Provide various vector instruction inline assemblies for crc32
calculations.
This is just preparation to keep the conversion of the existing crc32
implementations from assembly to C small.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Provide several one instruction fpu inline assemebles and use them to
implement the bogomips calculation in C like style. This is more for
illustration purposes on how kernel fpu code can be written in C.
This has the advantage that the author only has to take care of the
floating point instructions, but doesn't need to take care of general
purpose register allocation (if needed), and the semantics of all other
instructions not related to fpu.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Move the s390 specific raid6 inline assemblies, make them generic, and
reuse them to implement the raid6 gen/xor implementation.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
With csum_partial(), which reads all bytes into registers it is easy to
also implement csum_partial_copy_nocheck() which copies the buffer while
calculating its checksum.
For a 512 byte buffer this reduces the runtime by 19%. Compared to the old
generic variant (memcpy() + cksm instruction) runtime is reduced by 42%).
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Provide a faster variant of csum_partial() which uses vector registers
instead of the cksm instruction.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Let fpu_vlm() and fpu_vstm() macros return the number of registers saved /
loaded. This is helpful to read easy to read code in case there are several
subsequent fpu_vlm() or fpu_vstm() calls:
__vector128 *vxrs = ....
vxrs += fpu_vstm(0, 15, vxrs);
vxrs += fpu_vstm(16, 31, vxrs);
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Instead of open-coding vlm and vstm inline assemblies at several locations,
provide an fpu_* function for each instruction, and use them in the new
save_vx_regs() and load_vx_regs() helper functions.
Note that "O" and "R" inline assembly operand modifiers are used in order
to pass the displacement and base register of the memory operands to the
existing VLM and VSTM macros. The two operand modifiers are not available
for clang. Therefore provide two variants of each inline assembly.
The clang variant always uses and clobbers general purpose register 1, like
in the previous inline assemblies, so it can be used as base register with
a zero displacement. This generates slightly less efficient code, but can
be removed as soon as clang has support for the used operand modifiers.
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Instead of open-coding lfpc, sfpc, and stfpc inline assemblies at
several locations, provide an fpu_* function for each instruction and
use the function instead.
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Deduplicate the 64 ld and std inline assemblies. Provide an fpu inline
assembly for both instructions, and use them in the new save_fp_regs()
and load_fp_regs() helper functions.
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The only user of sfpc_safe() needs to read the new fpc register value
from memory before it is set with sfpc.
Avoid this indirection and use lfpc, which reads the new value from
memory. Also add the "fpu_" prefix to have a common name space for fpu
related inline assemblies, and provide memory access instrumentation.
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Add documentation which describes what the fpu helper functions are
good for, and why they should be used.
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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>
