Switch to Google ToolChain GCC 4.8
ARM: use generic strnlen_user and strncpy_from_user functions

This patch implements the word-at-a-time interface for ARM using the
same algorithm as x86. We use the fls macro from ARMv5 onwards, where
we have a clz instruction available which saves us a mov instruction
when targetting Thumb-2. For older CPUs, we use the magic 0x0ff0001
constant. Big-endian configurations make use of the implementation from
asm-generic.

With this implemented, we can replace our byte-at-a-time strnlen_user
and strncpy_from_user functions with the optimised generic versions.

Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
modified for Mako from LKML reference

Signed-off-by: Paul Reioux <reioux@gmail.com>
ARM: dcache: select DCACHE_WORD_ACCESS for little-endian ARMv6+ CPUs

DCACHE_WORD_ACCESS uses the word-at-a-time API for optimised string
comparisons in the vfs layer.

This patch implements support for load_unaligned_zeropad for ARM CPUs
with native support for unaligned memory accesses (v6+) when running
little-endian.

Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
ARM: 7593/1: nommu: do not enable DCACHE_WORD_ACCESS when !CONFIG_MMU

Commit b9a50f74905a ("ARM: 7450/1: dcache: select DCACHE_WORD_ACCESS for
little-endian ARMv6+ CPUs") added support for word-at-time path
comparisons, relying on the ability to perform unaligned loads with
negligible performance impact in hardware.

For nommu configurations without MPU support, this is unpredictable and
so we should fall back to the byte-by-byte routines.

Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Jonathan Austin <jonathan.austin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
modified for Mako from kernel.org

Signed-off-by: faux123 <reioux@gmail.com>
arch/arm/kernel/armksyms: fix merge derp

Signed-off-by: Paul Reioux <reioux@gmail.com>

Conflicts:

	arch/arm/kernel/armksyms.c
ARM: 7927/1: dcache: select DCACHE_WORD_ACCESS for big-endian CPUs

With commit 11ec50caedb5 ("word-at-a-time: provide generic big-endian
zero_bytemask implementation"), the asm-generic word-at-a-time code now
provides a zero_bytemask implementation, allowing us to make use of
DCACHE_WORD_ACCESS on big-endian CPUs, providing our
load_unaligned_zeropad function is endianness-clean.

This patch reworks the load_unaligned_zeropad fixup code to work for
both big- and little-endian CPUs, then removes the !CPU_BIG_ENDIAN check
when selecting DCACHE_WORD_ACCESS.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
lib: add generic strnlen_user() function

This adds a new generic optimized strnlen_user() function that uses the
<asm/word-at-a-time.h> infrastructure to portably do efficient string
handling.

In many ways, strnlen is much simpler than strncpy, and in particular we
can always pre-align the words we load from memory.  That means that all
the worries about alignment etc are a non-issue, so this one can easily
be used on any architecture.  You obviously do have to do the
appropriate word-at-a-time.h macros.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Paul Reioux <reioux@gmail.com>
lib: Fix generic strnlen_user for 32-bit big-endian machines

The aligned_byte_mask() definition is wrong for 32-bit big-endian
machines: the "7-(n)" part of the definition assumes a long is 8
bytes.  This fixes it by using BITS_PER_LONG - 8 instead of 8*7.
Tested on 32-bit and 64-bit PowerPC.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>