drivers/pci/of.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * PCI <-> OF mapping helpers
   4  *
   5  * Copyright 2011 IBM Corp.
   6  */
   7 #define pr_fmt(fmt)     "PCI: OF: " fmt
   8
   9 #include <linux/irqdomain.h>
  10 #include <linux/kernel.h>
  11 #include <linux/pci.h>
  12 #include <linux/of.h>
  13 #include <linux/of_irq.h>
  14 #include <linux/of_address.h>
  15 #include <linux/of_pci.h>
  16 #include "pci.h"
  17
  18 #ifdef CONFIG_PCI
  19 void pci_set_of_node(struct pci_dev *dev)
  20 {
  21         if (!dev->bus->dev.of_node)
  22                 return;
  23         dev->dev.of_node = of_pci_find_child_device(dev->bus->dev.of_node,
  24                                                     dev->devfn);
  25         if (dev->dev.of_node)
  26                 dev->dev.fwnode = &dev->dev.of_node->fwnode;
  27 }
  28
  29 void pci_release_of_node(struct pci_dev *dev)
  30 {
  31         of_node_put(dev->dev.of_node);
  32         dev->dev.of_node = NULL;
  33         dev->dev.fwnode = NULL;
  34 }
  35
  36 void pci_set_bus_of_node(struct pci_bus *bus)
  37 {
  38         struct device_node *node;
  39
  40         if (bus->self == NULL) {
  41                 node = pcibios_get_phb_of_node(bus);
  42         } else {
  43                 node = of_node_get(bus->self->dev.of_node);
  44                 if (node && of_property_read_bool(node, "external-facing"))
  45                         bus->self->untrusted = true;
  46         }
  47
  48         bus->dev.of_node = node;
  49
  50         if (bus->dev.of_node)
  51                 bus->dev.fwnode = &bus->dev.of_node->fwnode;
  52 }
  53
  54 void pci_release_bus_of_node(struct pci_bus *bus)
  55 {
  56         of_node_put(bus->dev.of_node);
  57         bus->dev.of_node = NULL;
  58         bus->dev.fwnode = NULL;
  59 }
  60
  61 struct device_node * __weak pcibios_get_phb_of_node(struct pci_bus *bus)
  62 {
  63         /* This should only be called for PHBs */
  64         if (WARN_ON(bus->self || bus->parent))
  65                 return NULL;
  66
  67         /*
  68          * Look for a node pointer in either the intermediary device we
  69          * create above the root bus or its own parent. Normally only
  70          * the later is populated.
  71          */
  72         if (bus->bridge->of_node)
  73                 return of_node_get(bus->bridge->of_node);
  74         if (bus->bridge->parent && bus->bridge->parent->of_node)
  75                 return of_node_get(bus->bridge->parent->of_node);
  76         return NULL;
  77 }
  78
  79 struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus)
  80 {
  81 #ifdef CONFIG_IRQ_DOMAIN
  82         struct irq_domain *d;
  83
  84         if (!bus->dev.of_node)
  85                 return NULL;
  86
  87         /* Start looking for a phandle to an MSI controller. */
  88         d = of_msi_get_domain(&bus->dev, bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
  89         if (d)
  90                 return d;
  91
  92         /*
  93          * If we don't have an msi-parent property, look for a domain
  94          * directly attached to the host bridge.
  95          */
  96         d = irq_find_matching_host(bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
  97         if (d)
  98                 return d;
  99
 100         return irq_find_host(bus->dev.of_node);
 101 #else
 102         return NULL;
 103 #endif
 104 }
 105
 106 static inline int __of_pci_pci_compare(struct device_node *node,
 107                                        unsigned int data)
 108 {
 109         int devfn;
 110
 111         devfn = of_pci_get_devfn(node);
 112         if (devfn < 0)
 113                 return 0;
 114
 115         return devfn == data;
 116 }
 117
 118 struct device_node *of_pci_find_child_device(struct device_node *parent,
 119                                              unsigned int devfn)
 120 {
 121         struct device_node *node, *node2;
 122
 123         for_each_child_of_node(parent, node) {
 124                 if (__of_pci_pci_compare(node, devfn))
 125                         return node;
 126                 /*
 127                  * Some OFs create a parent node "multifunc-device" as
 128                  * a fake root for all functions of a multi-function
 129                  * device we go down them as well.
 130                  */
 131                 if (of_node_name_eq(node, "multifunc-device")) {
 132                         for_each_child_of_node(node, node2) {
 133                                 if (__of_pci_pci_compare(node2, devfn)) {
 134                                         of_node_put(node);
 135                                         return node2;
 136                                 }
 137                         }
 138                 }
 139         }
 140         return NULL;
 141 }
 142 EXPORT_SYMBOL_GPL(of_pci_find_child_device);
 143
 144 /**
 145  * of_pci_get_devfn() - Get device and function numbers for a device node
 146  * @np: device node
 147  *
 148  * Parses a standard 5-cell PCI resource and returns an 8-bit value that can
 149  * be passed to the PCI_SLOT() and PCI_FUNC() macros to extract the device
 150  * and function numbers respectively. On error a negative error code is
 151  * returned.
 152  */
 153 int of_pci_get_devfn(struct device_node *np)
 154 {
 155         u32 reg[5];
 156         int error;
 157
 158         error = of_property_read_u32_array(np, "reg", reg, ARRAY_SIZE(reg));
 159         if (error)
 160                 return error;
 161
 162         return (reg[0] >> 8) & 0xff;
 163 }
 164 EXPORT_SYMBOL_GPL(of_pci_get_devfn);
 165
 166 /**
 167  * of_pci_parse_bus_range() - parse the bus-range property of a PCI device
 168  * @node: device node
 169  * @res: address to a struct resource to return the bus-range
 170  *
 171  * Returns 0 on success or a negative error-code on failure.
 172  */
 173 int of_pci_parse_bus_range(struct device_node *node, struct resource *res)
 174 {
 175         u32 bus_range[2];
 176         int error;
 177
 178         error = of_property_read_u32_array(node, "bus-range", bus_range,
 179                                            ARRAY_SIZE(bus_range));
 180         if (error)
 181                 return error;
 182
 183         res->name = node->name;
 184         res->start = bus_range[0];
 185         res->end = bus_range[1];
 186         res->flags = IORESOURCE_BUS;
 187
 188         return 0;
 189 }
 190 EXPORT_SYMBOL_GPL(of_pci_parse_bus_range);
 191
 192 /**
 193  * This function will try to obtain the host bridge domain number by
 194  * finding a property called "linux,pci-domain" of the given device node.
 195  *
 196  * @node: device tree node with the domain information
 197  *
 198  * Returns the associated domain number from DT in the range [0-0xffff], or
 199  * a negative value if the required property is not found.
 200  */
 201 int of_get_pci_domain_nr(struct device_node *node)
 202 {
 203         u32 domain;
 204         int error;
 205
 206         error = of_property_read_u32(node, "linux,pci-domain", &domain);
 207         if (error)
 208                 return error;
 209
 210         return (u16)domain;
 211 }
 212 EXPORT_SYMBOL_GPL(of_get_pci_domain_nr);
 213
 214 /**
 215  * of_pci_check_probe_only - Setup probe only mode if linux,pci-probe-only
 216  *                           is present and valid
 217  */
 218 void of_pci_check_probe_only(void)
 219 {
 220         u32 val;
 221         int ret;
 222
 223         ret = of_property_read_u32(of_chosen, "linux,pci-probe-only", &val);
 224         if (ret) {
 225                 if (ret == -ENODATA || ret == -EOVERFLOW)
 226                         pr_warn("linux,pci-probe-only without valid value, ignoring\n");
 227                 return;
 228         }
 229
 230         if (val)
 231                 pci_add_flags(PCI_PROBE_ONLY);
 232         else
 233                 pci_clear_flags(PCI_PROBE_ONLY);
 234
 235         pr_info("PROBE_ONLY %sabled\n", val ? "en" : "dis");
 236 }
 237 EXPORT_SYMBOL_GPL(of_pci_check_probe_only);
 238
 239 /**
 240  * devm_of_pci_get_host_bridge_resources() - Resource-managed parsing of PCI
 241  *                                           host bridge resources from DT
 242  * @dev: host bridge device
 243  * @busno: bus number associated with the bridge root bus
 244  * @bus_max: maximum number of buses for this bridge
 245  * @resources: list where the range of resources will be added after DT parsing
 246  * @io_base: pointer to a variable that will contain on return the physical
 247  * address for the start of the I/O range. Can be NULL if the caller doesn't
 248  * expect I/O ranges to be present in the device tree.
 249  *
 250  * This function will parse the "ranges" property of a PCI host bridge device
 251  * node and setup the resource mapping based on its content. It is expected
 252  * that the property conforms with the Power ePAPR document.
 253  *
 254  * It returns zero if the range parsing has been successful or a standard error
 255  * value if it failed.
 256  */
 257 static int devm_of_pci_get_host_bridge_resources(struct device *dev,
 258                         unsigned char busno, unsigned char bus_max,
 259                         struct list_head *resources,
 260                         struct list_head *ib_resources,
 261                         resource_size_t *io_base)
 262 {
 263         struct device_node *dev_node = dev->of_node;
 264         struct resource *res, tmp_res;
 265         struct resource *bus_range;
 266         struct of_pci_range range;
 267         struct of_pci_range_parser parser;
 268         const char *range_type;
 269         int err;
 270
 271         if (io_base)
 272                 *io_base = (resource_size_t)OF_BAD_ADDR;
 273
 274         bus_range = devm_kzalloc(dev, sizeof(*bus_range), GFP_KERNEL);
 275         if (!bus_range)
 276                 return -ENOMEM;
 277
 278         dev_info(dev, "host bridge %pOF ranges:\n", dev_node);
 279
 280         err = of_pci_parse_bus_range(dev_node, bus_range);
 281         if (err) {
 282                 bus_range->start = busno;
 283                 bus_range->end = bus_max;
 284                 bus_range->flags = IORESOURCE_BUS;
 285                 dev_info(dev, "  No bus range found for %pOF, using %pR\n",
 286                          dev_node, bus_range);
 287         } else {
 288                 if (bus_range->end > bus_range->start + bus_max)
 289                         bus_range->end = bus_range->start + bus_max;
 290         }
 291         pci_add_resource(resources, bus_range);
 292
 293         /* Check for ranges property */
 294         err = of_pci_range_parser_init(&parser, dev_node);
 295         if (err)
 296                 goto failed;
 297
 298         dev_dbg(dev, "Parsing ranges property...\n");
 299         for_each_of_pci_range(&parser, &range) {
 300                 /* Read next ranges element */
 301                 if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO)
 302                         range_type = "IO";
 303                 else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM)
 304                         range_type = "MEM";
 305                 else
 306                         range_type = "err";
 307                 dev_info(dev, "  %6s %#012llx..%#012llx -> %#012llx\n",
 308                          range_type, range.cpu_addr,
 309                          range.cpu_addr + range.size - 1, range.pci_addr);
 310
 311                 /*
 312                  * If we failed translation or got a zero-sized region
 313                  * then skip this range
 314                  */
 315                 if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
 316                         continue;
 317
 318                 err = of_pci_range_to_resource(&range, dev_node, &tmp_res);
 319                 if (err)
 320                         continue;
 321
 322                 res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL);
 323                 if (!res) {
 324                         err = -ENOMEM;
 325                         goto failed;
 326                 }
 327
 328                 if (resource_type(res) == IORESOURCE_IO) {
 329                         if (!io_base) {
 330                                 dev_err(dev, "I/O range found for %pOF. Please provide an io_base pointer to save CPU base address\n",
 331                                         dev_node);
 332                                 err = -EINVAL;
 333                                 goto failed;
 334                         }
 335                         if (*io_base != (resource_size_t)OF_BAD_ADDR)
 336                                 dev_warn(dev, "More than one I/O resource converted for %pOF. CPU base address for old range lost!\n",
 337                                          dev_node);
 338                         *io_base = range.cpu_addr;
 339                 }
 340
 341                 pci_add_resource_offset(resources, res, res->start - range.pci_addr);
 342         }
 343
 344         /* Check for dma-ranges property */
 345         if (!ib_resources)
 346                 return 0;
 347         err = of_pci_dma_range_parser_init(&parser, dev_node);
 348         if (err)
 349                 return 0;
 350
 351         dev_dbg(dev, "Parsing dma-ranges property...\n");
 352         for_each_of_pci_range(&parser, &range) {
 353                 struct resource_entry *entry;
 354                 /*
 355                  * If we failed translation or got a zero-sized region
 356                  * then skip this range
 357                  */
 358                 if (((range.flags & IORESOURCE_TYPE_BITS) != IORESOURCE_MEM) ||
 359                     range.cpu_addr == OF_BAD_ADDR || range.size == 0)
 360                         continue;
 361
 362                 dev_info(dev, "  %6s %#012llx..%#012llx -> %#012llx\n",
 363                          "IB MEM", range.cpu_addr,
 364                          range.cpu_addr + range.size - 1, range.pci_addr);
 365
 366
 367                 err = of_pci_range_to_resource(&range, dev_node, &tmp_res);
 368                 if (err)
 369                         continue;
 370
 371                 res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL);
 372                 if (!res) {
 373                         err = -ENOMEM;
 374                         goto failed;
 375                 }
 376
 377                 /* Keep the resource list sorted */
 378                 resource_list_for_each_entry(entry, ib_resources)
 379                         if (entry->res->start > res->start)
 380                                 break;
 381
 382                 pci_add_resource_offset(&entry->node, res,
 383                                         res->start - range.pci_addr);
 384         }
 385
 386         return 0;
 387
 388 failed:
 389         pci_free_resource_list(resources);
 390         return err;
 391 }
 392
 393 #if IS_ENABLED(CONFIG_OF_IRQ)
 394 /**
 395  * of_irq_parse_pci - Resolve the interrupt for a PCI device
 396  * @pdev:       the device whose interrupt is to be resolved
 397  * @out_irq:    structure of_phandle_args filled by this function
 398  *
 399  * This function resolves the PCI interrupt for a given PCI device. If a
 400  * device-node exists for a given pci_dev, it will use normal OF tree
 401  * walking. If not, it will implement standard swizzling and walk up the
 402  * PCI tree until an device-node is found, at which point it will finish
 403  * resolving using the OF tree walking.
 404  */
 405 static int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq)
 406 {
 407         struct device_node *dn, *ppnode;
 408         struct pci_dev *ppdev;
 409         __be32 laddr[3];
 410         u8 pin;
 411         int rc;
 412
 413         /*
 414          * Check if we have a device node, if yes, fallback to standard
 415          * device tree parsing
 416          */
 417         dn = pci_device_to_OF_node(pdev);
 418         if (dn) {
 419                 rc = of_irq_parse_one(dn, 0, out_irq);
 420                 if (!rc)
 421                         return rc;
 422         }
 423
 424         /*
 425          * Ok, we don't, time to have fun. Let's start by building up an
 426          * interrupt spec.  we assume #interrupt-cells is 1, which is standard
 427          * for PCI. If you do different, then don't use that routine.
 428          */
 429         rc = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin);
 430         if (rc != 0)
 431                 goto err;
 432         /* No pin, exit with no error message. */
 433         if (pin == 0)
 434                 return -ENODEV;
 435
 436         /* Now we walk up the PCI tree */
 437         for (;;) {
 438                 /* Get the pci_dev of our parent */
 439                 ppdev = pdev->bus->self;
 440
 441                 /* Ouch, it's a host bridge... */
 442                 if (ppdev == NULL) {
 443                         ppnode = pci_bus_to_OF_node(pdev->bus);
 444
 445                         /* No node for host bridge ? give up */
 446                         if (ppnode == NULL) {
 447                                 rc = -EINVAL;
 448                                 goto err;
 449                         }
 450                 } else {
 451                         /* We found a P2P bridge, check if it has a node */
 452                         ppnode = pci_device_to_OF_node(ppdev);
 453                 }
 454
 455                 /*
 456                  * Ok, we have found a parent with a device-node, hand over to
 457                  * the OF parsing code.
 458                  * We build a unit address from the linux device to be used for
 459                  * resolution. Note that we use the linux bus number which may
 460                  * not match your firmware bus numbering.
 461                  * Fortunately, in most cases, interrupt-map-mask doesn't
 462                  * include the bus number as part of the matching.
 463                  * You should still be careful about that though if you intend
 464                  * to rely on this function (you ship a firmware that doesn't
 465                  * create device nodes for all PCI devices).
 466                  */
 467                 if (ppnode)
 468                         break;
 469
 470                 /*
 471                  * We can only get here if we hit a P2P bridge with no node;
 472                  * let's do standard swizzling and try again
 473                  */
 474                 pin = pci_swizzle_interrupt_pin(pdev, pin);
 475                 pdev = ppdev;
 476         }
 477
 478         out_irq->np = ppnode;
 479         out_irq->args_count = 1;
 480         out_irq->args[0] = pin;
 481         laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8));
 482         laddr[1] = laddr[2] = cpu_to_be32(0);
 483         rc = of_irq_parse_raw(laddr, out_irq);
 484         if (rc)
 485                 goto err;
 486         return 0;
 487 err:
 488         if (rc == -ENOENT) {
 489                 dev_warn(&pdev->dev,
 490                         "%s: no interrupt-map found, INTx interrupts not available\n",
 491                         __func__);
 492                 pr_warn_once("%s: possibly some PCI slots don't have level triggered interrupts capability\n",
 493                         __func__);
 494         } else {
 495                 dev_err(&pdev->dev, "%s: failed with rc=%d\n", __func__, rc);
 496         }
 497         return rc;
 498 }
 499
 500 /**
 501  * of_irq_parse_and_map_pci() - Decode a PCI IRQ from the device tree and map to a VIRQ
 502  * @dev: The PCI device needing an IRQ
 503  * @slot: PCI slot number; passed when used as map_irq callback. Unused
 504  * @pin: PCI IRQ pin number; passed when used as map_irq callback. Unused
 505  *
 506  * @slot and @pin are unused, but included in the function so that this
 507  * function can be used directly as the map_irq callback to
 508  * pci_assign_irq() and struct pci_host_bridge.map_irq pointer
 509  */
 510 int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin)
 511 {
 512         struct of_phandle_args oirq;
 513         int ret;
 514
 515         ret = of_irq_parse_pci(dev, &oirq);
 516         if (ret)
 517                 return 0; /* Proper return code 0 == NO_IRQ */
 518
 519         return irq_create_of_mapping(&oirq);
 520 }
 521 EXPORT_SYMBOL_GPL(of_irq_parse_and_map_pci);
 522 #endif  /* CONFIG_OF_IRQ */
 523
 524 int pci_parse_request_of_pci_ranges(struct device *dev,
 525                                     struct list_head *resources,
 526                                     struct list_head *ib_resources,
 527                                     struct resource **bus_range)
 528 {
 529         int err, res_valid = 0;
 530         resource_size_t iobase;
 531         struct resource_entry *win, *tmp;
 532
 533         INIT_LIST_HEAD(resources);
 534         if (ib_resources)
 535                 INIT_LIST_HEAD(ib_resources);
 536         err = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff, resources,
 537                                                     ib_resources, &iobase);
 538         if (err)
 539                 return err;
 540
 541         err = devm_request_pci_bus_resources(dev, resources);
 542         if (err)
 543                 goto out_release_res;
 544
 545         resource_list_for_each_entry_safe(win, tmp, resources) {
 546                 struct resource *res = win->res;
 547
 548                 switch (resource_type(res)) {
 549                 case IORESOURCE_IO:
 550                         err = devm_pci_remap_iospace(dev, res, iobase);
 551                         if (err) {
 552                                 dev_warn(dev, "error %d: failed to map resource %pR\n",
 553                                          err, res);
 554                                 resource_list_destroy_entry(win);
 555                         }
 556                         break;
 557                 case IORESOURCE_MEM:
 558                         res_valid |= !(res->flags & IORESOURCE_PREFETCH);
 559                         break;
 560                 case IORESOURCE_BUS:
 561                         if (bus_range)
 562                                 *bus_range = res;
 563                         break;
 564                 }
 565         }
 566
 567         if (res_valid)
 568                 return 0;
 569
 570         dev_err(dev, "non-prefetchable memory resource required\n");
 571         err = -EINVAL;
 572
 573  out_release_res:
 574         pci_free_resource_list(resources);
 575         return err;
 576 }
 577 EXPORT_SYMBOL_GPL(pci_parse_request_of_pci_ranges);
 578
 579 #endif /* CONFIG_PCI */
 580
 581 /**
 582  * This function will try to find the limitation of link speed by finding
 583  * a property called "max-link-speed" of the given device node.
 584  *
 585  * @node: device tree node with the max link speed information
 586  *
 587  * Returns the associated max link speed from DT, or a negative value if the
 588  * required property is not found or is invalid.
 589  */
 590 int of_pci_get_max_link_speed(struct device_node *node)
 591 {
 592         u32 max_link_speed;
 593
 594         if (of_property_read_u32(node, "max-link-speed", &max_link_speed) ||
 595             max_link_speed > 4)
 596                 return -EINVAL;
 597
 598         return max_link_speed;
 599 }
 600 EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed);