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path: root/drivers/clocksource/arm_arch_timer.c
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Diffstat (limited to 'drivers/clocksource/arm_arch_timer.c')
-rw-r--r--drivers/clocksource/arm_arch_timer.c55
1 files changed, 54 insertions, 1 deletions
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index fbd9ccd..95fb944 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -13,12 +13,14 @@
#include <linux/device.h>
#include <linux/smp.h>
#include <linux/cpu.h>
+#include <linux/cpu_pm.h>
#include <linux/clockchips.h>
#include <linux/interrupt.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <linux/io.h>
#include <linux/slab.h>
+#include <linux/sched_clock.h>
#include <asm/arch_timer.h>
#include <asm/virt.h>
@@ -294,6 +296,19 @@ static void __arch_timer_setup(unsigned type,
clockevents_config_and_register(clk, arch_timer_rate, 0xf, 0x7fffffff);
}
+static void arch_timer_configure_evtstream(void)
+{
+ int evt_stream_div, pos;
+
+ /* Find the closest power of two to the divisor */
+ evt_stream_div = arch_timer_rate / ARCH_TIMER_EVT_STREAM_FREQ;
+ pos = fls(evt_stream_div);
+ if (pos > 1 && !(evt_stream_div & (1 << (pos - 2))))
+ pos--;
+ /* enable event stream */
+ arch_timer_evtstrm_enable(min(pos, 15));
+}
+
static int arch_timer_setup(struct clock_event_device *clk)
{
__arch_timer_setup(ARCH_CP15_TIMER, clk);
@@ -307,6 +322,8 @@ static int arch_timer_setup(struct clock_event_device *clk)
}
arch_counter_set_user_access();
+ if (IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM))
+ arch_timer_configure_evtstream();
return 0;
}
@@ -389,7 +406,7 @@ static struct clocksource clocksource_counter = {
.rating = 400,
.read = arch_counter_read,
.mask = CLOCKSOURCE_MASK(56),
- .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_SUSPEND_NONSTOP,
};
static struct cyclecounter cyclecounter = {
@@ -419,6 +436,9 @@ static void __init arch_counter_register(unsigned type)
cyclecounter.mult = clocksource_counter.mult;
cyclecounter.shift = clocksource_counter.shift;
timecounter_init(&timecounter, &cyclecounter, start_count);
+
+ /* 56 bits minimum, so we assume worst case rollover */
+ sched_clock_register(arch_timer_read_counter, 56, arch_timer_rate);
}
static void arch_timer_stop(struct clock_event_device *clk)
@@ -460,6 +480,33 @@ static struct notifier_block arch_timer_cpu_nb = {
.notifier_call = arch_timer_cpu_notify,
};
+#ifdef CONFIG_CPU_PM
+static unsigned int saved_cntkctl;
+static int arch_timer_cpu_pm_notify(struct notifier_block *self,
+ unsigned long action, void *hcpu)
+{
+ if (action == CPU_PM_ENTER)
+ saved_cntkctl = arch_timer_get_cntkctl();
+ else if (action == CPU_PM_ENTER_FAILED || action == CPU_PM_EXIT)
+ arch_timer_set_cntkctl(saved_cntkctl);
+ return NOTIFY_OK;
+}
+
+static struct notifier_block arch_timer_cpu_pm_notifier = {
+ .notifier_call = arch_timer_cpu_pm_notify,
+};
+
+static int __init arch_timer_cpu_pm_init(void)
+{
+ return cpu_pm_register_notifier(&arch_timer_cpu_pm_notifier);
+}
+#else
+static int __init arch_timer_cpu_pm_init(void)
+{
+ return 0;
+}
+#endif
+
static int __init arch_timer_register(void)
{
int err;
@@ -499,11 +546,17 @@ static int __init arch_timer_register(void)
if (err)
goto out_free_irq;
+ err = arch_timer_cpu_pm_init();
+ if (err)
+ goto out_unreg_notify;
+
/* Immediately configure the timer on the boot CPU */
arch_timer_setup(this_cpu_ptr(arch_timer_evt));
return 0;
+out_unreg_notify:
+ unregister_cpu_notifier(&arch_timer_cpu_nb);
out_free_irq:
if (arch_timer_use_virtual)
free_percpu_irq(arch_timer_ppi[VIRT_PPI], arch_timer_evt);