arch/parisc/include/asm/bitops.h

   1 #ifndef _PARISC_BITOPS_H
   2 #define _PARISC_BITOPS_H
   3
   4 #ifndef _LINUX_BITOPS_H
   5 #error only <linux/bitops.h> can be included directly
   6 #endif
   7
   8 #include <linux/compiler.h>
   9 #include <asm/types.h>          /* for BITS_PER_LONG/SHIFT_PER_LONG */
  10 #include <asm/byteorder.h>
  11 #include <linux/atomic.h>
  12
  13 /*
  14  * HP-PARISC specific bit operations
  15  * for a detailed description of the functions please refer
  16  * to include/asm-i386/bitops.h or kerneldoc
  17  */
  18
  19 #define CHOP_SHIFTCOUNT(x) (((unsigned long) (x)) & (BITS_PER_LONG - 1))
  20
  21
  22 #define smp_mb__before_clear_bit()      smp_mb()
  23 #define smp_mb__after_clear_bit()       smp_mb()
  24
  25 /* See http://marc.theaimsgroup.com/?t=108826637900003 for discussion
  26  * on use of volatile and __*_bit() (set/clear/change):
  27  *      *_bit() want use of volatile.
  28  *      __*_bit() are "relaxed" and don't use spinlock or volatile.
  29  */
  30
  31 static __inline__ void set_bit(int nr, volatile unsigned long * addr)
  32 {
  33         unsigned long mask = 1UL << CHOP_SHIFTCOUNT(nr);
  34         unsigned long flags;
  35
  36         addr += (nr >> SHIFT_PER_LONG);
  37         _atomic_spin_lock_irqsave(addr, flags);
  38         *addr |= mask;
  39         _atomic_spin_unlock_irqrestore(addr, flags);
  40 }
  41
  42 static __inline__ void clear_bit(int nr, volatile unsigned long * addr)
  43 {
  44         unsigned long mask = ~(1UL << CHOP_SHIFTCOUNT(nr));
  45         unsigned long flags;
  46
  47         addr += (nr >> SHIFT_PER_LONG);
  48         _atomic_spin_lock_irqsave(addr, flags);
  49         *addr &= mask;
  50         _atomic_spin_unlock_irqrestore(addr, flags);
  51 }
  52
  53 static __inline__ void change_bit(int nr, volatile unsigned long * addr)
  54 {
  55         unsigned long mask = 1UL << CHOP_SHIFTCOUNT(nr);
  56         unsigned long flags;
  57
  58         addr += (nr >> SHIFT_PER_LONG);
  59         _atomic_spin_lock_irqsave(addr, flags);
  60         *addr ^= mask;
  61         _atomic_spin_unlock_irqrestore(addr, flags);
  62 }
  63
  64 static __inline__ int test_and_set_bit(int nr, volatile unsigned long * addr)
  65 {
  66         unsigned long mask = 1UL << CHOP_SHIFTCOUNT(nr);
  67         unsigned long old;
  68         unsigned long flags;
  69         int set;
  70
  71         addr += (nr >> SHIFT_PER_LONG);
  72         _atomic_spin_lock_irqsave(addr, flags);
  73         old = *addr;
  74         set = (old & mask) ? 1 : 0;
  75         if (!set)
  76                 *addr = old | mask;
  77         _atomic_spin_unlock_irqrestore(addr, flags);
  78
  79         return set;
  80 }
  81
  82 static __inline__ int test_and_clear_bit(int nr, volatile unsigned long * addr)
  83 {
  84         unsigned long mask = 1UL << CHOP_SHIFTCOUNT(nr);
  85         unsigned long old;
  86         unsigned long flags;
  87         int set;
  88
  89         addr += (nr >> SHIFT_PER_LONG);
  90         _atomic_spin_lock_irqsave(addr, flags);
  91         old = *addr;
  92         set = (old & mask) ? 1 : 0;
  93         if (set)
  94                 *addr = old & ~mask;
  95         _atomic_spin_unlock_irqrestore(addr, flags);
  96
  97         return set;
  98 }
  99
 100 static __inline__ int test_and_change_bit(int nr, volatile unsigned long * addr)
 101 {
 102         unsigned long mask = 1UL << CHOP_SHIFTCOUNT(nr);
 103         unsigned long oldbit;
 104         unsigned long flags;
 105
 106         addr += (nr >> SHIFT_PER_LONG);
 107         _atomic_spin_lock_irqsave(addr, flags);
 108         oldbit = *addr;
 109         *addr = oldbit ^ mask;
 110         _atomic_spin_unlock_irqrestore(addr, flags);
 111
 112         return (oldbit & mask) ? 1 : 0;
 113 }
 114
 115 #include <asm-generic/bitops/non-atomic.h>
 116
 117 #ifdef __KERNEL__
 118
 119 /**
 120  * __ffs - find first bit in word. returns 0 to "BITS_PER_LONG-1".
 121  * @word: The word to search
 122  *
 123  * __ffs() return is undefined if no bit is set.
 124  *
 125  * 32-bit fast __ffs by LaMont Jones "lamont At hp com".
 126  * 64-bit enhancement by Grant Grundler "grundler At parisc-linux org".
 127  * (with help from willy/jejb to get the semantics right)
 128  *
 129  * This algorithm avoids branches by making use of nullification.
 130  * One side effect of "extr" instructions is it sets PSW[N] bit.
 131  * How PSW[N] (nullify next insn) gets set is determined by the
 132  * "condition" field (eg "<>" or "TR" below) in the extr* insn.
 133  * Only the 1st and one of either the 2cd or 3rd insn will get executed.
 134  * Each set of 3 insn will get executed in 2 cycles on PA8x00 vs 16 or so
 135  * cycles for each mispredicted branch.
 136  */
 137
 138 static __inline__ unsigned long __ffs(unsigned long x)
 139 {
 140         unsigned long ret;
 141
 142         __asm__(
 143 #ifdef CONFIG_64BIT
 144                 " ldi       63,%1\n"
 145                 " extrd,u,*<>  %0,63,32,%%r0\n"
 146                 " extrd,u,*TR  %0,31,32,%0\n"   /* move top 32-bits down */
 147                 " addi    -32,%1,%1\n"
 148 #else
 149                 " ldi       31,%1\n"
 150 #endif
 151                 " extru,<>  %0,31,16,%%r0\n"
 152                 " extru,TR  %0,15,16,%0\n"      /* xxxx0000 -> 0000xxxx */
 153                 " addi    -16,%1,%1\n"
 154                 " extru,<>  %0,31,8,%%r0\n"
 155                 " extru,TR  %0,23,8,%0\n"       /* 0000xx00 -> 000000xx */
 156                 " addi    -8,%1,%1\n"
 157                 " extru,<>  %0,31,4,%%r0\n"
 158                 " extru,TR  %0,27,4,%0\n"       /* 000000x0 -> 0000000x */
 159                 " addi    -4,%1,%1\n"
 160                 " extru,<>  %0,31,2,%%r0\n"
 161                 " extru,TR  %0,29,2,%0\n"       /* 0000000y, 1100b -> 0011b */
 162                 " addi    -2,%1,%1\n"
 163                 " extru,=  %0,31,1,%%r0\n"      /* check last bit */
 164                 " addi    -1,%1,%1\n"
 165                         : "+r" (x), "=r" (ret) );
 166         return ret;
 167 }
 168
 169 #include <asm-generic/bitops/ffz.h>
 170
 171 /*
 172  * ffs: find first bit set. returns 1 to BITS_PER_LONG or 0 (if none set)
 173  * This is defined the same way as the libc and compiler builtin
 174  * ffs routines, therefore differs in spirit from the above ffz (man ffs).
 175  */
 176 static __inline__ int ffs(int x)
 177 {
 178         return x ? (__ffs((unsigned long)x) + 1) : 0;
 179 }
 180
 181 /*
 182  * fls: find last (most significant) bit set.
 183  * fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
 184  */
 185
 186 static __inline__ int fls(int x)
 187 {
 188         int ret;
 189         if (!x)
 190                 return 0;
 191
 192         __asm__(
 193         "       ldi             1,%1\n"
 194         "       extru,<>        %0,15,16,%%r0\n"
 195         "       zdep,TR         %0,15,16,%0\n"          /* xxxx0000 */
 196         "       addi            16,%1,%1\n"
 197         "       extru,<>        %0,7,8,%%r0\n"
 198         "       zdep,TR         %0,23,24,%0\n"          /* xx000000 */
 199         "       addi            8,%1,%1\n"
 200         "       extru,<>        %0,3,4,%%r0\n"
 201         "       zdep,TR         %0,27,28,%0\n"          /* x0000000 */
 202         "       addi            4,%1,%1\n"
 203         "       extru,<>        %0,1,2,%%r0\n"
 204         "       zdep,TR         %0,29,30,%0\n"          /* y0000000 (y&3 = 0) */
 205         "       addi            2,%1,%1\n"
 206         "       extru,=         %0,0,1,%%r0\n"
 207         "       addi            1,%1,%1\n"              /* if y & 8, add 1 */
 208                 : "+r" (x), "=r" (ret) );
 209
 210         return ret;
 211 }
 212
 213 #include <asm-generic/bitops/__fls.h>
 214 #include <asm-generic/bitops/fls64.h>
 215 #include <asm-generic/bitops/hweight.h>
 216 #include <asm-generic/bitops/lock.h>
 217 #include <asm-generic/bitops/sched.h>
 218
 219 #endif /* __KERNEL__ */
 220
 221 #include <asm-generic/bitops/find.h>
 222
 223 #ifdef __KERNEL__
 224
 225 #include <asm-generic/bitops/le.h>
 226 #include <asm-generic/bitops/ext2-atomic-setbit.h>
 227
 228 #endif  /* __KERNEL__ */
 229
 230 #endif /* _PARISC_BITOPS_H */