From 1ba1cefc277865a0ac222f53bbbf2ebacad1559a Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 12 Nov 2012 17:29:43 +0000 Subject: [PATCH] arm: arch_timer: divorce from local_timer api Currently, the arch_timer driver is tied to the arm port, as it relies on code in arch/arm/smp.c to setup and teardown timers as cores are hotplugged on and off. The timer is registered through an arm-specific registration mechanism, preventing sharing the driver with the arm64 port. This patch moves the driver to using a cpu notifier instead, making it easier to port. Signed-off-by: Mark Rutland Acked-by: Catalin Marinas Acked-by: Marc Zyngier Acked-by: Santosh Shilimkar --- arch/arm/kernel/arch_timer.c | 52 ++++++++++++++++++++---------------- 1 file changed, 29 insertions(+), 23 deletions(-) diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c index e973cc0eaad1..c8dfec052f2d 100644 --- a/arch/arm/kernel/arch_timer.c +++ b/arch/arm/kernel/arch_timer.c @@ -21,7 +21,6 @@ #include #include -#include #include #include @@ -37,7 +36,7 @@ enum ppi_nr { static int arch_timer_ppi[MAX_TIMER_PPI]; -static struct clock_event_device __percpu **arch_timer_evt; +static struct clock_event_device __percpu *arch_timer_evt; static struct delay_timer arch_delay_timer; static bool arch_timer_use_virtual = true; @@ -63,14 +62,14 @@ static irqreturn_t inline timer_handler(const int access, static irqreturn_t arch_timer_handler_virt(int irq, void *dev_id) { - struct clock_event_device *evt = *(struct clock_event_device **)dev_id; + struct clock_event_device *evt = dev_id; return timer_handler(ARCH_TIMER_VIRT_ACCESS, evt); } static irqreturn_t arch_timer_handler_phys(int irq, void *dev_id) { - struct clock_event_device *evt = *(struct clock_event_device **)dev_id; + struct clock_event_device *evt = dev_id; return timer_handler(ARCH_TIMER_PHYS_ACCESS, evt); } @@ -141,13 +140,13 @@ static int __cpuinit arch_timer_setup(struct clock_event_device *clk) clk->set_next_event = arch_timer_set_next_event_phys; } + clk->cpumask = cpumask_of(smp_processor_id()); + clk->set_mode(CLOCK_EVT_MODE_SHUTDOWN, NULL); clockevents_config_and_register(clk, arch_timer_rate, 0xf, 0x7fffffff); - *__this_cpu_ptr(arch_timer_evt) = clk; - if (arch_timer_use_virtual) enable_percpu_irq(arch_timer_ppi[VIRT_PPI], 0); else { @@ -251,12 +250,26 @@ static void __cpuinit arch_timer_stop(struct clock_event_device *clk) clk->set_mode(CLOCK_EVT_MODE_UNUSED, clk); } -static struct local_timer_ops arch_timer_ops __cpuinitdata = { - .setup = arch_timer_setup, - .stop = arch_timer_stop, -}; +static int __cpuinit arch_timer_cpu_notify(struct notifier_block *self, + unsigned long action, void *hcpu) +{ + struct clock_event_device *evt = this_cpu_ptr(arch_timer_evt); + + switch (action & ~CPU_TASKS_FROZEN) { + case CPU_STARTING: + arch_timer_setup(evt); + break; + case CPU_DYING: + arch_timer_stop(evt); + break; + } + + return NOTIFY_OK; +} -static struct clock_event_device arch_timer_global_evt; +static struct notifier_block arch_timer_cpu_nb __cpuinitdata = { + .notifier_call = arch_timer_cpu_notify, +}; static int __init arch_timer_register(void) { @@ -267,7 +280,7 @@ static int __init arch_timer_register(void) if (err) goto out; - arch_timer_evt = alloc_percpu(struct clock_event_device *); + arch_timer_evt = alloc_percpu(struct clock_event_device); if (!arch_timer_evt) { err = -ENOMEM; goto out; @@ -303,20 +316,13 @@ static int __init arch_timer_register(void) goto out_free; } - err = local_timer_register(&arch_timer_ops); - if (err) { - /* - * We couldn't register as a local timer (could be - * because we're on a UP platform, or because some - * other local timer is already present...). Try as a - * global timer instead. - */ - arch_timer_global_evt.cpumask = cpumask_of(0); - err = arch_timer_setup(&arch_timer_global_evt); - } + err = register_cpu_notifier(&arch_timer_cpu_nb); if (err) goto out_free_irq; + /* Immediately configure the timer on the boot CPU */ + arch_timer_setup(this_cpu_ptr(arch_timer_evt)); + /* Use the architected timer for the delay loop. */ arch_delay_timer.read_current_timer = &arch_timer_read_current_timer; arch_delay_timer.freq = arch_timer_rate; -- 2.20.1