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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 | /* * Copyright (C) 1996 Paul Mackerras. */ #include <linux/kernel.h> #include <asm/bitops.h> /* * I left these here since the problems with "cc" make it difficult to keep * them in bitops.h -- Cort */ void set_bit(int nr, volatile void *addr) { unsigned int t; unsigned int mask = 1 << (nr & 0x1f); volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5); if ((unsigned long)addr & 3) printk(KERN_ERR "set_bit(%x, %p)\n", nr, addr); __asm__ __volatile__("\n\ 1: lwarx %0,0,%2 or %0,%0,%1 stwcx. %0,0,%2 bne 1b" : "=&r" (t) /*, "=m" (*p)*/ : "r" (mask), "r" (p) : "cc"); } void clear_bit(int nr, volatile void *addr) { unsigned int t; unsigned int mask = 1 << (nr & 0x1f); volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5); if ((unsigned long)addr & 3) printk(KERN_ERR "clear_bit(%x, %p)\n", nr, addr); __asm__ __volatile__("\n\ 1: lwarx %0,0,%2 andc %0,%0,%1 stwcx. %0,0,%2 bne 1b" : "=&r" (t) /*, "=m" (*p)*/ : "r" (mask), "r" (p) : "cc"); } void change_bit(int nr, volatile void *addr) { unsigned int t; unsigned int mask = 1 << (nr & 0x1f); volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5); if ((unsigned long)addr & 3) printk(KERN_ERR "change_bit(%x, %p)\n", nr, addr); __asm__ __volatile__("\n\ 1: lwarx %0,0,%2 xor %0,%0,%1 stwcx. %0,0,%2 bne 1b" : "=&r" (t) /*, "=m" (*p)*/ : "r" (mask), "r" (p) : "cc"); } int test_and_set_bit(int nr, volatile void *addr) { unsigned int old, t; unsigned int mask = 1 << (nr & 0x1f); volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5); if ((unsigned long)addr & 3) printk(KERN_ERR "test_and_set_bit(%x, %p)\n", nr, addr); __asm__ __volatile__("\n\ 1: lwarx %0,0,%3 or %1,%0,%2 stwcx. %1,0,%3 bne 1b" : "=&r" (old), "=&r" (t) /*, "=m" (*p)*/ : "r" (mask), "r" (p) : "cc"); return (old & mask) != 0; } int test_and_clear_bit(int nr, volatile void *addr) { unsigned int old, t; unsigned int mask = 1 << (nr & 0x1f); volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5); if ((unsigned long)addr & 3) printk(KERN_ERR "test_and_clear_bit(%x, %p)\n", nr, addr); __asm__ __volatile__("\n\ 1: lwarx %0,0,%3 andc %1,%0,%2 stwcx. %1,0,%3 bne 1b" : "=&r" (old), "=&r" (t) /*, "=m" (*p)*/ : "r" (mask), "r" (p) : "cc"); return (old & mask) != 0; } int test_and_change_bit(int nr, volatile void *addr) { unsigned int old, t; unsigned int mask = 1 << (nr & 0x1f); volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5); if ((unsigned long)addr & 3) printk(KERN_ERR "test_and_change_bit(%x, %p)\n", nr, addr); __asm__ __volatile__("\n\ 1: lwarx %0,0,%3 xor %1,%0,%2 stwcx. %1,0,%3 bne 1b" : "=&r" (old), "=&r" (t) /*, "=m" (*p)*/ : "r" (mask), "r" (p) : "cc"); return (old & mask) != 0; } /* I put it in bitops.h -- Cort */ #if 0 int ffz(unsigned int x) { int n; x = ~x & (x+1); /* set LS zero to 1, other bits to 0 */ __asm__ ("cntlzw %0,%1" : "=r" (n) : "r" (x)); return 31 - n; } /* * This implementation of find_{first,next}_zero_bit was stolen from * Linus' asm-alpha/bitops.h. */ int find_first_zero_bit(void * addr, int size) { unsigned int * p = ((unsigned int *) addr); unsigned int result = 0; unsigned int tmp; if (size == 0) return 0; while (size & ~31UL) { if (~(tmp = *(p++))) goto found_middle; result += 32; size -= 32; } if (!size) return result; tmp = *p; tmp |= ~0UL << size; found_middle: return result + ffz(tmp); } /* * Find next zero bit in a bitmap reasonably efficiently.. */ int find_next_zero_bit(void * addr, int size, int offset) { unsigned int * p = ((unsigned int *) addr) + (offset >> 5); unsigned int result = offset & ~31UL; unsigned int tmp; if (offset >= size) return size; size -= result; offset &= 31UL; if (offset) { tmp = *(p++); tmp |= ~0UL >> (32-offset); if (size < 32) goto found_first; if (~tmp) goto found_middle; size -= 32; result += 32; } while (size & ~31UL) { if (~(tmp = *(p++))) goto found_middle; result += 32; size -= 32; } if (!size) return result; tmp = *p; found_first: tmp |= ~0UL << size; found_middle: return result + ffz(tmp); } #endif |