Viewing file:  bitops.h (5.21 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/*
* include/asm-xtensa/bitops.h
*
* Atomic operations that C can't guarantee us.Useful for resource counting etc.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2001 - 2007 Tensilica Inc.
*/
#ifndef _XTENSA_BITOPS_H
#define _XTENSA_BITOPS_H
#ifdef __KERNEL__
#ifndef _LINUX_BITOPS_H
#error only <linux/bitops.h> can be included directly
#endif
#include <asm/processor.h>
#include <asm/byteorder.h>
#ifdef CONFIG_SMP
# error SMP not supported on this architecture
#endif
#define smp_mb__before_clear_bit() barrier()
#define smp_mb__after_clear_bit() barrier()
#include <asm-generic/bitops/non-atomic.h>
#if XCHAL_HAVE_NSA
static inline unsigned long __cntlz (unsigned long x)
{
int lz;
asm ("nsau %0, %1" : "=r" (lz) : "r" (x));
return lz;
}
/*
* ffz: Find first zero in word. Undefined if no zero exists.
* bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
*/
static inline int ffz(unsigned long x)
{
return 31 - __cntlz(~x & -~x);
}
/*
* __ffs: Find first bit set in word. Return 0 for bit 0
*/
static inline int __ffs(unsigned long x)
{
return 31 - __cntlz(x & -x);
}
/*
* ffs: Find first bit set in word. 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(unsigned long x)
{
return 32 - __cntlz(x & -x);
}
/*
* fls: Find last (most-significant) bit set in word.
* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
*/
static inline int fls (unsigned int x)
{
return 32 - __cntlz(x);
}
/**
* __fls - find last (most-significant) set bit in a long word
* @word: the word to search
*
* Undefined if no set bit exists, so code should check against 0 first.
*/
static inline unsigned long __fls(unsigned long word)
{
return 31 - __cntlz(word);
}
#else
/* Use the generic implementation if we don't have the nsa/nsau instructions. */
# include <asm-generic/bitops/ffs.h>
# include <asm-generic/bitops/__ffs.h>
# include <asm-generic/bitops/ffz.h>
# include <asm-generic/bitops/fls.h>
# include <asm-generic/bitops/__fls.h>
#endif
#include <asm-generic/bitops/fls64.h>
#if XCHAL_HAVE_S32C1I
static inline void set_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long tmp, value;
unsigned long mask = 1UL << (bit & 31);
p += bit >> 5;
__asm__ __volatile__(
"1: l32i %1, %3, 0\n"
" wsr %1, scompare1\n"
" or %0, %1, %2\n"
" s32c1i %0, %3, 0\n"
" bne %0, %1, 1b\n"
: "=&a" (tmp), "=&a" (value)
: "a" (mask), "a" (p)
: "memory");
}
static inline void clear_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long tmp, value;
unsigned long mask = 1UL << (bit & 31);
p += bit >> 5;
__asm__ __volatile__(
"1: l32i %1, %3, 0\n"
" wsr %1, scompare1\n"
" and %0, %1, %2\n"
" s32c1i %0, %3, 0\n"
" bne %0, %1, 1b\n"
: "=&a" (tmp), "=&a" (value)
: "a" (~mask), "a" (p)
: "memory");
}
static inline void change_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long tmp, value;
unsigned long mask = 1UL << (bit & 31);
p += bit >> 5;
__asm__ __volatile__(
"1: l32i %1, %3, 0\n"
" wsr %1, scompare1\n"
" xor %0, %1, %2\n"
" s32c1i %0, %3, 0\n"
" bne %0, %1, 1b\n"
: "=&a" (tmp), "=&a" (value)
: "a" (mask), "a" (p)
: "memory");
}
static inline int
test_and_set_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long tmp, value;
unsigned long mask = 1UL << (bit & 31);
p += bit >> 5;
__asm__ __volatile__(
"1: l32i %1, %3, 0\n"
" wsr %1, scompare1\n"
" or %0, %1, %2\n"
" s32c1i %0, %3, 0\n"
" bne %0, %1, 1b\n"
: "=&a" (tmp), "=&a" (value)
: "a" (mask), "a" (p)
: "memory");
return tmp & mask;
}
static inline int
test_and_clear_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long tmp, value;
unsigned long mask = 1UL << (bit & 31);
p += bit >> 5;
__asm__ __volatile__(
"1: l32i %1, %3, 0\n"
" wsr %1, scompare1\n"
" and %0, %1, %2\n"
" s32c1i %0, %3, 0\n"
" bne %0, %1, 1b\n"
: "=&a" (tmp), "=&a" (value)
: "a" (~mask), "a" (p)
: "memory");
return tmp & mask;
}
static inline int
test_and_change_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long tmp, value;
unsigned long mask = 1UL << (bit & 31);
p += bit >> 5;
__asm__ __volatile__(
"1: l32i %1, %3, 0\n"
" wsr %1, scompare1\n"
" xor %0, %1, %2\n"
" s32c1i %0, %3, 0\n"
" bne %0, %1, 1b\n"
: "=&a" (tmp), "=&a" (value)
: "a" (mask), "a" (p)
: "memory");
return tmp & mask;
}
#else
#include <asm-generic/bitops/atomic.h>
#endif /* XCHAL_HAVE_S32C1I */
#include <asm-generic/bitops/find.h>
#include <asm-generic/bitops/le.h>
#include <asm-generic/bitops/ext2-atomic-setbit.h>
#include <asm-generic/bitops/hweight.h>
#include <asm-generic/bitops/lock.h>
#include <asm-generic/bitops/sched.h>
#endif /* __KERNEL__ */
#endif /* _XTENSA_BITOPS_H */
|