save_and_disable_irqs does not need to use mov + msr (which was
introduced to work around a documentation bug which was propagated
into binutils.)  Use msr with an immediate constant, and if we're
building for ARMv6 or later, use the new CPSID instruction.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Nicolas Pitre

ARM processors that have pld instructions are not using those copy_user
implementation anymore.  Let's remove the useless PLD lines which were
half wrong anyway.
Signed-off-by: NNicolas Pitre <nico@cam.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The 'K' extension adds several new instructions to the ARMv6 ISA
which are primerily useful for SMP.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Nicolas Pitre

This patch provides a preemption safe implementation of copy_to_user
and copy_from_user based on the copy template also used for memcpy.
It is enabled unconditionally when CONFIG_PREEMPT=y.  Otherwise if the
configured architecture is not ARMv3 then it is enabled as well as it
gives better performances at least on StrongARM and XScale cores.  If
ARMv3 is not too affected or if it doesn't matter too much then
uaccess.S could be removed altogether.
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 provides a new implementation for optimized memory copy
functions on ARM.  It is made of two levels: a template that consists of
the core copy code and separate files that define macros to be used with
the core code depending on the type of copy needed. This allows for best
performances while sharing the same core for implementing memcpy(),
copy_from_user() and copy_to_user() for instance.

Two reasons for this work:

1) the current copy_to_user/copy_from_user implementation assumes no
   task switch will ever occur in the middle of each copied page making
   it completely unsafe with CONFIG_PREEMPT=y.

2) current copy implementations are measurably suboptimal and optimizing
   different implementations separately is a pain and more opportunities
   for bugs.

The reason for (1) is the fact that copy inside user pages are performed
with the ldm instruction which has no mean for testing user protections
and could possibly race with process preemption bypassing the COW mechanism
for example.  This is a longstanding issue that we said ought to be fixed
for about two years now.  The solution is to substitute those ldm insns
with a series of ldrt or strt insns to enforce user memory protection.
At least on StrongARM and XScale cores the ldm is not faster than the
equivalent ldr/str insns with a warm i-cache so there is no measurable
performance degradation with that change. The fact that the copy code is
a template makes it pretty easy to reuse the same core code as for memcpy
and benefit from the same performance optimizations.

Now (2) is best demonstrated with actual throughput measurements.
First, here is a summary of memcopy tests performed on a StrongARM core:

	PTR alignment	buffer size	kernel version	this version
	------------------------------------------------------------
	  aligned	     32		 59.73		107.43
	unaligned	     32		 61.31		 74.72
	  aligned	    100		132.47		136.15
	unaligned	    100	    	103.84		123.76
	  aligned	   4096		130.67		130.80
	unaligned	   4096	    	130.68		130.64
	  aligned	1048576		 68.03		68.18
	unaligned	1048576		 68.03		68.18

The buffer size is in bytes and the measured speed in MB/s.  The copy
was performed repeatedly with given buffer and throughput averaged over
3 seconds.

Here we can see that the current kernel version has a higher entry cost
that shows up with small buffers.  As buffer size grows both implementation
converge to the same throughput.

Now here's the exact same test performed on an XScale core (PXA255):

	PTR alignment	buffer size	kernel version	this version
	------------------------------------------------------------
	  aligned	     32		 46.99		 77.58
	unaligned	     32		 53.61		 59.59
	  aligned	    100		107.19		136.59
	unaligned	    100		 83.61		 97.58
	  aligned	   4096		129.13		129.98
	unaligned	   4096		128.36		128.53
	  aligned	1048576		 53.76		 59.41
	unaligned	1048576		 33.67		 56.96

Again we can see the entry setup cost being higher for the current kernel
before getting to the main copy loop.  Then throughput results converge
as long as the buffer remains in the cache. Then the 1MB case shows more
differences probably due to better pld placement and/or less instruction
interlocks in this proposed implementation.

Disclaimer: The PXA system was running with slower clocks than the
StrongARM system so trying to infer any conclusion by comparing those
separate sets of results side by side would be completely inappropriate.

So...  What this patch does is to replace both memcpy and memmove with
an implementation based on the provided copy code template.  The memmove
code is kept separate since it is used only if the memory areas involved
do overlap in which case the code is a transposition of the template but
with the copy occurring in the opposite direction (trying to fit that
mode into the template turned it into a mess not worth it for memmove
alone).  And obviously both memcpy and memmove were tested with all kinds
of pointer alignments and buffer sizes to exercise all code paths for
correctness.

The next patch will provide the now trivial replacement implementation
copy_to_user and copy_from_user.
Signed-off-by: NNicolas Pitre <nico@cam.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Nicolas Pitre

Required for future enhancement patches.
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 gets rid of the last C implementations of needed libgcc
functions for the kernel, replacing them with optimized assembly
versions.

Those functions are:

__ashldi3
__ashrdi3
__lshrdi3
__muldi3
__ucmpdi2

The first 3 were lifted from gcc, the other two were written from scratch.
Signed-off-by: NNicolas Pitre <nico@cam.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Nicolas Pitre

Here's an ARM assembly SHA1 implementation to replace the default C
version. It is approximately 50% faster than the generic C version. On
an XScale processor running at 400MHz:
	generic C version:	9.8 MB/s
	my version:		14.5 MB/s
This code is useful to quite a few callers in the tree:
crypto/sha1.c:		sha_transform(sctx->state, sctx->buffer, temp);
crypto/sha1.c:			sha_transform(sctx->state, &data[i], temp);
drivers/char/random.c:		sha_transform(buf, (__u8 *)r->pool+i, buf + 5);
drivers/char/random.c:	sha_transform(buf, (__u8 *)data, buf + 5);
net/ipv4/syncookies.c:	sha_transform(tmp + 16, (__u8 *)tmp, tmp + 16 + 5);
Signed-off-by: NNicolas Pitre <nico@cam.org>
Seems to work fine on big-endian as well.
Signed-off-by: NLennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Delete obsoleted stuff from arch Makefile and rename
constants.h to asm-offsets.h
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

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

We sometimes forgot to check whether the exclusive store succeeded.
Ensure that we always check.  Also ensure that we always use the
out of line versions, since the inline versions are not SMP safe.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

If we found that the bit was already in the desired state, we
would skip performing the operation, and write random data back.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Alexander Schulz

This patch brings a new default config file for the shark and
fixes a compilation issue with io addressing and a runtime
problem with the serial ports, where I corrected a wrong
regshift value.
These are all shark specific files so I hope it is ok to
put them in one patch.
Signed-off-by: NAlexander Schulz <alex@shark-linux.de>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

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

Patch from Nicolas Pitre

Those are big, slow and generally not recommended for kernel code.
They are even not present on i386.  So it should be concluded that
one could as well get away with do_div() alone.
Signed-off-by: NNicolas Pitre <nico@cam.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

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

Convert ugly GCC types to Linux types:

	UQImode -> u8
	SImode -> s32
	USImode -> u32
	DImode -> s64
	UDImode -> u64
	word_type -> int
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Patch from Nicolas Pitre

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

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

Convert ARM bitop assembly to a macro.  All bitops follow the same
format, so it's silly duplicating the code when only one or two
instructions are different.
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!