/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_BITOPS_H
#define _LINUX_BITOPS_H

#include <asm/types.h>
#include <linux/bits.h>

#include <uapi/linux/kernel.h>

/* Set bits in the first 'n' bytes when loaded from memory */
#ifdef __LITTLE_ENDIAN
#  define aligned_byte_mask(n) ((1UL << 8*(n))-1)
#else
#  define aligned_byte_mask(n) (~0xffUL << (BITS_PER_LONG - 8 - 8*(n)))
#endif

#define BITS_PER_TYPE(type)     (sizeof(type) * BITS_PER_BYTE)
#define BITS_TO_LONGS(nr)       __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(long))
#define BITS_TO_U64(nr)         __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u64))
#define BITS_TO_U32(nr)         __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u32))
#define BITS_TO_BYTES(nr)       __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(char))

extern unsigned int __sw_hweight8(unsigned int w);
extern unsigned int __sw_hweight16(unsigned int w);
extern unsigned int __sw_hweight32(unsigned int w);
extern unsigned long __sw_hweight64(__u64 w);

/*
 * Include this here because some architectures need generic_ffs/fls in
 * scope
 */
#include <asm/bitops.h>

#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))

/**
 * for_each_set_clump8 - iterate over bitmap for each 8-bit clump with set bits
 * @start: bit offset to start search and to store the current iteration offset
 * @clump: location to store copy of current 8-bit clump
 * @bits: bitmap address to base the search on
 * @size: bitmap size in number of bits
 */
#define for_each_set_clump8(start, clump, bits, size) \
        for ((start) = find_first_clump8(&(clump), (bits), (size)); \
             (start) < (size); \
             (start) = find_next_clump8(&(clump), (bits), (size), (start) + 8))

static inline int get_bitmask_order(unsigned int count)
{
        int order;

        order = fls(count);
        return order;   /* We could be slightly more clever with -1 here... */
}

static __always_inline unsigned long hweight_long(unsigned long w)
{
        return sizeof(w) == 4 ? hweight32(w) : hweight64((__u64)w);
}

/**
 * rol64 - rotate a 64-bit value left
 * @word: value to rotate
 * @shift: bits to roll
 */
static inline __u64 rol64(__u64 word, unsigned int shift)
{
        return (word << (shift & 63)) | (word >> ((-shift) & 63));
}

/**
 * ror64 - rotate a 64-bit value right
 * @word: value to rotate
 * @shift: bits to roll
 */
static inline __u64 ror64(__u64 word, unsigned int shift)
{
        return (word >> (shift & 63)) | (word << ((-shift) & 63));
}

/**
 * rol32 - rotate a 32-bit value left
 * @word: value to rotate
 * @shift: bits to roll
 */
static inline __u32 rol32(__u32 word, unsigned int shift)
{
        return (word << (shift & 31)) | (word >> ((-shift) & 31));
}

/**
 * ror32 - rotate a 32-bit value right
 * @word: value to rotate
 * @shift: bits to roll
 */
static inline __u32 ror32(__u32 word, unsigned int shift)
{
        return (word >> (shift & 31)) | (word << ((-shift) & 31));
}

/**
 * rol16 - rotate a 16-bit value left
 * @word: value to rotate
 * @shift: bits to roll
 */
static inline __u16 rol16(__u16 word, unsigned int shift)
{
        return (word << (shift & 15)) | (word >> ((-shift) & 15));
}

/**
 * ror16 - rotate a 16-bit value right
 * @word: value to rotate
 * @shift: bits to roll
 */
static inline __u16 ror16(__u16 word, unsigned int shift)
{
        return (word >> (shift & 15)) | (word << ((-shift) & 15));
}

/**
 * rol8 - rotate an 8-bit value left
 * @word: value to rotate
 * @shift: bits to roll
 */
static inline __u8 rol8(__u8 word, unsigned int shift)
{
        return (word << (shift & 7)) | (word >> ((-shift) & 7));
}

/**
 * ror8 - rotate an 8-bit value right
 * @word: value to rotate
 * @shift: bits to roll
 */
static inline __u8 ror8(__u8 word, unsigned int shift)
{
        return (word >> (shift & 7)) | (word << ((-shift) & 7));
}

/**
 * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
 * @value: value to sign extend
 * @index: 0 based bit index (0<=index<32) to sign bit
 *
 * This is safe to use for 16- and 8-bit types as well.
 */
static __always_inline __s32 sign_extend32(__u32 value, int index)
{
        __u8 shift = 31 - index;
        return (__s32)(value << shift) >> shift;
}

/**
 * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
 * @value: value to sign extend
 * @index: 0 based bit index (0<=index<64) to sign bit
 */
static __always_inline __s64 sign_extend64(__u64 value, int index)
{
        __u8 shift = 63 - index;
        return (__s64)(value << shift) >> shift;
}

static inline unsigned fls_long(unsigned long l)
{
        if (sizeof(l) == 4)
                return fls(l);
        return fls64(l);
}

static inline int get_count_order(unsigned int count)
{
        if (count == 0)
                return -1;

        return fls(--count);
}

/**
 * get_count_order_long - get order after rounding @l up to power of 2
 * @l: parameter
 *
 * it is same as get_count_order() but with long type parameter
 */
static inline int get_count_order_long(unsigned long l)
{
        if (l == 0UL)
                return -1;
        return (int)fls_long(--l);
}

/**
 * __ffs64 - find first set bit in a 64 bit word
 * @word: The 64 bit word
 *
 * On 64 bit arches this is a synonym for __ffs
 * The result is not defined if no bits are set, so check that @word
 * is non-zero before calling this.
 */
static inline unsigned long __ffs64(u64 word)
{
#if BITS_PER_LONG == 32
        if (((u32)word) == 0UL)
                return __ffs((u32)(word >> 32)) + 32;
#elif BITS_PER_LONG != 64
#error BITS_PER_LONG not 32 or 64
#endif
        return __ffs((unsigned long)word);
}

/**
 * assign_bit - Assign value to a bit in memory
 * @nr: the bit to set
 * @addr: the address to start counting from
 * @value: the value to assign
 */
static __always_inline void assign_bit(long nr, volatile unsigned long *addr,
                                       bool value)
{
        if (value)
                set_bit(nr, addr);
        else
                clear_bit(nr, addr);
}

static __always_inline void __assign_bit(long nr, volatile unsigned long *addr,
                                         bool value)
{
        if (value)
                __set_bit(nr, addr);
        else
                __clear_bit(nr, addr);
}

#ifdef __KERNEL__

#ifndef set_mask_bits
#define set_mask_bits(ptr, mask, bits)  \
({                                                              \
        const typeof(*(ptr)) mask__ = (mask), bits__ = (bits);  \
        typeof(*(ptr)) old__, new__;                            \
                                                                \
        do {                                                    \
                old__ = READ_ONCE(*(ptr));                      \
                new__ = (old__ & ~mask__) | bits__;             \
        } while (cmpxchg(ptr, old__, new__) != old__);          \
                                                                \
        old__;                                                  \
})
#endif

#ifndef bit_clear_unless
#define bit_clear_unless(ptr, clear, test)      \
({                                                              \
        const typeof(*(ptr)) clear__ = (clear), test__ = (test);\
        typeof(*(ptr)) old__, new__;                            \
                                                                \
        do {                                                    \
                old__ = READ_ONCE(*(ptr));                      \
                new__ = old__ & ~clear__;                       \
        } while (!(old__ & test__) &&                           \
                 cmpxchg(ptr, old__, new__) != old__);          \
                                                                \
        !(old__ & test__);                                      \
})
#endif

#endif /* __KERNEL__ */
#endif