- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

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

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Revert r253748,253749

This WIP should not have been committed yet.

Pointyhat to: avg

put contents of cpu.h under _KERNEL

no userland-serviceable parts inside

MFC after: 20 days

Move the prototype for savectx from cpu.h to pcb.h, as it is on other
platforms, as well as putting it in an #ifdef KERNEL block.

MFC after: 2 weeks

Add a convenience macro for the returns_twice attribute, and apply it to
the prototypes of the appropriate functions (getcontext, savectx,
setjmp, sigsetjmp and vfork).

MFC after: 2 weeks

We don't need kcopy() in any of the remaining places it is used, so
remove it.

MFC after: 2 weeks

Add a CPU features framework on PowerPC and simplify CPU setup a little
more. This provides three new sysctls to user space:
hw.cpu_features - A bitmask of available CPU features
hw.floatingpoint - Whether or not there is hardware FP support
hw.altivec - Whether or not Altivec is available

PR: powerpc/139154
MFC after: 10 days

Declare btext and etext. Needed by sys/kern/subr_prof.c for
for kernel profiling.

Add kdb_cpu_sync_icache(), intended to synchronize instruction
caches with data caches after writing to memory. This typically
is required to make breakpoints work on ia64 and powerpc. For
those architectures the function is implemented.

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)

/* -> /*- for license, minor formatting changes

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

DELAY must be a routine, not a macro definition.

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)

Remove unused bootpath[] variable. It conflicted with a declaration
in the sunlabel utility, causing build problems.

Prepended underscores to macro local vars, avoiding gcc "declaration
shadows global" warning

Approved by: benno

Additional machdep sysctl constants needed for userland utils

Approved by: benno

Move the kcopy() function from trap.c to machdep.c. Add a prototype.

GC an extraneous prototype of delay().

Remove __P.

Reveiwed by: benno

Add a missing (.

Clean up the trap handling code and make it consistent with the other platforms.

Submitted by: jhb

- Correct the type of the argument to delay() so as to not conflict with
sys/boot/common/bootstrap.h.
- Add a prototype for fork_trampoline().

Update PowerPC MD code to compile and do initial bootstrap based on
recent changes (KSE and VM requiring physmem to be setup).

Reviewed by: benno, jhb, julian

- 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)

Add TRAPF_* macros required by MI-ification of ast() and userret().

Submitted by: Mark Peek <mark@whistle.com>

Add a new MI pointer to the process' trapframe p_frame instead of using
various differently named pointers buried under p_md.

Reviewed by: jake (in principle)

Bring in NetBSD code used in the PowerPC port.

Reviewed by: obrien, dfr
Obtained from: NetBSD