[PATCH v3 0/9] s390/string: Convert various functions to C

[Heiko Carstens <hca@linux.ibm.com>]

v3:
 - Add additional patch which adds -ffreestanding compile option to
   string.o [Sashiko [3]]

v2:
Address various Shashiko findings [2]:

- Off by one comparison bug, which leads to slow path for memmove()
- Incorrect ifdef around __memset()
- Incorrect commit description for memmove() conversion
- Missing noinstr for tishift functions
- Missing header guard for tishift header file

v1:
While working on something else I stumbled again across the various mem*()
helper functions, which were implemented in assembler to avoid recursive
calls [1], when using the compiler's builtin functions.

Convert the functions back to C using inline assemblies, which makes them
hopefully a bit more readable and maintainable. Also improve the memmove()
implementation by using the mvcrl instruction for the backward copy case.

Thanks,
Heiko

[1] commit 535c611ddd3e ("s390/string: provide asm lib functions for memcpy and memcmp")
[2] https://sashiko.dev/#/patchset/20260607162937.2927356-1-hca%40linux.ibm.com
[3] https://sashiko.dev/#/patchset/20260608053754.571282-1-hca%40linux.ibm.com

Heiko Carstens (9):
  s390/purgatory: Enforce z10 minimum architecture level
  s390: Add .noinstr.text to boot and purgatory linker scripts
  s390/string: Add -ffreestanding compile option to string.o
  s390/string: Convert memmove() to C
  s390/string: Convert memset() to C
  s390/string: Convert memcpy() to C
  s390/string: Convert memset(16|32|64)() to C
  s390/memmove: Optimize backward copy case
  s390/tishift: Convert __ashlti3(), __ashrti3(), __lshrti3() to C

 arch/s390/boot/Makefile                |   7 +-
 arch/s390/boot/mem.S                   |   2 -
 arch/s390/boot/string.c                |   6 +-
 arch/s390/boot/vmlinux.lds.S           |   1 +
 arch/s390/include/asm/asm-prototypes.h |   4 -
 arch/s390/lib/Makefile                 |   6 +-
 arch/s390/lib/mem.S                    | 192 ----------------------
 arch/s390/lib/string.c                 | 210 +++++++++++++++++++++++++
 arch/s390/lib/tishift.S                |  63 --------
 arch/s390/lib/tishift.c                |  64 ++++++++
 arch/s390/lib/tishift.h                |   9 ++
 arch/s390/purgatory/Makefile           |   9 +-
 arch/s390/purgatory/purgatory.lds.S    |   1 +
 13 files changed, 301 insertions(+), 273 deletions(-)
 delete mode 100644 arch/s390/boot/mem.S
 delete mode 100644 arch/s390/lib/mem.S
 delete mode 100644 arch/s390/lib/tishift.S
 create mode 100644 arch/s390/lib/tishift.c
 create mode 100644 arch/s390/lib/tishift.h

-- 
2.53.0