1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Based on arch/arm/kernel/io.c
4 *
5 * Copyright (C) 2012 ARM Ltd.
6 */
7
8#include <linux/export.h>
9#include <linux/types.h>
10#include <linux/io.h>
11
12/*
13 * This generates a memcpy that works on a from/to address which is aligned to
14 * bits. Count is in terms of the number of bits sized quantities to copy. It
15 * optimizes to use the STR groupings when possible so that it is WC friendly.
16 */
17#define memcpy_toio_aligned(to, from, count, bits) \
18 ({ \
19 volatile u##bits __iomem *_to = to; \
20 const u##bits *_from = from; \
21 size_t _count = count; \
22 const u##bits *_end_from = _from + ALIGN_DOWN(_count, 8); \
23 \
24 for (; _from < _end_from; _from += 8, _to += 8) \
25 __const_memcpy_toio_aligned##bits(_to, _from, 8); \
26 if ((_count % 8) >= 4) { \
27 __const_memcpy_toio_aligned##bits(_to, _from, 4); \
28 _from += 4; \
29 _to += 4; \
30 } \
31 if ((_count % 4) >= 2) { \
32 __const_memcpy_toio_aligned##bits(_to, _from, 2); \
33 _from += 2; \
34 _to += 2; \
35 } \
36 if (_count % 2) \
37 __const_memcpy_toio_aligned##bits(_to, _from, 1); \
38 })
39
40void __iowrite64_copy_full(void __iomem *to, const void *from, size_t count)
41{
42 memcpy_toio_aligned(to, from, count, 64);
43 dgh();
44}
45EXPORT_SYMBOL(__iowrite64_copy_full);
46
47void __iowrite32_copy_full(void __iomem *to, const void *from, size_t count)
48{
49 memcpy_toio_aligned(to, from, count, 32);
50 dgh();
51}
52EXPORT_SYMBOL(__iowrite32_copy_full);
53

source code of linux/arch/arm64/kernel/io.c