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1/*
2 * Atomic operations that C can't guarantee us. Useful for
3 * resource counting etc..
4 *
5 * But use these as seldom as possible since they are much more slower
6 * than regular operations.
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file "COPYING" in the main directory of this archive
10 * for more details.
11 *
12 * Copyright (C) 1996, 97, 99, 2000, 03, 04, 06 by Ralf Baechle
13 */
14#ifndef _ASM_ATOMIC_H
15#define _ASM_ATOMIC_H
16
17#include <linux/irqflags.h>
18#include <linux/types.h>
19#include <asm/barrier.h>
20#include <asm/compiler.h>
21#include <asm/cpu-features.h>
22#include <asm/cmpxchg.h>
23#include <asm/llsc.h>
24#include <asm/sync.h>
25#include <asm/war.h>
26
27#define ATOMIC_OPS(pfx, type) \
28static __always_inline type pfx##_read(const pfx##_t *v) \
29{ \
30 return READ_ONCE(v->counter); \
31} \
32 \
33static __always_inline void pfx##_set(pfx##_t *v, type i) \
34{ \
35 WRITE_ONCE(v->counter, i); \
36} \
37 \
38static __always_inline type pfx##_cmpxchg(pfx##_t *v, type o, type n) \
39{ \
40 return cmpxchg(&v->counter, o, n); \
41} \
42 \
43static __always_inline type pfx##_xchg(pfx##_t *v, type n) \
44{ \
45 return xchg(&v->counter, n); \
46}
47
48ATOMIC_OPS(atomic, int)
49
50#ifdef CONFIG_64BIT
51# define ATOMIC64_INIT(i) { (i) }
52ATOMIC_OPS(atomic64, s64)
53#endif
54
55#define ATOMIC_OP(pfx, op, type, c_op, asm_op, ll, sc) \
56static __inline__ void pfx##_##op(type i, pfx##_t * v) \
57{ \
58 type temp; \
59 \
60 if (!kernel_uses_llsc) { \
61 unsigned long flags; \
62 \
63 raw_local_irq_save(flags); \
64 v->counter c_op i; \
65 raw_local_irq_restore(flags); \
66 return; \
67 } \
68 \
69 __asm__ __volatile__( \
70 " .set push \n" \
71 " .set " MIPS_ISA_LEVEL " \n" \
72 " " __SYNC(full, loongson3_war) " \n" \
73 "1: " #ll " %0, %1 # " #pfx "_" #op " \n" \
74 " " #asm_op " %0, %2 \n" \
75 " " #sc " %0, %1 \n" \
76 "\t" __SC_BEQZ "%0, 1b \n" \
77 " .set pop \n" \
78 : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
79 : "Ir" (i) : __LLSC_CLOBBER); \
80}
81
82#define ATOMIC_OP_RETURN(pfx, op, type, c_op, asm_op, ll, sc) \
83static __inline__ type pfx##_##op##_return_relaxed(type i, pfx##_t * v) \
84{ \
85 type temp, result; \
86 \
87 if (!kernel_uses_llsc) { \
88 unsigned long flags; \
89 \
90 raw_local_irq_save(flags); \
91 result = v->counter; \
92 result c_op i; \
93 v->counter = result; \
94 raw_local_irq_restore(flags); \
95 return result; \
96 } \
97 \
98 __asm__ __volatile__( \
99 " .set push \n" \
100 " .set " MIPS_ISA_LEVEL " \n" \
101 " " __SYNC(full, loongson3_war) " \n" \
102 "1: " #ll " %1, %2 # " #pfx "_" #op "_return\n" \
103 " " #asm_op " %0, %1, %3 \n" \
104 " " #sc " %0, %2 \n" \
105 "\t" __SC_BEQZ "%0, 1b \n" \
106 " " #asm_op " %0, %1, %3 \n" \
107 " .set pop \n" \
108 : "=&r" (result), "=&r" (temp), \
109 "+" GCC_OFF_SMALL_ASM() (v->counter) \
110 : "Ir" (i) : __LLSC_CLOBBER); \
111 \
112 return result; \
113}
114
115#define ATOMIC_FETCH_OP(pfx, op, type, c_op, asm_op, ll, sc) \
116static __inline__ type pfx##_fetch_##op##_relaxed(type i, pfx##_t * v) \
117{ \
118 int temp, result; \
119 \
120 if (!kernel_uses_llsc) { \
121 unsigned long flags; \
122 \
123 raw_local_irq_save(flags); \
124 result = v->counter; \
125 v->counter c_op i; \
126 raw_local_irq_restore(flags); \
127 return result; \
128 } \
129 \
130 __asm__ __volatile__( \
131 " .set push \n" \
132 " .set " MIPS_ISA_LEVEL " \n" \
133 " " __SYNC(full, loongson3_war) " \n" \
134 "1: " #ll " %1, %2 # " #pfx "_fetch_" #op "\n" \
135 " " #asm_op " %0, %1, %3 \n" \
136 " " #sc " %0, %2 \n" \
137 "\t" __SC_BEQZ "%0, 1b \n" \
138 " .set pop \n" \
139 " move %0, %1 \n" \
140 : "=&r" (result), "=&r" (temp), \
141 "+" GCC_OFF_SMALL_ASM() (v->counter) \
142 : "Ir" (i) : __LLSC_CLOBBER); \
143 \
144 return result; \
145}
146
147#undef ATOMIC_OPS
148#define ATOMIC_OPS(pfx, op, type, c_op, asm_op, ll, sc) \
149 ATOMIC_OP(pfx, op, type, c_op, asm_op, ll, sc) \
150 ATOMIC_OP_RETURN(pfx, op, type, c_op, asm_op, ll, sc) \
151 ATOMIC_FETCH_OP(pfx, op, type, c_op, asm_op, ll, sc)
152
153ATOMIC_OPS(atomic, add, int, +=, addu, ll, sc)
154ATOMIC_OPS(atomic, sub, int, -=, subu, ll, sc)
155
156#define atomic_add_return_relaxed atomic_add_return_relaxed
157#define atomic_sub_return_relaxed atomic_sub_return_relaxed
158#define atomic_fetch_add_relaxed atomic_fetch_add_relaxed
159#define atomic_fetch_sub_relaxed atomic_fetch_sub_relaxed
160
161#ifdef CONFIG_64BIT
162ATOMIC_OPS(atomic64, add, s64, +=, daddu, lld, scd)
163ATOMIC_OPS(atomic64, sub, s64, -=, dsubu, lld, scd)
164# define atomic64_add_return_relaxed atomic64_add_return_relaxed
165# define atomic64_sub_return_relaxed atomic64_sub_return_relaxed
166# define atomic64_fetch_add_relaxed atomic64_fetch_add_relaxed
167# define atomic64_fetch_sub_relaxed atomic64_fetch_sub_relaxed
168#endif /* CONFIG_64BIT */
169
170#undef ATOMIC_OPS
171#define ATOMIC_OPS(pfx, op, type, c_op, asm_op, ll, sc) \
172 ATOMIC_OP(pfx, op, type, c_op, asm_op, ll, sc) \
173 ATOMIC_FETCH_OP(pfx, op, type, c_op, asm_op, ll, sc)
174
175ATOMIC_OPS(atomic, and, int, &=, and, ll, sc)
176ATOMIC_OPS(atomic, or, int, |=, or, ll, sc)
177ATOMIC_OPS(atomic, xor, int, ^=, xor, ll, sc)
178
179#define atomic_fetch_and_relaxed atomic_fetch_and_relaxed
180#define atomic_fetch_or_relaxed atomic_fetch_or_relaxed
181#define atomic_fetch_xor_relaxed atomic_fetch_xor_relaxed
182
183#ifdef CONFIG_64BIT
184ATOMIC_OPS(atomic64, and, s64, &=, and, lld, scd)
185ATOMIC_OPS(atomic64, or, s64, |=, or, lld, scd)
186ATOMIC_OPS(atomic64, xor, s64, ^=, xor, lld, scd)
187# define atomic64_fetch_and_relaxed atomic64_fetch_and_relaxed
188# define atomic64_fetch_or_relaxed atomic64_fetch_or_relaxed
189# define atomic64_fetch_xor_relaxed atomic64_fetch_xor_relaxed
190#endif
191
192#undef ATOMIC_OPS
193#undef ATOMIC_FETCH_OP
194#undef ATOMIC_OP_RETURN
195#undef ATOMIC_OP
196
197/*
198 * atomic_sub_if_positive - conditionally subtract integer from atomic variable
199 * @i: integer value to subtract
200 * @v: pointer of type atomic_t
201 *
202 * Atomically test @v and subtract @i if @v is greater or equal than @i.
203 * The function returns the old value of @v minus @i.
204 */
205#define ATOMIC_SIP_OP(pfx, type, op, ll, sc) \
206static __inline__ int pfx##_sub_if_positive(type i, pfx##_t * v) \
207{ \
208 type temp, result; \
209 \
210 smp_mb__before_atomic(); \
211 \
212 if (!kernel_uses_llsc) { \
213 unsigned long flags; \
214 \
215 raw_local_irq_save(flags); \
216 result = v->counter; \
217 result -= i; \
218 if (result >= 0) \
219 v->counter = result; \
220 raw_local_irq_restore(flags); \
221 smp_mb__after_atomic(); \
222 return result; \
223 } \
224 \
225 __asm__ __volatile__( \
226 " .set push \n" \
227 " .set " MIPS_ISA_LEVEL " \n" \
228 " " __SYNC(full, loongson3_war) " \n" \
229 "1: " #ll " %1, %2 # atomic_sub_if_positive\n" \
230 " .set pop \n" \
231 " " #op " %0, %1, %3 \n" \
232 " move %1, %0 \n" \
233 " bltz %0, 2f \n" \
234 " .set push \n" \
235 " .set " MIPS_ISA_LEVEL " \n" \
236 " " #sc " %1, %2 \n" \
237 " " __SC_BEQZ "%1, 1b \n" \
238 "2: " __SYNC(full, loongson3_war) " \n" \
239 " .set pop \n" \
240 : "=&r" (result), "=&r" (temp), \
241 "+" GCC_OFF_SMALL_ASM() (v->counter) \
242 : "Ir" (i) \
243 : __LLSC_CLOBBER); \
244 \
245 /* \
246 * In the Loongson3 workaround case we already have a \
247 * completion barrier at 2: above, which is needed due to the \
248 * bltz that can branch to code outside of the LL/SC loop. As \
249 * such, we don't need to emit another barrier here. \
250 */ \
251 if (!__SYNC_loongson3_war) \
252 smp_mb__after_atomic(); \
253 \
254 return result; \
255}
256
257ATOMIC_SIP_OP(atomic, int, subu, ll, sc)
258#define atomic_dec_if_positive(v) atomic_sub_if_positive(1, v)
259
260#ifdef CONFIG_64BIT
261ATOMIC_SIP_OP(atomic64, s64, dsubu, lld, scd)
262#define atomic64_dec_if_positive(v) atomic64_sub_if_positive(1, v)
263#endif
264
265#undef ATOMIC_SIP_OP
266
267#endif /* _ASM_ATOMIC_H */
1/*
2 * Atomic operations that C can't guarantee us. Useful for
3 * resource counting etc..
4 *
5 * But use these as seldom as possible since they are much more slower
6 * than regular operations.
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file "COPYING" in the main directory of this archive
10 * for more details.
11 *
12 * Copyright (C) 1996, 97, 99, 2000, 03, 04, 06 by Ralf Baechle
13 */
14#ifndef _ASM_ATOMIC_H
15#define _ASM_ATOMIC_H
16
17#include <linux/irqflags.h>
18#include <linux/types.h>
19#include <asm/barrier.h>
20#include <asm/compiler.h>
21#include <asm/cpu-features.h>
22#include <asm/cmpxchg.h>
23#include <asm/war.h>
24
25#define ATOMIC_INIT(i) { (i) }
26
27/*
28 * atomic_read - read atomic variable
29 * @v: pointer of type atomic_t
30 *
31 * Atomically reads the value of @v.
32 */
33#define atomic_read(v) READ_ONCE((v)->counter)
34
35/*
36 * atomic_set - set atomic variable
37 * @v: pointer of type atomic_t
38 * @i: required value
39 *
40 * Atomically sets the value of @v to @i.
41 */
42#define atomic_set(v, i) WRITE_ONCE((v)->counter, (i))
43
44#define ATOMIC_OP(op, c_op, asm_op) \
45static __inline__ void atomic_##op(int i, atomic_t * v) \
46{ \
47 if (kernel_uses_llsc && R10000_LLSC_WAR) { \
48 int temp; \
49 \
50 __asm__ __volatile__( \
51 " .set arch=r4000 \n" \
52 "1: ll %0, %1 # atomic_" #op " \n" \
53 " " #asm_op " %0, %2 \n" \
54 " sc %0, %1 \n" \
55 " beqzl %0, 1b \n" \
56 " .set mips0 \n" \
57 : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
58 : "Ir" (i)); \
59 } else if (kernel_uses_llsc) { \
60 int temp; \
61 \
62 do { \
63 __asm__ __volatile__( \
64 " .set "MIPS_ISA_LEVEL" \n" \
65 " ll %0, %1 # atomic_" #op "\n" \
66 " " #asm_op " %0, %2 \n" \
67 " sc %0, %1 \n" \
68 " .set mips0 \n" \
69 : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
70 : "Ir" (i)); \
71 } while (unlikely(!temp)); \
72 } else { \
73 unsigned long flags; \
74 \
75 raw_local_irq_save(flags); \
76 v->counter c_op i; \
77 raw_local_irq_restore(flags); \
78 } \
79}
80
81#define ATOMIC_OP_RETURN(op, c_op, asm_op) \
82static __inline__ int atomic_##op##_return(int i, atomic_t * v) \
83{ \
84 int result; \
85 \
86 smp_mb__before_llsc(); \
87 \
88 if (kernel_uses_llsc && R10000_LLSC_WAR) { \
89 int temp; \
90 \
91 __asm__ __volatile__( \
92 " .set arch=r4000 \n" \
93 "1: ll %1, %2 # atomic_" #op "_return \n" \
94 " " #asm_op " %0, %1, %3 \n" \
95 " sc %0, %2 \n" \
96 " beqzl %0, 1b \n" \
97 " " #asm_op " %0, %1, %3 \n" \
98 " .set mips0 \n" \
99 : "=&r" (result), "=&r" (temp), \
100 "+" GCC_OFF_SMALL_ASM() (v->counter) \
101 : "Ir" (i)); \
102 } else if (kernel_uses_llsc) { \
103 int temp; \
104 \
105 do { \
106 __asm__ __volatile__( \
107 " .set "MIPS_ISA_LEVEL" \n" \
108 " ll %1, %2 # atomic_" #op "_return \n" \
109 " " #asm_op " %0, %1, %3 \n" \
110 " sc %0, %2 \n" \
111 " .set mips0 \n" \
112 : "=&r" (result), "=&r" (temp), \
113 "+" GCC_OFF_SMALL_ASM() (v->counter) \
114 : "Ir" (i)); \
115 } while (unlikely(!result)); \
116 \
117 result = temp; result c_op i; \
118 } else { \
119 unsigned long flags; \
120 \
121 raw_local_irq_save(flags); \
122 result = v->counter; \
123 result c_op i; \
124 v->counter = result; \
125 raw_local_irq_restore(flags); \
126 } \
127 \
128 smp_llsc_mb(); \
129 \
130 return result; \
131}
132
133#define ATOMIC_OPS(op, c_op, asm_op) \
134 ATOMIC_OP(op, c_op, asm_op) \
135 ATOMIC_OP_RETURN(op, c_op, asm_op)
136
137ATOMIC_OPS(add, +=, addu)
138ATOMIC_OPS(sub, -=, subu)
139
140ATOMIC_OP(and, &=, and)
141ATOMIC_OP(or, |=, or)
142ATOMIC_OP(xor, ^=, xor)
143
144#undef ATOMIC_OPS
145#undef ATOMIC_OP_RETURN
146#undef ATOMIC_OP
147
148/*
149 * atomic_sub_if_positive - conditionally subtract integer from atomic variable
150 * @i: integer value to subtract
151 * @v: pointer of type atomic_t
152 *
153 * Atomically test @v and subtract @i if @v is greater or equal than @i.
154 * The function returns the old value of @v minus @i.
155 */
156static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
157{
158 int result;
159
160 smp_mb__before_llsc();
161
162 if (kernel_uses_llsc && R10000_LLSC_WAR) {
163 int temp;
164
165 __asm__ __volatile__(
166 " .set arch=r4000 \n"
167 "1: ll %1, %2 # atomic_sub_if_positive\n"
168 " subu %0, %1, %3 \n"
169 " bltz %0, 1f \n"
170 " sc %0, %2 \n"
171 " .set noreorder \n"
172 " beqzl %0, 1b \n"
173 " subu %0, %1, %3 \n"
174 " .set reorder \n"
175 "1: \n"
176 " .set mips0 \n"
177 : "=&r" (result), "=&r" (temp),
178 "+" GCC_OFF_SMALL_ASM() (v->counter)
179 : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter)
180 : "memory");
181 } else if (kernel_uses_llsc) {
182 int temp;
183
184 __asm__ __volatile__(
185 " .set "MIPS_ISA_LEVEL" \n"
186 "1: ll %1, %2 # atomic_sub_if_positive\n"
187 " subu %0, %1, %3 \n"
188 " bltz %0, 1f \n"
189 " sc %0, %2 \n"
190 " .set noreorder \n"
191 " beqz %0, 1b \n"
192 " subu %0, %1, %3 \n"
193 " .set reorder \n"
194 "1: \n"
195 " .set mips0 \n"
196 : "=&r" (result), "=&r" (temp),
197 "+" GCC_OFF_SMALL_ASM() (v->counter)
198 : "Ir" (i));
199 } else {
200 unsigned long flags;
201
202 raw_local_irq_save(flags);
203 result = v->counter;
204 result -= i;
205 if (result >= 0)
206 v->counter = result;
207 raw_local_irq_restore(flags);
208 }
209
210 smp_llsc_mb();
211
212 return result;
213}
214
215#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
216#define atomic_xchg(v, new) (xchg(&((v)->counter), (new)))
217
218/**
219 * __atomic_add_unless - add unless the number is a given value
220 * @v: pointer of type atomic_t
221 * @a: the amount to add to v...
222 * @u: ...unless v is equal to u.
223 *
224 * Atomically adds @a to @v, so long as it was not @u.
225 * Returns the old value of @v.
226 */
227static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
228{
229 int c, old;
230 c = atomic_read(v);
231 for (;;) {
232 if (unlikely(c == (u)))
233 break;
234 old = atomic_cmpxchg((v), c, c + (a));
235 if (likely(old == c))
236 break;
237 c = old;
238 }
239 return c;
240}
241
242#define atomic_dec_return(v) atomic_sub_return(1, (v))
243#define atomic_inc_return(v) atomic_add_return(1, (v))
244
245/*
246 * atomic_sub_and_test - subtract value from variable and test result
247 * @i: integer value to subtract
248 * @v: pointer of type atomic_t
249 *
250 * Atomically subtracts @i from @v and returns
251 * true if the result is zero, or false for all
252 * other cases.
253 */
254#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
255
256/*
257 * atomic_inc_and_test - increment and test
258 * @v: pointer of type atomic_t
259 *
260 * Atomically increments @v by 1
261 * and returns true if the result is zero, or false for all
262 * other cases.
263 */
264#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
265
266/*
267 * atomic_dec_and_test - decrement by 1 and test
268 * @v: pointer of type atomic_t
269 *
270 * Atomically decrements @v by 1 and
271 * returns true if the result is 0, or false for all other
272 * cases.
273 */
274#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
275
276/*
277 * atomic_dec_if_positive - decrement by 1 if old value positive
278 * @v: pointer of type atomic_t
279 */
280#define atomic_dec_if_positive(v) atomic_sub_if_positive(1, v)
281
282/*
283 * atomic_inc - increment atomic variable
284 * @v: pointer of type atomic_t
285 *
286 * Atomically increments @v by 1.
287 */
288#define atomic_inc(v) atomic_add(1, (v))
289
290/*
291 * atomic_dec - decrement and test
292 * @v: pointer of type atomic_t
293 *
294 * Atomically decrements @v by 1.
295 */
296#define atomic_dec(v) atomic_sub(1, (v))
297
298/*
299 * atomic_add_negative - add and test if negative
300 * @v: pointer of type atomic_t
301 * @i: integer value to add
302 *
303 * Atomically adds @i to @v and returns true
304 * if the result is negative, or false when
305 * result is greater than or equal to zero.
306 */
307#define atomic_add_negative(i, v) (atomic_add_return(i, (v)) < 0)
308
309#ifdef CONFIG_64BIT
310
311#define ATOMIC64_INIT(i) { (i) }
312
313/*
314 * atomic64_read - read atomic variable
315 * @v: pointer of type atomic64_t
316 *
317 */
318#define atomic64_read(v) READ_ONCE((v)->counter)
319
320/*
321 * atomic64_set - set atomic variable
322 * @v: pointer of type atomic64_t
323 * @i: required value
324 */
325#define atomic64_set(v, i) WRITE_ONCE((v)->counter, (i))
326
327#define ATOMIC64_OP(op, c_op, asm_op) \
328static __inline__ void atomic64_##op(long i, atomic64_t * v) \
329{ \
330 if (kernel_uses_llsc && R10000_LLSC_WAR) { \
331 long temp; \
332 \
333 __asm__ __volatile__( \
334 " .set arch=r4000 \n" \
335 "1: lld %0, %1 # atomic64_" #op " \n" \
336 " " #asm_op " %0, %2 \n" \
337 " scd %0, %1 \n" \
338 " beqzl %0, 1b \n" \
339 " .set mips0 \n" \
340 : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
341 : "Ir" (i)); \
342 } else if (kernel_uses_llsc) { \
343 long temp; \
344 \
345 do { \
346 __asm__ __volatile__( \
347 " .set "MIPS_ISA_LEVEL" \n" \
348 " lld %0, %1 # atomic64_" #op "\n" \
349 " " #asm_op " %0, %2 \n" \
350 " scd %0, %1 \n" \
351 " .set mips0 \n" \
352 : "=&r" (temp), "+" GCC_OFF_SMALL_ASM() (v->counter) \
353 : "Ir" (i)); \
354 } while (unlikely(!temp)); \
355 } else { \
356 unsigned long flags; \
357 \
358 raw_local_irq_save(flags); \
359 v->counter c_op i; \
360 raw_local_irq_restore(flags); \
361 } \
362}
363
364#define ATOMIC64_OP_RETURN(op, c_op, asm_op) \
365static __inline__ long atomic64_##op##_return(long i, atomic64_t * v) \
366{ \
367 long result; \
368 \
369 smp_mb__before_llsc(); \
370 \
371 if (kernel_uses_llsc && R10000_LLSC_WAR) { \
372 long temp; \
373 \
374 __asm__ __volatile__( \
375 " .set arch=r4000 \n" \
376 "1: lld %1, %2 # atomic64_" #op "_return\n" \
377 " " #asm_op " %0, %1, %3 \n" \
378 " scd %0, %2 \n" \
379 " beqzl %0, 1b \n" \
380 " " #asm_op " %0, %1, %3 \n" \
381 " .set mips0 \n" \
382 : "=&r" (result), "=&r" (temp), \
383 "+" GCC_OFF_SMALL_ASM() (v->counter) \
384 : "Ir" (i)); \
385 } else if (kernel_uses_llsc) { \
386 long temp; \
387 \
388 do { \
389 __asm__ __volatile__( \
390 " .set "MIPS_ISA_LEVEL" \n" \
391 " lld %1, %2 # atomic64_" #op "_return\n" \
392 " " #asm_op " %0, %1, %3 \n" \
393 " scd %0, %2 \n" \
394 " .set mips0 \n" \
395 : "=&r" (result), "=&r" (temp), \
396 "=" GCC_OFF_SMALL_ASM() (v->counter) \
397 : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter) \
398 : "memory"); \
399 } while (unlikely(!result)); \
400 \
401 result = temp; result c_op i; \
402 } else { \
403 unsigned long flags; \
404 \
405 raw_local_irq_save(flags); \
406 result = v->counter; \
407 result c_op i; \
408 v->counter = result; \
409 raw_local_irq_restore(flags); \
410 } \
411 \
412 smp_llsc_mb(); \
413 \
414 return result; \
415}
416
417#define ATOMIC64_OPS(op, c_op, asm_op) \
418 ATOMIC64_OP(op, c_op, asm_op) \
419 ATOMIC64_OP_RETURN(op, c_op, asm_op)
420
421ATOMIC64_OPS(add, +=, daddu)
422ATOMIC64_OPS(sub, -=, dsubu)
423ATOMIC64_OP(and, &=, and)
424ATOMIC64_OP(or, |=, or)
425ATOMIC64_OP(xor, ^=, xor)
426
427#undef ATOMIC64_OPS
428#undef ATOMIC64_OP_RETURN
429#undef ATOMIC64_OP
430
431/*
432 * atomic64_sub_if_positive - conditionally subtract integer from atomic
433 * variable
434 * @i: integer value to subtract
435 * @v: pointer of type atomic64_t
436 *
437 * Atomically test @v and subtract @i if @v is greater or equal than @i.
438 * The function returns the old value of @v minus @i.
439 */
440static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
441{
442 long result;
443
444 smp_mb__before_llsc();
445
446 if (kernel_uses_llsc && R10000_LLSC_WAR) {
447 long temp;
448
449 __asm__ __volatile__(
450 " .set arch=r4000 \n"
451 "1: lld %1, %2 # atomic64_sub_if_positive\n"
452 " dsubu %0, %1, %3 \n"
453 " bltz %0, 1f \n"
454 " scd %0, %2 \n"
455 " .set noreorder \n"
456 " beqzl %0, 1b \n"
457 " dsubu %0, %1, %3 \n"
458 " .set reorder \n"
459 "1: \n"
460 " .set mips0 \n"
461 : "=&r" (result), "=&r" (temp),
462 "=" GCC_OFF_SMALL_ASM() (v->counter)
463 : "Ir" (i), GCC_OFF_SMALL_ASM() (v->counter)
464 : "memory");
465 } else if (kernel_uses_llsc) {
466 long temp;
467
468 __asm__ __volatile__(
469 " .set "MIPS_ISA_LEVEL" \n"
470 "1: lld %1, %2 # atomic64_sub_if_positive\n"
471 " dsubu %0, %1, %3 \n"
472 " bltz %0, 1f \n"
473 " scd %0, %2 \n"
474 " .set noreorder \n"
475 " beqz %0, 1b \n"
476 " dsubu %0, %1, %3 \n"
477 " .set reorder \n"
478 "1: \n"
479 " .set mips0 \n"
480 : "=&r" (result), "=&r" (temp),
481 "+" GCC_OFF_SMALL_ASM() (v->counter)
482 : "Ir" (i));
483 } else {
484 unsigned long flags;
485
486 raw_local_irq_save(flags);
487 result = v->counter;
488 result -= i;
489 if (result >= 0)
490 v->counter = result;
491 raw_local_irq_restore(flags);
492 }
493
494 smp_llsc_mb();
495
496 return result;
497}
498
499#define atomic64_cmpxchg(v, o, n) \
500 ((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n)))
501#define atomic64_xchg(v, new) (xchg(&((v)->counter), (new)))
502
503/**
504 * atomic64_add_unless - add unless the number is a given value
505 * @v: pointer of type atomic64_t
506 * @a: the amount to add to v...
507 * @u: ...unless v is equal to u.
508 *
509 * Atomically adds @a to @v, so long as it was not @u.
510 * Returns true iff @v was not @u.
511 */
512static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
513{
514 long c, old;
515 c = atomic64_read(v);
516 for (;;) {
517 if (unlikely(c == (u)))
518 break;
519 old = atomic64_cmpxchg((v), c, c + (a));
520 if (likely(old == c))
521 break;
522 c = old;
523 }
524 return c != (u);
525}
526
527#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
528
529#define atomic64_dec_return(v) atomic64_sub_return(1, (v))
530#define atomic64_inc_return(v) atomic64_add_return(1, (v))
531
532/*
533 * atomic64_sub_and_test - subtract value from variable and test result
534 * @i: integer value to subtract
535 * @v: pointer of type atomic64_t
536 *
537 * Atomically subtracts @i from @v and returns
538 * true if the result is zero, or false for all
539 * other cases.
540 */
541#define atomic64_sub_and_test(i, v) (atomic64_sub_return((i), (v)) == 0)
542
543/*
544 * atomic64_inc_and_test - increment and test
545 * @v: pointer of type atomic64_t
546 *
547 * Atomically increments @v by 1
548 * and returns true if the result is zero, or false for all
549 * other cases.
550 */
551#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
552
553/*
554 * atomic64_dec_and_test - decrement by 1 and test
555 * @v: pointer of type atomic64_t
556 *
557 * Atomically decrements @v by 1 and
558 * returns true if the result is 0, or false for all other
559 * cases.
560 */
561#define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
562
563/*
564 * atomic64_dec_if_positive - decrement by 1 if old value positive
565 * @v: pointer of type atomic64_t
566 */
567#define atomic64_dec_if_positive(v) atomic64_sub_if_positive(1, v)
568
569/*
570 * atomic64_inc - increment atomic variable
571 * @v: pointer of type atomic64_t
572 *
573 * Atomically increments @v by 1.
574 */
575#define atomic64_inc(v) atomic64_add(1, (v))
576
577/*
578 * atomic64_dec - decrement and test
579 * @v: pointer of type atomic64_t
580 *
581 * Atomically decrements @v by 1.
582 */
583#define atomic64_dec(v) atomic64_sub(1, (v))
584
585/*
586 * atomic64_add_negative - add and test if negative
587 * @v: pointer of type atomic64_t
588 * @i: integer value to add
589 *
590 * Atomically adds @i to @v and returns true
591 * if the result is negative, or false when
592 * result is greater than or equal to zero.
593 */
594#define atomic64_add_negative(i, v) (atomic64_add_return(i, (v)) < 0)
595
596#endif /* CONFIG_64BIT */
597
598#endif /* _ASM_ATOMIC_H */