include/asm-mn10300/bitops.h

   1 /* MN10300 bit operations
   2  *
   3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public Licence
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the Licence, or (at your option) any later version.
  10  *
  11  * These have to be done with inline assembly: that way the bit-setting
  12  * is guaranteed to be atomic. All bit operations return 0 if the bit
  13  * was cleared before the operation and != 0 if it was not.
  14  *
  15  * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
  16  */
  17 #ifndef __ASM_BITOPS_H
  18 #define __ASM_BITOPS_H
  19
  20 #include <asm/cpu-regs.h>
  21
  22 #define smp_mb__before_clear_bit()      barrier()
  23 #define smp_mb__after_clear_bit()       barrier()
  24
  25 /*
  26  * set bit
  27  */
  28 #define __set_bit(nr, addr)                                     \
  29 ({                                                              \
  30         volatile unsigned char *_a = (unsigned char *)(addr);   \
  31         const unsigned shift = (nr) & 7;                        \
  32         _a += (nr) >> 3;                                        \
  33                                                                 \
  34         asm volatile("bset %2,(%1) # set_bit reg"               \
  35                      : "=m"(*_a)                                \
  36                      : "a"(_a), "d"(1 << shift),  "m"(*_a)      \
  37                      : "memory", "cc");                         \
  38 })
  39
  40 #define set_bit(nr, addr) __set_bit((nr), (addr))
  41
  42 /*
  43  * clear bit
  44  */
  45 #define ___clear_bit(nr, addr)                                  \
  46 ({                                                              \
  47         volatile unsigned char *_a = (unsigned char *)(addr);   \
  48         const unsigned shift = (nr) & 7;                        \
  49         _a += (nr) >> 3;                                        \
  50                                                                 \
  51         asm volatile("bclr %2,(%1) # clear_bit reg"             \
  52                      : "=m"(*_a)                                \
  53                      : "a"(_a), "d"(1 << shift), "m"(*_a)       \
  54                      : "memory", "cc");                         \
  55 })
  56
  57 #define clear_bit(nr, addr) ___clear_bit((nr), (addr))
  58
  59
  60 static inline void __clear_bit(int nr, volatile void *addr)
  61 {
  62         unsigned int *a = (unsigned int *) addr;
  63         int mask;
  64
  65         a += nr >> 5;
  66         mask = 1 << (nr & 0x1f);
  67         *a &= ~mask;
  68 }
  69
  70 /*
  71  * test bit
  72  */
  73 static inline int test_bit(int nr, const volatile void *addr)
  74 {
  75         return 1UL & (((const unsigned int *) addr)[nr >> 5] >> (nr & 31));
  76 }
  77
  78 /*
  79  * change bit
  80  */
  81 static inline void __change_bit(int nr, volatile void *addr)
  82 {
  83         int     mask;
  84         unsigned int *a = (unsigned int *) addr;
  85
  86         a += nr >> 5;
  87         mask = 1 << (nr & 0x1f);
  88         *a ^= mask;
  89 }
  90
  91 extern void change_bit(int nr, volatile void *addr);
  92
  93 /*
  94  * test and set bit
  95  */
  96 #define __test_and_set_bit(nr,addr)                             \
  97 ({                                                              \
  98         volatile unsigned char *_a = (unsigned char *)(addr);   \
  99         const unsigned shift = (nr) & 7;                        \
 100         unsigned epsw;                                          \
 101         _a += (nr) >> 3;                                        \
 102                                                                 \
 103         asm volatile("bset %3,(%2) # test_set_bit reg\n"        \
 104                      "mov epsw,%1"                              \
 105                      : "=m"(*_a), "=d"(epsw)                    \
 106                      : "a"(_a), "d"(1 << shift), "m"(*_a)       \
 107                      : "memory", "cc");                         \
 108                                                                 \
 109         !(epsw & EPSW_FLAG_Z);                                  \
 110 })
 111
 112 #define test_and_set_bit(nr, addr) __test_and_set_bit((nr), (addr))
 113
 114 /*
 115  * test and clear bit
 116  */
 117 #define __test_and_clear_bit(nr, addr)                          \
 118 ({                                                              \
 119         volatile unsigned char *_a = (unsigned char *)(addr);   \
 120         const unsigned shift = (nr) & 7;                        \
 121         unsigned epsw;                                          \
 122         _a += (nr) >> 3;                                        \
 123                                                                 \
 124         asm volatile("bclr %3,(%2) # test_clear_bit reg\n"      \
 125                      "mov epsw,%1"                              \
 126                      : "=m"(*_a), "=d"(epsw)                    \
 127                      : "a"(_a), "d"(1 << shift), "m"(*_a)       \
 128                      : "memory", "cc");                         \
 129                                                                 \
 130         !(epsw & EPSW_FLAG_Z);                                  \
 131 })
 132
 133 #define test_and_clear_bit(nr, addr) __test_and_clear_bit((nr), (addr))
 134
 135 /*
 136  * test and change bit
 137  */
 138 static inline int __test_and_change_bit(int nr, volatile void *addr)
 139 {
 140         int     mask, retval;
 141         unsigned int *a = (unsigned int *)addr;
 142
 143         a += nr >> 5;
 144         mask = 1 << (nr & 0x1f);
 145         retval = (mask & *a) != 0;
 146         *a ^= mask;
 147
 148         return retval;
 149 }
 150
 151 extern int test_and_change_bit(int nr, volatile void *addr);
 152
 153 #include <asm-generic/bitops/lock.h>
 154
 155 #ifdef __KERNEL__
 156
 157 /**
 158  * __ffs - find first bit set
 159  * @x: the word to search
 160  *
 161  * - return 31..0 to indicate bit 31..0 most least significant bit set
 162  * - if no bits are set in x, the result is undefined
 163  */
 164 static inline __attribute__((const))
 165 unsigned long __ffs(unsigned long x)
 166 {
 167         int bit;
 168         asm("bsch %2,%0" : "=r"(bit) : "0"(0), "r"(x & -x));
 169         return bit;
 170 }
 171
 172 /*
 173  * special slimline version of fls() for calculating ilog2_u32()
 174  * - note: no protection against n == 0
 175  */
 176 static inline __attribute__((const))
 177 int __ilog2_u32(u32 n)
 178 {
 179         int bit;
 180         asm("bsch %2,%0" : "=r"(bit) : "0"(0), "r"(n));
 181         return bit;
 182 }
 183
 184 /**
 185  * fls - find last bit set
 186  * @x: the word to search
 187  *
 188  * This is defined the same way as ffs:
 189  * - return 32..1 to indicate bit 31..0 most significant bit set
 190  * - return 0 to indicate no bits set
 191  */
 192 static inline __attribute__((const))
 193 int fls(int x)
 194 {
 195         return (x != 0) ? __ilog2_u32(x) + 1 : 0;
 196 }
 197
 198 /**
 199  * ffs - find first bit set
 200  * @x: the word to search
 201  *
 202  * - return 32..1 to indicate bit 31..0 most least significant bit set
 203  * - return 0 to indicate no bits set
 204  */
 205 static inline __attribute__((const))
 206 int ffs(int x)
 207 {
 208         /* Note: (x & -x) gives us a mask that is the least significant
 209          * (rightmost) 1-bit of the value in x.
 210          */
 211         return fls(x & -x);
 212 }
 213
 214 #include <asm-generic/bitops/ffz.h>
 215 #include <asm-generic/bitops/fls64.h>
 216 #include <asm-generic/bitops/find.h>
 217 #include <asm-generic/bitops/sched.h>
 218 #include <asm-generic/bitops/hweight.h>
 219
 220 #define ext2_set_bit_atomic(lock, nr, addr) \
 221         test_and_set_bit((nr) ^ 0x18, (addr))
 222 #define ext2_clear_bit_atomic(lock, nr, addr) \
 223         test_and_clear_bit((nr) ^ 0x18, (addr))
 224
 225 #include <asm-generic/bitops/ext2-non-atomic.h>
 226 #include <asm-generic/bitops/minix-le.h>
 227
 228 #endif /* __KERNEL__ */
 229 #endif /* __ASM_BITOPS_H */