drivers/edac/mce_amd_inj.c

   1 /*
   2  * A simple MCE injection facility for testing the MCE decoding code. This
   3  * driver should be built as module so that it can be loaded on production
   4  * kernels for testing purposes.
   5  *
   6  * This file may be distributed under the terms of the GNU General Public
   7  * License version 2.
   8  *
   9  * Copyright (c) 2010:  Borislav Petkov <borislav.petkov@amd.com>
  10  *                      Advanced Micro Devices Inc.
  11  */
  12
  13 #include <linux/kobject.h>
  14 #include <linux/sysdev.h>
  15 #include <linux/edac.h>
  16 #include <asm/mce.h>
  17
  18 #include "mce_amd.h"
  19
  20 struct edac_mce_attr {
  21         struct attribute attr;
  22         ssize_t (*show) (struct kobject *kobj, struct edac_mce_attr *attr, char *buf);
  23         ssize_t (*store)(struct kobject *kobj, struct edac_mce_attr *attr,
  24                          const char *buf, size_t count);
  25 };
  26
  27 #define EDAC_MCE_ATTR(_name, _mode, _show, _store)                      \
  28 static struct edac_mce_attr mce_attr_##_name = __ATTR(_name, _mode, _show, _store)
  29
  30 static struct kobject *mce_kobj;
  31
  32 /*
  33  * Collect all the MCi_XXX settings
  34  */
  35 static struct mce i_mce;
  36
  37 #define MCE_INJECT_STORE(reg)                                           \
  38 static ssize_t edac_inject_##reg##_store(struct kobject *kobj,          \
  39                                          struct edac_mce_attr *attr,    \
  40                                          const char *data, size_t count)\
  41 {                                                                       \
  42         int ret = 0;                                                    \
  43         unsigned long value;                                            \
  44                                                                         \
  45         ret = strict_strtoul(data, 16, &value);                         \
  46         if (ret < 0)                                                    \
  47                 printk(KERN_ERR "Error writing MCE " #reg " field.\n"); \
  48                                                                         \
  49         i_mce.reg = value;                                              \
  50                                                                         \
  51         return count;                                                   \
  52 }
  53
  54 MCE_INJECT_STORE(status);
  55 MCE_INJECT_STORE(misc);
  56 MCE_INJECT_STORE(addr);
  57
  58 #define MCE_INJECT_SHOW(reg)                                            \
  59 static ssize_t edac_inject_##reg##_show(struct kobject *kobj,           \
  60                                         struct edac_mce_attr *attr,     \
  61                                         char *buf)                      \
  62 {                                                                       \
  63         return sprintf(buf, "0x%016llx\n", i_mce.reg);                  \
  64 }
  65
  66 MCE_INJECT_SHOW(status);
  67 MCE_INJECT_SHOW(misc);
  68 MCE_INJECT_SHOW(addr);
  69
  70 EDAC_MCE_ATTR(status, 0644, edac_inject_status_show, edac_inject_status_store);
  71 EDAC_MCE_ATTR(misc, 0644, edac_inject_misc_show, edac_inject_misc_store);
  72 EDAC_MCE_ATTR(addr, 0644, edac_inject_addr_show, edac_inject_addr_store);
  73
  74 /*
  75  * This denotes into which bank we're injecting and triggers
  76  * the injection, at the same time.
  77  */
  78 static ssize_t edac_inject_bank_store(struct kobject *kobj,
  79                                       struct edac_mce_attr *attr,
  80                                       const char *data, size_t count)
  81 {
  82         int ret = 0;
  83         unsigned long value;
  84
  85         ret = strict_strtoul(data, 10, &value);
  86         if (ret < 0) {
  87                 printk(KERN_ERR "Invalid bank value!\n");
  88                 return -EINVAL;
  89         }
  90
  91         if (value > 5) {
  92                 printk(KERN_ERR "Non-existant MCE bank: %lu\n", value);
  93                 return -EINVAL;
  94         }
  95
  96         i_mce.bank = value;
  97
  98         amd_decode_mce(NULL, 0, &i_mce);
  99
 100         return count;
 101 }
 102
 103 static ssize_t edac_inject_bank_show(struct kobject *kobj,
 104                                      struct edac_mce_attr *attr, char *buf)
 105 {
 106         return sprintf(buf, "%d\n", i_mce.bank);
 107 }
 108
 109 EDAC_MCE_ATTR(bank, 0644, edac_inject_bank_show, edac_inject_bank_store);
 110
 111 static struct edac_mce_attr *sysfs_attrs[] = { &mce_attr_status, &mce_attr_misc,
 112                                                &mce_attr_addr, &mce_attr_bank
 113 };
 114
 115 static int __init edac_init_mce_inject(void)
 116 {
 117         struct sysdev_class *edac_class = NULL;
 118         int i, err = 0;
 119
 120         edac_class = edac_get_sysfs_class();
 121         if (!edac_class)
 122                 return -EINVAL;
 123
 124         mce_kobj = kobject_create_and_add("mce", &edac_class->kset.kobj);
 125         if (!mce_kobj) {
 126                 printk(KERN_ERR "Error creating a mce kset.\n");
 127                 err = -ENOMEM;
 128                 goto err_mce_kobj;
 129         }
 130
 131         for (i = 0; i < ARRAY_SIZE(sysfs_attrs); i++) {
 132                 err = sysfs_create_file(mce_kobj, &sysfs_attrs[i]->attr);
 133                 if (err) {
 134                         printk(KERN_ERR "Error creating %s in sysfs.\n",
 135                                         sysfs_attrs[i]->attr.name);
 136                         goto err_sysfs_create;
 137                 }
 138         }
 139         return 0;
 140
 141 err_sysfs_create:
 142         while (--i >= 0)
 143                 sysfs_remove_file(mce_kobj, &sysfs_attrs[i]->attr);
 144
 145         kobject_del(mce_kobj);
 146
 147 err_mce_kobj:
 148         edac_put_sysfs_class();
 149
 150         return err;
 151 }
 152
 153 static void __exit edac_exit_mce_inject(void)
 154 {
 155         int i;
 156
 157         for (i = 0; i < ARRAY_SIZE(sysfs_attrs); i++)
 158                 sysfs_remove_file(mce_kobj, &sysfs_attrs[i]->attr);
 159
 160         kobject_del(mce_kobj);
 161
 162         edac_put_sysfs_class();
 163 }
 164
 165 module_init(edac_init_mce_inject);
 166 module_exit(edac_exit_mce_inject);
 167
 168 MODULE_LICENSE("GPL");
 169 MODULE_AUTHOR("Borislav Petkov <borislav.petkov@amd.com>");
 170 MODULE_AUTHOR("AMD Inc.");
 171 MODULE_DESCRIPTION("MCE injection facility for testing MCE decoding");