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
diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platforms/85xx/smp.c
index d6a93a1..8eef8d2 100644
--- a/arch/powerpc/platforms/85xx/smp.c
+++ b/arch/powerpc/platforms/85xx/smp.c
@@ -236,7 +236,7 @@
}
if (cpu_has_feature(CPU_FTR_DBELL)) {
- smp_85xx_ops.message_pass = smp_muxed_ipi_message_pass;
+ /* .message_pass defaults to smp_muxed_ipi_message_pass */
smp_85xx_ops.cause_ipi = doorbell_cause_ipi;
}
diff --git a/arch/powerpc/platforms/iseries/smp.c b/arch/powerpc/platforms/iseries/smp.c
index e3265ad..2df48c2 100644
--- a/arch/powerpc/platforms/iseries/smp.c
+++ b/arch/powerpc/platforms/iseries/smp.c
@@ -75,7 +75,7 @@
}
static struct smp_ops_t iSeries_smp_ops = {
- .message_pass = smp_muxed_ipi_message_pass,
+ .message_pass = NULL, /* Use smp_muxed_ipi_message_pass */
.cause_ipi = smp_iSeries_cause_ipi,
.probe = smp_iSeries_probe,
.kick_cpu = smp_iSeries_kick_cpu,
diff --git a/arch/powerpc/platforms/powermac/smp.c b/arch/powerpc/platforms/powermac/smp.c
index db092d7..d15fca3 100644
--- a/arch/powerpc/platforms/powermac/smp.c
+++ b/arch/powerpc/platforms/powermac/smp.c
@@ -447,7 +447,7 @@
/* PowerSurge-style Macs */
struct smp_ops_t psurge_smp_ops = {
- .message_pass = smp_muxed_ipi_message_pass,
+ .message_pass = NULL, /* Use smp_muxed_ipi_message_pass */
.cause_ipi = smp_psurge_cause_ipi,
.probe = smp_psurge_probe,
.kick_cpu = smp_psurge_kick_cpu,
diff --git a/arch/powerpc/platforms/pseries/smp.c b/arch/powerpc/platforms/pseries/smp.c
index fbffd7e..84dafd3 100644
--- a/arch/powerpc/platforms/pseries/smp.c
+++ b/arch/powerpc/platforms/pseries/smp.c
@@ -207,7 +207,7 @@
};
static struct smp_ops_t pSeries_xics_smp_ops = {
- .message_pass = smp_muxed_ipi_message_pass,
+ .message_pass = NULL, /* Use smp_muxed_ipi_message_pass */
.cause_ipi = NULL, /* Filled at runtime by xics_smp_probe() */
.probe = xics_smp_probe,
.kick_cpu = smp_pSeries_kick_cpu,
diff --git a/arch/powerpc/platforms/wsp/smp.c b/arch/powerpc/platforms/wsp/smp.c
index 9d20fa9..71bd105 100644
--- a/arch/powerpc/platforms/wsp/smp.c
+++ b/arch/powerpc/platforms/wsp/smp.c
@@ -75,7 +75,7 @@
}
static struct smp_ops_t a2_smp_ops = {
- .message_pass = smp_muxed_ipi_message_pass,
+ .message_pass = NULL, /* Use smp_muxed_ipi_message_pass */
.cause_ipi = doorbell_cause_ipi,
.probe = smp_a2_probe,
.kick_cpu = smp_a2_kick_cpu,