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3fc2579e6f
When testing in userspace, UBSAN pointed out that shifting into the sign bit is undefined behaviour. It doesn't really make sense to ask for the highest set bit of a negative value, so just turn the argument type into an unsigned int. Some architectures (eg ppc) already had it declared as an unsigned int, so I don't expect too many problems. Link: http://lkml.kernel.org/r/20181105221117.31828-1-willy@infradead.org Signed-off-by: Matthew Wilcox <willy@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
83 lines
1.4 KiB
C
83 lines
1.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
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#ifndef __ASM_CSKY_BITOPS_H
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#define __ASM_CSKY_BITOPS_H
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#include <linux/compiler.h>
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#include <asm/barrier.h>
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/*
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* asm-generic/bitops/ffs.h
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*/
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static inline int ffs(int x)
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{
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if (!x)
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return 0;
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asm volatile (
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"brev %0\n"
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"ff1 %0\n"
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"addi %0, 1\n"
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: "=&r"(x)
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: "0"(x));
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return x;
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}
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/*
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* asm-generic/bitops/__ffs.h
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*/
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static __always_inline unsigned long __ffs(unsigned long x)
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{
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asm volatile (
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"brev %0\n"
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"ff1 %0\n"
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: "=&r"(x)
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: "0"(x));
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return x;
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}
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/*
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* asm-generic/bitops/fls.h
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*/
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static __always_inline int fls(unsigned int x)
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{
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asm volatile(
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"ff1 %0\n"
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: "=&r"(x)
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: "0"(x));
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return (32 - x);
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}
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/*
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* asm-generic/bitops/__fls.h
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*/
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static __always_inline unsigned long __fls(unsigned long x)
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{
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return fls(x) - 1;
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}
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#include <asm-generic/bitops/ffz.h>
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#include <asm-generic/bitops/fls64.h>
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#include <asm-generic/bitops/find.h>
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#ifndef _LINUX_BITOPS_H
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#error only <linux/bitops.h> can be included directly
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#endif
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#include <asm-generic/bitops/sched.h>
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#include <asm-generic/bitops/hweight.h>
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#include <asm-generic/bitops/lock.h>
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#include <asm-generic/bitops/atomic.h>
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/*
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* bug fix, why only could use atomic!!!!
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*/
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#include <asm-generic/bitops/non-atomic.h>
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#define __clear_bit(nr, vaddr) clear_bit(nr, vaddr)
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#include <asm-generic/bitops/le.h>
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#include <asm-generic/bitops/ext2-atomic.h>
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#endif /* __ASM_CSKY_BITOPS_H */
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