| /* |
| * 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 |
| |
| #ifdef __KERNEL__ |
| |
| #include <asm/system.h> |
| |
| #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; |
| } |
| |
| /* |
| * Now the non-atomic variants. We let the compiler handle all |
| * optimisations for these. These are all _native_ endian. |
| */ |
| static inline void __set_bit(int nr, volatile unsigned long *p) |
| { |
| p[nr >> 5] |= (1UL << (nr & 31)); |
| } |
| |
| static inline void __clear_bit(int nr, volatile unsigned long *p) |
| { |
| p[nr >> 5] &= ~(1UL << (nr & 31)); |
| } |
| |
| static inline void __change_bit(int nr, volatile unsigned long *p) |
| { |
| p[nr >> 5] ^= (1UL << (nr & 31)); |
| } |
| |
| static inline int __test_and_set_bit(int nr, volatile unsigned long *p) |
| { |
| unsigned long oldval, mask = 1UL << (nr & 31); |
| |
| p += nr >> 5; |
| |
| oldval = *p; |
| *p = oldval | mask; |
| return oldval & mask; |
| } |
| |
| static inline int __test_and_clear_bit(int nr, volatile unsigned long *p) |
| { |
| unsigned long oldval, mask = 1UL << (nr & 31); |
| |
| p += nr >> 5; |
| |
| oldval = *p; |
| *p = oldval & ~mask; |
| return oldval & mask; |
| } |
| |
| static inline int __test_and_change_bit(int nr, volatile unsigned long *p) |
| { |
| unsigned long oldval, mask = 1UL << (nr & 31); |
| |
| p += nr >> 5; |
| |
| oldval = *p; |
| *p = oldval ^ mask; |
| return oldval & mask; |
| } |
| |
| /* |
| * This routine doesn't need to be atomic. |
| */ |
| static inline int __test_bit(int nr, const volatile unsigned long * p) |
| { |
| return (p[nr >> 5] >> (nr & 31)) & 1UL; |
| } |
| |
| /* |
| * 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); |
| |
| #ifndef CONFIG_SMP |
| /* |
| * 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)) |
| #else |
| #define ATOMIC_BITOP_LE(name,nr,p) _##name##_le(nr,p) |
| #define ATOMIC_BITOP_BE(name,nr,p) _##name##_be(nr,p) |
| #endif |
| |
| #define NONATOMIC_BITOP(name,nr,p) \ |
| (____nonatomic_##name(nr, p)) |
| |
| #ifndef __ARMEB__ |
| /* |
| * 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 test_bit(nr,p) __test_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)) |
| |
| #else |
| |
| /* |
| * These are the big endian, atomic definitions. |
| */ |
| #define set_bit(nr,p) ATOMIC_BITOP_BE(set_bit,nr,p) |
| #define clear_bit(nr,p) ATOMIC_BITOP_BE(clear_bit,nr,p) |
| #define change_bit(nr,p) ATOMIC_BITOP_BE(change_bit,nr,p) |
| #define test_and_set_bit(nr,p) ATOMIC_BITOP_BE(test_and_set_bit,nr,p) |
| #define test_and_clear_bit(nr,p) ATOMIC_BITOP_BE(test_and_clear_bit,nr,p) |
| #define test_and_change_bit(nr,p) ATOMIC_BITOP_BE(test_and_change_bit,nr,p) |
| #define test_bit(nr,p) __test_bit(nr,p) |
| #define find_first_zero_bit(p,sz) _find_first_zero_bit_be(p,sz) |
| #define find_next_zero_bit(p,sz,off) _find_next_zero_bit_be(p,sz,off) |
| #define find_first_bit(p,sz) _find_first_bit_be(p,sz) |
| #define find_next_bit(p,sz,off) _find_next_bit_be(p,sz,off) |
| |
| #define WORD_BITOFF_TO_LE(x) ((x) ^ 0x18) |
| |
| #endif |
| |
| #if __LINUX_ARM_ARCH__ < 5 |
| |
| /* |
| * ffz = Find First Zero in word. Undefined if no zero exists, |
| * so code should check against ~0UL first.. |
| */ |
| static inline unsigned long ffz(unsigned long word) |
| { |
| int k; |
| |
| word = ~word; |
| k = 31; |
| if (word & 0x0000ffff) { k -= 16; word <<= 16; } |
| if (word & 0x00ff0000) { k -= 8; word <<= 8; } |
| if (word & 0x0f000000) { k -= 4; word <<= 4; } |
| if (word & 0x30000000) { k -= 2; word <<= 2; } |
| if (word & 0x40000000) { k -= 1; } |
| return k; |
| } |
| |
| /* |
| * ffz = Find First Zero in word. Undefined if no zero exists, |
| * so code should check against ~0UL first.. |
| */ |
| static inline unsigned long __ffs(unsigned long word) |
| { |
| int k; |
| |
| k = 31; |
| if (word & 0x0000ffff) { k -= 16; word <<= 16; } |
| if (word & 0x00ff0000) { k -= 8; word <<= 8; } |
| if (word & 0x0f000000) { k -= 4; word <<= 4; } |
| if (word & 0x30000000) { k -= 2; word <<= 2; } |
| if (word & 0x40000000) { k -= 1; } |
| return k; |
| } |
| |
| /* |
| * fls: find last bit set. |
| */ |
| |
| #define fls(x) generic_fls(x) |
| |
| /* |
| * 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). |
| */ |
| |
| #define ffs(x) generic_ffs(x) |
| |
| #else |
| |
| /* |
| * On ARMv5 and above those functions can be implemented around |
| * the clz instruction for much better code efficiency. |
| */ |
| |
| #define fls(x) \ |
| ( __builtin_constant_p(x) ? generic_fls(x) : \ |
| ({ int __r; asm("clz\t%0, %1" : "=r"(__r) : "r"(x) : "cc"); 32-__r; }) ) |
| #define ffs(x) ({ unsigned long __t = (x); fls(__t & -__t); }) |
| #define __ffs(x) (ffs(x) - 1) |
| #define ffz(x) __ffs( ~(x) ) |
| |
| #endif |
| |
| /* |
| * Find first bit set in a 168-bit bitmap, where the first |
| * 128 bits are unlikely to be set. |
| */ |
| static inline int sched_find_first_bit(const unsigned long *b) |
| { |
| unsigned long v; |
| unsigned int off; |
| |
| for (off = 0; v = b[off], off < 4; off++) { |
| if (unlikely(v)) |
| break; |
| } |
| return __ffs(v) + off * 32; |
| } |
| |
| /* |
| * hweightN: returns the hamming weight (i.e. the number |
| * of bits set) of a N-bit word |
| */ |
| |
| #define hweight32(x) generic_hweight32(x) |
| #define hweight16(x) generic_hweight16(x) |
| #define hweight8(x) generic_hweight8(x) |
| |
| /* |
| * Ext2 is defined to use little-endian byte ordering. |
| * These do not need to be atomic. |
| */ |
| #define ext2_set_bit(nr,p) \ |
| __test_and_set_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p)) |
| #define ext2_set_bit_atomic(lock,nr,p) \ |
| test_and_set_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p)) |
| #define ext2_clear_bit(nr,p) \ |
| __test_and_clear_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p)) |
| #define ext2_clear_bit_atomic(lock,nr,p) \ |
| test_and_clear_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p)) |
| #define ext2_test_bit(nr,p) \ |
| __test_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p)) |
| #define ext2_find_first_zero_bit(p,sz) \ |
| _find_first_zero_bit_le(p,sz) |
| #define ext2_find_next_zero_bit(p,sz,off) \ |
| _find_next_zero_bit_le(p,sz,off) |
| |
| /* |
| * Minix is defined to use little-endian byte ordering. |
| * These do not need to be atomic. |
| */ |
| #define minix_set_bit(nr,p) \ |
| __set_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p)) |
| #define minix_test_bit(nr,p) \ |
| __test_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p)) |
| #define minix_test_and_set_bit(nr,p) \ |
| __test_and_set_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p)) |
| #define minix_test_and_clear_bit(nr,p) \ |
| __test_and_clear_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p)) |
| #define minix_find_first_zero_bit(p,sz) \ |
| _find_first_zero_bit_le(p,sz) |
| |
| #endif /* __KERNEL__ */ |
| |
| #endif /* _ARM_BITOPS_H */ |