lwn.git/arch/s390/kernel/head64.S, branch docs-mw

s390: Rename head64.S to head.S

2025-11-25T14:28:07+00:00

All the code is 64 bit, therefore remove the superfluous suffix. Reviewed-by: Jens Remus Signed-off-by: Heiko Carstens

s390/time: Convert MACHINE_HAS_SCC to machine_has_scc()

2025-03-04T16:18:06+00:00

Use static branch(es) to implement and use machine_has_scc() instead of a runtime check via MACHINE_HAS_SCC. This comes with a cleanup of early time initialization: the initial tod_clock_base value is now passed via the bootdata mechanism, instead of using absolute lowcore as transport vehicle from the decompressor to the kernel. Also the early tod clock initialization is moved to the decompressor which allows to use a static branch with machine_has_scc() within the kernel. Reviewed-by: Vasily Gorbik Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/head64: Make startup code ready for lowcore relocation

2024-07-23T14:02:32+00:00

In preparation of having lowcore at different address than zero, add the base register to all lowcore accesses in startup_continue(). Reviewed-by: Heiko Carstens Signed-off-by: Sven Schnelle Signed-off-by: Vasily Gorbik

s390: consistently use .balign instead of .align

2023-06-28T11:57:09+00:00

The .align directive has inconsistent behavior across architectures. Use .balign instead everywhere. This is a no-op for s390, but with this there is no mix in using .align and .balign anymore. Future code is supposed to use only .balign. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev

s390/head64: use SYM* macros instead of ENTRY(), etc.

2023-04-19T15:24:17+00:00

Consistently use the SYM* family of macros instead of the deprecated ENTRY(), ENDPROC(), etc. family of macros. Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/stack: set lowcore kernel stack pointer early

2023-04-04T16:34:55+00:00

Make sure the lowcore kernel stack pointer reflects the kernel stack of the current task as early as possible, instead of having a NULL pointer there. Reviewed-by: Vasily Gorbik Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/stack: use STACK_INIT_OFFSET where possible

2023-04-04T16:34:55+00:00

Make STACK_INIT_OFFSET also available for assembler code, and use it everywhere instead of open-coding it at several places. Reviewed-by: Vasily Gorbik Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/kasan: move shadow mapping to decompressor

2023-03-20T10:02:51+00:00

Since regular paging structs are initialized in decompressor already move KASAN shadow mapping to decompressor as well. This helps to avoid allocating KASAN required memory in 1 large chunk, de-duplicate paging structs creation code and start the uncompressed kernel with KASAN instrumentation right away. This also allows to avoid all pitfalls accidentally calling KASAN instrumented code during KASAN initialization. Acked-by: Heiko Carstens Reviewed-by: Alexander Gordeev Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens

s390/early: fix sclp_early_sccb variable lifetime

2023-01-13T13:15:04+00:00

Commit ada1da31ce34 ("s390/sclp: sort out physical vs virtual pointers usage") fixed the notion of virtual address for sclp_early_sccb pointer. However, it did not take into account that kasan_early_init() can also output messages and sclp_early_sccb should be adjusted by the time kasan_early_init() is called. Currently it is not a problem, since virtual and physical addresses on s390 are the same. Nevertheless, should they ever differ, this would cause an invalid pointer access. Fixes: ada1da31ce34 ("s390/sclp: sort out physical vs virtual pointers usage") Reviewed-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Heiko Carstens

s390: remove invalid email address of Heiko Carstens

2022-02-06T22:31:29+00:00

Remove my old invalid email address which can be found in a couple of files. Instead of updating it, just remove my contact data completely from source files. We have git and other tools which allow to figure out who is responsible for what with recent contact data. Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik