xref: /openbmc/linux/arch/sparc/lib/atomic_64.S (revision 9cfc5c90) 
1/* atomic.S: These things are too big to do inline.
2 *
3 * Copyright (C) 1999, 2007 2012 David S. Miller (davem@davemloft.net)
4 */
5
6#include <linux/linkage.h>
7#include <asm/asi.h>
8#include <asm/backoff.h>
9
10	.text
11
12	/* Two versions of the atomic routines, one that
13	 * does not return a value and does not perform
14	 * memory barriers, and a second which returns
15	 * a value and does the barriers.
16	 */
17
18#define ATOMIC_OP(op)							\
19ENTRY(atomic_##op) /* %o0 = increment, %o1 = atomic_ptr */		\
20	BACKOFF_SETUP(%o2);						\
211:	lduw	[%o1], %g1;						\
22	op	%g1, %o0, %g7;						\
23	cas	[%o1], %g1, %g7;					\
24	cmp	%g1, %g7;						\
25	bne,pn	%icc, BACKOFF_LABEL(2f, 1b);				\
26	 nop;								\
27	retl;								\
28	 nop;								\
292:	BACKOFF_SPIN(%o2, %o3, 1b);					\
30ENDPROC(atomic_##op);							\
31
32#define ATOMIC_OP_RETURN(op)						\
33ENTRY(atomic_##op##_return) /* %o0 = increment, %o1 = atomic_ptr */	\
34	BACKOFF_SETUP(%o2);						\
351:	lduw	[%o1], %g1;						\
36	op	%g1, %o0, %g7;						\
37	cas	[%o1], %g1, %g7;					\
38	cmp	%g1, %g7;						\
39	bne,pn	%icc, BACKOFF_LABEL(2f, 1b);				\
40	 op	%g1, %o0, %g1;						\
41	retl;								\
42	 sra	%g1, 0, %o0;						\
432:	BACKOFF_SPIN(%o2, %o3, 1b);					\
44ENDPROC(atomic_##op##_return);
45
46#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op)
47
48ATOMIC_OPS(add)
49ATOMIC_OPS(sub)
50ATOMIC_OP(and)
51ATOMIC_OP(or)
52ATOMIC_OP(xor)
53
54#undef ATOMIC_OPS
55#undef ATOMIC_OP_RETURN
56#undef ATOMIC_OP
57
58#define ATOMIC64_OP(op)							\
59ENTRY(atomic64_##op) /* %o0 = increment, %o1 = atomic_ptr */		\
60	BACKOFF_SETUP(%o2);						\
611:	ldx	[%o1], %g1;						\
62	op	%g1, %o0, %g7;						\
63	casx	[%o1], %g1, %g7;					\
64	cmp	%g1, %g7;						\
65	bne,pn	%xcc, BACKOFF_LABEL(2f, 1b);				\
66	 nop;								\
67	retl;								\
68	 nop;								\
692:	BACKOFF_SPIN(%o2, %o3, 1b);					\
70ENDPROC(atomic64_##op);							\
71
72#define ATOMIC64_OP_RETURN(op)						\
73ENTRY(atomic64_##op##_return) /* %o0 = increment, %o1 = atomic_ptr */	\
74	BACKOFF_SETUP(%o2);						\
751:	ldx	[%o1], %g1;						\
76	op	%g1, %o0, %g7;						\
77	casx	[%o1], %g1, %g7;					\
78	cmp	%g1, %g7;						\
79	bne,pn	%xcc, BACKOFF_LABEL(2f, 1b);				\
80	 nop;								\
81	retl;								\
82	 op	%g1, %o0, %o0;						\
832:	BACKOFF_SPIN(%o2, %o3, 1b);					\
84ENDPROC(atomic64_##op##_return);
85
86#define ATOMIC64_OPS(op) ATOMIC64_OP(op) ATOMIC64_OP_RETURN(op)
87
88ATOMIC64_OPS(add)
89ATOMIC64_OPS(sub)
90ATOMIC64_OP(and)
91ATOMIC64_OP(or)
92ATOMIC64_OP(xor)
93
94#undef ATOMIC64_OPS
95#undef ATOMIC64_OP_RETURN
96#undef ATOMIC64_OP
97
98ENTRY(atomic64_dec_if_positive) /* %o0 = atomic_ptr */
99	BACKOFF_SETUP(%o2)
1001:	ldx	[%o0], %g1
101	brlez,pn %g1, 3f
102	 sub	%g1, 1, %g7
103	casx	[%o0], %g1, %g7
104	cmp	%g1, %g7
105	bne,pn	%xcc, BACKOFF_LABEL(2f, 1b)
106	 nop
1073:	retl
108	 sub	%g1, 1, %o0
1092:	BACKOFF_SPIN(%o2, %o3, 1b)
110ENDPROC(atomic64_dec_if_positive)
111