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Diffstat (limited to 'include/asm-alpha/bitops.h')
| -rw-r--r-- | include/asm-alpha/bitops.h | 507 |
1 files changed, 507 insertions, 0 deletions
diff --git a/include/asm-alpha/bitops.h b/include/asm-alpha/bitops.h new file mode 100644 index 000000000000..578ed3f1a607 --- /dev/null +++ b/include/asm-alpha/bitops.h @@ -0,0 +1,507 @@ +#ifndef _ALPHA_BITOPS_H +#define _ALPHA_BITOPS_H + +#include <linux/config.h> +#include <asm/compiler.h> + +/* + * Copyright 1994, Linus Torvalds. + */ + +/* + * These have to be done with inline assembly: that way the bit-setting + * is guaranteed to be atomic. All bit operations return 0 if the bit + * was cleared before the operation and != 0 if it was not. + * + * To get proper branch prediction for the main line, we must branch + * forward to code at the end of this object's .text section, then + * branch back to restart the operation. + * + * bit 0 is the LSB of addr; bit 64 is the LSB of (addr+1). + */ + +static inline void +set_bit(unsigned long nr, volatile void * addr) +{ + unsigned long temp; + int *m = ((int *) addr) + (nr >> 5); + + __asm__ __volatile__( + "1: ldl_l %0,%3\n" + " bis %0,%2,%0\n" + " stl_c %0,%1\n" + " beq %0,2f\n" + ".subsection 2\n" + "2: br 1b\n" + ".previous" + :"=&r" (temp), "=m" (*m) + :"Ir" (1UL << (nr & 31)), "m" (*m)); +} + +/* + * WARNING: non atomic version. + */ +static inline void +__set_bit(unsigned long nr, volatile void * addr) +{ + int *m = ((int *) addr) + (nr >> 5); + + *m |= 1 << (nr & 31); +} + +#define smp_mb__before_clear_bit() smp_mb() +#define smp_mb__after_clear_bit() smp_mb() + +static inline void +clear_bit(unsigned long nr, volatile void * addr) +{ + unsigned long temp; + int *m = ((int *) addr) + (nr >> 5); + + __asm__ __volatile__( + "1: ldl_l %0,%3\n" + " bic %0,%2,%0\n" + " stl_c %0,%1\n" + " beq %0,2f\n" + ".subsection 2\n" + "2: br 1b\n" + ".previous" + :"=&r" (temp), "=m" (*m) + :"Ir" (1UL << (nr & 31)), "m" (*m)); +} + +/* + * WARNING: non atomic version. + */ +static __inline__ void +__clear_bit(unsigned long nr, volatile void * addr) +{ + int *m = ((int *) addr) + (nr >> 5); + + *m &= ~(1 << (nr & 31)); +} + +static inline void +change_bit(unsigned long nr, volatile void * addr) +{ + unsigned long temp; + int *m = ((int *) addr) + (nr >> 5); + + __asm__ __volatile__( + "1: ldl_l %0,%3\n" + " xor %0,%2,%0\n" + " stl_c %0,%1\n" + " beq %0,2f\n" + ".subsection 2\n" + "2: br 1b\n" + ".previous" + :"=&r" (temp), "=m" (*m) + :"Ir" (1UL << (nr & 31)), "m" (*m)); +} + +/* + * WARNING: non atomic version. + */ +static __inline__ void +__change_bit(unsigned long nr, volatile void * addr) +{ + int *m = ((int *) addr) + (nr >> 5); + + *m ^= 1 << (nr & 31); +} + +static inline int +test_and_set_bit(unsigned long nr, volatile void *addr) +{ + unsigned long oldbit; + unsigned long temp; + int *m = ((int *) addr) + (nr >> 5); + + __asm__ __volatile__( + "1: ldl_l %0,%4\n" + " and %0,%3,%2\n" + " bne %2,2f\n" + " xor %0,%3,%0\n" + " stl_c %0,%1\n" + " beq %0,3f\n" + "2:\n" +#ifdef CONFIG_SMP + " mb\n" +#endif + ".subsection 2\n" + "3: br 1b\n" + ".previous" + :"=&r" (temp), "=m" (*m), "=&r" (oldbit) + :"Ir" (1UL << (nr & 31)), "m" (*m) : "memory"); + + return oldbit != 0; +} + +/* + * WARNING: non atomic version. + */ +static inline int +__test_and_set_bit(unsigned long nr, volatile void * addr) +{ + unsigned long mask = 1 << (nr & 0x1f); + int *m = ((int *) addr) + (nr >> 5); + int old = *m; + + *m = old | mask; + return (old & mask) != 0; +} + +static inline int +test_and_clear_bit(unsigned long nr, volatile void * addr) +{ + unsigned long oldbit; + unsigned long temp; + int *m = ((int *) addr) + (nr >> 5); + + __asm__ __volatile__( + "1: ldl_l %0,%4\n" + " and %0,%3,%2\n" + " beq %2,2f\n" + " xor %0,%3,%0\n" + " stl_c %0,%1\n" + " beq %0,3f\n" + "2:\n" +#ifdef CONFIG_SMP + " mb\n" +#endif + ".subsection 2\n" + "3: br 1b\n" + ".previous" + :"=&r" (temp), "=m" (*m), "=&r" (oldbit) + :"Ir" (1UL << (nr & 31)), "m" (*m) : "memory"); + + return oldbit != 0; +} + +/* + * WARNING: non atomic version. + */ +static inline int +__test_and_clear_bit(unsigned long nr, volatile void * addr) +{ + unsigned long mask = 1 << (nr & 0x1f); + int *m = ((int *) addr) + (nr >> 5); + int old = *m; + + *m = old & ~mask; + return (old & mask) != 0; +} + +static inline int +test_and_change_bit(unsigned long nr, volatile void * addr) +{ + unsigned long oldbit; + unsigned long temp; + int *m = ((int *) addr) + (nr >> 5); + + __asm__ __volatile__( + "1: ldl_l %0,%4\n" + " and %0,%3,%2\n" + " xor %0,%3,%0\n" + " stl_c %0,%1\n" + " beq %0,3f\n" +#ifdef CONFIG_SMP + " mb\n" +#endif + ".subsection 2\n" + "3: br 1b\n" + ".previous" + :"=&r" (temp), "=m" (*m), "=&r" (oldbit) + :"Ir" (1UL << (nr & 31)), "m" (*m) : "memory"); + + return oldbit != 0; +} + +/* + * WARNING: non atomic version. + */ +static __inline__ int +__test_and_change_bit(unsigned long nr, volatile void * addr) +{ + unsigned long mask = 1 << (nr & 0x1f); + int *m = ((int *) addr) + (nr >> 5); + int old = *m; + + *m = old ^ mask; + return (old & mask) != 0; +} + +static inline int +test_bit(int nr, const volatile void * addr) +{ + return (1UL & (((const int *) addr)[nr >> 5] >> (nr & 31))) != 0UL; +} + +/* + * ffz = Find First Zero in word. Undefined if no zero exists, + * so code should check against ~0UL first.. + * + * Do a binary search on the bits. Due to the nature of large + * constants on the alpha, it is worthwhile to split the search. + */ +static inline unsigned long ffz_b(unsigned long x) +{ + unsigned long sum, x1, x2, x4; + + x = ~x & -~x; /* set first 0 bit, clear others */ + x1 = x & 0xAA; + x2 = x & 0xCC; + x4 = x & 0xF0; + sum = x2 ? 2 : 0; + sum += (x4 != 0) * 4; + sum += (x1 != 0); + + return sum; +} + +static inline unsigned long ffz(unsigned long word) +{ +#if defined(__alpha_cix__) && defined(__alpha_fix__) + /* Whee. EV67 can calculate it directly. */ + return __kernel_cttz(~word); +#else + unsigned long bits, qofs, bofs; + + bits = __kernel_cmpbge(word, ~0UL); + qofs = ffz_b(bits); + bits = __kernel_extbl(word, qofs); + bofs = ffz_b(bits); + + return qofs*8 + bofs; +#endif +} + +/* + * __ffs = Find First set bit in word. Undefined if no set bit exists. + */ +static inline unsigned long __ffs(unsigned long word) +{ +#if defined(__alpha_cix__) && defined(__alpha_fix__) + /* Whee. EV67 can calculate it directly. */ + return __kernel_cttz(word); +#else + unsigned long bits, qofs, bofs; + + bits = __kernel_cmpbge(0, word); + qofs = ffz_b(bits); + bits = __kernel_extbl(word, qofs); + bofs = ffz_b(~bits); + + return qofs*8 + bofs; +#endif +} + +#ifdef __KERNEL__ + +/* + * 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 __ffs. + */ + +static inline int ffs(int word) +{ + int result = __ffs(word) + 1; + return word ? result : 0; +} + +/* + * fls: find last bit set. + */ +#if defined(__alpha_cix__) && defined(__alpha_fix__) +static inline int fls(int word) +{ + return 64 - __kernel_ctlz(word & 0xffffffff); +} +#else +#define fls generic_fls +#endif + +/* Compute powers of two for the given integer. */ +static inline long floor_log2(unsigned long word) +{ +#if defined(__alpha_cix__) && defined(__alpha_fix__) + return 63 - __kernel_ctlz(word); +#else + long bit; + for (bit = -1; word ; bit++) + word >>= 1; + return bit; +#endif +} + +static inline long ceil_log2(unsigned long word) +{ + long bit = floor_log2(word); + return bit + (word > (1UL << bit)); +} + +/* + * hweightN: returns the hamming weight (i.e. the number + * of bits set) of a N-bit word + */ + +#if defined(__alpha_cix__) && defined(__alpha_fix__) +/* Whee. EV67 can calculate it directly. */ +static inline unsigned long hweight64(unsigned long w) +{ + return __kernel_ctpop(w); +} + +#define hweight32(x) (unsigned int) hweight64((x) & 0xfffffffful) +#define hweight16(x) (unsigned int) hweight64((x) & 0xfffful) +#define hweight8(x) (unsigned int) hweight64((x) & 0xfful) +#else +static inline unsigned long hweight64(unsigned long w) +{ + unsigned long result; + for (result = 0; w ; w >>= 1) + result += (w & 1); + return result; +} + +#define hweight32(x) generic_hweight32(x) +#define hweight16(x) generic_hweight16(x) +#define hweight8(x) generic_hweight8(x) +#endif + +#endif /* __KERNEL__ */ + +/* + * Find next zero bit in a bitmap reasonably efficiently.. + */ +static inline unsigned long +find_next_zero_bit(const void *addr, unsigned long size, unsigned long offset) +{ + const unsigned long *p = addr; + unsigned long result = offset & ~63UL; + unsigned long tmp; + + p += offset >> 6; + if (offset >= size) + return size; + size -= result; + offset &= 63UL; + if (offset) { + tmp = *(p++); + tmp |= ~0UL >> (64-offset); + if (size < 64) + goto found_first; + if (~tmp) + goto found_middle; + size -= 64; + result += 64; + } + while (size & ~63UL) { + if (~(tmp = *(p++))) + goto found_middle; + result += 64; + size -= 64; + } + if (!size) + return result; + tmp = *p; + found_first: + tmp |= ~0UL << size; + if (tmp == ~0UL) /* Are any bits zero? */ + return result + size; /* Nope. */ + found_middle: + return result + ffz(tmp); +} + +/* + * Find next one bit in a bitmap reasonably efficiently. + */ +static inline unsigned long +find_next_bit(const void * addr, unsigned long size, unsigned long offset) +{ + const unsigned long *p = addr; + unsigned long result = offset & ~63UL; + unsigned long tmp; + + p += offset >> 6; + if (offset >= size) + return size; + size -= result; + offset &= 63UL; + if (offset) { + tmp = *(p++); + tmp &= ~0UL << offset; + if (size < 64) + goto found_first; + if (tmp) + goto found_middle; + size -= 64; + result += 64; + } + while (size & ~63UL) { + if ((tmp = *(p++))) + goto found_middle; + result += 64; + size -= 64; + } + if (!size) + return result; + tmp = *p; + found_first: + tmp &= ~0UL >> (64 - size); + if (!tmp) + return result + size; + found_middle: + return result + __ffs(tmp); +} + +/* + * The optimizer actually does good code for this case. + */ +#define find_first_zero_bit(addr, size) \ + find_next_zero_bit((addr), (size), 0) +#define find_first_bit(addr, size) \ + find_next_bit((addr), (size), 0) + +#ifdef __KERNEL__ + +/* + * Every architecture must define this function. It's the fastest + * way of searching a 140-bit bitmap where the first 100 bits are + * unlikely to be set. It's guaranteed that at least one of the 140 + * bits is set. + */ +static inline unsigned long +sched_find_first_bit(unsigned long b[3]) +{ + unsigned long b0 = b[0], b1 = b[1], b2 = b[2]; + unsigned long ofs; + + ofs = (b1 ? 64 : 128); + b1 = (b1 ? b1 : b2); + ofs = (b0 ? 0 : ofs); + b0 = (b0 ? b0 : b1); + + return __ffs(b0) + ofs; +} + + +#define ext2_set_bit __test_and_set_bit +#define ext2_set_bit_atomic(l,n,a) test_and_set_bit(n,a) +#define ext2_clear_bit __test_and_clear_bit +#define ext2_clear_bit_atomic(l,n,a) test_and_clear_bit(n,a) +#define ext2_test_bit test_bit +#define ext2_find_first_zero_bit find_first_zero_bit +#define ext2_find_next_zero_bit find_next_zero_bit + +/* Bitmap functions for the minix filesystem. */ +#define minix_test_and_set_bit(nr,addr) __test_and_set_bit(nr,addr) +#define minix_set_bit(nr,addr) __set_bit(nr,addr) +#define minix_test_and_clear_bit(nr,addr) __test_and_clear_bit(nr,addr) +#define minix_test_bit(nr,addr) test_bit(nr,addr) +#define minix_find_first_zero_bit(addr,size) find_first_zero_bit(addr,size) + +#endif /* __KERNEL__ */ + +#endif /* _ALPHA_BITOPS_H */ |