1 #ifndef _ASM_M32R_ATOMIC_H
2 #define _ASM_M32R_ATOMIC_H
3
4 /*
5 * linux/include/asm-m32r/atomic.h
6 *
7 * M32R version:
8 * Copyright (C) 2001, 2002 Hitoshi Yamamoto
9 * Copyright (C) 2004 Hirokazu Takata <takata at linux-m32r.org>
10 */
11
12 #include <linux/types.h>
13 #include <asm/assembler.h>
14 #include <asm/cmpxchg.h>
15 #include <asm/dcache_clear.h>
16 #include <asm/barrier.h>
17
18 /*
19 * Atomic operations that C can't guarantee us. Useful for
20 * resource counting etc..
21 */
22
23 #define ATOMIC_INIT(i) { (i) }
24
25 /**
26 * atomic_read - read atomic variable
27 * @v: pointer of type atomic_t
28 *
29 * Atomically reads the value of @v.
30 */
31 #define atomic_read(v) READ_ONCE((v)->counter)
32
33 /**
34 * atomic_set - set atomic variable
35 * @v: pointer of type atomic_t
36 * @i: required value
37 *
38 * Atomically sets the value of @v to @i.
39 */
40 #define atomic_set(v,i) WRITE_ONCE(((v)->counter), (i))
41
42 #ifdef CONFIG_CHIP_M32700_TS1
43 #define __ATOMIC_CLOBBER , "r4"
44 #else
45 #define __ATOMIC_CLOBBER
46 #endif
47
48 #define ATOMIC_OP(op) \
49 static __inline__ void atomic_##op(int i, atomic_t *v) \
50 { \
51 unsigned long flags; \
52 int result; \
53 \
54 local_irq_save(flags); \
55 __asm__ __volatile__ ( \
56 "# atomic_" #op " \n\t" \
57 DCACHE_CLEAR("%0", "r4", "%1") \
58 M32R_LOCK" %0, @%1; \n\t" \
59 #op " %0, %2; \n\t" \
60 M32R_UNLOCK" %0, @%1; \n\t" \
61 : "=&r" (result) \
62 : "r" (&v->counter), "r" (i) \
63 : "memory" \
64 __ATOMIC_CLOBBER \
65 ); \
66 local_irq_restore(flags); \
67 } \
68
69 #define ATOMIC_OP_RETURN(op) \
70 static __inline__ int atomic_##op##_return(int i, atomic_t *v) \
71 { \
72 unsigned long flags; \
73 int result; \
74 \
75 local_irq_save(flags); \
76 __asm__ __volatile__ ( \
77 "# atomic_" #op "_return \n\t" \
78 DCACHE_CLEAR("%0", "r4", "%1") \
79 M32R_LOCK" %0, @%1; \n\t" \
80 #op " %0, %2; \n\t" \
81 M32R_UNLOCK" %0, @%1; \n\t" \
82 : "=&r" (result) \
83 : "r" (&v->counter), "r" (i) \
84 : "memory" \
85 __ATOMIC_CLOBBER \
86 ); \
87 local_irq_restore(flags); \
88 \
89 return result; \
90 }
91
92 #define ATOMIC_FETCH_OP(op) \
93 static __inline__ int atomic_fetch_##op(int i, atomic_t *v) \
94 { \
95 unsigned long flags; \
96 int result, val; \
97 \
98 local_irq_save(flags); \
99 __asm__ __volatile__ ( \
100 "# atomic_fetch_" #op " \n\t" \
101 DCACHE_CLEAR("%0", "r4", "%2") \
102 M32R_LOCK" %1, @%2; \n\t" \
103 "mv %0, %1 \n\t" \
104 #op " %1, %3; \n\t" \
105 M32R_UNLOCK" %1, @%2; \n\t" \
106 : "=&r" (result), "=&r" (val) \
107 : "r" (&v->counter), "r" (i) \
108 : "memory" \
109 __ATOMIC_CLOBBER \
110 ); \
111 local_irq_restore(flags); \
112 \
113 return result; \
114 }
115
116 #define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op) ATOMIC_FETCH_OP(op)
117
118 ATOMIC_OPS(add)
ATOMIC_OPS(sub)119 ATOMIC_OPS(sub)
120
121 #undef ATOMIC_OPS
122 #define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_FETCH_OP(op)
123
124 ATOMIC_OPS(and)
125 ATOMIC_OPS(or)
126 ATOMIC_OPS(xor)
127
128 #undef ATOMIC_OPS
129 #undef ATOMIC_FETCH_OP
130 #undef ATOMIC_OP_RETURN
131 #undef ATOMIC_OP
132
133 /**
134 * atomic_sub_and_test - subtract value from variable and test result
135 * @i: integer value to subtract
136 * @v: pointer of type atomic_t
137 *
138 * Atomically subtracts @i from @v and returns
139 * true if the result is zero, or false for all
140 * other cases.
141 */
142 #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
143
144 /**
145 * atomic_inc_return - increment atomic variable and return it
146 * @v: pointer of type atomic_t
147 *
148 * Atomically increments @v by 1 and returns the result.
149 */
150 static __inline__ int atomic_inc_return(atomic_t *v)
151 {
152 unsigned long flags;
153 int result;
154
155 local_irq_save(flags);
156 __asm__ __volatile__ (
157 "# atomic_inc_return \n\t"
158 DCACHE_CLEAR("%0", "r4", "%1")
159 M32R_LOCK" %0, @%1; \n\t"
160 "addi %0, #1; \n\t"
161 M32R_UNLOCK" %0, @%1; \n\t"
162 : "=&r" (result)
163 : "r" (&v->counter)
164 : "memory"
165 __ATOMIC_CLOBBER
166 );
167 local_irq_restore(flags);
168
169 return result;
170 }
171
172 /**
173 * atomic_dec_return - decrement atomic variable and return it
174 * @v: pointer of type atomic_t
175 *
176 * Atomically decrements @v by 1 and returns the result.
177 */
atomic_dec_return(atomic_t * v)178 static __inline__ int atomic_dec_return(atomic_t *v)
179 {
180 unsigned long flags;
181 int result;
182
183 local_irq_save(flags);
184 __asm__ __volatile__ (
185 "# atomic_dec_return \n\t"
186 DCACHE_CLEAR("%0", "r4", "%1")
187 M32R_LOCK" %0, @%1; \n\t"
188 "addi %0, #-1; \n\t"
189 M32R_UNLOCK" %0, @%1; \n\t"
190 : "=&r" (result)
191 : "r" (&v->counter)
192 : "memory"
193 __ATOMIC_CLOBBER
194 );
195 local_irq_restore(flags);
196
197 return result;
198 }
199
200 /**
201 * atomic_inc - increment atomic variable
202 * @v: pointer of type atomic_t
203 *
204 * Atomically increments @v by 1.
205 */
206 #define atomic_inc(v) ((void)atomic_inc_return(v))
207
208 /**
209 * atomic_dec - decrement atomic variable
210 * @v: pointer of type atomic_t
211 *
212 * Atomically decrements @v by 1.
213 */
214 #define atomic_dec(v) ((void)atomic_dec_return(v))
215
216 /**
217 * atomic_inc_and_test - increment and test
218 * @v: pointer of type atomic_t
219 *
220 * Atomically increments @v by 1
221 * and returns true if the result is zero, or false for all
222 * other cases.
223 */
224 #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
225
226 /**
227 * atomic_dec_and_test - decrement and test
228 * @v: pointer of type atomic_t
229 *
230 * Atomically decrements @v by 1 and
231 * returns true if the result is 0, or false for all
232 * other cases.
233 */
234 #define atomic_dec_and_test(v) (atomic_dec_return(v) == 0)
235
236 /**
237 * atomic_add_negative - add and test if negative
238 * @v: pointer of type atomic_t
239 * @i: integer value to add
240 *
241 * Atomically adds @i to @v and returns true
242 * if the result is negative, or false when
243 * result is greater than or equal to zero.
244 */
245 #define atomic_add_negative(i,v) (atomic_add_return((i), (v)) < 0)
246
247 #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
248 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
249
250 /**
251 * __atomic_add_unless - add unless the number is a given value
252 * @v: pointer of type atomic_t
253 * @a: the amount to add to v...
254 * @u: ...unless v is equal to u.
255 *
256 * Atomically adds @a to @v, so long as it was not @u.
257 * Returns the old value of @v.
258 */
__atomic_add_unless(atomic_t * v,int a,int u)259 static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
260 {
261 int c, old;
262 c = atomic_read(v);
263 for (;;) {
264 if (unlikely(c == (u)))
265 break;
266 old = atomic_cmpxchg((v), c, c + (a));
267 if (likely(old == c))
268 break;
269 c = old;
270 }
271 return c;
272 }
273
274 #endif /* _ASM_M32R_ATOMIC_H */
275