all platforms: separate cpu_initclocks() from cpu_startclock()

To give the primary CPU an opportunity to perform clock interrupt
preparation in a machine-independent manner we need to separate the
"

all platforms: separate cpu_initclocks() from cpu_startclock()

To give the primary CPU an opportunity to perform clock interrupt
preparation in a machine-independent manner we need to separate the
"initialization" parts of cpu_initclocks() from the "start the clock
interrupt" parts. Currently, cpu_initclocks() does everything all at
once, so there is no space for this MI setup.

Many platforms have more-or-less already done this separation by
implementing a separate routine named "cpu_startclock()". This patch
promotes cpu_startclock() from de facto standard to mandatory API.

- Prototype cpu_startclock() in sys/systm.h alongside cpu_initclocks().
The separation of responsibility between the two routines is a bit
fuzzy but the basic guidelines are as follows:

+ cpu_initclocks() must initialize hz, stathz, and profhz, and call
clockintr_init().

+ cpu_startclock() must call clockintr_cpu_init() and start the clock
interrupt cycle on the calling CPU.

These guidelines will shift in the future, but that's the way things
stand as of *this* commit.

- In initclocks(): first call cpu_initclocks(), then do MI setup, and
last call cpu_startclock().

- On platforms where cpu_startclock() already exists: don't call
cpu_startclock() from cpu_initclocks() anymore.

- On platforms where cpu_startclock() doesn't yet exist: implement it.
Usually this is as simple as dividing cpu_initclocks() in two.

Tested on amd64 (i8254, lapic), arm64, i386 (i8254, lapic), macppc,
mips64/octeon, and sparc64. Tested on arm/armv7 (agtimer(4)) by
phessler@ and jmatthew@. Tested on m88k/luna88k by aoyama@. Tested
on powerpc64 by gkoehler@ and mlarkin@. Tested on riscv64 by
jmatthew@.

Thread: https://marc.info/?l=openbsd-tech&m=169195251322149&w=2

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statclock: move profil(2), GPROF code to profclock(), gmonclock()

This patch isolates profil(2) and GPROF from statclock(). Currently,
statclock() implements both profil(2) and GPROF through a comp

statclock: move profil(2), GPROF code to profclock(), gmonclock()

This patch isolates profil(2) and GPROF from statclock(). Currently,
statclock() implements both profil(2) and GPROF through a complex
mechanism involving both platform code (setstatclockrate) and the
scheduler (pscnt, psdiv, and psratio). We have a machine-independent
interface to the clock interrupt hardware now, so we no longer need to
do it this way.

- Move profil(2)-specific code from statclock() to a new clock
interrupt callback, profclock(), in subr_prof.c. Each
schedstate_percpu has its own profclock handle. The profclock is
enabled/disabled for a given CPU when it is needed by the running
thread during mi_switch() and sched_exit().

- Move GPROF-specific code from statclock() to a new clock interrupt
callback, gmonclock(), in subr_prof.c. Where available, each cpu_info
has its own gmonclock handle . The gmonclock is enabled/disabled for
a given CPU via sysctl(2) in prof_state_toggle().

- Both profclock() and gmonclock() have a fixed period, profclock_period,
that is initialized during initclocks().

- Export clockintr_advance(), clockintr_cancel(), clockintr_establish(),
and clockintr_stagger() via <sys/clockintr.h>. They have external
callers now.

- Delete pscnt, psdiv, psratio. From schedstate_percpu, also delete
spc_pscnt and spc_psdiv. The statclock frequency is not dynamic
anymore so these variables are now useless.

- Delete code/state related to the dynamic statclock frequency from
kern_clockintr.c. The statclock frequency can still be pseudo-random,
so move the contents of clockintr_statvar_init() into clockintr_init().

With input from miod@, deraadt@, and claudio@. Early revisions
cleaned up by claudio. Early revisions tested by claudio@. Tested by
cheloha@ on amd64, arm64, macppc, octeon, and sparc64 (sun4v).
Compile- and boot- tested on i386 by mlarkin@. riscv64 compilation
bugs found by mlarkin@. Tested on riscv64 by jca@. Tested on
powerpc64 by gkoehler@.

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timecounting: remove incomplete PPS support

The timecounting code has had stubs for pulse-per-second (PPS) polling
since it was imported in 2004. At this point it seems unlikely that
anyone is goin

timecounting: remove incomplete PPS support

The timecounting code has had stubs for pulse-per-second (PPS) polling
since it was imported in 2004. At this point it seems unlikely that
anyone is going to finish adding PPS support, so let's remove the stubs:

- Delete the dead tc_poll_pps() call from tc_windup().
- Remove all tc_poll_pps symbols from the kernel.

Link: https://marc.info/?l=openbsd-tech&m=167519035723210&w=2

ok miod@

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mips64, loongson, octeon: switch to clockintr

- Remove mips64-specific clock interrupt scheduling bits from cpu_info.
- Add missing tick_nsec initialization to cpu_initclocks().
- Disable the glxclk

mips64, loongson, octeon: switch to clockintr

- Remove mips64-specific clock interrupt scheduling bits from cpu_info.
- Add missing tick_nsec initialization to cpu_initclocks().
- Disable the glxclk interrupt clock on loongson. visa@/miod@ say it
can be removed later if it isn't useful for anything else.
- Wire up cp0_intrclock.

Notes:

- The loongson apm_suspend() changes are untested, but deraadt@ claims
APM suspend/resume on loongson doesn't work anyway.
- loongson and octeon now have a randomized statclock(), stathz = hz.

With input from miod@, visa@. Tested by miod@, visa@.

Link: https://marc.info/?l=openbsd-tech&m=166776379603497&w=2

ok visa@ mlarkin@

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Simplfity setregs() by passing it the ps_strings and switching
sys_execve() to return EJUSTRETURN.

setregs() is the MD routine used by sys_execve() to set up the
thread's trapframe and PCB such that

Simplfity setregs() by passing it the ps_strings and switching
sys_execve() to return EJUSTRETURN.

setregs() is the MD routine used by sys_execve() to set up the
thread's trapframe and PCB such that, on 'return' to userspace, it
has the register values defined by the ABI and otherwise zero. It
had to set the syscall retval[] values previously because the normal
syscall return path overwrites a couple registers with the retval[]
values. By instead returning EJUSTRETURN that and some complexity
with program-counter handling on m88k and sparc64 goes away.

Also, give setregs() add a 'struct ps_strings *arginfo' argument
so powerpc, powerpc64, and sh can directly get argc/argv/envp
values for registers instead of copyin()ing the one in userspace.

Improvements from miod@ and millert@
Testing assistance miod@, kettenis@, and aoyama@
ok miod@ kettenis@

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mips64, octeon, loonson: trigger deferred clock interrupts from splx(9)

As with powerpc, powerpc64, and riscv64, on mips64 platforms we need
to isolate the clock interrupt schedule from the MD clock

mips64, octeon, loonson: trigger deferred clock interrupts from splx(9)

As with powerpc, powerpc64, and riscv64, on mips64 platforms we need
to isolate the clock interrupt schedule from the MD clock interrupt
code. To do this, we need to stop deferring clock interrupt work
until the next tick and instead defer the work until we logically
unmask the clock interrupt from splx(9).

Add a boolean (ci_clock_deferred) to the cpu_info struct to note
whether we need to trigger the clock interrupt by hand, and then
do so from splx(9) by calling md_triggerclock().

Currently md_triggerclock is only ever set to cp0_trigger_int5(). The
routine takes great care to ensure that INT5 has fired or will fire
before returning.

There are some loongson machines that use glxclk instead of CP0. They
can be switched to use CP0 later.

With input and advice from visa@ and miod@.

Compiled and extensively tested by visa@ and miod@ on various octeon
and loongson machines. No issues seen on octeon machines. miod@ saw
some odd things on loongsoon, but suggests that all issues are
probably unrelated to this patch.

Link: https://marc.info/?l=openbsd-tech&m=165929192702632&w=2

ok visa@, miod@

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Retire OpenBSD/sgi.

OK deraadt@

Remove unused RM7000 ICR handling.

timecounting: use C99-style initialization for all timecounter structs

The timecounter struct is large and I think it may change in the
future. Changing it later will be easier if we use C99-style

timecounting: use C99-style initialization for all timecounter structs

The timecounter struct is large and I think it may change in the
future. Changing it later will be easier if we use C99-style
initialization for all timecounter structs. It also makes reading the
code a bit easier.

For reasons I cannot explain, switching to C99-style initialization
sometimes changes the hash of the resulting object file, even though
the resulting struct should be the same. So there is a binary change
here, but only sometimes. No behavior should change in either case.

I can't compile-test this everywhere but I have been staring at the
diff for days now and I'm relatively confident this will not break
compilation. Fingers crossed.

ok gnezdo@

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kernel, sysctl(8): remove dead variable: tickadj

The global "tickadj" variable is a remnant of the old NTP adjustment
code we used in the kernel before the current timecounter subsystem
was imported

kernel, sysctl(8): remove dead variable: tickadj

The global "tickadj" variable is a remnant of the old NTP adjustment
code we used in the kernel before the current timecounter subsystem
was imported from FreeBSD circa 2004 or 2005.

Fifteen years hence it is completely vestigial and we can remove it.
We probably should have removed it long ago but I guess it slipped
through the cracks. FreeBSD removed it in 2002:

https://cgit.freebsd.org/src/commit/?id=e1d970f1811e5e1e9c912c032acdcec6521b2a6d

NetBSD and DragonflyBSD can probably remove it, too.

We export tickadj via the kern.clockrate sysctl(2), so update sysctl.2
and sysctl(8) accordingly. Hypothetically this change could break
someone's sysctl(8) parsing script. I don't think that's very likely.

ok mvs@

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Synchronize each core's CP0 cycle counter using the IO clock counter.
This makes the cycle counter usable as timecounter on multiprocessor
machines.

Idea from Linux.

Tested on CN5020, CN6120, CN713

Synchronize each core's CP0 cycle counter using the IO clock counter.
This makes the cycle counter usable as timecounter on multiprocessor
machines.

Idea from Linux.

Tested on CN5020, CN6120, CN7130 and CN7360.

Looks reasonable to kettenis@

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Add support for timeconting in userland.

This diff exposes parts of clock_gettime(2) and gettimeofday(2) to
userland via libc eliberating processes from the need for a context
switch everytime they

Add support for timeconting in userland.

This diff exposes parts of clock_gettime(2) and gettimeofday(2) to
userland via libc eliberating processes from the need for a context
switch everytime they want to count the passage of time.

If a timecounter clock can be exposed to userland than it needs to set
its tc_user member to a non-zero value. Tested with one or multiple
counters per architecture.

The timing data is shared through a pointer found in the new ELF
auxiliary vector AUX_openbsd_timekeep containing timehands information
that is frequently updated by the kernel.

Timing differences between the last kernel update and the current time
are adjusted in userland by the tc_get_timecount() function inside the
MD usertc.c file.

This permits a much more responsive environment, quite visible in
browsers, office programs and gaming (apparently one is are able to fly
in Minecraft now).

Tested by robert@, sthen@, naddy@, kmos@, phessler@, and many others!

OK from at least kettenis@, cheloha@, naddy@, sthen@

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Retire unused <mips64/dev/clockvar.h> interface.

Make inittodr() and resettodr() MI.

ok deraadt@, mpi@, visa@
ok cheloha@ as well (would have preferred in new file for this code)

Use todr_gettime() in cp0_calibrate() on mips64.

This allows changing RTC drivers from <mips64/dev/clockvar.h>
to <dev/clock_subr.h> API.

OK kettenis@

Initialize the timeval passed to todr_gettime() with the base time from
the file system such that implementations can use it to guess the right
century.

ok mpi@

Use the same inittodr()/resettodr() implementation as on
amd64/arm64/armv7/hppa/i386/macppc/sparc64 and move it to the end of
mips64_machdep.c. Wrap the existing tod_get and tod_set hooks into
somet

Use the same inittodr()/resettodr() implementation as on
amd64/arm64/armv7/hppa/i386/macppc/sparc64 and move it to the end of
mips64_machdep.c. Wrap the existing tod_get and tod_set hooks into
something that can be used as a todr_handle.

ok visa@

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Make octeon kernels compile with DEBUG.

Based on a diff from jj@. Thank you!

Let the kernel utilize the FPU if one is available, even when the
FPUEMUL option is enabled. This benefits OCTEON III systems which can
run floating-point operations natively.

Feedback from and OK m

Let the kernel utilize the FPU if one is available, even when the
FPUEMUL option is enabled. This benefits OCTEON III systems which can
run floating-point operations natively.

Feedback from and OK miod@; he also helped with testing.

Tested on octeon without FPU (CN5020, CN6120) and with FPU (CN7130),
as well as on sgi/IP27 (MP R16000), sgi/IP32 (R5000), and
loongson (3A1000).

show more ...

Ansify function definitions.

Move loongson/octeon/sgi unmap_startup() under arch/mips64.

Invalidate OCTEON icache after TLB ASID wraparound, otherwise userspace
might execute stale instructions. The cache is virtually tagged and does
not seem to pick up TLB alterations automatically.

Remove RM7000/RM9000-specific performance counter code. It originates
from PMON2000 and has not been enabled on OpenBSD.

Suggested by and ok miod@ (after seeing a quad_t cleanup patch of mine)

Rename mips64's trap_frame into trapframe.

For coherency with other archs and in order to use it in MI code.

ok visa@, tobiasu@

Use MAP_INHERIT_* for the 'inh' argument to the UMV_MAPFLAG() macro,
eliminating the must-be-kept-in-sync UVM_INH_* macros

ok deraadt@ tedu@