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 * Copy data from IO memory space to "real" memory space.
14 */
__memcpy_fromio(void * to,const volatile void __iomem * from,size_t count)15 void __memcpy_fromio(void *to, const volatile void __iomem *from, size_t count)
16 {
17 while (count && !IS_ALIGNED((unsigned long)from, 8)) {
18 *(u8 *)to = __raw_readb(from);
19 from++;
20 to++;
21 count--;
22 }
23
24 while (count >= 8) {
25 *(u64 *)to = __raw_readq(from);
26 from += 8;
27 to += 8;
28 count -= 8;
29 }
30
31 while (count) {
32 *(u8 *)to = __raw_readb(from);
33 from++;
34 to++;
35 count--;
36 }
37 }
38 EXPORT_SYMBOL(__memcpy_fromio);
39
40 /*
41 * Copy data from "real" memory space to IO memory space.
42 */
__memcpy_toio(volatile void __iomem * to,const void * from,size_t count)43 void __memcpy_toio(volatile void __iomem *to, const void *from, size_t count)
44 {
45 while (count && !IS_ALIGNED((unsigned long)to, 8)) {
46 __raw_writeb(*(u8 *)from, to);
47 from++;
48 to++;
49 count--;
50 }
51
52 while (count >= 8) {
53 __raw_writeq(*(u64 *)from, to);
54 from += 8;
55 to += 8;
56 count -= 8;
57 }
58
59 while (count) {
60 __raw_writeb(*(u8 *)from, to);
61 from++;
62 to++;
63 count--;
64 }
65 }
66 EXPORT_SYMBOL(__memcpy_toio);
67
68 /*
69 * "memset" on IO memory space.
70 */
__memset_io(volatile void __iomem * dst,int c,size_t count)71 void __memset_io(volatile void __iomem *dst, int c, size_t count)
72 {
73 u64 qc = (u8)c;
74
75 qc |= qc << 8;
76 qc |= qc << 16;
77 qc |= qc << 32;
78
79 while (count && !IS_ALIGNED((unsigned long)dst, 8)) {
80 __raw_writeb(c, dst);
81 dst++;
82 count--;
83 }
84
85 while (count >= 8) {
86 __raw_writeq(qc, dst);
87 dst += 8;
88 count -= 8;
89 }
90
91 while (count) {
92 __raw_writeb(c, dst);
93 dst++;
94 count--;
95 }
96 }
97 EXPORT_SYMBOL(__memset_io);
98