On Tue, Aug 23, 2022 at 04:04:39PM +1000, Jonathan Gray wrote: > On Mon, Aug 22, 2022 at 09:37:02AM -0500, Scott Cheloha wrote: > > On Wed, Aug 17, 2022 at 09:00:12PM +1000, Jonathan Gray wrote: > > > On Wed, Aug 17, 2022 at 04:53:20PM +1000, Jonathan Gray wrote: > > > > > > > > It seems to me it would be cleaner if the decision of what to use for > > > > delay could be moved into an md file. > > > > > > > > Or abstract it by having a numeric weight like timecounters or driver > > > > match return numbers. > > > > > > diff against your previous, does not change lapic_delay > > > > Sorry for the delay. > > > > :) > > > > I was out of town. > > > > I slept on this and you're right, this is better. > > > > Couple tweaks: > > > > - Move the quality numbers into cpu.h and give them names. That way, > > the next time Intel, or AMD, or Microsoft or [...] does something > > foolish we don't need to rototill all these files to juggle the > > quality hierarchy. > > While that would allow arch specific differences, removing one would > require changing at least three places in the tree.
Okay, nevermind. Patch updated below. > > - Update both amd64 and i386's lapic.c to use delay_init(). While we > > have a lapic_delay() in the tree it should cooperate with everything > > else. > > > > - Include <machine/cpu.h> in any files calling delay_init() where it > > isn't already included. > > > > - Give the variables in delay_init() real names. > > hmm > > > I'm unsure about two small things: > > > > - Can i386 use hv_delay()? The i386 GENERIC config does not list > > hyperv(4) support so my guess is "no" and I have excluded > > HV_DELAY_QUALITY from i386's cpu.h. > > > > - If a Hyper-V guest could choose between hv_delay() and > > lapic_delay(), which would be preferable? Right now I > > have hv_delay() scored lower than lapic_delay(). > > Hyper-V generation 1 VMs are bios boot with emulation of the usual > devices. 32-bit and 64-bit guests. > > Hyper-V generation 2 VMs are 64-bit uefi with paravirtualised devices. > 64-bit guests only. > > There is no 8254 in generation 2. > No HPET in either generation. > > hv_delay uses the "Partition Reference Counter MSR" described in > https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/tlfs/timers > It seems it is available in both generations and could be used from i386? > > From reading that page hv_delay() should be preferred over lapic_delay() Alright, I have nudged hv_delay's quality up over lapic_delay's quality. How are we looking now? Index: sys/arch/amd64/amd64/lapic.c =================================================================== RCS file: /cvs/src/sys/arch/amd64/amd64/lapic.c,v retrieving revision 1.60 diff -u -p -r1.60 lapic.c --- sys/arch/amd64/amd64/lapic.c 15 Aug 2022 04:17:50 -0000 1.60 +++ sys/arch/amd64/amd64/lapic.c 23 Aug 2022 17:18:30 -0000 @@ -486,8 +486,6 @@ wait_next_cycle(void) } } -extern void tsc_delay(int); - /* * Calibrate the local apic count-down timer (which is running at * bus-clock speed) vs. the i8254 counter/timer (which is running at @@ -592,8 +590,7 @@ skip_calibration: * Now that the timer's calibrated, use the apic timer routines * for all our timing needs.. */ - if (delay_func == i8254_delay) - delay_func = lapic_delay; + delay_init(lapic_delay, 3000); initclock_func = lapic_initclocks; } } Index: sys/arch/amd64/amd64/machdep.c =================================================================== RCS file: /cvs/src/sys/arch/amd64/amd64/machdep.c,v retrieving revision 1.279 diff -u -p -r1.279 machdep.c --- sys/arch/amd64/amd64/machdep.c 7 Aug 2022 23:56:06 -0000 1.279 +++ sys/arch/amd64/amd64/machdep.c 23 Aug 2022 17:18:31 -0000 @@ -2069,3 +2069,13 @@ check_context(const struct reg *regs, st return 0; } + +void +delay_init(void(*fn)(int), int fn_quality) +{ + static int cur_quality = 0; + if (fn_quality > cur_quality) { + delay_func = fn; + cur_quality = fn_quality; + } +} Index: sys/arch/amd64/amd64/tsc.c =================================================================== RCS file: /cvs/src/sys/arch/amd64/amd64/tsc.c,v retrieving revision 1.25 diff -u -p -r1.25 tsc.c --- sys/arch/amd64/amd64/tsc.c 12 Aug 2022 02:20:36 -0000 1.25 +++ sys/arch/amd64/amd64/tsc.c 23 Aug 2022 17:18:31 -0000 @@ -109,7 +109,7 @@ tsc_identify(struct cpu_info *ci) tsc_frequency = tsc_freq_cpuid(ci); if (tsc_frequency > 0) - delay_func = tsc_delay; + delay_init(tsc_delay, 5000); } static inline int Index: sys/arch/amd64/include/cpu.h =================================================================== RCS file: /cvs/src/sys/arch/amd64/include/cpu.h,v retrieving revision 1.148 diff -u -p -r1.148 cpu.h --- sys/arch/amd64/include/cpu.h 22 Aug 2022 08:57:54 -0000 1.148 +++ sys/arch/amd64/include/cpu.h 23 Aug 2022 17:18:31 -0000 @@ -359,6 +359,7 @@ void signotify(struct proc *); * We need a machine-independent name for this. */ extern void (*delay_func)(int); +void delay_init(void (*)(int), int); struct timeval; #define DELAY(x) (*delay_func)(x) Index: sys/arch/i386/i386/lapic.c =================================================================== RCS file: /cvs/src/sys/arch/i386/i386/lapic.c,v retrieving revision 1.49 diff -u -p -r1.49 lapic.c --- sys/arch/i386/i386/lapic.c 15 Aug 2022 04:17:50 -0000 1.49 +++ sys/arch/i386/i386/lapic.c 23 Aug 2022 17:18:31 -0000 @@ -395,7 +395,7 @@ lapic_calibrate_timer(struct cpu_info *c * Now that the timer's calibrated, use the apic timer routines * for all our timing needs.. */ - delay_func = lapic_delay; + delay_init(lapic_delay, 3000); initclock_func = lapic_initclocks; } } Index: sys/arch/i386/i386/machdep.c =================================================================== RCS file: /cvs/src/sys/arch/i386/i386/machdep.c,v retrieving revision 1.655 diff -u -p -r1.655 machdep.c --- sys/arch/i386/i386/machdep.c 22 Aug 2022 08:53:55 -0000 1.655 +++ sys/arch/i386/i386/machdep.c 23 Aug 2022 17:18:33 -0000 @@ -3974,3 +3974,13 @@ cpu_rnd_messybits(void) nanotime(&ts); return (ts.tv_nsec ^ (ts.tv_sec << 20)); } + +void +delay_init(void(*fn)(int), int fn_quality) +{ + static int cur_quality = 0; + if (fn_quality > cur_quality) { + delay_func = fn; + cur_quality = fn_quality; + } +} Index: sys/arch/i386/include/cpu.h =================================================================== RCS file: /cvs/src/sys/arch/i386/include/cpu.h,v retrieving revision 1.177 diff -u -p -r1.177 cpu.h --- sys/arch/i386/include/cpu.h 22 Aug 2022 08:53:55 -0000 1.177 +++ sys/arch/i386/include/cpu.h 23 Aug 2022 17:18:33 -0000 @@ -302,6 +302,7 @@ void signotify(struct proc *); * We need a machine-independent name for this. */ extern void (*delay_func)(int); +void delay_init(void(*)(int), int); struct timeval; #define DELAY(x) (*delay_func)(x) Index: sys/dev/acpi/acpitimer.c =================================================================== RCS file: /cvs/src/sys/dev/acpi/acpitimer.c,v retrieving revision 1.15 diff -u -p -r1.15 acpitimer.c --- sys/dev/acpi/acpitimer.c 6 Apr 2022 18:59:27 -0000 1.15 +++ sys/dev/acpi/acpitimer.c 23 Aug 2022 17:18:33 -0000 @@ -18,17 +18,22 @@ #include <sys/param.h> #include <sys/systm.h> #include <sys/device.h> +#include <sys/stdint.h> #include <sys/timetc.h> #include <machine/bus.h> +#include <machine/cpu.h> #include <dev/acpi/acpireg.h> #include <dev/acpi/acpivar.h> +struct acpitimer_softc; + int acpitimermatch(struct device *, void *, void *); void acpitimerattach(struct device *, struct device *, void *); - +void acpitimer_delay(int); u_int acpi_get_timecount(struct timecounter *tc); +uint32_t acpitimer_read(struct acpitimer_softc *); static struct timecounter acpi_timecounter = { .tc_get_timecount = acpi_get_timecount, @@ -98,18 +103,43 @@ acpitimerattach(struct device *parent, s acpi_timecounter.tc_priv = sc; acpi_timecounter.tc_name = sc->sc_dev.dv_xname; tc_init(&acpi_timecounter); + + delay_init(acpitimer_delay, 1000); + #if defined(__amd64__) extern void cpu_recalibrate_tsc(struct timecounter *); cpu_recalibrate_tsc(&acpi_timecounter); #endif } +void +acpitimer_delay(int usecs) +{ + uint64_t count = 0, cycles; + struct acpitimer_softc *sc = acpi_timecounter.tc_priv; + uint32_t mask = acpi_timecounter.tc_counter_mask; + uint32_t val1, val2; + + val2 = acpitimer_read(sc); + cycles = usecs * acpi_timecounter.tc_frequency / 1000000; + while (count < cycles) { + CPU_BUSY_CYCLE(); + val1 = val2; + val2 = acpitimer_read(sc); + count += (val2 - val1) & mask; + } +} u_int acpi_get_timecount(struct timecounter *tc) { - struct acpitimer_softc *sc = tc->tc_priv; - u_int u1, u2, u3; + return acpitimer_read(tc->tc_priv); +} + +uint32_t +acpitimer_read(struct acpitimer_softc *sc) +{ + uint32_t u1, u2, u3; u2 = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 0); u3 = bus_space_read_4(sc->sc_iot, sc->sc_ioh, 0); Index: sys/dev/acpi/acpihpet.c =================================================================== RCS file: /cvs/src/sys/dev/acpi/acpihpet.c,v retrieving revision 1.26 diff -u -p -r1.26 acpihpet.c --- sys/dev/acpi/acpihpet.c 6 Apr 2022 18:59:27 -0000 1.26 +++ sys/dev/acpi/acpihpet.c 23 Aug 2022 17:18:33 -0000 @@ -18,9 +18,11 @@ #include <sys/param.h> #include <sys/systm.h> #include <sys/device.h> +#include <sys/stdint.h> #include <sys/timetc.h> #include <machine/bus.h> +#include <machine/cpu.h> #include <dev/acpi/acpireg.h> #include <dev/acpi/acpivar.h> @@ -31,7 +33,7 @@ int acpihpet_attached; int acpihpet_match(struct device *, void *, void *); void acpihpet_attach(struct device *, struct device *, void *); int acpihpet_activate(struct device *, int); - +void acpihpet_delay(int); u_int acpihpet_gettime(struct timecounter *tc); uint64_t acpihpet_r(bus_space_tag_t _iot, bus_space_handle_t _ioh, @@ -262,15 +264,30 @@ acpihpet_attach(struct device *parent, s freq = 1000000000000000ull / period; printf(": %lld Hz\n", freq); - hpet_timecounter.tc_frequency = (uint32_t)freq; + hpet_timecounter.tc_frequency = freq; hpet_timecounter.tc_priv = sc; hpet_timecounter.tc_name = sc->sc_dev.dv_xname; tc_init(&hpet_timecounter); + + delay_init(acpihpet_delay, 2000); + #if defined(__amd64__) extern void cpu_recalibrate_tsc(struct timecounter *); cpu_recalibrate_tsc(&hpet_timecounter); #endif acpihpet_attached++; +} + +void +acpihpet_delay(int usecs) +{ + uint64_t c, s; + struct acpihpet_softc *sc = hpet_timecounter.tc_priv; + + s = acpihpet_r(sc->sc_iot, sc->sc_ioh, HPET_MAIN_COUNTER); + c = usecs * hpet_timecounter.tc_frequency / 1000000; + while (acpihpet_r(sc->sc_iot, sc->sc_ioh, HPET_MAIN_COUNTER) - s < c) + CPU_BUSY_CYCLE(); } u_int Index: sys/dev/pv/pvbus.c =================================================================== RCS file: /cvs/src/sys/dev/pv/pvbus.c,v retrieving revision 1.24 diff -u -p -r1.24 pvbus.c --- sys/dev/pv/pvbus.c 5 Nov 2021 11:38:29 -0000 1.24 +++ sys/dev/pv/pvbus.c 23 Aug 2022 17:18:33 -0000 @@ -319,9 +319,8 @@ pvbus_hyperv(struct pvbus_hv *hv) HYPERV_VERSION_EBX_MINOR_S; #if NHYPERV > 0 - if (hv->hv_features & CPUID_HV_MSR_TIME_REFCNT && - delay_func == i8254_delay) - delay_func = hv_delay; + if (hv->hv_features & CPUID_HV_MSR_TIME_REFCNT) + delay_init(hv_delay, 4000); #endif }
