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 - 2021, 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 18 ACPI_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 ******************************************************************************/ 40 static 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 63 void *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 *****************************************************************************/ 108 109 void 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 } 118