[POWERPC] pasemi: SMP timebase sync

Timebase update is simple on PA6T, since global updates can be done from
one core by writing to an SPR.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 25 insertions, 2 deletions

diff --git a/arch/powerpc/platforms/pasemi/setup.c b/arch/powerpc/platforms/pasemi/setup.c
index cabf7017c05e..2d9652b6acb3 100644
--- a/arch/powerpc/platforms/pasemi/setup.c
+++ b/arch/powerpc/platforms/pasemi/setup.c
@@ -48,13 +48,36 @@ static void pas_restart(char *cmd)
 }
 
 #ifdef CONFIG_SMP
+static DEFINE_SPINLOCK(timebase_lock);
+
+static void __devinit pas_give_timebase(void)
+{
+        unsigned long tb;
+
+        spin_lock(&timebase_lock);
+        mtspr(SPRN_TBCTL, TBCTL_FREEZE);
+        tb = mftb();
+        mtspr(SPRN_TBCTL, TBCTL_UPDATE_LOWER | (tb & 0xffffffff));
+        mtspr(SPRN_TBCTL, TBCTL_UPDATE_UPPER | (tb >> 32));
+        mtspr(SPRN_TBCTL, TBCTL_RESTART);
+        spin_unlock(&timebase_lock);
+        pr_debug("pas_give_timebase: cpu %d gave tb %lx\n",
+                 smp_processor_id(), tb);
+}
+
+static void __devinit pas_take_timebase(void)
+{
+        pr_debug("pas_take_timebase: cpu %d has tb %lx\n",
+                 smp_processor_id(), mftb());
+}
+
 struct smp_ops_t pas_smp_ops = {
         .probe          = smp_mpic_probe,
         .message_pass   = smp_mpic_message_pass,
         .kick_cpu       = smp_generic_kick_cpu,
         .setup_cpu      = smp_mpic_setup_cpu,
-        .give_timebase  = smp_generic_give_timebase,
-        .take_timebase  = smp_generic_take_timebase,
+        .give_timebase  = pas_give_timebase,
+        .take_timebase  = pas_take_timebase,
 };
 #endif /* CONFIG_SMP */