mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-24 11:29:10 +00:00
256 lines
6.2 KiB
C
256 lines
6.2 KiB
C
/* $FreeBSD$ */
|
|
#ifndef _ALPHA_BITOPS_H
|
|
#define _ALPHA_BITOPS_H
|
|
|
|
/*
|
|
* Copyright 1994, Linus Torvalds.
|
|
*/
|
|
|
|
/*
|
|
* These have to be done with inline assembly: that way the bit-setting
|
|
* is guaranteed to be atomic. All bit operations return 0 if the bit
|
|
* was cleared before the operation and != 0 if it was not.
|
|
*
|
|
* To get proper branch prediction for the main line, we must branch
|
|
* forward to code at the end of this object's .text section, then
|
|
* branch back to restart the operation.
|
|
*
|
|
* bit 0 is the LSB of addr; bit 64 is the LSB of (addr+1).
|
|
*/
|
|
static __inline unsigned int set_bit(unsigned long, volatile void *);
|
|
static __inline unsigned int clear_bit(unsigned long, volatile void *);
|
|
static __inline unsigned int change_bit(unsigned long, volatile void *);
|
|
static __inline unsigned int test_bit(int, volatile void *);
|
|
static __inline unsigned long ffz_b(unsigned long x);
|
|
static __inline unsigned long ffz(unsigned long);
|
|
/* static __inline int ffs(int); */
|
|
static __inline void * memscan(void *, int, size_t);
|
|
#ifdef __alpha_cix__
|
|
static __inline unsigned long hweight64(unsigned long);
|
|
#endif
|
|
static __inline unsigned long
|
|
find_next_zero_bit(void *, unsigned long, unsigned long);
|
|
|
|
static __inline unsigned int set_bit(unsigned long nr, volatile void * addr)
|
|
{
|
|
unsigned long oldbit;
|
|
unsigned long temp;
|
|
volatile unsigned int *m = ((volatile unsigned int *) addr) + (nr >> 5);
|
|
|
|
__asm__ __volatile__(
|
|
"1: ldl_l %0,%1\n"
|
|
" and %0,%3,%2\n"
|
|
" bne %2,2f\n"
|
|
" xor %0,%3,%0\n"
|
|
" stl_c %0,%1\n"
|
|
" beq %0,3f\n"
|
|
"2:\n"
|
|
".section .text2,\"ax\"\n"
|
|
"3: br 1b\n"
|
|
".previous"
|
|
:"=&r" (temp), "=m" (*m), "=&r" (oldbit)
|
|
:"Ir" (1UL << (nr & 31)), "m" (*m));
|
|
return oldbit;
|
|
}
|
|
|
|
static __inline unsigned int clear_bit(unsigned long nr, volatile void * addr)
|
|
{
|
|
unsigned long oldbit;
|
|
unsigned long temp;
|
|
volatile unsigned int *m = ((volatile unsigned int *) addr) + (nr >> 5);
|
|
|
|
__asm__ __volatile__(
|
|
"1: ldl_l %0,%1\n"
|
|
" and %0,%3,%2\n"
|
|
" beq %2,2f\n"
|
|
" xor %0,%3,%0\n"
|
|
" stl_c %0,%1\n"
|
|
" beq %0,3f\n"
|
|
"2:\n"
|
|
".section .text2,\"ax\"\n"
|
|
"3: br 1b\n"
|
|
".previous"
|
|
:"=&r" (temp), "=m" (*m), "=&r" (oldbit)
|
|
:"Ir" (1UL << (nr & 31)), "m" (*m));
|
|
return oldbit;
|
|
}
|
|
|
|
static __inline unsigned int change_bit(unsigned long nr, volatile void * addr)
|
|
{
|
|
unsigned long oldbit;
|
|
unsigned long temp;
|
|
volatile unsigned int *m = ((volatile unsigned int *) addr) + (nr >> 5);
|
|
|
|
__asm__ __volatile__(
|
|
"1: ldl_l %0,%1\n"
|
|
" xor %0,%2,%0\n"
|
|
" stl_c %0,%1\n"
|
|
" beq %0,3f\n"
|
|
".section .text2,\"ax\"\n"
|
|
"3: br 1b\n"
|
|
".previous"
|
|
:"=&r" (temp), "=m" (*m), "=&r" (oldbit)
|
|
:"Ir" (1UL << (nr & 31)), "m" (*m));
|
|
return oldbit;
|
|
}
|
|
|
|
static __inline unsigned int test_bit(int nr, volatile void * addr)
|
|
{
|
|
return 1UL & (((volatile int *) addr)[nr >> 5] >> (nr & 31));
|
|
}
|
|
|
|
/*
|
|
* ffz = Find First Zero in word. Undefined if no zero exists,
|
|
* so code should check against ~0UL first..
|
|
*
|
|
* Do a binary search on the bits. Due to the nature of large
|
|
* constants on the alpha, it is worthwhile to split the search.
|
|
*/
|
|
static __inline unsigned long ffz_b(unsigned long x)
|
|
{
|
|
unsigned long sum = 0;
|
|
|
|
x = ~x & -~x; /* set first 0 bit, clear others */
|
|
if (x & 0xF0) sum += 4;
|
|
if (x & 0xCC) sum += 2;
|
|
if (x & 0xAA) sum += 1;
|
|
|
|
return sum;
|
|
}
|
|
|
|
static __inline unsigned long ffz(unsigned long word)
|
|
{
|
|
#ifdef __alpha_cix__
|
|
/* Whee. EV6 can calculate it directly. */
|
|
unsigned long result;
|
|
__asm__("ctlz %1,%0" : "=r"(result) : "r"(~word));
|
|
return result;
|
|
#else
|
|
unsigned long bits, qofs, bofs;
|
|
|
|
__asm__("cmpbge %1,%2,%0" : "=r"(bits) : "r"(word), "r"(~0UL));
|
|
qofs = ffz_b(bits);
|
|
__asm__("extbl %1,%2,%0" : "=r"(bits) : "r"(word), "r"(qofs));
|
|
bofs = ffz_b(bits);
|
|
|
|
return qofs*8 + bofs;
|
|
#endif
|
|
}
|
|
|
|
#ifdef __KERNEL__
|
|
#if 0
|
|
/*
|
|
* 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 word)
|
|
{
|
|
int result = ffz(~word);
|
|
return word ? result+1 : 0;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* hweightN: returns the hamming weight (i.e. the number
|
|
* of bits set) of a N-bit word
|
|
*/
|
|
|
|
#ifdef __alpha_cix__
|
|
/* Whee. EV6 can calculate it directly. */
|
|
static __inline unsigned long hweight64(unsigned long w)
|
|
{
|
|
unsigned long result;
|
|
__asm__("ctpop %1,%0" : "=r"(result) : "r"(w));
|
|
return result;
|
|
}
|
|
|
|
#define hweight32(x) hweight64((x) & 0xfffffffful)
|
|
#define hweight16(x) hweight64((x) & 0xfffful)
|
|
#define hweight8(x) hweight64((x) & 0xfful)
|
|
#else
|
|
#define hweight32(x) generic_hweight32(x)
|
|
#define hweight16(x) generic_hweight16(x)
|
|
#define hweight8(x) generic_hweight8(x)
|
|
#endif
|
|
|
|
#endif /* __alpha_cix__ */
|
|
|
|
/* from lib/string.c */
|
|
static __inline void * memscan(void * addr, int c, size_t size)
|
|
{
|
|
unsigned char * p = (unsigned char *) addr;
|
|
|
|
while (size) {
|
|
if (*p == c)
|
|
return (void *) p;
|
|
p++;
|
|
size--;
|
|
}
|
|
return (void *) p;
|
|
}
|
|
|
|
|
|
/*
|
|
* Find next zero bit in a bitmap reasonably efficiently..
|
|
*/
|
|
static __inline unsigned long find_next_zero_bit(void * addr, unsigned long size, unsigned long offset)
|
|
{
|
|
unsigned long * p = ((unsigned long *) addr) + (offset >> 6);
|
|
unsigned long result = offset & ~63UL;
|
|
unsigned long tmp;
|
|
|
|
if (offset >= size)
|
|
return size;
|
|
size -= result;
|
|
offset &= 63UL;
|
|
if (offset) {
|
|
tmp = *(p++);
|
|
tmp |= ~0UL >> (64-offset);
|
|
if (size < 64)
|
|
goto found_first;
|
|
if (~tmp)
|
|
goto found_middle;
|
|
size -= 64;
|
|
result += 64;
|
|
}
|
|
while (size & ~63UL) {
|
|
if (~(tmp = *(p++)))
|
|
goto found_middle;
|
|
result += 64;
|
|
size -= 64;
|
|
}
|
|
if (!size)
|
|
return result;
|
|
tmp = *p;
|
|
found_first:
|
|
tmp |= ~0UL << size;
|
|
found_middle:
|
|
return result + ffz(tmp);
|
|
}
|
|
|
|
/*
|
|
* The optimizer actually does good code for this case..
|
|
*/
|
|
#define find_first_zero_bit(addr, size) \
|
|
find_next_zero_bit((addr), (size), 0)
|
|
|
|
#ifdef __KERNEL__
|
|
|
|
#define ext2_set_bit test_and_set_bit
|
|
#define ext2_clear_bit test_and_clear_bit
|
|
#define ext2_test_bit test_bit
|
|
#define ext2_find_first_zero_bit find_first_zero_bit
|
|
#define ext2_find_next_zero_bit find_next_zero_bit
|
|
|
|
/* Bitmap functions for the minix filesystem. */
|
|
#define minix_set_bit(nr,addr) test_and_set_bit(nr,addr)
|
|
#define minix_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 /* _ALPHA_BITOPS_H */
|