diff options
Diffstat (limited to 'arch/tile/kernel/time.c')
| -rw-r--r-- | arch/tile/kernel/time.c | 306 |
1 files changed, 0 insertions, 306 deletions
diff --git a/arch/tile/kernel/time.c b/arch/tile/kernel/time.c deleted file mode 100644 index f95d65f3162b..000000000000 --- a/arch/tile/kernel/time.c +++ /dev/null @@ -1,306 +0,0 @@ -/* - * Copyright 2010 Tilera Corporation. All Rights Reserved. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation, version 2. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or - * NON INFRINGEMENT. See the GNU General Public License for - * more details. - * - * Support the cycle counter clocksource and tile timer clock event device. - */ - -#include <linux/time.h> -#include <linux/timex.h> -#include <linux/clocksource.h> -#include <linux/clockchips.h> -#include <linux/hardirq.h> -#include <linux/sched.h> -#include <linux/sched/clock.h> -#include <linux/smp.h> -#include <linux/delay.h> -#include <linux/module.h> -#include <linux/timekeeper_internal.h> -#include <asm/irq_regs.h> -#include <asm/traps.h> -#include <asm/vdso.h> -#include <hv/hypervisor.h> -#include <arch/interrupts.h> -#include <arch/spr_def.h> - - -/* - * Define the cycle counter clock source. - */ - -/* How many cycles per second we are running at. */ -static cycles_t cycles_per_sec __ro_after_init; - -cycles_t get_clock_rate(void) -{ - return cycles_per_sec; -} - -#if CHIP_HAS_SPLIT_CYCLE() -cycles_t get_cycles(void) -{ - unsigned int high = __insn_mfspr(SPR_CYCLE_HIGH); - unsigned int low = __insn_mfspr(SPR_CYCLE_LOW); - unsigned int high2 = __insn_mfspr(SPR_CYCLE_HIGH); - - while (unlikely(high != high2)) { - low = __insn_mfspr(SPR_CYCLE_LOW); - high = high2; - high2 = __insn_mfspr(SPR_CYCLE_HIGH); - } - - return (((cycles_t)high) << 32) | low; -} -EXPORT_SYMBOL(get_cycles); -#endif - -/* - * We use a relatively small shift value so that sched_clock() - * won't wrap around very often. - */ -#define SCHED_CLOCK_SHIFT 10 - -static unsigned long sched_clock_mult __ro_after_init; - -static cycles_t clocksource_get_cycles(struct clocksource *cs) -{ - return get_cycles(); -} - -static struct clocksource cycle_counter_cs = { - .name = "cycle counter", - .rating = 300, - .read = clocksource_get_cycles, - .mask = CLOCKSOURCE_MASK(64), - .flags = CLOCK_SOURCE_IS_CONTINUOUS, -}; - -/* - * Called very early from setup_arch() to set cycles_per_sec. - * We initialize it early so we can use it to set up loops_per_jiffy. - */ -void __init setup_clock(void) -{ - cycles_per_sec = hv_sysconf(HV_SYSCONF_CPU_SPEED); - sched_clock_mult = - clocksource_hz2mult(cycles_per_sec, SCHED_CLOCK_SHIFT); -} - -void __init calibrate_delay(void) -{ - loops_per_jiffy = get_clock_rate() / HZ; - pr_info("Clock rate yields %lu.%02lu BogoMIPS (lpj=%lu)\n", - loops_per_jiffy / (500000 / HZ), - (loops_per_jiffy / (5000 / HZ)) % 100, loops_per_jiffy); -} - -/* Called fairly late in init/main.c, but before we go smp. */ -void __init time_init(void) -{ - /* Initialize and register the clock source. */ - clocksource_register_hz(&cycle_counter_cs, cycles_per_sec); - - /* Start up the tile-timer interrupt source on the boot cpu. */ - setup_tile_timer(); -} - -/* - * Define the tile timer clock event device. The timer is driven by - * the TILE_TIMER_CONTROL register, which consists of a 31-bit down - * counter, plus bit 31, which signifies that the counter has wrapped - * from zero to (2**31) - 1. The INT_TILE_TIMER interrupt will be - * raised as long as bit 31 is set. - * - * The TILE_MINSEC value represents the largest range of real-time - * we can possibly cover with the timer, based on MAX_TICK combined - * with the slowest reasonable clock rate we might run at. - */ - -#define MAX_TICK 0x7fffffff /* we have 31 bits of countdown timer */ -#define TILE_MINSEC 5 /* timer covers no more than 5 seconds */ - -static int tile_timer_set_next_event(unsigned long ticks, - struct clock_event_device *evt) -{ - BUG_ON(ticks > MAX_TICK); - __insn_mtspr(SPR_TILE_TIMER_CONTROL, ticks); - arch_local_irq_unmask_now(INT_TILE_TIMER); - return 0; -} - -/* - * Whenever anyone tries to change modes, we just mask interrupts - * and wait for the next event to get set. - */ -static int tile_timer_shutdown(struct clock_event_device *evt) -{ - arch_local_irq_mask_now(INT_TILE_TIMER); - return 0; -} - -/* - * Set min_delta_ns to 1 microsecond, since it takes about - * that long to fire the interrupt. - */ -static DEFINE_PER_CPU(struct clock_event_device, tile_timer) = { - .name = "tile timer", - .features = CLOCK_EVT_FEAT_ONESHOT, - .min_delta_ns = 1000, - .min_delta_ticks = 1, - .max_delta_ticks = MAX_TICK, - .rating = 100, - .irq = -1, - .set_next_event = tile_timer_set_next_event, - .set_state_shutdown = tile_timer_shutdown, - .set_state_oneshot = tile_timer_shutdown, - .set_state_oneshot_stopped = tile_timer_shutdown, - .tick_resume = tile_timer_shutdown, -}; - -void setup_tile_timer(void) -{ - struct clock_event_device *evt = this_cpu_ptr(&tile_timer); - - /* Fill in fields that are speed-specific. */ - clockevents_calc_mult_shift(evt, cycles_per_sec, TILE_MINSEC); - evt->max_delta_ns = clockevent_delta2ns(MAX_TICK, evt); - - /* Mark as being for this cpu only. */ - evt->cpumask = cpumask_of(smp_processor_id()); - - /* Start out with timer not firing. */ - arch_local_irq_mask_now(INT_TILE_TIMER); - - /* Register tile timer. */ - clockevents_register_device(evt); -} - -/* Called from the interrupt vector. */ -void do_timer_interrupt(struct pt_regs *regs, int fault_num) -{ - struct pt_regs *old_regs = set_irq_regs(regs); - struct clock_event_device *evt = this_cpu_ptr(&tile_timer); - - /* - * Mask the timer interrupt here, since we are a oneshot timer - * and there are now by definition no events pending. - */ - arch_local_irq_mask(INT_TILE_TIMER); - - /* Track time spent here in an interrupt context */ - irq_enter(); - - /* Track interrupt count. */ - __this_cpu_inc(irq_stat.irq_timer_count); - - /* Call the generic timer handler */ - evt->event_handler(evt); - - /* - * Track time spent against the current process again and - * process any softirqs if they are waiting. - */ - irq_exit(); - - set_irq_regs(old_regs); -} - -/* - * Scheduler clock - returns current time in nanosec units. - * Note that with LOCKDEP, this is called during lockdep_init(), and - * we will claim that sched_clock() is zero for a little while, until - * we run setup_clock(), above. - */ -unsigned long long sched_clock(void) -{ - return mult_frac(get_cycles(), - sched_clock_mult, 1ULL << SCHED_CLOCK_SHIFT); -} - -int setup_profiling_timer(unsigned int multiplier) -{ - return -EINVAL; -} - -/* - * Use the tile timer to convert nsecs to core clock cycles, relying - * on it having the same frequency as SPR_CYCLE. - */ -cycles_t ns2cycles(unsigned long nsecs) -{ - /* - * We do not have to disable preemption here as each core has the same - * clock frequency. - */ - struct clock_event_device *dev = raw_cpu_ptr(&tile_timer); - - /* - * as in clocksource.h and x86's timer.h, we split the calculation - * into 2 parts to avoid unecessary overflow of the intermediate - * value. This will not lead to any loss of precision. - */ - u64 quot = (u64)nsecs >> dev->shift; - u64 rem = (u64)nsecs & ((1ULL << dev->shift) - 1); - return quot * dev->mult + ((rem * dev->mult) >> dev->shift); -} - -void update_vsyscall_tz(void) -{ - write_seqcount_begin(&vdso_data->tz_seq); - vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; - vdso_data->tz_dsttime = sys_tz.tz_dsttime; - write_seqcount_end(&vdso_data->tz_seq); -} - -void update_vsyscall(struct timekeeper *tk) -{ - if (tk->tkr_mono.clock != &cycle_counter_cs) - return; - - write_seqcount_begin(&vdso_data->tb_seq); - - vdso_data->cycle_last = tk->tkr_mono.cycle_last; - vdso_data->mask = tk->tkr_mono.mask; - vdso_data->mult = tk->tkr_mono.mult; - vdso_data->shift = tk->tkr_mono.shift; - - vdso_data->wall_time_sec = tk->xtime_sec; - vdso_data->wall_time_snsec = tk->tkr_mono.xtime_nsec; - - vdso_data->monotonic_time_sec = tk->xtime_sec - + tk->wall_to_monotonic.tv_sec; - vdso_data->monotonic_time_snsec = tk->tkr_mono.xtime_nsec - + ((u64)tk->wall_to_monotonic.tv_nsec - << tk->tkr_mono.shift); - while (vdso_data->monotonic_time_snsec >= - (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) { - vdso_data->monotonic_time_snsec -= - ((u64)NSEC_PER_SEC) << tk->tkr_mono.shift; - vdso_data->monotonic_time_sec++; - } - - vdso_data->wall_time_coarse_sec = tk->xtime_sec; - vdso_data->wall_time_coarse_nsec = (long)(tk->tkr_mono.xtime_nsec >> - tk->tkr_mono.shift); - - vdso_data->monotonic_time_coarse_sec = - vdso_data->wall_time_coarse_sec + tk->wall_to_monotonic.tv_sec; - vdso_data->monotonic_time_coarse_nsec = - vdso_data->wall_time_coarse_nsec + tk->wall_to_monotonic.tv_nsec; - - while (vdso_data->monotonic_time_coarse_nsec >= NSEC_PER_SEC) { - vdso_data->monotonic_time_coarse_nsec -= NSEC_PER_SEC; - vdso_data->monotonic_time_coarse_sec++; - } - - write_seqcount_end(&vdso_data->tb_seq); -} |