99 lines
1.9 KiB
C
99 lines
1.9 KiB
C
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/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Userspace port (c) 2019 Hak5
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*/
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#ifndef __USERSPACE_BITOPS_H__
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#define __USERSPACE_BITOPS_H__
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#include "kernel/bits.h"
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#include "kernel/types.h"
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#define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE)
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#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_TYPE(long))
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/**
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* __test_and_clear_bit - Clear a bit and return its old value
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* @nr: Bit to clear
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* @addr: Address to count from
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*
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* This operation is non-atomic and can be reordered.
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* If two examples of this operation race, one can appear to succeed
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* but actually fail. You must protect multiple accesses with a lock.
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*/
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static inline int __test_and_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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unsigned long old = *p;
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*p = old & ~mask;
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return (old & mask) != 0;
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}
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#define test_and_clear_bit(nr, addr) __test_and_clear_bit((nr), (addr))
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/*
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* Kluge swab16
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*/
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static inline __u16 ___swab16(__u16 x)
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{
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return x<<8 | x>>8;
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}
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#define swab16(x) ___swab16(x)
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/*
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* Kluge FLS from generic
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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 int __fls(unsigned 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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static int __fls64(__u64 x)
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{
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__u32 h = x >> 32;
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if (h)
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return __fls(h) + 32;
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return __fls(x);
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}
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#define __fls_long(x) __fls64(x)
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#endif /* ifndef USERSPACE_BITOPS_H */
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