io.c

 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);