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_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op)
93
94 ATOMIC_OPS(add)
ATOMIC_OPS(sub)95 ATOMIC_OPS(sub)
96
97 ATOMIC_OP(and)
98 ATOMIC_OP(or)
99 ATOMIC_OP(xor)
100
101 #undef ATOMIC_OPS
102 #undef ATOMIC_OP_RETURN
103 #undef ATOMIC_OP
104
105 /**
106 * atomic_sub_and_test - subtract value from variable and test result
107 * @i: integer value to subtract
108 * @v: pointer of type atomic_t
109 *
110 * Atomically subtracts @i from @v and returns
111 * true if the result is zero, or false for all
112 * other cases.
113 */
114 #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
115
116 /**
117 * atomic_inc_return - increment atomic variable and return it
118 * @v: pointer of type atomic_t
119 *
120 * Atomically increments @v by 1 and returns the result.
121 */
122 static __inline__ int atomic_inc_return(atomic_t *v)
123 {
124 unsigned long flags;
125 int result;
126
127 local_irq_save(flags);
128 __asm__ __volatile__ (
129 "# atomic_inc_return \n\t"
130 DCACHE_CLEAR("%0", "r4", "%1")
131 M32R_LOCK" %0, @%1; \n\t"
132 "addi %0, #1; \n\t"
133 M32R_UNLOCK" %0, @%1; \n\t"
134 : "=&r" (result)
135 : "r" (&v->counter)
136 : "memory"
137 __ATOMIC_CLOBBER
138 );
139 local_irq_restore(flags);
140
141 return result;
142 }
143
144 /**
145 * atomic_dec_return - decrement atomic variable and return it
146 * @v: pointer of type atomic_t
147 *
148 * Atomically decrements @v by 1 and returns the result.
149 */
atomic_dec_return(atomic_t * v)150 static __inline__ int atomic_dec_return(atomic_t *v)
151 {
152 unsigned long flags;
153 int result;
154
155 local_irq_save(flags);
156 __asm__ __volatile__ (
157 "# atomic_dec_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_inc - increment atomic variable
174 * @v: pointer of type atomic_t
175 *
176 * Atomically increments @v by 1.
177 */
178 #define atomic_inc(v) ((void)atomic_inc_return(v))
179
180 /**
181 * atomic_dec - decrement atomic variable
182 * @v: pointer of type atomic_t
183 *
184 * Atomically decrements @v by 1.
185 */
186 #define atomic_dec(v) ((void)atomic_dec_return(v))
187
188 /**
189 * atomic_inc_and_test - increment and test
190 * @v: pointer of type atomic_t
191 *
192 * Atomically increments @v by 1
193 * and returns true if the result is zero, or false for all
194 * other cases.
195 */
196 #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
197
198 /**
199 * atomic_dec_and_test - decrement and test
200 * @v: pointer of type atomic_t
201 *
202 * Atomically decrements @v by 1 and
203 * returns true if the result is 0, or false for all
204 * other cases.
205 */
206 #define atomic_dec_and_test(v) (atomic_dec_return(v) == 0)
207
208 /**
209 * atomic_add_negative - add and test if negative
210 * @v: pointer of type atomic_t
211 * @i: integer value to add
212 *
213 * Atomically adds @i to @v and returns true
214 * if the result is negative, or false when
215 * result is greater than or equal to zero.
216 */
217 #define atomic_add_negative(i,v) (atomic_add_return((i), (v)) < 0)
218
219 #define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
220 #define atomic_xchg(v, new) (xchg(&((v)->counter), new))
221
222 /**
223 * __atomic_add_unless - add unless the number is a given value
224 * @v: pointer of type atomic_t
225 * @a: the amount to add to v...
226 * @u: ...unless v is equal to u.
227 *
228 * Atomically adds @a to @v, so long as it was not @u.
229 * Returns the old value of @v.
230 */
__atomic_add_unless(atomic_t * v,int a,int u)231 static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
232 {
233 int c, old;
234 c = atomic_read(v);
235 for (;;) {
236 if (unlikely(c == (u)))
237 break;
238 old = atomic_cmpxchg((v), c, c + (a));
239 if (likely(old == c))
240 break;
241 c = old;
242 }
243 return c;
244 }
245
246 #endif /* _ASM_M32R_ATOMIC_H */
247