- Copy stable/10@296371 to releng/10.3 in preparation for 10.3-RC1
builds.
- Update newvers.sh to reflect RC1.
- Update __FreeBSD_version to reflect 10.3.
- Update default pkg(8) configuration to use the quarterly branch.

Approved by: re (implicit)

MFC r258268, r258271, r258272, r258274, r258275, r258427, r258694, r258696,
r258697, r258757

Do not assume a value for #address-cells when parsing the OF translations
map. This allows the kernel to get farther with OpenBIOS on 64-bit CPUs.

Actually look up #address-cells instead of assuming it is correlated with
the Uninorth version number.

#interrupt-cells belongs to the iparent, not the device parent.

Add a sysctl to allow disabling resetting the OF syscons.

For PCI<->PCI bridges, #address-cells may be 3.

Make RTAS calls, which call setfault() to recover from machine checks,
preserve any existing fault buffer.

badaddr() is used only in the grackle PCI driver, so move its definition
there. Clean up a spurious setfault() declaration as well.

This [phyp_console] driver doesn't need the /options node, so don't check
for it.

Use the Open Firmware-based CPU frequency determination as a generic
fallback if we can't measure CPU frequency. This is also useful on a
variety of embedded systems using FDT.

MFC r257161, r257169, r257178, r257190, r257191

Add pmap_mapdev_attr() and pmap_kenter_attr() interfaces.

Fix concurrency issues with TLB1 updates and make pmap_kextract() search
TLB1 mappings as well

Interrelated improvements to early boot mappings:
- Remove explicit requirement that the SOC registers be found except as an
optimization (although the MPC85XX LAW drivers still require they be found
externally, which should change).
- Remove magic CCSRBAR_VA value.
- Allow bus_machdep.c's early-boot code to handle non 1:1 mappings and
systems not in real-mode or global 1:1 maps in early boot.
- Allow pmap_mapdev() on Book-E to reissue previous addresses if the
area is already mapped. Additionally have it check all mappings, not
just the CCSR area.

Add some extra sanity checking and checks to printf format specifiers.

Bump initial TLB size. The kernel is not necessarily less than 16 MB

Handle (in a slightly ugly way) ePAPR-type loaders that just place a
device tree into r3.

MFC r256792, r256793, r256799 (by nwhitehorn): Unify AIM and booke code.

MFC r261309

Unbreak non-SMP builds. This was broken by r259284. Also, reorganize the
code introduced in that revision a bit.

MFC r257991, r257992, 257993, 258504

r257991:
Consolidate Apple firmware hacks and improve them by switching on the
presence of mac-io devices in the tree, which uniquely identifies Apple
hardware.

r257992:
Allow OF_decode_addr() to also be able to map resources on big-endian
devices. To this end, make PCI device detection rely on the device_type
field rather than name, as per the standard.

r257993:

Make tsec work with the device tree present on the RB800. The previous code
assumed that the MDIO bus was a direct child of the Ethernet interface. It
may not be and indeed on many device trees is not. While here, add proper
locking for MII transactions, which may be on a bus shared by several MACs.

r258504:

Save and restore the trap vectors when doing OF calls on pSeries machines.

It turned out that on pSeries machines the call into OF modified the trap
vectors and this made further behaviour unpredictable.

With this commit I'm now able to boot multi user on a network booted
environment on my IntelliStation 285. This is a POWER5+ machine.

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

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

Switch the vm_object mutex to be a rwlock. This will enable in the
future further optimizations where the vm_object lock will be held
in read mode most of the time the page cache resident pool of pages
are accessed for reading purposes.

The change is mostly mechanical but few notes are reported:
* The KPI changes as follow:
- VM_OBJECT_LOCK() -> VM_OBJECT_WLOCK()
- VM_OBJECT_TRYLOCK() -> VM_OBJECT_TRYWLOCK()
- VM_OBJECT_UNLOCK() -> VM_OBJECT_WUNLOCK()
- VM_OBJECT_LOCK_ASSERT(MA_OWNED) -> VM_OBJECT_ASSERT_WLOCKED()
(in order to avoid visibility of implementation details)
- The read-mode operations are added:
VM_OBJECT_RLOCK(), VM_OBJECT_TRYRLOCK(), VM_OBJECT_RUNLOCK(),
VM_OBJECT_ASSERT_RLOCKED(), VM_OBJECT_ASSERT_LOCKED()
* The vm/vm_pager.h namespace pollution avoidance (forcing requiring
sys/mutex.h in consumers directly to cater its inlining functions
using VM_OBJECT_LOCK()) imposes that all the vm/vm_pager.h
consumers now must include also sys/rwlock.h.
* zfs requires a quite convoluted fix to include FreeBSD rwlocks into
the compat layer because the name clash between FreeBSD and solaris
versions must be avoided.
At this purpose zfs redefines the vm_object locking functions
directly, isolating the FreeBSD components in specific compat stubs.

The KPI results heavilly broken by this commit. Thirdy part ports must
be updated accordingly (I can think off-hand of VirtualBox, for example).

Sponsored by: EMC / Isilon storage division
Reviewed by: jeff
Reviewed by: pjd (ZFS specific review)
Discussed with: alc
Tested by: pho

Unbreak tinderbox.

Set mdp only under #ifdef WII.

On Nintendo Wii CPUs, the mdp value will be garbage. Set it to NULL
so as to not confuse things.

Submitted by: Margarida Gouveia

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

MFC after: 2 weeks

Reduce the frequency that the PowerPC/AIM pmaps invalidate instruction
caches, by invalidating kernel icaches only when needed and not flushing
user caches for shared pages.

Suggested by: kib
MFC after: 2 weeks

Rework SLB trap handling so that double-faults into an SLB trap handler are
possible, and double faults within an SLB trap handler are not. The result
is that it possible to take an SLB fault at any time, on any address, for
any reason, at any point in the kernel.

This lets us do two important things. First, it removes the (soft) 16 GB RAM
ceiling on PPC64 as well as any architectural limitations on KVA space.
Second, it lets the kernel tolerate poorly designed hypervisors that
have a tendency to fail to restore the SLB properly after a hypervisor
context switch.

MFC after: 6 weeks

Implement hwpmc counting PMC support for PowerPC G4+ (MPC745x/MPC744x).
Sampling is in progress.

Approved by: nwhitehorn (mentor)
MFC after: 9.0-RELEASE

Use a global __pure2 function instead of a global register variable for
curthread, like on x86 and sparc64. This makes the kernel somewhat more
clang friendly, which doesn't support global register variables.

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

The POWER7 has only 32 SLB slots instead of 64, like other supported
64-bit PowerPC CPUs. Add infrastructure to support variable numbers of
SLB slots and move the user slot from 63 to 0, so that it is always
available.

Explicitly initialize the first thread's MSR to PSL_KERNSET.

Include the modules area in the mapped kernel code. This fixes the kernel's
access to modules and loader metadata when started from real mode, but
without a direct map.

Add leading zeros when printing the physical memory chunks on __powerpc64__.

Approved by: nwhitehorn (mentor)

Mostly revert r219468, as I had misremembered the C standard regarding
the size of an extern array.

Keep one change from strncpy to strlcpy.

Use MAXPATHLEN rather than the size of an extern array when copying the
kernel name. Also consistenly use strlcpy().

Suggested by: Warner Losh

Make MSGBUF_SIZE kernel option a loader tunable kern.msgbufsize.

Submitted by: perryh pluto.rain.com (previous version)
Reviewed by: jhb
Approved by: kib (mentor)
Tested by: universe

Remove use of a separate ofw_pmap on 32-bit CPUs. Many Open Firmware
mappings need to end up in the kernel anyway since the kernel begins
executing in OF context. Separating them adds needless complexity,
especially since the powerpc64 and mmu_oea64 code gave up on it a long
time ago.

As a side effect, the PPC ofw_machdep code is no longer AIM-specific,
so move it to powerpc/ofw.

Centralize CPU idle routines into powerpc/cpu.c and use the same
cpu_idle_hook mechanism that x86 uses for overriding the idle routine.
This is required for supporting ilding the CPU under PowerPC hypervisors.

Add support for the IMISS, DLMISS, and DSMISS traps required to run
FreeBSD on a G2 core.

PR: powerpc/111296
Submitted by: Andrew Turner

Adjust the order of operations in spinlock_enter() and spinlock_exit() to
work properly with single-stepping in a kernel debugger. Specifically,
these routines have always disabled interrupts before increasing the nesting
count and restored the prior state of interrupts after decreasing the nesting
count to avoid problems with a nested interrupt not disabling interrupts
when acquiring a spin lock. However, trap interrupts for single-stepping
can still occur even when interrupts are disabled. Now the saved state of
interrupts is not saved in the thread until after interrupts have been
disabled and the nesting count has been increased. Similarly, the saved
state from the thread cannot be read once the nesting count has been
decreased to zero. To fix this, use temporary variables to store interrupt
state and shuffle it between the thread's MD area and the appropriate
registers.

In cooperation with: bde
MFC after: 1 month

Handle vector assist traps without a kernel panic, by setting denormalized
values to zero. A correct solution would involve emulating vector
operations on denormalized values, but this has little effect on accuracy
and is much less complicated for now.

MFC after: 2 weeks

Resurrect PSIM support by moving the cacheline size-detection warning
printf outside of the MMU-disabled region. A call into OpenFirmware
with the MMU off resulted in an internal PSIM assert.

Refactor timer management code with priority to one-shot operation mode.
The main goal of this is to generate timer interrupts only when there is
some work to do. When CPU is busy interrupts are generating at full rate
of hz + stathz to fullfill scheduler and timekeeping requirements. But
when CPU is idle, only minimum set of interrupts (down to 8 interrupts per
second per CPU now), needed to handle scheduled callouts is executed.
This allows significantly increase idle CPU sleep time, increasing effect
of static power-saving technologies. Also it should reduce host CPU load
on virtualized systems, when guest system is idle.

There is set of tunables, also available as writable sysctls, allowing to
control wanted event timer subsystem behavior:
kern.eventtimer.timer - allows to choose event timer hardware to use.
On x86 there is up to 4 different kinds of timers. Depending on whether
chosen timer is per-CPU, behavior of other options slightly differs.
kern.eventtimer.periodic - allows to choose periodic and one-shot
operation mode. In periodic mode, current timer hardware taken as the only
source of time for time events. This mode is quite alike to previous kernel
behavior. One-shot mode instead uses currently selected time counter
hardware to schedule all needed events one by one and program timer to
generate interrupt exactly in specified time. Default value depends of
chosen timer capabilities, but one-shot mode is preferred, until other is
forced by user or hardware.
kern.eventtimer.singlemul - in periodic mode specifies how much times
higher timer frequency should be, to not strictly alias hardclock() and
statclock() events. Default values are 2 and 4, but could be reduced to 1
if extra interrupts are unwanted.
kern.eventtimer.idletick - makes each CPU to receive every timer interrupt
independently of whether they busy or not. By default this options is
disabled. If chosen timer is per-CPU and runs in periodic mode, this option
has no effect - all interrupts are generating.

As soon as this patch modifies cpu_idle() on some platforms, I have also
refactored one on x86. Now it makes use of MONITOR/MWAIT instrunctions
(if supported) under high sleep/wakeup rate, as fast alternative to other
methods. It allows SMP scheduler to wake up sleeping CPUs much faster
without using IPI, significantly increasing performance on some highly
task-switching loads.

Tested by: many (on i386, amd64, sparc64 and powerc)
H/W donated by: Gheorghe Ardelean
Sponsored by: iXsystems, Inc.

Update PowerPC event timer code to use new event timers infrastructure.

Reviewed by: nwitehorn
Tested by: andreast
H/W donated by: Gheorghe Ardelean

Restructure how reset and poweroff are handled on PowerPC systems, since
the existing code was very platform specific, and broken for SMP systems
trying to reboot from KDB.

- Add a new PLATFORM_RESET() method to the platform KOBJ interface, and
migrate existing reset functions into platform modules.
- Modify the OF_reboot() routine to submit the request by hand to avoid
the IPIs involved in the regular openfirmware() routine. This fixes
reboot from KDB on SMP machines.
- Move non-KDB reset and poweroff functions on the Powermac platform
into the relevant power control drivers (cuda, pmu, smu), instead of
using them through the Open Firmware backdoor.
- Rename platform_chrp to platform_powermac since it has become
increasingly Powermac specific. When we gain support for IBM systems,
we will grow a new platform_chrp.

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.

Unify ABI-related bits of the Book-E and AIM machdep routines
(exec_setregs, etc.) in order to simplify the addition of 64-bit support,
and possible future extension of the Book-E code to handle hard floating
point and Altivec.

MFC after: 1 month

Move prototypes for kern_sigtimedwait() and kern_sigprocmask() to
<sys/syscallsubr.h> where all other kern_<syscall> prototypes live.

Change the arguments of exec_setregs() so that it receives a pointer
to the image_params struct instead of several members of that struct
individually. This makes it easier to expand its arguments in the future
without touching all platforms.

Reviewed by: jhb

Reduce KVA pressure on OEA64 systems running in bridge mode by mapping
UMA segments at their physical addresses instead of into KVA. This emulates
the direct mapping behavior of OEA32 in an ad-hoc way. To make this work
properly required sharing the entire kernel PMAP with Open Firmware, so
ofw_pmap is transformed into a stub on 64-bit CPUs.

Also implement some more tweaks to get more mileage out of our limited
amount of KVA, principally by extending KVA into segment 16 until the
beginning of the first OFW mapping.

Reported by: linimon

The first argument of dcbz interprets r0 as a literal zero, not the second.
This worked before by accident.

MFC after: 1 week

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

Turn off Altivec data-stream prefetching before going into power-save
mode on those CPUs that need it.

In r197963, a race with thread being selected for signal delivery
while in kernel mode, and later changing signal mask to block the
signal, was fixed for sigprocmask(2) and ptread_exit(3). The same race
exists for sigreturn(2), setcontext(2) and swapcontext(2) syscalls.

Use kern_sigprocmask() instead of direct manipulation of td_sigmask to
reschedule newly blocked signals, closing the race.

Reviewed by: davidxu
Tested by: pho
MFC after: 1 month

Add some more paranoia to setting HID registers, and update the AIM
clock routines to work better with SMP. This makes SMP work fully and
stably on an Xserve G5.

Obtained from: Book-E (clock bits)

Get the gdb/psim emulator functioning again.

aim/machdep.c:
- the RI status register bit needs to be set when doing the mtmsrd 64-bit
instruction test
- psim doesn't implement the dcbz instruction so the run-time cacheline
test fails. Set the cachline size to 32 to avoid infinite loops in
future calls to __syncicache()

aim/platform_chrp.c:
- if after iterating through / and a name property of "cpus" still isn't
found, just search directly for '/cpus'.
- psim doesn't put a "reg" property on it's cpu nodes, so assume 0
since it is uniprocessor-only at this point

powerpc/openpic.c
- the number of CPUs reported is 1 too many on psim's openpic

Reviewed by: nwhitehorn
MFC after: 1 week (openpic part)

Introduce support for cpufreq on PowerPC with the dynamic frequency
switching capabilities of the MPC7447A and MPC7448.

Add cpu_flush_dcache() for use after non-DMA based I/O so that a
possible future I-cache coherency operation can succeed. On ARM
for example the L1 cache can be (is) virtually mapped, which
means that any I/O that uses temporary mappings will not see the
I-cache made coherent. On ia64 a similar behaviour has been
observed. By flushing the D-cache, execution of binaries backed
by md(4) and/or NFS work reliably.
For Book-E (powerpc), execution over NFS exhibits SIGILL once in
a while as well, though cpu_flush_dcache() hasn't been implemented
yet.

Doing an explicit D-cache flush as part of the non-DMA based I/O
read operation eliminates the need to do it as part of the
I-cache coherency operation itself and as such avoids pessimizing
the DMA-based I/O read operations for which D-cache are already
flushed/invalidated. It also allows future optimizations whereby
the bcopy() followed by the D-cache flush can be integrated in a
single operation, which could be implemented using on-chips DMA
engines, by-passing the D-cache altogether.

Factor out platform dependent things unrelated to device drivers into a
new platform module. These are probed in early boot, and have the
responsibility of determining the layout of physical memory, determining
the CPU timebase frequency, and handling the zoo of SMP mechanisms
found on PowerPC.

Reviewed by: marcel, raj
Book-E parts by: raj

Zero PCB during early AIM PowerPC init.

When memory is not zero'ed by firmware, uninitialized PCB can have bogus
contents, which appear as a saved onfault condition, Altivec context to
restore etc. and lead to corruption/crashes. This commit fixes such issues.

Submitted by: Michal Mazur arg ! semihalf dot com
Tested by: Andreas Tobler andreast-list ! fgznet dot ch

Rework the way we get the cacheline size. Instead of having a table of
CPUs known to use 128 byte cache lines and defaulting to 32, use the dcbz
instruction to measure it. Also make dcbz behave the way you would
expect on PPC 970.

Fix the build when KDB is disabled. The second instance of rfi in
trap_subr.S that is patched at runtime to rfid on 64-bit systems
is inside KDB-specific code, so don't patch it without KDB.

Add support for 64-bit PowerPC CPUs operating in the 64-bit bridge mode
provided, for example, on the PowerPC 970 (G5), as well as on related CPUs
like the POWER3 and POWER4.

This also adds support for various built-in hardware found on Apple G5
hardware (e.g. the IBM CPC925 northbridge).

Reviewed by: grehan

Add Altivec support for supported CPUs. This is derived from the FPU support
code, and also reducing the size of trapcode to fit inside a 32 byte handler
slot.

Reviewed by: grehan
MFC after: 2 weeks

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

Allow the cacheline size on PowerPC to be set at runtime. This is essential for
supporting 64-bit CPUs, which often have 128-byte cache lines instead of the
standard 32.

Call powerpc_sync() instead of using an asm statement.

The VM system no longer uses setPQL2(). Remove it and its helpers.

MFp4: SMP support

- Add an integer argument to idle to indicate how likely we are to wake
from idle over the next tick.
- Add a new MD routine, cpu_wake_idle() to wakeup idle threads who are
suspended in cpu specific states. This function can fail and cause the
scheduler to fall back to another mechanism (ipi).
- Implement support for mwait in cpu_idle() on i386/amd64 machines that
support it. mwait is a higher performance way to synchronize cpus
as compared to hlt & ipis.
- Allow selecting the idle routine by name via sysctl machdep.idle. This
replaces machdep.cpu_idle_hlt. Only idle routines supported by the
current machine are permitted.

Sponsored by: Nokia

Now that all platforms use genclock, shuffle things around slightly
for better structure.

Much of this is related to <sys/clock.h>, which should really have
been called <sys/calendar.h>, but unless and until we need the name,
the repocopy can wait.

In general the kernel does not know about minutes, hours, days,
timezones, daylight savings time, leap-years and such. All that
is theoretically a matter for userland only.

Parts of kernel code does however care: badly designed filesystems
store timestamps in local time and RTC chips almost universally
track time in a YY-MM-DD HH:MM:SS format, and sometimes in local
timezone instead of UTC. For this we have <sys/clock.h>

<sys/time.h> on the other hand, deals with time_t, timeval, timespec
and so on. These know only seconds and fractions thereof.

Move inittodr() and resettodr() prototypes to <sys/time.h>.
Retain the names as it is one of the few surviving PDP/VAX references.

Move startrtclock() to <machine/clock.h> on relevant platforms, it
is a MD call between machdep.c/clock.c. Remove references to it
elsewhere.

Remove a lot of unnecessary <sys/clock.h> includes.

Move the machdep.disable_rtc_set sysctl to subr_rtc.c where it belongs.
XXX: should be kern.disable_rtc_set really, it's not MD.

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

In keeping with style(9)'s recommendations on macros, use a ';'
after each SYSINIT() macro invocation. This makes a number of
lightweight C parsers much happier with the FreeBSD kernel
source, including cflow's prcc and lxr.

MFC after: 1 month
Discussed with: imp, rink

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 :-)

Unify and generalize PowerPC headers, adjust AIM code accordingly.

Rework of this area is a pre-requirement for importing e500 support (and
other PowerPC core variations in the future). Mainly the following
headers are refactored so that we can cover for low-level differences between
various machines within PowerPC architecture:

<machine/pcpu.h>
<machine/pcb.h>
<machine/kdb.h>
<machine/hid.h>
<machine/frame.h>

Areas which use the above are adjusted and cleaned up.

Credits for this rework go to marcel@

Approved by: cognet (mentor)
MFp4: e500

Remove SMP left-overs from NetBSD.

Add a new 'why' argument to kdb_enter(), and a set of constants to use
for that argument. This will allow DDB to detect the broad category of
reason why the debugger has been entered, which it can use for the
purposes of deciding which DDB script to run.

Assign approximate why values to all current consumers of the
kdb_enter() interface.

Split decr_init() into two, with the section that reads the timebase
frequency from OpenFirmware moved out and into a routine that is called
from cpu_startup().

This allows correct reporting of the CPU clockspeed when printing out
CPU information at boot time.

Reported by: numerous
Reviewed by: marcel
MFC after: 1 day

Fix for the panic("vm_thread_new: kstack allocation failed") and
silent NULL pointer dereference in the i386 and sparc64 pmap_pinit()
when the kmem_alloc_nofault() failed to allocate address space. Both
functions now return error instead of panicing or dereferencing NULL.

As consequence, vmspace_exec() and vmspace_unshare() returns the errno
int. struct vmspace arg was added to vm_forkproc() to avoid dealing
with failed allocation when most of the fork1() job is already done.

The kernel stack for the thread is now set up in the thread_alloc(),
that itself may return NULL. Also, allocation of the first process
thread is performed in the fork1() to properly deal with stack
allocation failure. proc_linkup() is separated into proc_linkup()
called from fork1(), and proc_linkup0(), that is used to set up the
kernel process (was known as swapper).

In collaboration with: Peter Holm
Reviewed by: jhb

Revert VMCNT_* operations introduction.
Probabilly, a general approach is not the better solution here, so we should
solve the sched_lock protection problems separately.

Requested by: alc
Approved by: jeff (mentor)

Don't initialize the decrementer before initclocks() is called.
Use cpu_initclocks() for that as it assures that relevant locks
have been initialized.

- define and use VMCNT_{GET,SET,ADD,SUB,PTR} macros for manipulating
vmcnts. This can be used to abstract away pcpu details but also changes
to use atomics for all counters now. This means sched lock is no longer
responsible for protecting counts in the switch routines.

Contributed by: Attilio Rao <attilio@FreeBSD.org>

Remove the cast to caddr_t for sfp, they're not needed.

Reviewed by: marcel

Propagate the CPU model to the hw.model sysctl.

Threading cleanup.. part 2 of several.

Make part of John Birrell's KSE patch permanent..
Specifically, remove:
Any reference of the ksegrp structure. This feature was
never fully utilised and made things overly complicated.
All code in the scheduler that tried to make threaded programs
fair to unthreaded programs. Libpthread processes will already
do this to some extent and libthr processes already disable it.

Also:
Since this makes such a big change to the scheduler(s), take the opportunity
to rename some structures and elements that had to be moved anyhow.
This makes the code a lot more readable.

The ULE scheduler compiles again but I have no idea if it works.

The 4bsd scheduler still reqires a little cleaning and some functions that now do
ALMOST nothing will go away, but I thought I'd do that as a separate commit.

Tested by David Xu, and Dan Eischen using libthr and libpthread.

Make KSE a kernel option, turned on by default in all GENERIC
kernel configs except sun4v (which doesn't process signals properly
with KSE).

Reviewed by: davidxu@

Use proper trap code for the EXC_ALI traps. This fixes SIGBUS during
unaligned 64-bits load/stores.

MFC after: 2 weeks

Since DELAY() was moved, most <machine/clock.h> #includes have been
unnecessary.

Set the siginfo si_addr field, and also the mysterious 3rd parameter
to old-style signals, to be the DAR register for DSI miss exceptions.
This gives the address of the access rather than the instruction
address. The behaviour is now the same as on i386.

Found by: libsigsegv tests

MI changes:
- provide an interface (macros) to the page coloring part of the VM system,
this allows to try different coloring algorithms without the need to
touch every file [1]
- make the page queue tuning values readable: sysctl vm.stats.pagequeue
- autotuning of the page coloring values based upon the cache size instead
of options in the kernel config (disabling of the page coloring as a
kernel option is still possible)

MD changes:
- detection of the cache size: only IA32 and AMD64 (untested) contains
cache size detection code, every other arch just comes with a dummy
function (this results in the use of default values like it was the
case without the autotuning of the page coloring)
- print some more info on Intel CPU's (like we do on AMD and Transmeta
CPU's)

Note to AMD owners (IA32 and AMD64): please run "sysctl vm.stats.pagequeue"
and report if the cache* values are zero (= bug in the cache detection code)
or not.

Based upon work by: Chad David <davidc@acns.ab.ca> [1]
Reviewed by: alc, arch (in 2004)
Discussed with: alc, Chad David, arch (in 2004)

Insert a layer of indirection to the pmap code, using a kobj for
the interface. This allows run-time selection of MMU code, based
on CPU-type detection, or tunable-overrides when testing new code.

Pre-requisite for G5 support.

conf/files.powerpc
- remove pmap.c
- add mmu_if.h, mmu_oea.c, pmap_dispatch.c

powerpc/include/mmuvar.h
- definitions for MMU implementations

powerpc/include/pmap.h
- remove pmap_pte_spill declaration
- add pmap_mmu_install declaration
- size the phys_avail array
- pmap_bootstrapped is now global-scope

powerpc/powerpc/machdep.c
- call kobj_machdep_init early in the boot sequence to allow
kobj usage prior to SI_SUB_LOCK
- install the OEA pmap code. This will be moved to CPU-specific
init code in the future.

powerpc/powerpc/mmu_if.m
- Kobj MMU interface definitions

powerpc/powerpc/pmap_dispatch.c
- central dispatch for pmap calls
- contains the global mmu kobj and the routine to locate the
the mmu implementation and init the kobj

1. Change prototype of trapsignal and sendsig to use ksiginfo_t *, most
changes in MD code are trivial, before this change, trapsignal and
sendsig use discrete parameters, now they uses member fields of
ksiginfo_t structure. For sendsig, this change allows us to pass
POSIX realtime signal value to user code.

2. Remove cpu_thread_siginfo, it is no longer needed because we now always
generate ksiginfo_t data and feed it to libpthread.

3. Add p_sigqueue to proc structure to hold shared signals which were
blocked by all threads in the proc.

4. Add td_sigqueue to thread structure to hold all signals delivered to
thread.

5. i386 and amd64 now return POSIX standard si_code, other arches will
be fixed.

6. In this sigqueue implementation, pending signal set is kept as before,
an extra siginfo list holds additional siginfo_t data for signals.
kernel code uses psignal() still behavior as before, it won't be failed
even under memory pressure, only exception is when deleting a signal,
we should call sigqueue_delete to remove signal from sigqueue but
not SIGDELSET. Current there is no kernel code will deliver a signal
with additional data, so kernel should be as stable as before,
a ksiginfo can carry more information, for example, allow signal to
be delivered but throw away siginfo data if memory is not enough.
SIGKILL and SIGSTOP have fast path in sigqueue_add, because they can
not be caught or masked.
The sigqueue() syscall allows user code to queue a signal to target
process, if resource is unavailable, EAGAIN will be returned as
specification said.
Just before thread exits, signal queue memory will be freed by
sigqueue_flush.
Current, all signals are allowed to be queued, not only realtime signals.

Earlier patch reviewed by: jhb, deischen
Tested on: i386, amd64

Temporary band-aid to fix hang when a process exec's Altivec instructions.

trap_subr.S: declare a stub for the a-unavailable trap
that does an absolute jump to the vector-assist trap.
This is due to the fact that the vec-unavail trap
doesn't start at a 256-byte boundary, so the trick of
masking the bottom 8 bits of the link register to identify
the interrupt doesn't work, so let the vec-assist
case handle Altivec-disabled for the time being.

Note that this will be fixed in the future with a much
smaller vector code-stub (< 16 bytes) that will allow
use of strange vector offsets that are also present in
4xx processors, and also allow smaller differences in
vector codepaths on the G5.

trap.c: Treat altivec-unavailable/assist process traps as SIGILL.
Not quite correct, since altivec-assist should really be a panic,
but it is fine for the moment due to the above measure.

machdep.c Install the stub code for the altivec-unavailable trap, and
the standard trap code at the altivec-assist.

Reported by: Andreas Tobler <toa at pop agri ch>
MFC after: 3 days

Change an instance of md_savecrit to md_saved_msr that I missed.

Divorce critical sections from spinlocks. Critical sections as denoted by
critical_enter() and critical_exit() are now solely a mechanism for
deferring kernel preemptions. They no longer have any affect on
interrupts. This means that standalone critical sections are now very
cheap as they are simply unlocked integer increments and decrements for the
common case.

Spin mutexes now use a separate KPI implemented in MD code: spinlock_enter()
and spinlock_exit(). This KPI is responsible for providing whatever MD
guarantees are needed to ensure that a thread holding a spin lock won't
be preempted by any other code that will try to lock the same lock. For
now all archs continue to block interrupts in a "spinlock section" as they
did formerly in all critical sections. Note that I've also taken this
opportunity to push a few things into MD code rather than MI. For example,
critical_fork_exit() no longer exists. Instead, MD code ensures that new
threads have the correct state when they are created. Also, we no longer
try to fixup the idlethreads for APs in MI code. Instead, each arch sets
the initial curthread and adjusts the state of the idle thread it borrows
in order to perform the initial context switch.

This change is largely a big NOP, but the cleaner separation it provides
will allow for more efficient alternative locking schemes in other parts
of the kernel (bare critical sections rather than per-CPU spin mutexes
for per-CPU data for example).

Reviewed by: grehan, cognet, arch@, others
Tested on: i386, alpha, sparc64, powerpc, arm, possibly more

physmem is a much better indicator for 'real' memory on PPC than Maxmem
since there are often significant holes in the memory map due to the
kernel, loader and OFW data structures not being included: Maxmem is
the highest available, so can be misleading.

Catch up with "physical memory" sysctl change.
(MFi386: rev 1.608)

Catch the case where the idle loop is entered with interrupts disabled,
causing a hard hang.

- switch pcpu to a struct declaration ala amd64. It may be more efficient to
cache-align this struct, but that's a topic for a far-in-the-future
commit.
- eliminate commented-out reference to a non-existent pcpu field.

Correctly set kernelname for kern.bootfile sysctl

Noticed by: gad
Code stolen from: sparc64

Finish the job of sorting all includes and fix the build by including
malloc.h before proc.h on sparc64. Noticed by das@

Compiled on: alpha, amd64, i386, pc98, sparc64

Sort includes a little so that bus.h comes before cpu.h (for device_t).

Add an implementation of cpu_est_clockrate(9). This function estimates the
current clock frequency for the given CPU id in units of Hz.

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

Don't include sys/user.h merely for its side-effect of recursively
including other headers.

U areas are going away, so don't allocate one for process 0.

Reviewed by: arch@

Refactor a bunch of scheduler code to give basically the same behaviour
but with slightly cleaned up interfaces.

The KSE structure has become the same as the "per thread scheduler
private data" structure. In order to not make the diffs too great
one is #defined as the other at this time.

The KSE (or td_sched) structure is now allocated per thread and has no
allocation code of its own.

Concurrency for a KSEGRP is now kept track of via a simple pair of counters
rather than using KSE structures as tokens.

Since the KSE structure is different in each scheduler, kern_switch.c
is now included at the end of each scheduler. Nothing outside the
scheduler knows the contents of the KSE (aka td_sched) structure.

The fields in the ksegrp structure that are to do with the scheduler's
queueing mechanisms are now moved to the kg_sched structure.
(per ksegrp scheduler private data structure). In other words how the
scheduler queues and keeps track of threads is no-one's business except
the scheduler's. This should allow people to write experimental
schedulers with completely different internal structuring.

A scheduler call sched_set_concurrency(kg, N) has been added that
notifies teh scheduler that no more than N threads from that ksegrp
should be allowed to be on concurrently scheduled. This is also
used to enforce 'fainess' at this time so that a ksegrp with
10000 threads can not swamp a the run queue and force out a process
with 1 thread, since the current code will not set the concurrency above
NCPU, and both schedulers will not allow more than that many
onto the system run queue at a time. Each scheduler should eventualy develop
their own methods to do this now that they are effectively separated.

Rejig libthr's kernel interface to follow the same code paths as
linkse for scope system threads. This has slightly hurt libthr's performance
but I will work to recover as much of it as I can.

Thread exit code has been cleaned up greatly.
exit and exec code now transitions a process back to
'standard non-threaded mode' before taking the next step.
Reviewed by: scottl, peter
MFC after: 1 week

Implement MD parts of ptrace.

Approved by: grehan (mentor)

Improve boot-time debugging with DDB by extracting the ksym start/end
values from the loader.

Allow DSI exceptions to invoke DDB.

Properly obey PPC context synchronization rules when modifying
the address translation bits of the MSR. This fixes the boot-time
panic reported by Drew Gallatin.

Add ptrace_clear_single_step(), alpha already has it for years, the function
will be used by ptrace to clear a thread's single step state.

- DDB -> KDB, with kdb routines
- ddb -> db for low-level trapcode
- implement makectx. I think it only matters that the stack is setup
correctly.
- bring over ddb_trap_glue and rename to db_trap_glue

Kernel changes for libthr (and probably libpthread).

include/ucontext.h
- remove trapframe and switch over to 'generic' description of machine
state. Include version field to help with future modifications.
Include floating point and altivec state, and hopefully align
correctly

powerpc/copyinout.c
- fill out casuptr() sync primitive, required by kern_umtx.c

powerpc/machdep.c
- shifted proc0/thread0/pcpu setup to before cninit, since
syscons -> make_dev -> devlock requires a valid curthread
- implemented get_mcontext/set_mcontext
- recast sendsig/sigreturn to use get/set_mcontext and new
ucontext struct. floating point now saved
- TODO: save/restore altivec state

powerpc/vm_machdep.c
- implemented cpu_thread_setup/cpu_set_upcall/cpu_set_upcall_kse
- eliminated trailing whitespace

Submitted by: Suleiman Souhlal <refugee@segfaulted.com>, ucontext by grehan

Cleaned up param.h:

- culled long-dead #define's
- segment register defs moved to sr.h
- NPMAPS moved to pmap.h
- KERNBASE moved to vmparam.h
- removed include of <machine/cpu.h> and fixed src files that
relied on this.

Modifying segment register code no longer causes gcc rebuilds :-)

- remove unused trap definitions
- ISI traps are now handled by the generic trap routine
- direct diagnostic traps to DDB if defined
- remove unused asngen pcpu init

- Catch up with panic __LINE__/__FILE__ changes by moving panic calls
out of asm.
- remove some long-dead code from machdep.c

Make sigaltstack as per-threaded, because per-process sigaltstack state
is useless for threaded programs, multiple threads can not share same
stack.
The alternative signal stack is private for thread, no lock is needed,
the orignal P_ALTSTACK is now moved into td_pflags and renamed to
TDP_ALTSTACK.
For single thread or Linux clone() based threaded program, there is no
semantic changed, because those programs only have one kernel thread
in every process.

Reviewed by: deischen, dfr

Use the "shut-down" and "reset-all" Forth procedures to halt and
reboot, as calling OF_exit() just hangs a mac.

FreeBSD on my G4 800Mhz mac behaves identically to OSX for halt
and reboot now.

Reviewed by: grehan (who also supplied the concept and sample code)

Change the clear_ret argument of get_mcontext() to be a flags argument.
Since all callers either passed 0 or 1 for clear_ret, define bit 0 in
the flags for use as clear_ret. Reserve bits 1, 2 and 3 for use by MI
code for possible (but unlikely) future use. The remaining bits are for
use by MD code.

This change is triggered by a need on ia64 to have another knob for
get_mcontext().

Add a stub cpu_idle() function for sparc64, alpha, powerpc. This is a
MI declared function so it should be everywhere.

Deal with 'options KSTACK_PAGES' being a global option.

Rename thread_siginfo to cpu_thread_siginfo.

Suggested by: jhb

Add a machine depended function thread_siginfo, SA signal code
will use the function to construct a siginfo structure and use
the result to export to userland.

Reviewed by: julian

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

- Merge struct procsig with struct sigacts.
- Move struct sigacts out of the u-area and malloc() it using the
M_SUBPROC malloc bucket.
- Add a small sigacts_*() API for managing sigacts structures: sigacts_alloc(),
sigacts_free(), sigacts_copy(), sigacts_share(), and sigacts_shared().
- Remove the p_sigignore, p_sigacts, and p_sigcatch macros.
- Add a mutex to struct sigacts that protects all the members of the struct.
- Add sigacts locking.
- Remove Giant from nosys(), kill(), killpg(), and kern_sigaction() now
that sigacts is locked.
- Several in-kernel functions such as psignal(), tdsignal(), trapsignal(),
and thread_stopped() are now MP safe.

Reviewed by: arch@
Approved by: re (rwatson)

Back out last commits. The elf64/elf32 kernel name thing was more pain
than it was worth.

Fix transcription error. Use == NULL, not != NULL. Fortunately this
was harmless.

Look for an elf32 kernel (powerpc) and elf64 kernel (sparc64) as well
as a plain "elf kernel".

Add an argument to get_mcontext() which specified whether the
syscall return values should be cleared. The system calls
getcontext() and swapcontext() want to return 0 on success
but these contexts can be switched to at a later time so
the return values need to be cleared in the saved register
sets. Other callers of get_mcontext() would normally want
the context without clearing the return values.

Remove the i386-specific context saving from the KSE code.
get_mcontext() is not i386-specific any more.

Fix a bad pointer in the alpha get_mcontext() code. The
context was being bcopy()'d from &td->tf_frame, but tf_frame
is itself a pointer, so the thread was being copied instead.
Spotted by jake.

Glanced at by: jake
Reviewed by: bde (months ago)

Use __FBSDID rather than rcsid[].

- Define a new md function 'casuptr'. This atomically compares and sets
a pointer that is in user space. It will be used as the basic primitive
for a kernel supported user space lock implementation.
- Implement this function in x86's support.s
- Provide stubs that return -1 in all other architectures. Implementations
will follow along shortly.

Reviewed by: jake

- Move p->p_sigmask to td->td_sigmask. Signal masks will be per thread with
a follow on commit to kern_sig.c
- signotify() now operates on a thread since unmasked pending signals are
stored in the thread.
- PS_NEEDSIGCHK moves to TDF_NEEDSIGCHK.

Add machine check handler. While generally useful, it's required when
issuing PCI config cycles on MPC106-based PowerMacs, which cause machine
checks when accessing non-existent/empty slots.

GC an unused variable.

- Use cpu_setup() instead of identifycpu().
- Remove identifycpu().

- Rename the "powerpc" timecounter to the "decrementer" timecounter.
- Initialise it earlier.

Sync the i-cache after copying down the interrupt code

Approved by: benno

Add getcontext, setcontext, and swapcontext as system calls.
Previously these were libc functions but were requested to
be made into system calls for atomicity and to coalesce what
might be two entrances into the kernel (signal mask setting
and floating point trap) into one.

A few style nits and comments from bde are also included.

Tested on alpha by: gallatin

Print real / avail memory in megabytes rather than kilobytes.

Move the definitions of the hw.physmem, hw.usermem and hw.availpages
sysctls to MI code; this reduces code duplication and makes all of them
available on sparc64, and the latter two on powerpc.
The semantics by the i386 and pc98 hw.availpages is slightly changed:
previously, holes between ranges of available pages would be included,
while they are excluded now. The new behaviour should be more correct
and brings i386 in line with the other architectures.

Move physmem to vm/vm_init.c, where this variable is used in MI code.

Remove what was a temporary bogus assignment of bits of siginfo_t, as it does
not look like the prerequisites to fill it in properly will be in the tree
for the upcoming release, but it's mostly done, so there is no need for these
to stay around to remind us.

Split 4.x and 5.x signal handling so that we can keep 4.x signal
handling clean and functional as 5.x evolves. This allows some of the
nasty bandaids in the 5.x codepaths to be unwound.

Encapsulate 4.x signal handling under COMPAT_FREEBSD4 (there is an
anti-foot-shooting measure in place, 5.x folks need this for a while) and
finish encapsulating the older stuff under COMPAT_43. Since the ancient
stuff is required on alpha (longjmp(3) passes a 'struct osigcontext *'
to the current sigreturn(2), instead of the 'ucontext_t *' that sigreturn
is supposed to take), add a compile time check to prevent foot shooting
there too. Add uniform COMPAT_43 stubs for ia64/sparc64/powerpc.

Tested on: i386, alpha, ia64. Compiled on sparc64 (a few days ago).
Approved by: re

- implemented sendsig/sigreturn
- sysctl for cacheline size, required by libc/rtld
- init'd more exception vectors
- fixed problem with register overwrite in exec_setregs
- removed redundant NetBSD code

Approved by: benno

Allocate KSEs and KSEGRPs separatly and remove them from the proc structure.
next step is to allow > 1 to be allocated per process. This would give
multi-processor threads. (when the rest of the infrastructure is
in place)

While doing this I noticed libkvm and sys/kern/kern_proc.c:fill_kinfo_proc
are diverging more than they should.. corrective action needed soon.

Take a shot at fixing up a whole stack of style and other embarresing
unforced errors that Bruce identified. I have not yet addressed all of
his concerns.

Change hw.physmem and hw.usermem to unsigned long like they used to be
in the original hardwired sysctl implementation.

The buf size calculator still overflows an integer on machines with large
KVA (eg: ia64) where the number of pages does not fit into an int. Use
'long' there.

Change Maxmem and physmem and related variables to 'long', mostly for
completeness. Machines are not likely to overflow 'int' pages in the
near term, but then again, 640K ought to be enough for anybody. This
comes for free on 32 bit machines, so why not?

Renamed poorly named setregs to exec_setregs. Moved its prototype to
imgact.h with the other exec support functions.

Add DDB support.

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

Tidy up trap vector and external interrupt setup.

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

FPU support.

Obtained from: NetBSD (portions)

Install the system call trap handler.

GC various bits and pieces of USERCONFIG from all over the place.

GC the "dumplo" variable, which is no longer used.

A lot of sys/*/*/machdep.c seems not to be.

- Move the MI mutexes sched_lock and Giant from being declared in the
various machdep.c's to being declared in kern_mutex.c.
- Add a new function mutex_init() used to perform early initialization
needed for mutexes such as setting up thread0's contested lock list
and initializing MI mutexes. Change the various MD startup routines
to call this function instead of duplicating all the code themselves.

Tested on: alpha, i386

Add a new mtx_init option "MTX_DUPOK" which allows duplicate acquires of locks
with this flag. Remove the dup_list and dup_ok code from subr_witness. Now
we just check for the flag instead of doing string compares.

Also, switch the process lock, process group lock, and uma per cpu locks over
to this interface. The original mechanism did not work well for uma because
per cpu lock names are unique to each zone.

Approved by: jhb

Install the DSI and ISI trap handlers and their appropriate locations.

Move tunable initialisation so it can get access to physmem.

- Rearrange the sequence of events in powerpc_init() somewhat.
- Catch another instance of PSL_EE being cleared without PSL_RI.

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)

Pre-KSE/M3 commit.
this is a low-functionality change that changes the kernel to access the main
thread of a process via the linked list of threads rather than
assuming that it is embedded in the process. It IS still embeded there
but remove all teh code that assumes that in preparation for the next commit
which will actually move it out.

Reviewed by: peter@freebsd.org, gallatin@cs.duke.edu, benno rice,

Compile osigreturn() unconditionally since it will always be needed on
some arches and the syscall table is machine-independent. It was
(bogusly) conditional on COMPAT_43, so this usually makes no difference.

ia64: in addition:
- replace the bogus cloned comment before osigreturn() by a correct one.
osigreturn() is just a stub fo ia64's.
- fix the formatting of cloned comment before sigreturn().
- fix the return code. use nosys() instead of returning ENOSYS to get
the same semantics as if the syscall is not in the syscall table.
Generating SIGSYS is actually correct here.
- fix style bugs.

powerpc: copy the cleaned up ia64 stub. This mainly fixes a bogus comment.

sparc64: copy the cleaned up the ia64 stub, since there was no stub before.

Simple fixes to get the powerpc kernel compiling again.

Reviewed by: mp

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

Allow maxusers to be specified as 0 in the kernel config, which will
cause the system to auto-size to between 32 and 512 depending on the
amount of memory.

MFC after: 1 week

Don't enable FP in the kernel. It is not needed when -msoft-float is used.

Reminded by: benno

Add enable_fpu/save_fpu for handling the floating point registers in the PCB.

Obtained from: NetBSD

[partially forced commit due to pilot error in earlier commit attempt]

{set,fill}_{,fp,db}regs() fixup:

- Add dummy {set,fill}_dbregs() on architectures that don't have them.

- KSEfy the powerpc versions (struct proc -> struct thread).

- Some architectures had the prototypes in md_var.h, some in reg.h, and
some in both; for consistency, move them to reg.h on all platforms.

These functions aren't really MD (the implementation is MD, but the interface
is MI), so they should move to an MI header, but I haven't figured out which
one yet.

Run-tested on i386, build-tested on Alpha, untested on other platforms.

Fix includes based on recent changes to lock.h, mutex.h and ktr.h.

Modify a virtual address check to allow use of the openfirmware callback
used by the PowerPC simulator (PSIM).

Add a call to init_param() to initialize some necessary variables.

Catch up to recent removal of curpcb from globals.h.

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

Zap #if 0'ed map init code that got moved to the MI area.
Convert the powerpc tree to use the common code.

Make COMPAT_43 optional again. XXX we need COMPAT_FBSD3 etc for this
stuff.

Zap 'ptrace(PT_READ_U, ...)' and 'ptrace(PT_WRITE_U, ...)' since they
are a really nasty interface that should have been killed long ago
when 'ptrace(PT_[SG]ETREGS' etc came along. The entity that they
operate on (struct user) will not be around much longer since it
is part-per-process and part-per-thread in a post-KSE world.

gdb does not actually use this except for the obscure 'info udot'
command which does a hexdump of as much of the child's 'struct user'
as it can get. It carries its own #defines so it doesn't break
compiles.

Fix comment breakage.

More verbose version of identifycpu() which also contains many more CPU
versions/revisions.

Modified from the original patch to mark G3 and G4 processors as such.

Submitted by: Jeff Schottmiller <jeff@neoscale.com>

Bring in NetBSD code used in the PowerPC port.

Reviewed by: obrien, dfr
Obtained from: NetBSD