diff options
Diffstat (limited to 'arch/arm/kernel/sched_clock.c')
| -rw-r--r-- | arch/arm/kernel/sched_clock.c | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/arch/arm/kernel/sched_clock.c b/arch/arm/kernel/sched_clock.c index bd6f56b9ec2..e8edcaa0e43 100644 --- a/arch/arm/kernel/sched_clock.c +++ b/arch/arm/kernel/sched_clock.c @@ -20,6 +20,7 @@ struct clock_data { u64 epoch_ns; u32 epoch_cyc; u32 epoch_cyc_copy; + unsigned long rate; u32 mult; u32 shift; bool suspended; @@ -45,12 +46,12 @@ static u32 notrace jiffy_sched_clock_read(void) static u32 __read_mostly (*read_sched_clock)(void) = jiffy_sched_clock_read; -static inline u64 cyc_to_ns(u64 cyc, u32 mult, u32 shift) +static inline u64 notrace cyc_to_ns(u64 cyc, u32 mult, u32 shift) { return (cyc * mult) >> shift; } -static unsigned long long cyc_to_sched_clock(u32 cyc, u32 mask) +static unsigned long long notrace cyc_to_sched_clock(u32 cyc, u32 mask) { u64 epoch_ns; u32 epoch_cyc; @@ -113,11 +114,14 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate) u64 res, wrap; char r_unit; + if (cd.rate > rate) + return; + BUG_ON(bits > 32); WARN_ON(!irqs_disabled()); - WARN_ON(read_sched_clock != jiffy_sched_clock_read); read_sched_clock = read; sched_clock_mask = (1 << bits) - 1; + cd.rate = rate; /* calculate the mult/shift to convert counter ticks to ns. */ clocks_calc_mult_shift(&cd.mult, &cd.shift, rate, NSEC_PER_SEC, 0); @@ -161,12 +165,19 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate) pr_debug("Registered %pF as sched_clock source\n", read); } -unsigned long long notrace sched_clock(void) +static unsigned long long notrace sched_clock_32(void) { u32 cyc = read_sched_clock(); return cyc_to_sched_clock(cyc, sched_clock_mask); } +unsigned long long __read_mostly (*sched_clock_func)(void) = sched_clock_32; + +unsigned long long notrace sched_clock(void) +{ + return sched_clock_func(); +} + void __init sched_clock_postinit(void) { /* |