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Diffstat (limited to 'firmware/include/asm/bitops.h')
| -rw-r--r-- | firmware/include/asm/bitops.h | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/firmware/include/asm/bitops.h b/firmware/include/asm/bitops.h new file mode 100644 index 0000000..337d800 --- /dev/null +++ b/firmware/include/asm/bitops.h @@ -0,0 +1,225 @@ +/* + * 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 <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; +} + +//#include <asm-generic/bitops/non-atomic.h> + +/* + * 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 <asm-generic/bitops/ffz.h> +#include <asm-generic/bitops/__ffs.h> +#include <asm-generic/bitops/fls.h> +#include <asm-generic/bitops/ffs.h> + +#include <asm-generic/bitops/fls64.h> + +#include <asm-generic/bitops/sched.h> +#include <asm-generic/bitops/hweight.h> +#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 */ |