diff options
Diffstat (limited to 'include/asm-arm/bitops.h')
| -rw-r--r-- | include/asm-arm/bitops.h | 29 |
1 files changed, 13 insertions, 16 deletions
diff --git a/include/asm-arm/bitops.h b/include/asm-arm/bitops.h index 5dcfe966f..666efc117 100644 --- a/include/asm-arm/bitops.h +++ b/include/asm-arm/bitops.h @@ -1,26 +1,29 @@ -#ifndef __ASM_ARM_BITOPS_H -#define __ASM_ARM_BITOPS_H - /* * Copyright 1995, Russell King. * Various bits and pieces copyrights include: * Linus Torvalds (test_bit). - */ - -/* - * These should be done with inline assembly. - * All bit operations return 0 if the bit - * was cleared before the operation and != 0 if it was not. * * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1). + * + * Please note that the code in this file should never be included + * from user space. Many of these are not implemented in assembler + * since they would be too costly. Also, they require priviledged + * instructions (which are not available from user mode) to ensure + * that they are atomic. */ +#ifndef __ASM_ARM_BITOPS_H +#define __ASM_ARM_BITOPS_H + +#ifdef __KERNEL__ + /* - * Function prototypes to keep gcc -Wall happy + * Function prototypes to keep gcc -Wall happy. */ extern void set_bit(int nr, volatile void * addr); extern void clear_bit(int nr, volatile void * addr); extern void change_bit(int nr, volatile void * addr); + extern int test_and_set_bit(int nr, volatile void * addr); extern int test_and_clear_bit(int nr, volatile void * addr); extern int test_and_change_bit(int nr, volatile void * addr); @@ -53,8 +56,6 @@ extern __inline__ unsigned long ffz(unsigned long word) return k; } -#ifdef __KERNEL__ - /* * ffs: find first bit set. This is defined the same way as * the libc and compiler builtin ffs routines, therefore @@ -72,10 +73,6 @@ extern __inline__ unsigned long ffz(unsigned long word) #define hweight16(x) generic_hweight16(x) #define hweight8(x) generic_hweight8(x) -#endif /* __KERNEL__ */ - -#ifdef __KERNEL__ - #define ext2_set_bit test_and_set_bit #define ext2_clear_bit test_and_clear_bit #define ext2_test_bit test_bit |