arch/s390/kernel/trace.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Tracepoint definitions for s390
   4  *
   5  * Copyright IBM Corp. 2015
   6  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  */
   8
   9 #include <linux/percpu.h>
  10 #define CREATE_TRACE_POINTS
  11 #include <asm/trace/diag.h>
  12
  13 EXPORT_TRACEPOINT_SYMBOL(s390_diagnose);
  14
  15 static DEFINE_PER_CPU(unsigned int, diagnose_trace_depth);
  16
  17 void trace_s390_diagnose_norecursion(int diag_nr)
  18 {
  19         unsigned long flags;
  20         unsigned int *depth;
  21
  22         /* Avoid lockdep recursion. */
  23         if (IS_ENABLED(CONFIG_LOCKDEP))
  24                 return;
  25         local_irq_save(flags);
  26         depth = this_cpu_ptr(&diagnose_trace_depth);
  27         if (*depth == 0) {
  28                 (*depth)++;
  29                 trace_s390_diagnose(diag_nr);
  30                 (*depth)--;
  31         }
  32         local_irq_restore(flags);
  33 }