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 #ifndef _LINUX_BITOPS_H 19 #error only <linux/bitops.h> can be included directly 20 #endif 21 22 #include <asm/processor.h> 23 #include <asm/byteorder.h> 24 #include <asm/system.h> 25 26 #ifdef CONFIG_SMP 27 # error SMP not supported on this architecture 28 #endif 29 30 #define smp_mb__before_clear_bit() barrier() 31 #define smp_mb__after_clear_bit() barrier() 32 33 #include <asm-generic/bitops/atomic.h> 34 #include <asm-generic/bitops/non-atomic.h> 35 36 #if XCHAL_HAVE_NSA 37 38 static inline unsigned long __cntlz (unsigned long x) 39 { 40 int lz; 41 asm ("nsau %0, %1" : "=r" (lz) : "r" (x)); 42 return lz; 43 } 44 45 /* 46 * ffz: Find first zero in word. Undefined if no zero exists. 47 * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1). 48 */ 49 50 static inline int ffz(unsigned long x) 51 { 52 return 31 - __cntlz(~x & -~x); 53 } 54 55 /* 56 * __ffs: Find first bit set in word. Return 0 for bit 0 57 */ 58 59 static inline int __ffs(unsigned long x) 60 { 61 return 31 - __cntlz(x & -x); 62 } 63 64 /* 65 * ffs: Find first bit set in word. This is defined the same way as 66 * the libc and compiler builtin ffs routines, therefore 67 * differs in spirit from the above ffz (man ffs). 68 */ 69 70 static inline int ffs(unsigned long x) 71 { 72 return 32 - __cntlz(x & -x); 73 } 74 75 /* 76 * fls: Find last (most-significant) bit set in word. 77 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. 78 */ 79 80 static inline int fls (unsigned int x) 81 { 82 return 32 - __cntlz(x); 83 } 84 85 /** 86 * __fls - find last (most-significant) set bit in a long word 87 * @word: the word to search 88 * 89 * Undefined if no set bit exists, so code should check against 0 first. 90 */ 91 static inline unsigned long __fls(unsigned long word) 92 { 93 return 31 - __cntlz(word); 94 } 95 #else 96 97 /* Use the generic implementation if we don't have the nsa/nsau instructions. */ 98 99 # include <asm-generic/bitops/ffs.h> 100 # include <asm-generic/bitops/__ffs.h> 101 # include <asm-generic/bitops/ffz.h> 102 # include <asm-generic/bitops/fls.h> 103 # include <asm-generic/bitops/__fls.h> 104 105 #endif 106 107 #include <asm-generic/bitops/fls64.h> 108 #include <asm-generic/bitops/find.h> 109 #include <asm-generic/bitops/ext2-non-atomic.h> 110 111 #ifdef __XTENSA_EL__ 112 # define ext2_set_bit_atomic(lock,nr,addr) \ 113 test_and_set_bit((nr), (unsigned long*)(addr)) 114 # define ext2_clear_bit_atomic(lock,nr,addr) \ 115 test_and_clear_bit((nr), (unsigned long*)(addr)) 116 #elif defined(__XTENSA_EB__) 117 # define ext2_set_bit_atomic(lock,nr,addr) \ 118 test_and_set_bit((nr) ^ 0x18, (unsigned long*)(addr)) 119 # define ext2_clear_bit_atomic(lock,nr,addr) \ 120 test_and_clear_bit((nr) ^ 0x18, (unsigned long*)(addr)) 121 #else 122 # error processor byte order undefined! 123 #endif 124 125 #include <asm-generic/bitops/hweight.h> 126 #include <asm-generic/bitops/lock.h> 127 #include <asm-generic/bitops/sched.h> 128 #include <asm-generic/bitops/minix.h> 129 130 #endif /* __KERNEL__ */ 131 132 #endif /* _XTENSA_BITOPS_H */ 133