xref: /openbmc/linux/arch/mips/include/asm/local.h (revision e190bfe5)
1 #ifndef _ARCH_MIPS_LOCAL_H
2 #define _ARCH_MIPS_LOCAL_H
3 
4 #include <linux/percpu.h>
5 #include <linux/bitops.h>
6 #include <asm/atomic.h>
7 #include <asm/cmpxchg.h>
8 #include <asm/war.h>
9 
10 typedef struct
11 {
12 	atomic_long_t a;
13 } local_t;
14 
15 #define LOCAL_INIT(i)	{ ATOMIC_LONG_INIT(i) }
16 
17 #define local_read(l)	atomic_long_read(&(l)->a)
18 #define local_set(l, i)	atomic_long_set(&(l)->a, (i))
19 
20 #define local_add(i, l)	atomic_long_add((i), (&(l)->a))
21 #define local_sub(i, l)	atomic_long_sub((i), (&(l)->a))
22 #define local_inc(l)	atomic_long_inc(&(l)->a)
23 #define local_dec(l)	atomic_long_dec(&(l)->a)
24 
25 /*
26  * Same as above, but return the result value
27  */
28 static __inline__ long local_add_return(long i, local_t * l)
29 {
30 	unsigned long result;
31 
32 	if (kernel_uses_llsc && R10000_LLSC_WAR) {
33 		unsigned long temp;
34 
35 		__asm__ __volatile__(
36 		"	.set	mips3					\n"
37 		"1:"	__LL	"%1, %2		# local_add_return	\n"
38 		"	addu	%0, %1, %3				\n"
39 			__SC	"%0, %2					\n"
40 		"	beqzl	%0, 1b					\n"
41 		"	addu	%0, %1, %3				\n"
42 		"	.set	mips0					\n"
43 		: "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
44 		: "Ir" (i), "m" (l->a.counter)
45 		: "memory");
46 	} else if (kernel_uses_llsc) {
47 		unsigned long temp;
48 
49 		__asm__ __volatile__(
50 		"	.set	mips3					\n"
51 		"1:"	__LL	"%1, %2		# local_add_return	\n"
52 		"	addu	%0, %1, %3				\n"
53 			__SC	"%0, %2					\n"
54 		"	beqz	%0, 1b					\n"
55 		"	addu	%0, %1, %3				\n"
56 		"	.set	mips0					\n"
57 		: "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
58 		: "Ir" (i), "m" (l->a.counter)
59 		: "memory");
60 	} else {
61 		unsigned long flags;
62 
63 		local_irq_save(flags);
64 		result = l->a.counter;
65 		result += i;
66 		l->a.counter = result;
67 		local_irq_restore(flags);
68 	}
69 
70 	return result;
71 }
72 
73 static __inline__ long local_sub_return(long i, local_t * l)
74 {
75 	unsigned long result;
76 
77 	if (kernel_uses_llsc && R10000_LLSC_WAR) {
78 		unsigned long temp;
79 
80 		__asm__ __volatile__(
81 		"	.set	mips3					\n"
82 		"1:"	__LL	"%1, %2		# local_sub_return	\n"
83 		"	subu	%0, %1, %3				\n"
84 			__SC	"%0, %2					\n"
85 		"	beqzl	%0, 1b					\n"
86 		"	subu	%0, %1, %3				\n"
87 		"	.set	mips0					\n"
88 		: "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
89 		: "Ir" (i), "m" (l->a.counter)
90 		: "memory");
91 	} else if (kernel_uses_llsc) {
92 		unsigned long temp;
93 
94 		__asm__ __volatile__(
95 		"	.set	mips3					\n"
96 		"1:"	__LL	"%1, %2		# local_sub_return	\n"
97 		"	subu	%0, %1, %3				\n"
98 			__SC	"%0, %2					\n"
99 		"	beqz	%0, 1b					\n"
100 		"	subu	%0, %1, %3				\n"
101 		"	.set	mips0					\n"
102 		: "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
103 		: "Ir" (i), "m" (l->a.counter)
104 		: "memory");
105 	} else {
106 		unsigned long flags;
107 
108 		local_irq_save(flags);
109 		result = l->a.counter;
110 		result -= i;
111 		l->a.counter = result;
112 		local_irq_restore(flags);
113 	}
114 
115 	return result;
116 }
117 
118 #define local_cmpxchg(l, o, n) \
119 	((long)cmpxchg_local(&((l)->a.counter), (o), (n)))
120 #define local_xchg(l, n) (xchg_local(&((l)->a.counter), (n)))
121 
122 /**
123  * local_add_unless - add unless the number is a given value
124  * @l: pointer of type local_t
125  * @a: the amount to add to l...
126  * @u: ...unless l is equal to u.
127  *
128  * Atomically adds @a to @l, so long as it was not @u.
129  * Returns non-zero if @l was not @u, and zero otherwise.
130  */
131 #define local_add_unless(l, a, u)				\
132 ({								\
133 	long c, old;						\
134 	c = local_read(l);					\
135 	while (c != (u) && (old = local_cmpxchg((l), c, c + (a))) != c) \
136 		c = old;					\
137 	c != (u);						\
138 })
139 #define local_inc_not_zero(l) local_add_unless((l), 1, 0)
140 
141 #define local_dec_return(l) local_sub_return(1, (l))
142 #define local_inc_return(l) local_add_return(1, (l))
143 
144 /*
145  * local_sub_and_test - subtract value from variable and test result
146  * @i: integer value to subtract
147  * @l: pointer of type local_t
148  *
149  * Atomically subtracts @i from @l and returns
150  * true if the result is zero, or false for all
151  * other cases.
152  */
153 #define local_sub_and_test(i, l) (local_sub_return((i), (l)) == 0)
154 
155 /*
156  * local_inc_and_test - increment and test
157  * @l: pointer of type local_t
158  *
159  * Atomically increments @l by 1
160  * and returns true if the result is zero, or false for all
161  * other cases.
162  */
163 #define local_inc_and_test(l) (local_inc_return(l) == 0)
164 
165 /*
166  * local_dec_and_test - decrement by 1 and test
167  * @l: pointer of type local_t
168  *
169  * Atomically decrements @l by 1 and
170  * returns true if the result is 0, or false for all other
171  * cases.
172  */
173 #define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)
174 
175 /*
176  * local_add_negative - add and test if negative
177  * @l: pointer of type local_t
178  * @i: integer value to add
179  *
180  * Atomically adds @i to @l and returns true
181  * if the result is negative, or false when
182  * result is greater than or equal to zero.
183  */
184 #define local_add_negative(i, l) (local_add_return(i, (l)) < 0)
185 
186 /* Use these for per-cpu local_t variables: on some archs they are
187  * much more efficient than these naive implementations.  Note they take
188  * a variable, not an address.
189  */
190 
191 #define __local_inc(l)		((l)->a.counter++)
192 #define __local_dec(l)		((l)->a.counter++)
193 #define __local_add(i, l)	((l)->a.counter+=(i))
194 #define __local_sub(i, l)	((l)->a.counter-=(i))
195 
196 #endif /* _ARCH_MIPS_LOCAL_H */
197