From 2ee0a42961c942c6a2fb70700ef4e25c0acf5fca Mon Sep 17 00:00:00 2001 From: Chris Dearman Date: Fri, 10 Jul 2009 02:06:38 -0700 Subject: MIPS: CMP: Fix memory barriers for correct operation of amon_cpu_start Signed-off-by: Chris Dearman (chris@mips.com) Signed-off-by: Ralf Baechle diff --git a/arch/mips/mti-malta/malta-amon.c b/arch/mips/mti-malta/malta-amon.c index df9e526..469d9b0 100644 --- a/arch/mips/mti-malta/malta-amon.c +++ b/arch/mips/mti-malta/malta-amon.c @@ -70,11 +70,12 @@ void amon_cpu_start(int cpu, launch->sp = sp; launch->a0 = a0; - /* Make sure target sees parameters before the go bit */ - smp_mb(); - + smp_wmb(); /* Target must see parameters before go */ launch->flags |= LAUNCH_FGO; + smp_wmb(); /* Target must see go before we poll */ + while ((launch->flags & LAUNCH_FGONE) == 0) ; + smp_rmb(); /* Target will be updating flags soon */ pr_debug("launch: cpu%d gone!\n", cpu); } -- cgit v0.10.2