/*
* PowerPC atomic bit operations.
*
* Merged version by David Gibson <david@gibson.dropbear.id.au>.
* Based on ppc64 versions by: Dave Engebretsen, Todd Inglett, Don
* Reed, Pat McCarthy, Peter Bergner, Anton Blanchard. They
* originally took it from the ppc32 code.
*
* Within a word, bits are numbered LSB first. Lot's of places make
* this assumption by directly testing bits with (val & (1<<nr)).
* This can cause confusion for large (> 1 word) bitmaps on a
* big-endian system because, unlike little endian, the number of each
* bit depends on the word size.
*
* The bitop functions are defined to work on unsigned longs, so for a
* ppc64 system the bits end up numbered:
* |63..............0|127............64|191...........128|255...........196|
* and on ppc32:
* |31.....0|63....31|95....64|127...96|159..128|191..160|223..192|255..224|
*
* There are a few little-endian macros used mostly for filesystem
* bitmaps, these work on similar bit arrays layouts, but
* byte-oriented:
* |7...0|15...8|23...16|31...24|39...32|47...40|55...48|63...56|
*
* The main difference is that bit 3-5 (64b) or 3-4 (32b) in the bit
* number field needs to be reversed compared to the big-endian bit
* fields. This can be achieved by XOR with 0x38 (64b) or 0x18 (32b).
*
* 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 _ASM_POWERPC_BITOPS_H
#define _ASM_POWERPC_BITOPS_H
#ifdef __KERNEL__
#include <linux/compiler.h>
#include <asm/atomic.h>
#include <asm/synch.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()
#define BITOP_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
#define BITOP_WORD(nr) ((nr) / BITS_PER_LONG)
#define BITOP_LE_SWIZZLE ((BITS_PER_LONG-1) & ~0x7)
#ifdef CONFIG_PPC64
#define LARXL "ldarx"
#define STCXL "stdcx."
#define CNTLZL "cntlzd"
#else
#define LARXL "lwarx"
#define STCXL "stwcx."
#define CNTLZL "cntlzw"
#endif
static __inline__ void set_bit(int nr, volatile unsigned long *addr)
{
unsigned long old;
unsigned long mask = BITOP_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
__asm__ __volatile__(
"1:" LARXL " %0,0,%3 # set_bit\n"
"or %0,%0,%2\n"
PPC405_ERR77(0,%3)
STCXL " %0,0,%3\n"
"bne- 1b"
: "=&r"(old), "=m"(*p)
: "r"(mask), "r"(p), "m"(*p)
: "cc" );
}
static __inline__ void clear_bit(int nr, volatile unsigned long *addr)
{
unsigned long old;
unsigned long mask = BITOP_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
__asm__ __volatile__(
"1:" LARXL " %0,0,%3 # set_bit\n"
"andc %0,%0,%2\n"
PPC405_ERR77(0,%3)
STCXL " %0,0,%3\n"
"bne- 1b"
: "=&r"(old), "=m"(*p)
: "r"(mask), "r"(p), "m"(*p)
: "cc" );
}
static __inline__ void change_bit(int nr, volatile unsigned long *addr)
{
unsigned long old;
unsigned long mask = BITOP_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
__asm__ __volatile__(
"1:" LARXL " %0,0,%3 # set_bit\n"
"xor %0,%0,%2\n"
PPC405_ERR77(0,%3)
STCXL " %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 unsigned long *addr)
{
unsigned long old, t;
unsigned long mask = BITOP_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
__asm__ __volatile__(
EIEIO_ON_SMP
"1:" LARXL " %0,0,%3 # test_and_set_bit\n"
"or %1,%0,%2 \n"
PPC405_ERR77(0,%3)
STCXL " %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 unsigned long *addr)
{
unsigned long old, t;
unsigned long mask = BITOP_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
__asm__ __volatile__(
EIEIO_ON_SMP
"1:" LARXL " %0,0,%3 # test_and_clear_bit\n"
"andc %1,%0,%2 \n"
PPC405_ERR77(0,%3)
STCXL " %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 unsigned long *addr)
{
unsigned long old, t;
unsigned long mask = BITOP_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
__asm__ __volatile__(
EIEIO_ON_SMP
"1:" LARXL " %0,0,%3 # test_and_change_bit\n"
"xor %1,%0,%2 \n"
PPC405_ERR77(0,%3)
STCXL " %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__ void set_bits(unsigned long mask, unsigned long *addr)
{
unsigned long old;
__asm__ __volatile__(
"1:" LARXL " %0,0,%3 # set_bit\n"
"or %0,%0,%2\n"
STCXL " %0,0,%3\n"
"bne- 1b"
: "=&r" (old), "=m" (*addr)
: "r" (mask), "r" (addr), "m" (*addr)
: "cc");
}
/* Non-atomic versions */
static __inline__ int test_bit(unsigned long nr,
__const__ volatile unsigned long *addr)
{
return 1UL & (addr[BITOP_WORD(nr)] >> (nr & (BITS_PER_LONG-1)));
}
static __inline__ void __set_bit(unsigned long nr,
volatile unsigned long *addr)
{
unsigned long mask = BITOP_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
*p |= mask;
}
static __inline__ void __clear_bit(unsigned long nr,
volatile unsigned long *addr)
{
unsigned long mask = BITOP_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
*p &= ~mask;
}
static __inline__ void __change_bit(unsigned long nr,
volatile unsigned long *addr)
{
unsigned long mask = BITOP_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
*p ^= mask;
}
static __inline__ int __test_and_set_bit(unsigned long nr,
volatile unsigned long *addr)
{
unsigned long mask = BITOP_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
unsigned long old = *p;
*p = old | mask;
return (old & mask) != 0;
}
static __inline__ int __test_and_clear_bit(unsigned long nr,
volatile unsigned long *addr)
{
unsigned long mask = BITOP_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
unsigned long old = *p;
*p = old & ~mask;
return (old & mask) != 0;
}
static __inline__ int __test_and_change_bit(unsigned long nr,
volatile unsigned long *addr)
{
unsigned long mask = BITOP_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
unsigned long old = *p;
*p = old ^ mask;
return (old & mask) != 0;
}
/*
* Return the zero-based bit position (LE, not IBM bit numbering) of
* the most significant 1-bit in a double word.
*/
static __inline__ int __ilog2(unsigned long x)
{
int lz;
asm (CNTLZL " %0,%1" : "=r" (lz) : "r" (x));
return BITS_PER_LONG - 1 - lz;
}
/*
* Determines the bit position of the least significant 0 bit in the
* specified double word. The returned bit position will be
* zero-based, starting from the right side (63/31 - 0).
*/
static __inline__ unsigned long ffz(unsigned long x)
{
/* no zero exists anywhere in the 8 byte area. */
if ((x = ~x) == 0)
return BITS_PER_LONG;
/*
* 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.
*/
static __inline__ int fls(unsigned int x)
{
int lz;
asm ("cntlzw %0,%1" : "=r" (lz) : "r" (x));
return 32 - lz;
}
/*
* hweightN: returns the hamming weight (i.e. the number
* of bits set) of a N-bit word
*/
#define hweight64(x) generic_hweight64(x)
#define hweight32(x) generic_hweight32(x)
#define hweight16(x) generic_hweight16(x)
#define hweight8(x) generic_hweight8(x)
#define find_first_zero_bit(addr, size) find_next_zero_bit((addr), (size), 0)
unsigned long find_next_zero_bit(const unsigned long *addr,
unsigned long size, unsigned long offset);
/**
* find_first_bit - find the first set bit in a memory region
* @addr: The address to start the search at
* @size: The maximum size to search
*
* Returns the bit-number of the first set bit, not the number of the byte
* containing a bit.
*/
#define find_first_bit(addr, size) find_next_bit((addr), (size), 0)
unsigned long find_next_bit(const unsigned long *addr,
unsigned long size, unsigned long offset);
/* Little-endian versions */
static __inline__ int test_le_bit(unsigned long nr,
__const__ unsigned long *addr)
{
__const__ unsigned char *tmp = (__const__ unsigned char *) addr;
return (tmp[nr >> 3] >> (nr & 7)) & 1;
}
#define __set_le_bit(nr, addr) \
__set_bit((nr) ^ BITOP_LE_SWIZZLE, (addr))
#define __clear_le_bit(nr, addr) \
__clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr))
#define test_and_set_le_bit(nr, addr) \
test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, (addr))
#define test_and_clear_le_bit(nr, addr) \
test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr))
#define __test_and_set_le_bit(nr, addr) \
__test_and_set_bit((nr) ^ BITOP_LE_SWIZZLE, (addr))
#define __test_and_clear_le_bit(nr, addr) \
__test_and_clear_bit((nr) ^ BITOP_LE_SWIZZLE, (addr))
#define find_first_zero_le_bit(addr, size) find_next_zero_le_bit((addr), (size), 0)
unsigned long find_next_zero_le_bit(const unsigned long *addr,
unsigned long size, unsigned long offset);
/* Bitmap functions for the ext2 filesystem */
#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_set_bit_atomic(lock, nr, addr) \
test_and_set_le_bit((nr), (unsigned long*)addr)
#define ext2_clear_bit_atomic(lock, 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)
/* Bitmap functions for the minix filesystem. */
#define minix_test_and_set_bit(nr,addr) \
__test_and_set_le_bit(nr, (unsigned long *)addr)
#define minix_set_bit(nr,addr) \
__set_le_bit(nr, (unsigned long *)addr)
#define minix_test_and_clear_bit(nr,addr) \
__test_and_clear_le_bit(nr, (unsigned long *)addr)
#define minix_test_bit(nr,addr) \
test_le_bit(nr, (unsigned long *)addr)
#define minix_find_first_zero_bit(addr,size) \
find_first_zero_le_bit((unsigned long *)addr, size)
/*
* Every architecture must define this function. It's the fastest
* way of searching a 140-bit bitmap where the first 100 bits are
* unlikely to be set. It's guaranteed that at least one of the 140
* bits is cleared.
*/
static inline int sched_find_first_bit(const unsigned long *b)
{
#ifdef CONFIG_PPC64
if (unlikely(b[0]))
return __ffs(b[0]);
if (unlikely(b[1]))
return __ffs(b[1]) + 64;
return __ffs(b[2]) + 128;
#else
if (unlikely(b[0]))
return __ffs(b[0]);
if (unlikely(b[1]))
return __ffs(b[1]) + 32;
if (unlikely(b[2]))
return __ffs(b[2]) + 64;
if (b[3])
return __ffs(b[3]) + 96;
return __ffs(b[4]) + 128;
#endif
}
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_BITOPS_H */
