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s390/bitops: Use correct constraint for arch_test_bit() inline assembly

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Use the "Q" instead of "R" constraint to correctly reflect the instruction
format of the tm instruction: the first operand is a memory reference
without index register and short displacement. The "R" constraint indicates
a memory reference with index register instead.

This may lead to compile errors like:

  arch/s390/include/asm/bitops.h: Assembler messages:
  arch/s390/include/asm/bitops.h:60: Error: operand 1: syntax error; missing ')' after base register
  arch/s390/include/asm/bitops.h:60: Error: operand 2: syntax error; ')' not allowed here
  arch/s390/include/asm/bitops.h:60: Error: junk at end of line: `,4'

Reported-by: Nathan Chancellor <nathan@kernel.org>
Closes: https://lore.kernel.org/r/20250122-s390-fix-std-for-gcc-15-v1-1-8b00cadee083@kernel.org
Fixes: b2bc1b1a77 ("s390/bitops: Provide optimized arch_test_bit()")
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
This commit is contained in:
Heiko Carstens 2025-01-23 09:14:15 +01:00 committed by Alexander Gordeev
parent dc287e4c91
commit 0a89123dee
1 changed files with 1 additions and 1 deletions
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2
arch/s390/include/asm/bitops.h
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@ -60,7 +60,7 @@ static __always_inline bool arch_test_bit(unsigned long nr, const volatile unsig
asm volatile(
" tm %[addr],%[mask]\n"
: "=@cc" (cc)
: [addr] "R" (*addr), [mask] "I" (mask)
: [addr] "Q" (*addr), [mask] "I" (mask)
);
return cc == 3;
}