diff options
| author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2023-10-04 17:53:12 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-10-18 14:34:17 -0700 |
| commit | 2a667285b53c58d72f8bdb736c040f0f36bff58a (patch) | |
| tree | 910a25dfd4786d6a5a770332bee8d95a3e22068f | |
| parent | 51a752c28bcf901618bbc25a43f84ef539f9e682 (diff) | |
riscv: implement xor_unlock_is_negative_byte
Inspired by the riscv clear_bit_unlock(), this will surely be
more efficient than the generic one defined in filemap.c.
Link: https://lkml.kernel.org/r/20231004165317.1061855-13-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | arch/riscv/include/asm/bitops.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/bitops.h b/arch/riscv/include/asm/bitops.h index 3540b690944b..15e3044298a2 100644 --- a/arch/riscv/include/asm/bitops.h +++ b/arch/riscv/include/asm/bitops.h @@ -191,6 +191,19 @@ static inline void __clear_bit_unlock( clear_bit_unlock(nr, addr); } +static inline bool xor_unlock_is_negative_byte(unsigned long mask, + volatile unsigned long *addr) +{ + unsigned long res; + __asm__ __volatile__ ( + __AMO(xor) ".rl %0, %2, %1" + : "=r" (res), "+A" (*addr) + : "r" (__NOP(mask)) + : "memory"); + return (res & BIT(7)) != 0; +} +#define xor_unlock_is_negative_byte xor_unlock_is_negative_byte + #undef __test_and_op_bit #undef __op_bit #undef __NOP |