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/edac.h>
  15 #include <linux/module.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                 if (boot_cpu_data.x86 != 0x15 || value > 6) {
  93                         printk(KERN_ERR "Non-existent MCE bank: %lu\n", value);
  94                         return -EINVAL;
  95                 }
  96
  97         i_mce.bank = value;
  98
  99         amd_decode_mce(NULL, 0, &i_mce);
 100
 101         return count;
 102 }
 103
 104 static ssize_t edac_inject_bank_show(struct kobject *kobj,
 105                                      struct edac_mce_attr *attr, char *buf)
 106 {
 107         return sprintf(buf, "%d\n", i_mce.bank);
 108 }
 109
 110 EDAC_MCE_ATTR(bank, 0644, edac_inject_bank_show, edac_inject_bank_store);
 111
 112 static struct edac_mce_attr *sysfs_attrs[] = { &mce_attr_status, &mce_attr_misc,
 113                                                &mce_attr_addr, &mce_attr_bank
 114 };
 115
 116 static int __init edac_init_mce_inject(void)
 117 {
 118         struct bus_type *edac_subsys = NULL;
 119         int i, err = 0;
 120
 121         edac_subsys = edac_get_sysfs_subsys();
 122         if (!edac_subsys)
 123                 return -EINVAL;
 124
 125         mce_kobj = kobject_create_and_add("mce", &edac_subsys->dev_root->kobj);
 126         if (!mce_kobj) {
 127                 printk(KERN_ERR "Error creating a mce kset.\n");
 128                 err = -ENOMEM;
 129                 goto err_mce_kobj;
 130         }
 131
 132         for (i = 0; i < ARRAY_SIZE(sysfs_attrs); i++) {
 133                 err = sysfs_create_file(mce_kobj, &sysfs_attrs[i]->attr);
 134                 if (err) {
 135                         printk(KERN_ERR "Error creating %s in sysfs.\n",
 136                                         sysfs_attrs[i]->attr.name);
 137                         goto err_sysfs_create;
 138                 }
 139         }
 140         return 0;
 141
 142 err_sysfs_create:
 143         while (--i >= 0)
 144                 sysfs_remove_file(mce_kobj, &sysfs_attrs[i]->attr);
 145
 146         kobject_del(mce_kobj);
 147
 148 err_mce_kobj:
 149         edac_put_sysfs_subsys();
 150
 151         return err;
 152 }
 153
 154 static void __exit edac_exit_mce_inject(void)
 155 {
 156         int i;
 157
 158         for (i = 0; i < ARRAY_SIZE(sysfs_attrs); i++)
 159                 sysfs_remove_file(mce_kobj, &sysfs_attrs[i]->attr);
 160
 161         kobject_del(mce_kobj);
 162
 163         edac_put_sysfs_subsys();
 164 }
 165
 166 module_init(edac_init_mce_inject);
 167 module_exit(edac_exit_mce_inject);
 168
 169 MODULE_LICENSE("GPL");
 170 MODULE_AUTHOR("Borislav Petkov <borislav.petkov@amd.com>");
 171 MODULE_AUTHOR("AMD Inc.");
 172 MODULE_DESCRIPTION("MCE injection facility for testing MCE decoding");