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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osunixmap.c (3183B)

      1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
      2/******************************************************************************
      3 *
      4 * Module Name: osunixmap - Unix OSL for file mappings
      5 *
      6 * Copyright (C) 2000 - 2022, Intel Corp.
      7 *
      8 *****************************************************************************/
      9
     10#include "acpidump.h"
     11#include <unistd.h>
     12#include <sys/mman.h>
     13#ifdef _free_BSD
     14#include <sys/param.h>
     15#endif
     16
     17#define _COMPONENT          ACPI_OS_SERVICES
     18ACPI_MODULE_NAME("osunixmap")
     19
     20#ifndef O_BINARY
     21#define O_BINARY 0
     22#endif
     23#if defined(_dragon_fly) || defined(_free_BSD) || defined(_QNX)
     24#define MMAP_FLAGS          MAP_SHARED
     25#else
     26#define MMAP_FLAGS          MAP_PRIVATE
     27#endif
     28#define SYSTEM_MEMORY       "/dev/mem"
     29/*******************************************************************************
     30 *
     31 * FUNCTION:    acpi_os_get_page_size
     32 *
     33 * PARAMETERS:  None
     34 *
     35 * RETURN:      Page size of the platform.
     36 *
     37 * DESCRIPTION: Obtain page size of the platform.
     38 *
     39 ******************************************************************************/
     40static acpi_size acpi_os_get_page_size(void)
     41{
     42
     43#ifdef PAGE_SIZE
     44	return PAGE_SIZE;
     45#else
     46	return sysconf(_SC_PAGESIZE);
     47#endif
     48}
     49
     50/******************************************************************************
     51 *
     52 * FUNCTION:    acpi_os_map_memory
     53 *
     54 * PARAMETERS:  where               - Physical address of memory to be mapped
     55 *              length              - How much memory to map
     56 *
     57 * RETURN:      Pointer to mapped memory. Null on error.
     58 *
     59 * DESCRIPTION: Map physical memory into local address space.
     60 *
     61 *****************************************************************************/
     62
     63void *acpi_os_map_memory(acpi_physical_address where, acpi_size length)
     64{
     65	u8 *mapped_memory;
     66	acpi_physical_address offset;
     67	acpi_size page_size;
     68	int fd;
     69
     70	fd = open(SYSTEM_MEMORY, O_RDONLY | O_BINARY);
     71	if (fd < 0) {
     72		fprintf(stderr, "Cannot open %s\n", SYSTEM_MEMORY);
     73		return (NULL);
     74	}
     75
     76	/* Align the offset to use mmap */
     77
     78	page_size = acpi_os_get_page_size();
     79	offset = where % page_size;
     80
     81	/* Map the table header to get the length of the full table */
     82
     83	mapped_memory = mmap(NULL, (length + offset), PROT_READ, MMAP_FLAGS,
     84			     fd, (where - offset));
     85	if (mapped_memory == MAP_FAILED) {
     86		fprintf(stderr, "Cannot map %s\n", SYSTEM_MEMORY);
     87		close(fd);
     88		return (NULL);
     89	}
     90
     91	close(fd);
     92	return (ACPI_CAST8(mapped_memory + offset));
     93}
     94
     95/******************************************************************************
     96 *
     97 * FUNCTION:    acpi_os_unmap_memory
     98 *
     99 * PARAMETERS:  where               - Logical address of memory to be unmapped
    100 *              length              - How much memory to unmap
    101 *
    102 * RETURN:      None.
    103 *
    104 * DESCRIPTION: Delete a previously created mapping. Where and Length must
    105 *              correspond to a previous mapping exactly.
    106 *
    107 *****************************************************************************/
    108
    109void acpi_os_unmap_memory(void *where, acpi_size length)
    110{
    111	acpi_physical_address offset;
    112	acpi_size page_size;
    113
    114	page_size = acpi_os_get_page_size();
    115	offset = ACPI_TO_INTEGER(where) % page_size;
    116	munmap((u8 *)where - offset, (length + offset));
    117}