sparc: Touch NMI watchdog when walking cpus and calling printk

With the increase in number of CPUs calls to functions that dump
output to console (e.g., arch_trigger_all_cpu_backtrace) can take
a long time to complete. If IRQs are disabled eventually the NMI
watchdog kicks in and creates more havoc. Avoid by telling the NMI
watchdog everything is ok.

Signed-off-by: David Ahern <david.ahern@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc/kernel/process_64.c

@@ -287,6 +287,8 @@ void arch_trigger_all_cpu_backtrace(bool include_self)
  printk(" TPC[%lx] O7[%lx] I7[%lx] RPC[%lx]\n",
  gp->tpc, gp->o7, gp->i7, gp->rpc);
  }
+
+ touch_nmi_watchdog();
  }
 
  memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
@@ -362,6 +364,8 @@ static void pmu_snapshot_all_cpus(void)
  (cpu == this_cpu ? '*' : ' '), cpu,
  pp->pcr[0], pp->pcr[1], pp->pcr[2], pp->pcr[3],
  pp->pic[0], pp->pic[1], pp->pic[2], pp->pic[3]);
+
+ touch_nmi_watchdog();
  }
 
  memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));