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-rw-r--r--arch/arm/kernel/sched_clock.c24
1 files changed, 24 insertions, 0 deletions
diff --git a/arch/arm/kernel/sched_clock.c b/arch/arm/kernel/sched_clock.c
index 27d186a..f451539 100644
--- a/arch/arm/kernel/sched_clock.c
+++ b/arch/arm/kernel/sched_clock.c
@@ -21,6 +21,8 @@ struct clock_data {
u32 epoch_cyc_copy;
u32 mult;
u32 shift;
+ bool suspended;
+ bool needs_suspend;
};
static void sched_clock_poll(unsigned long wrap_ticks);
@@ -49,6 +51,9 @@ static unsigned long long cyc_to_sched_clock(u32 cyc, u32 mask)
u64 epoch_ns;
u32 epoch_cyc;
+ if (cd.suspended)
+ return cd.epoch_ns;
+
/*
* Load the epoch_cyc and epoch_ns atomically. We do this by
* ensuring that we always write epoch_cyc, epoch_ns and
@@ -98,6 +103,13 @@ static void sched_clock_poll(unsigned long wrap_ticks)
update_sched_clock();
}
+void __init setup_sched_clock_needs_suspend(u32 (*read)(void), int bits,
+ unsigned long rate)
+{
+ setup_sched_clock(read, bits, rate);
+ cd.needs_suspend = true;
+}
+
void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate)
{
unsigned long r, w;
@@ -169,11 +181,23 @@ void __init sched_clock_postinit(void)
static int sched_clock_suspend(void)
{
sched_clock_poll(sched_clock_timer.data);
+ if (cd.needs_suspend)
+ cd.suspended = true;
return 0;
}
+static void sched_clock_resume(void)
+{
+ if (cd.needs_suspend) {
+ cd.epoch_cyc = read_sched_clock();
+ cd.epoch_cyc_copy = cd.epoch_cyc;
+ cd.suspended = false;
+ }
+}
+
static struct syscore_ops sched_clock_ops = {
.suspend = sched_clock_suspend,
+ .resume = sched_clock_resume,
};
static int __init sched_clock_syscore_init(void)