powerpc: Avoid extra indirect function call in sending IPIs
On many platforms (including pSeries), smp_ops->message_pass is always
smp_muxed_ipi_message_pass. This changes arch/powerpc/kernel/smp.c so
that if smp_ops->message_pass is NULL, it calls smp_muxed_ipi_message_pass
directly.
This means that a platform doesn't need to set both .message_pass and
.cause_ipi, only one of them. It is a slight performance improvement
in that it gets rid of an indirect function call at the expense of a
predictable conditional branch.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 8ebc670..2975f64 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -238,15 +238,25 @@
}
#endif /* CONFIG_PPC_SMP_MUXED_IPI */
+static inline void do_message_pass(int cpu, int msg)
+{
+ if (smp_ops->message_pass)
+ smp_ops->message_pass(cpu, msg);
+#ifdef CONFIG_PPC_SMP_MUXED_IPI
+ else
+ smp_muxed_ipi_message_pass(cpu, msg);
+#endif
+}
+
void smp_send_reschedule(int cpu)
{
if (likely(smp_ops))
- smp_ops->message_pass(cpu, PPC_MSG_RESCHEDULE);
+ do_message_pass(cpu, PPC_MSG_RESCHEDULE);
}
void arch_send_call_function_single_ipi(int cpu)
{
- smp_ops->message_pass(cpu, PPC_MSG_CALL_FUNC_SINGLE);
+ do_message_pass(cpu, PPC_MSG_CALL_FUNC_SINGLE);
}
void arch_send_call_function_ipi_mask(const struct cpumask *mask)
@@ -254,7 +264,7 @@
unsigned int cpu;
for_each_cpu(cpu, mask)
- smp_ops->message_pass(cpu, PPC_MSG_CALL_FUNCTION);
+ do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
}
#if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
@@ -268,7 +278,7 @@
for_each_online_cpu(cpu)
if (cpu != me)
- smp_ops->message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
+ do_message_pass(cpu, PPC_MSG_DEBUGGER_BREAK);
}
#endif