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