summaryrefslogtreecommitdiffstats
path: root/arch/arc/lib/memset-archs.S
blob: b3373f5c88e0bf9267af0cb9dbc7f5b0f6cf6be8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
/*
 * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/linkage.h>
#include <asm/cache.h>

/*
 * The memset implementation below is optimized to use prefetchw and prealloc
 * instruction in case of CPU with 64B L1 data cache line (L1_CACHE_SHIFT == 6)
 * If you want to implement optimized memset for other possible L1 data cache
 * line lengths (32B and 128B) you should rewrite code carefully checking
 * we don't call any prefetchw/prealloc instruction for L1 cache lines which
 * don't belongs to memset area.
 */

#if L1_CACHE_SHIFT == 6

.macro PREALLOC_INSTR	reg, off
	prealloc	[\reg, \off]
.endm

.macro PREFETCHW_INSTR	reg, off
	prefetchw	[\reg, \off]
.endm

#else

.macro PREALLOC_INSTR	reg, off
.endm

.macro PREFETCHW_INSTR	reg, off
.endm

#endif

ENTRY_CFI(memset)
	PREFETCHW_INSTR	r0, 0	; Prefetch the first write location
	mov.f	0, r2
;;; if size is zero
	jz.d	[blink]
	mov	r3, r0		; don't clobber ret val

;;; if length < 8
	brls.d.nt	r2, 8, .Lsmallchunk
	mov.f	lp_count,r2

	and.f	r4, r0, 0x03
	rsub	lp_count, r4, 4
	lpnz	@.Laligndestination
	;; LOOP BEGIN
	stb.ab	r1, [r3,1]
	sub	r2, r2, 1
.Laligndestination:

;;; Destination is aligned
	and	r1, r1, 0xFF
	asl	r4, r1, 8
	or	r4, r4, r1
	asl	r5, r4, 16
	or	r5, r5, r4
	mov	r4, r5

	sub3	lp_count, r2, 8
	cmp     r2, 64
	bmsk.hi	r2, r2, 5
	mov.ls	lp_count, 0
	add3.hi	r2, r2, 8

;;; Convert len to Dwords, unfold x8
	lsr.f	lp_count, lp_count, 6

	lpnz	@.Lset64bytes
	;; LOOP START
	PREALLOC_INSTR	r3, 64	; alloc next line w/o fetching

#ifdef CONFIG_ARC_HAS_LL64
	std.ab	r4, [r3, 8]
	std.ab	r4, [r3, 8]
	std.ab	r4, [r3, 8]
	std.ab	r4, [r3, 8]
	std.ab	r4, [r3, 8]
	std.ab	r4, [r3, 8]
	std.ab	r4, [r3, 8]
	std.ab	r4, [r3, 8]
#else
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
#endif
.Lset64bytes:

	lsr.f	lp_count, r2, 5 ;Last remaining  max 124 bytes
	lpnz	.Lset32bytes
	;; LOOP START
#ifdef CONFIG_ARC_HAS_LL64
	std.ab	r4, [r3, 8]
	std.ab	r4, [r3, 8]
	std.ab	r4, [r3, 8]
	std.ab	r4, [r3, 8]
#else
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
	st.ab	r4, [r3, 4]
#endif
.Lset32bytes:

	and.f	lp_count, r2, 0x1F ;Last remaining 31 bytes
.Lsmallchunk:
	lpnz	.Lcopy3bytes
	;; LOOP START
	stb.ab	r1, [r3, 1]
.Lcopy3bytes:

	j	[blink]

END_CFI(memset)

ENTRY_CFI(memzero)
    ; adjust bzero args to memset args
    mov r2, r1
    b.d  memset    ;tail call so need to tinker with blink
    mov r1, 0
END_CFI(memzero)