cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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io.c (1602B)

      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 */
     15void __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}
     38EXPORT_SYMBOL(__memcpy_fromio);
     39
     40/*
     41 * Copy data from "real" memory space to IO memory space.
     42 */
     43void __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}
     66EXPORT_SYMBOL(__memcpy_toio);
     67
     68/*
     69 * "memset" on IO memory space.
     70 */
     71void __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}
     97EXPORT_SYMBOL(__memset_io);