diff options
author | Xiao Wang <xiao.w.wang@intel.com> | 2023-11-12 12:44:21 +0300 |
---|---|---|
committer | Palmer Dabbelt <palmer@rivosinc.com> | 2024-01-25 04:25:36 +0300 |
commit | cb4ede926134a65bc3bf90ed58dace8451d7e759 (patch) | |
tree | 1ae5694003cd1566bd5a460e80a16ab1f63c2688 /arch | |
parent | 05d450aabd7386246c5aafc341fe9febe5855967 (diff) | |
download | linux-cb4ede926134a65bc3bf90ed58dace8451d7e759.tar.xz |
riscv: Avoid code duplication with generic bitops implementation
There's code duplication between the fallback implementation for bitops
__ffs/__fls/ffs/fls API and the generic C implementation in
include/asm-generic/bitops/. To avoid this duplication, this patch renames
the generic C implementation by adding a "generic_" prefix to them, then we
can use these generic APIs as fallback.
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Xiao Wang <xiao.w.wang@intel.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20231112094421.4014931-1-xiao.w.wang@intel.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/riscv/include/asm/bitops.h | 138 |
1 files changed, 24 insertions, 114 deletions
diff --git a/arch/riscv/include/asm/bitops.h b/arch/riscv/include/asm/bitops.h index 9ffc35537024..c4c2173dfe99 100644 --- a/arch/riscv/include/asm/bitops.h +++ b/arch/riscv/include/asm/bitops.h @@ -22,6 +22,16 @@ #include <asm-generic/bitops/fls.h> #else +#define __HAVE_ARCH___FFS +#define __HAVE_ARCH___FLS +#define __HAVE_ARCH_FFS +#define __HAVE_ARCH_FLS + +#include <asm-generic/bitops/__ffs.h> +#include <asm-generic/bitops/__fls.h> +#include <asm-generic/bitops/ffs.h> +#include <asm-generic/bitops/fls.h> + #include <asm/alternative-macros.h> #include <asm/hwcap.h> @@ -37,8 +47,6 @@ static __always_inline unsigned long variable__ffs(unsigned long word) { - int num; - asm_volatile_goto(ALTERNATIVE("j %l[legacy]", "nop", 0, RISCV_ISA_EXT_ZBB, 1) : : : : legacy); @@ -52,32 +60,7 @@ static __always_inline unsigned long variable__ffs(unsigned long word) return word; legacy: - num = 0; -#if BITS_PER_LONG == 64 - if ((word & 0xffffffff) == 0) { - num += 32; - word >>= 32; - } -#endif - if ((word & 0xffff) == 0) { - num += 16; - word >>= 16; - } - if ((word & 0xff) == 0) { - num += 8; - word >>= 8; - } - if ((word & 0xf) == 0) { - num += 4; - word >>= 4; - } - if ((word & 0x3) == 0) { - num += 2; - word >>= 2; - } - if ((word & 0x1) == 0) - num += 1; - return num; + return generic___ffs(word); } /** @@ -93,8 +76,6 @@ legacy: static __always_inline unsigned long variable__fls(unsigned long word) { - int num; - asm_volatile_goto(ALTERNATIVE("j %l[legacy]", "nop", 0, RISCV_ISA_EXT_ZBB, 1) : : : : legacy); @@ -108,32 +89,7 @@ static __always_inline unsigned long variable__fls(unsigned long word) return BITS_PER_LONG - 1 - word; legacy: - num = BITS_PER_LONG - 1; -#if BITS_PER_LONG == 64 - if (!(word & (~0ul << 32))) { - num -= 32; - word <<= 32; - } -#endif - if (!(word & (~0ul << (BITS_PER_LONG - 16)))) { - num -= 16; - word <<= 16; - } - if (!(word & (~0ul << (BITS_PER_LONG - 8)))) { - num -= 8; - word <<= 8; - } - if (!(word & (~0ul << (BITS_PER_LONG - 4)))) { - num -= 4; - word <<= 4; - } - if (!(word & (~0ul << (BITS_PER_LONG - 2)))) { - num -= 2; - word <<= 2; - } - if (!(word & (~0ul << (BITS_PER_LONG - 1)))) - num -= 1; - return num; + return generic___fls(word); } /** @@ -149,46 +105,23 @@ legacy: static __always_inline int variable_ffs(int x) { - int r; - - if (!x) - return 0; - asm_volatile_goto(ALTERNATIVE("j %l[legacy]", "nop", 0, RISCV_ISA_EXT_ZBB, 1) : : : : legacy); + if (!x) + return 0; + asm volatile (".option push\n" ".option arch,+zbb\n" CTZW "%0, %1\n" ".option pop\n" - : "=r" (r) : "r" (x) :); + : "=r" (x) : "r" (x) :); - return r + 1; + return x + 1; legacy: - r = 1; - if (!(x & 0xffff)) { - x >>= 16; - r += 16; - } - if (!(x & 0xff)) { - x >>= 8; - r += 8; - } - if (!(x & 0xf)) { - x >>= 4; - r += 4; - } - if (!(x & 3)) { - x >>= 2; - r += 2; - } - if (!(x & 1)) { - x >>= 1; - r += 1; - } - return r; + return generic_ffs(x); } /** @@ -204,46 +137,23 @@ legacy: static __always_inline int variable_fls(unsigned int x) { - int r; - - if (!x) - return 0; - asm_volatile_goto(ALTERNATIVE("j %l[legacy]", "nop", 0, RISCV_ISA_EXT_ZBB, 1) : : : : legacy); + if (!x) + return 0; + asm volatile (".option push\n" ".option arch,+zbb\n" CLZW "%0, %1\n" ".option pop\n" - : "=r" (r) : "r" (x) :); + : "=r" (x) : "r" (x) :); - return 32 - r; + return 32 - x; legacy: - r = 32; - if (!(x & 0xffff0000u)) { - x <<= 16; - r -= 16; - } - if (!(x & 0xff000000u)) { - x <<= 8; - r -= 8; - } - if (!(x & 0xf0000000u)) { - x <<= 4; - r -= 4; - } - if (!(x & 0xc0000000u)) { - x <<= 2; - r -= 2; - } - if (!(x & 0x80000000u)) { - x <<= 1; - r -= 1; - } - return r; + return generic_fls(x); } /** |