Now that the PUSHFRAME and PULLFRAME macros are used only in the swi
entry/exit code, they don't need to be macros. Now they're just inline
code, and rewritten to use shorter instruction sequences.

Arrange for arm fork_trampoline() to return to userland via the standard
swi_exit code in exception.S instead of having its own inline expansion
of the DO_AST and PULLFRAME macros. That means that n

Arrange for arm fork_trampoline() to return to userland via the standard
swi_exit code in exception.S instead of having its own inline expansion
of the DO_AST and PULLFRAME macros. That means that now all references
to the PUSH/PULLFRAME and DO_AST macros are localized to exception.S,
so move the macros themselves into there and remove them from asmacros.h

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Change the way the asm GET_CURTHREAD_PTR() macro is defined so that code
using it doesn't have to have an "AST_LOCALS" macro somewhere in the file.

Move the exception vector table (so-called "page0" data) into exception.S
and eliminate vectors.S. All low-level exception handling is now
consolidated into exception.S.

Along with moving the defau

Move the exception vector table (so-called "page0" data) into exception.S
and eliminate vectors.S. All low-level exception handling is now
consolidated into exception.S.

Along with moving the default FIQ handler, change it to disable FIQs
before returning. An FIQ should never happen, but if it does, it's got
to be disabled as part of ignoring it.

In general, we have hand-wavy support for FIQs that probably hasn't been
used for 10 years and probably doesn't work (almost certainly doesn't
work for SMP because it only updates the vector on the current cpu). This
change doesn't really make the overall situation any better or worse.

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Eliminate irq_dispatch.S. Move the data items it contained into arm/intr.c
and the functionality it provided into arm/exception.S. Rename the main
irq handling routine from arm_handler_execute() to

Eliminate irq_dispatch.S. Move the data items it contained into arm/intr.c
and the functionality it provided into arm/exception.S. Rename the main
irq handling routine from arm_handler_execute() to arm_irq_handler() to
make it more congruent with how other exception handlers are named, and
also update its signature to reflect what has long been reality: it is
passed just a trapframe pointer, no interrupt number argument.

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Make the default exception handler vectors point to where I thought they
were already pointing: the default handlers (not a panic that says there
is no default handler).

Make undefined exception entry MPSAFE.

The old code used static storage to preserve a couple registers while
setting up the trapframe for the main handler. Doing so was the last
leftover crumbs fro

Make undefined exception entry MPSAFE.

The old code used static storage to preserve a couple registers while
setting up the trapframe for the main handler. Doing so was the last
leftover crumbs from the days when a low-level debugger was hooked into
the exception entry code.

Now the exception entry sequence is essentially the same as for the
other exceptions, which still involves needlessly indirecting through
a function pointer which points to the same code on every platform.
Removing that indirection will be handled as a separate cleanup.

This work is based on an analysis by Juergen Weiss.

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Update all arm code that manipulates the PSR registers to use modern syntax.

It turns out the version of gas we're using interprets the old '_all' mask
as 'fc' instead of 'fsxc'. That is, "all" doe

Update all arm code that manipulates the PSR registers to use modern syntax.

It turns out the version of gas we're using interprets the old '_all' mask
as 'fc' instead of 'fsxc'. That is, "all" doesn't really mean "all".

This was the cause of the "wrong-endian register restore" bug that's
been causing problems with some cortex-a9 chips. The 'endian' bit in the
spsr register would never get changed (it falls into the 'x' mask group)
and the first return-from-exception would fail if the chip had powered on
with garbage in the spsr register that included the big-endian bit. It's
unknown why this affected only certain cortex-a9 chips.

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We no longer need to align the stack before calling swi_handler as it is
already aligned correctly in the PUSHFRAME macro.

Add UNWINDSVCFRAME to provide the unwind pseudo ops to allow us to unwind
past a trapframe.

Use this macro in exception_exit as it is the function the unwinder enters
as the functions that store the

Add UNWINDSVCFRAME to provide the unwind pseudo ops to allow us to unwind
past a trapframe.

Use this macro in exception_exit as it is the function the unwinder enters
as the functions that store the frame setting lr to point to it.

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Insert STOP_UNWINDING directives in the _start (kernel entry point) and
fork_trampoline (thread entry point) assembler routines, because it's
not possible to unwind beyond those points.

Also insert

Insert STOP_UNWINDING directives in the _start (kernel entry point) and
fork_trampoline (thread entry point) assembler routines, because it's
not possible to unwind beyond those points.

Also insert STOP_UNWINDING in the exception_exit routine, to prevent an
unwind-loop at that point. This is just a stopgap until we get around
to instrumenting all assembler functions with proper unwind metadata.

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Add an END macro to ARM. This is mostly used to tell gas where the bounds
of the functions are when creating the EABI unwind tables.

Tell the unwinder we can't unwind swi_entry. This fixes an infinite loop
when the kernel attempts to unwind through this function.

The .fnstart and .fnend in this function should be moved to macros

Tell the unwinder we can't unwind swi_entry. This fixes an infinite loop
when the kernel attempts to unwind through this function.

The .fnstart and .fnend in this function should be moved to macros but we
are currently missing an END macro on ARM.

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Ensure we align the stack to 8 bytes in system calls.

This is not strictly required with the current ABI but will be when we
switch to the ARM EABI. The aapcs requires the stack to be 4 byte aligned

Ensure we align the stack to 8 bytes in system calls.

This is not strictly required with the current ABI but will be when we
switch to the ARM EABI. The aapcs requires the stack to be 4 byte aligned
at all times and 8 byte aligned when calling a public subroutine where the
current ABI only requires sp to be a multiple of 4.

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Final whitespace trim.

Remove some long-dead code

Reviewed by: cognet

Start all license statements with /*-

Remove useless code.

Rename macroes, as we don't need to mess with alignment faults.
Call ast() if TDF_NEEDRESCHED is set too, not just TDF_ASTPENDING.

Remove filename+line number from panic messages.

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 videot

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.

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AST: rework

Make most AST handlers dynamically registered. This allows to have
subsystem-specific handler source located in the subsystem files,
instead of making subr_trap.c aware of it. For inst

AST: rework

Make most AST handlers dynamically registered. This allows to have
subsystem-specific handler source located in the subsystem files,
instead of making subr_trap.c aware of it. For instance, signal
delivery code on return to userspace is now moved to kern_sig.c.

Also, it allows to have some handlers designated as the cleanup (kclear)
type, which are called both at AST and on thread/process exit. For
instance, ast(), exit1(), and NFS server no longer need to be aware
about UFS softdep processing.

The dynamic registration also allows third-party modules to register AST
handlers if needed. There is one caveat with loadable modules: the
code does not make any effort to ensure that the module is not unloaded
before all threads processed through AST handler in it. In fact, this
is already present behavior for hwpmc.ko and ufs.ko. I do not think it
is worth the efforts and the runtime overhead to try to fix it.

Reviewed by: markj
Tested by: emaste (arm64), pho
Discussed with: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D35888

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Remove __XSCALE__ checks from the arm code

XScale support was removed over 2 years ago, remove the last __XSCALE__
checks from the arm MD code.

Sponsored by: Innovate UK

Remove the pre-ARMv6 and pre-INTRNG code.
ARM has required ARMV6+ and INTRNg for some time now, so remove
always false #ifdefs and unconditionally do always true #ifdefs.

Revert r336773: it removed too much.

r336773 removed all things xscale. However, some things xscale are
really armv5. Revert that entirely. A more modest removal will follow.

Noticed by: andrew@