.u.core_parking.idle_nums;
}
/*
* Query firmware how many CPUs should be idle
* return -1 on failure
*/
static int acpi_pad_pur(acpi_handle handle)
{
struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
union acpi_object *package;
int num = -1;
if (ACPI_FAILURE(acpi_evaluate_object(handle, "_PUR", NULL, &buffer)))
return num;
if (!buffer.length || !buffer.pointer)
return num;
package = buffer.pointer;
if (package->type == ACPI_TYPE_PACKAGE &&
package->package.count == 2 &&
package->package.elements[0].integer.value == 1) /* rev 1 */
num = package->package.elements[1].integer.value;
kfree(buffer.pointer);
return num;
}
/* Notify firmware how many CPUs are idle */
static void acpi_pad_ost(acpi_handle handle, int stat,
uint32_t idle_nums)
{
union acpi_object params[3] = {
{.type = ACPI_TYPE_INTEGER,},
{.type = ACPI_TYPE_INTEGER,},
{.type = ACPI_TYPE_BUFFER,},
};
struct acpi_object_list arg_list = {3, params};
params[0].integer.value = ACPI_PROCESSOR_AGGREGATOR_NOTIFY;
params[1].integer.value = stat;
params[2].buffer.length = 4;
params[2].buffer.pointer = (void *)&idle_nums;
acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
}
static void acpi_pad_handle_notify(acpi_handle handle)
{
int idle_nums;
mutex_lock(&xen_cpu_lock);
idle_nums = acpi_pad_pur(handle);
if (idle_nums < 0) {
mutex_unlock(&xen_cpu_lock);
return;
}
idle_nums = xen_acpi_pad_idle_cpus(idle_nums)
?: xen_acpi_pad_idle_cpus_num();
if (idle_nums >= 0)
acpi_pad_ost(handle, 0, idle_nums);
mutex_unlock(&xen_cpu_lock);
}
static void acpi_pad_notify(acpi_handle handle, u32 event,
void *data)
{
switch (event) {
case ACPI_PROCESSOR_AGGREGATOR_NOTIFY:
acpi_pad_handle_notify(handle);
break;
default:
pr_warn("Unsupported event [0x%x]\n", event);
break;
}
}
static int acpi_pad_add(struct acpi_device *device)
{
acpi_status status;
strcpy(acpi_device_name(device), ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME);
strcpy(acpi_device_class(device), ACPI_PROCESSOR_AGGREGATOR_CLASS);
status = acpi_install_notify_handler(device->handle,
ACPI_DEVICE_NOTIFY, acpi_pad_notify, device);
if (ACPI_FAILURE(status))
return -ENODEV;
return 0;
}
static int acpi_pad_remove(struct acpi_device *device,
int type)
{
mutex_lock(&xen_cpu_lock);
xen_acpi_pad_idle_cpus(0);
mutex_unlock(&xen_cpu_lock);
acpi_remove_notify_handler(device->handle,
ACPI_DEVICE_NOTIFY, acpi_pad_notify);
return 0;
}
static const struct acpi_device_id pad_device_ids[] = {
{"ACPI000C", 0},
{"", 0},
};
static struct acpi_driver acpi_pad_driver = {
.name = "processor_aggregator",
.class = ACPI_PROCESSOR_AGGREGATOR_CLASS,
.ids = pad_device_ids,
.ops = {
.add = acpi_pad_add,
.remove = acpi_pad_remove,
},
};
static int __init xen_acpi_pad_init(void)
{
/* Only DOM0 is responsible for Xen acpi pad */
if (!xen_initial_domain())
return -ENODEV;
/* Only Xen4.2 or later support Xen acpi pad */
if (!xen_running_on_version_or_later(4, 2))
return -ENODEV;
return acpi_bus_register_driver(&acpi_pad_driver);
}
subsys_initcall(xen_acpi_pad_init);
|
