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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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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>
99 lines
2.2 KiB
C
99 lines
2.2 KiB
C
/*
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* Port on Texas Instruments TMS320C6x architecture
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*
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* Copyright (C) 2004, 2009, 2010 Texas Instruments Incorporated
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* Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#ifndef _ASM_C6X_BITOPS_H
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#define _ASM_C6X_BITOPS_H
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#ifdef __KERNEL__
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#include <linux/bitops.h>
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#include <asm/byteorder.h>
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#include <asm/barrier.h>
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/*
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* We are lucky, DSP is perfect for bitops: do it in 3 cycles
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*/
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/**
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* __ffs - find first bit in word.
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* @word: The word to search
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*
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* Undefined if no bit exists, so code should check against 0 first.
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* Note __ffs(0) = undef, __ffs(1) = 0, __ffs(0x80000000) = 31.
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*
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*/
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static inline unsigned long __ffs(unsigned long x)
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{
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asm (" bitr .M1 %0,%0\n"
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" nop\n"
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" lmbd .L1 1,%0,%0\n"
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: "+a"(x));
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return x;
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}
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/*
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* ffz - find first zero in word.
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* @word: The word to search
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*
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* Undefined if no zero exists, so code should check against ~0UL first.
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*/
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#define ffz(x) __ffs(~(x))
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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 fls(unsigned int x)
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{
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if (!x)
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return 0;
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asm (" lmbd .L1 1,%0,%0\n" : "+a"(x));
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return 32 - x;
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}
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/**
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* ffs - find first 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
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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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* Note ffs(0) = 0, ffs(1) = 1, ffs(0x80000000) = 32.
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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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return __ffs(x) + 1;
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}
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#include <asm-generic/bitops/__fls.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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#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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#include <asm-generic/bitops/non-atomic.h>
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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 /* __KERNEL__ */
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#endif /* _ASM_C6X_BITOPS_H */
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