drivers/edac/edac_module.c

   1 /*
   2  * edac_module.c
   3  *
   4  * (C) 2007 www.douglaskthompson.com
   5  * This file is licensed under the terms of the GNU General Public
   6  * License version 2. This program is licensed "as is" without any
   7  * warranty of any kind, whether express or implied.
   8  *
   9  * Author: Doug Thompson <norsk5@xmission.com>
  10  *
  11  */
  12 #include <linux/edac.h>
  13
  14 #include "edac_core.h"
  15 #include "edac_module.h"
  16
  17 #define EDAC_MC_VERSION "Ver: 2.0.4 " __DATE__
  18
  19 #ifdef CONFIG_EDAC_DEBUG
  20 /* Values of 0 to 4 will generate output */
  21 int edac_debug_level = 1;
  22 EXPORT_SYMBOL_GPL(edac_debug_level);
  23 #endif
  24
  25 /* scope is to module level only */
  26 struct workqueue_struct *edac_workqueue;
  27
  28 /*
  29  * sysfs object: /sys/devices/system/edac
  30  *      need to export to other files in this modules
  31  */
  32 static struct sysdev_class edac_class = {
  33         set_kset_name("edac"),
  34 };
  35 static int edac_class_valid = 0;
  36
  37 /*
  38  * edac_get_edac_class()
  39  *
  40  *      return pointer to the edac class of 'edac'
  41  */
  42 struct sysdev_class *edac_get_edac_class(void)
  43 {
  44         struct sysdev_class *classptr=NULL;
  45
  46         if (edac_class_valid)
  47                 classptr = &edac_class;
  48
  49         return classptr;
  50 }
  51
  52 /*
  53  * edac_register_sysfs_edac_name()
  54  *
  55  *      register the 'edac' into /sys/devices/system
  56  *
  57  * return:
  58  *      0  success
  59  *      !0 error
  60  */
  61 static int edac_register_sysfs_edac_name(void)
  62 {
  63         int err;
  64
  65         /* create the /sys/devices/system/edac directory */
  66         err = sysdev_class_register(&edac_class);
  67
  68         if (err) {
  69                 debugf1("%s() error=%d\n", __func__, err);
  70                 return err;
  71         }
  72
  73         edac_class_valid = 1;
  74         return 0;
  75 }
  76
  77 /*
  78  * sysdev_class_unregister()
  79  *
  80  *      unregister the 'edac' from /sys/devices/system
  81  */
  82 static void edac_unregister_sysfs_edac_name(void)
  83 {
  84         /* only if currently registered, then unregister it */
  85         if (edac_class_valid)
  86                 sysdev_class_unregister(&edac_class);
  87
  88         edac_class_valid = 0;
  89 }
  90
  91 /*
  92  * edac_workqueue_setup
  93  *      initialize the edac work queue for polling operations
  94  */
  95 static int edac_workqueue_setup(void)
  96 {
  97         edac_workqueue = create_singlethread_workqueue("edac-poller");
  98         if (edac_workqueue == NULL)
  99                 return -ENODEV;
 100         else
 101                 return 0;
 102 }
 103
 104 /*
 105  * edac_workqueue_teardown
 106  *      teardown the edac workqueue
 107  */
 108 static void edac_workqueue_teardown(void)
 109 {
 110         if (edac_workqueue) {
 111                 flush_workqueue(edac_workqueue);
 112                 destroy_workqueue(edac_workqueue);
 113                 edac_workqueue = NULL;
 114         }
 115 }
 116
 117
 118 /*
 119  * edac_init
 120  *      module initialization entry point
 121  */
 122 static int __init edac_init(void)
 123 {
 124         int err = 0;
 125
 126         edac_printk(KERN_INFO, EDAC_MC, EDAC_MC_VERSION "\n");
 127
 128         /*
 129          * Harvest and clear any boot/initialization PCI parity errors
 130          *
 131          * FIXME: This only clears errors logged by devices present at time of
 132          *      module initialization.  We should also do an initial clear
 133          *      of each newly hotplugged device.
 134          */
 135         edac_pci_clear_parity_errors();
 136
 137         /*
 138          * perform the registration of the /sys/devices/system/edac object
 139          */
 140         if (edac_register_sysfs_edac_name()) {
 141                 edac_printk(KERN_ERR, EDAC_MC,
 142                         "Error initializing 'edac' kobject\n");
 143                 err = -ENODEV;
 144                 goto error;
 145         }
 146
 147         /* Create the MC sysfs entries, must be first
 148          */
 149         if (edac_sysfs_memctrl_setup()) {
 150                 edac_printk(KERN_ERR, EDAC_MC,
 151                         "Error initializing sysfs code\n");
 152                 err = -ENODEV;
 153                 goto error_sysfs;
 154         }
 155
 156         /* Create the PCI parity sysfs entries */
 157         if (edac_sysfs_pci_setup()) {
 158                 edac_printk(KERN_ERR, EDAC_MC,
 159                         "PCI: Error initializing sysfs code\n");
 160                 err = -ENODEV;
 161                 goto error_mem;
 162         }
 163
 164         /* Setup/Initialize the edac_device system */
 165         err = edac_workqueue_setup();
 166         if (err) {
 167                 edac_printk(KERN_ERR, EDAC_MC, "init WorkQueue failure\n");
 168                 goto error_pci;
 169         }
 170
 171         return 0;
 172
 173         /* Error teardown stack */
 174 error_pci:
 175         edac_sysfs_pci_teardown();
 176 error_mem:
 177         edac_sysfs_memctrl_teardown();
 178 error_sysfs:
 179         edac_unregister_sysfs_edac_name();
 180 error:
 181         return err;
 182 }
 183
 184 /*
 185  * edac_exit()
 186  *      module exit/termination function
 187  */
 188 static void __exit edac_exit(void)
 189 {
 190         debugf0("%s()\n", __func__);
 191
 192         /* tear down the various subsystems*/
 193         edac_workqueue_teardown();
 194         edac_sysfs_memctrl_teardown();
 195         edac_sysfs_pci_teardown();
 196         edac_unregister_sysfs_edac_name();
 197 }
 198
 199 /*
 200  * Inform the kernel of our entry and exit points
 201  */
 202 module_init(edac_init);
 203 module_exit(edac_exit);
 204
 205 MODULE_LICENSE("GPL");
 206 MODULE_AUTHOR("Doug Thompson www.softwarebitmaker.com, et al");
 207 MODULE_DESCRIPTION("Core library routines for EDAC reporting");
 208
 209 /* refer to *_sysfs.c files for parameters that are exported via sysfs */
 210
 211 #ifdef CONFIG_EDAC_DEBUG
 212 module_param(edac_debug_level, int, 0644);
 213 MODULE_PARM_DESC(edac_debug_level, "Debug level");
 214 #endif
 215