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| author |   Vasily Gorbik <gor@linux.ibm.com> | 2022-02-24 22:43:31 +0100 |
|---|---|---|
| committer | Vasily Gorbik <gor@linux.ibm.com> | 2022-03-10 15:58:17 +0100 |
| commit | 4efd417f298bc23bc8b6ac5db5ff79af5ec92ac5 (patch) | |
| tree | 41b6781eadef63b049d3c16fa5119f665c80f7a0 /arch/s390/mm | |
| parent | s390/uaccess: Add copy_from/to_user_key functions (diff) | |
| download | linux-dev-4efd417f298bc23bc8b6ac5db5ff79af5ec92ac5.tar.xz linux-dev-4efd417f298bc23bc8b6ac5db5ff79af5ec92ac5.zip | |
s390: raise minimum supported machine generation to z10
Machine generations up to z9 (released in May 2006) have been officially
out of service for several years now (z9 end of service - January 31, 2019).
No distributions build kernels supporting those old machine generations
anymore, except Debian, which seems to pick the oldest supported
generation. The team supporting Debian on s390 has been notified about
the change.
Raising minimum supported machine generation to z10 helps to reduce
maintenance cost and effectively remove code, which is not getting
enough testing coverage due to lack of older hardware and distributions
support. Besides that this unblocks some optimization opportunities and
allows to use wider instruction set in asm files for future features
implementation. Due to this change spectre mitigation and usercopy
implementations could be drastically simplified and many newer instructions
could be converted from ".insn" encoding to instruction names.
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch/s390/mm')
| -rw-r--r-- | arch/s390/mm/vmem.c | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c index 72c525ce7221..c2583f921ca8 100644 --- a/arch/s390/mm/vmem.c +++ b/arch/s390/mm/vmem.c @@ -584,13 +584,9 @@ void __init vmem_map_init(void) __set_memory(__stext_amode31, (__etext_amode31 - __stext_amode31) >> PAGE_SHIFT, SET_MEMORY_RO | SET_MEMORY_X); - if (nospec_uses_trampoline() || !static_key_enabled(&cpu_has_bear)) { - /* - * Lowcore must be executable for LPSWE - * and expoline trampoline branch instructions. - */ + /* lowcore must be executable for LPSWE */ + if (!static_key_enabled(&cpu_has_bear)) set_memory_x(0, 1); - } pr_info("Write protected kernel read-only data: %luk\n", (unsigned long)(__end_rodata - _stext) >> 10); |