[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v7 05/19] xen/bitops: implement fls{l}() in common logic
Return type was left 'int' because of the following compilation error: ./include/xen/kernel.h:18:21: error: comparison of distinct pointer types lacks a cast [-Werror] 18 | (void) (&_x == &_y); \ | ^~ common/page_alloc.c:1843:34: note: in expansion of macro 'min' 1843 | unsigned int inc_order = min(MAX_ORDER, flsl(e - s) - 1); generic_fls{l} was used instead of __builtin_clz{l}(x) as if x is 0, the result in undefined. Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx> --- Changes in V7: - Code style fixes --- Changes in V6: - new patch for the patch series. --- xen/arch/arm/include/asm/arm32/bitops.h | 2 +- xen/arch/arm/include/asm/arm64/bitops.h | 6 ++---- xen/arch/arm/include/asm/bitops.h | 7 ++----- xen/arch/x86/include/asm/bitops.h | 6 ++++-- xen/common/bitops.c | 22 ++++++++++++++++++++++ xen/include/xen/bitops.h | 4 ++-- 6 files changed, 33 insertions(+), 14 deletions(-) diff --git a/xen/arch/arm/include/asm/arm32/bitops.h b/xen/arch/arm/include/asm/arm32/bitops.h index d0309d47c1..5552d4e945 100644 --- a/xen/arch/arm/include/asm/arm32/bitops.h +++ b/xen/arch/arm/include/asm/arm32/bitops.h @@ -1,7 +1,7 @@ #ifndef _ARM_ARM32_BITOPS_H #define _ARM_ARM32_BITOPS_H -#define flsl fls +#define arch_flsl fls /* * Little endian assembly bitops. nr = 0 -> byte 0 bit 0. diff --git a/xen/arch/arm/include/asm/arm64/bitops.h b/xen/arch/arm/include/asm/arm64/bitops.h index 0efde29068..5f5d97faa0 100644 --- a/xen/arch/arm/include/asm/arm64/bitops.h +++ b/xen/arch/arm/include/asm/arm64/bitops.h @@ -22,17 +22,15 @@ static /*__*/always_inline unsigned long __ffs(unsigned long word) */ #define ffz(x) __ffs(~(x)) -static inline int flsl(unsigned long x) +static inline int arch_flsl(unsigned long x) { uint64_t ret; - if (__builtin_constant_p(x)) - return generic_flsl(x); - asm("clz\t%0, %1" : "=r" (ret) : "r" (x)); return BITS_PER_LONG - ret; } +#define arch_flsl arch_flsl /* Based on linux/include/asm-generic/bitops/find.h */ diff --git a/xen/arch/arm/include/asm/bitops.h b/xen/arch/arm/include/asm/bitops.h index 8e16335e76..860d6d4689 100644 --- a/xen/arch/arm/include/asm/bitops.h +++ b/xen/arch/arm/include/asm/bitops.h @@ -78,17 +78,14 @@ bool clear_mask16_timeout(uint16_t mask, volatile void *p, * the clz instruction for much better code efficiency. */ -static inline int fls(unsigned int x) +static inline int arch_fls(unsigned int x) { int ret; - if (__builtin_constant_p(x)) - return generic_fls(x); - asm("clz\t%"__OP32"0, %"__OP32"1" : "=r" (ret) : "r" (x)); return 32 - ret; } - +#define arch_fls arch_fls #define arch_ffs(x) ({ unsigned int __t = (x); fls(ISOLATE_LSB(__t)); }) #define arch_ffsl(x) ({ unsigned long __t = (x); flsl(ISOLATE_LSB(__t)); }) diff --git a/xen/arch/x86/include/asm/bitops.h b/xen/arch/x86/include/asm/bitops.h index 81b43da5db..9c4ab52df7 100644 --- a/xen/arch/x86/include/asm/bitops.h +++ b/xen/arch/x86/include/asm/bitops.h @@ -428,7 +428,7 @@ static always_inline unsigned int arch_ffsl(unsigned long x) * * This is defined the same way as ffs. */ -static inline int flsl(unsigned long x) +static always_inline int arch_flsl(unsigned long x) { long r; @@ -438,8 +438,9 @@ static inline int flsl(unsigned long x) "1:" : "=r" (r) : "rm" (x)); return (int)r+1; } +#define arch_flsl arch_flsl -static inline int fls(unsigned int x) +static always_inline int arch_fls(unsigned int x) { int r; @@ -449,6 +450,7 @@ static inline int fls(unsigned int x) "1:" : "=r" (r) : "rm" (x)); return r + 1; } +#define arch_fls arch_fls /** * hweightN - returns the hamming weight of a N-bit word diff --git a/xen/common/bitops.c b/xen/common/bitops.c index a8c32f6767..95bc47176b 100644 --- a/xen/common/bitops.c +++ b/xen/common/bitops.c @@ -62,9 +62,31 @@ static void test_ffs(void) CHECK(ffs64, (uint64_t)0x8000000000000000, 64); } +static void test_fls(void) +{ + /* unsigned int ffs(unsigned int) */ + CHECK(fls, 1, 1); + CHECK(fls, 3, 2); + CHECK(fls, 3U << 30, 32); + + /* unsigned int flsl(unsigned long) */ + CHECK(flsl, 1, 1); + CHECK(flsl, 1UL << (BITS_PER_LONG - 1), BITS_PER_LONG); +#if BITS_PER_LONG > 32 + CHECK(flsl, 3UL << 32, 34); +#endif + + /* unsigned int fls64(uint64_t) */ + CHECK(fls64, 1, 1); + CHECK(fls64, 0x00000000C0000000ULL, 32); + CHECK(fls64, 0x0000000180000000ULL, 33); + CHECK(fls64, 0xC000000000000000ULL, 64); +} + static int __init cf_check test_bitops(void) { test_ffs(); + test_fls(); return 0; } diff --git a/xen/include/xen/bitops.h b/xen/include/xen/bitops.h index 685c7540cc..bc8ae53997 100644 --- a/xen/include/xen/bitops.h +++ b/xen/include/xen/bitops.h @@ -201,7 +201,7 @@ static always_inline __pure int test_bit(int nr, const volatile void *addr) static always_inline __pure int fls(unsigned int x) { - if (__builtin_constant_p(x)) + if ( __builtin_constant_p(x) ) return generic_fls(x); #ifndef arch_fls @@ -213,7 +213,7 @@ static always_inline __pure int fls(unsigned int x) static always_inline __pure int flsl(unsigned long x) { - if (__builtin_constant_p(x)) + if ( __builtin_constant_p(x) ) return generic_flsl(x); #ifndef arch_flsl -- 2.43.0
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