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 <ralf@linux-mips.org>
This commit is contained in:
Chris Dearman 2009-07-10 02:06:38 -07:00 committed by Ralf Baechle
parent cea2be4443
commit 2ee0a42961

View file

@ -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);
}