[PATCH 2/2] powerpc/pseries: Skip vpa_init() for boot cpu in smp_setup_cpu()

[PATCH 2/2] powerpc/pseries: Skip vpa_init() for boot cpu in smp_setup_cpu()

[Vaibhav Jain]

During pSeries_setup_arch(), VPA for boot-cpu is first to be
initialized. However later in the boot, smp_setup_cpu() is called for
setting up VPA on boot and secondary cpus that were brought online. This
results in vpa_init() being called twice for boot-cpu and three redundant
H_REGISTER_VPA hcalls being made to the hypervisor.

Fix this by adding an extra condition in smp_set_cpu() to call vpa_init()
only on non boot-cpus.

Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
---
 arch/powerpc/platforms/pseries/smp.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/pseries/smp.c b/arch/powerpc/platforms/pseries/smp.c
index c6c2baacca9a..106f79a96edc 100644
--- a/arch/powerpc/platforms/pseries/smp.c
+++ b/arch/powerpc/platforms/pseries/smp.c
@@ -131,7 +131,12 @@ static void smp_setup_cpu(int cpu)
 	else if (cpu != boot_cpuid)
 		xics_setup_cpu();
 
-	if (firmware_has_feature(FW_FEATURE_SPLPAR))
+	/*
+	 * Initialize VPA on non-boot cpus since boot-cpu vpa was
+	 * already initialized in pSeries_setup_arch()
+	 */
+	if (firmware_has_feature(FW_FEATURE_SPLPAR) &&
+	    cpu != boot_cpuid)
 		vpa_init(cpu);
 
 	cpumask_clear_cpu(cpu, of_spin_mask);
-- 
2.55.0