/* * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2019 Western Digital Corporation or its affiliates. * * Authors: * Atish Patra */ #ifndef __SBI_BITOPS_H__ #define __SBI_BITOPS_H__ #include #if __SIZEOF_POINTER__ == 8 #define BITS_PER_LONG 64 #elif __SIZEOF_POINTER__ == 4 #define BITS_PER_LONG 32 #else #error "Unexpected __SIZEOF_POINTER__" #endif #define EXTRACT_FIELD(val, which) \ (((val) & (which)) / ((which) & ~((which)-1))) #define INSERT_FIELD(val, which, fieldval) \ (((val) & ~(which)) | ((fieldval) * ((which) & ~((which)-1)))) #define BITS_TO_LONGS(nbits) (((nbits) + BITS_PER_LONG - 1) / \ BITS_PER_LONG) #define BIT(nr) (1UL << (nr)) #define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG)) #define BIT_WORD(bit) ((bit) / BITS_PER_LONG) #define BIT_WORD_OFFSET(bit) ((bit) & (BITS_PER_LONG - 1)) #define GENMASK(h, l) \ (((~0UL) - (1UL << (l)) + 1) & (~0UL >> (BITS_PER_LONG - 1 - (h)))) /** * 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 the above ffz (man ffs). */ static inline int ffs(int x) { int r = 1; if (!x) return 0; 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)) r += 1; return r; } /** * __ffs - find first bit in word. * @word: The word to search * * Undefined if no bit exists, so code should check against 0 first. */ static inline int __ffs(unsigned long word) { int 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; } /* * ffz - find first zero in word. * @word: The word to search * * Undefined if no zero exists, so code should check against ~0UL first. */ #define ffz(x) __ffs(~(x)) /** * 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 inline int fls(int x) { int r = 32; if (!x) return 0; 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)) r -= 1; return r; } /** * __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 inline unsigned long __fls(unsigned long word) { int 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; } #define for_each_set_bit(bit, addr, size) \ for ((bit) = find_first_bit((addr), (size)); \ (bit) < (size); \ (bit) = find_next_bit((addr), (size), (bit) + 1)) /* same as for_each_set_bit() but use bit as value to start with */ #define for_each_set_bit_from(bit, addr, size) \ for ((bit) = find_next_bit((addr), (size), (bit)); \ (bit) < (size); \ (bit) = find_next_bit((addr), (size), (bit) + 1)) #define for_each_clear_bit(bit, addr, size) \ for ((bit) = find_first_zero_bit((addr), (size)); \ (bit) < (size); \ (bit) = find_next_zero_bit((addr), (size), (bit) + 1)) /* same as for_each_clear_bit() but use bit as value to start with */ #define for_each_clear_bit_from(bit, addr, size) \ for ((bit) = find_next_zero_bit((addr), (size), (bit)); \ (bit) < (size); \ (bit) = find_next_zero_bit((addr), (size), (bit) + 1)) unsigned long find_first_bit(const unsigned long *addr, unsigned long size); unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size); unsigned long find_last_bit(const unsigned long *addr, unsigned long size); unsigned long find_next_bit(const unsigned long *addr, unsigned long size, unsigned long offset); unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size, unsigned long offset); /** * __set_bit - Set a bit in memory * @nr: the bit to set * @addr: the address to start counting from * * This function is non-atomic and may be reordered. */ static inline void __set_bit(int nr, volatile unsigned long *addr) { unsigned long mask = BIT_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); *p |= mask; } /** * __clear_bit - Clear a bit in memory * @nr: the bit to clear * @addr: the address to start counting from * * This function is non-atomic and may be reordered. */ static inline void __clear_bit(int nr, volatile unsigned long *addr) { unsigned long mask = BIT_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); *p &= ~mask; } /** * __change_bit - Toggle a bit in memory * @nr: the bit to change * @addr: the address to start counting from * * This function is non-atomic and may be reordered. */ static inline void __change_bit(int nr, volatile unsigned long *addr) { unsigned long mask = BIT_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); *p ^= mask; } /** * __test_and_set_bit - Set a bit and return its old value * @nr: Bit to set * @addr: Address to count from * * This operation is non-atomic and can be reordered. */ static inline int __test_and_set_bit(int nr, volatile unsigned long *addr) { unsigned long mask = BIT_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); unsigned long old = *p; *p = old | mask; return (old & mask) != 0; } /** * __test_and_clear_bit - Clear a bit and return its old value * @nr: Bit to clear * @addr: Address to count from * * This operation is non-atomic and can be reordered. */ static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr) { unsigned long mask = BIT_MASK(nr); unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); unsigned long old = *p; *p = old & ~mask; return (old & mask) != 0; } /** * __test_bit - Determine whether a bit is set * @nr: bit number to test * @addr: Address to start counting from * * This operation is non-atomic and can be reordered. */ static inline int __test_bit(int nr, const volatile unsigned long *addr) { return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-1))); } #endif