1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Procfs interface for the PCI bus 4 * 5 * Copyright (c) 1997--1999 Martin Mares <mj@ucw.cz> 6 */ 7 8 #include <linux/init.h> 9 #include <linux/pci.h> 10 #include <linux/slab.h> 11 #include <linux/module.h> 12 #include <linux/proc_fs.h> 13 #include <linux/seq_file.h> 14 #include <linux/capability.h> 15 #include <linux/uaccess.h> 16 #include <linux/security.h> 17 #include <asm/byteorder.h> 18 #include "pci.h" 19 20 static int proc_initialized; /* = 0 */ 21 22 static loff_t proc_bus_pci_lseek(struct file *file, loff_t off, int whence) 23 { 24 struct pci_dev *dev = PDE_DATA(file_inode(file)); 25 return fixed_size_llseek(file, off, whence, dev->cfg_size); 26 } 27 28 static ssize_t proc_bus_pci_read(struct file *file, char __user *buf, 29 size_t nbytes, loff_t *ppos) 30 { 31 struct pci_dev *dev = PDE_DATA(file_inode(file)); 32 unsigned int pos = *ppos; 33 unsigned int cnt, size; 34 35 /* 36 * Normal users can read only the standardized portion of the 37 * configuration space as several chips lock up when trying to read 38 * undefined locations (think of Intel PIIX4 as a typical example). 39 */ 40 41 if (capable(CAP_SYS_ADMIN)) 42 size = dev->cfg_size; 43 else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) 44 size = 128; 45 else 46 size = 64; 47 48 if (pos >= size) 49 return 0; 50 if (nbytes >= size) 51 nbytes = size; 52 if (pos + nbytes > size) 53 nbytes = size - pos; 54 cnt = nbytes; 55 56 if (!access_ok(buf, cnt)) 57 return -EINVAL; 58 59 pci_config_pm_runtime_get(dev); 60 61 if ((pos & 1) && cnt) { 62 unsigned char val; 63 pci_user_read_config_byte(dev, pos, &val); 64 __put_user(val, buf); 65 buf++; 66 pos++; 67 cnt--; 68 } 69 70 if ((pos & 3) && cnt > 2) { 71 unsigned short val; 72 pci_user_read_config_word(dev, pos, &val); 73 __put_user(cpu_to_le16(val), (__le16 __user *) buf); 74 buf += 2; 75 pos += 2; 76 cnt -= 2; 77 } 78 79 while (cnt >= 4) { 80 unsigned int val; 81 pci_user_read_config_dword(dev, pos, &val); 82 __put_user(cpu_to_le32(val), (__le32 __user *) buf); 83 buf += 4; 84 pos += 4; 85 cnt -= 4; 86 } 87 88 if (cnt >= 2) { 89 unsigned short val; 90 pci_user_read_config_word(dev, pos, &val); 91 __put_user(cpu_to_le16(val), (__le16 __user *) buf); 92 buf += 2; 93 pos += 2; 94 cnt -= 2; 95 } 96 97 if (cnt) { 98 unsigned char val; 99 pci_user_read_config_byte(dev, pos, &val); 100 __put_user(val, buf); 101 buf++; 102 pos++; 103 cnt--; 104 } 105 106 pci_config_pm_runtime_put(dev); 107 108 *ppos = pos; 109 return nbytes; 110 } 111 112 static ssize_t proc_bus_pci_write(struct file *file, const char __user *buf, 113 size_t nbytes, loff_t *ppos) 114 { 115 struct inode *ino = file_inode(file); 116 struct pci_dev *dev = PDE_DATA(ino); 117 int pos = *ppos; 118 int size = dev->cfg_size; 119 int cnt, ret; 120 121 ret = security_locked_down(LOCKDOWN_PCI_ACCESS); 122 if (ret) 123 return ret; 124 125 if (pos >= size) 126 return 0; 127 if (nbytes >= size) 128 nbytes = size; 129 if (pos + nbytes > size) 130 nbytes = size - pos; 131 cnt = nbytes; 132 133 if (!access_ok(buf, cnt)) 134 return -EINVAL; 135 136 pci_config_pm_runtime_get(dev); 137 138 if ((pos & 1) && cnt) { 139 unsigned char val; 140 __get_user(val, buf); 141 pci_user_write_config_byte(dev, pos, val); 142 buf++; 143 pos++; 144 cnt--; 145 } 146 147 if ((pos & 3) && cnt > 2) { 148 __le16 val; 149 __get_user(val, (__le16 __user *) buf); 150 pci_user_write_config_word(dev, pos, le16_to_cpu(val)); 151 buf += 2; 152 pos += 2; 153 cnt -= 2; 154 } 155 156 while (cnt >= 4) { 157 __le32 val; 158 __get_user(val, (__le32 __user *) buf); 159 pci_user_write_config_dword(dev, pos, le32_to_cpu(val)); 160 buf += 4; 161 pos += 4; 162 cnt -= 4; 163 } 164 165 if (cnt >= 2) { 166 __le16 val; 167 __get_user(val, (__le16 __user *) buf); 168 pci_user_write_config_word(dev, pos, le16_to_cpu(val)); 169 buf += 2; 170 pos += 2; 171 cnt -= 2; 172 } 173 174 if (cnt) { 175 unsigned char val; 176 __get_user(val, buf); 177 pci_user_write_config_byte(dev, pos, val); 178 buf++; 179 pos++; 180 cnt--; 181 } 182 183 pci_config_pm_runtime_put(dev); 184 185 *ppos = pos; 186 i_size_write(ino, dev->cfg_size); 187 return nbytes; 188 } 189 190 struct pci_filp_private { 191 enum pci_mmap_state mmap_state; 192 int write_combine; 193 }; 194 195 static long proc_bus_pci_ioctl(struct file *file, unsigned int cmd, 196 unsigned long arg) 197 { 198 struct pci_dev *dev = PDE_DATA(file_inode(file)); 199 #ifdef HAVE_PCI_MMAP 200 struct pci_filp_private *fpriv = file->private_data; 201 #endif /* HAVE_PCI_MMAP */ 202 int ret = 0; 203 204 ret = security_locked_down(LOCKDOWN_PCI_ACCESS); 205 if (ret) 206 return ret; 207 208 switch (cmd) { 209 case PCIIOC_CONTROLLER: 210 ret = pci_domain_nr(dev->bus); 211 break; 212 213 #ifdef HAVE_PCI_MMAP 214 case PCIIOC_MMAP_IS_IO: 215 if (!arch_can_pci_mmap_io()) 216 return -EINVAL; 217 fpriv->mmap_state = pci_mmap_io; 218 break; 219 220 case PCIIOC_MMAP_IS_MEM: 221 fpriv->mmap_state = pci_mmap_mem; 222 break; 223 224 case PCIIOC_WRITE_COMBINE: 225 if (arch_can_pci_mmap_wc()) { 226 if (arg) 227 fpriv->write_combine = 1; 228 else 229 fpriv->write_combine = 0; 230 break; 231 } 232 /* If arch decided it can't, fall through... */ 233 #endif /* HAVE_PCI_MMAP */ 234 /* fall through */ 235 default: 236 ret = -EINVAL; 237 break; 238 } 239 240 return ret; 241 } 242 243 #ifdef HAVE_PCI_MMAP 244 static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma) 245 { 246 struct pci_dev *dev = PDE_DATA(file_inode(file)); 247 struct pci_filp_private *fpriv = file->private_data; 248 int i, ret, write_combine = 0, res_bit = IORESOURCE_MEM; 249 250 if (!capable(CAP_SYS_RAWIO) || 251 security_locked_down(LOCKDOWN_PCI_ACCESS)) 252 return -EPERM; 253 254 if (fpriv->mmap_state == pci_mmap_io) { 255 if (!arch_can_pci_mmap_io()) 256 return -EINVAL; 257 res_bit = IORESOURCE_IO; 258 } 259 260 /* Make sure the caller is mapping a real resource for this device */ 261 for (i = 0; i < PCI_STD_NUM_BARS; i++) { 262 if (dev->resource[i].flags & res_bit && 263 pci_mmap_fits(dev, i, vma, PCI_MMAP_PROCFS)) 264 break; 265 } 266 267 if (i >= PCI_STD_NUM_BARS) 268 return -ENODEV; 269 270 if (fpriv->mmap_state == pci_mmap_mem && 271 fpriv->write_combine) { 272 if (dev->resource[i].flags & IORESOURCE_PREFETCH) 273 write_combine = 1; 274 else 275 return -EINVAL; 276 } 277 ret = pci_mmap_page_range(dev, i, vma, 278 fpriv->mmap_state, write_combine); 279 if (ret < 0) 280 return ret; 281 282 return 0; 283 } 284 285 static int proc_bus_pci_open(struct inode *inode, struct file *file) 286 { 287 struct pci_filp_private *fpriv = kmalloc(sizeof(*fpriv), GFP_KERNEL); 288 289 if (!fpriv) 290 return -ENOMEM; 291 292 fpriv->mmap_state = pci_mmap_io; 293 fpriv->write_combine = 0; 294 295 file->private_data = fpriv; 296 297 return 0; 298 } 299 300 static int proc_bus_pci_release(struct inode *inode, struct file *file) 301 { 302 kfree(file->private_data); 303 file->private_data = NULL; 304 305 return 0; 306 } 307 #endif /* HAVE_PCI_MMAP */ 308 309 static const struct file_operations proc_bus_pci_operations = { 310 .owner = THIS_MODULE, 311 .llseek = proc_bus_pci_lseek, 312 .read = proc_bus_pci_read, 313 .write = proc_bus_pci_write, 314 .unlocked_ioctl = proc_bus_pci_ioctl, 315 .compat_ioctl = proc_bus_pci_ioctl, 316 #ifdef HAVE_PCI_MMAP 317 .open = proc_bus_pci_open, 318 .release = proc_bus_pci_release, 319 .mmap = proc_bus_pci_mmap, 320 #ifdef HAVE_ARCH_PCI_GET_UNMAPPED_AREA 321 .get_unmapped_area = get_pci_unmapped_area, 322 #endif /* HAVE_ARCH_PCI_GET_UNMAPPED_AREA */ 323 #endif /* HAVE_PCI_MMAP */ 324 }; 325 326 /* iterator */ 327 static void *pci_seq_start(struct seq_file *m, loff_t *pos) 328 { 329 struct pci_dev *dev = NULL; 330 loff_t n = *pos; 331 332 for_each_pci_dev(dev) { 333 if (!n--) 334 break; 335 } 336 return dev; 337 } 338 339 static void *pci_seq_next(struct seq_file *m, void *v, loff_t *pos) 340 { 341 struct pci_dev *dev = v; 342 343 (*pos)++; 344 dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev); 345 return dev; 346 } 347 348 static void pci_seq_stop(struct seq_file *m, void *v) 349 { 350 if (v) { 351 struct pci_dev *dev = v; 352 pci_dev_put(dev); 353 } 354 } 355 356 static int show_device(struct seq_file *m, void *v) 357 { 358 const struct pci_dev *dev = v; 359 const struct pci_driver *drv; 360 int i; 361 362 if (dev == NULL) 363 return 0; 364 365 drv = pci_dev_driver(dev); 366 seq_printf(m, "%02x%02x\t%04x%04x\t%x", 367 dev->bus->number, 368 dev->devfn, 369 dev->vendor, 370 dev->device, 371 dev->irq); 372 373 /* only print standard and ROM resources to preserve compatibility */ 374 for (i = 0; i <= PCI_ROM_RESOURCE; i++) { 375 resource_size_t start, end; 376 pci_resource_to_user(dev, i, &dev->resource[i], &start, &end); 377 seq_printf(m, "\t%16llx", 378 (unsigned long long)(start | 379 (dev->resource[i].flags & PCI_REGION_FLAG_MASK))); 380 } 381 for (i = 0; i <= PCI_ROM_RESOURCE; i++) { 382 resource_size_t start, end; 383 pci_resource_to_user(dev, i, &dev->resource[i], &start, &end); 384 seq_printf(m, "\t%16llx", 385 dev->resource[i].start < dev->resource[i].end ? 386 (unsigned long long)(end - start) + 1 : 0); 387 } 388 seq_putc(m, '\t'); 389 if (drv) 390 seq_puts(m, drv->name); 391 seq_putc(m, '\n'); 392 return 0; 393 } 394 395 static const struct seq_operations proc_bus_pci_devices_op = { 396 .start = pci_seq_start, 397 .next = pci_seq_next, 398 .stop = pci_seq_stop, 399 .show = show_device 400 }; 401 402 static struct proc_dir_entry *proc_bus_pci_dir; 403 404 int pci_proc_attach_device(struct pci_dev *dev) 405 { 406 struct pci_bus *bus = dev->bus; 407 struct proc_dir_entry *e; 408 char name[16]; 409 410 if (!proc_initialized) 411 return -EACCES; 412 413 if (!bus->procdir) { 414 if (pci_proc_domain(bus)) { 415 sprintf(name, "%04x:%02x", pci_domain_nr(bus), 416 bus->number); 417 } else { 418 sprintf(name, "%02x", bus->number); 419 } 420 bus->procdir = proc_mkdir(name, proc_bus_pci_dir); 421 if (!bus->procdir) 422 return -ENOMEM; 423 } 424 425 sprintf(name, "%02x.%x", PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn)); 426 e = proc_create_data(name, S_IFREG | S_IRUGO | S_IWUSR, bus->procdir, 427 &proc_bus_pci_operations, dev); 428 if (!e) 429 return -ENOMEM; 430 proc_set_size(e, dev->cfg_size); 431 dev->procent = e; 432 433 return 0; 434 } 435 436 int pci_proc_detach_device(struct pci_dev *dev) 437 { 438 proc_remove(dev->procent); 439 dev->procent = NULL; 440 return 0; 441 } 442 443 int pci_proc_detach_bus(struct pci_bus *bus) 444 { 445 proc_remove(bus->procdir); 446 return 0; 447 } 448 449 static int __init pci_proc_init(void) 450 { 451 struct pci_dev *dev = NULL; 452 proc_bus_pci_dir = proc_mkdir("bus/pci", NULL); 453 proc_create_seq("devices", 0, proc_bus_pci_dir, 454 &proc_bus_pci_devices_op); 455 proc_initialized = 1; 456 for_each_pci_dev(dev) 457 pci_proc_attach_device(dev); 458 459 return 0; 460 } 461 device_initcall(pci_proc_init); 462