1 /* 2 * The PCI Library -- Configuration Access via /proc/bus/pci 3 * 4 * Copyright (c) 1997--2023 Martin Mares <[email protected]> 5 * 6 * Can be freely distributed and used under the terms of the GNU GPL v2+. 7 * 8 * SPDX-License-Identifier: GPL-2.0-or-later 9 */ 10 11 #define _GNU_SOURCE 12 13 #include <stdio.h> 14 #include <string.h> 15 #include <unistd.h> 16 #include <ctype.h> 17 #include <errno.h> 18 #include <fcntl.h> 19 #include <sys/types.h> 20 21 #include "internal.h" 22 23 static void 24 proc_config(struct pci_access *a) 25 { 26 pci_define_param(a, "proc.path", PCI_PATH_PROC_BUS_PCI, "Path to the procfs bus tree"); 27 } 28 29 static int 30 proc_detect(struct pci_access *a) 31 { 32 char *name = pci_get_param(a, "proc.path"); 33 34 if (access(name, R_OK)) 35 { 36 a->warning("Cannot open %s", name); 37 return 0; 38 } 39 a->debug("...using %s", name); 40 return 1; 41 } 42 43 static void 44 proc_init(struct pci_access *a) 45 { 46 a->fd = -1; 47 } 48 49 static void 50 proc_cleanup(struct pci_access *a) 51 { 52 if (a->fd >= 0) 53 { 54 close(a->fd); 55 a->fd = -1; 56 } 57 } 58 59 static void 60 proc_scan(struct pci_access *a) 61 { 62 FILE *f; 63 char buf[512]; 64 65 if (snprintf(buf, sizeof(buf), "%s/devices", pci_get_param(a, "proc.path")) == sizeof(buf)) 66 a->error("File name too long"); 67 f = fopen(buf, "r"); 68 if (!f) 69 a->error("Cannot open %s", buf); 70 while (fgets(buf, sizeof(buf)-1, f)) 71 { 72 struct pci_dev *d = pci_alloc_dev(a); 73 unsigned int dfn, vend, cnt, known; 74 char *driver; 75 int offset; 76 77 #define F " " PCIADDR_T_FMT 78 cnt = sscanf(buf, "%x %x %x" F F F F F F F F F F F F F F "%n", 79 &dfn, 80 &vend, 81 &d->irq, 82 &d->base_addr[0], 83 &d->base_addr[1], 84 &d->base_addr[2], 85 &d->base_addr[3], 86 &d->base_addr[4], 87 &d->base_addr[5], 88 &d->rom_base_addr, 89 &d->size[0], 90 &d->size[1], 91 &d->size[2], 92 &d->size[3], 93 &d->size[4], 94 &d->size[5], 95 &d->rom_size, 96 &offset); 97 #undef F 98 if (cnt != 9 && cnt != 10 && cnt != 17) 99 a->error("proc: parse error (read only %d items)", cnt); 100 d->bus = dfn >> 8U; 101 d->dev = PCI_SLOT(dfn & 0xff); 102 d->func = PCI_FUNC(dfn & 0xff); 103 d->vendor_id = vend >> 16U; 104 d->device_id = vend & 0xffff; 105 known = 0; 106 if (!a->buscentric) 107 { 108 known |= PCI_FILL_IDENT | PCI_FILL_IRQ | PCI_FILL_BASES; 109 if (cnt >= 10) 110 known |= PCI_FILL_ROM_BASE; 111 if (cnt >= 17) 112 known |= PCI_FILL_SIZES; 113 } 114 if (cnt >= 17) 115 { 116 while (buf[offset] && isspace(buf[offset])) 117 ++offset; 118 driver = &buf[offset]; 119 while (buf[offset] && !isspace(buf[offset])) 120 ++offset; 121 buf[offset] = '\0'; 122 if (driver[0]) 123 { 124 pci_set_property(d, PCI_FILL_DRIVER, driver); 125 known |= PCI_FILL_DRIVER; 126 } 127 } 128 d->known_fields = known; 129 pci_link_dev(a, d); 130 } 131 fclose(f); 132 } 133 134 static int 135 proc_setup(struct pci_dev *d, int rw) 136 { 137 struct pci_access *a = d->access; 138 139 if (a->cached_dev != d || a->fd_rw < rw) 140 { 141 char buf[1024]; 142 int e; 143 if (a->fd >= 0) 144 close(a->fd); 145 e = snprintf(buf, sizeof(buf), "%s/%02x/%02x.%d", 146 pci_get_param(a, "proc.path"), 147 d->bus, d->dev, d->func); 148 if (e < 0 || e >= (int) sizeof(buf)) 149 a->error("File name too long"); 150 a->fd_rw = a->writeable || rw; 151 a->fd = open(buf, a->fd_rw ? O_RDWR : O_RDONLY); 152 if (a->fd < 0) 153 { 154 e = snprintf(buf, sizeof(buf), "%s/%04x:%02x/%02x.%d", 155 pci_get_param(a, "proc.path"), 156 d->domain, d->bus, d->dev, d->func); 157 if (e < 0 || e >= (int) sizeof(buf)) 158 a->error("File name too long"); 159 a->fd = open(buf, a->fd_rw ? O_RDWR : O_RDONLY); 160 } 161 if (a->fd < 0) 162 a->warning("Cannot open %s", buf); 163 a->cached_dev = d; 164 } 165 return a->fd; 166 } 167 168 static int 169 proc_read(struct pci_dev *d, int pos, byte *buf, int len) 170 { 171 int fd = proc_setup(d, 0); 172 int res; 173 174 if (fd < 0) 175 return 0; 176 res = pread(fd, buf, len, pos); 177 if (res < 0) 178 { 179 d->access->warning("proc_read: read failed: %s", strerror(errno)); 180 return 0; 181 } 182 else if (res != len) 183 return 0; 184 return 1; 185 } 186 187 static int 188 proc_write(struct pci_dev *d, int pos, byte *buf, int len) 189 { 190 int fd = proc_setup(d, 1); 191 int res; 192 193 if (fd < 0) 194 return 0; 195 res = pwrite(fd, buf, len, pos); 196 if (res < 0) 197 { 198 d->access->warning("proc_write: write failed: %s", strerror(errno)); 199 return 0; 200 } 201 else if (res != len) 202 { 203 d->access->warning("proc_write: tried to write %d bytes at %d, but only %d succeeded", len, pos, res); 204 return 0; 205 } 206 return 1; 207 } 208 209 static void 210 proc_cleanup_dev(struct pci_dev *d) 211 { 212 if (d->access->cached_dev == d) 213 d->access->cached_dev = NULL; 214 } 215 216 struct pci_methods pm_linux_proc = { 217 "linux-proc", 218 "The proc file system on Linux", 219 proc_config, 220 proc_detect, 221 proc_init, 222 proc_cleanup, 223 proc_scan, 224 pci_generic_fill_info, 225 proc_read, 226 proc_write, 227 NULL, /* read_vpd */ 228 NULL, /* init_dev */ 229 proc_cleanup_dev 230 }; 231