Use safe_apic_wait_icr_idle in __send_IPI_dest_field  - x86_64

From: Fernando Luis [** ISO-8859-1 charset **] VázquezCao <fernando@oss.ntt.co.jp>
Use safe_apic_wait_icr_idle to check ICR idle bit if the vector is
NMI_VECTOR to avoid potential hangups in the event of crash when kdump
tries to stop the other CPUs.

Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: Andi Kleen <ak@suse.de>

---

---
 include/asm-x86_64/ipi.h |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Index: linux/include/asm-x86_64/ipi.h
===================================================================
--- linux.orig/include/asm-x86_64/ipi.h
+++ linux/include/asm-x86_64/ipi.h
@@ -85,7 +85,10 @@ static inline void __send_IPI_dest_field
 	/*
 	 * Wait for idle.
 	 */
-	apic_wait_icr_idle();
+	if (unlikely(vector == NMI_VECTOR))
+		safe_apic_wait_icr_idle();
+	else
+		apic_wait_icr_idle();
 
 	/*
 	 * prepare target chip field