/* * Copyright 1995, Russell King. * Various bits and pieces copyrights include: * Linus Torvalds (test_bit). * Big endian support: Copyright 2001, Nicolas Pitre * reworked by rmk. * * bit 0 is the LSB of an "unsigned long" quantity. * * 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 privileged * instructions (which are not available from user mode) to ensure * that they are atomic. */ #ifndef __ASM_ARM_BITOPS_H #define __ASM_ARM_BITOPS_H #include #define smp_mb__before_clear_bit() mb() #define smp_mb__after_clear_bit() mb() /* * These functions are the basis of our bit ops. * * First, the atomic bitops. These use native endian. */ static inline void ____atomic_set_bit(unsigned int bit, volatile unsigned long *p) { unsigned long flags; unsigned long mask = 1UL << (bit & 31); p += bit >> 5; local_irq_save(flags); *p |= mask; local_irq_restore(flags); } static inline void ____atomic_clear_bit(unsigned int bit, volatile unsigned long *p) { unsigned long flags; unsigned long mask = 1UL << (bit & 31); p += bit >> 5; local_irq_save(flags); *p &= ~mask; local_irq_restore(flags); } static inline void ____atomic_change_bit(unsigned int bit, volatile unsigned long *p) { unsigned long flags; unsigned long mask = 1UL << (bit & 31); p += bit >> 5; local_irq_save(flags); *p ^= mask; local_irq_restore(flags); } static inline int ____atomic_test_and_set_bit(unsigned int bit, volatile unsigned long *p) { unsigned long flags; unsigned int res; unsigned long mask = 1UL << (bit & 31); p += bit >> 5; local_irq_save(flags); res = *p; *p = res | mask; local_irq_restore(flags); return res & mask; } static inline int ____atomic_test_and_clear_bit(unsigned int bit, volatile unsigned long *p) { unsigned long flags; unsigned int res; unsigned long mask = 1UL << (bit & 31); p += bit >> 5; local_irq_save(flags); res = *p; *p = res & ~mask; local_irq_restore(flags); return res & mask; } static inline int ____atomic_test_and_change_bit(unsigned int bit, volatile unsigned long *p) { unsigned long flags; unsigned int res; unsigned long mask = 1UL << (bit & 31); p += bit >> 5; local_irq_save(flags); res = *p; *p = res ^ mask; local_irq_restore(flags); return res & mask; } //#include /* * A note about Endian-ness. * ------------------------- * * When the ARM is put into big endian mode via CR15, the processor * merely swaps the order of bytes within words, thus: * * ------------ physical data bus bits ----------- * D31 ... D24 D23 ... D16 D15 ... D8 D7 ... D0 * little byte 3 byte 2 byte 1 byte 0 * big byte 0 byte 1 byte 2 byte 3 * * This means that reading a 32-bit word at address 0 returns the same * value irrespective of the endian mode bit. * * Peripheral devices should be connected with the data bus reversed in * "Big Endian" mode. ARM Application Note 61 is applicable, and is * available from http://www.arm.com/. * * The following assumes that the data bus connectivity for big endian * mode has been followed. * * Note that bit 0 is defined to be 32-bit word bit 0, not byte 0 bit 0. */ /* * Little endian assembly bitops. nr = 0 -> byte 0 bit 0. */ extern void _set_bit_le(int nr, volatile unsigned long * p); extern void _clear_bit_le(int nr, volatile unsigned long * p); extern void _change_bit_le(int nr, volatile unsigned long * p); extern int _test_and_set_bit_le(int nr, volatile unsigned long * p); extern int _test_and_clear_bit_le(int nr, volatile unsigned long * p); extern int _test_and_change_bit_le(int nr, volatile unsigned long * p); extern int _find_first_zero_bit_le(const void * p, unsigned size); extern int _find_next_zero_bit_le(const void * p, int size, int offset); extern int _find_first_bit_le(const unsigned long *p, unsigned size); extern int _find_next_bit_le(const unsigned long *p, int size, int offset); /* * Big endian assembly bitops. nr = 0 -> byte 3 bit 0. */ extern void _set_bit_be(int nr, volatile unsigned long * p); extern void _clear_bit_be(int nr, volatile unsigned long * p); extern void _change_bit_be(int nr, volatile unsigned long * p); extern int _test_and_set_bit_be(int nr, volatile unsigned long * p); extern int _test_and_clear_bit_be(int nr, volatile unsigned long * p); extern int _test_and_change_bit_be(int nr, volatile unsigned long * p); extern int _find_first_zero_bit_be(const void * p, unsigned size); extern int _find_next_zero_bit_be(const void * p, int size, int offset); extern int _find_first_bit_be(const unsigned long *p, unsigned size); extern int _find_next_bit_be(const unsigned long *p, int size, int offset); /* * The __* form of bitops are non-atomic and may be reordered. */ #define ATOMIC_BITOP_LE(name,nr,p) \ (__builtin_constant_p(nr) ? \ ____atomic_##name(nr, p) : \ _##name##_le(nr,p)) #define ATOMIC_BITOP_BE(name,nr,p) \ (__builtin_constant_p(nr) ? \ ____atomic_##name(nr, p) : \ _##name##_be(nr,p)) #define NONATOMIC_BITOP(name,nr,p) \ (____nonatomic_##name(nr, p)) /* * These are the little endian, atomic definitions. */ #define set_bit(nr,p) ATOMIC_BITOP_LE(set_bit,nr,p) #define clear_bit(nr,p) ATOMIC_BITOP_LE(clear_bit,nr,p) #define change_bit(nr,p) ATOMIC_BITOP_LE(change_bit,nr,p) #define test_and_set_bit(nr,p) ATOMIC_BITOP_LE(test_and_set_bit,nr,p) #define test_and_clear_bit(nr,p) ATOMIC_BITOP_LE(test_and_clear_bit,nr,p) #define test_and_change_bit(nr,p) ATOMIC_BITOP_LE(test_and_change_bit,nr,p) #define find_first_zero_bit(p,sz) _find_first_zero_bit_le(p,sz) #define find_next_zero_bit(p,sz,off) _find_next_zero_bit_le(p,sz,off) #define find_first_bit(p,sz) _find_first_bit_le(p,sz) #define find_next_bit(p,sz,off) _find_next_bit_le(p,sz,off) #define WORD_BITOFF_TO_LE(x) ((x)) #if 0 #include #include #include #include #include #include #include #endif #define BITS_PER_LONG 32 #define BITOP_MASK(nr) (1UL << ((nr) % BITS_PER_LONG)) #define BITOP_WORD(nr) ((nr) / BITS_PER_LONG) static inline int test_bit(int nr, const volatile unsigned long *addr) { return 1UL & (addr[BITOP_WORD(nr)] >> (nr & (BITS_PER_LONG-1))); } #endif /* _ARM_BITOPS_H */