Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC: r230628

Mark cpu_{halt,reset}() as __dead2 as appropriate.

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

- For Cheetah- and Zeus-class CPUs don't flush all unlocked entries from
the TLBs in order to get rid of the user mappings but instead traverse
them an flush only the latter like we also do for the Spitfire-class.
Also flushing the unlocked kernel entries can cause instant faults which
when called from within cpu_switch() are handled with the scheduler lock
held which in turn can cause timeouts on the acquisition of the lock by
other CPUs. This was easily seen with a 16-core V890 but occasionally
also happened with 2-way machines.
While at it, move the SPARC64-V support code entirely to zeus.c. This
causes a little bit of duplication but is less confusing than partially
using Cheetah-class bits for these.
- For SPARC64-V ensure that 4-Mbyte page entries are stored in the 1024-
entry, 2-way set associative TLB.
- In {d,i}tlb_get_data_sun4u() turn off the interrupts in order to ensure
that ASI_{D,I}TLB_DATA_ACCESS_REG actually are read twice back-to-back.

Tested by: Peter Jeremy (16-core US-IV), Michael Moll (2-way SPARC64-V)

Some machines can not only consist of CPUs running at different speeds
but also of different types, f.e. Sun Fire V890 can be equipped with a
mix of UltraSPARC IV and IV+ CPUs, requiring different MMU initialization
and different workarounds for model specific errata. Therefore move the
CPU implementation number from a global variable to the per-CPU data.
Functions which are called before the latter is available are passed the
implementation number as a parameter now.

Flesh out MMU and cache handling of cheetah-class CPUs.

Clean out sysctl machdep.* related defines.

The cmos clock related stuff should really be in MI code.

Tweak how the MD code calls the fooclock() methods some. Instead of
passing a pointer to an opaque clockframe structure and requiring the
MD code to supply CLKF_FOO() macros to extract needed values out of the
opaque structure, just pass the needed values directly. In practice this
means passing the pair (usermode, pc) to hardclock() and profclock() and
passing the boolean (usermode) to hardclock_cpu() and hardclock_process().
Other details:
- Axe clockframe and CLKF_FOO() macros on all architectures. Basically,
all the archs were taking a trapframe and converting it into a clockframe
one way or another. Now they can just extract the PC and usermode values
directly out of the trapframe and pass it to fooclock().
- Renamed hardclock_process() to hardclock_cpu() as the latter is more
accurate.
- On Alpha, we now run profclock() at hz (profhz == hz) rather than at
the slower stathz.
- On Alpha, for the TurboLaser machines that don't have an 8254
timecounter, call hardclock() directly. This removes an extra
conditional check from every clock interrupt on Alpha on the BSP.
There is probably room for even further pruning here by changing Alpha
to use the simplified timecounter we use on x86 with the lapic timer
since we don't get interrupts from the 8254 on Alpha anyway.
- On x86, clkintr() shouldn't ever be called now unless using_lapic_timer
is false, so add a KASSERT() to that affect and remove a condition
to slightly optimize the non-lapic case.
- Change prototypeof arm_handler_execute() so that it's first arg is a
trapframe pointer rather than a void pointer for clarity.
- Use KCOUNT macro in profclock() to lookup the kernel profiling bucket.

Tested on: alpha, amd64, arm, i386, ia64, sparc64
Reviewed by: bde (mostly)

Instead of calling ia32_pause() conditionally on __i386__ or __amd64__
being defined, define and use a new MD macro, cpu_spinwait(). It only
expands to something on i386 and amd64, so the compiled code should be
identical.

Name of the macro found by: jhb
Reviewed by: jhb

Backed out previous commit. Blind substitution of dev_t by `struct cdev *'
was just wrong here because the dev_t's are user dev_t's.

Do the dreaded s/dev_t/struct cdev */
Bump __FreeBSD_version accordingly.

Remove advertising clause from University of California Regent's
license, per letter dated July 22, 1999 and email from Peter Wemm,
Alan Cox and Robert Watson.

Approved by: core, peter, alc, rwatson

Further cleanup <machine/cpu.h> and <machine/md_var.h>: move the MI
prototypes of cpu_halt(), cpu_reset() and swi_vm() from md_var.h to
cpu.h. This affects db_command.c and kern_shutdown.c.

ia64: move all MD prototypes from cpu.h to md_var.h. This affects
madt.c, interrupt.c and mp_machdep.c. Remove is_physical_memory().
It's not used (vm_machdep.c).

alpha: the MD prototypes have been left in cpu.h with a comment
that they should be there. Moving them is left for later. It was
expected that the impact would be significant enough to be done in
a seperate commit.

powerpc: MD prototypes left in cpu.h. Comment added.

Suggested by: bde
Tested with: make universe (pc98 incomplete)

Add declarations for btext and etext.

Define CKLF_PC in terms of TRAPF_PC.

Implement CLKF_USERMODE so that user time is accounted properly.

Submitted by: tmm

Fix get_cyclecount. Wrap in ifdef _KERNEL.

KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.

Sorry john! (your next MFC will be a doosie!)

Reviewed by: peter@freebsd.org, dillon@freebsd.org

X-MFC after: ha ha ha ha

Use the correct copyrights. Note where most of this came from.

Requested by: obrien

- Close races with signals and other AST's being triggered while we are in
the process of exiting the kernel. The ast() function now loops as long
as the PS_ASTPENDING or PS_NEEDRESCHED flags are set. It returns with
preemption disabled so that any further AST's that arrive via an
interrupt will be delayed until the low-level MD code returns to user
mode.
- Use u_int's to store the tick counts for profiling purposes so that we
do not need sched_lock just to read p_sticks. This also closes a
problem where the call to addupc_task() could screw up the arithmetic
due to non-atomic reads of p_sticks.
- Axe need_proftick(), aston(), astoff(), astpending(), need_resched(),
clear_resched(), and resched_wanted() in favor of direct bit operations
on p_sflag.
- Fix up locking with sched_lock some. In addupc_intr(), use sched_lock
to ensure pr_addr and pr_ticks are updated atomically with setting
PS_OWEUPC. In ast() we clear pr_ticks atomically with clearing
PS_OWEUPC. We also do not grab the lock just to test a flag.
- Simplify the handling of Giant in ast() slightly.

Reviewed by: bde (mostly)

The author isn't a [UC] Regents. Correct the copyright language.

Flesh out the sparc64 port considerably. This contains:
- mostly complete kernel pmap support, and tested but currently turned
off userland pmap support
- low level assembly language trap, context switching and support code
- fully implemented atomic.h and supporting cpufunc.h
- some support for kernel debugging with ddb
- various header tweaks and filling out of machine dependent structures

Add skeleton machine dependent headers and c files for a port of freebsd
to a new architecture. This is the base of the sparc64 port, but contains
limited machine dependent code, and can be used a base for ports. Included
are:
- standard machine dependent headers, tweaked for a 64 bit, big endian
architecture, including empty versions of all the machine dependent
structures
- a machine independent atomic.h, which can be used until a port has
support for interrupts and the operations really need to be atomic
- stub versions of all the machine dependent functions, which panic
when called and print out the name of the function that needs to
be implemented. functions which are normally in assembly files are
not included, but this should reduce the number of different undefined
references on the first few compiles from hundreds to 5 or 6
Given minimal startup code and console support it should be trivial to
make this compile and run the first few sysinits on almost any architecture.

Requested by: alfred, imp, jhb