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

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

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

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

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

Fix a typo in a comment.

Rename device vfp to option VFP and retire the ARM_VFP_SUPPORT option. This
simplifies enabling as previously both options were required to be enabled,
now we only need a single option.

While here enable VFP on the PandaBoard.

Add the hw.floatingpoint sysctl to ARM to tell us if we have vfp support
in the kernel and the hardware includes a vfp unit.

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

Add basic and not very reliable protection against going to sleep with
thread scheduled by interrupt fired after we entered critical section.
None of cpu_sleep() implementations on ARM check sched_runnable() now, so
put the first line of defence here. This mostly fixes unexpectedly long
sleeps in synthetic tests of calloutng code and probably other situations.

Initialize vm_max_kernel_address on non-FDT platforms. (This should have
been included in r246926.)

The second parameter to pmap_bootstrap() is redundant. Eliminate it.

Reviewed by: andrew

On arm, like sparc64, the end of the kernel map varies from one type of
machine to another. Therefore, VM_MAX_KERNEL_ADDRESS can't be a constant.
Instead, #define it to be a variable, vm_max_kernel_address, just like we
do on sparc64.

Reviewed by: kib
Tested by: ian

Eliminate the need for an intermediate array of indices into the arrays of
interrupt counts and names, by making the names into an array of fixed-length
strings that can be directly indexed. This eliminates extra memory accesses
on every interrupt to increment the counts.

As a side effect, it also fixes a bug that would corrupt the names data
if a name was longer than MAXCOMLEN, which led to incorrect vmstat -i output.

Approved by: cognet (mentor)

Add hw.board.serial and hw.board.revision for exporting board-specific info

Get reserved memory regions and exclude them from available memory map

Remove print_kernel_section_addr(). All statements in that function
expand to uncompilable code when the kernel configuration contains
"options DEBUG", such as it is for LINT. The toolchain is often a
better approach to figure this out, as it doesn't require one to
boot the kernel.

Reduce differences between these two initarms a bit more.

Minor cosmetic changes to bring atmel's initarm and the default
initarm for FDT closer together. More to follow.

Merge the FDT versions of initarm.

The copies of initarm used on platforms with FDT support were almost
identical. The differences were pulled out into separate functions that
were called by initarm.

This change merges the, now identical, copies of initarm and a few of it's
support functions. This is a step towards a common kernel on ARMv6.

Create a common set_stackptrs in sys/arm/machdep.c.

On single core devices set_stackptrs is only ever called with cpu = 0 in
initarm and will be identical to the existing function. On SMP this needs
to be implemented for sys/arm/mp_machdep.c, but the implementations are
identical for each SoC.

Call set_pcpu for ARMv6 architecture too

Merging projects/armv6, part 1

Cummulative patch of changes that are not vendor-specific:
- ARMv6 and ARMv7 architecture support
- ARM SMP support
- VFP/Neon support
- ARM Generic Interrupt Controller driver
- Simplification of startup code for all platforms

Fix a global shadowing problem when LINUX_BOOT_ABI was defined.

More Linux boot support. Create arm_dump_avail_init() to initialize
this array either from Linux boot data, when enabled, or in the
typical way that most ports do it. arm_pyhs_avail_init is coming
soon since it must be a separate function.

Add support for parsing Linux ATAGs such as you'd see from uboot or
redboot. Support is very preiminary and likely needs some work. Also,
do some minor code shuffling of the FreeBSD /boot/loader metadata
parsing code. This code is preliminary and should be used with
caution.

Create default_parse_boot_param which, if FreeBSD /boot/loader support
is enabled, sets values based on the metadata passed in. Otherwise
fake_preload_metadata is called. Change the default parse_boot_param
to default_parse_boot_param. Enable this functionality only on the mv
platform, which is where most of the code is from.

Reviewed by: cognet, Ian Lapore

Modify all the arm platform files to call parse_boot_param passing in
the boot parameters from initarm first thing. parse_boot_param parses
the boot arguments and converts them to the /boot/loader metadata the
rest of the kernel uses. parse_boot_param is a weak alias to
fake_preload_metadata, which all the platforms use now, but may become
more extensive in the future.

Since it is a weak symbol, specific boards may define their own
parse_boot_param to interface to custom boot loaders.

Reviewed by: cognet@, Ian Lapore

Final whitespace trim.

Pull out the common code to initialise proc0 & thread0 from initarm to a
common function.

Reviewed by: imp

Soft PMC support for ARM.
Callgraph is not captured, only current location.

Sample system wide profiling: "pmcstat -Sclock.hard -T"

TDF_* flags should be used with td_flags field and TDP_* flags should be used
with td_pflags field. Correct two places where it was not the case.

Discussed with: kib
MFC after: 1 week

Explicitely set ARM_RAS_START and ARM_RAS_END once the cacheline or the
page has been allocated, or we could end up using random values, and bad things
could happen.

PR: arm/161492
Submitted by: Ian Lepore <freebsd AT damnhippie dot dyndns DOT org>
MFC after: 1 week

In order to maximize the re-usability of kernel code in user space this
patch modifies makesyscalls.sh to prefix all of the non-compatibility
calls (e.g. not linux_, freebsd32_) with sys_ and updates the kernel
entry points and all places in the code that use them. It also
fixes an additional name space collision between the kernel function
psignal and the libc function of the same name by renaming the kernel
psignal kern_psignal(). By introducing this change now we will ease future
MFCs that change syscalls.

Reviewed by: rwatson
Approved by: re (bz)

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

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

Eliminate an unnecessary vm include file.

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 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.

Do not set thread0.td_frame to a bogus value, as it's going to overwrite the
thread0 pcb, while the board-dependant code already set a good trapframe.

Reported by: Mark Tinguely <tinguely at casselton d0t net>

MFC after: 1 week

- 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

Take the first baby step towards unifying and cleaning up arminit():
- Pull all the code to deal with the trampoline stuff into one
centeralized place and use it from everywhere.
- Some minor style tidiness

Reviewed by: tinguely

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

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)

Constify to please gcc 4.2.

- 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>

Add KTR tracing

In sendsig:

- Add sigacts locking.
- Add a mutex to struct sigacts that protects all the members of the struct.
- Create and log events via the CTRx macros.

Reviewed by: cognet

Display real/avail memory as per other platforms.

Approved by: cognet

Move the call to cpu_setup() before the call to vm_ksubmap_init().
vm_ksubmap_init() calls pmap_copy_page(), which uses the mini data cache
to do the copy, but we're running uncaching before cpu_setup().
For some reason it hasn't been a problem so far, but it is for the
PXA255.

Spotted out by: benno

Close some races between procfs/ptrace and exit(2):
- Reorder the events in exit(2) slightly so that we trigger the S_EXIT
stop event earlier. After we have signalled that, we set P_WEXIT and
then wait for any processes with a hold on the vmspace via PHOLD to
release it. PHOLD now KASSERT()'s that P_WEXIT is clear when it is
invoked, and PRELE now does a wakeup if P_WEXIT is set and p_lock drops
to zero.
- Change proc_rwmem() to require that the processing read from has its
vmspace held via PHOLD by the caller and get rid of all the junk to
screw around with the vmspace reference count as we no longer need it.
- In ptrace() and pseudofs(), treat a process with P_WEXIT set as if it
doesn't exist.
- Only do one PHOLD in kern_ptrace() now, and do it earlier so it covers
FIX_SSTEP() (since on alpha at least this can end up calling proc_rwmem()
to clear an earlier single-step simualted via a breakpoint). We only
do one to avoid races. Also, by making the EINVAL error for unknown
requests be part of the default: case in the switch, the various
switch cases can now just break out to return which removes a _lot_ of
duplicated PRELE and proc unlocks, etc. Also, it fixes at least one bug
where a LWP ptrace command could return EINVAL with the proc lock still
held.
- Changed the locking for ptrace_single_step(), ptrace_set_pc(), and
ptrace_clear_single_step() to always be called with the proc lock
held (it was a mixed bag previously). Alpha and arm have to drop
the lock while the mess around with breakpoints, but other archs
avoid extra lock release/acquires in ptrace(). I did have to fix a
couple of other consumers in kern_kse and a few other places to
hold the proc lock and PHOLD.

Tested by: ps (1 mostly, but some bits of 2-4 as well)
MFC after: 1 week

Add missing "struct" in i386/i386/machdep.c,v 1.497 by deischen@.

MFi386 rev 1.536 (sort of)
Move what can be moved (UMA zones creation, pv_entry_* initialization) from
pmap_init2() to pmap_init().
Create a new function, pmap_postinit(), called from cpu_startup(), to do the
L1 tables allocation.
pmap_init2() is now empty for arm as well.

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

Export the variables needed for the copy/zero API.

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

Introduce realmem.

Instead of using sysarch() to store-retrieve the tp, add a magic address,
ARM_TP_ADDRESS, where the tp will be stored. On CPUs that support it, a cache
line will be allocated and locked for this address, so that it will never go
to RAM. On CPUs that does not, a page is allocated for it (it will be a bit
slower, and is wrong for SMP, but should be fine for UP).
The tp is still stored in the mdthread struct, and at each context switch,
ARM_TP_ADDRESS gets updated.

Suggested by: davidxu

move pmap.h after vm.h include... some of the headers from pmap.h depend
upon vm.h

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.

Add support for ptrace() and gdb breakpoints.

Start all license statements with /*-

Implement cpu_thread_siginfo() and set_mcontext().
Nuke getframe(), and choose which stack to use directly in sendsig().

Implement sigreturn().

Don't use cast as lvalue.

Implement ptrace_set_pc().
Add a stub for ptrace_clear_single_step().

Remove astpending, it has not been used for a long time.

Implement makectx().

Import FreeBSD/arm kernel bits.
It only supports sa1110 (on simics) right now, but xscale support should come
soon.
Some of the initial work has been provided by :
Stephane Potvin <sepotvin at videotron.ca>
Most of this comes from NetBSD.