~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/xtensa/include/asm/atomic.h

Version: ~ [ linux-5.15-rc1 ] ~ [ linux-5.14.5 ] ~ [ linux-5.13.18 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.66 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.147 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.206 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.246 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.282 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.283 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * include/asm-xtensa/atomic.h
  3  *
  4  * Atomic operations that C can't guarantee us.  Useful for resource counting..
  5  *
  6  * This file is subject to the terms and conditions of the GNU General Public
  7  * License.  See the file "COPYING" in the main directory of this archive
  8  * for more details.
  9  *
 10  * Copyright (C) 2001 - 2008 Tensilica Inc.
 11  */
 12 
 13 #ifndef _XTENSA_ATOMIC_H
 14 #define _XTENSA_ATOMIC_H
 15 
 16 #include <linux/stringify.h>
 17 #include <linux/types.h>
 18 
 19 #ifdef __KERNEL__
 20 #include <asm/processor.h>
 21 #include <asm/cmpxchg.h>
 22 #include <asm/barrier.h>
 23 
 24 #define ATOMIC_INIT(i)  { (i) }
 25 
 26 /*
 27  * This Xtensa implementation assumes that the right mechanism
 28  * for exclusion is for locking interrupts to level EXCM_LEVEL.
 29  *
 30  * Locking interrupts looks like this:
 31  *
 32  *    rsil a15, TOPLEVEL
 33  *    <code>
 34  *    wsr  a15, PS
 35  *    rsync
 36  *
 37  * Note that a15 is used here because the register allocation
 38  * done by the compiler is not guaranteed and a window overflow
 39  * may not occur between the rsil and wsr instructions. By using
 40  * a15 in the rsil, the machine is guaranteed to be in a state
 41  * where no register reference will cause an overflow.
 42  */
 43 
 44 /**
 45  * atomic_read - read atomic variable
 46  * @v: pointer of type atomic_t
 47  *
 48  * Atomically reads the value of @v.
 49  */
 50 #define atomic_read(v)          READ_ONCE((v)->counter)
 51 
 52 /**
 53  * atomic_set - set atomic variable
 54  * @v: pointer of type atomic_t
 55  * @i: required value
 56  *
 57  * Atomically sets the value of @v to @i.
 58  */
 59 #define atomic_set(v,i)         WRITE_ONCE((v)->counter, (i))
 60 
 61 #if XCHAL_HAVE_S32C1I
 62 #define ATOMIC_OP(op)                                                   \
 63 static inline void atomic_##op(int i, atomic_t * v)                     \
 64 {                                                                       \
 65         unsigned long tmp;                                              \
 66         int result;                                                     \
 67                                                                         \
 68         __asm__ __volatile__(                                           \
 69                         "1:     l32i    %1, %3, 0\n"                    \
 70                         "       wsr     %1, scompare1\n"                \
 71                         "       " #op " %0, %1, %2\n"                   \
 72                         "       s32c1i  %0, %3, 0\n"                    \
 73                         "       bne     %0, %1, 1b\n"                   \
 74                         : "=&a" (result), "=&a" (tmp)                   \
 75                         : "a" (i), "a" (v)                              \
 76                         : "memory"                                      \
 77                         );                                              \
 78 }                                                                       \
 79 
 80 #define ATOMIC_OP_RETURN(op)                                            \
 81 static inline int atomic_##op##_return(int i, atomic_t * v)             \
 82 {                                                                       \
 83         unsigned long tmp;                                              \
 84         int result;                                                     \
 85                                                                         \
 86         __asm__ __volatile__(                                           \
 87                         "1:     l32i    %1, %3, 0\n"                    \
 88                         "       wsr     %1, scompare1\n"                \
 89                         "       " #op " %0, %1, %2\n"                   \
 90                         "       s32c1i  %0, %3, 0\n"                    \
 91                         "       bne     %0, %1, 1b\n"                   \
 92                         "       " #op " %0, %0, %2\n"                   \
 93                         : "=&a" (result), "=&a" (tmp)                   \
 94                         : "a" (i), "a" (v)                              \
 95                         : "memory"                                      \
 96                         );                                              \
 97                                                                         \
 98         return result;                                                  \
 99 }
100 
101 #define ATOMIC_FETCH_OP(op)                                             \
102 static inline int atomic_fetch_##op(int i, atomic_t * v)                \
103 {                                                                       \
104         unsigned long tmp;                                              \
105         int result;                                                     \
106                                                                         \
107         __asm__ __volatile__(                                           \
108                         "1:     l32i    %1, %3, 0\n"                    \
109                         "       wsr     %1, scompare1\n"                \
110                         "       " #op " %0, %1, %2\n"                   \
111                         "       s32c1i  %0, %3, 0\n"                    \
112                         "       bne     %0, %1, 1b\n"                   \
113                         : "=&a" (result), "=&a" (tmp)                   \
114                         : "a" (i), "a" (v)                              \
115                         : "memory"                                      \
116                         );                                              \
117                                                                         \
118         return result;                                                  \
119 }
120 
121 #else /* XCHAL_HAVE_S32C1I */
122 
123 #define ATOMIC_OP(op)                                                   \
124 static inline void atomic_##op(int i, atomic_t * v)                     \
125 {                                                                       \
126         unsigned int vval;                                              \
127                                                                         \
128         __asm__ __volatile__(                                           \
129                         "       rsil    a15, "__stringify(TOPLEVEL)"\n"\
130                         "       l32i    %0, %2, 0\n"                    \
131                         "       " #op " %0, %0, %1\n"                   \
132                         "       s32i    %0, %2, 0\n"                    \
133                         "       wsr     a15, ps\n"                      \
134                         "       rsync\n"                                \
135                         : "=&a" (vval)                                  \
136                         : "a" (i), "a" (v)                              \
137                         : "a15", "memory"                               \
138                         );                                              \
139 }                                                                       \
140 
141 #define ATOMIC_OP_RETURN(op)                                            \
142 static inline int atomic_##op##_return(int i, atomic_t * v)             \
143 {                                                                       \
144         unsigned int vval;                                              \
145                                                                         \
146         __asm__ __volatile__(                                           \
147                         "       rsil    a15,"__stringify(TOPLEVEL)"\n"  \
148                         "       l32i    %0, %2, 0\n"                    \
149                         "       " #op " %0, %0, %1\n"                   \
150                         "       s32i    %0, %2, 0\n"                    \
151                         "       wsr     a15, ps\n"                      \
152                         "       rsync\n"                                \
153                         : "=&a" (vval)                                  \
154                         : "a" (i), "a" (v)                              \
155                         : "a15", "memory"                               \
156                         );                                              \
157                                                                         \
158         return vval;                                                    \
159 }
160 
161 #define ATOMIC_FETCH_OP(op)                                             \
162 static inline int atomic_fetch_##op(int i, atomic_t * v)                \
163 {                                                                       \
164         unsigned int tmp, vval;                                         \
165                                                                         \
166         __asm__ __volatile__(                                           \
167                         "       rsil    a15,"__stringify(TOPLEVEL)"\n"  \
168                         "       l32i    %0, %3, 0\n"                    \
169                         "       " #op " %1, %0, %2\n"                   \
170                         "       s32i    %1, %3, 0\n"                    \
171                         "       wsr     a15, ps\n"                      \
172                         "       rsync\n"                                \
173                         : "=&a" (vval), "=&a" (tmp)                     \
174                         : "a" (i), "a" (v)                              \
175                         : "a15", "memory"                               \
176                         );                                              \
177                                                                         \
178         return vval;                                                    \
179 }
180 
181 #endif /* XCHAL_HAVE_S32C1I */
182 
183 #define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_FETCH_OP(op) ATOMIC_OP_RETURN(op)
184 
185 ATOMIC_OPS(add)
186 ATOMIC_OPS(sub)
187 
188 #undef ATOMIC_OPS
189 #define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_FETCH_OP(op)
190 
191 ATOMIC_OPS(and)
192 ATOMIC_OPS(or)
193 ATOMIC_OPS(xor)
194 
195 #undef ATOMIC_OPS
196 #undef ATOMIC_FETCH_OP
197 #undef ATOMIC_OP_RETURN
198 #undef ATOMIC_OP
199 
200 /**
201  * atomic_sub_and_test - subtract value from variable and test result
202  * @i: integer value to subtract
203  * @v: pointer of type atomic_t
204  *
205  * Atomically subtracts @i from @v and returns
206  * true if the result is zero, or false for all
207  * other cases.
208  */
209 #define atomic_sub_and_test(i,v) (atomic_sub_return((i),(v)) == 0)
210 
211 /**
212  * atomic_inc - increment atomic variable
213  * @v: pointer of type atomic_t
214  *
215  * Atomically increments @v by 1.
216  */
217 #define atomic_inc(v) atomic_add(1,(v))
218 
219 /**
220  * atomic_inc - increment atomic variable
221  * @v: pointer of type atomic_t
222  *
223  * Atomically increments @v by 1.
224  */
225 #define atomic_inc_return(v) atomic_add_return(1,(v))
226 
227 /**
228  * atomic_dec - decrement atomic variable
229  * @v: pointer of type atomic_t
230  *
231  * Atomically decrements @v by 1.
232  */
233 #define atomic_dec(v) atomic_sub(1,(v))
234 
235 /**
236  * atomic_dec_return - decrement atomic variable
237  * @v: pointer of type atomic_t
238  *
239  * Atomically decrements @v by 1.
240  */
241 #define atomic_dec_return(v) atomic_sub_return(1,(v))
242 
243 /**
244  * atomic_dec_and_test - decrement and test
245  * @v: pointer of type atomic_t
246  *
247  * Atomically decrements @v by 1 and
248  * returns true if the result is 0, or false for all other
249  * cases.
250  */
251 #define atomic_dec_and_test(v) (atomic_sub_return(1,(v)) == 0)
252 
253 /**
254  * atomic_inc_and_test - increment and test
255  * @v: pointer of type atomic_t
256  *
257  * Atomically increments @v by 1
258  * and returns true if the result is zero, or false for all
259  * other cases.
260  */
261 #define atomic_inc_and_test(v) (atomic_add_return(1,(v)) == 0)
262 
263 /**
264  * atomic_add_negative - add and test if negative
265  * @v: pointer of type atomic_t
266  * @i: integer value to add
267  *
268  * Atomically adds @i to @v and returns true
269  * if the result is negative, or false when
270  * result is greater than or equal to zero.
271  */
272 #define atomic_add_negative(i,v) (atomic_add_return((i),(v)) < 0)
273 
274 #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
275 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
276 
277 /**
278  * __atomic_add_unless - add unless the number is a given value
279  * @v: pointer of type atomic_t
280  * @a: the amount to add to v...
281  * @u: ...unless v is equal to u.
282  *
283  * Atomically adds @a to @v, so long as it was not @u.
284  * Returns the old value of @v.
285  */
286 static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
287 {
288         int c, old;
289         c = atomic_read(v);
290         for (;;) {
291                 if (unlikely(c == (u)))
292                         break;
293                 old = atomic_cmpxchg((v), c, c + (a));
294                 if (likely(old == c))
295                         break;
296                 c = old;
297         }
298         return c;
299 }
300 
301 #endif /* __KERNEL__ */
302 
303 #endif /* _XTENSA_ATOMIC_H */
304 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp