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