summaryrefslogtreecommitdiff
path: root/arch/s390/kernel/ftrace.c
diff options
context:
space:
mode:
authorVasily Gorbik <gor@linux.ibm.com>2022-02-24 22:43:31 +0100
committerVasily Gorbik <gor@linux.ibm.com>2022-03-10 15:58:17 +0100
commit4efd417f298bc23bc8b6ac5db5ff79af5ec92ac5 (patch)
tree41b6781eadef63b049d3c16fa5119f665c80f7a0 /arch/s390/kernel/ftrace.c
parent432b1cc78e985d3c783f1accb2507fbf5a87583d (diff)
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/kernel/ftrace.c')
-rw-r--r--arch/s390/kernel/ftrace.c17
1 files changed, 2 insertions, 15 deletions
diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c
index d8b96c5923c0..5e1f7bc00a25 100644
--- a/arch/s390/kernel/ftrace.c
+++ b/arch/s390/kernel/ftrace.c
@@ -60,15 +60,6 @@ asm(
#ifdef CONFIG_EXPOLINE
asm(
" .align 16\n"
- "ftrace_shared_hotpatch_trampoline_ex:\n"
- " lmg %r0,%r1,2(%r1)\n"
- " ex %r0," __stringify(__LC_BR_R1) "(%r0)\n"
- " j .\n"
- "ftrace_shared_hotpatch_trampoline_ex_end:\n"
-);
-
-asm(
- " .align 16\n"
"ftrace_shared_hotpatch_trampoline_exrl:\n"
" lmg %r0,%r1,2(%r1)\n"
" .insn ril,0xc60000000000,%r0,0f\n" /* exrl */
@@ -90,12 +81,8 @@ static const char *ftrace_shared_hotpatch_trampoline(const char **end)
tend = ftrace_shared_hotpatch_trampoline_br_end;
#ifdef CONFIG_EXPOLINE
if (!nospec_disable) {
- tstart = ftrace_shared_hotpatch_trampoline_ex;
- tend = ftrace_shared_hotpatch_trampoline_ex_end;
- if (test_facility(35)) { /* exrl */
- tstart = ftrace_shared_hotpatch_trampoline_exrl;
- tend = ftrace_shared_hotpatch_trampoline_exrl_end;
- }
+ tstart = ftrace_shared_hotpatch_trampoline_exrl;
+ tend = ftrace_shared_hotpatch_trampoline_exrl_end;
}
#endif /* CONFIG_EXPOLINE */
if (end)