xref: /openbmc/linux/arch/mips/include/asm/local.h (revision dc6a81c3)
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/cmpxchg.h>
9 #include <asm/compiler.h>
10 #include <asm/war.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 && R10000_LLSC_WAR) {
35 		unsigned long temp;
36 
37 		__asm__ __volatile__(
38 		"	.set	push					\n"
39 		"	.set	arch=r4000				\n"
40 			__SYNC(full, loongson3_war) "			\n"
41 		"1:"	__LL	"%1, %2		# local_add_return	\n"
42 		"	addu	%0, %1, %3				\n"
43 			__SC	"%0, %2					\n"
44 		"	beqzl	%0, 1b					\n"
45 		"	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 if (kernel_uses_llsc) {
51 		unsigned long temp;
52 
53 		__asm__ __volatile__(
54 		"	.set	push					\n"
55 		"	.set	"MIPS_ISA_ARCH_LEVEL"			\n"
56 			__SYNC(full, loongson3_war) "			\n"
57 		"1:"	__LL	"%1, %2		# local_add_return	\n"
58 		"	addu	%0, %1, %3				\n"
59 			__SC	"%0, %2					\n"
60 		"	beqz	%0, 1b					\n"
61 		"	addu	%0, %1, %3				\n"
62 		"	.set	pop					\n"
63 		: "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
64 		: "Ir" (i), "m" (l->a.counter)
65 		: "memory");
66 	} else {
67 		unsigned long flags;
68 
69 		local_irq_save(flags);
70 		result = l->a.counter;
71 		result += i;
72 		l->a.counter = result;
73 		local_irq_restore(flags);
74 	}
75 
76 	return result;
77 }
78 
79 static __inline__ long local_sub_return(long i, local_t * l)
80 {
81 	unsigned long result;
82 
83 	if (kernel_uses_llsc && R10000_LLSC_WAR) {
84 		unsigned long temp;
85 
86 		__asm__ __volatile__(
87 		"	.set	push					\n"
88 		"	.set	arch=r4000				\n"
89 			__SYNC(full, loongson3_war) "			\n"
90 		"1:"	__LL	"%1, %2		# local_sub_return	\n"
91 		"	subu	%0, %1, %3				\n"
92 			__SC	"%0, %2					\n"
93 		"	beqzl	%0, 1b					\n"
94 		"	subu	%0, %1, %3				\n"
95 		"	.set	pop					\n"
96 		: "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
97 		: "Ir" (i), "m" (l->a.counter)
98 		: "memory");
99 	} else if (kernel_uses_llsc) {
100 		unsigned long temp;
101 
102 		__asm__ __volatile__(
103 		"	.set	push					\n"
104 		"	.set	"MIPS_ISA_ARCH_LEVEL"			\n"
105 			__SYNC(full, loongson3_war) "			\n"
106 		"1:"	__LL	"%1, %2		# local_sub_return	\n"
107 		"	subu	%0, %1, %3				\n"
108 			__SC	"%0, %2					\n"
109 		"	beqz	%0, 1b					\n"
110 		"	subu	%0, %1, %3				\n"
111 		"	.set	pop					\n"
112 		: "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
113 		: "Ir" (i), "m" (l->a.counter)
114 		: "memory");
115 	} else {
116 		unsigned long flags;
117 
118 		local_irq_save(flags);
119 		result = l->a.counter;
120 		result -= i;
121 		l->a.counter = result;
122 		local_irq_restore(flags);
123 	}
124 
125 	return result;
126 }
127 
128 #define local_cmpxchg(l, o, n) \
129 	((long)cmpxchg_local(&((l)->a.counter), (o), (n)))
130 #define local_xchg(l, n) (atomic_long_xchg((&(l)->a), (n)))
131 
132 /**
133  * local_add_unless - add unless the number is a given value
134  * @l: pointer of type local_t
135  * @a: the amount to add to l...
136  * @u: ...unless l is equal to u.
137  *
138  * Atomically adds @a to @l, so long as it was not @u.
139  * Returns non-zero if @l was not @u, and zero otherwise.
140  */
141 #define local_add_unless(l, a, u)				\
142 ({								\
143 	long c, old;						\
144 	c = local_read(l);					\
145 	while (c != (u) && (old = local_cmpxchg((l), c, c + (a))) != c) \
146 		c = old;					\
147 	c != (u);						\
148 })
149 #define local_inc_not_zero(l) local_add_unless((l), 1, 0)
150 
151 #define local_dec_return(l) local_sub_return(1, (l))
152 #define local_inc_return(l) local_add_return(1, (l))
153 
154 /*
155  * local_sub_and_test - subtract value from variable and test result
156  * @i: integer value to subtract
157  * @l: pointer of type local_t
158  *
159  * Atomically subtracts @i from @l and returns
160  * true if the result is zero, or false for all
161  * other cases.
162  */
163 #define local_sub_and_test(i, l) (local_sub_return((i), (l)) == 0)
164 
165 /*
166  * local_inc_and_test - increment and test
167  * @l: pointer of type local_t
168  *
169  * Atomically increments @l by 1
170  * and returns true if the result is zero, or false for all
171  * other cases.
172  */
173 #define local_inc_and_test(l) (local_inc_return(l) == 0)
174 
175 /*
176  * local_dec_and_test - decrement by 1 and test
177  * @l: pointer of type local_t
178  *
179  * Atomically decrements @l by 1 and
180  * returns true if the result is 0, or false for all other
181  * cases.
182  */
183 #define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)
184 
185 /*
186  * local_add_negative - add and test if negative
187  * @l: pointer of type local_t
188  * @i: integer value to add
189  *
190  * Atomically adds @i to @l and returns true
191  * if the result is negative, or false when
192  * result is greater than or equal to zero.
193  */
194 #define local_add_negative(i, l) (local_add_return(i, (l)) < 0)
195 
196 /* Use these for per-cpu local_t variables: on some archs they are
197  * much more efficient than these naive implementations.  Note they take
198  * a variable, not an address.
199  */
200 
201 #define __local_inc(l)		((l)->a.counter++)
202 #define __local_dec(l)		((l)->a.counter++)
203 #define __local_add(i, l)	((l)->a.counter+=(i))
204 #define __local_sub(i, l)	((l)->a.counter-=(i))
205 
206 #endif /* _ARCH_MIPS_LOCAL_H */
207