1 /*
2  * common EDAC components that must be in kernel
3  *
4  * Author: Dave Jiang <djiang@mvista.com>
5  *
6  * 2007 (c) MontaVista Software, Inc.
7  * 2010 (c) Advanced Micro Devices Inc.
8  *	    Borislav Petkov <borislav.petkov@amd.com>
9  *
10  * This file is licensed under the terms of the GNU General Public
11  * License version 2. This program is licensed "as is" without any
12  * warranty of any kind, whether express or implied.
13  *
14  */
15 #include <linux/module.h>
16 #include <linux/edac.h>
17 #include <linux/atomic.h>
18 #include <linux/device.h>
19 #include <asm/edac.h>
20 
21 int edac_op_state = EDAC_OPSTATE_INVAL;
22 EXPORT_SYMBOL_GPL(edac_op_state);
23 
24 atomic_t edac_handlers = ATOMIC_INIT(0);
25 EXPORT_SYMBOL_GPL(edac_handlers);
26 
27 int edac_err_assert = 0;
28 EXPORT_SYMBOL_GPL(edac_err_assert);
29 
30 static atomic_t edac_subsys_valid = ATOMIC_INIT(0);
31 
32 /*
33  * called to determine if there is an EDAC driver interested in
34  * knowing an event (such as NMI) occurred
35  */
edac_handler_set(void)36 int edac_handler_set(void)
37 {
38 	if (edac_op_state == EDAC_OPSTATE_POLL)
39 		return 0;
40 
41 	return atomic_read(&edac_handlers);
42 }
43 EXPORT_SYMBOL_GPL(edac_handler_set);
44 
45 /*
46  * handler for NMI type of interrupts to assert error
47  */
edac_atomic_assert_error(void)48 void edac_atomic_assert_error(void)
49 {
50 	edac_err_assert++;
51 }
52 EXPORT_SYMBOL_GPL(edac_atomic_assert_error);
53 
54 /*
55  * sysfs object: /sys/devices/system/edac
56  *	need to export to other files
57  */
58 struct bus_type edac_subsys = {
59 	.name = "edac",
60 	.dev_name = "edac",
61 };
62 EXPORT_SYMBOL_GPL(edac_subsys);
63 
64 /* return pointer to the 'edac' node in sysfs */
edac_get_sysfs_subsys(void)65 struct bus_type *edac_get_sysfs_subsys(void)
66 {
67 	int err = 0;
68 
69 	if (atomic_read(&edac_subsys_valid))
70 		goto out;
71 
72 	/* create the /sys/devices/system/edac directory */
73 	err = subsys_system_register(&edac_subsys, NULL);
74 	if (err) {
75 		printk(KERN_ERR "Error registering toplevel EDAC sysfs dir\n");
76 		return NULL;
77 	}
78 
79 out:
80 	atomic_inc(&edac_subsys_valid);
81 	return &edac_subsys;
82 }
83 EXPORT_SYMBOL_GPL(edac_get_sysfs_subsys);
84 
edac_put_sysfs_subsys(void)85 void edac_put_sysfs_subsys(void)
86 {
87 	/* last user unregisters it */
88 	if (atomic_dec_and_test(&edac_subsys_valid))
89 		bus_unregister(&edac_subsys);
90 }
91 EXPORT_SYMBOL_GPL(edac_put_sysfs_subsys);
92