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 cond_resched(); 87 } 88 89 if (cnt >= 2) { 90 unsigned short val; 91 pci_user_read_config_word(dev, pos, &val); 92 __put_user(cpu_to_le16(val), (__le16 __user *) buf); 93 buf += 2; 94 pos += 2; 95 cnt -= 2; 96 } 97 98 if (cnt) { 99 unsigned char val; 100 pci_user_read_config_byte(dev, pos, &val); 101 __put_user(val, buf); 102 pos++; 103 } 104 105 pci_config_pm_runtime_put(dev); 106 107 *ppos = pos; 108 return nbytes; 109 } 110 111 static ssize_t proc_bus_pci_write(struct file *file, const char __user *buf, 112 size_t nbytes, loff_t *ppos) 113 { 114 struct inode *ino = file_inode(file); 115 struct pci_dev *dev = pde_data(ino); 116 int pos = *ppos; 117 int size = dev->cfg_size; 118 int cnt, ret; 119 120 ret = security_locked_down(LOCKDOWN_PCI_ACCESS); 121 if (ret) 122 return ret; 123 124 if (pos >= size) 125 return 0; 126 if (nbytes >= size) 127 nbytes = size; 128 if (pos + nbytes > size) 129 nbytes = size - pos; 130 cnt = nbytes; 131 132 if (!access_ok(buf, cnt)) 133 return -EINVAL; 134 135 pci_config_pm_runtime_get(dev); 136 137 if ((pos & 1) && cnt) { 138 unsigned char val; 139 __get_user(val, buf); 140 pci_user_write_config_byte(dev, pos, val); 141 buf++; 142 pos++; 143 cnt--; 144 } 145 146 if ((pos & 3) && cnt > 2) { 147 __le16 val; 148 __get_user(val, (__le16 __user *) buf); 149 pci_user_write_config_word(dev, pos, le16_to_cpu(val)); 150 buf += 2; 151 pos += 2; 152 cnt -= 2; 153 } 154 155 while (cnt >= 4) { 156 __le32 val; 157 __get_user(val, (__le32 __user *) buf); 158 pci_user_write_config_dword(dev, pos, le32_to_cpu(val)); 159 buf += 4; 160 pos += 4; 161 cnt -= 4; 162 } 163 164 if (cnt >= 2) { 165 __le16 val; 166 __get_user(val, (__le16 __user *) buf); 167 pci_user_write_config_word(dev, pos, le16_to_cpu(val)); 168 buf += 2; 169 pos += 2; 170 cnt -= 2; 171 } 172 173 if (cnt) { 174 unsigned char val; 175 __get_user(val, buf); 176 pci_user_write_config_byte(dev, pos, val); 177 pos++; 178 } 179 180 pci_config_pm_runtime_put(dev); 181 182 *ppos = pos; 183 i_size_write(ino, dev->cfg_size); 184 return nbytes; 185 } 186 187 #ifdef HAVE_PCI_MMAP 188 struct pci_filp_private { 189 enum pci_mmap_state mmap_state; 190 int write_combine; 191 }; 192 #endif /* HAVE_PCI_MMAP */ 193 194 static long proc_bus_pci_ioctl(struct file *file, unsigned int cmd, 195 unsigned long arg) 196 { 197 struct pci_dev *dev = pde_data(file_inode(file)); 198 #ifdef HAVE_PCI_MMAP 199 struct pci_filp_private *fpriv = file->private_data; 200 #endif /* HAVE_PCI_MMAP */ 201 int ret = 0; 202 203 ret = security_locked_down(LOCKDOWN_PCI_ACCESS); 204 if (ret) 205 return ret; 206 207 switch (cmd) { 208 case PCIIOC_CONTROLLER: 209 ret = pci_domain_nr(dev->bus); 210 break; 211 212 #ifdef HAVE_PCI_MMAP 213 case PCIIOC_MMAP_IS_IO: 214 if (!arch_can_pci_mmap_io()) 215 return -EINVAL; 216 fpriv->mmap_state = pci_mmap_io; 217 break; 218 219 case PCIIOC_MMAP_IS_MEM: 220 fpriv->mmap_state = pci_mmap_mem; 221 break; 222 223 case PCIIOC_WRITE_COMBINE: 224 if (arch_can_pci_mmap_wc()) { 225 if (arg) 226 fpriv->write_combine = 1; 227 else 228 fpriv->write_combine = 0; 229 break; 230 } 231 /* If arch decided it can't, fall through... */ 232 fallthrough; 233 #endif /* HAVE_PCI_MMAP */ 234 default: 235 ret = -EINVAL; 236 break; 237 } 238 239 return ret; 240 } 241 242 #ifdef HAVE_PCI_MMAP 243 static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma) 244 { 245 struct pci_dev *dev = pde_data(file_inode(file)); 246 struct pci_filp_private *fpriv = file->private_data; 247 resource_size_t start, end; 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 } 277 278 if (dev->resource[i].flags & IORESOURCE_MEM && 279 iomem_is_exclusive(dev->resource[i].start)) 280 return -EINVAL; 281 282 pci_resource_to_user(dev, i, &dev->resource[i], &start, &end); 283 284 /* Adjust vm_pgoff to be the offset within the resource */ 285 vma->vm_pgoff -= start >> PAGE_SHIFT; 286 ret = pci_mmap_resource_range(dev, i, vma, 287 fpriv->mmap_state, write_combine); 288 if (ret < 0) 289 return ret; 290 291 return 0; 292 } 293 294 static int proc_bus_pci_open(struct inode *inode, struct file *file) 295 { 296 struct pci_filp_private *fpriv = kmalloc(sizeof(*fpriv), GFP_KERNEL); 297 298 if (!fpriv) 299 return -ENOMEM; 300 301 fpriv->mmap_state = pci_mmap_io; 302 fpriv->write_combine = 0; 303 304 file->private_data = fpriv; 305 file->f_mapping = iomem_get_mapping(); 306 307 return 0; 308 } 309 310 static int proc_bus_pci_release(struct inode *inode, struct file *file) 311 { 312 kfree(file->private_data); 313 file->private_data = NULL; 314 315 return 0; 316 } 317 #endif /* HAVE_PCI_MMAP */ 318 319 static const struct proc_ops proc_bus_pci_ops = { 320 .proc_lseek = proc_bus_pci_lseek, 321 .proc_read = proc_bus_pci_read, 322 .proc_write = proc_bus_pci_write, 323 .proc_ioctl = proc_bus_pci_ioctl, 324 #ifdef CONFIG_COMPAT 325 .proc_compat_ioctl = proc_bus_pci_ioctl, 326 #endif 327 #ifdef HAVE_PCI_MMAP 328 .proc_open = proc_bus_pci_open, 329 .proc_release = proc_bus_pci_release, 330 .proc_mmap = proc_bus_pci_mmap, 331 #ifdef HAVE_ARCH_PCI_GET_UNMAPPED_AREA 332 .proc_get_unmapped_area = get_pci_unmapped_area, 333 #endif /* HAVE_ARCH_PCI_GET_UNMAPPED_AREA */ 334 #endif /* HAVE_PCI_MMAP */ 335 }; 336 337 /* iterator */ 338 static void *pci_seq_start(struct seq_file *m, loff_t *pos) 339 { 340 struct pci_dev *dev = NULL; 341 loff_t n = *pos; 342 343 for_each_pci_dev(dev) { 344 if (!n--) 345 break; 346 } 347 return dev; 348 } 349 350 static void *pci_seq_next(struct seq_file *m, void *v, loff_t *pos) 351 { 352 struct pci_dev *dev = v; 353 354 (*pos)++; 355 dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev); 356 return dev; 357 } 358 359 static void pci_seq_stop(struct seq_file *m, void *v) 360 { 361 if (v) { 362 struct pci_dev *dev = v; 363 pci_dev_put(dev); 364 } 365 } 366 367 static int show_device(struct seq_file *m, void *v) 368 { 369 const struct pci_dev *dev = v; 370 const struct pci_driver *drv; 371 int i; 372 373 if (dev == NULL) 374 return 0; 375 376 drv = pci_dev_driver(dev); 377 seq_printf(m, "%02x%02x\t%04x%04x\t%x", 378 dev->bus->number, 379 dev->devfn, 380 dev->vendor, 381 dev->device, 382 dev->irq); 383 384 /* only print standard and ROM resources to preserve compatibility */ 385 for (i = 0; i <= PCI_ROM_RESOURCE; i++) { 386 resource_size_t start, end; 387 pci_resource_to_user(dev, i, &dev->resource[i], &start, &end); 388 seq_printf(m, "\t%16llx", 389 (unsigned long long)(start | 390 (dev->resource[i].flags & PCI_REGION_FLAG_MASK))); 391 } 392 for (i = 0; i <= PCI_ROM_RESOURCE; i++) { 393 resource_size_t start, end; 394 pci_resource_to_user(dev, i, &dev->resource[i], &start, &end); 395 seq_printf(m, "\t%16llx", 396 dev->resource[i].start < dev->resource[i].end ? 397 (unsigned long long)(end - start) + 1 : 0); 398 } 399 seq_putc(m, '\t'); 400 if (drv) 401 seq_puts(m, drv->name); 402 seq_putc(m, '\n'); 403 return 0; 404 } 405 406 static const struct seq_operations proc_bus_pci_devices_op = { 407 .start = pci_seq_start, 408 .next = pci_seq_next, 409 .stop = pci_seq_stop, 410 .show = show_device 411 }; 412 413 static struct proc_dir_entry *proc_bus_pci_dir; 414 415 int pci_proc_attach_device(struct pci_dev *dev) 416 { 417 struct pci_bus *bus = dev->bus; 418 struct proc_dir_entry *e; 419 char name[16]; 420 421 if (!proc_initialized) 422 return -EACCES; 423 424 if (!bus->procdir) { 425 if (pci_proc_domain(bus)) { 426 sprintf(name, "%04x:%02x", pci_domain_nr(bus), 427 bus->number); 428 } else { 429 sprintf(name, "%02x", bus->number); 430 } 431 bus->procdir = proc_mkdir(name, proc_bus_pci_dir); 432 if (!bus->procdir) 433 return -ENOMEM; 434 } 435 436 sprintf(name, "%02x.%x", PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn)); 437 e = proc_create_data(name, S_IFREG | S_IRUGO | S_IWUSR, bus->procdir, 438 &proc_bus_pci_ops, dev); 439 if (!e) 440 return -ENOMEM; 441 proc_set_size(e, dev->cfg_size); 442 dev->procent = e; 443 444 return 0; 445 } 446 447 int pci_proc_detach_device(struct pci_dev *dev) 448 { 449 proc_remove(dev->procent); 450 dev->procent = NULL; 451 return 0; 452 } 453 454 int pci_proc_detach_bus(struct pci_bus *bus) 455 { 456 proc_remove(bus->procdir); 457 return 0; 458 } 459 460 static int __init pci_proc_init(void) 461 { 462 struct pci_dev *dev = NULL; 463 proc_bus_pci_dir = proc_mkdir("bus/pci", NULL); 464 proc_create_seq("devices", 0, proc_bus_pci_dir, 465 &proc_bus_pci_devices_op); 466 proc_initialized = 1; 467 for_each_pci_dev(dev) 468 pci_proc_attach_device(dev); 469 470 return 0; 471 } 472 device_initcall(pci_proc_init); 473