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
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
|
// SPDX-License-Identifier: GPL-2.0
/*
* This file implements the error recovery as a core part of PCIe error
* reporting. When a PCIe error is delivered, an error message will be
* collected and printed to console, then, an error recovery procedure
* will be executed by following the PCI error recovery rules.
*
* Copyright (C) 2006 Intel Corp.
* Tom Long Nguyen (tom.l.nguyen@intel.com)
* Zhang Yanmin (yanmin.zhang@intel.com)
*/
#define dev_fmt(fmt) "AER: " fmt
#include <linux/pci.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/aer.h>
#include "portdrv.h"
#include "../pci.h"
static pci_ers_result_t merge_result(enum pci_ers_result orig,
enum pci_ers_result new)
{
if (new == PCI_ERS_RESULT_NO_AER_DRIVER)
return PCI_ERS_RESULT_NO_AER_DRIVER;
if (new == PCI_ERS_RESULT_NONE)
return orig;
switch (orig) {
case PCI_ERS_RESULT_CAN_RECOVER:
case PCI_ERS_RESULT_RECOVERED:
orig = new;
break;
case PCI_ERS_RESULT_DISCONNECT:
if (new == PCI_ERS_RESULT_NEED_RESET)
orig = PCI_ERS_RESULT_NEED_RESET;
break;
default:
break;
}
return orig;
}
static int report_error_detected(struct pci_dev *dev,
pci_channel_state_t state,
enum pci_ers_result *result)
{
pci_ers_result_t vote;
const struct pci_error_handlers *err_handler;
device_lock(&dev->dev);
if (!pci_dev_set_io_state(dev, state) ||
!dev->driver ||
!dev->driver->err_handler ||
!dev->driver->err_handler->error_detected) {
/*
* If any device in the subtree does not have an error_detected
* callback, PCI_ERS_RESULT_NO_AER_DRIVER prevents subsequent
* error callbacks of "any" device in the subtree, and will
* exit in the disconnected error state.
*/
if (dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) {
vote = PCI_ERS_RESULT_NO_AER_DRIVER;
pci_info(dev, "can't recover (no error_detected callback)\n");
} else {
vote = PCI_ERS_RESULT_NONE;
}
} else {
err_handler = dev->driver->err_handler;
vote = err_handler->error_detected(dev, state);
}
pci_uevent_ers(dev, vote);
*result = merge_result(*result, vote);
device_unlock(&dev->dev);
return 0;
}
static int report_frozen_detected(struct pci_dev *dev, void *data)
{
return report_error_detected(dev, pci_channel_io_frozen, data);
}
static int report_normal_detected(struct pci_dev *dev, void *data)
{
return report_error_detected(dev, pci_channel_io_normal, data);
}
static int report_mmio_enabled(struct pci_dev *dev, void *data)
{
pci_ers_result_t vote, *result = data;
const struct pci_error_handlers *err_handler;
device_lock(&dev->dev);
if (!dev->driver ||
!dev->driver->err_handler ||
!dev->driver->err_handler->mmio_enabled)
goto out;
err_handler = dev->driver->err_handler;
vote = err_handler->mmio_enabled(dev);
*result = merge_result(*result, vote);
out:
device_unlock(&dev->dev);
return 0;
}
static int report_slot_reset(struct pci_dev *dev, void *data)
{
pci_ers_result_t vote, *result = data;
const struct pci_error_handlers *err_handler;
device_lock(&dev->dev);
if (!dev->driver ||
!dev->driver->err_handler ||
!dev->driver->err_handler->slot_reset)
goto out;
err_handler = dev->driver->err_handler;
vote = err_handler->slot_reset(dev);
*result = merge_result(*result, vote);
out:
device_unlock(&dev->dev);
return 0;
}
static int report_resume(struct pci_dev *dev, void *data)
{
const struct pci_error_handlers *err_handler;
device_lock(&dev->dev);
if (!pci_dev_set_io_state(dev, pci_channel_io_normal) ||
!dev->driver ||
!dev->driver->err_handler ||
!dev->driver->err_handler->resume)
goto out;
err_handler = dev->driver->err_handler;
err_handler->resume(dev);
out:
pci_uevent_ers(dev, PCI_ERS_RESULT_RECOVERED);
device_unlock(&dev->dev);
return 0;
}
/**
* pci_walk_bridge - walk bridges potentially AER affected
* @bridge: bridge which may be a Port or an RCEC
* @cb: callback to be called for each device found
* @userdata: arbitrary pointer to be passed to callback
*
* If the device provided is a bridge, walk the subordinate bus, including
* any bridged devices on buses under this bus. Call the provided callback
* on each device found.
*
* If the device provided has no subordinate bus, e.g., an RCEC, call the
* callback on the device itself.
*/
static void pci_walk_bridge(struct pci_dev *bridge,
int (*cb)(struct pci_dev *, void *),
void *userdata)
{
if (bridge->subordinate)
pci_walk_bus(bridge->subordinate, cb, userdata);
else
cb(bridge, userdata);
}
pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
pci_channel_state_t state,
pci_ers_result_t (*reset_subordinates)(struct pci_dev *pdev))
{
int type = pci_pcie_type(dev);
struct pci_dev *bridge;
pci_ers_result_t status = PCI_ERS_RESULT_CAN_RECOVER;
/*
* If the error was detected by a Root Port, Downstream Port, or
* RCEC, recovery runs on the device itself. For Ports, that also
* includes any subordinate devices.
*
* If it was detected by another device (Endpoint, etc), recovery
* runs on the device and anything else under the same Port, i.e.,
* everything under "bridge".
*/
if (type == PCI_EXP_TYPE_ROOT_PORT ||
type == PCI_EXP_TYPE_DOWNSTREAM ||
type == PCI_EXP_TYPE_RC_EC)
bridge = dev;
else
bridge = pci_upstream_bridge(dev);
pci_dbg(bridge, "broadcast error_detected message\n");
if (state == pci_channel_io_frozen) {
pci_walk_bridge(bridge, report_frozen_detected, &status);
if (reset_subordinates(bridge) != PCI_ERS_RESULT_RECOVERED) {
pci_warn(bridge, "subordinate device reset failed\n");
goto failed;
}
} else {
pci_walk_bridge(bridge, report_normal_detected, &status);
}
if (status == PCI_ERS_RESULT_CAN_RECOVER) {
status = PCI_ERS_RESULT_RECOVERED;
pci_dbg(bridge, "broadcast mmio_enabled message\n");
pci_walk_bridge(bridge, report_mmio_enabled, &status);
}
if (status == PCI_ERS_RESULT_NEED_RESET) {
/*
* TODO: Should call platform-specific
* functions to reset slot before calling
* drivers' slot_reset callbacks?
*/
status = PCI_ERS_RESULT_RECOVERED;
pci_dbg(bridge, "broadcast slot_reset message\n");
pci_walk_bridge(bridge, report_slot_reset, &status);
}
if (status != PCI_ERS_RESULT_RECOVERED)
goto failed;
pci_dbg(bridge, "broadcast resume message\n");
pci_walk_bridge(bridge, report_resume, &status);
if (pcie_aer_is_native(bridge))
pcie_clear_device_status(bridge);
pci_aer_clear_nonfatal_status(bridge);
pci_info(bridge, "device recovery successful\n");
return status;
failed:
pci_uevent_ers(bridge, PCI_ERS_RESULT_DISCONNECT);
/* TODO: Should kernel panic here? */
pci_info(bridge, "device recovery failed\n");
return status;
}
|
