1 /*
2 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
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 #ifndef __ASSEMBLY__
17
18 #include <linux/types.h>
19 #include <linux/compiler.h>
20 #include <asm/barrier.h>
21 #ifndef CONFIG_ARC_HAS_LLSC
22 #include <asm/smp.h>
23 #endif
24
25 #if defined(CONFIG_ARC_HAS_LLSC)
26
27 /*
28 * Hardware assisted Atomic-R-M-W
29 */
30
31 #define BIT_OP(op, c_op, asm_op) \
32 static inline void op##_bit(unsigned long nr, volatile unsigned long *m)\
33 { \
34 unsigned int temp; \
35 \
36 m += nr >> 5; \
37 \
38 nr &= 0x1f; \
39 \
40 __asm__ __volatile__( \
41 "1: llock %0, [%1] \n" \
42 " " #asm_op " %0, %0, %2 \n" \
43 " scond %0, [%1] \n" \
44 " bnz 1b \n" \
45 : "=&r"(temp) /* Early clobber, to prevent reg reuse */ \
46 : "r"(m), /* Not "m": llock only supports reg direct addr mode */ \
47 "ir"(nr) \
48 : "cc"); \
49 }
50
51 /*
52 * Semantically:
53 * Test the bit
54 * if clear
55 * set it and return 0 (old value)
56 * else
57 * return 1 (old value).
58 *
59 * Since ARC lacks a equivalent h/w primitive, the bit is set unconditionally
60 * and the old value of bit is returned
61 */
62 #define TEST_N_BIT_OP(op, c_op, asm_op) \
63 static inline int test_and_##op##_bit(unsigned long nr, volatile unsigned long *m)\
64 { \
65 unsigned long old, temp; \
66 \
67 m += nr >> 5; \
68 \
69 nr &= 0x1f; \
70 \
71 /* \
72 * Explicit full memory barrier needed before/after as \
73 * LLOCK/SCOND themselves don't provide any such smenatic \
74 */ \
75 smp_mb(); \
76 \
77 __asm__ __volatile__( \
78 "1: llock %0, [%2] \n" \
79 " " #asm_op " %1, %0, %3 \n" \
80 " scond %1, [%2] \n" \
81 " bnz 1b \n" \
82 : "=&r"(old), "=&r"(temp) \
83 : "r"(m), "ir"(nr) \
84 : "cc"); \
85 \
86 smp_mb(); \
87 \
88 return (old & (1 << nr)) != 0; \
89 }
90
91 #else /* !CONFIG_ARC_HAS_LLSC */
92
93 /*
94 * Non hardware assisted Atomic-R-M-W
95 * Locking would change to irq-disabling only (UP) and spinlocks (SMP)
96 *
97 * There's "significant" micro-optimization in writing our own variants of
98 * bitops (over generic variants)
99 *
100 * (1) The generic APIs have "signed" @nr while we have it "unsigned"
101 * This avoids extra code to be generated for pointer arithmatic, since
102 * is "not sure" that index is NOT -ve
103 * (2) Utilize the fact that ARCompact bit fidding insn (BSET/BCLR/ASL) etc
104 * only consider bottom 5 bits of @nr, so NO need to mask them off.
105 * (GCC Quirk: however for constant @nr we still need to do the masking
106 * at compile time)
107 */
108
109 #define BIT_OP(op, c_op, asm_op) \
110 static inline void op##_bit(unsigned long nr, volatile unsigned long *m)\
111 { \
112 unsigned long temp, flags; \
113 m += nr >> 5; \
114 \
115 /* \
116 * spin lock/unlock provide the needed smp_mb() before/after \
117 */ \
118 bitops_lock(flags); \
119 \
120 temp = *m; \
121 *m = temp c_op (1UL << (nr & 0x1f)); \
122 \
123 bitops_unlock(flags); \
124 }
125
126 #define TEST_N_BIT_OP(op, c_op, asm_op) \
127 static inline int test_and_##op##_bit(unsigned long nr, volatile unsigned long *m)\
128 { \
129 unsigned long old, flags; \
130 m += nr >> 5; \
131 \
132 bitops_lock(flags); \
133 \
134 old = *m; \
135 *m = old c_op (1UL << (nr & 0x1f)); \
136 \
137 bitops_unlock(flags); \
138 \
139 return (old & (1UL << (nr & 0x1f))) != 0; \
140 }
141
142 #endif /* CONFIG_ARC_HAS_LLSC */
143
144 /***************************************
145 * Non atomic variants
146 **************************************/
147
148 #define __BIT_OP(op, c_op, asm_op) \
149 static inline void __##op##_bit(unsigned long nr, volatile unsigned long *m) \
150 { \
151 unsigned long temp; \
152 m += nr >> 5; \
153 \
154 temp = *m; \
155 *m = temp c_op (1UL << (nr & 0x1f)); \
156 }
157
158 #define __TEST_N_BIT_OP(op, c_op, asm_op) \
159 static inline int __test_and_##op##_bit(unsigned long nr, volatile unsigned long *m)\
160 { \
161 unsigned long old; \
162 m += nr >> 5; \
163 \
164 old = *m; \
165 *m = old c_op (1UL << (nr & 0x1f)); \
166 \
167 return (old & (1UL << (nr & 0x1f))) != 0; \
168 }
169
170 #define BIT_OPS(op, c_op, asm_op) \
171 \
172 /* set_bit(), clear_bit(), change_bit() */ \
173 BIT_OP(op, c_op, asm_op) \
174 \
175 /* test_and_set_bit(), test_and_clear_bit(), test_and_change_bit() */\
176 TEST_N_BIT_OP(op, c_op, asm_op) \
177 \
178 /* __set_bit(), __clear_bit(), __change_bit() */ \
179 __BIT_OP(op, c_op, asm_op) \
180 \
181 /* __test_and_set_bit(), __test_and_clear_bit(), __test_and_change_bit() */\
182 __TEST_N_BIT_OP(op, c_op, asm_op)
183
184 BIT_OPS(set, |, bset)
185 BIT_OPS(clear, & ~, bclr)
186 BIT_OPS(change, ^, bxor)
187
188 /*
189 * This routine doesn't need to be atomic.
190 */
191 static inline int
test_bit(unsigned int nr,const volatile unsigned long * addr)192 test_bit(unsigned int nr, const volatile unsigned long *addr)
193 {
194 unsigned long mask;
195
196 addr += nr >> 5;
197
198 mask = 1UL << (nr & 0x1f);
199
200 return ((mask & *addr) != 0);
201 }
202
203 #ifdef CONFIG_ISA_ARCOMPACT
204
205 /*
206 * Count the number of zeros, starting from MSB
207 * Helper for fls( ) friends
208 * This is a pure count, so (1-32) or (0-31) doesn't apply
209 * It could be 0 to 32, based on num of 0's in there
210 * clz(0x8000_0000) = 0, clz(0xFFFF_FFFF)=0, clz(0) = 32, clz(1) = 31
211 */
clz(unsigned int x)212 static inline __attribute__ ((const)) int clz(unsigned int x)
213 {
214 unsigned int res;
215
216 __asm__ __volatile__(
217 " norm.f %0, %1 \n"
218 " mov.n %0, 0 \n"
219 " add.p %0, %0, 1 \n"
220 : "=r"(res)
221 : "r"(x)
222 : "cc");
223
224 return res;
225 }
226
constant_fls(int x)227 static inline int constant_fls(int x)
228 {
229 int r = 32;
230
231 if (!x)
232 return 0;
233 if (!(x & 0xffff0000u)) {
234 x <<= 16;
235 r -= 16;
236 }
237 if (!(x & 0xff000000u)) {
238 x <<= 8;
239 r -= 8;
240 }
241 if (!(x & 0xf0000000u)) {
242 x <<= 4;
243 r -= 4;
244 }
245 if (!(x & 0xc0000000u)) {
246 x <<= 2;
247 r -= 2;
248 }
249 if (!(x & 0x80000000u)) {
250 x <<= 1;
251 r -= 1;
252 }
253 return r;
254 }
255
256 /*
257 * fls = Find Last Set in word
258 * @result: [1-32]
259 * fls(1) = 1, fls(0x80000000) = 32, fls(0) = 0
260 */
fls(unsigned long x)261 static inline __attribute__ ((const)) int fls(unsigned long x)
262 {
263 if (__builtin_constant_p(x))
264 return constant_fls(x);
265
266 return 32 - clz(x);
267 }
268
269 /*
270 * __fls: Similar to fls, but zero based (0-31)
271 */
__fls(unsigned long x)272 static inline __attribute__ ((const)) int __fls(unsigned long x)
273 {
274 if (!x)
275 return 0;
276 else
277 return fls(x) - 1;
278 }
279
280 /*
281 * ffs = Find First Set in word (LSB to MSB)
282 * @result: [1-32], 0 if all 0's
283 */
284 #define ffs(x) ({ unsigned long __t = (x); fls(__t & -__t); })
285
286 /*
287 * __ffs: Similar to ffs, but zero based (0-31)
288 */
__ffs(unsigned long word)289 static inline __attribute__ ((const)) unsigned long __ffs(unsigned long word)
290 {
291 if (!word)
292 return word;
293
294 return ffs(word) - 1;
295 }
296
297 #else /* CONFIG_ISA_ARCV2 */
298
299 /*
300 * fls = Find Last Set in word
301 * @result: [1-32]
302 * fls(1) = 1, fls(0x80000000) = 32, fls(0) = 0
303 */
fls(unsigned long x)304 static inline __attribute__ ((const)) int fls(unsigned long x)
305 {
306 int n;
307
308 asm volatile(
309 " fls.f %0, %1 \n" /* 0:31; 0(Z) if src 0 */
310 " add.nz %0, %0, 1 \n" /* 0:31 -> 1:32 */
311 : "=r"(n) /* Early clobber not needed */
312 : "r"(x)
313 : "cc");
314
315 return n;
316 }
317
318 /*
319 * __fls: Similar to fls, but zero based (0-31). Also 0 if no bit set
320 */
__fls(unsigned long x)321 static inline __attribute__ ((const)) int __fls(unsigned long x)
322 {
323 /* FLS insn has exactly same semantics as the API */
324 return __builtin_arc_fls(x);
325 }
326
327 /*
328 * ffs = Find First Set in word (LSB to MSB)
329 * @result: [1-32], 0 if all 0's
330 */
ffs(unsigned long x)331 static inline __attribute__ ((const)) int ffs(unsigned long x)
332 {
333 int n;
334
335 asm volatile(
336 " ffs.f %0, %1 \n" /* 0:31; 31(Z) if src 0 */
337 " add.nz %0, %0, 1 \n" /* 0:31 -> 1:32 */
338 " mov.z %0, 0 \n" /* 31(Z)-> 0 */
339 : "=r"(n) /* Early clobber not needed */
340 : "r"(x)
341 : "cc");
342
343 return n;
344 }
345
346 /*
347 * __ffs: Similar to ffs, but zero based (0-31)
348 */
__ffs(unsigned long x)349 static inline __attribute__ ((const)) unsigned long __ffs(unsigned long x)
350 {
351 unsigned long n;
352
353 asm volatile(
354 " ffs.f %0, %1 \n" /* 0:31; 31(Z) if src 0 */
355 " mov.z %0, 0 \n" /* 31(Z)-> 0 */
356 : "=r"(n)
357 : "r"(x)
358 : "cc");
359
360 return n;
361
362 }
363
364 #endif /* CONFIG_ISA_ARCOMPACT */
365
366 /*
367 * ffz = Find First Zero in word.
368 * @return:[0-31], 32 if all 1's
369 */
370 #define ffz(x) __ffs(~(x))
371
372 #include <asm-generic/bitops/hweight.h>
373 #include <asm-generic/bitops/fls64.h>
374 #include <asm-generic/bitops/sched.h>
375 #include <asm-generic/bitops/lock.h>
376
377 #include <asm-generic/bitops/find.h>
378 #include <asm-generic/bitops/le.h>
379 #include <asm-generic/bitops/ext2-atomic-setbit.h>
380
381 #endif /* !__ASSEMBLY__ */
382
383 #endif
384