xref: /openbmc/linux/arch/sparc/lib/memscan_64.S (revision 4cdb71b6)
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * memscan.S: Optimized memscan for Sparc64.
4 *
5 * Copyright (C) 1997,1998 Jakub Jelinek (jj@ultra.linux.cz)
6 * Copyright (C) 1998 David S. Miller (davem@redhat.com)
7 */
8
9#include <linux/export.h>
10
11#define HI_MAGIC	0x8080808080808080
12#define LO_MAGIC	0x0101010101010101
13#define ASI_PL		0x88
14
15	.text
16	.align	32
17	.globl		__memscan_zero, __memscan_generic
18	.type		__memscan_zero,#function
19	.type		__memscan_generic,#function
20	.globl		memscan
21	EXPORT_SYMBOL(__memscan_zero)
22	EXPORT_SYMBOL(__memscan_generic)
23
24__memscan_zero:
25	/* %o0 = bufp, %o1 = size */
26	brlez,pn	%o1, szzero
27	 andcc		%o0, 7, %g0
28	be,pt		%icc, we_are_aligned
29	 sethi		%hi(HI_MAGIC), %o4
30	ldub		[%o0], %o5
311:	subcc		%o1, 1, %o1
32	brz,pn		%o5, 10f
33	 add		%o0, 1, %o0
34
35	be,pn		%xcc, szzero
36	 andcc		%o0, 7, %g0
37	bne,a,pn	%icc, 1b
38	 ldub		[%o0], %o5
39we_are_aligned:
40	ldxa		[%o0] ASI_PL, %o5
41	or		%o4, %lo(HI_MAGIC), %o3
42	sllx		%o3, 32, %o4
43	or		%o4, %o3, %o3
44
45	srlx		%o3, 7, %o2
46msloop:
47	sub		%o1, 8, %o1
48	add		%o0, 8, %o0
49	sub		%o5, %o2, %o4
50	xor		%o4, %o5, %o4
51	andcc		%o4, %o3, %g3
52	bne,pn		%xcc, check_bytes
53	 srlx		%o4, 32, %g3
54
55	brgz,a,pt	%o1, msloop
56	 ldxa		[%o0] ASI_PL, %o5
57check_bytes:
58	bne,a,pn	%icc, 2f
59	 andcc		%o5, 0xff, %g0
60	add		%o0, -5, %g2
61	ba,pt		%xcc, 3f
62	 srlx		%o5, 32, %g7
63
642:	srlx		%o5, 8, %g7
65	be,pn		%icc, 1f
66	 add		%o0, -8, %g2
67	andcc		%g7, 0xff, %g0
68	srlx		%g7, 8, %g7
69	be,pn		%icc, 1f
70	 inc		%g2
71	andcc		%g7, 0xff, %g0
72
73	srlx		%g7, 8, %g7
74	be,pn		%icc, 1f
75	 inc		%g2
76	andcc		%g7, 0xff, %g0
77	srlx		%g7, 8, %g7
78	be,pn		%icc, 1f
79	 inc		%g2
80	andcc		%g3, %o3, %g0
81
82	be,a,pn		%icc, 2f
83	 mov		%o0, %g2
843:	andcc		%g7, 0xff, %g0
85	srlx		%g7, 8, %g7
86	be,pn		%icc, 1f
87	 inc		%g2
88	andcc		%g7, 0xff, %g0
89	srlx		%g7, 8, %g7
90
91	be,pn		%icc, 1f
92	 inc		%g2
93	andcc		%g7, 0xff, %g0
94	srlx		%g7, 8, %g7
95	be,pn		%icc, 1f
96	 inc		%g2
97	andcc		%g7, 0xff, %g0
98	srlx		%g7, 8, %g7
99
100	be,pn		%icc, 1f
101	 inc		%g2
1022:	brgz,a,pt	%o1, msloop
103	 ldxa		[%o0] ASI_PL, %o5
104	inc		%g2
1051:	add		%o0, %o1, %o0
106	cmp		%g2, %o0
107	retl
108
109	 movle		%xcc, %g2, %o0
11010:	retl
111	 sub		%o0, 1, %o0
112szzero:	retl
113	 nop
114
115memscan:
116__memscan_generic:
117	/* %o0 = addr, %o1 = c, %o2 = size */
118	brz,pn		%o2, 3f
119	 add		%o0, %o2, %o3
120	ldub		[%o0], %o5
121	sub		%g0, %o2, %o4
1221:
123	cmp		%o5, %o1
124	be,pn		%icc, 2f
125	 addcc		%o4, 1, %o4
126	bne,a,pt 	%xcc, 1b
127	 ldub		[%o3 + %o4], %o5
128	retl
129	/* The delay slot is the same as the next insn, this is just to make it look more awful */
1302:
131	 add		%o3, %o4, %o0
132	retl
133	 sub		%o0, 1, %o0
1343:
135	retl
136	 nop
137