1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ARCH_MIPS_LOCAL_H
3#define _ARCH_MIPS_LOCAL_H
4
5#include <linux/percpu.h>
6#include <linux/bitops.h>
7#include <linux/atomic.h>
8#include <asm/asm.h>
9#include <asm/cmpxchg.h>
10#include <asm/compiler.h>
11
12typedef struct
13{
14	atomic_long_t a;
15} local_t;
16
17#define LOCAL_INIT(i)	{ ATOMIC_LONG_INIT(i) }
18
19#define local_read(l)	atomic_long_read(&(l)->a)
20#define local_set(l, i) atomic_long_set(&(l)->a, (i))
21
22#define local_add(i, l) atomic_long_add((i), (&(l)->a))
23#define local_sub(i, l) atomic_long_sub((i), (&(l)->a))
24#define local_inc(l)	atomic_long_inc(&(l)->a)
25#define local_dec(l)	atomic_long_dec(&(l)->a)
26
27/*
28 * Same as above, but return the result value
29 */
30static __inline__ long local_add_return(long i, local_t * l)
31{
32	unsigned long result;
33
34	if (kernel_uses_llsc) {
35		unsigned long temp;
36
37		__asm__ __volatile__(
38		"	.set	push					\n"
39		"	.set	"MIPS_ISA_ARCH_LEVEL"			\n"
40			__SYNC(full, loongson3_war) "                   \n"
41		"1:"	__stringify(LONG_LL)	"	%1, %2		\n"
42			__stringify(LONG_ADDU)	"	%0, %1, %3	\n"
43			__stringify(LONG_SC)	"	%0, %2		\n"
44			__stringify(SC_BEQZ)	"	%0, 1b		\n"
45			__stringify(LONG_ADDU)	"	%0, %1, %3	\n"
46		"	.set	pop					\n"
47		: "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
48		: "Ir" (i), "m" (l->a.counter)
49		: "memory");
50	} else {
51		unsigned long flags;
52
53		local_irq_save(flags);
54		result = l->a.counter;
55		result += i;
56		l->a.counter = result;
57		local_irq_restore(flags);
58	}
59
60	return result;
61}
62
63static __inline__ long local_sub_return(long i, local_t * l)
64{
65	unsigned long result;
66
67	if (kernel_uses_llsc) {
68		unsigned long temp;
69
70		__asm__ __volatile__(
71		"	.set	push					\n"
72		"	.set	"MIPS_ISA_ARCH_LEVEL"			\n"
73			__SYNC(full, loongson3_war) "                   \n"
74		"1:"	__stringify(LONG_LL)	"	%1, %2		\n"
75			__stringify(LONG_SUBU)	"	%0, %1, %3	\n"
76			__stringify(LONG_SUBU)	"	%0, %1, %3	\n"
77			__stringify(LONG_SC)	"	%0, %2		\n"
78			__stringify(SC_BEQZ)	"	%0, 1b		\n"
79			__stringify(LONG_SUBU)	"	%0, %1, %3	\n"
80		"	.set	pop					\n"
81		: "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
82		: "Ir" (i), "m" (l->a.counter)
83		: "memory");
84	} else {
85		unsigned long flags;
86
87		local_irq_save(flags);
88		result = l->a.counter;
89		result -= i;
90		l->a.counter = result;
91		local_irq_restore(flags);
92	}
93
94	return result;
95}
96
97static __inline__ long local_cmpxchg(local_t *l, long old, long new)
98{
99	return cmpxchg_local(&l->a.counter, old, new);
100}
101
102static __inline__ bool local_try_cmpxchg(local_t *l, long *old, long new)
103{
104	return try_cmpxchg_local(&l->a.counter,
105				 (typeof(l->a.counter) *) old, new);
106}
107
108#define local_xchg(l, n) (atomic_long_xchg((&(l)->a), (n)))
109
110/**
111 * local_add_unless - add unless the number is already a given value
112 * @l: pointer of type local_t
113 * @a: the amount to add to l...
114 * @u: ...unless l is equal to u.
115 *
116 * Atomically adds @a to @l, if @v was not already @u.
117 * Returns true if the addition was done.
118 */
119static __inline__ bool
120local_add_unless(local_t *l, long a, long u)
121{
122	long c = local_read(l);
123
124	do {
125		if (unlikely(c == u))
126			return false;
127	} while (!local_try_cmpxchg(l, &c, c + a));
128
129	return true;
130}
131
132#define local_inc_not_zero(l) local_add_unless((l), 1, 0)
133
134#define local_dec_return(l) local_sub_return(1, (l))
135#define local_inc_return(l) local_add_return(1, (l))
136
137/*
138 * local_sub_and_test - subtract value from variable and test result
139 * @i: integer value to subtract
140 * @l: pointer of type local_t
141 *
142 * Atomically subtracts @i from @l and returns
143 * true if the result is zero, or false for all
144 * other cases.
145 */
146#define local_sub_and_test(i, l) (local_sub_return((i), (l)) == 0)
147
148/*
149 * local_inc_and_test - increment and test
150 * @l: pointer of type local_t
151 *
152 * Atomically increments @l by 1
153 * and returns true if the result is zero, or false for all
154 * other cases.
155 */
156#define local_inc_and_test(l) (local_inc_return(l) == 0)
157
158/*
159 * local_dec_and_test - decrement by 1 and test
160 * @l: pointer of type local_t
161 *
162 * Atomically decrements @l by 1 and
163 * returns true if the result is 0, or false for all other
164 * cases.
165 */
166#define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)
167
168/*
169 * local_add_negative - add and test if negative
170 * @l: pointer of type local_t
171 * @i: integer value to add
172 *
173 * Atomically adds @i to @l and returns true
174 * if the result is negative, or false when
175 * result is greater than or equal to zero.
176 */
177#define local_add_negative(i, l) (local_add_return(i, (l)) < 0)
178
179/* Use these for per-cpu local_t variables: on some archs they are
180 * much more efficient than these naive implementations.  Note they take
181 * a variable, not an address.
182 */
183
184#define __local_inc(l)		((l)->a.counter++)
185#define __local_dec(l)		((l)->a.counter++)
186#define __local_add(i, l)	((l)->a.counter+=(i))
187#define __local_sub(i, l)	((l)->a.counter-=(i))
188
189#endif /* _ARCH_MIPS_LOCAL_H */
190