2 * bitops.h: Bit string operations on the ppc
8 #include <asm/byteorder.h>
9 #include <asm-generic/bitops/__ffs.h>
12 * Arguably these bit operations don't imply any memory barrier or
13 * SMP ordering, but in fact a lot of drivers expect them to imply
14 * both, since they do on x86 cpus.
17 #define SMP_WMB "eieio\n"
18 #define SMP_MB "\nsync"
22 #endif /* CONFIG_SMP */
24 #define __INLINE_BITOPS 1
28 * These used to be if'd out here because using : "cc" as a constraint
29 * resulted in errors from egcs. Things may be OK with gcc-2.95.
31 static __inline__ void set_bit(int nr, volatile void * addr)
34 unsigned long mask = 1 << (nr & 0x1f);
35 unsigned long *p = ((unsigned long *)addr) + (nr >> 5);
37 __asm__ __volatile__(SMP_WMB "\
43 : "=&r" (old), "=m" (*p)
44 : "r" (mask), "r" (p), "m" (*p)
48 static __inline__ void clear_bit(int nr, volatile void *addr)
51 unsigned long mask = 1 << (nr & 0x1f);
52 unsigned long *p = ((unsigned long *)addr) + (nr >> 5);
54 __asm__ __volatile__(SMP_WMB "\
60 : "=&r" (old), "=m" (*p)
61 : "r" (mask), "r" (p), "m" (*p)
65 static __inline__ void change_bit(int nr, volatile void *addr)
68 unsigned long mask = 1 << (nr & 0x1f);
69 unsigned long *p = ((unsigned long *)addr) + (nr >> 5);
71 __asm__ __volatile__(SMP_WMB "\
77 : "=&r" (old), "=m" (*p)
78 : "r" (mask), "r" (p), "m" (*p)
82 static __inline__ int test_and_set_bit(int nr, volatile void *addr)
85 unsigned int mask = 1 << (nr & 0x1f);
86 volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5);
88 __asm__ __volatile__(SMP_WMB "\
94 : "=&r" (old), "=&r" (t), "=m" (*p)
95 : "r" (mask), "r" (p), "m" (*p)
98 return (old & mask) != 0;
101 static __inline__ int test_and_clear_bit(int nr, volatile void *addr)
104 unsigned int mask = 1 << (nr & 0x1f);
105 volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5);
107 __asm__ __volatile__(SMP_WMB "\
113 : "=&r" (old), "=&r" (t), "=m" (*p)
114 : "r" (mask), "r" (p), "m" (*p)
117 return (old & mask) != 0;
120 static __inline__ int test_and_change_bit(int nr, volatile void *addr)
123 unsigned int mask = 1 << (nr & 0x1f);
124 volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5);
126 __asm__ __volatile__(SMP_WMB "\
132 : "=&r" (old), "=&r" (t), "=m" (*p)
133 : "r" (mask), "r" (p), "m" (*p)
136 return (old & mask) != 0;
138 #endif /* __INLINE_BITOPS */
140 static __inline__ int test_bit(int nr, __const__ volatile void *addr)
142 __const__ unsigned int *p = (__const__ unsigned int *) addr;
144 return ((p[nr >> 5] >> (nr & 0x1f)) & 1) != 0;
147 /* Return the bit position of the most significant 1 bit in a word */
148 /* - the result is undefined when x == 0 */
149 static __inline__ int __ilog2(unsigned int x)
153 asm ("cntlzw %0,%1" : "=r" (lz) : "r" (x));
157 static __inline__ int ffz(unsigned int x)
161 return __ilog2(x & -x);
165 * fls: find last (most-significant) bit set.
166 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
168 * On powerpc, __ilog2(0) returns -1, but this is not safe in general
170 static __inline__ int fls(unsigned int x)
172 return __ilog2(x) + 1;
177 * fls64 - find last set bit in a 64-bit word
178 * @x: the word to search
180 * This is defined in a similar way as the libc and compiler builtin
181 * ffsll, but returns the position of the most significant set bit.
183 * fls64(value) returns 0 if value is 0 or the position of the last
184 * set bit if value is nonzero. The last (most significant) bit is
187 #if BITS_PER_LONG == 32
188 static inline int fls64(__u64 x)
195 #elif BITS_PER_LONG == 64
196 static inline int fls64(__u64 x)
200 return __ilog2(x) + 1;
203 #error BITS_PER_LONG not 32 or 64
209 * ffs: find first bit set. This is defined the same way as
210 * the libc and compiler builtin ffs routines, therefore
211 * differs in spirit from the above ffz (man ffs).
213 static __inline__ int ffs(int x)
215 return __ilog2(x & -x) + 1;
220 * hweightN: returns the hamming weight (i.e. the number
221 * of bits set) of a N-bit word
224 #define hweight32(x) generic_hweight32(x)
225 #define hweight16(x) generic_hweight16(x)
226 #define hweight8(x) generic_hweight8(x)
228 #endif /* __KERNEL__ */
231 * This implementation of find_{first,next}_zero_bit was stolen from
232 * Linus' asm-alpha/bitops.h.
234 #define find_first_zero_bit(addr, size) \
235 find_next_zero_bit((addr), (size), 0)
237 static __inline__ unsigned long find_next_zero_bit(void * addr,
238 unsigned long size, unsigned long offset)
240 unsigned int * p = ((unsigned int *) addr) + (offset >> 5);
241 unsigned int result = offset & ~31UL;
250 tmp |= ~0UL >> (32-offset);
259 if ((tmp = *p++) != ~0U)
270 return result + ffz(tmp);
274 #define _EXT2_HAVE_ASM_BITOPS_
278 * test_and_{set,clear}_bit guarantee atomicity without
279 * disabling interrupts.
281 #define ext2_set_bit(nr, addr) test_and_set_bit((nr) ^ 0x18, addr)
282 #define ext2_clear_bit(nr, addr) test_and_clear_bit((nr) ^ 0x18, addr)
285 static __inline__ int ext2_set_bit(int nr, void * addr)
288 unsigned char *ADDR = (unsigned char *) addr;
292 mask = 1 << (nr & 0x07);
293 oldbit = (*ADDR & mask) ? 1 : 0;
298 static __inline__ int ext2_clear_bit(int nr, void * addr)
301 unsigned char *ADDR = (unsigned char *) addr;
305 mask = 1 << (nr & 0x07);
306 oldbit = (*ADDR & mask) ? 1 : 0;
307 *ADDR = *ADDR & ~mask;
310 #endif /* __KERNEL__ */
312 static __inline__ int ext2_test_bit(int nr, __const__ void * addr)
314 __const__ unsigned char *ADDR = (__const__ unsigned char *) addr;
316 return (ADDR[nr >> 3] >> (nr & 7)) & 1;
320 * This implementation of ext2_find_{first,next}_zero_bit was stolen from
321 * Linus' asm-alpha/bitops.h and modified for a big-endian machine.
324 #define ext2_find_first_zero_bit(addr, size) \
325 ext2_find_next_zero_bit((addr), (size), 0)
327 static __inline__ unsigned long ext2_find_next_zero_bit(void *addr,
328 unsigned long size, unsigned long offset)
330 unsigned int *p = ((unsigned int *) addr) + (offset >> 5);
331 unsigned int result = offset & ~31UL;
339 tmp = cpu_to_le32p(p++);
340 tmp |= ~0UL >> (32-offset);
349 if ((tmp = cpu_to_le32p(p++)) != ~0U)
356 tmp = cpu_to_le32p(p);
360 return result + ffz(tmp);
363 /* Bitmap functions for the minix filesystem. */
364 #define minix_test_and_set_bit(nr,addr) ext2_set_bit(nr,addr)
365 #define minix_set_bit(nr,addr) ((void)ext2_set_bit(nr,addr))
366 #define minix_test_and_clear_bit(nr,addr) ext2_clear_bit(nr,addr)
367 #define minix_test_bit(nr,addr) ext2_test_bit(nr,addr)
368 #define minix_find_first_zero_bit(addr,size) ext2_find_first_zero_bit(addr,size)
370 #endif /* _PPC_BITOPS_H */