s390/fpu: move, rename, and merge header files

Move, rename, and merge the fpu and vx header files. This way fpu header
files have a consistent naming scheme (fpu*.h).

Also get rid of the fpu subdirectory and move header files to asm
directory, so that all fpu and vx header files can be found at the same
location.

Merge internal.h header file into other header files, since the internal
helpers are used at many locations. so those helper functions are really
not internal.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/crypto,chacha: use SYM* macros instead of ENTRY(), etc.

Consistently use the SYM* family of macros instead of the
deprecated ENTRY(), ENDPROC(), etc. family of macros.

Acked-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390: convert ".insn" encoding to instruction names

With z10 as minimum supported machine generation many ".insn" encodings
could be now converted to instruction names. There are couple of exceptions
- stfle is used from the als code built for z900 and cannot be converted
- few ".insn" directives encode unsupported instruction formats

The generated code is identical before/after this change.

Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/crypto: fix compile error for ChaCha20 module

The clgfi instruction used within the ChaCha20 assembly is only
available for z9-109 and newer machines, and therefore this will
generate a compile error if compiled e.g. with MARCH_Z900.

Given that the assembler code will only be executed on machines with
vector instructions, which became much later available than z9-109,
use insn notation to generate the clgfi instruction, and avoid compile
errors due to unknown instructions.

Fixes: b087dfab4d39 ("s390/crypto: add SIMD implementation for ChaCha20")
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/crypto: add SIMD implementation for ChaCha20

Add an implementation of the ChaCha20 stream cipher (see e.g. RFC 7539)
that makes use of z13's vector instruction set extension.

The original implementation is by Andy Polyakov which is
adapted for kernel use.

Four to six blocks are processed in parallel resulting in a performance
gain for inputs >= 256 bytes.

chacha20-generic

1 operation in 622 cycles (256 bytes)
1 operation in 2346 cycles (1024 bytes)

chacha20-s390

1 operation in 218 cycles (256 bytes)
1 operation in 647 cycles (1024 bytes)

Cc: Andy Polyakov <appro@openssl.org>
Reviewed-by: Harald Freudenberger <freude@de.ibm.com>
Signed-off-by: Patrick Steuer <patrick.steuer@de.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>