diff options
Diffstat (limited to 'arch/parisc/kernel/time.c')
| -rw-r--r-- | arch/parisc/kernel/time.c | 57 |
1 files changed, 11 insertions, 46 deletions
diff --git a/arch/parisc/kernel/time.c b/arch/parisc/kernel/time.c index 9b63b876a13a..325f30d82b64 100644 --- a/arch/parisc/kernel/time.c +++ b/arch/parisc/kernel/time.c @@ -14,6 +14,7 @@ #include <linux/module.h> #include <linux/rtc.h> #include <linux/sched.h> +#include <linux/sched_clock.h> #include <linux/kernel.h> #include <linux/param.h> #include <linux/string.h> @@ -39,18 +40,6 @@ static unsigned long clocktick __read_mostly; /* timer cycles per tick */ -#ifndef CONFIG_64BIT -/* - * The processor-internal cycle counter (Control Register 16) is used as time - * source for the sched_clock() function. This register is 64bit wide on a - * 64-bit kernel and 32bit on a 32-bit kernel. Since sched_clock() always - * requires a 64bit counter we emulate on the 32-bit kernel the higher 32bits - * with a per-cpu variable which we increase every time the counter - * wraps-around (which happens every ~4 secounds). - */ -static DEFINE_PER_CPU(unsigned long, cr16_high_32_bits); -#endif - /* * We keep time on PA-RISC Linux by using the Interval Timer which is * a pair of registers; one is read-only and one is write-only; both @@ -121,12 +110,6 @@ irqreturn_t __irq_entry timer_interrupt(int irq, void *dev_id) */ mtctl(next_tick, 16); -#if !defined(CONFIG_64BIT) - /* check for overflow on a 32bit kernel (every ~4 seconds). */ - if (unlikely(next_tick < now)) - this_cpu_inc(cr16_high_32_bits); -#endif - /* Skip one clocktick on purpose if we missed next_tick. * The new CR16 must be "later" than current CR16 otherwise * itimer would not fire until CR16 wrapped - e.g 4 seconds @@ -208,7 +191,7 @@ EXPORT_SYMBOL(profile_pc); /* clock source code */ -static cycle_t read_cr16(struct clocksource *cs) +static cycle_t notrace read_cr16(struct clocksource *cs) { return get_cycles(); } @@ -287,26 +270,9 @@ void read_persistent_clock(struct timespec *ts) } -/* - * sched_clock() framework - */ - -static u32 cyc2ns_mul __read_mostly; -static u32 cyc2ns_shift __read_mostly; - -u64 sched_clock(void) +static u64 notrace read_cr16_sched_clock(void) { - u64 now; - - /* Get current cycle counter (Control Register 16). */ -#ifdef CONFIG_64BIT - now = mfctl(16); -#else - now = mfctl(16) + (((u64) this_cpu_read(cr16_high_32_bits)) << 32); -#endif - - /* return the value in ns (cycles_2_ns) */ - return mul_u64_u32_shr(now, cyc2ns_mul, cyc2ns_shift); + return get_cycles(); } @@ -316,17 +282,16 @@ u64 sched_clock(void) void __init time_init(void) { - unsigned long current_cr16_khz; + unsigned long cr16_hz; - current_cr16_khz = PAGE0->mem_10msec/10; /* kHz */ clocktick = (100 * PAGE0->mem_10msec) / HZ; - - /* calculate mult/shift values for cr16 */ - clocks_calc_mult_shift(&cyc2ns_mul, &cyc2ns_shift, current_cr16_khz, - NSEC_PER_MSEC, 0); - start_cpu_itimer(); /* get CPU 0 started */ + cr16_hz = 100 * PAGE0->mem_10msec; /* Hz */ + /* register at clocksource framework */ - clocksource_register_khz(&clocksource_cr16, current_cr16_khz); + clocksource_register_hz(&clocksource_cr16, cr16_hz); + + /* register as sched_clock source */ + sched_clock_register(read_cr16_sched_clock, BITS_PER_LONG, cr16_hz); } |