[PATCH v3 0/4] s390: Enable Rust support and add required arch glue

[Jan Polensky <japo@linux.ibm.com>]

Rust support on s390 requires a small set of architecture-specific pieces
before the generic Rust kernel infrastructure can be used.

The series wires up s390 as a Rust-capable 64-bit architecture, adds the
missing assembly interfaces needed by Rust for WARN/BUG reporting and for
static branches, and adjusts bindgen parameters to avoid repr layout
conflicts caused by packed and aligned s390 structures.

s390 currently requires a rustc due to -Zpacked-stack, and the
minimum tool version gating is adjusted accordingly.

Link: https://github.com/Rust-for-Linux/linux/issues/2

Tested against: rustc 1.96.0-beta.7 (6be5f81e1 2026-05-17)

Changes since v2:
- mflags: cleanup (thanks Gary)
Changes since v1:
- strip the -nightly suffix in min-tool-version.sh (thanks miguel and alice)
- ARCH_JUMP_TABLE_ENTRY() moved up to align comments properly (thanks Gary)
- removed MONCODE_BUG to prevent 0U in non-C context in assembler (noted by Sashiko - AI)
- prevent environment pollution by explicit initialization mflag := (noted by Sashiko - AI)


Jan Polensky (4):
  s390/bug: Provide ARCH_WARN_ASM for Rust WARN/BUG support
  s390/jump_label: Implement ARCH_STATIC_BRANCH_JUMP_ASM and
    ARCH_STATIC_BRANCH_ASM macros
  rust/bindgen_parameters: Mark s390 types as opaque to prevent repr
    conflicts
  s390: Enable Rust support

 Documentation/rust/arch-support.rst |  1 +
 arch/s390/Kconfig                   |  1 +
 arch/s390/Makefile                  | 28 ++++++++++++++----------
 arch/s390/include/asm/bug.h         | 12 +++++++++++
 arch/s390/include/asm/jump_label.h  | 33 +++++++++++++++++------------
 rust/Makefile                       |  1 +
 rust/bindgen_parameters             |  7 ++++++
 scripts/generate_rust_target.rs     |  2 ++
 scripts/min-tool-version.sh         |  6 +++++-
 9 files changed, 65 insertions(+), 26 deletions(-)


base-commit: 758c807bb943138f887d42d986b645e12446ba9c
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2.51.0