drivers/edac/edac_stub.c

   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 <bp@alien8.de>
   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  */
  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  */
  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 */
  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
  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);