1 /* 2 * (C) Copyright IBM Corporation 2007 3 * All Rights Reserved. 4 * 5 * Permission is hereby granted, free of charge, to any person obtaining a 6 * copy of this software and associated documentation files (the "Software"), 7 * to deal in the Software without restriction, including without limitation 8 * on the rights to use, copy, modify, merge, publish, distribute, sub 9 * license, and/or sell copies of the Software, and to permit persons to whom 10 * the Software is furnished to do so, subject to the following conditions: 11 * 12 * The above copyright notice and this permission notice (including the next 13 * paragraph) shall be included in all copies or substantial portions of the 14 * Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL 19 * IBM AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 22 * DEALINGS IN THE SOFTWARE. 23 */ 24 25 /** 26 * \file linux_devmem.c 27 * Access PCI subsystem using Linux's the old /dev/mem interface. 28 * 29 * \note 30 * This is currently just a skeleton. It only includes the /dev/mem based 31 * function for reading the device ROM. 32 * 33 * \author Ian Romanick <[email protected]> 34 */ 35 36 #define _GNU_SOURCE 37 38 #include <stdlib.h> 39 #include <string.h> 40 #include <stdio.h> 41 #include <unistd.h> 42 #include <sys/types.h> 43 #include <sys/stat.h> 44 #include <fcntl.h> 45 #include <sys/mman.h> 46 #include <dirent.h> 47 #include <errno.h> 48 49 #include "pciaccess.h" 50 #include "pciaccess_private.h" 51 #include "linux_devmem.h" 52 53 /** 54 * Read a device's expansion ROM using /dev/mem. 55 * 56 * \note 57 * This function could probably be used, as-is, on other platforms that have 58 * a /dev/mem interface. 59 * 60 * \bugs 61 * Before using the VGA special case code, this function should check that 62 * VGA access are routed to the device. Right? 63 */ 64 _pci_hidden int 65 pci_device_linux_devmem_read_rom(struct pci_device *dev, void *buffer) 66 { 67 struct pci_device_private *priv = (struct pci_device_private *) dev; 68 int fd; 69 int err = 0; 70 uint32_t rom_base_tmp; 71 pciaddr_t rom_base; 72 pciaddr_t rom_size; 73 int PCI_ROM; 74 75 76 /* Handle some special cases of legacy devices. 77 */ 78 if (priv->base.rom_size == 0) { 79 /* VGA ROMs are supposed to be at 0xC0000. 80 */ 81 if ((priv->base.device_class & 0x00ffff00) == 0x000030000) { 82 rom_base = 0x000C0000; 83 rom_size = 0x00010000; 84 PCI_ROM = 0; 85 } 86 else { 87 /* "Function not implemented." 88 */ 89 return ENOSYS; 90 } 91 } 92 else { 93 rom_base = priv->rom_base; 94 rom_size = priv->base.rom_size; 95 PCI_ROM = 1; 96 } 97 98 99 100 /* Enable the device's ROM. 101 */ 102 if (PCI_ROM) { 103 err = pci_device_cfg_read_u32(& priv->base, & rom_base_tmp, 48); 104 if (err) { 105 return err; 106 } 107 108 if ((rom_base_tmp & 0x000000001) == 0) { 109 err = pci_device_cfg_write_u32(& priv->base, 110 rom_base_tmp | 1, 48); 111 if (err) { 112 return err; 113 } 114 } 115 } 116 117 118 /* Read the portion of /dev/mem that corresponds to the device's ROM. 119 */ 120 fd = open("/dev/mem", O_RDONLY, 0); 121 if (fd < 0) { 122 err = errno; 123 } 124 else { 125 size_t bytes; 126 127 for (bytes = 0; bytes < priv->base.rom_size; /* empty */) { 128 const ssize_t got = pread(fd, buffer, rom_size - bytes, 129 rom_base + bytes); 130 if (got == -1) { 131 err = errno; 132 break; 133 } 134 135 bytes += got; 136 } 137 138 close(fd); 139 } 140 141 142 /* Disable the device's ROM. 143 */ 144 if (PCI_ROM && ((rom_base_tmp & 0x000000001) == 0)) { 145 const int tmp_err = pci_device_cfg_write_u32(& priv->base, 146 rom_base_tmp, 48); 147 148 /* Prefer to return the first error that occured. 149 */ 150 if (err == 0) { 151 err = tmp_err; 152 } 153 } 154 155 return err; 156 } 157