From 18cf9b3a01f8ab59565d0be09a919922c195da48 Mon Sep 17 00:00:00 2001 From: cheloha Date: Tue, 17 Jan 2023 02:58:22 +0000 Subject: [PATCH] agtimer(4/armv7): switch to clockintr - Strip out custom hardclock/statclock scheduling code. - Remove debug evcount code. We can no longer differentiate between hardclock and statclock in the driver. - Wire up agtimer_intrclock. With tweaks from miod@ and jca@. Tested by jca@ and kettenis@. Link: https://marc.info/?l=openbsd-tech&m=167044965011140&w=2 ok kettenis@ --- sys/arch/arm/cortex/agtimer.c | 183 ++++++++++------------------------ 1 file changed, 55 insertions(+), 128 deletions(-) diff --git a/sys/arch/arm/cortex/agtimer.c b/sys/arch/arm/cortex/agtimer.c index 6b5505fb586..77ecfbb2e92 100644 --- a/sys/arch/arm/cortex/agtimer.c +++ b/sys/arch/arm/cortex/agtimer.c @@ -1,4 +1,4 @@ -/* $OpenBSD: agtimer.c,v 1.15 2022/03/12 14:40:41 mpi Exp $ */ +/* $OpenBSD: agtimer.c,v 1.16 2023/01/17 02:58:22 cheloha Exp $ */ /* * Copyright (c) 2011 Dale Rahn * Copyright (c) 2013 Patrick Wildt @@ -18,8 +18,10 @@ #include #include +#include #include #include +#include #include #include @@ -51,28 +53,12 @@ static struct timecounter agtimer_timecounter = { .tc_priv = NULL, }; -struct agtimer_pcpu_softc { - uint64_t pc_nexttickevent; - uint64_t pc_nextstatevent; - u_int32_t pc_ticks_err_sum; -}; - struct agtimer_softc { struct device sc_dev; int sc_node; - - struct agtimer_pcpu_softc sc_pstat[MAXCPUS]; - - u_int32_t sc_ticks_err_cnt; u_int32_t sc_ticks_per_second; - u_int32_t sc_ticks_per_intr; - u_int32_t sc_statvar; - u_int32_t sc_statmin; - -#ifdef AMPTIMER_DEBUG - struct evcount sc_clk_count; - struct evcount sc_stat_count; -#endif + uint64_t sc_nsec_cycle_ratio; + uint64_t sc_nsec_max; }; int agtimer_match(struct device *, void *, void *); @@ -93,6 +79,14 @@ struct cfdriver agtimer_cd = { NULL, "agtimer", DV_DULL }; +void agtimer_rearm(void *, uint64_t); +void agtimer_trigger(void *); + +struct intrclock agtimer_intrclock = { + .ic_rearm = agtimer_rearm, + .ic_trigger = agtimer_trigger +}; + uint64_t agtimer_readcnt64(void) { @@ -155,16 +149,13 @@ agtimer_attach(struct device *parent, struct device *self, void *aux) agtimer_frequency = OF_getpropint(sc->sc_node, "clock-frequency", agtimer_frequency); sc->sc_ticks_per_second = agtimer_frequency; - + sc->sc_nsec_cycle_ratio = + sc->sc_ticks_per_second * (1ULL << 32) / 1000000000; + sc->sc_nsec_max = UINT64_MAX / sc->sc_nsec_cycle_ratio; printf(": %d kHz\n", sc->sc_ticks_per_second / 1000); /* XXX: disable user access */ -#ifdef AMPTIMER_DEBUG - evcount_attach(&sc->sc_clk_count, "clock", NULL); - evcount_attach(&sc->sc_stat_count, "stat", NULL); -#endif - /* * private timer and interrupts not enabled until * timer configures @@ -175,8 +166,9 @@ agtimer_attach(struct device *parent, struct device *self, void *aux) agtimer_timecounter.tc_frequency = sc->sc_ticks_per_second; agtimer_timecounter.tc_priv = sc; - tc_init(&agtimer_timecounter); + + agtimer_intrclock.ic_cookie = sc; } u_int @@ -185,72 +177,30 @@ agtimer_get_timecount(struct timecounter *tc) return agtimer_readcnt64(); } -int -agtimer_intr(void *frame) +void +agtimer_rearm(void *cookie, uint64_t nsecs) { - struct agtimer_softc *sc = agtimer_cd.cd_devs[0]; - struct agtimer_pcpu_softc *pc = &sc->sc_pstat[CPU_INFO_UNIT(curcpu())]; - uint64_t now; - uint64_t nextevent; - uint32_t r; -#if defined(USE_GTIMER_CMP) - int skip = 1; -#else - int64_t delay; -#endif - int rc = 0; - - /* - * DSR - I know that the tick timer is 64 bits, but the following - * code deals with rollover, so there is no point in dealing - * with the 64 bit math, just let the 32 bit rollover - * do the right thing - */ - - now = agtimer_readcnt64(); - - while (pc->pc_nexttickevent <= now) { - pc->pc_nexttickevent += sc->sc_ticks_per_intr; - pc->pc_ticks_err_sum += sc->sc_ticks_err_cnt; - - /* looping a few times is faster than divide */ - while (pc->pc_ticks_err_sum > hz) { - pc->pc_nexttickevent += 1; - pc->pc_ticks_err_sum -= hz; - } - -#ifdef AMPTIMER_DEBUG - sc->sc_clk_count.ec_count++; -#endif - rc = 1; - hardclock(frame); - } - while (pc->pc_nextstatevent <= now) { - do { - r = random() & (sc->sc_statvar -1); - } while (r == 0); /* random == 0 not allowed */ - pc->pc_nextstatevent += sc->sc_statmin + r; - - /* XXX - correct nextstatevent? */ -#ifdef AMPTIMER_DEBUG - sc->sc_stat_count.ec_count++; -#endif - rc = 1; - statclock(frame); - } - - if (pc->pc_nexttickevent < pc->pc_nextstatevent) - nextevent = pc->pc_nexttickevent; - else - nextevent = pc->pc_nextstatevent; - - delay = nextevent - now; - if (delay < 0) - delay = 1; + struct agtimer_softc *sc = cookie; + uint32_t cycles; + + if (nsecs > sc->sc_nsec_max) + nsecs = sc->sc_nsec_max; + cycles = (nsecs * sc->sc_nsec_cycle_ratio) >> 32; + if (cycles > INT32_MAX) + cycles = INT32_MAX; + agtimer_set_tval(cycles); +} - agtimer_set_tval(delay); +void +agtimer_trigger(void *unused) +{ + agtimer_set_tval(0); +} - return (rc); +int +agtimer_intr(void *frame) +{ + return clockintr_dispatch(frame); } void @@ -264,7 +214,12 @@ agtimer_set_clockrate(int32_t new_frequency) return; sc->sc_ticks_per_second = agtimer_frequency; + sc->sc_nsec_cycle_ratio = + sc->sc_ticks_per_second * (1ULL << 32) / 1000000000; + sc->sc_nsec_max = UINT64_MAX / sc->sc_nsec_cycle_ratio; + agtimer_timecounter.tc_frequency = sc->sc_ticks_per_second; + printf("agtimer0: adjusting clock: new rate %d kHz\n", sc->sc_ticks_per_second / 1000); } @@ -273,22 +228,17 @@ void agtimer_cpu_initclocks(void) { struct agtimer_softc *sc = agtimer_cd.cd_devs[0]; - struct agtimer_pcpu_softc *pc = &sc->sc_pstat[CPU_INFO_UNIT(curcpu())]; uint32_t reg; - uint64_t next; stathz = hz; - profhz = hz * 10; + profhz = stathz * 10; + clockintr_init(CL_RNDSTAT); if (sc->sc_ticks_per_second != agtimer_frequency) { agtimer_set_clockrate(agtimer_frequency); } - agtimer_setstatclockrate(stathz); - - sc->sc_ticks_per_intr = sc->sc_ticks_per_second / hz; - sc->sc_ticks_err_cnt = sc->sc_ticks_per_second % hz; - pc->pc_ticks_err_sum = 0; + clockintr_cpu_init(&agtimer_intrclock); /* Setup secure and non-secure timer IRQs. */ arm_intr_establish_fdt_idx(sc->sc_node, 0, IPL_CLOCK, @@ -296,14 +246,13 @@ agtimer_cpu_initclocks(void) arm_intr_establish_fdt_idx(sc->sc_node, 1, IPL_CLOCK, agtimer_intr, NULL, "tick"); - next = agtimer_readcnt64() + sc->sc_ticks_per_intr; - pc->pc_nexttickevent = pc->pc_nextstatevent = next; - reg = agtimer_get_ctrl(); reg &= ~GTIMER_CNTP_CTL_IMASK; reg |= GTIMER_CNTP_CTL_ENABLE; - agtimer_set_tval(sc->sc_ticks_per_second); + agtimer_set_tval(INT32_MAX); agtimer_set_ctrl(reg); + + clockintr_trigger(); } void @@ -340,45 +289,23 @@ agtimer_delay(u_int usecs) void agtimer_setstatclockrate(int newhz) { - struct agtimer_softc *sc = agtimer_cd.cd_devs[0]; - int minint, statint; - int s; - - s = splclock(); - - statint = sc->sc_ticks_per_second / newhz; - /* calculate largest 2^n which is smaller that just over half statint */ - sc->sc_statvar = 0x40000000; /* really big power of two */ - minint = statint / 2 + 100; - while (sc->sc_statvar > minint) - sc->sc_statvar >>= 1; - - sc->sc_statmin = statint - (sc->sc_statvar >> 1); - - splx(s); - - /* - * XXX this allows the next stat timer to occur then it switches - * to the new frequency. Rather than switching instantly. - */ + clockintr_setstatclockrate(newhz); } void agtimer_startclock(void) { - struct agtimer_softc *sc = agtimer_cd.cd_devs[0]; - struct agtimer_pcpu_softc *pc = &sc->sc_pstat[CPU_INFO_UNIT(curcpu())]; - uint64_t nextevent; uint32_t reg; - nextevent = agtimer_readcnt64() + sc->sc_ticks_per_intr; - pc->pc_nexttickevent = pc->pc_nextstatevent = nextevent; + clockintr_cpu_init(&agtimer_intrclock); reg = agtimer_get_ctrl(); reg &= ~GTIMER_CNTP_CTL_IMASK; reg |= GTIMER_CNTP_CTL_ENABLE; - agtimer_set_tval(sc->sc_ticks_per_second); + agtimer_set_tval(INT32_MAX); agtimer_set_ctrl(reg); + + clockintr_trigger(); } void -- 2.20.1