124 lines
2.7 KiB
C
124 lines
2.7 KiB
C
/*
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* include/asm-xtensa/bitops.h
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*
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* Atomic operations that C can't guarantee us.Useful for resource counting etc.
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 2001 - 2005 Tensilica Inc.
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*/
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#ifndef _XTENSA_BITOPS_H
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#define _XTENSA_BITOPS_H
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#ifdef __KERNEL__
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#include <asm/processor.h>
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#include <asm/byteorder.h>
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#include <asm/system.h>
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#ifdef CONFIG_SMP
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# error SMP not supported on this architecture
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#endif
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#define smp_mb__before_clear_bit() barrier()
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#define smp_mb__after_clear_bit() barrier()
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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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#if XCHAL_HAVE_NSA
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static __inline__ int __cntlz (unsigned long x)
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{
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int lz;
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asm ("nsau %0, %1" : "=r" (lz) : "r" (x));
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return 31 - lz;
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}
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#else
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static __inline__ int __cntlz (unsigned long x)
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{
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unsigned long sum, x1, x2, x4, x8, x16;
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x1 = x & 0xAAAAAAAA;
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x2 = x & 0xCCCCCCCC;
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x4 = x & 0xF0F0F0F0;
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x8 = x & 0xFF00FF00;
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x16 = x & 0xFFFF0000;
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sum = x2 ? 2 : 0;
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sum += (x16 != 0) * 16;
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sum += (x8 != 0) * 8;
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sum += (x4 != 0) * 4;
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sum += (x1 != 0);
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return sum;
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}
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#endif
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/*
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* ffz: Find first zero in word. Undefined if no zero exists.
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* bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
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*/
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static __inline__ int ffz(unsigned long x)
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{
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if ((x = ~x) == 0)
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return 32;
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return __cntlz(x & -x);
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}
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/*
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* __ffs: Find first bit set in word. Return 0 for bit 0
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*/
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static __inline__ int __ffs(unsigned long x)
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{
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return __cntlz(x & -x);
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}
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/*
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* ffs: Find first bit set in word. 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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*/
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static __inline__ int ffs(unsigned long x)
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{
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return __cntlz(x & -x) + 1;
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}
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/*
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* fls: Find last (most-significant) bit set in word.
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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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return __cntlz(x);
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}
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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/ext2-non-atomic.h>
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#ifdef __XTENSA_EL__
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# define ext2_set_bit_atomic(lock,nr,addr) test_and_set_bit((nr),(addr))
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# define ext2_clear_bit_atomic(lock,nr,addr) test_and_clear_bit((nr),(addr))
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#elif defined(__XTENSA_EB__)
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# define ext2_set_bit_atomic(lock,nr,addr) test_and_set_bit((nr) ^ 0x18, (addr))
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# define ext2_clear_bit_atomic(lock,nr,addr) test_and_clear_bit((nr)^0x18,(addr))
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#else
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# error processor byte order undefined!
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#endif
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#include <asm-generic/bitops/hweight.h>
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#include <asm-generic/bitops/sched.h>
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#include <asm-generic/bitops/minix.h>
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#endif /* __KERNEL__ */
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#endif /* _XTENSA_BITOPS_H */
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