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: 2.0.5 " __DATE__
  18
  19 #ifdef CONFIG_EDAC_DEBUG
  20 /* Values of 0 to 4 will generate output */
  21 int edac_debug_level = 2;
  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;
  36
  37 /*
  38  * edac_op_state_to_string()
  39  */
  40 char *edac_op_state_to_string(int opstate)
  41 {
  42         if (opstate == OP_RUNNING_POLL)
  43                 return "POLLED";
  44         else if (opstate == OP_RUNNING_INTERRUPT)
  45                 return "INTERRUPT";
  46         else if (opstate == OP_RUNNING_POLL_INTR)
  47                 return "POLL-INTR";
  48         else if (opstate == OP_ALLOC)
  49                 return "ALLOC";
  50         else if (opstate == OP_OFFLINE)
  51                 return "OFFLINE";
  52
  53         return "UNKNOWN";
  54 }
  55
  56 /*
  57  * edac_get_edac_class()
  58  *
  59  *      return pointer to the edac class of 'edac'
  60  */
  61 struct sysdev_class *edac_get_edac_class(void)
  62 {
  63         struct sysdev_class *classptr = NULL;
  64
  65         if (edac_class_valid)
  66                 classptr = &edac_class;
  67
  68         return classptr;
  69 }
  70
  71 /*
  72  * edac_register_sysfs_edac_name()
  73  *
  74  *      register the 'edac' into /sys/devices/system
  75  *
  76  * return:
  77  *      0  success
  78  *      !0 error
  79  */
  80 static int edac_register_sysfs_edac_name(void)
  81 {
  82         int err;
  83
  84         /* create the /sys/devices/system/edac directory */
  85         err = sysdev_class_register(&edac_class);
  86
  87         if (err) {
  88                 debugf1("%s() error=%d\n", __func__, err);
  89                 return err;
  90         }
  91
  92         edac_class_valid = 1;
  93         return 0;
  94 }
  95
  96 /*
  97  * sysdev_class_unregister()
  98  *
  99  *      unregister the 'edac' from /sys/devices/system
 100  */
 101 static void edac_unregister_sysfs_edac_name(void)
 102 {
 103         /* only if currently registered, then unregister it */
 104         if (edac_class_valid)
 105                 sysdev_class_unregister(&edac_class);
 106
 107         edac_class_valid = 0;
 108 }
 109
 110 /*
 111  * edac_workqueue_setup
 112  *      initialize the edac work queue for polling operations
 113  */
 114 static int edac_workqueue_setup(void)
 115 {
 116         edac_workqueue = create_singlethread_workqueue("edac-poller");
 117         if (edac_workqueue == NULL)
 118                 return -ENODEV;
 119         else
 120                 return 0;
 121 }
 122
 123 /*
 124  * edac_workqueue_teardown
 125  *      teardown the edac workqueue
 126  */
 127 static void edac_workqueue_teardown(void)
 128 {
 129         if (edac_workqueue) {
 130                 flush_workqueue(edac_workqueue);
 131                 destroy_workqueue(edac_workqueue);
 132                 edac_workqueue = NULL;
 133         }
 134 }
 135
 136 /*
 137  * edac_init
 138  *      module initialization entry point
 139  */
 140 static int __init edac_init(void)
 141 {
 142         int err = 0;
 143
 144         edac_printk(KERN_INFO, EDAC_MC, EDAC_MC_VERSION "\n");
 145
 146         /*
 147          * Harvest and clear any boot/initialization PCI parity errors
 148          *
 149          * FIXME: This only clears errors logged by devices present at time of
 150          *      module initialization.  We should also do an initial clear
 151          *      of each newly hotplugged device.
 152          */
 153         edac_pci_clear_parity_errors();
 154
 155         /*
 156          * perform the registration of the /sys/devices/system/edac class object
 157          */
 158         if (edac_register_sysfs_edac_name()) {
 159                 edac_printk(KERN_ERR, EDAC_MC,
 160                         "Error initializing 'edac' kobject\n");
 161                 err = -ENODEV;
 162                 goto error;
 163         }
 164
 165         /*
 166          * now set up the mc_kset under the edac class object
 167          */
 168         err = edac_sysfs_setup_mc_kset();
 169         if (err)
 170                 goto sysfs_setup_fail;
 171
 172         /* Setup/Initialize the workq for this core */
 173         err = edac_workqueue_setup();
 174         if (err) {
 175                 edac_printk(KERN_ERR, EDAC_MC, "init WorkQueue failure\n");
 176                 goto workq_fail;
 177         }
 178
 179         return 0;
 180
 181         /* Error teardown stack */
 182 workq_fail:
 183         edac_sysfs_teardown_mc_kset();
 184
 185 sysfs_setup_fail:
 186         edac_unregister_sysfs_edac_name();
 187
 188 error:
 189         return err;
 190 }
 191
 192 /*
 193  * edac_exit()
 194  *      module exit/termination function
 195  */
 196 static void __exit edac_exit(void)
 197 {
 198         debugf0("%s()\n", __func__);
 199
 200         /* tear down the various subsystems */
 201         edac_workqueue_teardown();
 202         edac_sysfs_teardown_mc_kset();
 203         edac_unregister_sysfs_edac_name();
 204 }
 205
 206 /*
 207  * Inform the kernel of our entry and exit points
 208  */
 209 module_init(edac_init);
 210 module_exit(edac_exit);
 211
 212 MODULE_LICENSE("GPL");
 213 MODULE_AUTHOR("Doug Thompson www.softwarebitmaker.com, et al");
 214 MODULE_DESCRIPTION("Core library routines for EDAC reporting");
 215
 216 /* refer to *_sysfs.c files for parameters that are exported via sysfs */
 217
 218 #ifdef CONFIG_EDAC_DEBUG
 219 module_param(edac_debug_level, int, 0644);
 220 MODULE_PARM_DESC(edac_debug_level, "Debug level");
 221 #endif