release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/edac/edac_module.c

   1 /*
   2  * edac_module.c
   3  *
   4  * (C) 2007 www.softwarebitmaker.com
   5  *
   6  * This file is licensed under the terms of the GNU General Public
   7  * License version 2. This program is licensed "as is" without any
   8  * warranty of any kind, whether express or implied.
   9  *
  10  * Author: Doug Thompson <dougthompson@xmission.com>
  11  *
  12  */
  13 #include <linux/edac.h>
  14
  15 #include "edac_core.h"
  16 #include "edac_module.h"
  17
  18 #define EDAC_VERSION "Ver: 2.1.0 " __DATE__
  19
  20 #ifdef CONFIG_EDAC_DEBUG
  21 /* Values of 0 to 4 will generate output */
  22 int edac_debug_level = 2;
  23 EXPORT_SYMBOL_GPL(edac_debug_level);
  24 #endif
  25
  26 /* scope is to module level only */
  27 struct workqueue_struct *edac_workqueue;
  28
  29 /*
  30  * sysfs object: /sys/devices/system/edac
  31  *      need to export to other files in this modules
  32  */
  33 static struct sysdev_class edac_class = {
  34         .name = "edac",
  35 };
  36 static int edac_class_valid;
  37
  38 /*
  39  * edac_op_state_to_string()
  40  */
  41 char *edac_op_state_to_string(int opstate)
  42 {
  43         if (opstate == OP_RUNNING_POLL)
  44                 return "POLLED";
  45         else if (opstate == OP_RUNNING_INTERRUPT)
  46                 return "INTERRUPT";
  47         else if (opstate == OP_RUNNING_POLL_INTR)
  48                 return "POLL-INTR";
  49         else if (opstate == OP_ALLOC)
  50                 return "ALLOC";
  51         else if (opstate == OP_OFFLINE)
  52                 return "OFFLINE";
  53
  54         return "UNKNOWN";
  55 }
  56
  57 /*
  58  * edac_get_edac_class()
  59  *
  60  *      return pointer to the edac class of 'edac'
  61  */
  62 struct sysdev_class *edac_get_edac_class(void)
  63 {
  64         struct sysdev_class *classptr = NULL;
  65
  66         if (edac_class_valid)
  67                 classptr = &edac_class;
  68
  69         return classptr;
  70 }
  71
  72 /*
  73  * edac_register_sysfs_edac_name()
  74  *
  75  *      register the 'edac' into /sys/devices/system
  76  *
  77  * return:
  78  *      0  success
  79  *      !0 error
  80  */
  81 static int edac_register_sysfs_edac_name(void)
  82 {
  83         int err;
  84
  85         /* create the /sys/devices/system/edac directory */
  86         err = sysdev_class_register(&edac_class);
  87
  88         if (err) {
  89                 debugf1("%s() error=%d\n", __func__, err);
  90                 return err;
  91         }
  92
  93         edac_class_valid = 1;
  94         return 0;
  95 }
  96
  97 /*
  98  * sysdev_class_unregister()
  99  *
 100  *      unregister the 'edac' from /sys/devices/system
 101  */
 102 static void edac_unregister_sysfs_edac_name(void)
 103 {
 104         /* only if currently registered, then unregister it */
 105         if (edac_class_valid)
 106                 sysdev_class_unregister(&edac_class);
 107
 108         edac_class_valid = 0;
 109 }
 110
 111 /*
 112  * edac_workqueue_setup
 113  *      initialize the edac work queue for polling operations
 114  */
 115 static int edac_workqueue_setup(void)
 116 {
 117         edac_workqueue = create_singlethread_workqueue("edac-poller");
 118         if (edac_workqueue == NULL)
 119                 return -ENODEV;
 120         else
 121                 return 0;
 122 }
 123
 124 /*
 125  * edac_workqueue_teardown
 126  *      teardown the edac workqueue
 127  */
 128 static void edac_workqueue_teardown(void)
 129 {
 130         if (edac_workqueue) {
 131                 flush_workqueue(edac_workqueue);
 132                 destroy_workqueue(edac_workqueue);
 133                 edac_workqueue = NULL;
 134         }
 135 }
 136
 137 /*
 138  * edac_init
 139  *      module initialization entry point
 140  */
 141 static int __init edac_init(void)
 142 {
 143         int err = 0;
 144
 145         edac_printk(KERN_INFO, EDAC_MC, EDAC_VERSION "\n");
 146
 147         edac_pci_clear_parity_errors();
 148
 149         /*
 150          * perform the registration of the /sys/devices/system/edac class object
 151          */
 152         if (edac_register_sysfs_edac_name()) {
 153                 edac_printk(KERN_ERR, EDAC_MC,
 154                         "Error initializing 'edac' kobject\n");
 155                 err = -ENODEV;
 156                 goto error;
 157         }
 158
 159         /*
 160          * now set up the mc_kset under the edac class object
 161          */
 162         err = edac_sysfs_setup_mc_kset();
 163         if (err)
 164                 goto sysfs_setup_fail;
 165
 166         /* Setup/Initialize the workq for this core */
 167         err = edac_workqueue_setup();
 168         if (err) {
 169                 edac_printk(KERN_ERR, EDAC_MC, "init WorkQueue failure\n");
 170                 goto workq_fail;
 171         }
 172
 173         return 0;
 174
 175         /* Error teardown stack */
 176 workq_fail:
 177         edac_sysfs_teardown_mc_kset();
 178
 179 sysfs_setup_fail:
 180         edac_unregister_sysfs_edac_name();
 181
 182 error:
 183         return err;
 184 }
 185
 186 /*
 187  * edac_exit()
 188  *      module exit/termination function
 189  */
 190 static void __exit edac_exit(void)
 191 {
 192         debugf0("%s()\n", __func__);
 193
 194         /* tear down the various subsystems */
 195         edac_workqueue_teardown();
 196         edac_sysfs_teardown_mc_kset();
 197         edac_unregister_sysfs_edac_name();
 198 }
 199
 200 /*
 201  * Inform the kernel of our entry and exit points
 202  */
 203 module_init(edac_init);
 204 module_exit(edac_exit);
 205
 206 MODULE_LICENSE("GPL");
 207 MODULE_AUTHOR("Doug Thompson www.softwarebitmaker.com, et al");
 208 MODULE_DESCRIPTION("Core library routines for EDAC reporting");
 209
 210 /* refer to *_sysfs.c files for parameters that are exported via sysfs */
 211
 212 #ifdef CONFIG_EDAC_DEBUG
 213 module_param(edac_debug_level, int, 0644);
 214 MODULE_PARM_DESC(edac_debug_level, "Debug level");
 215 #endif