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 #ifdef CONFIG_SANDBOX
25 #define GENMASK(h, l) \
26 (((~0UL) << (l)) & (~0UL >> (CONFIG_SANDBOX_BITS_PER_LONG - 1 - (h))))
27 #else
28 #define GENMASK(h, l) \
29 (((~0UL) << (l)) & (~0UL >> (BITS_PER_LONG - 1 - (h))))
30 #endif
31
32 #define GENMASK_ULL(h, l) \
33 (((~0ULL) << (l)) & (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h))))
34
35 /*
36 * ffs: find first bit set. This is defined the same way as
37 * the libc and compiler builtin ffs routines, therefore
38 * differs in spirit from the above ffz (man ffs).
39 */
40
generic_ffs(int x)41 static inline int generic_ffs(int x)
42 {
43 int r = 1;
44
45 if (!x)
46 return 0;
47 if (!(x & 0xffff)) {
48 x >>= 16;
49 r += 16;
50 }
51 if (!(x & 0xff)) {
52 x >>= 8;
53 r += 8;
54 }
55 if (!(x & 0xf)) {
56 x >>= 4;
57 r += 4;
58 }
59 if (!(x & 3)) {
60 x >>= 2;
61 r += 2;
62 }
63 if (!(x & 1)) {
64 x >>= 1;
65 r += 1;
66 }
67 return r;
68 }
69
70 /**
71 * fls - find last (most-significant) bit set
72 * @x: the word to search
73 *
74 * This is defined the same way as ffs.
75 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
76 */
generic_fls(int x)77 static inline int generic_fls(int x)
78 {
79 int r = 32;
80
81 if (!x)
82 return 0;
83 if (!(x & 0xffff0000u)) {
84 x <<= 16;
85 r -= 16;
86 }
87 if (!(x & 0xff000000u)) {
88 x <<= 8;
89 r -= 8;
90 }
91 if (!(x & 0xf0000000u)) {
92 x <<= 4;
93 r -= 4;
94 }
95 if (!(x & 0xc0000000u)) {
96 x <<= 2;
97 r -= 2;
98 }
99 if (!(x & 0x80000000u)) {
100 x <<= 1;
101 r -= 1;
102 }
103 return r;
104 }
105
106
107 /*
108 * hweightN: returns the hamming weight (i.e. the number
109 * of bits set) of a N-bit word
110 */
111
generic_hweight32(unsigned int w)112 static inline unsigned int generic_hweight32(unsigned int w)
113 {
114 unsigned int res = (w & 0x55555555) + ((w >> 1) & 0x55555555);
115 res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
116 res = (res & 0x0F0F0F0F) + ((res >> 4) & 0x0F0F0F0F);
117 res = (res & 0x00FF00FF) + ((res >> 8) & 0x00FF00FF);
118 return (res & 0x0000FFFF) + ((res >> 16) & 0x0000FFFF);
119 }
120
generic_hweight16(unsigned int w)121 static inline unsigned int generic_hweight16(unsigned int w)
122 {
123 unsigned int res = (w & 0x5555) + ((w >> 1) & 0x5555);
124 res = (res & 0x3333) + ((res >> 2) & 0x3333);
125 res = (res & 0x0F0F) + ((res >> 4) & 0x0F0F);
126 return (res & 0x00FF) + ((res >> 8) & 0x00FF);
127 }
128
generic_hweight8(unsigned int w)129 static inline unsigned int generic_hweight8(unsigned int w)
130 {
131 unsigned int res = (w & 0x55) + ((w >> 1) & 0x55);
132 res = (res & 0x33) + ((res >> 2) & 0x33);
133 return (res & 0x0F) + ((res >> 4) & 0x0F);
134 }
135
136 #include <asm/bitops.h>
137
138 /* linux/include/asm-generic/bitops/non-atomic.h */
139
140 #ifndef PLATFORM__SET_BIT
141 # define __set_bit generic_set_bit
142 #endif
143
144 #ifndef PLATFORM__CLEAR_BIT
145 # define __clear_bit generic_clear_bit
146 #endif
147
148 #ifndef PLATFORM_FFS
149 # define ffs generic_ffs
150 #endif
151
152 #ifndef PLATFORM_FLS
153 # define fls generic_fls
154 #endif
155
fls_long(unsigned long l)156 static inline unsigned fls_long(unsigned long l)
157 {
158 if (sizeof(l) == 4)
159 return fls(l);
160 return fls64(l);
161 }
162
163 /**
164 * __ffs64 - find first set bit in a 64 bit word
165 * @word: The 64 bit word
166 *
167 * On 64 bit arches this is a synomyn for __ffs
168 * The result is not defined if no bits are set, so check that @word
169 * is non-zero before calling this.
170 */
__ffs64(u64 word)171 static inline unsigned long __ffs64(u64 word)
172 {
173 #if BITS_PER_LONG == 32
174 if (((u32)word) == 0UL)
175 return __ffs((u32)(word >> 32)) + 32;
176 #elif BITS_PER_LONG != 64
177 #error BITS_PER_LONG not 32 or 64
178 #endif
179 return __ffs((unsigned long)word);
180 }
181
182 /**
183 * __set_bit - Set a bit in memory
184 * @nr: the bit to set
185 * @addr: the address to start counting from
186 *
187 * Unlike set_bit(), this function is non-atomic and may be reordered.
188 * If it's called on the same region of memory simultaneously, the effect
189 * may be that only one operation succeeds.
190 */
generic_set_bit(int nr,volatile unsigned long * addr)191 static inline void generic_set_bit(int nr, volatile unsigned long *addr)
192 {
193 unsigned long mask = BIT_MASK(nr);
194 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
195
196 *p |= mask;
197 }
198
generic_clear_bit(int nr,volatile unsigned long * addr)199 static inline void generic_clear_bit(int nr, volatile unsigned long *addr)
200 {
201 unsigned long mask = BIT_MASK(nr);
202 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
203
204 *p &= ~mask;
205 }
206
207 #endif
208