/*
* 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>
/*
* 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)
/* Macro for generating the ***_bits() functions */
#define DEFINE_BITOP(fn, op, prefix, postfix) \
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\n" \
stringify_in_c(op) "%0,%0,%2\n" \
PPC405_ERR77(0,%3) \
PPC_STLCX "%0,0,%3\n" \
"bne- 1b\n" \
postfix \
: "=&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, LWSYNC_ON_SMP, "")
DEFINE_BITOP(change_bits, xor, "", "")
static __inline__ void set_bit(int nr, volatile unsigned long *addr)
{
set_bits(BITOP_MASK(nr), addr + BITOP_WORD(nr));
}
static __inline__ void clear_bit(int nr, volatile unsigned long *addr)
{
clear_bits(BITOP_MASK(nr), addr + BITOP_WORD(nr));
}
static __inline__ void clear_bit_unlock(int nr, volatile unsigned long *addr)
{
clear_bits_unlock(BITOP_MASK(nr), addr + BITOP_WORD(nr));
}
static __inline__ void change_bit(int nr, volatile unsigned long *addr)
{
change_bits(BITOP_MASK(nr), addr + BITOP_WORD(nr));
}
/* Like DEFINE_BITOP(), with changes to the arguments to 'op' and the output
* operands. */
#define DEFINE_TESTOP(fn, op, prefix, postfix) \
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\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, LWSYNC_ON_SMP, ISYNC_ON_SMP)
DEFINE_TESTOP(test_and_set_bits_lock, or, "", ISYNC_ON_SMP)
DEFINE_TESTOP(test_and_clear_bits, andc, LWSYNC_ON_SMP, ISYNC_ON_SMP)
DEFINE_TESTOP(test_and_change_bits, xor, LWSYNC_ON_SMP, ISYNC_ON_SMP)
static __inline__ int test_and_set_bit(unsigned long nr,
volatile unsigned long *addr)
{
return test_and_set_bits(BITOP_MASK(nr), addr + BITOP_WORD(nr)) != 0;
}
static __inline__ int test_and_set_bit_lock(unsigned long nr,
volatile unsigned long *addr)
{
return test_and_set_bits_lock(BITOP_MASK(nr),
addr + BITOP_WORD(nr)) != 0;
}
static __inline__ int test_and_clear_bit(unsigned long nr,
volatile unsigned long *addr)
{
return test_and_clear_bits(BITOP_MASK(nr), addr + BITOP_WORD(nr)) != 0;
}
static __inline__ int test_and_change_bit(unsigned long nr,
volatile unsigned long *addr)
{
return test_and_change_bits(BITOP_MASK(nr), addr + BITOP_WORD(nr)) != 0;
}
#include <asm-generic/bitops/non-atomic.h>
static __inline__ void __clear_bit_unlock(int nr, volatile unsigned long *addr)
{
__asm__ __volatile__(LWSYNC_ON_SMP "" ::: "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 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;
}
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__ */
#include <asm-generic/bitops/hweight.h>
#include <asm-generic/bitops/find.h>
/* 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) generic_find_next_zero_le_bit((addr), (size), 0)
unsigned long generic_find_next_zero_le_bit(const unsigned long *addr,
unsigned long size, unsigned long offset);
unsigned long generic_find_next_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) \
generic_find_next_zero_le_bit((unsigned long*)addr, size, off)
#define ext2_find_next_bit(addr, size, off) \
generic_find_next_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)
#include <asm-generic/bitops/sched.h>
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_BITOPS_H */
