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202 lines
4.3 KiB
202 lines
4.3 KiB
#ifndef _LINUX_BITOPS_H |
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#define _LINUX_BITOPS_H |
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#include <asm/types.h> |
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#include <asm-generic/bitsperlong.h> |
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#include <linux/compiler.h> |
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#ifdef __KERNEL__ |
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#define BIT(nr) (1UL << (nr)) |
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#define BIT_ULL(nr) (1ULL << (nr)) |
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#define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG)) |
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#define BIT_WORD(nr) ((nr) / BITS_PER_LONG) |
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#define BIT_ULL_MASK(nr) (1ULL << ((nr) % BITS_PER_LONG_LONG)) |
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#define BIT_ULL_WORD(nr) ((nr) / BITS_PER_LONG_LONG) |
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#define BITS_PER_BYTE 8 |
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#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long)) |
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#endif |
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/* |
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* Create a contiguous bitmask starting at bit position @l and ending at |
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* position @h. For example |
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* GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000. |
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*/ |
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#define GENMASK(h, l) \ |
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(((~0UL) << (l)) & (~0UL >> (BITS_PER_LONG - 1 - (h)))) |
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#define GENMASK_ULL(h, l) \ |
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(((~0ULL) << (l)) & (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h)))) |
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/* |
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* ffs: find first bit set. This is defined the same way as |
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* the libc and compiler builtin ffs routines, therefore |
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* differs in spirit from the above ffz (man ffs). |
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*/ |
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static inline int generic_ffs(int x) |
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{ |
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int r = 1; |
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if (!x) |
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return 0; |
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if (!(x & 0xffff)) { |
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x >>= 16; |
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r += 16; |
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} |
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if (!(x & 0xff)) { |
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x >>= 8; |
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r += 8; |
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} |
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if (!(x & 0xf)) { |
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x >>= 4; |
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r += 4; |
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} |
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if (!(x & 3)) { |
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x >>= 2; |
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r += 2; |
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} |
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if (!(x & 1)) { |
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x >>= 1; |
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r += 1; |
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} |
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return r; |
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} |
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/** |
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* fls - find last (most-significant) bit set |
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* @x: the word to search |
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* |
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* This is defined the same way as ffs. |
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* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. |
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*/ |
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static inline int generic_fls(int x) |
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{ |
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int r = 32; |
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if (!x) |
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return 0; |
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if (!(x & 0xffff0000u)) { |
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x <<= 16; |
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r -= 16; |
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} |
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if (!(x & 0xff000000u)) { |
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x <<= 8; |
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r -= 8; |
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} |
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if (!(x & 0xf0000000u)) { |
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x <<= 4; |
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r -= 4; |
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} |
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if (!(x & 0xc0000000u)) { |
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x <<= 2; |
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r -= 2; |
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} |
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if (!(x & 0x80000000u)) { |
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x <<= 1; |
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r -= 1; |
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} |
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return r; |
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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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*/ |
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static inline unsigned int generic_hweight32(unsigned int w) |
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{ |
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unsigned int res = (w & 0x55555555) + ((w >> 1) & 0x55555555); |
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res = (res & 0x33333333) + ((res >> 2) & 0x33333333); |
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res = (res & 0x0F0F0F0F) + ((res >> 4) & 0x0F0F0F0F); |
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res = (res & 0x00FF00FF) + ((res >> 8) & 0x00FF00FF); |
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return (res & 0x0000FFFF) + ((res >> 16) & 0x0000FFFF); |
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} |
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static inline unsigned int generic_hweight16(unsigned int w) |
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{ |
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unsigned int res = (w & 0x5555) + ((w >> 1) & 0x5555); |
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res = (res & 0x3333) + ((res >> 2) & 0x3333); |
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res = (res & 0x0F0F) + ((res >> 4) & 0x0F0F); |
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return (res & 0x00FF) + ((res >> 8) & 0x00FF); |
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} |
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static inline unsigned int generic_hweight8(unsigned int w) |
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{ |
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unsigned int res = (w & 0x55) + ((w >> 1) & 0x55); |
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res = (res & 0x33) + ((res >> 2) & 0x33); |
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return (res & 0x0F) + ((res >> 4) & 0x0F); |
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} |
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#include <asm/bitops.h> |
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/* linux/include/asm-generic/bitops/non-atomic.h */ |
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#ifndef PLATFORM__SET_BIT |
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# define __set_bit generic_set_bit |
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#endif |
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#ifndef PLATFORM__CLEAR_BIT |
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# define __clear_bit generic_clear_bit |
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#endif |
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#ifndef PLATFORM_FFS |
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# define ffs generic_ffs |
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#endif |
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#ifndef PLATFORM_FLS |
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# define fls generic_fls |
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#endif |
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static inline unsigned fls_long(unsigned long l) |
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{ |
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if (sizeof(l) == 4) |
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return fls(l); |
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return fls64(l); |
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} |
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/** |
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* __ffs64 - find first set bit in a 64 bit word |
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* @word: The 64 bit word |
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* |
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* On 64 bit arches this is a synomyn for __ffs |
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* The result is not defined if no bits are set, so check that @word |
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* is non-zero before calling this. |
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*/ |
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static inline unsigned long __ffs64(u64 word) |
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{ |
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#if BITS_PER_LONG == 32 |
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if (((u32)word) == 0UL) |
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return __ffs((u32)(word >> 32)) + 32; |
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#elif BITS_PER_LONG != 64 |
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#error BITS_PER_LONG not 32 or 64 |
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#endif |
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return __ffs((unsigned long)word); |
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} |
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/** |
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* __set_bit - Set a bit in memory |
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* @nr: the bit to set |
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* @addr: the address to start counting from |
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* |
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* Unlike set_bit(), this function is non-atomic and may be reordered. |
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* If it's called on the same region of memory simultaneously, the effect |
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* may be that only one operation succeeds. |
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*/ |
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static inline void generic_set_bit(int nr, volatile unsigned long *addr) |
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{ |
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unsigned long mask = BIT_MASK(nr); |
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unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); |
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*p |= mask; |
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} |
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static inline void generic_clear_bit(int nr, volatile unsigned long *addr) |
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{ |
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unsigned long mask = BIT_MASK(nr); |
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unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); |
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*p &= ~mask; |
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} |
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#endif
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