arch/xtensa/include/asm/bitops.h

   1 /*
   2  * include/asm-xtensa/bitops.h
   3  *
   4  * Atomic operations that C can't guarantee us.Useful for resource counting etc.
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License.  See the file "COPYING" in the main directory of this archive
   8  * for more details.
   9  *
  10  * Copyright (C) 2001 - 2007 Tensilica Inc.
  11  */
  12
  13 #ifndef _XTENSA_BITOPS_H
  14 #define _XTENSA_BITOPS_H
  15
  16 #ifdef __KERNEL__
  17
  18 #ifndef _LINUX_BITOPS_H
  19 #error only <linux/bitops.h> can be included directly
  20 #endif
  21
  22 #include <asm/processor.h>
  23 #include <asm/byteorder.h>
  24
  25 #define smp_mb__before_clear_bit()      smp_mb()
  26 #define smp_mb__after_clear_bit()       smp_mb()
  27
  28 #include <asm-generic/bitops/non-atomic.h>
  29
  30 #if XCHAL_HAVE_NSA
  31
  32 static inline unsigned long __cntlz (unsigned long x)
  33 {
  34         int lz;
  35         asm ("nsau %0, %1" : "=r" (lz) : "r" (x));
  36         return lz;
  37 }
  38
  39 /*
  40  * ffz: Find first zero in word. Undefined if no zero exists.
  41  * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
  42  */
  43
  44 static inline int ffz(unsigned long x)
  45 {
  46         return 31 - __cntlz(~x & -~x);
  47 }
  48
  49 /*
  50  * __ffs: Find first bit set in word. Return 0 for bit 0
  51  */
  52
  53 static inline int __ffs(unsigned long x)
  54 {
  55         return 31 - __cntlz(x & -x);
  56 }
  57
  58 /*
  59  * ffs: Find first bit set in word. This is defined the same way as
  60  * the libc and compiler builtin ffs routines, therefore
  61  * differs in spirit from the above ffz (man ffs).
  62  */
  63
  64 static inline int ffs(unsigned long x)
  65 {
  66         return 32 - __cntlz(x & -x);
  67 }
  68
  69 /*
  70  * fls: Find last (most-significant) bit set in word.
  71  * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
  72  */
  73
  74 static inline int fls (unsigned int x)
  75 {
  76         return 32 - __cntlz(x);
  77 }
  78
  79 /**
  80  * __fls - find last (most-significant) set bit in a long word
  81  * @word: the word to search
  82  *
  83  * Undefined if no set bit exists, so code should check against 0 first.
  84  */
  85 static inline unsigned long __fls(unsigned long word)
  86 {
  87         return 31 - __cntlz(word);
  88 }
  89 #else
  90
  91 /* Use the generic implementation if we don't have the nsa/nsau instructions. */
  92
  93 # include <asm-generic/bitops/ffs.h>
  94 # include <asm-generic/bitops/__ffs.h>
  95 # include <asm-generic/bitops/ffz.h>
  96 # include <asm-generic/bitops/fls.h>
  97 # include <asm-generic/bitops/__fls.h>
  98
  99 #endif
 100
 101 #include <asm-generic/bitops/fls64.h>
 102
 103 #if XCHAL_HAVE_S32C1I
 104
 105 static inline void set_bit(unsigned int bit, volatile unsigned long *p)
 106 {
 107         unsigned long tmp, value;
 108         unsigned long mask = 1UL << (bit & 31);
 109
 110         p += bit >> 5;
 111
 112         __asm__ __volatile__(
 113                         "1:     l32i    %1, %3, 0\n"
 114                         "       wsr     %1, scompare1\n"
 115                         "       or      %0, %1, %2\n"
 116                         "       s32c1i  %0, %3, 0\n"
 117                         "       bne     %0, %1, 1b\n"
 118                         : "=&a" (tmp), "=&a" (value)
 119                         : "a" (mask), "a" (p)
 120                         : "memory");
 121 }
 122
 123 static inline void clear_bit(unsigned int bit, volatile unsigned long *p)
 124 {
 125         unsigned long tmp, value;
 126         unsigned long mask = 1UL << (bit & 31);
 127
 128         p += bit >> 5;
 129
 130         __asm__ __volatile__(
 131                         "1:     l32i    %1, %3, 0\n"
 132                         "       wsr     %1, scompare1\n"
 133                         "       and     %0, %1, %2\n"
 134                         "       s32c1i  %0, %3, 0\n"
 135                         "       bne     %0, %1, 1b\n"
 136                         : "=&a" (tmp), "=&a" (value)
 137                         : "a" (~mask), "a" (p)
 138                         : "memory");
 139 }
 140
 141 static inline void change_bit(unsigned int bit, volatile unsigned long *p)
 142 {
 143         unsigned long tmp, value;
 144         unsigned long mask = 1UL << (bit & 31);
 145
 146         p += bit >> 5;
 147
 148         __asm__ __volatile__(
 149                         "1:     l32i    %1, %3, 0\n"
 150                         "       wsr     %1, scompare1\n"
 151                         "       xor     %0, %1, %2\n"
 152                         "       s32c1i  %0, %3, 0\n"
 153                         "       bne     %0, %1, 1b\n"
 154                         : "=&a" (tmp), "=&a" (value)
 155                         : "a" (mask), "a" (p)
 156                         : "memory");
 157 }
 158
 159 static inline int
 160 test_and_set_bit(unsigned int bit, volatile unsigned long *p)
 161 {
 162         unsigned long tmp, value;
 163         unsigned long mask = 1UL << (bit & 31);
 164
 165         p += bit >> 5;
 166
 167         __asm__ __volatile__(
 168                         "1:     l32i    %1, %3, 0\n"
 169                         "       wsr     %1, scompare1\n"
 170                         "       or      %0, %1, %2\n"
 171                         "       s32c1i  %0, %3, 0\n"
 172                         "       bne     %0, %1, 1b\n"
 173                         : "=&a" (tmp), "=&a" (value)
 174                         : "a" (mask), "a" (p)
 175                         : "memory");
 176
 177         return tmp & mask;
 178 }
 179
 180 static inline int
 181 test_and_clear_bit(unsigned int bit, volatile unsigned long *p)
 182 {
 183         unsigned long tmp, value;
 184         unsigned long mask = 1UL << (bit & 31);
 185
 186         p += bit >> 5;
 187
 188         __asm__ __volatile__(
 189                         "1:     l32i    %1, %3, 0\n"
 190                         "       wsr     %1, scompare1\n"
 191                         "       and     %0, %1, %2\n"
 192                         "       s32c1i  %0, %3, 0\n"
 193                         "       bne     %0, %1, 1b\n"
 194                         : "=&a" (tmp), "=&a" (value)
 195                         : "a" (~mask), "a" (p)
 196                         : "memory");
 197
 198         return tmp & mask;
 199 }
 200
 201 static inline int
 202 test_and_change_bit(unsigned int bit, volatile unsigned long *p)
 203 {
 204         unsigned long tmp, value;
 205         unsigned long mask = 1UL << (bit & 31);
 206
 207         p += bit >> 5;
 208
 209         __asm__ __volatile__(
 210                         "1:     l32i    %1, %3, 0\n"
 211                         "       wsr     %1, scompare1\n"
 212                         "       xor     %0, %1, %2\n"
 213                         "       s32c1i  %0, %3, 0\n"
 214                         "       bne     %0, %1, 1b\n"
 215                         : "=&a" (tmp), "=&a" (value)
 216                         : "a" (mask), "a" (p)
 217                         : "memory");
 218
 219         return tmp & mask;
 220 }
 221
 222 #else
 223
 224 #include <asm-generic/bitops/atomic.h>
 225
 226 #endif /* XCHAL_HAVE_S32C1I */
 227
 228 #include <asm-generic/bitops/find.h>
 229 #include <asm-generic/bitops/le.h>
 230
 231 #include <asm-generic/bitops/ext2-atomic-setbit.h>
 232
 233 #include <asm-generic/bitops/hweight.h>
 234 #include <asm-generic/bitops/lock.h>
 235 #include <asm-generic/bitops/sched.h>
 236
 237 #endif  /* __KERNEL__ */
 238
 239 #endif  /* _XTENSA_BITOPS_H */