[PATCH 5/7] xen: PV on HVM: support PV spinlocks

[stefano.stabellini@eu.citrix.com]

From: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

Initialize PV spinlocks on boot CPU right after native_smp_prepare_cpus
(that switch to APIC mode and initialize APIC routing); on secondary
CPUs on CPU_UP_PREPARE.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
 arch/x86/xen/enlighten.c |   17 +++++++++++++++++
 1 files changed, 17 insertions(+), 0 deletions(-)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 2f67e2e..9c1628b 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1330,6 +1330,8 @@ static int __cpuinit xen_hvm_cpu_notify(struct notifier_block *self,
 	switch (action) {
 	case CPU_UP_PREPARE:
 		per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
+		if (xen_have_vector_callback)
+			xen_init_lock_cpu(cpu);
 		break;
 	default:
 		break;
@@ -1341,6 +1343,20 @@ static struct notifier_block __cpuinitdata xen_hvm_cpu_notifier = {
 	.notifier_call	= xen_hvm_cpu_notify,
 };
 
+static void xen_hvm_spinlock_init(void)
+{
+	if (!xen_have_vector_callback)
+		return;
+	xen_init_lock_cpu(0);
+	xen_init_spinlocks();
+}
+
+static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
+{
+	native_smp_prepare_cpus(max_cpus);
+	xen_hvm_spinlock_init();
+}
+
 static void __init xen_hvm_guest_init(void)
 {
 	int r;
@@ -1360,6 +1376,7 @@ static void __init xen_hvm_guest_init(void)
 	x86_init.irqs.intr_init = xen_init_IRQ;
 	xen_hvm_init_time_ops();
 	xen_hvm_init_mmu_ops();
+	smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus;
 }
 
 static bool __init xen_hvm_platform(void)
-- 
1.5.6.5