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/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 #ifndef _LINUX_BITOPS_H
  25 #error only <linux/bitops.h> can be included directly
  26 #endif
  27
  28 #include <asm-generic/bitops/ffz.h>
  29
  30 /*
  31  * clear_bit() doesn't provide any barrier for the compiler.
  32  */
  33 #define smp_mb__before_clear_bit()      barrier()
  34 #define smp_mb__after_clear_bit()       barrier()
  35
  36 static inline int test_and_clear_bit(int nr, volatile void *addr)
  37 {
  38         volatile unsigned long *ptr = addr;
  39         unsigned long mask = 1UL << (nr & 31);
  40         ptr += nr >> 5;
  41         return (atomic_test_and_ANDNOT_mask(mask, ptr) & mask) != 0;
  42 }
  43
  44 static inline int test_and_set_bit(int nr, volatile void *addr)
  45 {
  46         volatile unsigned long *ptr = addr;
  47         unsigned long mask = 1UL << (nr & 31);
  48         ptr += nr >> 5;
  49         return (atomic_test_and_OR_mask(mask, ptr) & mask) != 0;
  50 }
  51
  52 static inline int test_and_change_bit(int nr, volatile void *addr)
  53 {
  54         volatile unsigned long *ptr = addr;
  55         unsigned long mask = 1UL << (nr & 31);
  56         ptr += nr >> 5;
  57         return (atomic_test_and_XOR_mask(mask, ptr) & mask) != 0;
  58 }
  59
  60 static inline void clear_bit(int nr, volatile void *addr)
  61 {
  62         test_and_clear_bit(nr, addr);
  63 }
  64
  65 static inline void set_bit(int nr, volatile void *addr)
  66 {
  67         test_and_set_bit(nr, addr);
  68 }
  69
  70 static inline void change_bit(int nr, volatile void * addr)
  71 {
  72         test_and_change_bit(nr, addr);
  73 }
  74
  75 static inline void __clear_bit(int nr, volatile void * addr)
  76 {
  77         volatile unsigned long *a = addr;
  78         int mask;
  79
  80         a += nr >> 5;
  81         mask = 1 << (nr & 31);
  82         *a &= ~mask;
  83 }
  84
  85 static inline void __set_bit(int nr, volatile void * addr)
  86 {
  87         volatile unsigned long *a = addr;
  88         int mask;
  89
  90         a += nr >> 5;
  91         mask = 1 << (nr & 31);
  92         *a |= mask;
  93 }
  94
  95 static inline void __change_bit(int nr, volatile void *addr)
  96 {
  97         volatile unsigned long *a = addr;
  98         int mask;
  99
 100         a += nr >> 5;
 101         mask = 1 << (nr & 31);
 102         *a ^= mask;
 103 }
 104
 105 static inline int __test_and_clear_bit(int nr, volatile void * addr)
 106 {
 107         volatile unsigned long *a = addr;
 108         int mask, retval;
 109
 110         a += nr >> 5;
 111         mask = 1 << (nr & 31);
 112         retval = (mask & *a) != 0;
 113         *a &= ~mask;
 114         return retval;
 115 }
 116
 117 static inline int __test_and_set_bit(int nr, volatile void * addr)
 118 {
 119         volatile unsigned long *a = addr;
 120         int mask, retval;
 121
 122         a += nr >> 5;
 123         mask = 1 << (nr & 31);
 124         retval = (mask & *a) != 0;
 125         *a |= mask;
 126         return retval;
 127 }
 128
 129 static inline int __test_and_change_bit(int nr, volatile void * addr)
 130 {
 131         volatile unsigned long *a = addr;
 132         int mask, retval;
 133
 134         a += nr >> 5;
 135         mask = 1 << (nr & 31);
 136         retval = (mask & *a) != 0;
 137         *a ^= mask;
 138         return retval;
 139 }
 140
 141 /*
 142  * This routine doesn't need to be atomic.
 143  */
 144 static inline int __constant_test_bit(int nr, const volatile void * addr)
 145 {
 146         return ((1UL << (nr & 31)) & (((const volatile unsigned int *) addr)[nr >> 5])) != 0;
 147 }
 148
 149 static inline int __test_bit(int nr, const volatile void * addr)
 150 {
 151         int     * a = (int *) addr;
 152         int     mask;
 153
 154         a += nr >> 5;
 155         mask = 1 << (nr & 0x1f);
 156         return ((mask & *a) != 0);
 157 }
 158
 159 #define test_bit(nr,addr) \
 160 (__builtin_constant_p(nr) ? \
 161  __constant_test_bit((nr),(addr)) : \
 162  __test_bit((nr),(addr)))
 163
 164 #include <asm-generic/bitops/find.h>
 165
 166 /**
 167  * fls - find last bit set
 168  * @x: the word to search
 169  *
 170  * This is defined the same way as ffs:
 171  * - return 32..1 to indicate bit 31..0 most significant bit set
 172  * - return 0 to indicate no bits set
 173  */
 174 #define fls(x)                                          \
 175 ({                                                      \
 176         int bit;                                        \
 177                                                         \
 178         asm("   subcc   %1,gr0,gr0,icc0         \n"     \
 179             "   ckne    icc0,cc4                \n"     \
 180             "   cscan.p %1,gr0,%0       ,cc4,#1 \n"     \
 181             "   csub    %0,%0,%0        ,cc4,#0 \n"     \
 182             "   csub    %2,%0,%0        ,cc4,#1 \n"     \
 183             : "=&r"(bit)                                \
 184             : "r"(x), "r"(32)                           \
 185             : "icc0", "cc4"                             \
 186             );                                          \
 187                                                         \
 188         bit;                                            \
 189 })
 190
 191 /**
 192  * fls64 - find last bit set in a 64-bit value
 193  * @n: the value to search
 194  *
 195  * This is defined the same way as ffs:
 196  * - return 64..1 to indicate bit 63..0 most significant bit set
 197  * - return 0 to indicate no bits set
 198  */
 199 static inline __attribute__((const))
 200 int fls64(u64 n)
 201 {
 202         union {
 203                 u64 ll;
 204                 struct { u32 h, l; };
 205         } _;
 206         int bit, x, y;
 207
 208         _.ll = n;
 209
 210         asm("   subcc.p         %3,gr0,gr0,icc0         \n"
 211             "   subcc           %4,gr0,gr0,icc1         \n"
 212             "   ckne            icc0,cc4                \n"
 213             "   ckne            icc1,cc5                \n"
 214             "   norcr           cc4,cc5,cc6             \n"
 215             "   csub.p          %0,%0,%0        ,cc6,1  \n"
 216             "   orcr            cc5,cc4,cc4             \n"
 217             "   andcr           cc4,cc5,cc4             \n"
 218             "   cscan.p         %3,gr0,%0       ,cc4,0  \n"
 219             "   setlos          #64,%1                  \n"
 220             "   cscan.p         %4,gr0,%0       ,cc4,1  \n"
 221             "   setlos          #32,%2                  \n"
 222             "   csub.p          %1,%0,%0        ,cc4,0  \n"
 223             "   csub            %2,%0,%0        ,cc4,1  \n"
 224             : "=&r"(bit), "=r"(x), "=r"(y)
 225             : "0r"(_.h), "r"(_.l)
 226             : "icc0", "icc1", "cc4", "cc5", "cc6"
 227             );
 228         return bit;
 229
 230 }
 231
 232 /**
 233  * ffs - find first bit set
 234  * @x: the word to search
 235  *
 236  * - return 32..1 to indicate bit 31..0 most least significant bit set
 237  * - return 0 to indicate no bits set
 238  */
 239 static inline __attribute__((const))
 240 int ffs(int x)
 241 {
 242         /* Note: (x & -x) gives us a mask that is the least significant
 243          * (rightmost) 1-bit of the value in x.
 244          */
 245         return fls(x & -x);
 246 }
 247
 248 /**
 249  * __ffs - find first bit set
 250  * @x: the word to search
 251  *
 252  * - return 31..0 to indicate bit 31..0 most least significant bit set
 253  * - if no bits are set in x, the result is undefined
 254  */
 255 static inline __attribute__((const))
 256 int __ffs(unsigned long x)
 257 {
 258         int bit;
 259         asm("scan %1,gr0,%0" : "=r"(bit) : "r"(x & -x));
 260         return 31 - bit;
 261 }
 262
 263 /*
 264  * special slimline version of fls() for calculating ilog2_u32()
 265  * - note: no protection against n == 0
 266  */
 267 #define ARCH_HAS_ILOG2_U32
 268 static inline __attribute__((const))
 269 int __ilog2_u32(u32 n)
 270 {
 271         int bit;
 272         asm("scan %1,gr0,%0" : "=r"(bit) : "r"(n));
 273         return 31 - bit;
 274 }
 275
 276 /*
 277  * special slimline version of fls64() for calculating ilog2_u64()
 278  * - note: no protection against n == 0
 279  */
 280 #define ARCH_HAS_ILOG2_U64
 281 static inline __attribute__((const))
 282 int __ilog2_u64(u64 n)
 283 {
 284         union {
 285                 u64 ll;
 286                 struct { u32 h, l; };
 287         } _;
 288         int bit, x, y;
 289
 290         _.ll = n;
 291
 292         asm("   subcc           %3,gr0,gr0,icc0         \n"
 293             "   ckeq            icc0,cc4                \n"
 294             "   cscan.p         %3,gr0,%0       ,cc4,0  \n"
 295             "   setlos          #63,%1                  \n"
 296             "   cscan.p         %4,gr0,%0       ,cc4,1  \n"
 297             "   setlos          #31,%2                  \n"
 298             "   csub.p          %1,%0,%0        ,cc4,0  \n"
 299             "   csub            %2,%0,%0        ,cc4,1  \n"
 300             : "=&r"(bit), "=r"(x), "=r"(y)
 301             : "0r"(_.h), "r"(_.l)
 302             : "icc0", "cc4"
 303             );
 304         return bit;
 305 }
 306
 307 #include <asm-generic/bitops/sched.h>
 308 #include <asm-generic/bitops/hweight.h>
 309 #include <asm-generic/bitops/lock.h>
 310
 311 #include <asm-generic/bitops/ext2-non-atomic.h>
 312
 313 #define ext2_set_bit_atomic(lock,nr,addr)       test_and_set_bit  ((nr) ^ 0x18, (addr))
 314 #define ext2_clear_bit_atomic(lock,nr,addr)     test_and_clear_bit((nr) ^ 0x18, (addr))
 315
 316 #include <asm-generic/bitops/minix-le.h>
 317
 318 #endif /* __KERNEL__ */
 319
 320 #endif /* _ASM_BITOPS_H */