From cb4ede926134a65bc3bf90ed58dace8451d7e759 Mon Sep 17 00:00:00 2001 From: Xiao Wang Date: Sun, 12 Nov 2023 17:44:21 +0800 Subject: [PATCH] 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 Signed-off-by: Xiao Wang Reviewed-by: Charlie Jenkins Link: https://lore.kernel.org/r/20231112094421.4014931-1-xiao.w.wang@intel.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/bitops.h | 138 +++++------------------------ include/asm-generic/bitops/__ffs.h | 8 +- include/asm-generic/bitops/__fls.h | 8 +- include/asm-generic/bitops/ffs.h | 8 +- include/asm-generic/bitops/fls.h | 8 +- 5 files changed, 48 insertions(+), 122 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 #else +#define __HAVE_ARCH___FFS +#define __HAVE_ARCH___FLS +#define __HAVE_ARCH_FFS +#define __HAVE_ARCH_FLS + +#include +#include +#include +#include + #include #include @@ -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 @@ static __always_inline unsigned long variable__ffs(unsigned long word) 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 @@ static __always_inline unsigned long variable__fls(unsigned long word) 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 @@ static __always_inline int variable_ffs(int x) 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); } /** diff --git a/include/asm-generic/bitops/__ffs.h b/include/asm-generic/bitops/__ffs.h index 39e56e1c7203..446fea6dda78 100644 --- a/include/asm-generic/bitops/__ffs.h +++ b/include/asm-generic/bitops/__ffs.h @@ -5,12 +5,12 @@ #include /** - * __ffs - find first bit in word. + * generic___ffs - find first bit in word. * @word: The word to search * * Undefined if no bit exists, so code should check against 0 first. */ -static __always_inline unsigned long __ffs(unsigned long word) +static __always_inline unsigned long generic___ffs(unsigned long word) { int num = 0; @@ -41,4 +41,8 @@ static __always_inline unsigned long __ffs(unsigned long word) return num; } +#ifndef __HAVE_ARCH___FFS +#define __ffs(word) generic___ffs(word) +#endif + #endif /* _ASM_GENERIC_BITOPS___FFS_H_ */ diff --git a/include/asm-generic/bitops/__fls.h b/include/asm-generic/bitops/__fls.h index 03f721a8a2b1..54ccccf96e21 100644 --- a/include/asm-generic/bitops/__fls.h +++ b/include/asm-generic/bitops/__fls.h @@ -5,12 +5,12 @@ #include /** - * __fls - find last (most-significant) set bit in a long word + * generic___fls - find last (most-significant) set bit in a long word * @word: the word to search * * Undefined if no set bit exists, so code should check against 0 first. */ -static __always_inline unsigned long __fls(unsigned long word) +static __always_inline unsigned long generic___fls(unsigned long word) { int num = BITS_PER_LONG - 1; @@ -41,4 +41,8 @@ static __always_inline unsigned long __fls(unsigned long word) return num; } +#ifndef __HAVE_ARCH___FLS +#define __fls(word) generic___fls(word) +#endif + #endif /* _ASM_GENERIC_BITOPS___FLS_H_ */ diff --git a/include/asm-generic/bitops/ffs.h b/include/asm-generic/bitops/ffs.h index 323fd5d6ae26..4c43f242daeb 100644 --- a/include/asm-generic/bitops/ffs.h +++ b/include/asm-generic/bitops/ffs.h @@ -3,14 +3,14 @@ #define _ASM_GENERIC_BITOPS_FFS_H_ /** - * ffs - find first bit set + * generic_ffs - find first bit set * @x: the word to search * * This is defined the same way as * the libc and compiler builtin ffs routines, therefore * differs in spirit from ffz (man ffs). */ -static inline int ffs(int x) +static inline int generic_ffs(int x) { int r = 1; @@ -39,4 +39,8 @@ static inline int ffs(int x) return r; } +#ifndef __HAVE_ARCH_FFS +#define ffs(x) generic_ffs(x) +#endif + #endif /* _ASM_GENERIC_BITOPS_FFS_H_ */ diff --git a/include/asm-generic/bitops/fls.h b/include/asm-generic/bitops/fls.h index b168bb10e1be..26f3ce1dd6e4 100644 --- a/include/asm-generic/bitops/fls.h +++ b/include/asm-generic/bitops/fls.h @@ -3,14 +3,14 @@ #define _ASM_GENERIC_BITOPS_FLS_H_ /** - * fls - find last (most-significant) bit set + * generic_fls - find last (most-significant) bit set * @x: the word to search * * This is defined the same way as ffs. * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. */ -static __always_inline int fls(unsigned int x) +static __always_inline int generic_fls(unsigned int x) { int r = 32; @@ -39,4 +39,8 @@ static __always_inline int fls(unsigned int x) return r; } +#ifndef __HAVE_ARCH_FLS +#define fls(x) generic_fls(x) +#endif + #endif /* _ASM_GENERIC_BITOPS_FLS_H_ */