1 /*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (c) 1994 - 1997, 99, 2000, 06, 07 Ralf Baechle (ralf@linux-mips.org)
7 * Copyright (c) 1999, 2000 Silicon Graphics, Inc.
8 */
9 #ifndef _ASM_BITOPS_H
10 #define _ASM_BITOPS_H
11
12 #ifndef _LINUX_BITOPS_H
13 #error only <linux/bitops.h> can be included directly
14 #endif
15
16 #include <linux/bits.h>
17 #include <linux/compiler.h>
18 #include <linux/types.h>
19 #include <asm/asm.h>
20 #include <asm/barrier.h>
21 #include <asm/byteorder.h> /* sigh ... */
22 #include <asm/compiler.h>
23 #include <asm/cpu-features.h>
24 #include <asm/sgidefs.h>
25
26 #define __bit_op(mem, insn, inputs...) do { \
27 unsigned long __temp; \
28 \
29 asm volatile( \
30 " .set push \n" \
31 " .set " MIPS_ISA_LEVEL " \n" \
32 " " __SYNC(full, loongson3_war) " \n" \
33 "1: " __stringify(LONG_LL) " %0, %1 \n" \
34 " " insn " \n" \
35 " " __stringify(LONG_SC) " %0, %1 \n" \
36 " " __stringify(SC_BEQZ) " %0, 1b \n" \
37 " .set pop \n" \
38 : "=&r"(__temp), "+" GCC_OFF_SMALL_ASM()(mem) \
39 : inputs \
40 : __LLSC_CLOBBER); \
41 } while (0)
42
43 #define __test_bit_op(mem, ll_dst, insn, inputs...) ({ \
44 unsigned long __orig, __temp; \
45 \
46 asm volatile( \
47 " .set push \n" \
48 " .set " MIPS_ISA_LEVEL " \n" \
49 " " __SYNC(full, loongson3_war) " \n" \
50 "1: " __stringify(LONG_LL) " " ll_dst ", %2\n" \
51 " " insn " \n" \
52 " " __stringify(LONG_SC) " %1, %2 \n" \
53 " " __stringify(SC_BEQZ) " %1, 1b \n" \
54 " .set pop \n" \
55 : "=&r"(__orig), "=&r"(__temp), \
56 "+" GCC_OFF_SMALL_ASM()(mem) \
57 : inputs \
58 : __LLSC_CLOBBER); \
59 \
60 __orig; \
61 })
62
63 /*
64 * These are the "slower" versions of the functions and are in bitops.c.
65 * These functions call raw_local_irq_{save,restore}().
66 */
67 void __mips_set_bit(unsigned long nr, volatile unsigned long *addr);
68 void __mips_clear_bit(unsigned long nr, volatile unsigned long *addr);
69 void __mips_change_bit(unsigned long nr, volatile unsigned long *addr);
70 int __mips_test_and_set_bit_lock(unsigned long nr,
71 volatile unsigned long *addr);
72 int __mips_test_and_clear_bit(unsigned long nr,
73 volatile unsigned long *addr);
74 int __mips_test_and_change_bit(unsigned long nr,
75 volatile unsigned long *addr);
76
77
78 /*
79 * set_bit - Atomically set a bit in memory
80 * @nr: the bit to set
81 * @addr: the address to start counting from
82 *
83 * This function is atomic and may not be reordered. See __set_bit()
84 * if you do not require the atomic guarantees.
85 * Note that @nr may be almost arbitrarily large; this function is not
86 * restricted to acting on a single-word quantity.
87 */
set_bit(unsigned long nr,volatile unsigned long * addr)88 static inline void set_bit(unsigned long nr, volatile unsigned long *addr)
89 {
90 volatile unsigned long *m = &addr[BIT_WORD(nr)];
91 int bit = nr % BITS_PER_LONG;
92
93 if (!kernel_uses_llsc) {
94 __mips_set_bit(nr, addr);
95 return;
96 }
97
98 if ((MIPS_ISA_REV >= 2) && __builtin_constant_p(bit) && (bit >= 16)) {
99 __bit_op(*m, __stringify(LONG_INS) " %0, %3, %2, 1", "i"(bit), "r"(~0));
100 return;
101 }
102
103 __bit_op(*m, "or\t%0, %2", "ir"(BIT(bit)));
104 }
105
106 /*
107 * clear_bit - Clears a bit in memory
108 * @nr: Bit to clear
109 * @addr: Address to start counting from
110 *
111 * clear_bit() is atomic and may not be reordered. However, it does
112 * not contain a memory barrier, so if it is used for locking purposes,
113 * you should call smp_mb__before_atomic() and/or smp_mb__after_atomic()
114 * in order to ensure changes are visible on other processors.
115 */
clear_bit(unsigned long nr,volatile unsigned long * addr)116 static inline void clear_bit(unsigned long nr, volatile unsigned long *addr)
117 {
118 volatile unsigned long *m = &addr[BIT_WORD(nr)];
119 int bit = nr % BITS_PER_LONG;
120
121 if (!kernel_uses_llsc) {
122 __mips_clear_bit(nr, addr);
123 return;
124 }
125
126 if ((MIPS_ISA_REV >= 2) && __builtin_constant_p(bit)) {
127 __bit_op(*m, __stringify(LONG_INS) " %0, $0, %2, 1", "i"(bit));
128 return;
129 }
130
131 __bit_op(*m, "and\t%0, %2", "ir"(~BIT(bit)));
132 }
133
134 /*
135 * clear_bit_unlock - Clears a bit in memory
136 * @nr: Bit to clear
137 * @addr: Address to start counting from
138 *
139 * clear_bit() is atomic and implies release semantics before the memory
140 * operation. It can be used for an unlock.
141 */
clear_bit_unlock(unsigned long nr,volatile unsigned long * addr)142 static inline void clear_bit_unlock(unsigned long nr, volatile unsigned long *addr)
143 {
144 smp_mb__before_atomic();
145 clear_bit(nr, addr);
146 }
147
148 /*
149 * change_bit - Toggle a bit in memory
150 * @nr: Bit to change
151 * @addr: Address to start counting from
152 *
153 * change_bit() is atomic and may not be reordered.
154 * Note that @nr may be almost arbitrarily large; this function is not
155 * restricted to acting on a single-word quantity.
156 */
change_bit(unsigned long nr,volatile unsigned long * addr)157 static inline void change_bit(unsigned long nr, volatile unsigned long *addr)
158 {
159 volatile unsigned long *m = &addr[BIT_WORD(nr)];
160 int bit = nr % BITS_PER_LONG;
161
162 if (!kernel_uses_llsc) {
163 __mips_change_bit(nr, addr);
164 return;
165 }
166
167 __bit_op(*m, "xor\t%0, %2", "ir"(BIT(bit)));
168 }
169
170 /*
171 * test_and_set_bit_lock - Set a bit and return its old value
172 * @nr: Bit to set
173 * @addr: Address to count from
174 *
175 * This operation is atomic and implies acquire ordering semantics
176 * after the memory operation.
177 */
test_and_set_bit_lock(unsigned long nr,volatile unsigned long * addr)178 static inline int test_and_set_bit_lock(unsigned long nr,
179 volatile unsigned long *addr)
180 {
181 volatile unsigned long *m = &addr[BIT_WORD(nr)];
182 int bit = nr % BITS_PER_LONG;
183 unsigned long res, orig;
184
185 if (!kernel_uses_llsc) {
186 res = __mips_test_and_set_bit_lock(nr, addr);
187 } else {
188 orig = __test_bit_op(*m, "%0",
189 "or\t%1, %0, %3",
190 "ir"(BIT(bit)));
191 res = (orig & BIT(bit)) != 0;
192 }
193
194 smp_llsc_mb();
195
196 return res;
197 }
198
199 /*
200 * test_and_set_bit - Set a bit and return its old value
201 * @nr: Bit to set
202 * @addr: Address to count from
203 *
204 * This operation is atomic and cannot be reordered.
205 * It also implies a memory barrier.
206 */
test_and_set_bit(unsigned long nr,volatile unsigned long * addr)207 static inline int test_and_set_bit(unsigned long nr,
208 volatile unsigned long *addr)
209 {
210 smp_mb__before_atomic();
211 return test_and_set_bit_lock(nr, addr);
212 }
213
214 /*
215 * test_and_clear_bit - Clear a bit and return its old value
216 * @nr: Bit to clear
217 * @addr: Address to count from
218 *
219 * This operation is atomic and cannot be reordered.
220 * It also implies a memory barrier.
221 */
test_and_clear_bit(unsigned long nr,volatile unsigned long * addr)222 static inline int test_and_clear_bit(unsigned long nr,
223 volatile unsigned long *addr)
224 {
225 volatile unsigned long *m = &addr[BIT_WORD(nr)];
226 int bit = nr % BITS_PER_LONG;
227 unsigned long res, orig;
228
229 smp_mb__before_atomic();
230
231 if (!kernel_uses_llsc) {
232 res = __mips_test_and_clear_bit(nr, addr);
233 } else if ((MIPS_ISA_REV >= 2) && __builtin_constant_p(nr)) {
234 res = __test_bit_op(*m, "%1",
235 __stringify(LONG_EXT) " %0, %1, %3, 1;"
236 __stringify(LONG_INS) " %1, $0, %3, 1",
237 "i"(bit));
238 } else {
239 orig = __test_bit_op(*m, "%0",
240 "or\t%1, %0, %3;"
241 "xor\t%1, %1, %3",
242 "ir"(BIT(bit)));
243 res = (orig & BIT(bit)) != 0;
244 }
245
246 smp_llsc_mb();
247
248 return res;
249 }
250
251 /*
252 * test_and_change_bit - Change a bit and return its old value
253 * @nr: Bit to change
254 * @addr: Address to count from
255 *
256 * This operation is atomic and cannot be reordered.
257 * It also implies a memory barrier.
258 */
test_and_change_bit(unsigned long nr,volatile unsigned long * addr)259 static inline int test_and_change_bit(unsigned long nr,
260 volatile unsigned long *addr)
261 {
262 volatile unsigned long *m = &addr[BIT_WORD(nr)];
263 int bit = nr % BITS_PER_LONG;
264 unsigned long res, orig;
265
266 smp_mb__before_atomic();
267
268 if (!kernel_uses_llsc) {
269 res = __mips_test_and_change_bit(nr, addr);
270 } else {
271 orig = __test_bit_op(*m, "%0",
272 "xor\t%1, %0, %3",
273 "ir"(BIT(bit)));
274 res = (orig & BIT(bit)) != 0;
275 }
276
277 smp_llsc_mb();
278
279 return res;
280 }
281
282 #undef __bit_op
283 #undef __test_bit_op
284
285 #include <asm-generic/bitops/non-atomic.h>
286
287 /*
288 * __clear_bit_unlock - Clears a bit in memory
289 * @nr: Bit to clear
290 * @addr: Address to start counting from
291 *
292 * __clear_bit() is non-atomic and implies release semantics before the memory
293 * operation. It can be used for an unlock if no other CPUs can concurrently
294 * modify other bits in the word.
295 */
__clear_bit_unlock(unsigned long nr,volatile unsigned long * addr)296 static inline void __clear_bit_unlock(unsigned long nr, volatile unsigned long *addr)
297 {
298 smp_mb__before_llsc();
299 __clear_bit(nr, addr);
300 nudge_writes();
301 }
302
303 /*
304 * Return the bit position (0..63) of the most significant 1 bit in a word
305 * Returns -1 if no 1 bit exists
306 */
__fls(unsigned long word)307 static __always_inline unsigned long __fls(unsigned long word)
308 {
309 int num;
310
311 if (BITS_PER_LONG == 32 && !__builtin_constant_p(word) &&
312 __builtin_constant_p(cpu_has_clo_clz) && cpu_has_clo_clz) {
313 __asm__(
314 " .set push \n"
315 " .set "MIPS_ISA_LEVEL" \n"
316 " clz %0, %1 \n"
317 " .set pop \n"
318 : "=r" (num)
319 : "r" (word));
320
321 return 31 - num;
322 }
323
324 if (BITS_PER_LONG == 64 && !__builtin_constant_p(word) &&
325 __builtin_constant_p(cpu_has_mips64) && cpu_has_mips64) {
326 __asm__(
327 " .set push \n"
328 " .set "MIPS_ISA_LEVEL" \n"
329 " dclz %0, %1 \n"
330 " .set pop \n"
331 : "=r" (num)
332 : "r" (word));
333
334 return 63 - num;
335 }
336
337 num = BITS_PER_LONG - 1;
338
339 #if BITS_PER_LONG == 64
340 if (!(word & (~0ul << 32))) {
341 num -= 32;
342 word <<= 32;
343 }
344 #endif
345 if (!(word & (~0ul << (BITS_PER_LONG-16)))) {
346 num -= 16;
347 word <<= 16;
348 }
349 if (!(word & (~0ul << (BITS_PER_LONG-8)))) {
350 num -= 8;
351 word <<= 8;
352 }
353 if (!(word & (~0ul << (BITS_PER_LONG-4)))) {
354 num -= 4;
355 word <<= 4;
356 }
357 if (!(word & (~0ul << (BITS_PER_LONG-2)))) {
358 num -= 2;
359 word <<= 2;
360 }
361 if (!(word & (~0ul << (BITS_PER_LONG-1))))
362 num -= 1;
363 return num;
364 }
365
366 /*
367 * __ffs - find first bit in word.
368 * @word: The word to search
369 *
370 * Returns 0..SZLONG-1
371 * Undefined if no bit exists, so code should check against 0 first.
372 */
__ffs(unsigned long word)373 static __always_inline unsigned long __ffs(unsigned long word)
374 {
375 return __fls(word & -word);
376 }
377
378 /*
379 * fls - find last bit set.
380 * @word: The word to search
381 *
382 * This is defined the same way as ffs.
383 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
384 */
fls(unsigned int x)385 static inline int fls(unsigned int x)
386 {
387 int r;
388
389 if (!__builtin_constant_p(x) &&
390 __builtin_constant_p(cpu_has_clo_clz) && cpu_has_clo_clz) {
391 __asm__(
392 " .set push \n"
393 " .set "MIPS_ISA_LEVEL" \n"
394 " clz %0, %1 \n"
395 " .set pop \n"
396 : "=r" (x)
397 : "r" (x));
398
399 return 32 - x;
400 }
401
402 r = 32;
403 if (!x)
404 return 0;
405 if (!(x & 0xffff0000u)) {
406 x <<= 16;
407 r -= 16;
408 }
409 if (!(x & 0xff000000u)) {
410 x <<= 8;
411 r -= 8;
412 }
413 if (!(x & 0xf0000000u)) {
414 x <<= 4;
415 r -= 4;
416 }
417 if (!(x & 0xc0000000u)) {
418 x <<= 2;
419 r -= 2;
420 }
421 if (!(x & 0x80000000u)) {
422 x <<= 1;
423 r -= 1;
424 }
425 return r;
426 }
427
428 #include <asm-generic/bitops/fls64.h>
429
430 /*
431 * ffs - find first bit set.
432 * @word: The word to search
433 *
434 * This is defined the same way as
435 * the libc and compiler builtin ffs routines, therefore
436 * differs in spirit from the below ffz (man ffs).
437 */
ffs(int word)438 static inline int ffs(int word)
439 {
440 if (!word)
441 return 0;
442
443 return fls(word & -word);
444 }
445
446 #include <asm-generic/bitops/ffz.h>
447
448 #ifdef __KERNEL__
449
450 #include <asm-generic/bitops/sched.h>
451
452 #include <asm/arch_hweight.h>
453 #include <asm-generic/bitops/const_hweight.h>
454
455 #include <asm-generic/bitops/le.h>
456 #include <asm-generic/bitops/ext2-atomic.h>
457
458 #endif /* __KERNEL__ */
459
460 #endif /* _ASM_BITOPS_H */
461