diff options
| author | Richard Cochran <rcochran@linutronix.de> | 2016-07-13 17:16:52 +0000 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-07-15 10:40:28 +0200 |
| commit | 4761adb6f49048cddd65553a71ea2354b2a838be (patch) | |
| tree | 7ef757ce468242ac2a814f619ae63d713723de4e | |
| parent | 26b8768868c090151aa8c337773d429e0d5ca727 (diff) | |
arm/xen: Convert to hotplug state machine
Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.
The get_cpu() in xen_starting_cpu() boils down to preempt_disable() since
we already know the CPU we run on. Disabling preemption shouldn't be required
here from what I see since it we don't switch CPUs while invoking the function.
Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: rt@linutronix.de
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20160713153336.971559670@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/arm/xen/enlighten.c | 41 | ||||
| -rw-r--r-- | include/linux/cpuhotplug.h | 1 |
2 files changed, 12 insertions, 30 deletions
diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index 75cd7345c654..d822e2313950 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -161,12 +161,11 @@ static struct notifier_block xen_pvclock_gtod_notifier = { .notifier_call = xen_pvclock_gtod_notify, }; -static void xen_percpu_init(void) +static int xen_starting_cpu(unsigned int cpu) { struct vcpu_register_vcpu_info info; struct vcpu_info *vcpup; int err; - int cpu = get_cpu(); /* * VCPUOP_register_vcpu_info cannot be called twice for the same @@ -190,7 +189,13 @@ static void xen_percpu_init(void) after_register_vcpu_info: enable_percpu_irq(xen_events_irq, 0); - put_cpu(); + return 0; +} + +static int xen_dying_cpu(unsigned int cpu) +{ + disable_percpu_irq(xen_events_irq); + return 0; } static void xen_restart(enum reboot_mode reboot_mode, const char *cmd) @@ -209,28 +214,6 @@ static void xen_power_off(void) BUG_ON(rc); } -static int xen_cpu_notification(struct notifier_block *self, - unsigned long action, - void *hcpu) -{ - switch (action) { - case CPU_STARTING: - xen_percpu_init(); - break; - case CPU_DYING: - disable_percpu_irq(xen_events_irq); - break; - default: - break; - } - - return NOTIFY_OK; -} - -static struct notifier_block xen_cpu_notifier = { - .notifier_call = xen_cpu_notification, -}; - static irqreturn_t xen_arm_callback(int irq, void *arg) { xen_hvm_evtchn_do_upcall(); @@ -351,16 +334,14 @@ static int __init xen_guest_init(void) return -EINVAL; } - xen_percpu_init(); - - register_cpu_notifier(&xen_cpu_notifier); - pv_time_ops.steal_clock = xen_stolen_accounting; static_key_slow_inc(¶virt_steal_enabled); if (xen_initial_domain()) pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier); - return 0; + return cpuhp_setup_state(CPUHP_AP_ARM_XEN_STARTING, + "AP_ARM_XEN_STARTING", xen_starting_cpu, + xen_dying_cpu); } early_initcall(xen_guest_init); diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index ad48881ba02d..4c02b52dc77f 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -47,6 +47,7 @@ enum cpuhp_state { CPUHP_AP_KVM_STARTING, CPUHP_AP_KVM_ARM_VGIC_STARTING, CPUHP_AP_KVM_ARM_TIMER_STARTING, + CPUHP_AP_ARM_XEN_STARTING, CPUHP_AP_LEDTRIG_STARTING, CPUHP_AP_NOTIFY_STARTING, CPUHP_AP_ONLINE, |