summaryrefslogtreecommitdiff
path: root/drivers/edac/edac_module.c
blob: 3cd3a236821cb61c983fb34bc56df7f6383fb2cd (plain)
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
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259

#include <linux/freezer.h>
#include <linux/kthread.h>

#include "edac_mc.h"
#include "edac_module.h"

#define EDAC_MC_VERSION "Ver: 2.0.3" __DATE__

#ifdef CONFIG_EDAC_DEBUG
/* Values of 0 to 4 will generate output */
int edac_debug_level = 1;
EXPORT_SYMBOL_GPL(edac_debug_level);
#endif

/* scope is to module level only */
struct workqueue_struct *edac_workqueue;

/* private to this file */
static struct task_struct *edac_thread;


/*
 * sysfs object: /sys/devices/system/edac
 *	need to export to other files in this modules
 */
static struct sysdev_class edac_class = {
	set_kset_name("edac"),
};
static int edac_class_valid = 0;

/*
 * edac_get_edac_class()
 *
 *	return pointer to the edac class of 'edac'
 */
struct sysdev_class *edac_get_edac_class(void)
{
	struct sysdev_class *classptr=NULL;

	if (edac_class_valid)
		classptr = &edac_class;

	return classptr;
}

/*
 * edac_register_sysfs_edac_name()
 *
 *	register the 'edac' into /sys/devices/system
 *
 * return:
 *	0  success
 *	!0 error
 */
static int edac_register_sysfs_edac_name(void)
{
	int err;

	/* create the /sys/devices/system/edac directory */
	err = sysdev_class_register(&edac_class);

	if (err) {
		debugf1("%s() error=%d\n", __func__, err);
		return err;
	}

	edac_class_valid = 1;
	return 0;
}

/*
 * sysdev_class_unregister()
 *
 *	unregister the 'edac' from /sys/devices/system
 */
static void edac_unregister_sysfs_edac_name(void)
{
	/* only if currently registered, then unregister it */
	if (edac_class_valid)
		sysdev_class_unregister(&edac_class);

	edac_class_valid = 0;
}


/*
 * Check MC status every edac_get_poll_msec().
 * Check PCI status every edac_get_poll_msec() as well.
 *
 * This where the work gets done for edac.
 *
 * SMP safe, doesn't use NMI, and auto-rate-limits.
 */
static void do_edac_check(void)
{
	debugf3("%s()\n", __func__);

	/* perform the poll activities */
	edac_check_mc_devices();
	edac_pci_do_parity_check();
}

/*
 * Action thread for EDAC to perform the POLL operations
 */
static int edac_kernel_thread(void *arg)
{
	int msec;

	while (!kthread_should_stop()) {

		do_edac_check();

		/* goto sleep for the interval */
		msec = (HZ * edac_get_poll_msec()) / 1000;
		schedule_timeout_interruptible(msec);
		try_to_freeze();
	}

	return 0;
}

/*
 * edac_workqueue_setup
 *	initialize the edac work queue for polling operations
 */
static int edac_workqueue_setup(void)
{
	edac_workqueue = create_singlethread_workqueue("edac-poller");
	if (edac_workqueue == NULL)
		return -ENODEV;
	else
		return 0;
}

/*
 * edac_workqueue_teardown
 *	teardown the edac workqueue
 */
static void edac_workqueue_teardown(void)
{
	if (edac_workqueue) {
		flush_workqueue(edac_workqueue);
		destroy_workqueue(edac_workqueue);
		edac_workqueue = NULL;
	}
}


/*
 * edac_init
 *      module initialization entry point
 */
static int __init edac_init(void)
{
	int err = 0;

	edac_printk(KERN_INFO, EDAC_MC, EDAC_MC_VERSION "\n");

	/*
	 * Harvest and clear any boot/initialization PCI parity errors
	 *
	 * FIXME: This only clears errors logged by devices present at time of
	 * 	module initialization.  We should also do an initial clear
	 *	of each newly hotplugged device.
	 */
	edac_pci_clear_parity_errors();

	/*
	 * perform the registration of the /sys/devices/system/edac object
	 */
	if (edac_register_sysfs_edac_name()) {
		edac_printk(KERN_ERR, EDAC_MC,
			"Error initializing 'edac' kobject\n");
		err = -ENODEV;
		goto error;
	}

	/* Create the MC sysfs entries, must be first
	 */
	if (edac_sysfs_memctrl_setup()) {
		edac_printk(KERN_ERR, EDAC_MC,
			"Error initializing sysfs code\n");
		err = -ENODEV;
		goto error_sysfs;
	}

	/* Create the PCI parity sysfs entries */
	if (edac_sysfs_pci_setup()) {
		edac_printk(KERN_ERR, EDAC_MC,
			"PCI: Error initializing sysfs code\n");
		err = -ENODEV;
		goto error_mem;
	}

	/* Setup/Initialize the edac_device system */
	err = edac_workqueue_setup();
	if (err) {
		edac_printk(KERN_ERR, EDAC_MC, "init WorkQueue failure\n");
		goto error_pci;
	}

	/* create our kernel thread */
	edac_thread = kthread_run(edac_kernel_thread, NULL, "kedac");

	if (IS_ERR(edac_thread)) {
		err = PTR_ERR(edac_thread);
		goto error_work;
	}

	return 0;

	/* Error teardown stack */
error_work:
	edac_workqueue_teardown();
error_pci:
	edac_sysfs_pci_teardown();
error_mem:
	edac_sysfs_memctrl_teardown();
error_sysfs:
	edac_unregister_sysfs_edac_name();
error:
	return err;
}

/*
 * edac_exit()
 *      module exit/termination function
 */
static void __exit edac_exit(void)
{
	debugf0("%s()\n", __func__);
	kthread_stop(edac_thread);

	/* tear down the various subsystems*/
	edac_workqueue_teardown();
	edac_sysfs_memctrl_teardown();
	edac_sysfs_pci_teardown();
	edac_unregister_sysfs_edac_name();
}

/*
 * Inform the kernel of our entry and exit points
 */
module_init(edac_init);
module_exit(edac_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Doug Thompson www.softwarebitmaker.com, et al");
MODULE_DESCRIPTION("Core library routines for EDAC reporting");

/* refer to *_sysfs.c files for parameters that are exported via sysfs */

#ifdef CONFIG_EDAC_DEBUG
module_param(edac_debug_level, int, 0644);
MODULE_PARM_DESC(edac_debug_level, "Debug level");
#endif