drivers/pci/proc.c

   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                 fallthrough;
 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 proc_ops proc_bus_pci_ops = {
 310         .proc_lseek     = proc_bus_pci_lseek,
 311         .proc_read      = proc_bus_pci_read,
 312         .proc_write     = proc_bus_pci_write,
 313         .proc_ioctl     = proc_bus_pci_ioctl,
 314 #ifdef CONFIG_COMPAT
 315         .proc_compat_ioctl = proc_bus_pci_ioctl,
 316 #endif
 317 #ifdef HAVE_PCI_MMAP
 318         .proc_open      = proc_bus_pci_open,
 319         .proc_release   = proc_bus_pci_release,
 320         .proc_mmap      = proc_bus_pci_mmap,
 321 #ifdef HAVE_ARCH_PCI_GET_UNMAPPED_AREA
 322         .proc_get_unmapped_area = get_pci_unmapped_area,
 323 #endif /* HAVE_ARCH_PCI_GET_UNMAPPED_AREA */
 324 #endif /* HAVE_PCI_MMAP */
 325 };
 326
 327 /* iterator */
 328 static void *pci_seq_start(struct seq_file *m, loff_t *pos)
 329 {
 330         struct pci_dev *dev = NULL;
 331         loff_t n = *pos;
 332
 333         for_each_pci_dev(dev) {
 334                 if (!n--)
 335                         break;
 336         }
 337         return dev;
 338 }
 339
 340 static void *pci_seq_next(struct seq_file *m, void *v, loff_t *pos)
 341 {
 342         struct pci_dev *dev = v;
 343
 344         (*pos)++;
 345         dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev);
 346         return dev;
 347 }
 348
 349 static void pci_seq_stop(struct seq_file *m, void *v)
 350 {
 351         if (v) {
 352                 struct pci_dev *dev = v;
 353                 pci_dev_put(dev);
 354         }
 355 }
 356
 357 static int show_device(struct seq_file *m, void *v)
 358 {
 359         const struct pci_dev *dev = v;
 360         const struct pci_driver *drv;
 361         int i;
 362
 363         if (dev == NULL)
 364                 return 0;
 365
 366         drv = pci_dev_driver(dev);
 367         seq_printf(m, "%02x%02x\t%04x%04x\t%x",
 368                         dev->bus->number,
 369                         dev->devfn,
 370                         dev->vendor,
 371                         dev->device,
 372                         dev->irq);
 373
 374         /* only print standard and ROM resources to preserve compatibility */
 375         for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
 376                 resource_size_t start, end;
 377                 pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
 378                 seq_printf(m, "\t%16llx",
 379                         (unsigned long long)(start |
 380                         (dev->resource[i].flags & PCI_REGION_FLAG_MASK)));
 381         }
 382         for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
 383                 resource_size_t start, end;
 384                 pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
 385                 seq_printf(m, "\t%16llx",
 386                         dev->resource[i].start < dev->resource[i].end ?
 387                         (unsigned long long)(end - start) + 1 : 0);
 388         }
 389         seq_putc(m, '\t');
 390         if (drv)
 391                 seq_puts(m, drv->name);
 392         seq_putc(m, '\n');
 393         return 0;
 394 }
 395
 396 static const struct seq_operations proc_bus_pci_devices_op = {
 397         .start  = pci_seq_start,
 398         .next   = pci_seq_next,
 399         .stop   = pci_seq_stop,
 400         .show   = show_device
 401 };
 402
 403 static struct proc_dir_entry *proc_bus_pci_dir;
 404
 405 int pci_proc_attach_device(struct pci_dev *dev)
 406 {
 407         struct pci_bus *bus = dev->bus;
 408         struct proc_dir_entry *e;
 409         char name[16];
 410
 411         if (!proc_initialized)
 412                 return -EACCES;
 413
 414         if (!bus->procdir) {
 415                 if (pci_proc_domain(bus)) {
 416                         sprintf(name, "%04x:%02x", pci_domain_nr(bus),
 417                                         bus->number);
 418                 } else {
 419                         sprintf(name, "%02x", bus->number);
 420                 }
 421                 bus->procdir = proc_mkdir(name, proc_bus_pci_dir);
 422                 if (!bus->procdir)
 423                         return -ENOMEM;
 424         }
 425
 426         sprintf(name, "%02x.%x", PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn));
 427         e = proc_create_data(name, S_IFREG | S_IRUGO | S_IWUSR, bus->procdir,
 428                              &proc_bus_pci_ops, dev);
 429         if (!e)
 430                 return -ENOMEM;
 431         proc_set_size(e, dev->cfg_size);
 432         dev->procent = e;
 433
 434         return 0;
 435 }
 436
 437 int pci_proc_detach_device(struct pci_dev *dev)
 438 {
 439         proc_remove(dev->procent);
 440         dev->procent = NULL;
 441         return 0;
 442 }
 443
 444 int pci_proc_detach_bus(struct pci_bus *bus)
 445 {
 446         proc_remove(bus->procdir);
 447         return 0;
 448 }
 449
 450 static int __init pci_proc_init(void)
 451 {
 452         struct pci_dev *dev = NULL;
 453         proc_bus_pci_dir = proc_mkdir("bus/pci", NULL);
 454         proc_create_seq("devices", 0, proc_bus_pci_dir,
 455                     &proc_bus_pci_devices_op);
 456         proc_initialized = 1;
 457         for_each_pci_dev(dev)
 458                 pci_proc_attach_device(dev);
 459
 460         return 0;
 461 }
 462 device_initcall(pci_proc_init);