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!