diff options
Diffstat (limited to 'arch/arm/kernel/sched_clock.c')
| -rw-r--r-- | arch/arm/kernel/sched_clock.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/arch/arm/kernel/sched_clock.c b/arch/arm/kernel/sched_clock.c index 27d186abbc06..e21bac20d90d 100644 --- a/arch/arm/kernel/sched_clock.c +++ b/arch/arm/kernel/sched_clock.c @@ -9,6 +9,7 @@ #include <linux/init.h> #include <linux/jiffies.h> #include <linux/kernel.h> +#include <linux/moduleparam.h> #include <linux/sched.h> #include <linux/syscore_ops.h> #include <linux/timer.h> @@ -21,10 +22,15 @@ 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); static DEFINE_TIMER(sched_clock_timer, sched_clock_poll, 0, 0); +static int irqtime = -1; + +core_param(irqtime, irqtime, int, 0400); static struct clock_data cd = { .mult = NSEC_PER_SEC / HZ, @@ -49,6 +55,9 @@ 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 +107,13 @@ 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; @@ -145,6 +161,10 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate) */ cd.epoch_ns = 0; + /* Enable IRQ time accounting if we have a fast enough sched_clock */ + if (irqtime > 0 || (irqtime == -1 && rate >= 1000000)) + enable_sched_clock_irqtime(); + pr_debug("Registered %pF as sched_clock source\n", read); } @@ -169,11 +189,23 @@ 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) |