Commit Graph

8 Commits

Author SHA1 Message Date
Heiko Carstens
b9be1bee2f s390/asm-offsets: Remove ASM_OFFSETS_C
Remove ASM_OFFSETS_C which is used as guard in thread_info.h to decide if
asm-offsets can be included or not.

There is no reason to include asm-offsets.h in thread_info.h anymore.
Remove the define and the not needed include. Explicitly include
asm-offsets.h in all header files which require it, and where it used
to be included implicitly via thread_info.h.

This reduces header dependencies.

Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2025-03-31 12:20:39 +02:00
Heiko Carstens
0dafe9968a s390: Use inline qualifier for all EX_TABLE and ALTERNATIVE inline assemblies
Use asm_inline for all inline assemblies which make use of the EX_TABLE or
ALTERNATIVE macros.

These macros expand to many lines and the compiler assumes the number of
lines within an inline assembly is the same as the number of instructions
within an inline assembly. This has an effect on inlining and loop
unrolling decisions.

In order to avoid incorrect assumptions use asm_inline, which tells the
compiler that an inline assembly has the smallest possible size.

In order to avoid confusion when asm_inline should be used or not, since a
couple of inline assemblies are quite large: the rule is to always use
asm_inline whenever the EX_TABLE or ALTERNATIVE macro is used. In specific
cases there may be reasons to not follow this guideline, but that should
be documented with the corresponding code.

Using the inline qualifier everywhere has only a small effect on the kernel
image size:

add/remove: 0/10 grow/shrink: 19/8 up/down: 1492/-1858 (-366)

The only location where this seems to matter is load_unaligned_zeropad()
from word-at-a-time.h where the compiler inlines more functions within the
dcache code, which is indeed code where performance matters.

Suggested-by: Juergen Christ <jchrist@linux.ibm.com>
Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2025-03-18 17:13:51 +01:00
Heiko Carstens
46a923fd86 s390/pfault: use consistent comment style
Use consistent comment style within the whole pfault C code.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-29 14:57:18 +02:00
Heiko Carstens
4c89eb8744 s390/pfault: cleanup inline assemblies
Cleanup the pfault inline assemblies:
- Use symbolic names for operands
- Add extra linebreaks, and whitespace to improve readability

In addition, change __pfault_init() to return -EOPNOTSUPP in case of
an exception, and don't return a made up valid diag 258 return value
(aka "8").
This allows to simplify the inline assembly, and makes debugging
easier, in case something is broken.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-29 14:57:18 +02:00
Heiko Carstens
28254f36e2 s390/pfault: use early_param() instead if __setup()
early_param() is the standard way of defining early kernel command
line parameters. Use that instead of the old __setup() variant.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-29 14:57:18 +02:00
Heiko Carstens
c5b6eef58f s390/pfault: remove not needed packed and aligned attributes
struct pfault_refbk is naturally packed and aligned; remove not needed
packed and aligned attributes.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-29 14:57:18 +02:00
Heiko Carstens
b60624bb0a s390/pfault: use UL instead of ULL
Remove another leftover of the 31 bit area: replace the not needed
"unsigned long long" suffix with "unsigned long", and stay consistent
with the rest of the code.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-29 14:57:18 +02:00
Heiko Carstens
c28c07fe23 s390/mm: move pfault code to own C file
The pfault code has nothing to do with regular fault handling.

Therefore move it to an own C file. Also add an own pfault header
file. This way changes to setup.h don't cause a recompile of the
pfault code and vice versa.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2023-07-29 14:57:18 +02:00