From b332b8bc9c67165eabdfc7d10b4a2e4cc9f937d0 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Fri, 7 Dec 2007 00:58:55 -0800 Subject: [PATCH] [SPARC64]: Fix memory controller register access when non-SMP. get_cpu() always returns zero on non-SMP builds, but we really want the physical cpu number in this code in order to do the right thing. Based upon a non-SMP kernel boot failure report from Bernd Zeimetz. Signed-off-by: David S. Miller --- arch/sparc64/kernel/chmc.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/arch/sparc64/kernel/chmc.c b/arch/sparc64/kernel/chmc.c index 777d34577045..6d4f02e8a4cf 100644 --- a/arch/sparc64/kernel/chmc.c +++ b/arch/sparc64/kernel/chmc.c @@ -1,7 +1,6 @@ -/* $Id: chmc.c,v 1.4 2002/01/08 16:00:14 davem Exp $ - * memctrlr.c: Driver for UltraSPARC-III memory controller. +/* memctrlr.c: Driver for UltraSPARC-III memory controller. * - * Copyright (C) 2001 David S. Miller (davem@redhat.com) + * Copyright (C) 2001, 2007 David S. Miller (davem@davemloft.net) */ #include @@ -16,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -242,8 +242,11 @@ int chmc_getunumber(int syndrome_code, */ static u64 read_mcreg(struct mctrl_info *mp, unsigned long offset) { - unsigned long ret; - int this_cpu = get_cpu(); + unsigned long ret, this_cpu; + + preempt_disable(); + + this_cpu = real_hard_smp_processor_id(); if (mp->portid == this_cpu) { __asm__ __volatile__("ldxa [%1] %2, %0" @@ -255,7 +258,8 @@ static u64 read_mcreg(struct mctrl_info *mp, unsigned long offset) : "r" (mp->regs + offset), "i" (ASI_PHYS_BYPASS_EC_E)); } - put_cpu(); + + preempt_enable(); return ret; }