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