diff options
| author | Vivian Wang <wangruikang@iscas.ac.cn> | 2025-11-17 21:19:22 -0700 |
|---|---|---|
| committer | Paul Walmsley <pjw@kernel.org> | 2025-11-19 09:19:28 -0700 |
| commit | 6b85e9ac4a25c5e69f8121e95eea14da6e3df2fa (patch) | |
| tree | 99f058ee03bcb663f1d5c267db39c51e3e457412 | |
| parent | 8261a9d167e8b3007c0e830a1f7ab8c8b8c24b79 (diff) | |
riscv: bitops: Use riscv_has_extension_likely
Use riscv_has_extension_likely() to check for RISCV_ISA_EXT_ZBB,
replacing the use of asm goto with ALTERNATIVE.
The "likely" variant is used to match the behavior of the original
implementation using ALTERNATIVE("j %l[legacy]", "nop", ...).
Signed-off-by: Vivian Wang <wangruikang@iscas.ac.cn>
Link: https://patch.msgid.link/20251020-riscv-altn-helper-wip-v4-4-ef941c87669a@iscas.ac.cn
Signed-off-by: Paul Walmsley <pjw@kernel.org>
| -rw-r--r-- | arch/riscv/include/asm/bitops.h | 32 |
1 files changed, 8 insertions, 24 deletions
diff --git a/arch/riscv/include/asm/bitops.h b/arch/riscv/include/asm/bitops.h index 77880677b06e..238092125c11 100644 --- a/arch/riscv/include/asm/bitops.h +++ b/arch/riscv/include/asm/bitops.h @@ -47,9 +47,8 @@ static __always_inline __attribute_const__ unsigned long variable__ffs(unsigned long word) { - asm goto(ALTERNATIVE("j %l[legacy]", "nop", 0, - RISCV_ISA_EXT_ZBB, 1) - : : : : legacy); + if (!riscv_has_extension_likely(RISCV_ISA_EXT_ZBB)) + return generic___ffs(word); asm volatile (".option push\n" ".option arch,+zbb\n" @@ -58,9 +57,6 @@ static __always_inline __attribute_const__ unsigned long variable__ffs(unsigned : "=r" (word) : "r" (word) :); return word; - -legacy: - return generic___ffs(word); } /** @@ -76,9 +72,8 @@ legacy: static __always_inline __attribute_const__ unsigned long variable__fls(unsigned long word) { - asm goto(ALTERNATIVE("j %l[legacy]", "nop", 0, - RISCV_ISA_EXT_ZBB, 1) - : : : : legacy); + if (!riscv_has_extension_likely(RISCV_ISA_EXT_ZBB)) + return generic___fls(word); asm volatile (".option push\n" ".option arch,+zbb\n" @@ -87,9 +82,6 @@ static __always_inline __attribute_const__ unsigned long variable__fls(unsigned : "=r" (word) : "r" (word) :); return BITS_PER_LONG - 1 - word; - -legacy: - return generic___fls(word); } /** @@ -105,9 +97,8 @@ legacy: static __always_inline __attribute_const__ int variable_ffs(int x) { - asm goto(ALTERNATIVE("j %l[legacy]", "nop", 0, - RISCV_ISA_EXT_ZBB, 1) - : : : : legacy); + if (!riscv_has_extension_likely(RISCV_ISA_EXT_ZBB)) + return generic_ffs(x); if (!x) return 0; @@ -119,9 +110,6 @@ static __always_inline __attribute_const__ int variable_ffs(int x) : "=r" (x) : "r" (x) :); return x + 1; - -legacy: - return generic_ffs(x); } /** @@ -137,9 +125,8 @@ legacy: static __always_inline int variable_fls(unsigned int x) { - asm goto(ALTERNATIVE("j %l[legacy]", "nop", 0, - RISCV_ISA_EXT_ZBB, 1) - : : : : legacy); + if (!riscv_has_extension_likely(RISCV_ISA_EXT_ZBB)) + return generic_fls(x); if (!x) return 0; @@ -151,9 +138,6 @@ static __always_inline int variable_fls(unsigned int x) : "=r" (x) : "r" (x) :); return 32 - x; - -legacy: - return generic_fls(x); } /** |