powerpc: Add support for using doorbells for SMP IPI
The e500mc supports the new msgsnd/doorbell mechanisms that were added in
the Power ISA 2.05 architecture. We use the normal level doorbell for
doing SMP IPIs at this point.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 970d66e..678fbff 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -53,6 +53,9 @@
#endif
#include <asm/kexec.h>
#include <asm/ppc-opcode.h>
+#ifdef CONFIG_FSL_BOOKE
+#include <asm/dbell.h>
+#endif
#if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
int (*__debugger)(struct pt_regs *regs);
@@ -1122,6 +1125,24 @@
#endif /* CONFIG_VSX */
#ifdef CONFIG_FSL_BOOKE
+
+void doorbell_exception(struct pt_regs *regs)
+{
+#ifdef CONFIG_SMP
+ int cpu = smp_processor_id();
+ int msg;
+
+ if (num_online_cpus() < 2)
+ return;
+
+ for (msg = 0; msg < 4; msg++)
+ if (test_and_clear_bit(msg, &dbell_smp_message[cpu]))
+ smp_message_recv(msg);
+#else
+ printk(KERN_WARNING "Received doorbell on non-smp system\n");
+#endif
+}
+
void CacheLockingException(struct pt_regs *regs, unsigned long address,
unsigned long error_code)
{