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 <bp@alien8.de>
  10  *                      Advanced Micro Devices Inc.
  11  */
  12
  13 #include <linux/kobject.h>
  14 #include <linux/device.h>
  15 #include <linux/edac.h>
  16 #include <linux/module.h>
  17 #include <asm/mce.h>
  18
  19 #include "mce_amd.h"
  20
  21 struct edac_mce_attr {
  22         struct attribute attr;
  23         ssize_t (*show) (struct kobject *kobj, struct edac_mce_attr *attr, char *buf);
  24         ssize_t (*store)(struct kobject *kobj, struct edac_mce_attr *attr,
  25                          const char *buf, size_t count);
  26 };
  27
  28 #define EDAC_MCE_ATTR(_name, _mode, _show, _store)                      \
  29 static struct edac_mce_attr mce_attr_##_name = __ATTR(_name, _mode, _show, _store)
  30
  31 static struct kobject *mce_kobj;
  32
  33 /*
  34  * Collect all the MCi_XXX settings
  35  */
  36 static struct mce i_mce;
  37
  38 #define MCE_INJECT_STORE(reg)                                           \
  39 static ssize_t edac_inject_##reg##_store(struct kobject *kobj,          \
  40                                          struct edac_mce_attr *attr,    \
  41                                          const char *data, size_t count)\
  42 {                                                                       \
  43         int ret = 0;                                                    \
  44         unsigned long value;                                            \
  45                                                                         \
  46         ret = kstrtoul(data, 16, &value);                               \
  47         if (ret < 0)                                                    \
  48                 printk(KERN_ERR "Error writing MCE " #reg " field.\n"); \
  49                                                                         \
  50         i_mce.reg = value;                                              \
  51                                                                         \
  52         return count;                                                   \
  53 }
  54
  55 MCE_INJECT_STORE(status);
  56 MCE_INJECT_STORE(misc);
  57 MCE_INJECT_STORE(addr);
  58
  59 #define MCE_INJECT_SHOW(reg)                                            \
  60 static ssize_t edac_inject_##reg##_show(struct kobject *kobj,           \
  61                                         struct edac_mce_attr *attr,     \
  62                                         char *buf)                      \
  63 {                                                                       \
  64         return sprintf(buf, "0x%016llx\n", i_mce.reg);                  \
  65 }
  66
  67 MCE_INJECT_SHOW(status);
  68 MCE_INJECT_SHOW(misc);
  69 MCE_INJECT_SHOW(addr);
  70
  71 EDAC_MCE_ATTR(status, 0644, edac_inject_status_show, edac_inject_status_store);
  72 EDAC_MCE_ATTR(misc, 0644, edac_inject_misc_show, edac_inject_misc_store);
  73 EDAC_MCE_ATTR(addr, 0644, edac_inject_addr_show, edac_inject_addr_store);
  74
  75 /*
  76  * This denotes into which bank we're injecting and triggers
  77  * the injection, at the same time.
  78  */
  79 static ssize_t edac_inject_bank_store(struct kobject *kobj,
  80                                       struct edac_mce_attr *attr,
  81                                       const char *data, size_t count)
  82 {
  83         int ret = 0;
  84         unsigned long value;
  85
  86         ret = kstrtoul(data, 10, &value);
  87         if (ret < 0) {
  88                 printk(KERN_ERR "Invalid bank value!\n");
  89                 return -EINVAL;
  90         }
  91
  92         if (value > 5)
  93                 if (boot_cpu_data.x86 != 0x15 || value > 6) {
  94                         printk(KERN_ERR "Non-existent MCE bank: %lu\n", value);
  95                         return -EINVAL;
  96                 }
  97
  98         i_mce.bank = value;
  99
 100         amd_decode_mce(NULL, 0, &i_mce);
 101
 102         return count;
 103 }
 104
 105 static ssize_t edac_inject_bank_show(struct kobject *kobj,
 106                                      struct edac_mce_attr *attr, char *buf)
 107 {
 108         return sprintf(buf, "%d\n", i_mce.bank);
 109 }
 110
 111 EDAC_MCE_ATTR(bank, 0644, edac_inject_bank_show, edac_inject_bank_store);
 112
 113 static struct edac_mce_attr *sysfs_attrs[] = { &mce_attr_status, &mce_attr_misc,
 114                                                &mce_attr_addr, &mce_attr_bank
 115 };
 116
 117 static int __init edac_init_mce_inject(void)
 118 {
 119         struct bus_type *edac_subsys = NULL;
 120         int i, err = 0;
 121
 122         edac_subsys = edac_get_sysfs_subsys();
 123         if (!edac_subsys)
 124                 return -EINVAL;
 125
 126         mce_kobj = kobject_create_and_add("mce", &edac_subsys->dev_root->kobj);
 127         if (!mce_kobj) {
 128                 printk(KERN_ERR "Error creating a mce kset.\n");
 129                 err = -ENOMEM;
 130                 goto err_mce_kobj;
 131         }
 132
 133         for (i = 0; i < ARRAY_SIZE(sysfs_attrs); i++) {
 134                 err = sysfs_create_file(mce_kobj, &sysfs_attrs[i]->attr);
 135                 if (err) {
 136                         printk(KERN_ERR "Error creating %s in sysfs.\n",
 137                                         sysfs_attrs[i]->attr.name);
 138                         goto err_sysfs_create;
 139                 }
 140         }
 141         return 0;
 142
 143 err_sysfs_create:
 144         while (--i >= 0)
 145                 sysfs_remove_file(mce_kobj, &sysfs_attrs[i]->attr);
 146
 147         kobject_del(mce_kobj);
 148
 149 err_mce_kobj:
 150         edac_put_sysfs_subsys();
 151
 152         return err;
 153 }
 154
 155 static void __exit edac_exit_mce_inject(void)
 156 {
 157         int i;
 158
 159         for (i = 0; i < ARRAY_SIZE(sysfs_attrs); i++)
 160                 sysfs_remove_file(mce_kobj, &sysfs_attrs[i]->attr);
 161
 162         kobject_del(mce_kobj);
 163
 164         edac_put_sysfs_subsys();
 165 }
 166
 167 module_init(edac_init_mce_inject);
 168 module_exit(edac_exit_mce_inject);
 169
 170 MODULE_LICENSE("GPL");
 171 MODULE_AUTHOR("Borislav Petkov <bp@alien8.de>");
 172 MODULE_AUTHOR("AMD Inc.");
 173 MODULE_DESCRIPTION("MCE injection facility for testing MCE decoding");