[PATCH] powerpc/xmon: check before calling xive functions

[Breno Leitao]

Currently xmon could call XIVE functions from OPAL even if the XIVE is
disabled or does not exist in the system, as in POWER8 machines.  This
causes the following exception:

 1:mon> dx
 cpu 0x1: Vector: 700 (Program Check) at [c000000423c93450]
     pc: c00000000009cfa4: opal_xive_dump+0x50/0x68
     lr: c0000000000997b8: opal_return+0x0/0x50

This patch simply checks if XIVE is enabled before calling XIVE
functions.

Suggested-by: Guilherme G. Piccoli <gpiccoli at linux.vnet.ibm.com>
Signed-off-by: Breno Leitao <leitao at debian.org>
---
 arch/powerpc/xmon/xmon.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 4679aeb84767..b34976c4a6ba 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -2508,6 +2508,12 @@ static void dump_xives(void)
 	unsigned long num;
 	int c;
 
+	if (!xive_enabled()) {
+		printf("Xive disabled on this system\n");
+
+		return;
+	}
+
 	c = inchar();
 	if (c == 'a') {
 		dump_all_xives();
-- 
2.14.2