From 7563421b13da21dd7a947f658b5299e65ed95cbe Mon Sep 17 00:00:00 2001 From: Mike Travis Date: Fri, 29 Apr 2016 16:54:06 -0500 Subject: [PATCH] x86/platform/UV: Add UV MMR Illegal Access Function This new function is generated by the UV MMR generation script to identify MMR registers and fields that are not defined for a specific UV architecture. With this switch, the immediate panic can be replaced with a message and a bad return value allowing either hardware or the emulator to diagnose the problem. It allows functions common to some UV arches to use common defines that might not be fully defined for all arches, as long as they do not reference them on the unsupported arches. Tested-by: John Estabrook Tested-by: Gary Kroening Tested-by: Nathan Zimmer Signed-off-by: Mike Travis Reviewed-by: Dimitri Sivanich Cc: Andrew Banman Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Len Brown Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Russ Anderson Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20160429215403.231926687@asylum.americas.sgi.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/apic/x2apic_uv_x.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c index 9086d95031a5..85c38494c188 100644 --- a/arch/x86/kernel/apic/x2apic_uv_x.c +++ b/arch/x86/kernel/apic/x2apic_uv_x.c @@ -55,6 +55,18 @@ EXPORT_SYMBOL_GPL(uv_apicid_hibits); static struct apic apic_x2apic_uv_x; +/* Set this to use hardware error handler instead of kernel panic */ +static int disable_uv_undefined_panic = 1; +unsigned long uv_undefined(char *str) +{ + if (likely(!disable_uv_undefined_panic)) + panic("UV: error: undefined MMR: %s\n", str); + else + pr_crit("UV: error: undefined MMR: %s\n", str); + return ~0ul; /* cause a machine fault */ +} +EXPORT_SYMBOL(uv_undefined); + static unsigned long __init uv_early_read_mmr(unsigned long addr) { unsigned long val, *mmr; -- 2.20.1