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authorChris Dearman <chris@mips.com>2009-07-10 02:06:38 -0700
committerRalf Baechle <ralf@linux-mips.org>2009-11-02 12:00:05 +0100
commit2ee0a42961c942c6a2fb70700ef4e25c0acf5fca (patch)
tree0006eb6324a92e428e6832a48f9a3b432db7d600 /arch
parentcea2be444380fc1bf665cd023ed84be7e0872d28 (diff)
downloadlinux-rt-2ee0a42961c942c6a2fb70700ef4e25c0acf5fca.tar.gz
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>
Diffstat (limited to 'arch')
-rw-r--r--arch/mips/mti-malta/malta-amon.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/mips/mti-malta/malta-amon.c b/arch/mips/mti-malta/malta-amon.c
index df9e526312a2..469d9b0cee6d 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);
}