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linux/include/asm-xtensa/bitops.h
Chris Zankel 9a8fd55899 [PATCH] xtensa: Architecture support for Tensilica Xtensa Part 6 
The attached patches provides part 6 of an architecture implementation for the
Tensilica Xtensa CPU series.

Signed-off-by: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 00:05:22 -07:00

447 lines
10 KiB
C
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/*
* 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 - 2005 Tensilica Inc.
*/
#ifndef _XTENSA_BITOPS_H
#define _XTENSA_BITOPS_H
#ifdef __KERNEL__
#include <asm/processor.h>
#include <asm/byteorder.h>
#include <asm/system.h>
#ifdef CONFIG_SMP
# error SMP not supported on this architecture
#endif
static __inline__ void set_bit(int nr, volatile void * addr)
{
unsigned long mask = 1 << (nr & 0x1f);
unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
unsigned long flags;
local_irq_save(flags);
*a |= mask;
local_irq_restore(flags);
}
static __inline__ void __set_bit(int nr, volatile unsigned long * addr)
{
unsigned long mask = 1 << (nr & 0x1f);
unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
*a |= mask;
}
static __inline__ void clear_bit(int nr, volatile void * addr)
{
unsigned long mask = 1 << (nr & 0x1f);
unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
unsigned long flags;
local_irq_save(flags);
*a &= ~mask;
local_irq_restore(flags);
}
static __inline__ void __clear_bit(int nr, volatile unsigned long *addr)
{
unsigned long mask = 1 << (nr & 0x1f);
unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
*a &= ~mask;
}
/*
* clear_bit() doesn't provide any barrier for the compiler.
*/
#define smp_mb__before_clear_bit() barrier()
#define smp_mb__after_clear_bit() barrier()
static __inline__ void change_bit(int nr, volatile void * addr)
{
unsigned long mask = 1 << (nr & 0x1f);
unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
unsigned long flags;
local_irq_save(flags);
*a ^= mask;
local_irq_restore(flags);
}
static __inline__ void __change_bit(int nr, volatile void * addr)
{
unsigned long mask = 1 << (nr & 0x1f);
unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
*a ^= mask;
}
static __inline__ int test_and_set_bit(int nr, volatile void * addr)
{
unsigned long retval;
unsigned long mask = 1 << (nr & 0x1f);
unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
unsigned long flags;
local_irq_save(flags);
retval = (mask & *a) != 0;
*a |= mask;
local_irq_restore(flags);
return retval;
}
static __inline__ int __test_and_set_bit(int nr, volatile void * addr)
{
unsigned long retval;
unsigned long mask = 1 << (nr & 0x1f);
unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
retval = (mask & *a) != 0;
*a |= mask;
return retval;
}
static __inline__ int test_and_clear_bit(int nr, volatile void * addr)
{
unsigned long retval;
unsigned long mask = 1 << (nr & 0x1f);
unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
unsigned long flags;
local_irq_save(flags);
retval = (mask & *a) != 0;
*a &= ~mask;
local_irq_restore(flags);
return retval;
}
static __inline__ int __test_and_clear_bit(int nr, volatile void * addr)
{
unsigned long mask = 1 << (nr & 0x1f);
unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
unsigned long old = *a;
*a = old & ~mask;
return (old & mask) != 0;
}
static __inline__ int test_and_change_bit(int nr, volatile void * addr)
{
unsigned long retval;
unsigned long mask = 1 << (nr & 0x1f);
unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
unsigned long flags;
local_irq_save(flags);
retval = (mask & *a) != 0;
*a ^= mask;
local_irq_restore(flags);
return retval;
}
/*
* non-atomic version; can be reordered
*/
static __inline__ int __test_and_change_bit(int nr, volatile void *addr)
{
unsigned long mask = 1 << (nr & 0x1f);
unsigned long *a = ((unsigned long *)addr) + (nr >> 5);
unsigned long old = *a;
*a = old ^ mask;
return (old & mask) != 0;
}
static __inline__ int test_bit(int nr, const volatile void *addr)
{
return 1UL & (((const volatile unsigned int *)addr)[nr>>5] >> (nr&31));
}
#if XCHAL_HAVE_NSAU
static __inline__ int __cntlz (unsigned long x)
{
int lz;
asm ("nsau %0, %1" : "=r" (lz) : "r" (x));
return 31 - lz;
}
#else
static __inline__ int __cntlz (unsigned long x)
{
unsigned long sum, x1, x2, x4, x8, x16;
x1 = x & 0xAAAAAAAA;
x2 = x & 0xCCCCCCCC;
x4 = x & 0xF0F0F0F0;
x8 = x & 0xFF00FF00;
x16 = x & 0xFFFF0000;
sum = x2 ? 2 : 0;
sum += (x16 != 0) * 16;
sum += (x8 != 0) * 8;
sum += (x4 != 0) * 4;
sum += (x1 != 0);
return sum;
}
#endif
/*
* 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)
{
if ((x = ~x) == 0)
return 32;
return __cntlz(x & -x);
}
/*
* __ffs: Find first bit set in word. Return 0 for bit 0
*/
static __inline__ int __ffs(unsigned long x)
{
return __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 __cntlz(x & -x) + 1;
}
/*
* 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 __cntlz(x);
}
static __inline__ int
find_next_bit(const unsigned long *addr, int size, int offset)
{
const unsigned long *p = addr + (offset >> 5);
unsigned long result = offset & ~31UL;
unsigned long tmp;
if (offset >= size)
return size;
size -= result;
offset &= 31UL;
if (offset) {
tmp = *p++;
tmp &= ~0UL << offset;
if (size < 32)
goto found_first;
if (tmp)
goto found_middle;
size -= 32;
result += 32;
}
while (size >= 32) {
if ((tmp = *p++) != 0)
goto found_middle;
result += 32;
size -= 32;
}
if (!size)
return result;
tmp = *p;
found_first:
tmp &= ~0UL >> (32 - size);
if (tmp == 0UL) /* Are any bits set? */
return result + size; /* Nope. */
found_middle:
return result + __ffs(tmp);
}
/**
* 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)
static __inline__ int
find_next_zero_bit(const unsigned long *addr, int size, int offset)
{
const unsigned long *p = addr + (offset >> 5);
unsigned long result = offset & ~31UL;
unsigned long tmp;
if (offset >= size)
return size;
size -= result;
offset &= 31UL;
if (offset) {
tmp = *p++;
tmp |= ~0UL >> (32-offset);
if (size < 32)
goto found_first;
if (~tmp)
goto found_middle;
size -= 32;
result += 32;
}
while (size & ~31UL) {
if (~(tmp = *p++))
goto found_middle;
result += 32;
size -= 32;
}
if (!size)
return result;
tmp = *p;
found_first:
tmp |= ~0UL << size;
found_middle:
return result + ffz(tmp);
}
#define find_first_zero_bit(addr, size) \
find_next_zero_bit((addr), (size), 0)
#ifdef __XTENSA_EL__
# define ext2_set_bit(nr,addr) __test_and_set_bit((nr), (addr))
# define ext2_set_bit_atomic(lock,nr,addr) test_and_set_bit((nr),(addr))
# define ext2_clear_bit(nr,addr) __test_and_clear_bit((nr), (addr))
# define ext2_clear_bit_atomic(lock,nr,addr) test_and_clear_bit((nr),(addr))
# define ext2_test_bit(nr,addr) test_bit((nr), (addr))
# define ext2_find_first_zero_bit(addr, size) find_first_zero_bit((addr),(size))
# define ext2_find_next_zero_bit(addr, size, offset) \
find_next_zero_bit((addr), (size), (offset))
#elif defined(__XTENSA_EB__)
# define ext2_set_bit(nr,addr) __test_and_set_bit((nr) ^ 0x18, (addr))
# define ext2_set_bit_atomic(lock,nr,addr) test_and_set_bit((nr) ^ 0x18, (addr))
# define ext2_clear_bit(nr,addr) __test_and_clear_bit((nr) ^ 18, (addr))
# define ext2_clear_bit_atomic(lock,nr,addr) test_and_clear_bit((nr)^0x18,(addr))
# define ext2_test_bit(nr,addr) test_bit((nr) ^ 0x18, (addr))
# define ext2_find_first_zero_bit(addr, size) \
ext2_find_next_zero_bit((addr), (size), 0)
static __inline__ unsigned long ext2_find_next_zero_bit(void *addr, unsigned long size, unsigned long offset)
{
unsigned long *p = ((unsigned long *) addr) + (offset >> 5);
unsigned long result = offset & ~31UL;
unsigned long tmp;
if (offset >= size)
return size;
size -= result;
offset &= 31UL;
if(offset) {
/* We hold the little endian value in tmp, but then the
* shift is illegal. So we could keep a big endian value
* in tmp, like this:
*
* tmp = __swab32(*(p++));
* tmp |= ~0UL >> (32-offset);
*
* but this would decrease preformance, so we change the
* shift:
*/
tmp = *(p++);
tmp |= __swab32(~0UL >> (32-offset));
if(size < 32)
goto found_first;
if(~tmp)
goto found_middle;
size -= 32;
result += 32;
}
while(size & ~31UL) {
if(~(tmp = *(p++)))
goto found_middle;
result += 32;
size -= 32;
}
if(!size)
return result;
tmp = *p;
found_first:
/* tmp is little endian, so we would have to swab the shift,
* see above. But then we have to swab tmp below for ffz, so
* we might as well do this here.
*/
return result + ffz(__swab32(tmp) | (~0UL << size));
found_middle:
return result + ffz(__swab32(tmp));
}
#else
# error processor byte order undefined!
#endif
#define hweight32(x) generic_hweight32(x)
#define hweight16(x) generic_hweight16(x)
#define hweight8(x) generic_hweight8(x)
/*
* Find the first bit set in a 140-bit bitmap.
* The first 100 bits are unlikely to be set.
*/
static inline int sched_find_first_bit(const unsigned long *b)
{
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;
}
/* Bitmap functions for the minix filesystem. */
#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 /* _XTENSA_BITOPS_H */
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