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/*

 * PowerPC64 atomic bit operations.

 * Dave Engebretsen, Todd Inglett, Don Reed, Pat McCarthy, Peter Bergner,

 * Anton Blanchard

 *

 * Originally taken from the 32b PPC code.  Modified to use 64b values for

 * the various counters & memory references.

 *

 * Bitops are odd when viewed on big-endian systems.  They were designed

 * on little endian so the size of the bitset doesn't matter (low order bytes

 * come first) as long as the bit in question is valid.

 *

 * Bits are "tested" often using the C expression (val & (1<<nr)) so we do

 * our best to stay compatible with that.  The assumption is that val will

 * be unsigned long for such tests.  As such, we assume the bits are stored

 * as an array of unsigned long (the usual case is a single unsigned long,

 * of course).  Here's an example bitset with bit numbering:

 *

 *   |63..........0|127........64|195.......128|255.......196|

 *

 * This leads to a problem. If an int, short or char is passed as a bitset

 * it will be a bad memory reference since we want to store in chunks

 * of unsigned long (64 bits here) size.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version

 * 2 of the License, or (at your option) any later version.

 */

#ifndef _PPC64_BITOPS_H

#define _PPC64_BITOPS_H

#ifdef __KERNEL__

#include <asm/memory.h>

/*

 * clear_bit doesn't imply a memory barrier

 */

#define smp_mb__before_clear_bit()      smp_mb()

#define smp_mb__after_clear_bit()       smp_mb()

static __inline__ int test_bit(unsigned long nr, __const__ volatile void *addr)

{

        return (1UL & (((__const__ long *) addr)[nr >> 6] >> (nr & 63)));

}

static __inline__ void set_bit(unsigned long nr, volatile void *addr)

{

        unsigned long old;

        unsigned long mask = 1UL << (nr & 0x3f);

        unsigned long *p = ((unsigned long *)addr) + (nr >> 6);

        __asm__ __volatile__(

"1:     ldarx   %0,0,%3         # set_bit\n\

        or      %0,%0,%2\n\

        stdcx.  %0,0,%3\n\

        bne-    1b"

        : "=&r" (old), "=m" (*p)

        : "r" (mask), "r" (p), "m" (*p)

        : "cc");

}

static __inline__ void clear_bit(unsigned long nr, volatile void *addr)

{

        unsigned long old;

        unsigned long mask = 1UL << (nr & 0x3f);

        unsigned long *p = ((unsigned long *)addr) + (nr >> 6);

        __asm__ __volatile__(

"1:     ldarx   %0,0,%3         # clear_bit\n\

        andc    %0,%0,%2\n\

        stdcx.  %0,0,%3\n\

        bne-    1b"

        : "=&r" (old), "=m" (*p)

        : "r" (mask), "r" (p), "m" (*p)

        : "cc");

}

static __inline__ void change_bit(unsigned long nr, volatile void *addr)

{

        unsigned long old;

        unsigned long mask = 1UL << (nr & 0x3f);

        unsigned long *p = ((unsigned long *)addr) + (nr >> 6);

        __asm__ __volatile__(

"1:     ldarx   %0,0,%3         # change_bit\n\

        xor     %0,%0,%2\n\

        stdcx.  %0,0,%3\n\

        bne-    1b"

        : "=&r" (old), "=m" (*p)

        : "r" (mask), "r" (p), "m" (*p)

        : "cc");

}

static __inline__ int test_and_set_bit(unsigned long nr, volatile void *addr)

{

        unsigned long old, t;

        unsigned long mask = 1UL << (nr & 0x3f);

        unsigned long *p = ((unsigned long *)addr) + (nr >> 6);

        __asm__ __volatile__(

        EIEIO_ON_SMP

"1:     ldarx   %0,0,%3         # test_and_set_bit\n\

        or      %1,%0,%2 \n\

        stdcx.  %1,0,%3 \n\

        bne-    1b"

        ISYNC_ON_SMP

        : "=&r" (old), "=&r" (t)

        : "r" (mask), "r" (p)

        : "cc", "memory");

        return (old & mask) != 0;

}

static __inline__ int test_and_clear_bit(unsigned long nr, volatile void *addr)

{

        unsigned long old, t;

        unsigned long mask = 1UL << (nr & 0x3f);

        unsigned long *p = ((unsigned long *)addr) + (nr >> 6);

        __asm__ __volatile__(

        EIEIO_ON_SMP

"1:     ldarx   %0,0,%3         # test_and_clear_bit\n\

        andc    %1,%0,%2\n\

        stdcx.  %1,0,%3\n\

        bne-    1b"

        ISYNC_ON_SMP

        : "=&r" (old), "=&r" (t)

        : "r" (mask), "r" (p)

        : "cc", "memory");

        return (old & mask) != 0;

}

static __inline__ int test_and_change_bit(unsigned long nr, volatile void *addr)

{

        unsigned long old, t;

        unsigned long mask = 1UL << (nr & 0x3f);

        unsigned long *p = ((unsigned long *)addr) + (nr >> 6);

        __asm__ __volatile__(

        EIEIO_ON_SMP

"1:     ldarx   %0,0,%3         # test_and_change_bit\n\

        xor     %1,%0,%2\n\

        stdcx.  %1,0,%3\n\

        bne-    1b"

        ISYNC_ON_SMP

        : "=&r" (old), "=&r" (t)

        : "r" (mask), "r" (p)

        : "cc", "memory");

        return (old & mask) != 0;

}

/*

 * non-atomic versions

 */

static __inline__ void __set_bit(unsigned long nr, volatile void *addr)

{

        unsigned long mask = 1UL << (nr & 0x3f);

        unsigned long *p = ((unsigned long *)addr) + (nr >> 6);

        *p |= mask;

}

static __inline__ void __clear_bit(unsigned long nr, volatile void *addr)

{

        unsigned long mask = 1UL << (nr & 0x3f);

        unsigned long *p = ((unsigned long *)addr) + (nr >> 6);

        *p &= ~mask;

}

static __inline__ void __change_bit(unsigned long nr, volatile void *addr)

{

        unsigned long mask = 1UL << (nr & 0x3f);

        unsigned long *p = ((unsigned long *)addr) + (nr >> 6);

        *p ^= mask;

}

static __inline__ int __test_and_set_bit(unsigned long nr, volatile void *addr)

{

        unsigned long mask = 1UL << (nr & 0x3f);

        unsigned long *p = ((unsigned long *)addr) + (nr >> 6);

        unsigned long old = *p;

        *p = old | mask;

        return (old & mask) != 0;

}

static __inline__ int __test_and_clear_bit(unsigned long nr, volatile void *addr)

{

        unsigned long mask = 1UL << (nr & 0x3f);

        unsigned long *p = ((unsigned long *)addr) + (nr >> 6);

        unsigned long old = *p;

        *p = old & ~mask;

        return (old & mask) != 0;

}

static __inline__ int __test_and_change_bit(unsigned long nr, volatile void *addr)

{

        unsigned long mask = 1UL << (nr & 0x3f);

        unsigned long *p = ((unsigned long *)addr) + (nr >> 6);

        unsigned long old = *p;

        *p = old ^ mask;

        return (old & mask) != 0;

}

/*

 * Return the zero-based bit position (from RIGHT TO LEFT, 63 -> 0) of the

 * most significant (left-most) 1-bit in a double word.

 */

static __inline__ int __ilog2(unsigned long x)

{

        int lz;

        asm ("cntlzd %0,%1" : "=r" (lz) : "r" (x));

        return 63 - lz;

}

/* Return the zero-based bit position

 *  from RIGHT TO LEFT  63 --> 0

 *   of the most significant (left-most) 1-bit in an 8-byte area.

 */

static __inline__ long cnt_trailing_zeros(unsigned long mask)

{

        long cnt;

        asm(

"       addi    %0,%1,-1        \n\

        andc    %0,%0,%1        \n\

        cntlzd  %0,%0           \n\

        subfic  %0,%0,64"

        : "=r" (cnt)

        : "r" (mask));

        return cnt;

}

/*

 * ffz = Find First Zero in word.

 * Determines the bit position of the least significant (rightmost) 0 bit

 * in the specified double word. The returned bit position will be zero-based,

 * starting from the right side (63 - 0).

 */

static __inline__ unsigned long ffz(unsigned long x)

{

        /* no zero exists anywhere in the 8 byte area. */

        if ((x = ~x) == 0)

                return 64;

        /*

         * Calculate the bit position of the least signficant '1' bit in x

         * (since x has been changed this will actually be the least signficant

         * '0' bit in * the original x).  Note: (x & -x) gives us a mask that

         * is the least significant * (RIGHT-most) 1-bit of the value in x.

         */

        return __ilog2(x & -x);

}

static __inline__ int __ffs(unsigned long x)

{

        return __ilog2(x & -x);

}

/*

 * 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).

 */

static __inline__ int ffs(int x)

{

        unsigned long i = (unsigned long)x;

        return __ilog2(i & -i) + 1;

}

/*

 * fls: find last (most-significant) bit set.

 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.

 */

#define fls(x) generic_fls(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)

extern unsigned long find_next_zero_bit(unsigned long* addr, unsigned long size, unsigned long offset);

#define find_first_zero_bit(addr, size) \

        find_next_zero_bit((addr), (size), 0)

extern unsigned long find_next_bit(unsigned long* addr, unsigned long size, unsigned long offset);

#define find_first_bit(addr, size) \

        find_next_bit((addr), (size), 0)

extern unsigned long find_next_zero_le_bit(unsigned long *addr, unsigned long size, unsigned long offset);

#define find_first_zero_le_bit(addr, size) \

        find_next_zero_le_bit((addr), (size), 0)

static __inline__ int test_le_bit(unsigned long nr, __const__ unsigned long * addr)

{

        __const__ unsigned char *ADDR = (__const__ unsigned char *) addr;

        return (ADDR[nr >> 3] >> (nr & 7)) & 1;

}

/*

 * non-atomic versions

 */

static __inline__ void __set_le_bit(unsigned long nr, unsigned long *addr)

{

        unsigned char *ADDR = (unsigned char *)addr;

        ADDR += nr >> 3;

        *ADDR |= 1 << (nr & 0x07);

}

static __inline__ void __clear_le_bit(unsigned long nr, unsigned long *addr)

{

        unsigned char *ADDR = (unsigned char *)addr;

        ADDR += nr >> 3;

        *ADDR &= ~(1 << (nr & 0x07));

}

static __inline__ int __test_and_set_le_bit(unsigned long nr, unsigned long *addr)

{

        int mask, retval;

        unsigned char *ADDR = (unsigned char *)addr;

        ADDR += nr >> 3;

        mask = 1 << (nr & 0x07);

        retval = (mask & *ADDR) != 0;

        *ADDR |= mask;

        return retval;

}

static __inline__ int __test_and_clear_le_bit(unsigned long nr, unsigned long *addr)

{

        int mask, retval;

        unsigned char *ADDR = (unsigned char *)addr;

        ADDR += nr >> 3;

        mask = 1 << (nr & 0x07);

        retval = (mask & *ADDR) != 0;

        *ADDR &= ~mask;

        return retval;

}

#define ext2_set_bit(nr,addr) \

        __test_and_set_le_bit((nr),(unsigned long*)addr)

#define ext2_clear_bit(nr, addr) \

        __test_and_clear_le_bit((nr),(unsigned long*)addr)

#define ext2_test_bit(nr, addr)      test_le_bit((nr),(unsigned long*)addr)

#define ext2_find_first_zero_bit(addr, size) \

        find_first_zero_le_bit((unsigned long*)addr, size)

#define ext2_find_next_zero_bit(addr, size, off) \

        find_next_zero_le_bit((unsigned long*)addr, size, off)

#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 /* _PPC64_BITOPS_H */