KVM/arm/arm64/vgic-new: Convert to hotplug state machine

Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Eric Auger <eric.auger@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm@vger.kernel.org
Cc: kvmarm@lists.cs.columbia.edu
Cc: linux-arm-kernel@lists.infradead.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153337.900484868@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 10 insertions, 22 deletions

diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index b5cf01ace71b..544b5563720e 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -51,6 +51,7 @@ enum cpuhp_state {
         CPUHP_AP_QCOM_TIMER_STARTING,
         CPUHP_AP_MIPS_GIC_TIMER_STARTING,
         CPUHP_AP_KVM_STARTING,
+        CPUHP_AP_KVM_ARM_VGIC_INIT_STARTING,
         CPUHP_AP_KVM_ARM_VGIC_STARTING,
         CPUHP_AP_KVM_ARM_TIMER_STARTING,
         CPUHP_AP_ARM_XEN_STARTING,
diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
index a1442f7c9c4d..2c7f0d5a62ea 100644
--- a/virt/kvm/arm/vgic/vgic-init.c
+++ b/virt/kvm/arm/vgic/vgic-init.c
@@ -353,32 +353,19 @@ out:
 
 /* GENERIC PROBE */
 
-static void vgic_init_maintenance_interrupt(void *info)
+static int vgic_init_cpu_starting(unsigned int cpu)
 {
         enable_percpu_irq(kvm_vgic_global_state.maint_irq, 0);
+        return 0;
 }
 
-static int vgic_cpu_notify(struct notifier_block *self,
-                           unsigned long action, void *cpu)
-{
-        switch (action) {
-        case CPU_STARTING:
-        case CPU_STARTING_FROZEN:
-                vgic_init_maintenance_interrupt(NULL);
-                break;
-        case CPU_DYING:
-        case CPU_DYING_FROZEN:
-                disable_percpu_irq(kvm_vgic_global_state.maint_irq);
-                break;
-        }
 
-        return NOTIFY_OK;
+static int vgic_init_cpu_dying(unsigned int cpu)
+{
+        disable_percpu_irq(kvm_vgic_global_state.maint_irq);
+        return 0;
 }
 
-static struct notifier_block vgic_cpu_nb = {
-        .notifier_call = vgic_cpu_notify,
-};
-
 static irqreturn_t vgic_maintenance_handler(int irq, void *data)
 {
         /*
@@ -434,14 +421,14 @@ int kvm_vgic_hyp_init(void)
                 return ret;
         }
 
-        ret = __register_cpu_notifier(&vgic_cpu_nb);
+        ret = cpuhp_setup_state(CPUHP_AP_KVM_ARM_VGIC_INIT_STARTING,
+                                "AP_KVM_ARM_VGIC_INIT_STARTING",
+                                vgic_init_cpu_starting, vgic_init_cpu_dying);
         if (ret) {
                 kvm_err("Cannot register vgic CPU notifier\n");
                 goto out_free_irq;
         }
 
-        on_each_cpu(vgic_init_maintenance_interrupt, NULL, 1);
-
         kvm_info("vgic interrupt IRQ%d\n", kvm_vgic_global_state.maint_irq);
         return 0;