1 #ifndef _LINUX_BITOPS_H
2 #define _LINUX_BITOPS_H
3
4 #include <asm/types.h>
5 #include <asm-generic/bitsperlong.h>
6 #include <linux/compiler.h>
7
8 #ifdef __KERNEL__
9 #define BIT(nr) (1UL << (nr))
10 #define BIT_ULL(nr) (1ULL << (nr))
11 #define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
12 #define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
13 #define BIT_ULL_MASK(nr) (1ULL << ((nr) % BITS_PER_LONG_LONG))
14 #define BIT_ULL_WORD(nr) ((nr) / BITS_PER_LONG_LONG)
15 #define BITS_PER_BYTE 8
16 #define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
17 #endif
18
19 /*
20 * Create a contiguous bitmask starting at bit position @l and ending at
21 * position @h. For example
22 * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
23 */
24 #define GENMASK(h, l) \
25 (((~0UL) << (l)) & (~0UL >> (BITS_PER_LONG - 1 - (h))))
26
27 #define GENMASK_ULL(h, l) \
28 (((~0ULL) << (l)) & (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h))))
29
30 /*
31 * ffs: find first bit set. This is defined the same way as
32 * the libc and compiler builtin ffs routines, therefore
33 * differs in spirit from the above ffz (man ffs).
34 */
35
generic_ffs(int x)36 static inline int generic_ffs(int x)
37 {
38 int r = 1;
39
40 if (!x)
41 return 0;
42 if (!(x & 0xffff)) {
43 x >>= 16;
44 r += 16;
45 }
46 if (!(x & 0xff)) {
47 x >>= 8;
48 r += 8;
49 }
50 if (!(x & 0xf)) {
51 x >>= 4;
52 r += 4;
53 }
54 if (!(x & 3)) {
55 x >>= 2;
56 r += 2;
57 }
58 if (!(x & 1)) {
59 x >>= 1;
60 r += 1;
61 }
62 return r;
63 }
64
65 /**
66 * fls - find last (most-significant) bit set
67 * @x: the word to search
68 *
69 * This is defined the same way as ffs.
70 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
71 */
generic_fls(int x)72 static inline int generic_fls(int x)
73 {
74 int r = 32;
75
76 if (!x)
77 return 0;
78 if (!(x & 0xffff0000u)) {
79 x <<= 16;
80 r -= 16;
81 }
82 if (!(x & 0xff000000u)) {
83 x <<= 8;
84 r -= 8;
85 }
86 if (!(x & 0xf0000000u)) {
87 x <<= 4;
88 r -= 4;
89 }
90 if (!(x & 0xc0000000u)) {
91 x <<= 2;
92 r -= 2;
93 }
94 if (!(x & 0x80000000u)) {
95 x <<= 1;
96 r -= 1;
97 }
98 return r;
99 }
100
101
102 /*
103 * hweightN: returns the hamming weight (i.e. the number
104 * of bits set) of a N-bit word
105 */
106
generic_hweight32(unsigned int w)107 static inline unsigned int generic_hweight32(unsigned int w)
108 {
109 unsigned int res = (w & 0x55555555) + ((w >> 1) & 0x55555555);
110 res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
111 res = (res & 0x0F0F0F0F) + ((res >> 4) & 0x0F0F0F0F);
112 res = (res & 0x00FF00FF) + ((res >> 8) & 0x00FF00FF);
113 return (res & 0x0000FFFF) + ((res >> 16) & 0x0000FFFF);
114 }
115
generic_hweight16(unsigned int w)116 static inline unsigned int generic_hweight16(unsigned int w)
117 {
118 unsigned int res = (w & 0x5555) + ((w >> 1) & 0x5555);
119 res = (res & 0x3333) + ((res >> 2) & 0x3333);
120 res = (res & 0x0F0F) + ((res >> 4) & 0x0F0F);
121 return (res & 0x00FF) + ((res >> 8) & 0x00FF);
122 }
123
generic_hweight8(unsigned int w)124 static inline unsigned int generic_hweight8(unsigned int w)
125 {
126 unsigned int res = (w & 0x55) + ((w >> 1) & 0x55);
127 res = (res & 0x33) + ((res >> 2) & 0x33);
128 return (res & 0x0F) + ((res >> 4) & 0x0F);
129 }
130
131 #include <asm/bitops.h>
132
133 /* linux/include/asm-generic/bitops/non-atomic.h */
134
135 #ifndef PLATFORM__SET_BIT
136 # define __set_bit generic_set_bit
137 #endif
138
139 #ifndef PLATFORM__CLEAR_BIT
140 # define __clear_bit generic_clear_bit
141 #endif
142
143 #ifndef PLATFORM_FFS
144 # define ffs generic_ffs
145 #endif
146
147 #ifndef PLATFORM_FLS
148 # define fls generic_fls
149 #endif
150
fls_long(unsigned long l)151 static inline unsigned fls_long(unsigned long l)
152 {
153 if (sizeof(l) == 4)
154 return fls(l);
155 return fls64(l);
156 }
157
158 /**
159 * __ffs64 - find first set bit in a 64 bit word
160 * @word: The 64 bit word
161 *
162 * On 64 bit arches this is a synomyn for __ffs
163 * The result is not defined if no bits are set, so check that @word
164 * is non-zero before calling this.
165 */
__ffs64(u64 word)166 static inline unsigned long __ffs64(u64 word)
167 {
168 #if BITS_PER_LONG == 32
169 if (((u32)word) == 0UL)
170 return __ffs((u32)(word >> 32)) + 32;
171 #elif BITS_PER_LONG != 64
172 #error BITS_PER_LONG not 32 or 64
173 #endif
174 return __ffs((unsigned long)word);
175 }
176
177 /**
178 * __set_bit - Set a bit in memory
179 * @nr: the bit to set
180 * @addr: the address to start counting from
181 *
182 * Unlike set_bit(), this function is non-atomic and may be reordered.
183 * If it's called on the same region of memory simultaneously, the effect
184 * may be that only one operation succeeds.
185 */
generic_set_bit(int nr,volatile unsigned long * addr)186 static inline void generic_set_bit(int nr, volatile unsigned long *addr)
187 {
188 unsigned long mask = BIT_MASK(nr);
189 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
190
191 *p |= mask;
192 }
193
generic_clear_bit(int nr,volatile unsigned long * addr)194 static inline void generic_clear_bit(int nr, volatile unsigned long *addr)
195 {
196 unsigned long mask = BIT_MASK(nr);
197 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
198
199 *p &= ~mask;
200 }
201
202 #endif
203