Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Patch from Lennert Buytenhek

Add the necessary kernel bits for crunch task switching.
Signed-off-by: NLennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Some machine classes need to allow VFP support to be built into the
kernel, but still allow the kernel to run even though VFP isn't
present.  Unfortunately, the kernel hard-codes VFP instructions
into the thread switch, which prevents this being run-time selectable.

Solve this by introducing a notifier which things such as VFP can
hook into to be informed of events which affect the VFP subsystem
(eg, creation and destruction of threads, switches between threads.)
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Paul Brook

The example code in the source documentation for __kernel_dmb
clobbers r0 but doesn't list it the asm clobber list.
Signed-off-by: NPaul Brook <paul@codesourcery.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Allow the individual coprocessor handlers to decide when to enable
interrupts, rather than unconditionally enabling them.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

CONFIG_CPU_MPCORE has never been a configuration symbol - it should
be CONFIG_CPU_32v6K.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

 negative

Patch from Nicolas Pitre

The pre ARMv5 implementation can be aborted if an exception occurs in
the middle of it.  Because of that, the ARMv6 implementation doesn't
re-attempt the operation on a failed strex either.  Let's make this
transient nature of such a false positive more explicit in the
definition.
Signed-off-by: NNicolas Pitre <nico@cam.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Nicolas Pitre

The cmpxchg emulation on pre-ARMv5 relies on user code executed from a
kernel address.  If the operation cannot complete atomically, it is
aborted from the usr_entry macro by clearing the Z flag.  This clearing
of the Z flag is done whenever the user pc is above TASK_SIZE.

However this "pc >= TASK_SIZE" test cannot work in the non MMU case.
Worse: the current code will corrupt the Z flag on every entry to the
kernel.

Let's disable it in the non MMU case for now.  Using NPTL on non MMU
targets needs to be worked out anyway.
Signed-off-by: NNicolas Pitre <nico@cam.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Nicolas Pitre

This is kernel provided user space code.

Since a syscall is used, it has to be updated to work with EABI.
Signed-off-by: NNicolas Pitre <nico@cam.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Nicolas Pitre

The ARM EABI says that the stack pointer has to be 64-bit aligned for
reasons already mentioned in patch #3101 when calling C functions.

We therefore must verify and adjust sp accordingly when taking an
exception from kernel mode since sp might not necessarily be 64-bit
aligned if the exception occurs in the middle of a kernel function.

If the exception occurs while in user mode then no sp fixup is needed as
long as sizeof(struct pt_regs) as well as any additional syscall data
stack space remain multiples of 8.
Signed-off-by: NNicolas Pitre <nico@cam.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This patch adds register switch support in nommu mode.
Signed-off-by: NHyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/kernel/entry-armv.S has contained a comment suggesting
that asm/hardware.h and asm/arch/irqs.h should be moved into the
asm/arch/entry-macro.S include.  So move the includes to these
two files as required.

Add missing includes (asm/hardware.h, asm/io.h) to asm/arch/system.h
includes which use those facilities, and remove asm/io.h from
kernel/process.c.

Remove other unnecessary includes from arch/arm/kernel, arch/arm/mm
and arch/arm/mach-footbridge.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Nicolas Pitre

Strictly speaking, the NPTL kernel helpers are required for pre ARMv6
only.  They are available on ARMv6+ as well for obvious compatibility
reasons.  However there are cases where extra memory barriers are needed
when using an SMP ARMv6 machine but not on pre-ARMv6.

This patch adds a memory barrier kernel helper that glibc can use as
needed for pre-ARMv6 binaries to be forward compatible with an SMP
kernel on ARMv6, as well as the necessary dmb instructions to the
cmpxchg helper.
Signed-off-by: NNicolas Pitre <nico@cam.org>
Acked-by: NDaniel Jacobowitz <dan@codesourcery.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Add infrastructure for supporting per-cpu local timers to update
the profiling information and update system time accounting.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Nicolas Pitre

Since we know the value of cpsr on entry, we can replace the bic+orr with
a single eor.  Also remove a possible result delay (at least on XScale).
Signed-off-by: NNicolas Pitre <nico@cam.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Nicolas Pitre

This patch allows for assorted type of cleanups by letting assembly code
use the same set of defines for constant values and avoid duplicated
definitions that might not always be in sync, or that might simply be
confusing due to the different names for the same thing.
Signed-off-by: NNicolas Pitre <nico@cam.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

We accidentally corrupted the TLS value when clearing out the ARMv6
exclusive monitor.  Avoid doing so.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Ensure that the exclusive monitor is cleared on context switch with
ARMv6 CPUs.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Nicolas Pitre

Not that there might be many of them on the planet, but at least RMK
apparently has one.

Signed-off-by: Nicolas Pitre
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The current vector entry system does not allow for SMP.  In
order to work around this, we need to eliminate our reliance
on the fixed save areas, which breaks the way we enable
alignment traps.  This patch changes the way we handle the
save areas such that we can have one per CPU.
Signed-off-by: NRussell King <rmk@arm.linux.org.uk>

The current vector entry system does not allow for SMP.  In
order to work around this, we need to eliminate our reliance
on the fixed save areas, which breaks the way we enable
alignment traps.  This patch makes the alignment trap enable
code independent of the way we handle the save areas.
Signed-off-by: NRussell King <rmk@arm.linux.org.uk>

Add support for inter-processor interrupts to the main IRQ
handling code.
Signed-off-by: NRussell King <rmk@arm.linux.org.uk>

By changing r9 -> r8 and r8 to 'tsk' (r9) we are able to remove
one instruction from the preempt path.
Signed-off-by: NRussell King <rmk@arm.linux.org.uk>

Signed-off-by: NRussell King <rmk@arm.linux.org.uk>

Patch from Nicolas Pitre

Signed-off-by: Nicolas Pitre
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Nicolas Pitre

This better express things, and should cover RMK's weird SMP toys.

Signed-off-by: Nicolas Pitre
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Nicolas Pitre

This patch entirely reworks the kernel assistance for NPTL on ARM.
In particular this provides an efficient way to retrieve the TLS
value and perform atomic operations without any instruction emulation
nor special system call.  This even allows for pre ARMv6 binaries to
be forward compatible with SMP systems without any penalty.
The problematic and performance critical operations are performed
through segment of kernel provided user code reachable from user space
at a fixed address in kernel memory.  Those fixed entry points are
within the vector page so we basically get it for free as no extra
memory page is required and nothing else may be mapped at that
location anyway.
This is different from (but doesn't preclude) a full blown VDSO
implementation, however a VDSO would prevent some assembly tricks with
constants that allows for efficient branching to those code segments.
And since those code segments only use a few cycles before returning to
user code, the overhead of a VDSO far call would add a significant
overhead to such minimalistic operations.
The ARM_NR_set_tls syscall also changed number.  This is done for two
reasons:
1) this patch changes the way the TLS value was previously meant to be
   retrieved, therefore we ensure whatever library using the old way
   gets fixed (they only exist in private tree at the moment since the
   NPTL work is still progressing).
2) the previous number was allocated in a range causing an undefined
   instruction trap on kernels not supporting that syscall and it was
   determined that allocating it in a range returning -ENOSYS would be
   much nicer for libraries trying to determine if the feature is
   present or not.

Signed-off-by: Nicolas Pitre
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Move common includes to entry-header, and file specific includes
to the relevant file.
Signed-off-by: NRussell King <rmk@arm.linux.org.uk>

SVC_MODE reflects the MODE_SVC definition in asm/ptrace.h.  Use
the asm/ptrace.h definition instead, and remove SVC_MODE.
Signed-off-by: NRussell King <rmk@arm.linux.org.uk>

Since we do not require a register for these operations, we can
remove this unnecessary argument.
Signed-off-by: NRussell King <rmk@arm.linux.org.uk>

Convert the trivial vector entry initialisation code to C code.
Signed-off-by: NRussell King <rmk@arm.linux.org.uk>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!