From: Vitaly Andrianov Date: Thu, 5 Feb 2015 16:24:46 +0000 (-0500) Subject: arm: implement find_next_zero_bit function X-Git-Tag: v2015.07-rc1~5^2~6 X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=81e9fe5a2988;p=oweals%2Fu-boot.git arm: implement find_next_zero_bit function This commit copies implementation of the find_next_zero_bit() from git://git.denx.de/u-boot.git/arch/mips/include/asm/bitops.h. v2014.07 The function is required to enable MCAST_TFTP support for ARM platforms. Signed-off-by: Vitaly Andrianov --- diff --git a/arch/arm/include/asm/bitops.h b/arch/arm/include/asm/bitops.h index 597dafbf9d..9b78043db7 100644 --- a/arch/arm/include/asm/bitops.h +++ b/arch/arm/include/asm/bitops.h @@ -95,9 +95,6 @@ static inline int __test_and_change_bit(int nr, volatile void *addr) return (old & mask) != 0; } -extern int find_first_zero_bit(void * addr, unsigned size); -extern int find_next_zero_bit(void * addr, int size, int offset); - /* * This routine doesn't need to be atomic. */ @@ -129,6 +126,43 @@ static inline unsigned long ffz(unsigned long word) return k; } +static inline int find_next_zero_bit(void *addr, int size, int offset) +{ + unsigned long *p = ((unsigned long *)addr) + (offset >> 5); + unsigned long result = offset & ~31UL; + unsigned long tmp; + + if (offset >= size) + return size; + size -= result; + offset &= 31UL; + if (offset) { + tmp = *(p++); + tmp |= ~0UL >> (32-offset); + if (size < 32) + goto found_first; + if (~tmp) + goto found_middle; + size -= 32; + result += 32; + } + while (size & ~31UL) { + tmp = *(p++); + if (~tmp) + goto found_middle; + result += 32; + size -= 32; + } + if (!size) + return result; + tmp = *p; + +found_first: + tmp |= ~0UL >> size; +found_middle: + return result + ffz(tmp); +} + /* * hweightN: returns the hamming weight (i.e. the number * of bits set) of a N-bit word @@ -138,6 +172,9 @@ static inline unsigned long ffz(unsigned long word) #define hweight16(x) generic_hweight16(x) #define hweight8(x) generic_hweight8(x) +#define find_first_zero_bit(addr, size) \ + find_next_zero_bit((addr), (size), 0) + #define ext2_set_bit test_and_set_bit #define ext2_clear_bit test_and_clear_bit #define ext2_test_bit test_bit