xref: /openbmc/u-boot/arch/powerpc/include/asm/bitops.h (revision 5be93569)
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  */
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 
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 
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 
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 
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 
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 
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 */
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 
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  */
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
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
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  */
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 
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
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 
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 
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 
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