/*
* 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__
#ifndef _LINUX_BITOPS_H
#error only <linux/bitops.h> can be included directly
#endif
#include <linux/compiler.h>
#include <asm/asm-compat.h>
#include <asm/synch.h>
/* PPC bit number conversion */
#define PPC_BITLSHIFT(be) (BITS_PER_LONG - 1 - (be))
#define PPC_BIT(bit) (1UL << PPC_BITLSHIFT(bit))
#define PPC_BITMASK(bs, be) ((PPC_BIT(bs) - PPC_BIT(be)) | PPC_BIT(bs))
#include <asm/barrier.h>
/* Macro for generating the ***_bits() functions */
#define DEFINE_BITOP(fn, op, prefix) \
static __inline__ void fn(unsigned long mask, \
volatile unsigned long *_p) \
{ \
unsigned long old; \
unsigned long *p = (unsigned long *)_p; \
__asm__ __volatile__ ( \
prefix \
"1:" PPC_LLARX(%0,0,%3,0) "\n" \
stringify_in_c(op) "%0,%0,%2\n" \
PPC405_ERR77(0,%3) \
PPC_STLCX "%0,0,%3\n" \
"bne- 1b\n" \
: "=&r" (old), "+m" (*p) \
: "r" (mask), "r" (p) \
: "cc", "memory"); \
}
DEFINE_BITOP(set_bits, or, "")
DEFINE_BITOP(clear_bits, andc, "")
DEFINE_BITOP(clear_bits_unlock, andc, PPC_RELEASE_BARRIER)
DEFINE_BITOP(change_bits, xor, "")
static __inline__ void set_bit(int nr, volatile unsigned long *addr)
{
set_bits(BIT_MASK(nr), addr + BIT_WORD(nr));
}
static __inline__ void clear_bit(int nr, volatile unsigned long *addr)
{
clear_bits(BIT_MASK(nr), addr + BIT_WORD(nr));
}
static __inline__ void clear_bit_unlock(int nr, volatile unsigned long *addr)
{
clear_bits_unlock(BIT_MASK(nr), addr + BIT_WORD(nr));
}
static __inline__ void change_bit(int nr, volatile unsigned long *addr)
{
change_bits(BIT_MASK(nr), addr + BIT_WORD(nr));
}
/* Like DEFINE_BITOP(), with changes to the arguments to 'op' and the output
* operands. */
#define DEFINE_TESTOP(fn, op, prefix, postfix, eh) \
static __inline__ unsigned long fn( \
unsigned long mask, \
volatile unsigned long *_p) \
{ \
unsigned long old, t; \
unsigned long *p = (unsigned long *)_p; \
__asm__ __volatile__ ( \
prefix \
"1:" PPC_LLARX(%0,0,%3,eh) "\n" \
stringify_in_c(op) "%1,%0,%2\n" \
PPC405_ERR77(0,%3) \
PPC_STLCX "%1,0,%3\n" \
"bne- 1b\n" \
postfix \
: "=&r" (old), "=&r" (t) \
: "r" (mask), "r" (p) \
: "cc", "memory"); \
return (old & mask); \
}
DEFINE_TESTOP(test_and_set_bits, or, PPC_ATOMIC_ENTRY_BARRIER,
PPC_ATOMIC_EXIT_BARRIER, 0)
DEFINE_TESTOP(test_and_set_bits_lock, or, "",
PPC_ACQUIRE_BARRIER, 1)
DEFINE_TESTOP(test_and_clear_bits, andc, PPC_ATOMIC_ENTRY_BARRIER,
PPC_ATOMIC_EXIT_BARRIER, 0)
DEFINE_TESTOP(test_and_change_bits, xor, PPC_ATOMIC_ENTRY_BARRIER,
PPC_ATOMIC_EXIT_BARRIER, 0)
static __inline__ int test_and_set_bit(unsigned long nr,
volatile unsigned long *addr)
{
return test_and_set_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0;
}
static __inline__ int test_and_set_bit_lock(unsigned long nr,
volatile unsigned long *addr)
{
return test_and_set_bits_lock(BIT_MASK(nr),
addr + BIT_WORD(nr)) != 0;
}
static __inline__ int test_and_clear_bit(unsigned long nr,
volatile unsigned long *addr)
{
return test_and_clear_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0;
}
static __inline__ int test_and_change_bit(unsigned long nr,
volatile unsigned long *addr)
{
return test_and_change_bits(BIT_MASK(nr), addr + BIT_WORD(nr)) != 0;
}
#include <asm-generic/bitops/non-atomic.h>
static __inline__ void __clear_bit_unlock(int nr, volatile unsigned long *addr)
{
__asm__ __volatile__(PPC_RELEASE_BARRIER "" ::: "memory");
__clear_bit(nr, addr);
}
/*
* Return the zero-based bit position (LE, not IBM bit numbering) of
* the most significant 1-bit in a double word.
*/
static __inline__ __attribute__((const))
int __ilog2(unsigned long x)
{
int lz;
asm (PPC_CNTLZL "%0,%1" : "=r" (lz) : "r" (x));
return BITS_PER_LONG - 1 - lz;
}
static inline __attribute__((const))
int __ilog2_u32(u32 n)
{
int bit;
asm ("cntlzw %0,%1" : "=r" (bit) : "r" (n));
return 31 - bit;
}
#ifdef __powerpc64__
static inline __attribute__((const))
int __ilog2_u64(u64 n)
{
int bit;
asm ("cntlzd %0,%1" : "=r" (bit) : "r" (n));
return 63 - bit;
}
#endif
/*
* 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 significant '1' bit in x
* (since x has been changed this will actually be the least significant
* '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;
}
static __inline__ unsigned long __fls(unsigned long x)
{
return __ilog2(x);
}
/*
* 64-bit can do this using one cntlzd (count leading zeroes doubleword)
* instruction; for 32-bit we use the generic version, which does two
* 32-bit fls calls.
*/
#ifdef __powerpc64__
static __inline__ int fls64(__u64 x)
{
int lz;
asm ("cntlzd %0,%1" : "=r" (lz) : "r" (x));
return 64 - lz;
}
#else
#include <asm-generic/bitops/fls64.h>
#endif /* __powerpc64__ */
#ifdef CONFIG_PPC64
unsigned int __arch_hweight8(unsigned int w);
unsigned int __arch_hweight16(unsigned int w);
unsigned int __arch_hweight32(unsigned int w);
unsigned long __arch_hweight64(__u64 w);
#include <asm-generic/bitops/const_hweight.h>
#else
#include <asm-generic/bitops/hweight.h>
#endif
#include <asm-generic/bitops/find.h>
/* Little-endian versions */
#include <asm-generic/bitops/le.h>
/* Bitmap functions for the ext2 filesystem */
#include <asm-generic/bitops/ext2-atomic-setbit.h>
#include <asm-generic/bitops/sched.h>
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_BITOPS_H */