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
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
|
// SPDX-License-Identifier: GPL-2.0+
/*
* Common ACPI functions for hot plug platforms
*
* Copyright (C) 2006 Intel Corporation
*
* All rights reserved.
*
* Send feedback to <kristen.c.accardi@intel.com>
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/pci_hotplug.h>
#include <linux/acpi.h>
#include <linux/pci-acpi.h>
#include <linux/slab.h>
#define MY_NAME "acpi_pcihp"
#define dbg(fmt, arg...) do { if (debug_acpi) printk(KERN_DEBUG "%s: %s: " fmt, MY_NAME, __func__, ## arg); } while (0)
#define err(format, arg...) printk(KERN_ERR "%s: " format, MY_NAME, ## arg)
#define info(format, arg...) printk(KERN_INFO "%s: " format, MY_NAME, ## arg)
#define warn(format, arg...) printk(KERN_WARNING "%s: " format, MY_NAME, ## arg)
#define METHOD_NAME__SUN "_SUN"
#define METHOD_NAME_OSHP "OSHP"
static bool debug_acpi;
/* acpi_run_oshp - get control of hotplug from the firmware
*
* @handle - the handle of the hotplug controller.
*/
static acpi_status acpi_run_oshp(acpi_handle handle)
{
acpi_status status;
struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };
acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
/* run OSHP */
status = acpi_evaluate_object(handle, METHOD_NAME_OSHP, NULL, NULL);
if (ACPI_FAILURE(status))
if (status != AE_NOT_FOUND)
printk(KERN_ERR "%s:%s OSHP fails=0x%x\n",
__func__, (char *)string.pointer, status);
else
dbg("%s:%s OSHP not found\n",
__func__, (char *)string.pointer);
else
pr_debug("%s:%s OSHP passes\n", __func__,
(char *)string.pointer);
kfree(string.pointer);
return status;
}
/**
* acpi_get_hp_hw_control_from_firmware
* @dev: the pci_dev of the bridge that has a hotplug controller
*
* Attempt to take hotplug control from firmware.
*/
int acpi_get_hp_hw_control_from_firmware(struct pci_dev *pdev)
{
const struct pci_host_bridge *host;
const struct acpi_pci_root *root;
acpi_status status;
acpi_handle chandle, handle;
struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL };
/*
* If there's no ACPI host bridge (i.e., ACPI support is compiled
* into the kernel but the hardware platform doesn't support ACPI),
* there's nothing to do here.
*/
host = pci_find_host_bridge(pdev->bus);
root = acpi_pci_find_root(ACPI_HANDLE(&host->dev));
if (!root)
return 0;
/*
* If _OSC exists, it determines whether we're allowed to manage
* the SHPC. We executed it while enumerating the host bridge.
*/
if (root->osc_support_set) {
if (host->native_shpc_hotplug)
return 0;
return -ENODEV;
}
/*
* In the absence of _OSC, we're always allowed to manage the SHPC.
* However, if an OSHP method is present, we must execute it so the
* firmware can transfer control to the OS, e.g., direct interrupts
* to the OS instead of to the firmware.
*
* N.B. The PCI Firmware Spec (r3.2, sec 4.8) does not endorse
* searching up the ACPI hierarchy, so the loops below are suspect.
*/
handle = ACPI_HANDLE(&pdev->dev);
if (!handle) {
/*
* This hotplug controller was not listed in the ACPI name
* space at all. Try to get ACPI handle of parent PCI bus.
*/
struct pci_bus *pbus;
for (pbus = pdev->bus; pbus; pbus = pbus->parent) {
handle = acpi_pci_get_bridge_handle(pbus);
if (handle)
break;
}
}
while (handle) {
acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
pci_info(pdev, "Requesting control of SHPC hotplug via OSHP (%s)\n",
(char *)string.pointer);
status = acpi_run_oshp(handle);
if (ACPI_SUCCESS(status))
goto got_one;
if (acpi_is_root_bridge(handle))
break;
chandle = handle;
status = acpi_get_parent(chandle, &handle);
if (ACPI_FAILURE(status))
break;
}
pci_info(pdev, "Cannot get control of SHPC hotplug\n");
kfree(string.pointer);
return -ENODEV;
got_one:
pci_info(pdev, "Gained control of SHPC hotplug (%s)\n",
(char *)string.pointer);
kfree(string.pointer);
return 0;
}
EXPORT_SYMBOL(acpi_get_hp_hw_control_from_firmware);
static int pcihp_is_ejectable(acpi_handle handle)
{
acpi_status status;
unsigned long long removable;
if (!acpi_has_method(handle, "_ADR"))
return 0;
if (acpi_has_method(handle, "_EJ0"))
return 1;
status = acpi_evaluate_integer(handle, "_RMV", NULL, &removable);
if (ACPI_SUCCESS(status) && removable)
return 1;
return 0;
}
/**
* acpi_pcihp_check_ejectable - check if handle is ejectable ACPI PCI slot
* @pbus: the PCI bus of the PCI slot corresponding to 'handle'
* @handle: ACPI handle to check
*
* Return 1 if handle is ejectable PCI slot, 0 otherwise.
*/
int acpi_pci_check_ejectable(struct pci_bus *pbus, acpi_handle handle)
{
acpi_handle bridge_handle, parent_handle;
bridge_handle = acpi_pci_get_bridge_handle(pbus);
if (!bridge_handle)
return 0;
if ((ACPI_FAILURE(acpi_get_parent(handle, &parent_handle))))
return 0;
if (bridge_handle != parent_handle)
return 0;
return pcihp_is_ejectable(handle);
}
EXPORT_SYMBOL_GPL(acpi_pci_check_ejectable);
static acpi_status
check_hotplug(acpi_handle handle, u32 lvl, void *context, void **rv)
{
int *found = (int *)context;
if (pcihp_is_ejectable(handle)) {
*found = 1;
return AE_CTRL_TERMINATE;
}
return AE_OK;
}
/**
* acpi_pci_detect_ejectable - check if the PCI bus has ejectable slots
* @handle - handle of the PCI bus to scan
*
* Returns 1 if the PCI bus has ACPI based ejectable slots, 0 otherwise.
*/
int acpi_pci_detect_ejectable(acpi_handle handle)
{
int found = 0;
if (!handle)
return found;
acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
check_hotplug, NULL, (void *)&found, NULL);
return found;
}
EXPORT_SYMBOL_GPL(acpi_pci_detect_ejectable);
module_param(debug_acpi, bool, 0644);
MODULE_PARM_DESC(debug_acpi, "Debugging mode for ACPI enabled or not");
|
