2 * bitops.h: Bit string operations on the ppc
8 #include <asm/byteorder.h>
9 #include <asm-generic/bitops/__ffs.h>
11 extern void set_bit(int nr, volatile void *addr);
12 extern void clear_bit(int nr, volatile void *addr);
13 extern void change_bit(int nr, volatile void *addr);
14 extern int test_and_set_bit(int nr, volatile void *addr);
15 extern int test_and_clear_bit(int nr, volatile void *addr);
16 extern int test_and_change_bit(int nr, volatile void *addr);
19 * Arguably these bit operations don't imply any memory barrier or
20 * SMP ordering, but in fact a lot of drivers expect them to imply
21 * both, since they do on x86 cpus.
24 #define SMP_WMB "eieio\n"
25 #define SMP_MB "\nsync"
29 #endif /* CONFIG_SMP */
31 #define __INLINE_BITOPS 1
35 * These used to be if'd out here because using : "cc" as a constraint
36 * resulted in errors from egcs. Things may be OK with gcc-2.95.
38 extern __inline__ void set_bit(int nr, volatile void * addr)
41 unsigned long mask = 1 << (nr & 0x1f);
42 unsigned long *p = ((unsigned long *)addr) + (nr >> 5);
44 __asm__ __volatile__(SMP_WMB "\
50 : "=&r" (old), "=m" (*p)
51 : "r" (mask), "r" (p), "m" (*p)
55 extern __inline__ void clear_bit(int nr, volatile void *addr)
58 unsigned long mask = 1 << (nr & 0x1f);
59 unsigned long *p = ((unsigned long *)addr) + (nr >> 5);
61 __asm__ __volatile__(SMP_WMB "\
67 : "=&r" (old), "=m" (*p)
68 : "r" (mask), "r" (p), "m" (*p)
72 extern __inline__ void change_bit(int nr, volatile void *addr)
75 unsigned long mask = 1 << (nr & 0x1f);
76 unsigned long *p = ((unsigned long *)addr) + (nr >> 5);
78 __asm__ __volatile__(SMP_WMB "\
84 : "=&r" (old), "=m" (*p)
85 : "r" (mask), "r" (p), "m" (*p)
89 extern __inline__ int test_and_set_bit(int nr, volatile void *addr)
92 unsigned int mask = 1 << (nr & 0x1f);
93 volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5);
95 __asm__ __volatile__(SMP_WMB "\
101 : "=&r" (old), "=&r" (t), "=m" (*p)
102 : "r" (mask), "r" (p), "m" (*p)
105 return (old & mask) != 0;
108 extern __inline__ int test_and_clear_bit(int nr, volatile void *addr)
111 unsigned int mask = 1 << (nr & 0x1f);
112 volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5);
114 __asm__ __volatile__(SMP_WMB "\
120 : "=&r" (old), "=&r" (t), "=m" (*p)
121 : "r" (mask), "r" (p), "m" (*p)
124 return (old & mask) != 0;
127 extern __inline__ int test_and_change_bit(int nr, volatile void *addr)
130 unsigned int mask = 1 << (nr & 0x1f);
131 volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5);
133 __asm__ __volatile__(SMP_WMB "\
139 : "=&r" (old), "=&r" (t), "=m" (*p)
140 : "r" (mask), "r" (p), "m" (*p)
143 return (old & mask) != 0;
145 #endif /* __INLINE_BITOPS */
147 extern __inline__ int test_bit(int nr, __const__ volatile void *addr)
149 __const__ unsigned int *p = (__const__ unsigned int *) addr;
151 return ((p[nr >> 5] >> (nr & 0x1f)) & 1) != 0;
154 /* Return the bit position of the most significant 1 bit in a word */
155 /* - the result is undefined when x == 0 */
156 extern __inline__ int __ilog2(unsigned int x)
160 asm ("cntlzw %0,%1" : "=r" (lz) : "r" (x));
164 extern __inline__ int ffz(unsigned int x)
168 return __ilog2(x & -x);
172 * fls: find last (most-significant) bit set.
173 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
175 * On powerpc, __ilog2(0) returns -1, but this is not safe in general
177 static __inline__ int fls(unsigned int x)
179 return __ilog2(x) + 1;
184 * fls64 - find last set bit in a 64-bit word
185 * @x: the word to search
187 * This is defined in a similar way as the libc and compiler builtin
188 * ffsll, but returns the position of the most significant set bit.
190 * fls64(value) returns 0 if value is 0 or the position of the last
191 * set bit if value is nonzero. The last (most significant) bit is
194 #if BITS_PER_LONG == 32
195 static inline int fls64(__u64 x)
202 #elif BITS_PER_LONG == 64
203 static inline int fls64(__u64 x)
207 return __ilog2(x) + 1;
210 #error BITS_PER_LONG not 32 or 64
216 * ffs: find first bit set. This is defined the same way as
217 * the libc and compiler builtin ffs routines, therefore
218 * differs in spirit from the above ffz (man ffs).
220 extern __inline__ int ffs(int x)
222 return __ilog2(x & -x) + 1;
227 * hweightN: returns the hamming weight (i.e. the number
228 * of bits set) of a N-bit word
231 #define hweight32(x) generic_hweight32(x)
232 #define hweight16(x) generic_hweight16(x)
233 #define hweight8(x) generic_hweight8(x)
235 #endif /* __KERNEL__ */
238 * This implementation of find_{first,next}_zero_bit was stolen from
239 * Linus' asm-alpha/bitops.h.
241 #define find_first_zero_bit(addr, size) \
242 find_next_zero_bit((addr), (size), 0)
244 extern __inline__ unsigned long find_next_zero_bit(void * addr,
245 unsigned long size, unsigned long offset)
247 unsigned int * p = ((unsigned int *) addr) + (offset >> 5);
248 unsigned int result = offset & ~31UL;
257 tmp |= ~0UL >> (32-offset);
266 if ((tmp = *p++) != ~0U)
277 return result + ffz(tmp);
281 #define _EXT2_HAVE_ASM_BITOPS_
285 * test_and_{set,clear}_bit guarantee atomicity without
286 * disabling interrupts.
288 #define ext2_set_bit(nr, addr) test_and_set_bit((nr) ^ 0x18, addr)
289 #define ext2_clear_bit(nr, addr) test_and_clear_bit((nr) ^ 0x18, addr)
292 extern __inline__ int ext2_set_bit(int nr, void * addr)
295 unsigned char *ADDR = (unsigned char *) addr;
299 mask = 1 << (nr & 0x07);
300 oldbit = (*ADDR & mask) ? 1 : 0;
305 extern __inline__ int ext2_clear_bit(int nr, void * addr)
308 unsigned char *ADDR = (unsigned char *) addr;
312 mask = 1 << (nr & 0x07);
313 oldbit = (*ADDR & mask) ? 1 : 0;
314 *ADDR = *ADDR & ~mask;
317 #endif /* __KERNEL__ */
319 extern __inline__ int ext2_test_bit(int nr, __const__ void * addr)
321 __const__ unsigned char *ADDR = (__const__ unsigned char *) addr;
323 return (ADDR[nr >> 3] >> (nr & 7)) & 1;
327 * This implementation of ext2_find_{first,next}_zero_bit was stolen from
328 * Linus' asm-alpha/bitops.h and modified for a big-endian machine.
331 #define ext2_find_first_zero_bit(addr, size) \
332 ext2_find_next_zero_bit((addr), (size), 0)
334 static __inline__ unsigned long ext2_find_next_zero_bit(void *addr,
335 unsigned long size, unsigned long offset)
337 unsigned int *p = ((unsigned int *) addr) + (offset >> 5);
338 unsigned int result = offset & ~31UL;
346 tmp = cpu_to_le32p(p++);
347 tmp |= ~0UL >> (32-offset);
356 if ((tmp = cpu_to_le32p(p++)) != ~0U)
363 tmp = cpu_to_le32p(p);
367 return result + ffz(tmp);
370 /* Bitmap functions for the minix filesystem. */
371 #define minix_test_and_set_bit(nr,addr) ext2_set_bit(nr,addr)
372 #define minix_set_bit(nr,addr) ((void)ext2_set_bit(nr,addr))
373 #define minix_test_and_clear_bit(nr,addr) ext2_clear_bit(nr,addr)
374 #define minix_test_bit(nr,addr) ext2_test_bit(nr,addr)
375 #define minix_find_first_zero_bit(addr,size) ext2_find_first_zero_bit(addr,size)
377 #endif /* _PPC_BITOPS_H */