#ifndef _ALPHA_BITOPS_H #define _ALPHA_BITOPS_H #include #include /* * 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). */ extern __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. */ extern __inline__ void __set_bit(unsigned long nr, volatile void * addr) { int *m = ((int *) addr) + (nr >> 5); *m |= 1UL << (nr & 31); } #define smp_mb__before_clear_bit() smp_mb() #define smp_mb__after_clear_bit() smp_mb() extern __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" " and %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)); } extern __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)); } extern __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. */ extern __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; } extern __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. */ extern __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; } extern __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; } extern __inline__ int test_bit(int nr, 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. */ extern inline unsigned long ffz_b(unsigned long x) { unsigned long sum = 0; x = ~x & -~x; /* set first 0 bit, clear others */ if (x & 0xF0) sum += 4; if (x & 0xCC) sum += 2; if (x & 0xAA) sum += 1; return sum; } extern inline unsigned long ffz(unsigned long word) { #if defined(__alpha_cix__) && defined(__alpha_fix__) /* Whee. EV67 can calculate it directly. */ unsigned long result; __asm__("cttz %1,%0" : "=r"(result) : "r"(~word)); return result; #else unsigned long bits, qofs, bofs; __asm__("cmpbge %1,%2,%0" : "=r"(bits) : "r"(word), "r"(~0UL)); qofs = ffz_b(bits); __asm__("extbl %1,%2,%0" : "=r"(bits) : "r"(word), "r"(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 ffz (man ffs). */ extern inline int ffs(int word) { int result = ffz(~word); return word ? result+1 : 0; } /* * 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. */ extern __inline__ unsigned long hweight64(unsigned long w) { unsigned long result; __asm__("ctpop %1,%0" : "=r"(result) : "r"(w)); return result; } #define hweight32(x) hweight64((x) & 0xfffffffful) #define hweight16(x) hweight64((x) & 0xfffful) #define hweight8(x) hweight64((x) & 0xfful) #else #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.. */ extern inline unsigned long find_next_zero_bit(void * addr, unsigned long size, unsigned long offset) { unsigned long * p = ((unsigned long *) addr) + (offset >> 6); unsigned long result = offset & ~63UL; unsigned long tmp; 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); } /* * The optimizer actually does good code for this case.. */ #define find_first_zero_bit(addr, size) \ find_next_zero_bit((addr), (size), 0) #ifdef __KERNEL__ #define ext2_set_bit __test_and_set_bit #define ext2_clear_bit __test_and_clear_bit #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 */