1 /*
2 * bitops.h: Bit string operations on the ppc
3 */
4
5 #ifndef _PPC_BITOPS_H
6 #define _PPC_BITOPS_H
7
8 #include <asm/byteorder.h>
9 #include <asm-generic/bitops/__ffs.h>
10
11 /*
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.
15 */
16 #ifdef CONFIG_SMP
17 #define SMP_WMB "eieio\n"
18 #define SMP_MB "\nsync"
19 #else
20 #define SMP_WMB
21 #define SMP_MB
22 #endif /* CONFIG_SMP */
23
24 #define __INLINE_BITOPS 1
25
26 #if __INLINE_BITOPS
27 /*
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.
30 */
set_bit(int nr,volatile void * addr)31 static __inline__ void set_bit(int nr, volatile void * addr)
32 {
33 unsigned long old;
34 unsigned long mask = 1 << (nr & 0x1f);
35 unsigned long *p = ((unsigned long *)addr) + (nr >> 5);
36
37 __asm__ __volatile__(SMP_WMB "\
38 1: lwarx %0,0,%3\n\
39 or %0,%0,%2\n\
40 stwcx. %0,0,%3\n\
41 bne 1b"
42 SMP_MB
43 : "=&r" (old), "=m" (*p)
44 : "r" (mask), "r" (p), "m" (*p)
45 : "cc" );
46 }
47
clear_bit(int nr,volatile void * addr)48 static __inline__ void clear_bit(int nr, volatile void *addr)
49 {
50 unsigned long old;
51 unsigned long mask = 1 << (nr & 0x1f);
52 unsigned long *p = ((unsigned long *)addr) + (nr >> 5);
53
54 __asm__ __volatile__(SMP_WMB "\
55 1: lwarx %0,0,%3\n\
56 andc %0,%0,%2\n\
57 stwcx. %0,0,%3\n\
58 bne 1b"
59 SMP_MB
60 : "=&r" (old), "=m" (*p)
61 : "r" (mask), "r" (p), "m" (*p)
62 : "cc");
63 }
64
change_bit(int nr,volatile void * addr)65 static __inline__ void change_bit(int nr, volatile void *addr)
66 {
67 unsigned long old;
68 unsigned long mask = 1 << (nr & 0x1f);
69 unsigned long *p = ((unsigned long *)addr) + (nr >> 5);
70
71 __asm__ __volatile__(SMP_WMB "\
72 1: lwarx %0,0,%3\n\
73 xor %0,%0,%2\n\
74 stwcx. %0,0,%3\n\
75 bne 1b"
76 SMP_MB
77 : "=&r" (old), "=m" (*p)
78 : "r" (mask), "r" (p), "m" (*p)
79 : "cc");
80 }
81
test_and_set_bit(int nr,volatile void * addr)82 static __inline__ int test_and_set_bit(int nr, volatile void *addr)
83 {
84 unsigned int old, t;
85 unsigned int mask = 1 << (nr & 0x1f);
86 volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5);
87
88 __asm__ __volatile__(SMP_WMB "\
89 1: lwarx %0,0,%4\n\
90 or %1,%0,%3\n\
91 stwcx. %1,0,%4\n\
92 bne 1b"
93 SMP_MB
94 : "=&r" (old), "=&r" (t), "=m" (*p)
95 : "r" (mask), "r" (p), "m" (*p)
96 : "cc");
97
98 return (old & mask) != 0;
99 }
100
test_and_clear_bit(int nr,volatile void * addr)101 static __inline__ int test_and_clear_bit(int nr, volatile void *addr)
102 {
103 unsigned int old, t;
104 unsigned int mask = 1 << (nr & 0x1f);
105 volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5);
106
107 __asm__ __volatile__(SMP_WMB "\
108 1: lwarx %0,0,%4\n\
109 andc %1,%0,%3\n\
110 stwcx. %1,0,%4\n\
111 bne 1b"
112 SMP_MB
113 : "=&r" (old), "=&r" (t), "=m" (*p)
114 : "r" (mask), "r" (p), "m" (*p)
115 : "cc");
116
117 return (old & mask) != 0;
118 }
119
test_and_change_bit(int nr,volatile void * addr)120 static __inline__ int test_and_change_bit(int nr, volatile void *addr)
121 {
122 unsigned int old, t;
123 unsigned int mask = 1 << (nr & 0x1f);
124 volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5);
125
126 __asm__ __volatile__(SMP_WMB "\
127 1: lwarx %0,0,%4\n\
128 xor %1,%0,%3\n\
129 stwcx. %1,0,%4\n\
130 bne 1b"
131 SMP_MB
132 : "=&r" (old), "=&r" (t), "=m" (*p)
133 : "r" (mask), "r" (p), "m" (*p)
134 : "cc");
135
136 return (old & mask) != 0;
137 }
138 #endif /* __INLINE_BITOPS */
139
test_bit(int nr,__const__ volatile void * addr)140 static __inline__ int test_bit(int nr, __const__ volatile void *addr)
141 {
142 __const__ unsigned int *p = (__const__ unsigned int *) addr;
143
144 return ((p[nr >> 5] >> (nr & 0x1f)) & 1) != 0;
145 }
146
147 /* Return the bit position of the most significant 1 bit in a word */
148 /* - the result is undefined when x == 0 */
__ilog2(unsigned int x)149 static __inline__ int __ilog2(unsigned int x)
150 {
151 int lz;
152
153 asm ("cntlzw %0,%1" : "=r" (lz) : "r" (x));
154 return 31 - lz;
155 }
156
ffz(unsigned int x)157 static __inline__ int ffz(unsigned int x)
158 {
159 if ((x = ~x) == 0)
160 return 32;
161 return __ilog2(x & -x);
162 }
163
164 /*
165 * fls: find last (most-significant) bit set.
166 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
167 *
168 * On powerpc, __ilog2(0) returns -1, but this is not safe in general
169 */
fls(unsigned int x)170 static __inline__ int fls(unsigned int x)
171 {
172 return __ilog2(x) + 1;
173 }
174 #define PLATFORM_FLS
175
176 /**
177 * fls64 - find last set bit in a 64-bit word
178 * @x: the word to search
179 *
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.
182 *
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
185 * at position 64.
186 */
187 #if BITS_PER_LONG == 32
fls64(__u64 x)188 static inline int fls64(__u64 x)
189 {
190 __u32 h = x >> 32;
191 if (h)
192 return fls(h) + 32;
193 return fls(x);
194 }
195 #elif BITS_PER_LONG == 64
fls64(__u64 x)196 static inline int fls64(__u64 x)
197 {
198 if (x == 0)
199 return 0;
200 return __ilog2(x) + 1;
201 }
202 #else
203 #error BITS_PER_LONG not 32 or 64
204 #endif
205
206 #ifdef __KERNEL__
207
208 /*
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).
212 */
ffs(int x)213 static __inline__ int ffs(int x)
214 {
215 return __ilog2(x & -x) + 1;
216 }
217 #define PLATFORM_FFS
218
219 /*
220 * hweightN: returns the hamming weight (i.e. the number
221 * of bits set) of a N-bit word
222 */
223
224 #define hweight32(x) generic_hweight32(x)
225 #define hweight16(x) generic_hweight16(x)
226 #define hweight8(x) generic_hweight8(x)
227
228 #endif /* __KERNEL__ */
229
230 /*
231 * This implementation of find_{first,next}_zero_bit was stolen from
232 * Linus' asm-alpha/bitops.h.
233 */
234 #define find_first_zero_bit(addr, size) \
235 find_next_zero_bit((addr), (size), 0)
236
find_next_zero_bit(void * addr,unsigned long size,unsigned long offset)237 static __inline__ unsigned long find_next_zero_bit(void * addr,
238 unsigned long size, unsigned long offset)
239 {
240 unsigned int * p = ((unsigned int *) addr) + (offset >> 5);
241 unsigned int result = offset & ~31UL;
242 unsigned int tmp;
243
244 if (offset >= size)
245 return size;
246 size -= result;
247 offset &= 31UL;
248 if (offset) {
249 tmp = *p++;
250 tmp |= ~0UL >> (32-offset);
251 if (size < 32)
252 goto found_first;
253 if (tmp != ~0U)
254 goto found_middle;
255 size -= 32;
256 result += 32;
257 }
258 while (size >= 32) {
259 if ((tmp = *p++) != ~0U)
260 goto found_middle;
261 result += 32;
262 size -= 32;
263 }
264 if (!size)
265 return result;
266 tmp = *p;
267 found_first:
268 tmp |= ~0UL << size;
269 found_middle:
270 return result + ffz(tmp);
271 }
272
273
274 #define _EXT2_HAVE_ASM_BITOPS_
275
276 #ifdef __KERNEL__
277 /*
278 * test_and_{set,clear}_bit guarantee atomicity without
279 * disabling interrupts.
280 */
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)
283
284 #else
ext2_set_bit(int nr,void * addr)285 static __inline__ int ext2_set_bit(int nr, void * addr)
286 {
287 int mask;
288 unsigned char *ADDR = (unsigned char *) addr;
289 int oldbit;
290
291 ADDR += nr >> 3;
292 mask = 1 << (nr & 0x07);
293 oldbit = (*ADDR & mask) ? 1 : 0;
294 *ADDR |= mask;
295 return oldbit;
296 }
297
ext2_clear_bit(int nr,void * addr)298 static __inline__ int ext2_clear_bit(int nr, void * addr)
299 {
300 int mask;
301 unsigned char *ADDR = (unsigned char *) addr;
302 int oldbit;
303
304 ADDR += nr >> 3;
305 mask = 1 << (nr & 0x07);
306 oldbit = (*ADDR & mask) ? 1 : 0;
307 *ADDR = *ADDR & ~mask;
308 return oldbit;
309 }
310 #endif /* __KERNEL__ */
311
ext2_test_bit(int nr,__const__ void * addr)312 static __inline__ int ext2_test_bit(int nr, __const__ void * addr)
313 {
314 __const__ unsigned char *ADDR = (__const__ unsigned char *) addr;
315
316 return (ADDR[nr >> 3] >> (nr & 7)) & 1;
317 }
318
319 /*
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.
322 */
323
324 #define ext2_find_first_zero_bit(addr, size) \
325 ext2_find_next_zero_bit((addr), (size), 0)
326
ext2_find_next_zero_bit(void * addr,unsigned long size,unsigned long offset)327 static __inline__ unsigned long ext2_find_next_zero_bit(void *addr,
328 unsigned long size, unsigned long offset)
329 {
330 unsigned int *p = ((unsigned int *) addr) + (offset >> 5);
331 unsigned int result = offset & ~31UL;
332 unsigned int tmp;
333
334 if (offset >= size)
335 return size;
336 size -= result;
337 offset &= 31UL;
338 if (offset) {
339 tmp = cpu_to_le32p(p++);
340 tmp |= ~0UL >> (32-offset);
341 if (size < 32)
342 goto found_first;
343 if (tmp != ~0U)
344 goto found_middle;
345 size -= 32;
346 result += 32;
347 }
348 while (size >= 32) {
349 if ((tmp = cpu_to_le32p(p++)) != ~0U)
350 goto found_middle;
351 result += 32;
352 size -= 32;
353 }
354 if (!size)
355 return result;
356 tmp = cpu_to_le32p(p);
357 found_first:
358 tmp |= ~0U << size;
359 found_middle:
360 return result + ffz(tmp);
361 }
362
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)
369
370 #endif /* _PPC_BITOPS_H */
371