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  • /*
     * Copyright 1995, Russell King.
     * Various bits and pieces copyrights include:
     *  Linus Torvalds (test_bit).
     *
     * Copyright (C) 2011 Andes Technology Corporation
     * Shawn Lin, Andes Technology Corporation <nobuhiro@andestech.com>
     *
     * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
     *
     * Please note that the code in this file should never be included
     * from user space.  Many of these are not implemented in assembler
     * since they would be too costly.  Also, they require priviledged
     * instructions (which are not available from user mode) to ensure
     * that they are atomic.
     */
    
    #ifndef __ASM_NDS_BITOPS_H
    #define __ASM_NDS_BITOPS_H
    
    #ifdef __KERNEL__
    
    #include <asm/system.h>
    
    #include <asm-generic/bitops/fls.h>
    #include <asm-generic/bitops/__fls.h>
    #include <asm-generic/bitops/fls64.h>
    #include <asm-generic/bitops/__ffs.h>
    
    
    #define smp_mb__before_clear_bit()	do { } while (0)
    #define smp_mb__after_clear_bit()	do { } while (0)
    
    /*
     * Function prototypes to keep gcc -Wall happy.
     */
    extern void set_bit(int nr, void *addr);
    
    static inline void __set_bit(int nr, void *addr)
    {
    	int *a = (int *)addr;
    	int mask;
    
    	a += nr >> 5;
    	mask = 1 << (nr & 0x1f);
    	*a |= mask;
    }
    
    extern void clear_bit(int nr, void *addr);
    
    static inline void __clear_bit(int nr, void *addr)
    {
    	int *a = (int *)addr;
    	int mask;
    	unsigned long flags;
    
    	a += nr >> 5;
    	mask = 1 << (nr & 0x1f);
    	local_irq_save(flags);
    	*a &= ~mask;
    	local_irq_restore(flags);
    }
    
    extern void change_bit(int nr, void *addr);
    
    static inline void __change_bit(int nr, void *addr)
    {
    	int mask;
    	unsigned long *ADDR = (unsigned long *)addr;
    
    	ADDR += nr >> 5;
    	mask = 1 << (nr & 31);
    	*ADDR ^= mask;
    }
    
    extern int test_and_set_bit(int nr, void *addr);
    
    static inline int __test_and_set_bit(int nr, void *addr)
    {
    	int mask, retval;
    	unsigned int *a = (unsigned int *)addr;
    
    	a += nr >> 5;
    	mask = 1 << (nr & 0x1f);
    	retval = (mask & *a) != 0;
    	*a |= mask;
    	return retval;
    }
    
    extern int test_and_clear_bit(int nr, void *addr);
    
    static inline int __test_and_clear_bit(int nr, void *addr)
    {
    	int mask, retval;
    	unsigned int *a = (unsigned int *)addr;
    
    	a += nr >> 5;
    	mask = 1 << (nr & 0x1f);
    	retval = (mask & *a) != 0;
    	*a &= ~mask;
    	return retval;
    }
    
    extern int test_and_change_bit(int nr, void *addr);
    
    static inline int __test_and_change_bit(int nr, void *addr)
    {
    	int mask, retval;
    	unsigned int *a = (unsigned int *)addr;
    
    	a += nr >> 5;
    	mask = 1 << (nr & 0x1f);
    	retval = (mask & *a) != 0;
    	*a ^= mask;
    	return retval;
    }
    
    extern int find_first_zero_bit(void *addr, unsigned size);
    extern int find_next_zero_bit(void *addr, int size, int offset);
    
    /*
     * This routine doesn't need to be atomic.
     */
    static inline int test_bit(int nr, const void *addr)
    {
    	return ((unsigned char *) addr)[nr >> 3] & (1U << (nr & 7));
    }
    
    /*
     * ffz = Find First Zero in word. Undefined if no zero exists,
     * so code should check against ~0UL first..
     */
    static inline unsigned long ffz(unsigned long word)
    {
    	int k;
    
    	word = ~word;
    	k = 31;
    	if (word & 0x0000ffff) {
    		k -= 16; word <<= 16;
    	}
    	if (word & 0x00ff0000) {
    		k -= 8;  word <<= 8;
    	}
    	if (word & 0x0f000000) {
    		k -= 4;  word <<= 4;
    	}
    	if (word & 0x30000000) {
    		k -= 2;  word <<= 2;
    	}
    	if (word & 0x40000000)
    		k -= 1;
    
    	return k;
    }
    
    /*
     * ffs: find first bit set. This is defined the same way as
     * the libc and compiler builtin ffs routines, therefore
     * differs in spirit from the above ffz (man ffs).
     */
    
    /*
     * redefined in include/linux/bitops.h
     * #define ffs(x) generic_ffs(x)
     */
    
    /*
     * hweightN: returns the hamming weight (i.e. the number
     * of bits set) of a N-bit word
     */
    
    #define hweight32(x) generic_hweight32(x)
    #define hweight16(x) generic_hweight16(x)
    #define hweight8(x) generic_hweight8(x)
    
    #define ext2_set_bit			test_and_set_bit
    #define ext2_clear_bit			test_and_clear_bit
    #define ext2_test_bit			test_bit
    #define ext2_find_first_zero_bit	find_first_zero_bit
    #define ext2_find_next_zero_bit		find_next_zero_bit
    
    /* Bitmap functions for the minix filesystem. */
    #define minix_test_and_set_bit(nr, addr)	test_and_set_bit(nr, addr)
    #define minix_set_bit(nr, addr)			set_bit(nr, addr)
    #define minix_test_and_clear_bit(nr, addr)	test_and_clear_bit(nr, addr)
    #define minix_test_bit(nr, addr)		test_bit(nr, addr)
    #define minix_find_first_zero_bit(addr, size)	find_first_zero_bit(addr, size)
    
    #endif /* __KERNEL__ */
    
    #endif /* __ASM_NDS_BITOPS_H */