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s390/entry: workaround llvm's IAS limitations

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llvm's integrated assembler cannot handle immediate values which are
calculated with two local labels:

<instantiation>:3:13: error: invalid operand for instruction
 clgfi %r14,.Lsie_done - .Lsie_gmap

Workaround this by adding clang specific code which reads the specific
value from memory. Since this code is within the hot paths of the kernel
and adds an additional memory reference, keep the original code, and add
ifdef'ed code.

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/r/20220511120532.2228616-5-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
This commit is contained in:
Heiko Carstens 2022-05-11 14:05:27 +02:00
parent e6ed91fd07
commit 4c25f0ff63
1 changed files with 12 additions and 2 deletions
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14
arch/s390/kernel/entry.S
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@ -172,9 +172,19 @@ _LPP_OFFSET = __LC_LPP
lgr %r14,\reg
larl %r13,\start
slgr %r14,%r13
lghi %r13,\end - \start
clgr %r14,%r13
#ifdef CONFIG_AS_IS_LLVM
clgfrl %r14,.Lrange_size\@
#else
clgfi %r14,\end - \start
#endif
jhe \outside_label
#ifdef CONFIG_AS_IS_LLVM
.section .rodata, "a"
.align 4
.Lrange_size\@:
.long \end - \start
.previous
#endif
.endm
.macro SIEEXIT