drivers/pci/pci-sysfs.c

   1 /*
   2  * drivers/pci/pci-sysfs.c
   3  *
   4  * (C) Copyright 2002-2004 Greg Kroah-Hartman <greg@kroah.com>
   5  * (C) Copyright 2002-2004 IBM Corp.
   6  * (C) Copyright 2003 Matthew Wilcox
   7  * (C) Copyright 2003 Hewlett-Packard
   8  * (C) Copyright 2004 Jon Smirl <jonsmirl@yahoo.com>
   9  * (C) Copyright 2004 Silicon Graphics, Inc. Jesse Barnes <jbarnes@sgi.com>
  10  *
  11  * File attributes for PCI devices
  12  *
  13  * Modeled after usb's driverfs.c
  14  *
  15  */
  16
  17
  18 #include <linux/kernel.h>
  19 #include <linux/pci.h>
  20 #include <linux/stat.h>
  21 #include <linux/topology.h>
  22 #include <linux/mm.h>
  23
  24 #include "pci.h"
  25
  26 static int sysfs_initialized;   /* = 0 */
  27
  28 /* show configuration fields */
  29 #define pci_config_attr(field, format_string)                           \
  30 static ssize_t                                                          \
  31 field##_show(struct device *dev, struct device_attribute *attr, char *buf)                              \
  32 {                                                                       \
  33         struct pci_dev *pdev;                                           \
  34                                                                         \
  35         pdev = to_pci_dev (dev);                                        \
  36         return sprintf (buf, format_string, pdev->field);               \
  37 }
  38
  39 pci_config_attr(vendor, "0x%04x\n");
  40 pci_config_attr(device, "0x%04x\n");
  41 pci_config_attr(subsystem_vendor, "0x%04x\n");
  42 pci_config_attr(subsystem_device, "0x%04x\n");
  43 pci_config_attr(class, "0x%06x\n");
  44 pci_config_attr(irq, "%u\n");
  45 pci_config_attr(is_enabled, "%u\n");
  46
  47 static ssize_t broken_parity_status_show(struct device *dev,
  48                                          struct device_attribute *attr,
  49                                          char *buf)
  50 {
  51         struct pci_dev *pdev = to_pci_dev(dev);
  52         return sprintf (buf, "%u\n", pdev->broken_parity_status);
  53 }
  54
  55 static ssize_t broken_parity_status_store(struct device *dev,
  56                                           struct device_attribute *attr,
  57                                           const char *buf, size_t count)
  58 {
  59         struct pci_dev *pdev = to_pci_dev(dev);
  60         ssize_t consumed = -EINVAL;
  61
  62         if ((count > 0) && (*buf == '0' || *buf == '1')) {
  63                 pdev->broken_parity_status = *buf == '1' ? 1 : 0;
  64                 consumed = count;
  65         }
  66         return consumed;
  67 }
  68
  69 static ssize_t local_cpus_show(struct device *dev,
  70                         struct device_attribute *attr, char *buf)
  71 {
  72         cpumask_t mask;
  73         int len;
  74
  75         mask = pcibus_to_cpumask(to_pci_dev(dev)->bus);
  76         len = cpumask_scnprintf(buf, PAGE_SIZE-2, mask);
  77         strcat(buf,"\n");
  78         return 1+len;
  79 }
  80
  81 /* show resources */
  82 static ssize_t
  83 resource_show(struct device * dev, struct device_attribute *attr, char * buf)
  84 {
  85         struct pci_dev * pci_dev = to_pci_dev(dev);
  86         char * str = buf;
  87         int i;
  88         int max = 7;
  89         resource_size_t start, end;
  90
  91         if (pci_dev->subordinate)
  92                 max = DEVICE_COUNT_RESOURCE;
  93
  94         for (i = 0; i < max; i++) {
  95                 struct resource *res =  &pci_dev->resource[i];
  96                 pci_resource_to_user(pci_dev, i, res, &start, &end);
  97                 str += sprintf(str,"0x%016llx 0x%016llx 0x%016llx\n",
  98                                (unsigned long long)start,
  99                                (unsigned long long)end,
 100                                (unsigned long long)res->flags);
 101         }
 102         return (str - buf);
 103 }
 104
 105 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
 106 {
 107         struct pci_dev *pci_dev = to_pci_dev(dev);
 108
 109         return sprintf(buf, "pci:v%08Xd%08Xsv%08Xsd%08Xbc%02Xsc%02Xi%02x\n",
 110                        pci_dev->vendor, pci_dev->device,
 111                        pci_dev->subsystem_vendor, pci_dev->subsystem_device,
 112                        (u8)(pci_dev->class >> 16), (u8)(pci_dev->class >> 8),
 113                        (u8)(pci_dev->class));
 114 }
 115 static ssize_t
 116 is_enabled_store(struct device *dev, struct device_attribute *attr,
 117                 const char *buf, size_t count)
 118 {
 119         struct pci_dev *pdev = to_pci_dev(dev);
 120
 121         /* this can crash the machine when done on the "wrong" device */
 122         if (!capable(CAP_SYS_ADMIN))
 123                 return count;
 124
 125         if (*buf == '0')
 126                 pci_disable_device(pdev);
 127
 128         if (*buf == '1')
 129                 pci_enable_device(pdev);
 130
 131         return count;
 132 }
 133
 134 static ssize_t
 135 msi_bus_show(struct device *dev, struct device_attribute *attr, char *buf)
 136 {
 137         struct pci_dev *pdev = to_pci_dev(dev);
 138
 139         if (!pdev->subordinate)
 140                 return 0;
 141
 142         return sprintf (buf, "%u\n",
 143                         !(pdev->subordinate->bus_flags & PCI_BUS_FLAGS_NO_MSI));
 144 }
 145
 146 static ssize_t
 147 msi_bus_store(struct device *dev, struct device_attribute *attr,
 148               const char *buf, size_t count)
 149 {
 150         struct pci_dev *pdev = to_pci_dev(dev);
 151
 152         /* bad things may happen if the no_msi flag is changed
 153          * while some drivers are loaded */
 154         if (!capable(CAP_SYS_ADMIN))
 155                 return count;
 156
 157         if (!pdev->subordinate)
 158                 return count;
 159
 160         if (*buf == '0') {
 161                 pdev->subordinate->bus_flags |= PCI_BUS_FLAGS_NO_MSI;
 162                 dev_warn(&pdev->dev, "forced subordinate bus to not support MSI,"
 163                          " bad things could happen.\n");
 164         }
 165
 166         if (*buf == '1') {
 167                 pdev->subordinate->bus_flags &= ~PCI_BUS_FLAGS_NO_MSI;
 168                 dev_warn(&pdev->dev, "forced subordinate bus to support MSI,"
 169                          " bad things could happen.\n");
 170         }
 171
 172         return count;
 173 }
 174
 175 struct device_attribute pci_dev_attrs[] = {
 176         __ATTR_RO(resource),
 177         __ATTR_RO(vendor),
 178         __ATTR_RO(device),
 179         __ATTR_RO(subsystem_vendor),
 180         __ATTR_RO(subsystem_device),
 181         __ATTR_RO(class),
 182         __ATTR_RO(irq),
 183         __ATTR_RO(local_cpus),
 184         __ATTR_RO(modalias),
 185         __ATTR(enable, 0600, is_enabled_show, is_enabled_store),
 186         __ATTR(broken_parity_status,(S_IRUGO|S_IWUSR),
 187                 broken_parity_status_show,broken_parity_status_store),
 188         __ATTR(msi_bus, 0644, msi_bus_show, msi_bus_store),
 189         __ATTR_NULL,
 190 };
 191
 192 static ssize_t
 193 pci_read_config(struct kobject *kobj, char *buf, loff_t off, size_t count)
 194 {
 195         struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj));
 196         unsigned int size = 64;
 197         loff_t init_off = off;
 198         u8 *data = (u8*) buf;
 199
 200         /* Several chips lock up trying to read undefined config space */
 201         if (capable(CAP_SYS_ADMIN)) {
 202                 size = dev->cfg_size;
 203         } else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) {
 204                 size = 128;
 205         }
 206
 207         if (off > size)
 208                 return 0;
 209         if (off + count > size) {
 210                 size -= off;
 211                 count = size;
 212         } else {
 213                 size = count;
 214         }
 215
 216         if ((off & 1) && size) {
 217                 u8 val;
 218                 pci_user_read_config_byte(dev, off, &val);
 219                 data[off - init_off] = val;
 220                 off++;
 221                 size--;
 222         }
 223
 224         if ((off & 3) && size > 2) {
 225                 u16 val;
 226                 pci_user_read_config_word(dev, off, &val);
 227                 data[off - init_off] = val & 0xff;
 228                 data[off - init_off + 1] = (val >> 8) & 0xff;
 229                 off += 2;
 230                 size -= 2;
 231         }
 232
 233         while (size > 3) {
 234                 u32 val;
 235                 pci_user_read_config_dword(dev, off, &val);
 236                 data[off - init_off] = val & 0xff;
 237                 data[off - init_off + 1] = (val >> 8) & 0xff;
 238                 data[off - init_off + 2] = (val >> 16) & 0xff;
 239                 data[off - init_off + 3] = (val >> 24) & 0xff;
 240                 off += 4;
 241                 size -= 4;
 242         }
 243
 244         if (size >= 2) {
 245                 u16 val;
 246                 pci_user_read_config_word(dev, off, &val);
 247                 data[off - init_off] = val & 0xff;
 248                 data[off - init_off + 1] = (val >> 8) & 0xff;
 249                 off += 2;
 250                 size -= 2;
 251         }
 252
 253         if (size > 0) {
 254                 u8 val;
 255                 pci_user_read_config_byte(dev, off, &val);
 256                 data[off - init_off] = val;
 257                 off++;
 258                 --size;
 259         }
 260
 261         return count;
 262 }
 263
 264 static ssize_t
 265 pci_write_config(struct kobject *kobj, char *buf, loff_t off, size_t count)
 266 {
 267         struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj));
 268         unsigned int size = count;
 269         loff_t init_off = off;
 270         u8 *data = (u8*) buf;
 271
 272         if (off > dev->cfg_size)
 273                 return 0;
 274         if (off + count > dev->cfg_size) {
 275                 size = dev->cfg_size - off;
 276                 count = size;
 277         }
 278
 279         if ((off & 1) && size) {
 280                 pci_user_write_config_byte(dev, off, data[off - init_off]);
 281                 off++;
 282                 size--;
 283         }
 284
 285         if ((off & 3) && size > 2) {
 286                 u16 val = data[off - init_off];
 287                 val |= (u16) data[off - init_off + 1] << 8;
 288                 pci_user_write_config_word(dev, off, val);
 289                 off += 2;
 290                 size -= 2;
 291         }
 292
 293         while (size > 3) {
 294                 u32 val = data[off - init_off];
 295                 val |= (u32) data[off - init_off + 1] << 8;
 296                 val |= (u32) data[off - init_off + 2] << 16;
 297                 val |= (u32) data[off - init_off + 3] << 24;
 298                 pci_user_write_config_dword(dev, off, val);
 299                 off += 4;
 300                 size -= 4;
 301         }
 302
 303         if (size >= 2) {
 304                 u16 val = data[off - init_off];
 305                 val |= (u16) data[off - init_off + 1] << 8;
 306                 pci_user_write_config_word(dev, off, val);
 307                 off += 2;
 308                 size -= 2;
 309         }
 310
 311         if (size) {
 312                 pci_user_write_config_byte(dev, off, data[off - init_off]);
 313                 off++;
 314                 --size;
 315         }
 316
 317         return count;
 318 }
 319
 320 #ifdef HAVE_PCI_LEGACY
 321 /**
 322  * pci_read_legacy_io - read byte(s) from legacy I/O port space
 323  * @kobj: kobject corresponding to file to read from
 324  * @buf: buffer to store results
 325  * @off: offset into legacy I/O port space
 326  * @count: number of bytes to read
 327  *
 328  * Reads 1, 2, or 4 bytes from legacy I/O port space using an arch specific
 329  * callback routine (pci_legacy_read).
 330  */
 331 ssize_t
 332 pci_read_legacy_io(struct kobject *kobj, char *buf, loff_t off, size_t count)
 333 {
 334         struct pci_bus *bus = to_pci_bus(container_of(kobj,
 335                                                       struct class_device,
 336                                                       kobj));
 337
 338         /* Only support 1, 2 or 4 byte accesses */
 339         if (count != 1 && count != 2 && count != 4)
 340                 return -EINVAL;
 341
 342         return pci_legacy_read(bus, off, (u32 *)buf, count);
 343 }
 344
 345 /**
 346  * pci_write_legacy_io - write byte(s) to legacy I/O port space
 347  * @kobj: kobject corresponding to file to read from
 348  * @buf: buffer containing value to be written
 349  * @off: offset into legacy I/O port space
 350  * @count: number of bytes to write
 351  *
 352  * Writes 1, 2, or 4 bytes from legacy I/O port space using an arch specific
 353  * callback routine (pci_legacy_write).
 354  */
 355 ssize_t
 356 pci_write_legacy_io(struct kobject *kobj, char *buf, loff_t off, size_t count)
 357 {
 358         struct pci_bus *bus = to_pci_bus(container_of(kobj,
 359                                                       struct class_device,
 360                                                       kobj));
 361         /* Only support 1, 2 or 4 byte accesses */
 362         if (count != 1 && count != 2 && count != 4)
 363                 return -EINVAL;
 364
 365         return pci_legacy_write(bus, off, *(u32 *)buf, count);
 366 }
 367
 368 /**
 369  * pci_mmap_legacy_mem - map legacy PCI memory into user memory space
 370  * @kobj: kobject corresponding to device to be mapped
 371  * @attr: struct bin_attribute for this file
 372  * @vma: struct vm_area_struct passed to mmap
 373  *
 374  * Uses an arch specific callback, pci_mmap_legacy_page_range, to mmap
 375  * legacy memory space (first meg of bus space) into application virtual
 376  * memory space.
 377  */
 378 int
 379 pci_mmap_legacy_mem(struct kobject *kobj, struct bin_attribute *attr,
 380                     struct vm_area_struct *vma)
 381 {
 382         struct pci_bus *bus = to_pci_bus(container_of(kobj,
 383                                                       struct class_device,
 384                                                       kobj));
 385
 386         return pci_mmap_legacy_page_range(bus, vma);
 387 }
 388 #endif /* HAVE_PCI_LEGACY */
 389
 390 #ifdef HAVE_PCI_MMAP
 391 /**
 392  * pci_mmap_resource - map a PCI resource into user memory space
 393  * @kobj: kobject for mapping
 394  * @attr: struct bin_attribute for the file being mapped
 395  * @vma: struct vm_area_struct passed into the mmap
 396  *
 397  * Use the regular PCI mapping routines to map a PCI resource into userspace.
 398  * FIXME: write combining?  maybe automatic for prefetchable regions?
 399  */
 400 static int
 401 pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,
 402                   struct vm_area_struct *vma)
 403 {
 404         struct pci_dev *pdev = to_pci_dev(container_of(kobj,
 405                                                        struct device, kobj));
 406         struct resource *res = (struct resource *)attr->private;
 407         enum pci_mmap_state mmap_type;
 408         resource_size_t start, end;
 409         int i;
 410
 411         for (i = 0; i < PCI_ROM_RESOURCE; i++)
 412                 if (res == &pdev->resource[i])
 413                         break;
 414         if (i >= PCI_ROM_RESOURCE)
 415                 return -ENODEV;
 416
 417         /* pci_mmap_page_range() expects the same kind of entry as coming
 418          * from /proc/bus/pci/ which is a "user visible" value. If this is
 419          * different from the resource itself, arch will do necessary fixup.
 420          */
 421         pci_resource_to_user(pdev, i, res, &start, &end);
 422         vma->vm_pgoff += start >> PAGE_SHIFT;
 423         mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io;
 424
 425         return pci_mmap_page_range(pdev, vma, mmap_type, 0);
 426 }
 427
 428 /**
 429  * pci_create_resource_files - create resource files in sysfs for @dev
 430  * @dev: dev in question
 431  *
 432  * Walk the resources in @dev creating files for each resource available.
 433  */
 434 static void
 435 pci_create_resource_files(struct pci_dev *pdev)
 436 {
 437         int i;
 438
 439         /* Expose the PCI resources from this device as files */
 440         for (i = 0; i < PCI_ROM_RESOURCE; i++) {
 441                 struct bin_attribute *res_attr;
 442
 443                 /* skip empty resources */
 444                 if (!pci_resource_len(pdev, i))
 445                         continue;
 446
 447                 /* allocate attribute structure, piggyback attribute name */
 448                 res_attr = kzalloc(sizeof(*res_attr) + 10, GFP_ATOMIC);
 449                 if (res_attr) {
 450                         char *res_attr_name = (char *)(res_attr + 1);
 451
 452                         pdev->res_attr[i] = res_attr;
 453                         sprintf(res_attr_name, "resource%d", i);
 454                         res_attr->attr.name = res_attr_name;
 455                         res_attr->attr.mode = S_IRUSR | S_IWUSR;
 456                         res_attr->attr.owner = THIS_MODULE;
 457                         res_attr->size = pci_resource_len(pdev, i);
 458                         res_attr->mmap = pci_mmap_resource;
 459                         res_attr->private = &pdev->resource[i];
 460                         sysfs_create_bin_file(&pdev->dev.kobj, res_attr);
 461                 }
 462         }
 463 }
 464
 465 /**
 466  * pci_remove_resource_files - cleanup resource files
 467  * @dev: dev to cleanup
 468  *
 469  * If we created resource files for @dev, remove them from sysfs and
 470  * free their resources.
 471  */
 472 static void
 473 pci_remove_resource_files(struct pci_dev *pdev)
 474 {
 475         int i;
 476
 477         for (i = 0; i < PCI_ROM_RESOURCE; i++) {
 478                 struct bin_attribute *res_attr;
 479
 480                 res_attr = pdev->res_attr[i];
 481                 if (res_attr) {
 482                         sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
 483                         kfree(res_attr);
 484                 }
 485         }
 486 }
 487 #else /* !HAVE_PCI_MMAP */
 488 static inline void pci_create_resource_files(struct pci_dev *dev) { return; }
 489 static inline void pci_remove_resource_files(struct pci_dev *dev) { return; }
 490 #endif /* HAVE_PCI_MMAP */
 491
 492 /**
 493  * pci_write_rom - used to enable access to the PCI ROM display
 494  * @kobj: kernel object handle
 495  * @buf: user input
 496  * @off: file offset
 497  * @count: number of byte in input
 498  *
 499  * writing anything except 0 enables it
 500  */
 501 static ssize_t
 502 pci_write_rom(struct kobject *kobj, char *buf, loff_t off, size_t count)
 503 {
 504         struct pci_dev *pdev = to_pci_dev(container_of(kobj, struct device, kobj));
 505
 506         if ((off ==  0) && (*buf == '0') && (count == 2))
 507                 pdev->rom_attr_enabled = 0;
 508         else
 509                 pdev->rom_attr_enabled = 1;
 510
 511         return count;
 512 }
 513
 514 /**
 515  * pci_read_rom - read a PCI ROM
 516  * @kobj: kernel object handle
 517  * @buf: where to put the data we read from the ROM
 518  * @off: file offset
 519  * @count: number of bytes to read
 520  *
 521  * Put @count bytes starting at @off into @buf from the ROM in the PCI
 522  * device corresponding to @kobj.
 523  */
 524 static ssize_t
 525 pci_read_rom(struct kobject *kobj, char *buf, loff_t off, size_t count)
 526 {
 527         struct pci_dev *pdev = to_pci_dev(container_of(kobj, struct device, kobj));
 528         void __iomem *rom;
 529         size_t size;
 530
 531         if (!pdev->rom_attr_enabled)
 532                 return -EINVAL;
 533
 534         rom = pci_map_rom(pdev, &size); /* size starts out as PCI window size */
 535         if (!rom)
 536                 return 0;
 537
 538         if (off >= size)
 539                 count = 0;
 540         else {
 541                 if (off + count > size)
 542                         count = size - off;
 543
 544                 memcpy_fromio(buf, rom + off, count);
 545         }
 546         pci_unmap_rom(pdev, rom);
 547
 548         return count;
 549 }
 550
 551 static struct bin_attribute pci_config_attr = {
 552         .attr = {
 553                 .name = "config",
 554                 .mode = S_IRUGO | S_IWUSR,
 555                 .owner = THIS_MODULE,
 556         },
 557         .size = 256,
 558         .read = pci_read_config,
 559         .write = pci_write_config,
 560 };
 561
 562 static struct bin_attribute pcie_config_attr = {
 563         .attr = {
 564                 .name = "config",
 565                 .mode = S_IRUGO | S_IWUSR,
 566                 .owner = THIS_MODULE,
 567         },
 568         .size = 4096,
 569         .read = pci_read_config,
 570         .write = pci_write_config,
 571 };
 572
 573 int pci_create_sysfs_dev_files (struct pci_dev *pdev)
 574 {
 575         if (!sysfs_initialized)
 576                 return -EACCES;
 577
 578         if (pdev->cfg_size < 4096)
 579                 sysfs_create_bin_file(&pdev->dev.kobj, &pci_config_attr);
 580         else
 581                 sysfs_create_bin_file(&pdev->dev.kobj, &pcie_config_attr);
 582
 583         pci_create_resource_files(pdev);
 584
 585         /* If the device has a ROM, try to expose it in sysfs. */
 586         if (pci_resource_len(pdev, PCI_ROM_RESOURCE)) {
 587                 struct bin_attribute *rom_attr;
 588
 589                 rom_attr = kzalloc(sizeof(*rom_attr), GFP_ATOMIC);
 590                 if (rom_attr) {
 591                         pdev->rom_attr = rom_attr;
 592                         rom_attr->size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
 593                         rom_attr->attr.name = "rom";
 594                         rom_attr->attr.mode = S_IRUSR;
 595                         rom_attr->attr.owner = THIS_MODULE;
 596                         rom_attr->read = pci_read_rom;
 597                         rom_attr->write = pci_write_rom;
 598                         sysfs_create_bin_file(&pdev->dev.kobj, rom_attr);
 599                 }
 600         }
 601         /* add platform-specific attributes */
 602         pcibios_add_platform_entries(pdev);
 603
 604         return 0;
 605 }
 606
 607 /**
 608  * pci_remove_sysfs_dev_files - cleanup PCI specific sysfs files
 609  * @pdev: device whose entries we should free
 610  *
 611  * Cleanup when @pdev is removed from sysfs.
 612  */
 613 void pci_remove_sysfs_dev_files(struct pci_dev *pdev)
 614 {
 615         if (pdev->cfg_size < 4096)
 616                 sysfs_remove_bin_file(&pdev->dev.kobj, &pci_config_attr);
 617         else
 618                 sysfs_remove_bin_file(&pdev->dev.kobj, &pcie_config_attr);
 619
 620         pci_remove_resource_files(pdev);
 621
 622         if (pci_resource_len(pdev, PCI_ROM_RESOURCE)) {
 623                 if (pdev->rom_attr) {
 624                         sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr);
 625                         kfree(pdev->rom_attr);
 626                 }
 627         }
 628 }
 629
 630 static int __init pci_sysfs_init(void)
 631 {
 632         struct pci_dev *pdev = NULL;
 633
 634         sysfs_initialized = 1;
 635         for_each_pci_dev(pdev)
 636                 pci_create_sysfs_dev_files(pdev);
 637
 638         return 0;
 639 }
 640
 641 __initcall(pci_sysfs_init);