| 1 | #ifndef _I386_BITOPS_H
|
|---|
| 2 | #define _I386_BITOPS_H
|
|---|
| 3 |
|
|---|
| 4 | /*
|
|---|
| 5 | * Copyright 1992, Linus Torvalds.
|
|---|
| 6 | */
|
|---|
| 7 |
|
|---|
| 8 | /*
|
|---|
| 9 | * These have to be done with inline assembly: that way the bit-setting
|
|---|
| 10 | * is guaranteed to be atomic. All bit operations return 0 if the bit
|
|---|
| 11 | * was cleared before the operation and != 0 if it was not.
|
|---|
| 12 | *
|
|---|
| 13 | * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
|
|---|
| 14 | */
|
|---|
| 15 |
|
|---|
| 16 | /*
|
|---|
| 17 | * Function prototypes to keep gcc -Wall happy
|
|---|
| 18 | */
|
|---|
| 19 | #ifdef __WATCOMC__
|
|---|
| 20 | int set_bit(int nr, volatile void * addr);
|
|---|
| 21 | #pragma aux set_bit = \
|
|---|
| 22 | "bts dword ptr [esi], eax" \
|
|---|
| 23 | "setc al" \
|
|---|
| 24 | "movzx eax, al" \
|
|---|
| 25 | parm [eax] [esi] \
|
|---|
| 26 | value [eax]
|
|---|
| 27 |
|
|---|
| 28 | int clear_bit(int nr, volatile void * addr);
|
|---|
| 29 | #pragma aux clear_bit = \
|
|---|
| 30 | "btr dword ptr [esi], eax" \
|
|---|
| 31 | "setc al" \
|
|---|
| 32 | "movzx eax, al" \
|
|---|
| 33 | parm [eax] [esi] \
|
|---|
| 34 | value [eax]
|
|---|
| 35 |
|
|---|
| 36 | int change_bit(int nr, volatile void * addr);
|
|---|
| 37 | #pragma aux change_bit = \
|
|---|
| 38 | "btc dword ptr [esi], eax" \
|
|---|
| 39 | "setc al" \
|
|---|
| 40 | "movzx eax, al" \
|
|---|
| 41 | parm [eax] [esi] \
|
|---|
| 42 | value [eax]
|
|---|
| 43 |
|
|---|
| 44 | #define test_and_set_bit(nr, addr) set_bit(nr, addr)
|
|---|
| 45 | #define test_and_clear_bit(nr, addr) clear_bit(nr, addr)
|
|---|
| 46 | #define test_and_change_bit(nr, addr) change_bit(nr, addr)
|
|---|
| 47 |
|
|---|
| 48 | /*
|
|---|
| 49 | * ffs: find first bit set. This is defined the same way as
|
|---|
| 50 | * the libc and compiler builtin ffs routines, therefore
|
|---|
| 51 | * differs in spirit from the above ffz (man ffs).
|
|---|
| 52 | */
|
|---|
| 53 |
|
|---|
| 54 | int ffs(int x);
|
|---|
| 55 | #pragma aux ffs = \
|
|---|
| 56 | "bsf eax, ebx" \
|
|---|
| 57 | "jnz @f" \
|
|---|
| 58 | "mov eax, -1" \
|
|---|
| 59 | "@f:" \
|
|---|
| 60 | "inc eax" \
|
|---|
| 61 | parm [ebx] \
|
|---|
| 62 | value [eax]
|
|---|
| 63 |
|
|---|
| 64 | /*
|
|---|
| 65 | * ffz = Find First Zero in word. Undefined if no zero exists,
|
|---|
| 66 | * so code should check against ~0UL first..
|
|---|
| 67 | */
|
|---|
| 68 | unsigned long ffz(unsigned long word);
|
|---|
| 69 | #pragma aux ffz = \
|
|---|
| 70 | "bsf eax, ebx" \
|
|---|
| 71 | parm [ebx] \
|
|---|
| 72 | value [eax]
|
|---|
| 73 |
|
|---|
| 74 | //{
|
|---|
| 75 | // int r;
|
|---|
| 76 | //
|
|---|
| 77 | // __asm__("bsfl %1,%0\n\t"
|
|---|
| 78 | // "jnz 1f\n\t"
|
|---|
| 79 | // "movl $-1,%0\n"
|
|---|
| 80 | // "1:" : "=r" (r) : "g" (x));
|
|---|
| 81 | // return r+1;
|
|---|
| 82 | //}
|
|---|
| 83 |
|
|---|
| 84 | #else
|
|---|
| 85 | extern void set_bit(int nr, volatile void * addr);
|
|---|
| 86 | extern void clear_bit(int nr, volatile void * addr);
|
|---|
| 87 | extern void change_bit(int nr, volatile void * addr);
|
|---|
| 88 | extern int test_and_set_bit(int nr, volatile void * addr);
|
|---|
| 89 | extern int test_and_clear_bit(int nr, volatile void * addr);
|
|---|
| 90 | extern int test_and_change_bit(int nr, volatile void * addr);
|
|---|
| 91 | #endif
|
|---|
| 92 |
|
|---|
| 93 | extern int __constant_test_bit(int nr, const volatile void * addr);
|
|---|
| 94 | extern int __test_bit(int nr, volatile void * addr);
|
|---|
| 95 | extern int find_first_zero_bit(void * addr, unsigned size);
|
|---|
| 96 | extern int find_next_zero_bit (void * addr, int size, int offset);
|
|---|
| 97 |
|
|---|
| 98 | /*
|
|---|
| 99 | * This routine doesn't need to be atomic.
|
|---|
| 100 | */
|
|---|
| 101 | #define test_bit(nr, addr) (((1UL << (nr & 31)) & (((const unsigned int *) addr)[nr >> 5])) != 0)
|
|---|
| 102 |
|
|---|
| 103 | #endif /* _I386_BITOPS_H */
|
|---|
