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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 <vitalya@ti.com>
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1 changed files with 40 additions and 3 deletions
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@ -95,9 +95,6 @@ static inline int __test_and_change_bit(int nr, volatile void *addr)
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return (old & mask) != 0;
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}
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extern int find_first_zero_bit(void * addr, unsigned size);
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extern int find_next_zero_bit(void * addr, int size, int offset);
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/*
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* This routine doesn't need to be atomic.
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*/
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@ -129,6 +126,43 @@ static inline unsigned long ffz(unsigned long word)
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return k;
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}
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static inline int find_next_zero_bit(void *addr, int size, int offset)
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{
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unsigned long *p = ((unsigned long *)addr) + (offset >> 5);
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unsigned long result = offset & ~31UL;
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unsigned long tmp;
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if (offset >= size)
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return size;
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size -= result;
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offset &= 31UL;
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if (offset) {
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tmp = *(p++);
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tmp |= ~0UL >> (32-offset);
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if (size < 32)
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goto found_first;
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if (~tmp)
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goto found_middle;
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size -= 32;
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result += 32;
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}
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while (size & ~31UL) {
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tmp = *(p++);
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if (~tmp)
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goto found_middle;
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result += 32;
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size -= 32;
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}
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if (!size)
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return result;
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tmp = *p;
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found_first:
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tmp |= ~0UL >> size;
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found_middle:
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return result + ffz(tmp);
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}
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/*
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* hweightN: returns the hamming weight (i.e. the number
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* of bits set) of a N-bit word
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@ -138,6 +172,9 @@ static inline unsigned long ffz(unsigned long word)
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#define hweight16(x) generic_hweight16(x)
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#define hweight8(x) generic_hweight8(x)
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#define find_first_zero_bit(addr, size) \
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find_next_zero_bit((addr), (size), 0)
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#define ext2_set_bit test_and_set_bit
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#define ext2_clear_bit test_and_clear_bit
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#define ext2_test_bit test_bit
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