- 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 r280957

Fix integer truncation bug in malloc(9)

A couple of internal functions used by malloc(9) and uma truncated
a size_t down to an int. This could cause any number of issues
(e.g. indefinite sleeps, memory corruption) if any kernel
subsystem tried to allocate 2GB or more through malloc. zfs would
attempt such an allocation when run on a system with 2TB or more
of RAM.

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

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

- Create kern.ipc.sendfile namespace, and put the new "readhead" OID
there as "kern.ipc.sendfile.readahead".
- Push all nsfbuf related tunables into MD code. Don't move them
to new namespace in favor of POLA.

Reviewed by: scottl
Approved by: re (gjb)

Replace kernel virtual address space allocation with vmem. This provides
transparent layering and better fragmentation.

- Normalize functions that allocate memory to use kmem_*
- Those that allocate address space are named kva_*
- Those that operate on maps are named kmap_*
- Implement recursive allocation handling for kmem_arena in vmem.

Reviewed by: alc
Tested by: pho
Sponsored by: EMC / Isilon Storage Division

Introduce new structure sfstat for collecting sendfile's statistics
and remove corresponding fields from struct mbstat. Use PCPU counters
and SFSTAT_INC() macro for update these statistics.

Discussed with: glebius

Flip the semantic of M_NOWAIT to only require the allocation to not
sleep, and perform the page allocations with VM_ALLOC_SYSTEM
class. Previously, the allocation was also allowed to completely drain
the reserve of the free pages, being translated to VM_ALLOC_INTERRUPT
request class for vm_page_alloc() and similar functions.

Allow the caller of malloc* to request the 'deep drain' semantic by
providing M_USE_RESERVE flag, now translated to VM_ALLOC_INTERRUPT
class. Previously, it resulted in less aggressive VM_ALLOC_SYSTEM
allocation class.

Centralize the translation of the M_* malloc(9) flags in the single
inline function malloc2vm_flags().

Discussion started by: "Sears, Steven" <Steven.Sears@netapp.com>
Reviewed by: alc, mdf (previous version)
Tested by: pho (previous version)
MFC after: 2 weeks

Eliminate vestiges of page coloring.

Fix OF_finddevice error return value in case of FDT.

According to the open firmware standard, finddevice call has to return
a phandle with value of -1 in case of error.

This commit is to:
- Fix the FDT implementation of this interface (ofw_fdt_finddevice) to
return (phandle_t)-1 in case of error, instead of 0 as it does now.
- Fix up the callers of OF_finddevice() to compare the return value with
-1 instead of 0 to check for errors.
- Since phandle_t is unsigned, the return value of OF_finddevice should
be checked with '== -1' rather than '<= 0' or '> 0', fix up these cases
as well.

Reported by: nwhitehorn

Reviewed by: raj
Approved by: raj, nwhitehorn

It can be useful to know which page still has mappings.

Remove the advertising clause from the UCB license according to the
July 22, 1999 addendum.

For architectures not using direct map , and requiring real KVA page for
sf buf allocation, use wakeup() instead of wakeup_one() to notify sf
buffer waiters about free buffer.

sf_buf_alloc() calls msleep(PCATCH) when SFB_CATCH flag was given,
and for simultaneous wakeup and signal delivery, msleep() returns
EINTR/ERESTART despite the thread was selected for wakeup_one(). As
result, we loose a wakeup, and some other waiter will not be woken up.

Reported and tested by: az
Reviewed by: alc, jhb
MFC after: 1 week

Remove unneeded includes of <sys/linker_set.h>. Other headers that use
it internally contain nested includes.

Reviewed by: bde

- Update the comment in swi_vm() regarding busdma bounce buffers; it's
unlikely that support for these ever will be implemented on sparc64 as
the IOMMUs are able to translate to up to the maximum physical address
supported by the respective machine, bypassing the IOMMU is affected
by hardware errata and being able to support DMA engines which cannot
do at least 32-bit DMA does not justify the costs.
- The page zeroing in uma_small_alloc() may use the VIS-based block zero
function so take advantage of it.

For CPUs which ignore TD_CV and support hardware unaliasing don't
bother doing page coloring. This results in a small but measurable
performance improvement in buildworld times.

Extract the code that records syscall results in the frame into MD
function cpu_set_syscall_retval().

Suggested by: marcel
Reviewed by: marcel, davidxu
PowerPC, ARM, ia64 changes: marcel
Sparc64 tested and reviewed by: marius, also sunv reviewed
MIPS tested by: gonzo
MFC after: 1 month

Just like in cpu_halt(), use cpu_shutdown() rather than ofw_exit()
directly in cpu_reset() in order to idle the APs before exiting
the kernel and letting the BSP enter the firmware so that processes
like init(8) which still might be running on an AP at that point
don't cause a panic there when it crashes due to the fact it no
longer can be supported by the kernel.

MFC after: 3 days

- Fix style.
- Use __FBSDID.

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

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

o Rename cpu_thread_setup() to cpu_thread_alloc() to better
communicate that it relates to (is called by) thread_alloc()
o Add cpu_thread_free() which is called from thread_free()
to counter-act cpu_thread_alloc().

i386: Have cpu_thread_free() call cpu_thread_clean() to
preserve behaviour.
ia64: Have cpu_thread_free() call mtx_destroy() for the
mutex initialized in cpu_thread_alloc().

PR: ia64/118024

It has been observed on the mailing lists that the different categories
of pages don't sum to anywhere near the total number of pages on amd64.
This is for the most part because uma_small_alloc() pages have never been
counted as wired pages, like their kmem_malloc() brethren. They should
be. This changes fixes that.

It is no longer necessary for the page queues lock to be held to free
pages allocated by uma_small_alloc(). I removed the acquisition and
release of the page queues lock from uma_small_free() on amd64 and ia64
weeks ago. This patch updates the other architectures that have
uma_small_alloc() and uma_small_free().

Approved by: re (kensmith)

- Change comments and asserts to reflect the removal of the global
scheduler lock.

Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)

Validate if the value written into {FS,GS}.base is a canonical
address, writting non-canonical address can cause kernel a panic,
by restricting base values to 0..VM_MAXUSER_ADDRESS, ensuring
only canonical values get written to the registers.

Reviewed by: peter, Josepha Koshy < joseph.koshy at gmail dot com >
Approved by: re (scottl)

Change cpu_set_kse_upcall to more generic style, so we can reuse it
in other codes. Add cpu_set_user_tls, use it to tweak user register
and setup user TLS. I ever wanted to merge it into cpu_set_kse_upcall,
but since cpu_set_kse_upcall is also used by M:N threads which may
not need this feature, so I wrote a separated cpu_set_user_tls.

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

Add a small API to manage the MD user trap structures. Specifically, we
now use a pool mutex to manage the reference counts. This fixes races
resulting in use-after-free.

Tested by: kris, David Cornejo dave at dogwood dot com
Reported by: bmilekic's MemGuard
MFC after: 1 week

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

Correct a typo in the previous revision.

Introduce two new options, "CPU private" and "no wait", to sf_buf_alloc().
Change the spelling of the "catch" option to be consistent with the new
options. Implement the "no wait" option. An implementation of the "CPU
private" for i386 will be committed at a later date.

Initialize the count of saved register windows to 0 in the pcb created
for the new thread. The rest of the fields in the pcb wind up being
written to before they're read as a normal part of the pcb usage but
this field may be read upon return to userland, having it be uninitialized
garbage is bad.

Submitted by: Andrew Belashov (bel at orel dot ru)
Reviewed by: jake
MFC after: 3 days

Bring in mbuma to replace mballoc.

mbuma is an Mbuf & Cluster allocator built on top of a number of
extensions to the UMA framework, all included herein.

Extensions to UMA worth noting:
- Better layering between slab <-> zone caches; introduce
Keg structure which splits off slab cache away from the
zone structure and allows multiple zones to be stacked
on top of a single Keg (single type of slab cache);
perhaps we should look into defining a subset API on
top of the Keg for special use by malloc(9),
for example.
- UMA_ZONE_REFCNT zones can now be added, and reference
counters automagically allocated for them within the end
of the associated slab structures. uma_find_refcnt()
does a kextract to fetch the slab struct reference from
the underlying page, and lookup the corresponding refcnt.

mbuma things worth noting:
- integrates mbuf & cluster allocations with extended UMA
and provides caches for commonly-allocated items; defines
several zones (two primary, one secondary) and two kegs.
- change up certain code paths that always used to do:
m_get() + m_clget() to instead just use m_getcl() and
try to take advantage of the newly defined secondary
Packet zone.
- netstat(1) and systat(1) quickly hacked up to do basic
stat reporting but additional stats work needs to be
done once some other details within UMA have been taken
care of and it becomes clearer to how stats will work
within the modified framework.

From the user perspective, one implication is that the
NMBCLUSTERS compile-time option is no longer used. The
maximum number of clusters is still capped off according
to maxusers, but it can be made unlimited by setting
the kern.ipc.nmbclusters boot-time tunable to zero.
Work should be done to write an appropriate sysctl
handler allowing dynamic tuning of kern.ipc.nmbclusters
at runtime.

Additional things worth noting/known issues (READ):
- One report of 'ips' (ServeRAID) driver acting really
slow in conjunction with mbuma. Need more data.
Latest report is that ips is equally sucking with
and without mbuma.
- Giant leak in NFS code sometimes occurs, can't
reproduce but currently analyzing; brueffer is
able to reproduce but THIS IS NOT an mbuma-specific
problem and currently occurs even WITHOUT mbuma.
- Issues in network locking: there is at least one
code path in the rip code where one or more locks
are acquired and we end up in m_prepend() with
M_WAITOK, which causes WITNESS to whine from within
UMA. Current temporary solution: force all UMA
allocations to be M_NOWAIT from within UMA for now
to avoid deadlocks unless WITNESS is defined and we
can determine with certainty that we're not holding
any locks when we're M_WAITOK.
- I've seen at least one weird socketbuffer empty-but-
mbuf-still-attached panic. I don't believe this
to be related to mbuma but please keep your eyes
open, turn on debugging, and capture crash dumps.

This change removes more code than it adds.

A paper is available detailing the change and considering
various performance issues, it was presented at BSDCan2004:
http://www.unixdaemons.com/~bmilekic/netbuf_bmilekic.pdf
Please read the paper for Future Work and implementation
details, as well as credits.

Testing and Debugging:
rwatson,
brueffer,
Ketrien I. Saihr-Kesenchedra,
...
Reviewed by: Lots of people (for different parts)

Retire cpu_sched_exit(); it is not used any more.

Move the per-CPU vmspace pointer fixup that is required before a
struct vmspace is freed from cpu_sched_exit() to pmap_release().

This has the advantage of being able to rely on MI code to decide
when a free should occur, instead of having to inspect the reference
count ourselves.

At the same time, turn the per-CPU vmspace pointer into a pmap pointer,
so that pmap_release() can deal with pmaps exclusively.

Reviewed (and embrassing bug spotted) by: jake

In cpu_sched_exit(), we must check vm_refcnt against 0, not 1, since
exit1() decrements the reference count before calling this function.

In some cases, sf_buf_alloc() should sleep with pri PCATCH; in others, it
should not. Add a new parameter so that the caller can specify which is
the case.

Reported by: dillon

MFi386: correctly calculate the top-of-stack when a kthread is created
with a larger kernel stack. Remove inclusion of opt_kstack_pages.h now
that it's unused.

Reviewed by: marcel
Approved by: rwatson (mentor)

Intitialize the frame pointer and return pc of a new process created
in cpu_fork(). This prevents the stack tracer from running past the
end of the stack (only the pc is checked in that case), which became
fatal when db_print_backtrace() was introduced and called outside
of ddb.

Additional testing: kris

Refactor the existing machine-dependent sf_buf_free() into a machine-
dependent function by the same name and a machine-independent function,
sf_buf_mext(). Aside from the virtue of making more of the code machine-
independent, this change also makes the interface more logical. Before,
sf_buf_free() did more than simply undo an sf_buf_alloc(); it also
unwired and if necessary freed the page. That is now the purpose of
sf_buf_mext(). Thus, sf_buf_alloc() and sf_buf_free() can now be used
as a general-purpose emphemeral map cache.

Track three new sendfile-related statistics:
- The number of times sendfile had to do disk I/O
- The number of times sfbuf allocation failed
- The number of times sfbuf allocation had to wait

Move the declaration of sfbufspeak and sfbufsused to mbuf.h,
and use imax instead of max, as sfbufspeak and sfbufsused
are signed.

Submitted by: bde

Track current and peak sfbuf usage, export the values via sysctl.

- Remove unnecessary synchronization from sf_buf_init(). (There is only
one active CPU when sf_buf_init() is performed.)

- Modify alpha's sf_buf implementation to use the direct virtual-to-
physical mapping.
- Move the sf_buf API to its own header file; make struct sf_buf's
definition machine dependent. In this commit, we remove an
unnecessary field from struct sf_buf on the alpha, amd64, and ia64.
Ultimately, we may eliminate struct sf_buf on those architecures
except as an opaque pointer that references a vm page.

Preparatory commit to allow prototypes in ofw_machdep.h to contain
both newbus types and OFW types. This involves either including
<machine/bus.h> or <dev/ofw/openfirm.h>.

Reviewed by: jake, jmg, tmm

Implement cpu_set_upcall_kse. May need tweaking.

Migrate the sf_buf allocator that is used by sendfile(2) and zero-copy
sockets into machine-dependent files. The rationale for this
migration is illustrated by the modified amd64 allocator. It uses the
amd64's direct map to avoid emphemeral mappings in the kernel's
address space. On an SMP, the emphemeral mappings result in an IPI
for TLB shootdown for each transmitted page. Yuck.

Maintainers of other 64-bit platforms with direct maps should be able
to use the amd64 allocator as a reference implementation.

In vm_thread_swap{in|out}(), remove the alpha specific conditional
compilation and replace it with a call to cpu_thread_swap{in|out}().
This allows us to add similar code on ia64 without cluttering the
code even more.

Deal with 'options KSTACK_PAGES' being a global option.

Fix a performance bug in all of the various implementations of
uma_small_alloc(): They always zeroed the page regardless of what the
caller requested.

GC unused cpu_wait() function

- Declare sparc64_memreg and sparc64_nmemreg in machine/ofw_mem.h.
- On startup print the total physical memory, instead of what we're told is
free by the firmware, to avoid astonishing users.

Change the second (and last) argument of cpu_set_upcall(). Previously
we were passing in a void* representing the PCB of the parent thread.
Now we pass a pointer to the parent thread itself.
The prime reason for this change is to allow cpu_set_upcall() to copy
(parts of) the trapframe instead of having it done in MI code in each
caller of cpu_set_upcall(). Copying the trapframe cannot always be
done with a simply bcopy() or may not always be optimal that way. On
ia64 specifically the trapframe contains information that is specific
to an entry into the kernel and can only be used by the corresponding
exit from the kernel. A trapframe copied verbatim from another frame
is in most cases useless without some additional normalization.

Note that this change removes the assignment to td->td_frame in some
implementations of cpu_set_upcall(). The assignment is redundant.
A previous call to cpu_thread_setup() already did the exact same
assignment. An added benefit of removing the redundant assignment is
that we can now change td_pcb without nasty side-effects.

This change officially marks the ability on ia64 for 1:1 threading.

Not tested on: amd64, powerpc
Compile & boot tested on: alpha, sparc64
Functionally tested on: i386, ia64

Use vm_paddr_t for physical addresses.

Implement cpu_thread_setup. Fix cpu_set_upcall.

Implement cpu_set_upcall.

- Rename pcb_fpstate to pcb_ufp (user floating point), and change it to
a simple array of 64 ints.
- Use a critical section when saving floating point state in cpu_fork
instead of sched_lock.

Rename pcb_fp to pcb_sp, so as to not be confused with floating point
state.

Implement is_physical_memory. Accessing memory which doesn't exist causes
traps that are difficult to recover from, so we check against the memory
map returned by the prom.

- Split the struct kse into struct upcall and struct kse. struct kse will
soon be visible only to schedulers. This greatly simplifies much the
KSE code.

Submitted by: davidxu

Reversion of commit by Davidxu plus fixes since applied.

I'm not convinced there is anything major wrong with the patch but
them's the rules..

I am using my "David's mentor" hat to revert this as he's
offline for a while.

Move UPCALL related data structure out of kse, introduce a new
data structure called kse_upcall to manage UPCALL. All KSE binding
and loaning code are gone.

A thread owns an upcall can collect all completed syscall contexts in
its ksegrp, turn itself into UPCALL mode, and takes those contexts back
to userland. Any thread without upcall structure has to export their
contexts and exit at user boundary.

Any thread running in user mode owns an upcall structure, when it enters
kernel, if the kse mailbox's current thread pointer is not NULL, then
when the thread is blocked in kernel, a new UPCALL thread is created and
the upcall structure is transfered to the new UPCALL thread. if the kse
mailbox's current thread pointer is NULL, then when a thread is blocked
in kernel, no UPCALL thread will be created.

Each upcall always has an owner thread. Userland can remove an upcall by
calling kse_exit, when all upcalls in ksegrp are removed, the group is
atomatically shutdown. An upcall owner thread also exits when process is
in exiting state. when an owner thread exits, the upcall it owns is also
removed.

KSE is a pure scheduler entity. it represents a virtual cpu. when a thread
is running, it always has a KSE associated with it. scheduler is free to
assign a KSE to thread according thread priority, if thread priority is changed,
KSE can be moved from one thread to another.

When a ksegrp is created, there is always N KSEs created in the group. the
N is the number of physical cpu in the current system. This makes it is
possible that even an userland UTS is single CPU safe, threads in kernel still
can execute on different cpu in parallel. Userland calls kse_create to add more
upcall structures into ksegrp to increase concurrent in userland itself, kernel
is not restricted by number of upcalls userland provides.

The code hasn't been tested under SMP by author due to lack of hardware.

Reviewed by: julian

- Add a VM_WAIT in the appropriate cases where vm_page_alloc() fails and flags
indicate that uma_small_alloc should not. This code should be refactored so
that there is not so much cross arch duplication.

Reviewed by: jake
Spotted by: tmm
Tested on: alpha, sparc64
Pointy hat to: jeff and everyone who cut and pasted the bad code. :-)

Merge all the various copies of vm_fault_quick() into a single
portable copy.

Merge all the various copies of vmapbuf() and vunmapbuf() into a single
portable copy. Note that pmap_extract() must be used instead of
pmap_kextract().

This is precursor work to a reorganization of vmapbuf() to close remaining
user/kernel races (which can lead to a panic).

- Reorganize PMAP_STATS to scale a little better.
- Add some more stats for things that are now considered interesting.

Implement uma_small_alloc and uma_small_free. Not yet used.

Unbreak the KSE code. Keep track of zobie threads using the Per-CPU storage
during the context switch. Rearrange thread cleanups
to avoid problems with Giant. Clean threads when freed or
when recycled.

Approved by: re (jhb)

Add page queues locking to vunmapbuf().

Approved by: re (blanket)

Under certain circumstances, we were calling kmem_free() from
i386 cpu_thread_exit(). This resulted in a panic with WITNESS
since we need to hold Giant to call kmem_free(), and we weren't
helding it anymore in cpu_thread_exit(). We now do this from a
new MD function, cpu_thread_dtor(), called by thread_dtor().

Approved by: re@
Suggested by: jhb

Fix standard kse breakge of non-x86 platforms. sigh.

Pointy hat to: kse

Part 1 of KSE-III

The ability to schedule multiple threads per process
(one one cpu) by making ALL system calls optionally asynchronous.
to come: ia64 and power-pc patches, patches for gdb, test program (in tools)

Reviewed by: Almost everyone who counts
(at various times, peter, jhb, matt, alfred, mini, bernd,
and a cast of thousands)

NOTE: this is still Beta code, and contains lots of debugging stuff.
expect slight instability in signals..

Add an MD callout like cpu_exit, but which is called after sched_lock is
obtained, when all other scheduling activity is suspended. This is needed
on sparc64 to deactivate the vmspace of the exiting process on all cpus.
Otherwise if another unrelated process gets the exact same vmspace structure
allocated to it (same address), its address space will not be activated
properly. This seems to fix some spontaneous signal 11 problems with smp
on sparc64.

Don't try to flush illegal alises from the data cache in vmapbuf and
vunmapbuf, this is handled by pmap now.

Add support for an alternate signal trampoline; add a sysarch call to register
an alternate trampoling with the kernel.

Rename some fields in struct frame to be compatible with NetBSD/OpenBSD,
and add some compatibility defines. Add fields for ins and locals to
struct reg also for the same reason; these aren't filled in yet because
getting at those registers sucks and I'd rather not save them in the
trapframe just for this. Reorder struct reg to be ABI compatible as
well. Add needed include of machine/emul.h.

This gets pmdb (poor man's debugger) from OpenBSD mostly compiling but it
doesn't work yet :(

Fix obscure problems with vfork where part of the parent's stack could be
clobbered by the child. This is more complicated than usual because the
window that could get clobbered is pushed in kernel mode, so a lot of
registers would have to be saved in other registers in userland and we
don't have enough. What we do have is space in the pcb to temporarily
store user windows that were spilled in kernel mode, but could not be
immediately stored to the user stack. So we copy in the parent's topmost
window and save it in the pcb, and arrange for it to be copied back out
when the child is done frobbing the stack.

Reviewed by: tmm

Minor cleanup.

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,

Use cpufunc macros instead of using inline asm directly.

Implement user trap delivery as specified by the sparc abi. This provides
an efficient way for the kernel to bounce certain mundane traps back to
userland for handling there. A user trap handler returns directly to the
trapping user code, rather than going through the kernel again. Only a
handful of instructions are actually executed in kernel mode.
Implement sysarch(SPARC_UTRAP_INSTALL).
Add code to handle sharing of the user trap table across forks and unsharing
at exec.

This can be used to implement efficient tracking of floating point register
usage in userland, fe by a thread library, and to handle alignment fault
fixups and instruction emulation in userland, for which the code may need
to be different for 32bit and 64bit binaries.

Add needed include of fsr.h.
Use fprs to track floating point usage.
Remove misguided comment.
Clear fprs in a child process's new trapframe.

1. Convert the tstate saved in the pcb to a pstate and test for PSTATE_PEF
to determine if a process is using floating point. in order to avoid
sign extending a 13 bit immediate.
2. We don't need to context switch cwp anymore, it is better to just
fiddle the save tstate on return from traps. See exception.s 1.10
and 1.12.
3. Completely remove pcb_cwp.
4. Implement vmapbuf, vunmapbuf and vm_fault_quick. Completely remove
TODOs from vm_machdep.c (yay!).

Submitted by: tmm (1, 3, 4)
Obtained from: existing archs (4)

Add a special OpenFirmware entry point for terminating the kernel (in
this case, the firmware trap table needs to be restored). Make use of
it in cpu_halt() and cpu_reset(), and make cpu_reset() reboot the kernel
that was used previously insead of behaving like cpu_halt().
Add a shutdown_final event handler that turns the power off if requested.

Remove hardcoded cwp value.

Save the floating point context to the right pcb in cpu_fork(), and add
an empty stub for is_physical_memory().

Move the pcb the to the top of the kernel stack.
Add a guard page at the bottom of the kernel stack. Its unclear how easy
it will be to detect these faults and do something useful.
Setup the registers on exec how the c runtime expects.
Implement various {fill,set}_*regs.
Fix proc locking.

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

Rip some well duplicated code out of cpu_wait() and cpu_exit() and move
it to the MI area. KSE touched cpu_wait() which had the same change
replicated five ways for each platform. Now it can just do it once.
The only MD parts seemed to be dealing with fpu state cleanup and things
like vm86 cleanup on x86. The rest was identical.

XXX: ia64 and powerpc did not have cpu_throw(), so I've put a functional
stub in place.

Reviewed by: jake, tmm, dillon

Add comments following what other architectures have.

Fiddle the register values in the trapframe so children returning from
fork() return 0 (and success).

Handle the pcb window scratch area in cpu_fork.
Implement cpu_exit.

Submitted by: tmm

Implement cpu_wait().

Fake up the frame pointers on a process's initial stack so they can be
restored correctly from the trapframe.

Submitted by: tmm

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

Add floating point context switching code for sparc64.

Reviewed by: jake

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