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 <asm/edac.h>
19 
20 int edac_op_state = EDAC_OPSTATE_INVAL;
21 EXPORT_SYMBOL_GPL(edac_op_state);
22 
23 atomic_t edac_handlers = ATOMIC_INIT(0);
24 EXPORT_SYMBOL_GPL(edac_handlers);
25 
26 int edac_err_assert = 0;
27 EXPORT_SYMBOL_GPL(edac_err_assert);
28 
29 static atomic_t edac_subsys_valid = ATOMIC_INIT(0);
30 
31 /*
32  * called to determine if there is an EDAC driver interested in
33  * knowing an event (such as NMI) occurred
34  */
edac_handler_set(void)35 int edac_handler_set(void)
36 {
37 	if (edac_op_state == EDAC_OPSTATE_POLL)
38 		return 0;
39 
40 	return atomic_read(&edac_handlers);
41 }
42 EXPORT_SYMBOL_GPL(edac_handler_set);
43 
44 /*
45  * handler for NMI type of interrupts to assert error
46  */
edac_atomic_assert_error(void)47 void edac_atomic_assert_error(void)
48 {
49 	edac_err_assert++;
50 }
51 EXPORT_SYMBOL_GPL(edac_atomic_assert_error);
52 
53 /*
54  * sysfs object: /sys/devices/system/edac
55  *	need to export to other files
56  */
57 struct bus_type edac_subsys = {
58 	.name = "edac",
59 	.dev_name = "edac",
60 };
61 EXPORT_SYMBOL_GPL(edac_subsys);
62 
63 /* return pointer to the 'edac' node in sysfs */
edac_get_sysfs_subsys(void)64 struct bus_type *edac_get_sysfs_subsys(void)
65 {
66 	int err = 0;
67 
68 	if (atomic_read(&edac_subsys_valid))
69 		goto out;
70 
71 	/* create the /sys/devices/system/edac directory */
72 	err = subsys_system_register(&edac_subsys, NULL);
73 	if (err) {
74 		printk(KERN_ERR "Error registering toplevel EDAC sysfs dir\n");
75 		return NULL;
76 	}
77 
78 out:
79 	atomic_inc(&edac_subsys_valid);
80 	return &edac_subsys;
81 }
82 EXPORT_SYMBOL_GPL(edac_get_sysfs_subsys);
83 
edac_put_sysfs_subsys(void)84 void edac_put_sysfs_subsys(void)
85 {
86 	/* last user unregisters it */
87 	if (atomic_dec_and_test(&edac_subsys_valid))
88 		bus_unregister(&edac_subsys);
89 }
90 EXPORT_SYMBOL_GPL(edac_put_sysfs_subsys);
91