release/src-rt-6.x/linux/linux-2.6/include/asm-xtensa/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 #include <asm/processor.h>
  19 #include <asm/byteorder.h>
  20 #include <asm/system.h>
  21
  22 #ifdef CONFIG_SMP
  23 # error SMP not supported on this architecture
  24 #endif
  25
  26 #define smp_mb__before_clear_bit()      barrier()
  27 #define smp_mb__after_clear_bit()       barrier()
  28
  29 #include <asm-generic/bitops/atomic.h>
  30 #include <asm-generic/bitops/non-atomic.h>
  31
  32 #if XCHAL_HAVE_NSA
  33
  34 static inline unsigned long __cntlz (unsigned long x)
  35 {
  36         int lz;
  37         asm ("nsau %0, %1" : "=r" (lz) : "r" (x));
  38         return lz;
  39 }
  40
  41 /*
  42  * ffz: Find first zero in word. Undefined if no zero exists.
  43  * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
  44  */
  45
  46 static inline int ffz(unsigned long x)
  47 {
  48         return 31 - __cntlz(~x & -~x);
  49 }
  50
  51 /*
  52  * __ffs: Find first bit set in word. Return 0 for bit 0
  53  */
  54
  55 static inline int __ffs(unsigned long x)
  56 {
  57         return 31 - __cntlz(x & -x);
  58 }
  59
  60 /*
  61  * ffs: Find first bit set in word. This is defined the same way as
  62  * the libc and compiler builtin ffs routines, therefore
  63  * differs in spirit from the above ffz (man ffs).
  64  */
  65
  66 static inline int ffs(unsigned long x)
  67 {
  68         return 32 - __cntlz(x & -x);
  69 }
  70
  71 /*
  72  * fls: Find last (most-significant) bit set in word.
  73  * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
  74  */
  75
  76 static inline int fls (unsigned int x)
  77 {
  78         return 32 - __cntlz(x);
  79 }
  80
  81 #else
  82
  83 /* Use the generic implementation if we don't have the nsa/nsau instructions. */
  84
  85 # include <asm-generic/bitops/ffs.h>
  86 # include <asm-generic/bitops/__ffs.h>
  87 # include <asm-generic/bitops/ffz.h>
  88 # include <asm-generic/bitops/fls.h>
  89
  90 #endif
  91
  92 #include <asm-generic/bitops/fls64.h>
  93 #include <asm-generic/bitops/find.h>
  94 #include <asm-generic/bitops/ext2-non-atomic.h>
  95
  96 #ifdef __XTENSA_EL__
  97 # define ext2_set_bit_atomic(lock,nr,addr)                              \
  98         test_and_set_bit((nr), (unsigned long*)(addr))
  99 # define ext2_clear_bit_atomic(lock,nr,addr)                            \
 100         test_and_clear_bit((nr), (unsigned long*)(addr))
 101 #elif defined(__XTENSA_EB__)
 102 # define ext2_set_bit_atomic(lock,nr,addr)                              \
 103         test_and_set_bit((nr) ^ 0x18, (unsigned long*)(addr))
 104 # define ext2_clear_bit_atomic(lock,nr,addr)                            \
 105         test_and_clear_bit((nr) ^ 0x18, (unsigned long*)(addr))
 106 #else
 107 # error processor byte order undefined!
 108 #endif
 109
 110 #include <asm-generic/bitops/hweight.h>
 111 #include <asm-generic/bitops/sched.h>
 112 #include <asm-generic/bitops/minix.h>
 113
 114 #endif  /* __KERNEL__ */
 115
 116 #endif  /* _XTENSA_BITOPS_H */