arch/s390/kernel/trace.c

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