drivers/ufs/core/ufs-fault-injection.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2
   3 #include <linux/kconfig.h>
   4 #include <linux/types.h>
   5 #include <linux/fault-inject.h>
   6 #include <linux/module.h>
   7 #include <ufs/ufshcd.h>
   8 #include "ufs-fault-injection.h"
   9
  10 static int ufs_fault_get(char *buffer, const struct kernel_param *kp);
  11 static int ufs_fault_set(const char *val, const struct kernel_param *kp);
  12
  13 static const struct kernel_param_ops ufs_fault_ops = {
  14         .get = ufs_fault_get,
  15         .set = ufs_fault_set,
  16 };
  17
  18 enum { FAULT_INJ_STR_SIZE = 80 };
  19
  20 /*
  21  * For more details about fault injection, please refer to
  22  * Documentation/fault-injection/fault-injection.rst.
  23  */
  24 static char g_trigger_eh_str[FAULT_INJ_STR_SIZE];
  25 module_param_cb(trigger_eh, &ufs_fault_ops, g_trigger_eh_str, 0644);
  26 MODULE_PARM_DESC(trigger_eh,
  27         "Fault injection. trigger_eh=<interval>,<probability>,<space>,<times>");
  28 static DECLARE_FAULT_ATTR(ufs_trigger_eh_attr);
  29
  30 static char g_timeout_str[FAULT_INJ_STR_SIZE];
  31 module_param_cb(timeout, &ufs_fault_ops, g_timeout_str, 0644);
  32 MODULE_PARM_DESC(timeout,
  33         "Fault injection. timeout=<interval>,<probability>,<space>,<times>");
  34 static DECLARE_FAULT_ATTR(ufs_timeout_attr);
  35
  36 static int ufs_fault_get(char *buffer, const struct kernel_param *kp)
  37 {
  38         const char *fault_str = kp->arg;
  39
  40         return sysfs_emit(buffer, "%s\n", fault_str);
  41 }
  42
  43 static int ufs_fault_set(const char *val, const struct kernel_param *kp)
  44 {
  45         struct fault_attr *attr = NULL;
  46
  47         if (kp->arg == g_trigger_eh_str)
  48                 attr = &ufs_trigger_eh_attr;
  49         else if (kp->arg == g_timeout_str)
  50                 attr = &ufs_timeout_attr;
  51
  52         if (WARN_ON_ONCE(!attr))
  53                 return -EINVAL;
  54
  55         if (!setup_fault_attr(attr, (char *)val))
  56                 return -EINVAL;
  57
  58         strscpy(kp->arg, val, FAULT_INJ_STR_SIZE);
  59
  60         return 0;
  61 }
  62
  63 void ufs_fault_inject_hba_init(struct ufs_hba *hba)
  64 {
  65         hba->trigger_eh_attr = ufs_trigger_eh_attr;
  66         hba->timeout_attr = ufs_timeout_attr;
  67 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
  68         fault_create_debugfs_attr("trigger_eh_inject", hba->debugfs_root, &hba->trigger_eh_attr);
  69         fault_create_debugfs_attr("timeout_inject", hba->debugfs_root, &hba->timeout_attr);
  70 #endif
  71 }
  72
  73 bool ufs_trigger_eh(struct ufs_hba *hba)
  74 {
  75         return should_fail(&hba->trigger_eh_attr, 1);
  76 }
  77
  78 bool ufs_fail_completion(struct ufs_hba *hba)
  79 {
  80         return should_fail(&hba->timeout_attr, 1);
  81 }