xref: /openbmc/linux/arch/mips/include/asm/local.h (revision 9a29f5fc)
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 
12 typedef 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  */
30 static __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 
63 static __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 
97 #define local_cmpxchg(l, o, n) \
98 	((long)cmpxchg_local(&((l)->a.counter), (o), (n)))
99 #define local_xchg(l, n) (atomic_long_xchg((&(l)->a), (n)))
100 
101 /**
102  * local_add_unless - add unless the number is a given value
103  * @l: pointer of type local_t
104  * @a: the amount to add to l...
105  * @u: ...unless l is equal to u.
106  *
107  * Atomically adds @a to @l, so long as it was not @u.
108  * Returns non-zero if @l was not @u, and zero otherwise.
109  */
110 #define local_add_unless(l, a, u)				\
111 ({								\
112 	long c, old;						\
113 	c = local_read(l);					\
114 	while (c != (u) && (old = local_cmpxchg((l), c, c + (a))) != c) \
115 		c = old;					\
116 	c != (u);						\
117 })
118 #define local_inc_not_zero(l) local_add_unless((l), 1, 0)
119 
120 #define local_dec_return(l) local_sub_return(1, (l))
121 #define local_inc_return(l) local_add_return(1, (l))
122 
123 /*
124  * local_sub_and_test - subtract value from variable and test result
125  * @i: integer value to subtract
126  * @l: pointer of type local_t
127  *
128  * Atomically subtracts @i from @l and returns
129  * true if the result is zero, or false for all
130  * other cases.
131  */
132 #define local_sub_and_test(i, l) (local_sub_return((i), (l)) == 0)
133 
134 /*
135  * local_inc_and_test - increment and test
136  * @l: pointer of type local_t
137  *
138  * Atomically increments @l by 1
139  * and returns true if the result is zero, or false for all
140  * other cases.
141  */
142 #define local_inc_and_test(l) (local_inc_return(l) == 0)
143 
144 /*
145  * local_dec_and_test - decrement by 1 and test
146  * @l: pointer of type local_t
147  *
148  * Atomically decrements @l by 1 and
149  * returns true if the result is 0, or false for all other
150  * cases.
151  */
152 #define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)
153 
154 /*
155  * local_add_negative - add and test if negative
156  * @l: pointer of type local_t
157  * @i: integer value to add
158  *
159  * Atomically adds @i to @l and returns true
160  * if the result is negative, or false when
161  * result is greater than or equal to zero.
162  */
163 #define local_add_negative(i, l) (local_add_return(i, (l)) < 0)
164 
165 /* Use these for per-cpu local_t variables: on some archs they are
166  * much more efficient than these naive implementations.  Note they take
167  * a variable, not an address.
168  */
169 
170 #define __local_inc(l)		((l)->a.counter++)
171 #define __local_dec(l)		((l)->a.counter++)
172 #define __local_add(i, l)	((l)->a.counter+=(i))
173 #define __local_sub(i, l)	((l)->a.counter-=(i))
174 
175 #endif /* _ARCH_MIPS_LOCAL_H */
176