From 0e0ba76926c37f11f38670db0cb33728f502551e Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Thu, 15 Feb 2007 19:05:29 +0100 Subject: [PATCH] [ARM] 4201/1: SMP barriers pair needed for the secondary boot process In some situations, the pen_release store in platform_secondary_init() may stay forever in the write buffer while the CPU is waiting on the boot_lock to be released in boot_secondary(). The primary CPU could never see the pen_release update without the barriers. Signed-off-by: Catalin Marinas Signed-off-by: Russell King --- arch/arm/mach-realview/platsmp.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm/mach-realview/platsmp.c b/arch/arm/mach-realview/platsmp.c index 709a9b1ac634..fce3596f9950 100644 --- a/arch/arm/mach-realview/platsmp.c +++ b/arch/arm/mach-realview/platsmp.c @@ -59,6 +59,7 @@ void __cpuinit platform_secondary_init(unsigned int cpu) * pen, then head off into the C entry point */ pen_release = -1; + smp_wmb(); /* * Synchronise with the boot thread. @@ -102,6 +103,7 @@ int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle) timeout = jiffies + (1 * HZ); while (time_before(jiffies, timeout)) { + smp_rmb(); if (pen_release == -1) break; -- 2.20.1