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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 <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
This commit is contained in:
Mark Rutland 2012-11-12 17:29:43 +00:00
parent 4580104222
commit 1ba1cefc27
1 changed files with 29 additions and 23 deletions
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52
arch/arm/kernel/arch_timer.c
View File

@ -21,7 +21,6 @@
#include <linux/io.h>
#include <asm/delay.h>
#include <asm/localtimer.h>
#include <asm/arch_timer.h>
#include <asm/sched_clock.h>
@ -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);
static struct clock_event_device arch_timer_global_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 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;