Andrew Morton reported that AES-NI CTR optimization failed to compile
with gas 2.16.1, the error message is as follow:

arch/x86/crypto/aesni-intel_asm.S: Assembler messages:
arch/x86/crypto/aesni-intel_asm.S:752: Error: suffix or operands invalid for `movq'
arch/x86/crypto/aesni-intel_asm.S:753: Error: suffix or operands invalid for `movq'

To fix this, a gas macro is defined to assemble movq with 64bit
general purpose registers and XMM registers. The macro will generate
the raw .byte sequence for needed instructions.
Reported-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

To take advantage of the hardware pipeline implementation of AES-NI
instructions. CTR mode cryption is implemented in ASM to schedule
multiple AES-NI instructions one after another. This way, some latency
of AES-NI instruction can be eliminated.

Performance testing based on dm-crypt should 50% reduction of
ecryption/decryption time.
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Old binutils do not support AES-NI instructions, to make kernel can be
compiled by them, .byte code is used instead of AES-NI assembly
instructions. But the readability and flexibility of raw .byte code is
not good.

So corresponding assembly instruction like gas macro is used instead.
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Original implementation of aesni_cbc_dec do not save IV if input
length % 4 == 0. This will make decryption of next block failed.
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

Intel AES-NI is a new set of Single Instruction Multiple Data (SIMD)
instructions that are going to be introduced in the next generation of
Intel processor, as of 2009. These instructions enable fast and secure
data encryption and decryption, using the Advanced Encryption Standard
(AES), defined by FIPS Publication number 197.  The architecture
introduces six instructions that offer full hardware support for
AES. Four of them support high performance data encryption and
decryption, and the other two instructions support the AES key
expansion procedure.

The white paper can be downloaded from:

http://softwarecommunity.intel.com/isn/downloads/intelavx/AES-Instructions-Set_WP.pdf

AES may be used in soft_irq context, but MMX/SSE context can not be
touched safely in soft_irq context. So in_interrupt() is checked, if
in IRQ or soft_irq context, the general x86_64 implementation are used
instead.
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>