Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Remove dead code and dead comments, most notably the implemenation of the
now-obsolete setfault(). No NetBSD code exists in the AIM locore files, so
update the copyrights there.

Make 32-bit PowerPC kernels, like 64-bit PowerPC kernels, position-independent
executables. The goal here, not yet accomplished, is to let the e500 kernel
run under QEMU by setting KERNBASE to something that fits in low memory and
then having the kernel relocate itself at runtime.

Remove FreeBSD/wii.

This port failed to gain traction and probably only a couple Wii consoles
ran FreeBSD all the way to single user mode with an md(4). IPC
support was never implemented, so it was impossible to use any peripheral

Any further development, if any, will happen at https://github.com/rpaulo/wii.

Discussed with: nathanw (a long time ago), jhibbits

Refactor PowerPC (especially AIM) init sequence to be less baroque.

MFC after: 2 months

- For kernel compiled only with KDTRACE_HOOKS and not any lock debugging
option, unbreak the lock tracing release semantic by embedding
calls to LOCKSTAT_PROFILE_RELEASE_LOCK() direclty in the inlined
version of the releasing functions for mutex, rwlock and sxlock.
Failing to do so skips the lockstat_probe_func invokation for
unlocking.
- As part of the LOCKSTAT support is inlined in mutex operation, for
kernel compiled without lock debugging options, potentially every
consumer must be compiled including opt_kdtrace.h.
Fix this by moving KDTRACE_HOOKS into opt_global.h and remove the
dependency by opt_kdtrace.h for all files, as now only KDTRACE_FRAMES
is linked there and it is only used as a compile-time stub [0].

[0] immediately shows some new bug as DTRACE-derived support for debug
in sfxge is broken and it was never really tested. As it was not
including correctly opt_kdtrace.h before it was never enabled so it
was kept broken for a while. Fix this by using a protection stub,
leaving sfxge driver authors the responsibility for fixing it
appropriately [1].

Sponsored by: EMC / Isilon storage division
Discussed with: rstone
[0] Reported by: rstone
[1] Discussed with: philip

Setup BAT0 and BAT1 on the Wii.

This is the missing piece for FreeBSD/Wii, but there's still a lot of
work ahead. We have to reset the MMU in locore before continuing
the boot process because we don't know how the boot loaders might
have setup the BATs. We also disable the PCI BAT because there's no PCI
bus on the Wii.

Thanks to Nathan Whitehorn and Peter Grenhan for their help.

Submitted by: Margarida Gouveia

Implement DTrace for PowerPC. This includes both 32-bit and 64-bit.

There is one known issue: Some probes will display an error message along the
lines of: "Invalid address (0)"

I tested this with both a simple dtrace probe and dtruss on a few different
binaries on 32-bit. I only compiled 64-bit, did not run it, but I don't expect
problems without the modules loaded. Volunteers are welcome.

MFC after: 1 month

The `end' symbol doesn't match the end of the kernel image because it's
relative to the start address (unless the start address is 0, which is
not the case).
This is currently not a problem because all powerpc architectures are
using loader(8) which passes metadata to the kernel including the
correct `endkernel' address. If we don't use loader(8), register 4
and 5 will have the size of the kernel ELF file, not its end address.
We fix that simply by adding `kernel_text' to `end' to compute
`endkernel'.

Discussed with: nathanw

Zero BSS on start, in case the ELF loader that started the kernel did not
do this for us. This can happen on some embedded systems.

Submitted by: rpaulo

This a follow up commit from r224216 for powerpc 32-bit. Increase
the storage size for sintrcnt/sintrnames to .long.

Reviewed by: nwhitehorn
Approved by: re (kib)

- Remove the eintrcnt/eintrnames usage and introduce the concept of
sintrcnt/sintrnames which are symbols containing the size of the 2
tables.
- For amd64/i386 remove the storage of intr* stuff from assembly files.
This area can be widely improved by applying the same to other
architectures and likely finding an unified approach among them and
move the whole code to be MI. More work in this area is expected to
happen fairly soon.

No MFC is previewed for this patch.

Tested by: pluknet
Reviewed by: jhb
Approved by: re (kib)

Use the ABI-mandated thread pointer register (r2 for ppc32, r13 for ppc64)
instead of a PCPU field for curthread. This averts a race on SMP systems
with a high interrupt rate where the thread looking up the value of
curthread could be preempted and migrated between obtaining the PCPU
pointer and reading the value of pc_curthread, resulting in curthread being
observed to be the current thread on the thread's original CPU. This played
merry havoc with the system, in particular with mutexes. Many thanks to
jhb for helping me work this one out.

Note that Book-E is in principle susceptible to the same problem, but has
not been modified yet due to lack of Book-E hardware.

MFC after: 2 weeks

MFpseries:
Renovate and improve the AIM Open Firmware support:
- Add RTAS (Run-Time Abstraction Services) support, found on all IBM systems
and some Apple ones
- Improve support for 32-bit real mode Open Firmware systems
- Pull some more OF bits over from the AIM directory
- Fix memory detection on IBM LPARs and systems with more than one /memory
node (by andreast@)

MFppc64:

Kernel sources for 64-bit PowerPC, along with build-system changes to keep
32-bit kernels compiling (build system changes for 64-bit kernels are
coming later). Existing 32-bit PowerPC kernel configurations must be
updated after this change to specify their architecture.

Modularize the Open Firmware client interface to allow run-time switching
of OFW access semantics, in order to allow future support for real-mode
OF access and flattened device frees. OF client interface modules are
implemented using KOBJ, in a similar way to the PPC PMAP modules.

Because we need Open Firmware to be available before mutexes can be used on
sparc64, changes are also included to allow KOBJ to be used very early in
the boot process by only using the mutex once we know it has been initialized.

Reviewed by: marius, grehan

Add support for kernel profiling for both AIM and BookE.

Obtained from: Juniper Networks, Inc (BookE support).

MFp4: SMP support

Make sure tmpstk is aligned and make it 8KB in size -- not 8KB+16.

Allocate a stack (with optional guard pages) for thread0 and
switch to it before calling mi_startup().

For AIM, have cpu_idle() set MSR_POW when the powerpc_pow_enabled
variable is set. On my Mac Mini this puts the CPU in NAP mode when
the kernel is idle and, any technical or environmental reasons
aside, avoids that I have to listen to the fan all day :-)

Avoid hardcoding the kernel link address in the linker script.
Use KERNBASE instead. While here, move the text sections
forward to the beginning of the text segment.

Forced commit to record that this file was repocopied from
src/sys/powerpc/powerpc and modified for its new location.

Copy SPRG0-3 registers at boot-time and restore when calling into
OpenFirmware. FreeBSD/ppc uses SPRG0 as the per-cpu data area pointer,
and SPRG1-3 as temporary registers during exception handling. There
have been a few instances where OpenFirmware does require these to
be part of it's context, such as cd-booting an eMac.

reported by: many
MFC after: 3 days

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

Instead of "OpenFirmware", "openfirmware", etc. use the official spelling
"Open Firmware" from IEEE 1275 and OpenFirmware.org (no pun intended).

Ok'ed by: tmm

Bring KDB stack size into line with thread stack size (4 pages).

No need for ddb option. Never a need for ipkdb option.

Interrupt statistics, vmstat -i now works.

Submitted by: Suleiman Souhlal <refugee@segfaulted.com>
Slightly modified by: grehan
Derived from: i386

- Add definition for GET_CPUINFO, required by new trap_subr code
- garbage-collect unused defs

Remove BAT invalidation. This is done later in the boot sequence,
so isn't required here, and seems to cause problems when booting
from disk.

Approved by: benno

- moved intrcnt/intrnames to locore.s to fix sysctl -a panic

Approved by: benno

- Make sure we don't trample our metadata pointer in our initial bootstrap.
- Load metadata parameters.

- Use tmpstk exclusively in the init path.
- Remove redundant code.

Submitted by: Peter Grehan <peterg@ptree32.com.au>

Many fixes to low-level trap and interrupt handling:

- Tidy up clock code. Don't repeatedly call hardclock().
- Remove intrnames, decrnest and intrcnt from locore.s
- Coalesce all trap handling into a single stub that then calls a dispatch
function.

Submitted by: Peter Grehan <peterg@ptree32.com.au>

Commit of stuff that's been sitting in my tree for a while.

Highlights include:
- New low-level trap code from NetBSD. The high level code still needs a lot
of work.
- Fixes for some pmap handling in thread switching.
- The kernel will now get to attempting to jump into init in user mode. There
are some pmap/trap issues which prevent it from actually getting there though.

Obtained from: NetBSD (parts)

- Prevent the decrementer interrupt handler from nesting.
- Catch some more cases of PSL_EE and PSL_RI getting out of sync.

Make fork work, at least for kthreads. Switching still has some issues.

Complete rework of the PowerPC pmap and a number of other bits in the early
boot sequence.

The new pmap.c is based on NetBSD's newer pmap.c (for the mpc6xx processors)
which is 70% faster than the older code that the original pmap.c was based
on. It has also been based on the framework established by jake's initial
sparc64 pmap.c.

There is no change to how far the kernel gets (it makes it to the mountroot
prompt in psim) but the new pmap code is a lot cleaner.

Obtained from: NetBSD (pmap code)

Overhaul the per-CPU support a bit:

- The MI portions of struct globaldata have been consolidated into a MI
struct pcpu. The MD per-CPU data are specified via a macro defined in
machine/pcpu.h. A macro was chosen over a struct mdpcpu so that the
interface would be cleaner (PCPU_GET(my_md_field) vs.
PCPU_GET(md.md_my_md_field)).
- All references to globaldata are changed to pcpu instead. In a UP kernel,
this data was stored as global variables which is where the original name
came from. In an SMP world this data is per-CPU and ideally private to each
CPU outside of the context of debuggers. This also included combining
machine/globaldata.h and machine/globals.h into machine/pcpu.h.
- The pointer to the thread using the FPU on i386 was renamed from
npxthread to fpcurthread to be identical with other architectures.
- Make the show pcpu ddb command MI with a MD callout to display MD
fields.
- The globaldata_register() function was renamed to pcpu_init() and now
init's MI fields of a struct pcpu in addition to registering it with
the internal array and list.
- A pcpu_destroy() function was added to remove a struct pcpu from the
internal array and list.

Tested on: alpha, i386
Reviewed by: peter, jake

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

Submitted by: jhb

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

Forced commit due to commit mishap.

Change the name of the entry point symbol from 'start' to '__start' to be in
sync with the ldscript.

Fix comment breakage.

Bring in NetBSD code used in the PowerPC port.

Reviewed by: obrien, dfr
Obtained from: NetBSD