summaryrefslogtreecommitdiffstats
path: root/arch/arm64/kernel/io.c
blob: ef48089fbfe1a4694fe6083c596a5342a098c464 (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Based on arch/arm/kernel/io.c
 *
 * Copyright (C) 2012 ARM Ltd.
 */

#include <linux/export.h>
#include <linux/types.h>
#include <linux/io.h>

/*
 * Copy data from IO memory space to "real" memory space.
 */
void __memcpy_fromio(void *to, const volatile void __iomem *from, size_t count)
{
	while (count && !IS_ALIGNED((unsigned long)from, 8)) {
		*(u8 *)to = __raw_readb(from);
		from++;
		to++;
		count--;
	}

	while (count >= 8) {
		*(u64 *)to = __raw_readq(from);
		from += 8;
		to += 8;
		count -= 8;
	}

	while (count) {
		*(u8 *)to = __raw_readb(from);
		from++;
		to++;
		count--;
	}
}
EXPORT_SYMBOL(__memcpy_fromio);

/*
 * This generates a memcpy that works on a from/to address which is aligned to
 * bits. Count is in terms of the number of bits sized quantities to copy. It
 * optimizes to use the STR groupings when possible so that it is WC friendly.
 */
#define memcpy_toio_aligned(to, from, count, bits)                        \
	({                                                                \
		volatile u##bits __iomem *_to = to;                       \
		const u##bits *_from = from;                              \
		size_t _count = count;                                    \
		const u##bits *_end_from = _from + ALIGN_DOWN(_count, 8); \
                                                                          \
		for (; _from < _end_from; _from += 8, _to += 8)           \
			__const_memcpy_toio_aligned##bits(_to, _from, 8); \
		if ((_count % 8) >= 4) {                                  \
			__const_memcpy_toio_aligned##bits(_to, _from, 4); \
			_from += 4;                                       \
			_to += 4;                                         \
		}                                                         \
		if ((_count % 4) >= 2) {                                  \
			__const_memcpy_toio_aligned##bits(_to, _from, 2); \
			_from += 2;                                       \
			_to += 2;                                         \
		}                                                         \
		if (_count % 2)                                           \
			__const_memcpy_toio_aligned##bits(_to, _from, 1); \
	})

void __iowrite64_copy_full(void __iomem *to, const void *from, size_t count)
{
	memcpy_toio_aligned(to, from, count, 64);
	dgh();
}
EXPORT_SYMBOL(__iowrite64_copy_full);

void __iowrite32_copy_full(void __iomem *to, const void *from, size_t count)
{
	memcpy_toio_aligned(to, from, count, 32);
	dgh();
}
EXPORT_SYMBOL(__iowrite32_copy_full);

/*
 * Copy data from "real" memory space to IO memory space.
 */
void __memcpy_toio(volatile void __iomem *to, const void *from, size_t count)
{
	while (count && !IS_ALIGNED((unsigned long)to, 8)) {
		__raw_writeb(*(u8 *)from, to);
		from++;
		to++;
		count--;
	}

	while (count >= 8) {
		__raw_writeq(*(u64 *)from, to);
		from += 8;
		to += 8;
		count -= 8;
	}

	while (count) {
		__raw_writeb(*(u8 *)from, to);
		from++;
		to++;
		count--;
	}
}
EXPORT_SYMBOL(__memcpy_toio);

/*
 * "memset" on IO memory space.
 */
void __memset_io(volatile void __iomem *dst, int c, size_t count)
{
	u64 qc = (u8)c;

	qc |= qc << 8;
	qc |= qc << 16;
	qc |= qc << 32;

	while (count && !IS_ALIGNED((unsigned long)dst, 8)) {
		__raw_writeb(c, dst);
		dst++;
		count--;
	}

	while (count >= 8) {
		__raw_writeq(qc, dst);
		dst += 8;
		count -= 8;
	}

	while (count) {
		__raw_writeb(c, dst);
		dst++;
		count--;
	}
}
EXPORT_SYMBOL(__memset_io);