From: Mike Travis <travis@sgi.com>
Date: Mon, 1 Aug 2016 13:40:53 -0500
Subject: x86/platform/UV: Fix kernel panic running RHEL kdump kernel on UV
 systems
Git-commit: 5a52e8f822374bebc702bb2688ed8b5515bbb55b
Patch-mainline: v4.8-rc2
References: bsc#993365 fate#320837

The latest UV kernel support panics when RHEL7 kexec's the kdump kernel
to make a dumpfile.  This patch fixes the problem by turning off all UV
support if NUMA is off.

Tested-by: Frank Ramsay <framsay@sgi.com>
Tested-by: John Estabrook <estabrook@sgi.com>
Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Dimitri Sivanich <sivanich@sgi.com>
Reviewed-by: Nathan Zimmer <nzimmer@sgi.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Andrew Banman <abanman@sgi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <rja@sgi.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160801184050.577755634@asylum.americas.sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Joerg Roedel <jroedel@suse.de>
---
 arch/x86/kernel/apic/x2apic_uv_x.c | 5 +++++
 1 file changed, 5 insertions(+)

--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -223,6 +223,11 @@ static int __init uv_acpi_madt_oem_check
 	if (strncmp(oem_id, "SGI", 3) != 0)
 		return 0;
 
+	if (numa_off) {
+		pr_err("UV: NUMA is off, disabling UV support\n");
+		return 0;
+	}
+
 	/* Setup early hub type field in uv_hub_info for Node 0 */
 	uv_cpu_info->p_uv_hub_info = &uv_hub_info_node0;
 
