include/asm-frv/bitops.h

   1 /* bitops.h: bit operations for the Fujitsu FR-V CPUs
   2  *
   3  * For an explanation of how atomic ops work in this arch, see:
   4  *   Documentation/fujitsu/frv/atomic-ops.txt
   5  *
   6  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
   7  * Written by David Howells (dhowells@redhat.com)
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License
  11  * as published by the Free Software Foundation; either version
  12  * 2 of the License, or (at your option) any later version.
  13  */
  14 #ifndef _ASM_BITOPS_H
  15 #define _ASM_BITOPS_H
  16
  17 #include <linux/compiler.h>
  18 #include <asm/byteorder.h>
  19 #include <asm/system.h>
  20 #include <asm/atomic.h>
  21
  22 #ifdef __KERNEL__
  23
  24 #include <asm-generic/bitops/ffz.h>
  25
  26 /*
  27  * clear_bit() doesn't provide any barrier for the compiler.
  28  */
  29 #define smp_mb__before_clear_bit()      barrier()
  30 #define smp_mb__after_clear_bit()       barrier()
  31
  32 static inline int test_and_clear_bit(int nr, volatile void *addr)
  33 {
  34         volatile unsigned long *ptr = addr;
  35         unsigned long mask = 1UL << (nr & 31);
  36         ptr += nr >> 5;
  37         return (atomic_test_and_ANDNOT_mask(mask, ptr) & mask) != 0;
  38 }
  39
  40 static inline int test_and_set_bit(int nr, volatile void *addr)
  41 {
  42         volatile unsigned long *ptr = addr;
  43         unsigned long mask = 1UL << (nr & 31);
  44         ptr += nr >> 5;
  45         return (atomic_test_and_OR_mask(mask, ptr) & mask) != 0;
  46 }
  47
  48 static inline int test_and_change_bit(int nr, volatile void *addr)
  49 {
  50         volatile unsigned long *ptr = addr;
  51         unsigned long mask = 1UL << (nr & 31);
  52         ptr += nr >> 5;
  53         return (atomic_test_and_XOR_mask(mask, ptr) & mask) != 0;
  54 }
  55
  56 static inline void clear_bit(int nr, volatile void *addr)
  57 {
  58         test_and_clear_bit(nr, addr);
  59 }
  60
  61 static inline void set_bit(int nr, volatile void *addr)
  62 {
  63         test_and_set_bit(nr, addr);
  64 }
  65
  66 static inline void change_bit(int nr, volatile void * addr)
  67 {
  68         test_and_change_bit(nr, addr);
  69 }
  70
  71 static inline void __clear_bit(int nr, volatile void * addr)
  72 {
  73         volatile unsigned long *a = addr;
  74         int mask;
  75
  76         a += nr >> 5;
  77         mask = 1 << (nr & 31);
  78         *a &= ~mask;
  79 }
  80
  81 static inline void __set_bit(int nr, volatile void * addr)
  82 {
  83         volatile unsigned long *a = addr;
  84         int mask;
  85
  86         a += nr >> 5;
  87         mask = 1 << (nr & 31);
  88         *a |= mask;
  89 }
  90
  91 static inline void __change_bit(int nr, volatile void *addr)
  92 {
  93         volatile unsigned long *a = addr;
  94         int mask;
  95
  96         a += nr >> 5;
  97         mask = 1 << (nr & 31);
  98         *a ^= mask;
  99 }
 100
 101 static inline int __test_and_clear_bit(int nr, volatile void * addr)
 102 {
 103         volatile unsigned long *a = addr;
 104         int mask, retval;
 105
 106         a += nr >> 5;
 107         mask = 1 << (nr & 31);
 108         retval = (mask & *a) != 0;
 109         *a &= ~mask;
 110         return retval;
 111 }
 112
 113 static inline int __test_and_set_bit(int nr, volatile void * addr)
 114 {
 115         volatile unsigned long *a = addr;
 116         int mask, retval;
 117
 118         a += nr >> 5;
 119         mask = 1 << (nr & 31);
 120         retval = (mask & *a) != 0;
 121         *a |= mask;
 122         return retval;
 123 }
 124
 125 static inline int __test_and_change_bit(int nr, volatile void * addr)
 126 {
 127         volatile unsigned long *a = addr;
 128         int mask, retval;
 129
 130         a += nr >> 5;
 131         mask = 1 << (nr & 31);
 132         retval = (mask & *a) != 0;
 133         *a ^= mask;
 134         return retval;
 135 }
 136
 137 /*
 138  * This routine doesn't need to be atomic.
 139  */
 140 static inline int __constant_test_bit(int nr, const volatile void * addr)
 141 {
 142         return ((1UL << (nr & 31)) & (((const volatile unsigned int *) addr)[nr >> 5])) != 0;
 143 }
 144
 145 static inline int __test_bit(int nr, const volatile void * addr)
 146 {
 147         int     * a = (int *) addr;
 148         int     mask;
 149
 150         a += nr >> 5;
 151         mask = 1 << (nr & 0x1f);
 152         return ((mask & *a) != 0);
 153 }
 154
 155 #define test_bit(nr,addr) \
 156 (__builtin_constant_p(nr) ? \
 157  __constant_test_bit((nr),(addr)) : \
 158  __test_bit((nr),(addr)))
 159
 160 #include <asm-generic/bitops/find.h>
 161
 162 /**
 163  * fls - find last bit set
 164  * @x: the word to search
 165  *
 166  * This is defined the same way as ffs:
 167  * - return 32..1 to indicate bit 31..0 most significant bit set
 168  * - return 0 to indicate no bits set
 169  */
 170 #define fls(x)                                          \
 171 ({                                                      \
 172         int bit;                                        \
 173                                                         \
 174         asm("   subcc   %1,gr0,gr0,icc0         \n"     \
 175             "   ckne    icc0,cc4                \n"     \
 176             "   cscan.p %1,gr0,%0       ,cc4,#1 \n"     \
 177             "   csub    %0,%0,%0        ,cc4,#0 \n"     \
 178             "   csub    %2,%0,%0        ,cc4,#1 \n"     \
 179             : "=&r"(bit)                                \
 180             : "r"(x), "r"(32)                           \
 181             : "icc0", "cc4"                             \
 182             );                                          \
 183                                                         \
 184         bit;                                            \
 185 })
 186
 187 /**
 188  * fls64 - find last bit set in a 64-bit value
 189  * @n: the value to search
 190  *
 191  * This is defined the same way as ffs:
 192  * - return 64..1 to indicate bit 63..0 most significant bit set
 193  * - return 0 to indicate no bits set
 194  */
 195 static inline __attribute__((const))
 196 int fls64(u64 n)
 197 {
 198         union {
 199                 u64 ll;
 200                 struct { u32 h, l; };
 201         } _;
 202         int bit, x, y;
 203
 204         _.ll = n;
 205
 206         asm("   subcc.p         %3,gr0,gr0,icc0         \n"
 207             "   subcc           %4,gr0,gr0,icc1         \n"
 208             "   ckne            icc0,cc4                \n"
 209             "   ckne            icc1,cc5                \n"
 210             "   norcr           cc4,cc5,cc6             \n"
 211             "   csub.p          %0,%0,%0        ,cc6,1  \n"
 212             "   orcr            cc5,cc4,cc4             \n"
 213             "   andcr           cc4,cc5,cc4             \n"
 214             "   cscan.p         %3,gr0,%0       ,cc4,0  \n"
 215             "   setlos          #64,%1                  \n"
 216             "   cscan.p         %4,gr0,%0       ,cc4,1  \n"
 217             "   setlos          #32,%2                  \n"
 218             "   csub.p          %1,%0,%0        ,cc4,0  \n"
 219             "   csub            %2,%0,%0        ,cc4,1  \n"
 220             : "=&r"(bit), "=r"(x), "=r"(y)
 221             : "0r"(_.h), "r"(_.l)
 222             : "icc0", "icc1", "cc4", "cc5", "cc6"
 223             );
 224         return bit;
 225
 226 }
 227
 228 /**
 229  * ffs - find first bit set
 230  * @x: the word to search
 231  *
 232  * - return 32..1 to indicate bit 31..0 most least significant bit set
 233  * - return 0 to indicate no bits set
 234  */
 235 static inline __attribute__((const))
 236 int ffs(int x)
 237 {
 238         /* Note: (x & -x) gives us a mask that is the least significant
 239          * (rightmost) 1-bit of the value in x.
 240          */
 241         return fls(x & -x);
 242 }
 243
 244 /**
 245  * __ffs - find first bit set
 246  * @x: the word to search
 247  *
 248  * - return 31..0 to indicate bit 31..0 most least significant bit set
 249  * - if no bits are set in x, the result is undefined
 250  */
 251 static inline __attribute__((const))
 252 int __ffs(unsigned long x)
 253 {
 254         int bit;
 255         asm("scan %1,gr0,%0" : "=r"(bit) : "r"(x & -x));
 256         return 31 - bit;
 257 }
 258
 259 /*
 260  * special slimline version of fls() for calculating ilog2_u32()
 261  * - note: no protection against n == 0
 262  */
 263 #define ARCH_HAS_ILOG2_U32
 264 static inline __attribute__((const))
 265 int __ilog2_u32(u32 n)
 266 {
 267         int bit;
 268         asm("scan %1,gr0,%0" : "=r"(bit) : "r"(n));
 269         return 31 - bit;
 270 }
 271
 272 /*
 273  * special slimline version of fls64() for calculating ilog2_u64()
 274  * - note: no protection against n == 0
 275  */
 276 #define ARCH_HAS_ILOG2_U64
 277 static inline __attribute__((const))
 278 int __ilog2_u64(u64 n)
 279 {
 280         union {
 281                 u64 ll;
 282                 struct { u32 h, l; };
 283         } _;
 284         int bit, x, y;
 285
 286         _.ll = n;
 287
 288         asm("   subcc           %3,gr0,gr0,icc0         \n"
 289             "   ckeq            icc0,cc4                \n"
 290             "   cscan.p         %3,gr0,%0       ,cc4,0  \n"
 291             "   setlos          #63,%1                  \n"
 292             "   cscan.p         %4,gr0,%0       ,cc4,1  \n"
 293             "   setlos          #31,%2                  \n"
 294             "   csub.p          %1,%0,%0        ,cc4,0  \n"
 295             "   csub            %2,%0,%0        ,cc4,1  \n"
 296             : "=&r"(bit), "=r"(x), "=r"(y)
 297             : "0r"(_.h), "r"(_.l)
 298             : "icc0", "cc4"
 299             );
 300         return bit;
 301 }
 302
 303 #include <asm-generic/bitops/sched.h>
 304 #include <asm-generic/bitops/hweight.h>
 305
 306 #include <asm-generic/bitops/ext2-non-atomic.h>
 307
 308 #define ext2_set_bit_atomic(lock,nr,addr)       test_and_set_bit  ((nr) ^ 0x18, (addr))
 309 #define ext2_clear_bit_atomic(lock,nr,addr)     test_and_clear_bit((nr) ^ 0x18, (addr))
 310
 311 #include <asm-generic/bitops/minix-le.h>
 312
 313 #endif /* __KERNEL__ */
 314
 315 #endif /* _ASM_BITOPS_H */