arm64/kernel/io.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Based on arch/arm/kernel/io.c
0004  *
0005  * Copyright (C) 2012 ARM Ltd.
0006  */
0007
0008 #include <linux/export.h>
0009 #include <linux/types.h>
0010 #include <linux/io.h>
0011
0012 /*
0013  * Copy data from IO memory space to "real" memory space.
0014  */
0015 void __memcpy_fromio(void *to, const volatile void __iomem *from, size_t count)
0016 {
0017     while (count && !IS_ALIGNED((unsigned long)from, 8)) {
0018         *(u8 *)to = __raw_readb(from);
0019         from++;
0020         to++;
0021         count--;
0022     }
0023
0024     while (count >= 8) {
0025         *(u64 *)to = __raw_readq(from);
0026         from += 8;
0027         to += 8;
0028         count -= 8;
0029     }
0030
0031     while (count) {
0032         *(u8 *)to = __raw_readb(from);
0033         from++;
0034         to++;
0035         count--;
0036     }
0037 }
0038 EXPORT_SYMBOL(__memcpy_fromio);
0039
0040 /*
0041  * Copy data from "real" memory space to IO memory space.
0042  */
0043 void __memcpy_toio(volatile void __iomem *to, const void *from, size_t count)
0044 {
0045     while (count && !IS_ALIGNED((unsigned long)to, 8)) {
0046         __raw_writeb(*(u8 *)from, to);
0047         from++;
0048         to++;
0049         count--;
0050     }
0051
0052     while (count >= 8) {
0053         __raw_writeq(*(u64 *)from, to);
0054         from += 8;
0055         to += 8;
0056         count -= 8;
0057     }
0058
0059     while (count) {
0060         __raw_writeb(*(u8 *)from, to);
0061         from++;
0062         to++;
0063         count--;
0064     }
0065 }
0066 EXPORT_SYMBOL(__memcpy_toio);
0067
0068 /*
0069  * "memset" on IO memory space.
0070  */
0071 void __memset_io(volatile void __iomem *dst, int c, size_t count)
0072 {
0073     u64 qc = (u8)c;
0074
0075     qc |= qc << 8;
0076     qc |= qc << 16;
0077     qc |= qc << 32;
0078
0079     while (count && !IS_ALIGNED((unsigned long)dst, 8)) {
0080         __raw_writeb(c, dst);
0081         dst++;
0082         count--;
0083     }
0084
0085     while (count >= 8) {
0086         __raw_writeq(qc, dst);
0087         dst += 8;
0088         count -= 8;
0089     }
0090
0091     while (count) {
0092         __raw_writeb(c, dst);
0093         dst++;
0094         count--;
0095     }
0096 }
0097 EXPORT_SYMBOL(__memset_io);