powerpc/book3e: More doorbell cleanups. Sample the PIR register

The doorbells use the content of the PIR register to match messages
from other CPUs. This may or may not be the same as our linux CPU
number, so using that as the "target" is no right.

Instead, we sample the PIR register at boot on every processor
and use that value subsequently when sending IPIs.

We also use a per-cpu message mask rather than a global array which
should limit cache line contention.

Note: We could use the CPU number in the device-tree instead of
the PIR register, as they are supposed to be equivalent. This
might prove useful if doorbells are to be used to kick CPUs out
of FW at boot time, thus before we can sample the PIR. This is
however not the case now and using the PIR just works.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platforms/85xx/smp.c
index a15f582300d..4c3cde911c7 100644
--- a/arch/powerpc/platforms/85xx/smp.c
+++ b/arch/powerpc/platforms/85xx/smp.c
@@ -99,6 +99,8 @@ static void __init
 smp_85xx_setup_cpu(int cpu_nr)
 {
 	mpic_setup_this_cpu();
+	if (cpu_has_feature(CPU_FTR_DBELL))
+		doorbell_setup_this_cpu();
 }
 
 struct smp_ops_t smp_85xx_ops = {
@@ -117,7 +119,7 @@ void __init mpc85xx_smp_init(void)
 	}
 
 	if (cpu_has_feature(CPU_FTR_DBELL))
-		smp_85xx_ops.message_pass = smp_dbell_message_pass;
+		smp_85xx_ops.message_pass = doorbell_message_pass;
 
 	BUG_ON(!smp_85xx_ops.message_pass);