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 void pci_set_of_node(struct pci_dev *dev)
  19 {
  20         if (!dev->bus->dev.of_node)
  21                 return;
  22         dev->dev.of_node = of_pci_find_child_device(dev->bus->dev.of_node,
  23                                                     dev->devfn);
  24 }
  25
  26 void pci_release_of_node(struct pci_dev *dev)
  27 {
  28         of_node_put(dev->dev.of_node);
  29         dev->dev.of_node = NULL;
  30 }
  31
  32 void pci_set_bus_of_node(struct pci_bus *bus)
  33 {
  34         if (bus->self == NULL)
  35                 bus->dev.of_node = pcibios_get_phb_of_node(bus);
  36         else
  37                 bus->dev.of_node = of_node_get(bus->self->dev.of_node);
  38 }
  39
  40 void pci_release_bus_of_node(struct pci_bus *bus)
  41 {
  42         of_node_put(bus->dev.of_node);
  43         bus->dev.of_node = NULL;
  44 }
  45
  46 struct device_node * __weak pcibios_get_phb_of_node(struct pci_bus *bus)
  47 {
  48         /* This should only be called for PHBs */
  49         if (WARN_ON(bus->self || bus->parent))
  50                 return NULL;
  51
  52         /*
  53          * Look for a node pointer in either the intermediary device we
  54          * create above the root bus or its own parent. Normally only
  55          * the later is populated.
  56          */
  57         if (bus->bridge->of_node)
  58                 return of_node_get(bus->bridge->of_node);
  59         if (bus->bridge->parent && bus->bridge->parent->of_node)
  60                 return of_node_get(bus->bridge->parent->of_node);
  61         return NULL;
  62 }
  63
  64 struct irq_domain *pci_host_bridge_of_msi_domain(struct pci_bus *bus)
  65 {
  66 #ifdef CONFIG_IRQ_DOMAIN
  67         struct irq_domain *d;
  68
  69         if (!bus->dev.of_node)
  70                 return NULL;
  71
  72         /* Start looking for a phandle to an MSI controller. */
  73         d = of_msi_get_domain(&bus->dev, bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
  74         if (d)
  75                 return d;
  76
  77         /*
  78          * If we don't have an msi-parent property, look for a domain
  79          * directly attached to the host bridge.
  80          */
  81         d = irq_find_matching_host(bus->dev.of_node, DOMAIN_BUS_PCI_MSI);
  82         if (d)
  83                 return d;
  84
  85         return irq_find_host(bus->dev.of_node);
  86 #else
  87         return NULL;
  88 #endif
  89 }
  90
  91 static inline int __of_pci_pci_compare(struct device_node *node,
  92                                        unsigned int data)
  93 {
  94         int devfn;
  95
  96         devfn = of_pci_get_devfn(node);
  97         if (devfn < 0)
  98                 return 0;
  99
 100         return devfn == data;
 101 }
 102
 103 struct device_node *of_pci_find_child_device(struct device_node *parent,
 104                                              unsigned int devfn)
 105 {
 106         struct device_node *node, *node2;
 107
 108         for_each_child_of_node(parent, node) {
 109                 if (__of_pci_pci_compare(node, devfn))
 110                         return node;
 111                 /*
 112                  * Some OFs create a parent node "multifunc-device" as
 113                  * a fake root for all functions of a multi-function
 114                  * device we go down them as well.
 115                  */
 116                 if (!strcmp(node->name, "multifunc-device")) {
 117                         for_each_child_of_node(node, node2) {
 118                                 if (__of_pci_pci_compare(node2, devfn)) {
 119                                         of_node_put(node);
 120                                         return node2;
 121                                 }
 122                         }
 123                 }
 124         }
 125         return NULL;
 126 }
 127 EXPORT_SYMBOL_GPL(of_pci_find_child_device);
 128
 129 /**
 130  * of_pci_get_devfn() - Get device and function numbers for a device node
 131  * @np: device node
 132  *
 133  * Parses a standard 5-cell PCI resource and returns an 8-bit value that can
 134  * be passed to the PCI_SLOT() and PCI_FUNC() macros to extract the device
 135  * and function numbers respectively. On error a negative error code is
 136  * returned.
 137  */
 138 int of_pci_get_devfn(struct device_node *np)
 139 {
 140         u32 reg[5];
 141         int error;
 142
 143         error = of_property_read_u32_array(np, "reg", reg, ARRAY_SIZE(reg));
 144         if (error)
 145                 return error;
 146
 147         return (reg[0] >> 8) & 0xff;
 148 }
 149 EXPORT_SYMBOL_GPL(of_pci_get_devfn);
 150
 151 /**
 152  * of_pci_parse_bus_range() - parse the bus-range property of a PCI device
 153  * @node: device node
 154  * @res: address to a struct resource to return the bus-range
 155  *
 156  * Returns 0 on success or a negative error-code on failure.
 157  */
 158 int of_pci_parse_bus_range(struct device_node *node, struct resource *res)
 159 {
 160         u32 bus_range[2];
 161         int error;
 162
 163         error = of_property_read_u32_array(node, "bus-range", bus_range,
 164                                            ARRAY_SIZE(bus_range));
 165         if (error)
 166                 return error;
 167
 168         res->name = node->name;
 169         res->start = bus_range[0];
 170         res->end = bus_range[1];
 171         res->flags = IORESOURCE_BUS;
 172
 173         return 0;
 174 }
 175 EXPORT_SYMBOL_GPL(of_pci_parse_bus_range);
 176
 177 /**
 178  * This function will try to obtain the host bridge domain number by
 179  * finding a property called "linux,pci-domain" of the given device node.
 180  *
 181  * @node: device tree node with the domain information
 182  *
 183  * Returns the associated domain number from DT in the range [0-0xffff], or
 184  * a negative value if the required property is not found.
 185  */
 186 int of_get_pci_domain_nr(struct device_node *node)
 187 {
 188         u32 domain;
 189         int error;
 190
 191         error = of_property_read_u32(node, "linux,pci-domain", &domain);
 192         if (error)
 193                 return error;
 194
 195         return (u16)domain;
 196 }
 197 EXPORT_SYMBOL_GPL(of_get_pci_domain_nr);
 198
 199 /**
 200  * This function will try to find the limitation of link speed by finding
 201  * a property called "max-link-speed" of the given device node.
 202  *
 203  * @node: device tree node with the max link speed information
 204  *
 205  * Returns the associated max link speed from DT, or a negative value if the
 206  * required property is not found or is invalid.
 207  */
 208 int of_pci_get_max_link_speed(struct device_node *node)
 209 {
 210         u32 max_link_speed;
 211
 212         if (of_property_read_u32(node, "max-link-speed", &max_link_speed) ||
 213             max_link_speed > 4)
 214                 return -EINVAL;
 215
 216         return max_link_speed;
 217 }
 218 EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed);
 219
 220 /**
 221  * of_pci_check_probe_only - Setup probe only mode if linux,pci-probe-only
 222  *                           is present and valid
 223  */
 224 void of_pci_check_probe_only(void)
 225 {
 226         u32 val;
 227         int ret;
 228
 229         ret = of_property_read_u32(of_chosen, "linux,pci-probe-only", &val);
 230         if (ret) {
 231                 if (ret == -ENODATA || ret == -EOVERFLOW)
 232                         pr_warn("linux,pci-probe-only without valid value, ignoring\n");
 233                 return;
 234         }
 235
 236         if (val)
 237                 pci_add_flags(PCI_PROBE_ONLY);
 238         else
 239                 pci_clear_flags(PCI_PROBE_ONLY);
 240
 241         pr_info("PROBE_ONLY %sabled\n", val ? "en" : "dis");
 242 }
 243 EXPORT_SYMBOL_GPL(of_pci_check_probe_only);
 244
 245 #if defined(CONFIG_OF_ADDRESS)
 246 /**
 247  * of_pci_get_host_bridge_resources - Parse PCI host bridge resources from DT
 248  * @dev: device node of the host bridge having the range property
 249  * @busno: bus number associated with the bridge root bus
 250  * @bus_max: maximum number of buses for this bridge
 251  * @resources: list where the range of resources will be added after DT parsing
 252  * @io_base: pointer to a variable that will contain on return the physical
 253  * address for the start of the I/O range. Can be NULL if the caller doesn't
 254  * expect I/O ranges to be present in the device tree.
 255  *
 256  * It is the caller's job to free the @resources list.
 257  *
 258  * This function will parse the "ranges" property of a PCI host bridge device
 259  * node and setup the resource mapping based on its content. It is expected
 260  * that the property conforms with the Power ePAPR document.
 261  *
 262  * It returns zero if the range parsing has been successful or a standard error
 263  * value if it failed.
 264  */
 265 int of_pci_get_host_bridge_resources(struct device_node *dev,
 266                         unsigned char busno, unsigned char bus_max,
 267                         struct list_head *resources, resource_size_t *io_base)
 268 {
 269         struct resource_entry *window;
 270         struct resource *res;
 271         struct resource *bus_range;
 272         struct of_pci_range range;
 273         struct of_pci_range_parser parser;
 274         char range_type[4];
 275         int err;
 276
 277         if (io_base)
 278                 *io_base = (resource_size_t)OF_BAD_ADDR;
 279
 280         bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL);
 281         if (!bus_range)
 282                 return -ENOMEM;
 283
 284         pr_info("host bridge %pOF ranges:\n", dev);
 285
 286         err = of_pci_parse_bus_range(dev, bus_range);
 287         if (err) {
 288                 bus_range->start = busno;
 289                 bus_range->end = bus_max;
 290                 bus_range->flags = IORESOURCE_BUS;
 291                 pr_info("  No bus range found for %pOF, using %pR\n",
 292                         dev, bus_range);
 293         } else {
 294                 if (bus_range->end > bus_range->start + bus_max)
 295                         bus_range->end = bus_range->start + bus_max;
 296         }
 297         pci_add_resource(resources, bus_range);
 298
 299         /* Check for ranges property */
 300         err = of_pci_range_parser_init(&parser, dev);
 301         if (err)
 302                 goto parse_failed;
 303
 304         pr_debug("Parsing ranges property...\n");
 305         for_each_of_pci_range(&parser, &range) {
 306                 /* Read next ranges element */
 307                 if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO)
 308                         snprintf(range_type, 4, " IO");
 309                 else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM)
 310                         snprintf(range_type, 4, "MEM");
 311                 else
 312                         snprintf(range_type, 4, "err");
 313                 pr_info("  %s %#010llx..%#010llx -> %#010llx\n", range_type,
 314                         range.cpu_addr, range.cpu_addr + range.size - 1,
 315                         range.pci_addr);
 316
 317                 /*
 318                  * If we failed translation or got a zero-sized region
 319                  * then skip this range
 320                  */
 321                 if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
 322                         continue;
 323
 324                 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
 325                 if (!res) {
 326                         err = -ENOMEM;
 327                         goto parse_failed;
 328                 }
 329
 330                 err = of_pci_range_to_resource(&range, dev, res);
 331                 if (err) {
 332                         kfree(res);
 333                         continue;
 334                 }
 335
 336                 if (resource_type(res) == IORESOURCE_IO) {
 337                         if (!io_base) {
 338                                 pr_err("I/O range found for %pOF. Please provide an io_base pointer to save CPU base address\n",
 339                                         dev);
 340                                 err = -EINVAL;
 341                                 goto conversion_failed;
 342                         }
 343                         if (*io_base != (resource_size_t)OF_BAD_ADDR)
 344                                 pr_warn("More than one I/O resource converted for %pOF. CPU base address for old range lost!\n",
 345                                         dev);
 346                         *io_base = range.cpu_addr;
 347                 }
 348
 349                 pci_add_resource_offset(resources, res, res->start - range.pci_addr);
 350         }
 351
 352         return 0;
 353
 354 conversion_failed:
 355         kfree(res);
 356 parse_failed:
 357         resource_list_for_each_entry(window, resources)
 358                 kfree(window->res);
 359         pci_free_resource_list(resources);
 360         return err;
 361 }
 362 EXPORT_SYMBOL_GPL(of_pci_get_host_bridge_resources);
 363 #endif /* CONFIG_OF_ADDRESS */
 364
 365 /**
 366  * of_pci_map_rid - Translate a requester ID through a downstream mapping.
 367  * @np: root complex device node.
 368  * @rid: PCI requester ID to map.
 369  * @map_name: property name of the map to use.
 370  * @map_mask_name: optional property name of the mask to use.
 371  * @target: optional pointer to a target device node.
 372  * @id_out: optional pointer to receive the translated ID.
 373  *
 374  * Given a PCI requester ID, look up the appropriate implementation-defined
 375  * platform ID and/or the target device which receives transactions on that
 376  * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
 377  * @id_out may be NULL if only the other is required. If @target points to
 378  * a non-NULL device node pointer, only entries targeting that node will be
 379  * matched; if it points to a NULL value, it will receive the device node of
 380  * the first matching target phandle, with a reference held.
 381  *
 382  * Return: 0 on success or a standard error code on failure.
 383  */
 384 int of_pci_map_rid(struct device_node *np, u32 rid,
 385                    const char *map_name, const char *map_mask_name,
 386                    struct device_node **target, u32 *id_out)
 387 {
 388         u32 map_mask, masked_rid;
 389         int map_len;
 390         const __be32 *map = NULL;
 391
 392         if (!np || !map_name || (!target && !id_out))
 393                 return -EINVAL;
 394
 395         map = of_get_property(np, map_name, &map_len);
 396         if (!map) {
 397                 if (target)
 398                         return -ENODEV;
 399                 /* Otherwise, no map implies no translation */
 400                 *id_out = rid;
 401                 return 0;
 402         }
 403
 404         if (!map_len || map_len % (4 * sizeof(*map))) {
 405                 pr_err("%pOF: Error: Bad %s length: %d\n", np,
 406                         map_name, map_len);
 407                 return -EINVAL;
 408         }
 409
 410         /* The default is to select all bits. */
 411         map_mask = 0xffffffff;
 412
 413         /*
 414          * Can be overridden by "{iommu,msi}-map-mask" property.
 415          * If of_property_read_u32() fails, the default is used.
 416          */
 417         if (map_mask_name)
 418                 of_property_read_u32(np, map_mask_name, &map_mask);
 419
 420         masked_rid = map_mask & rid;
 421         for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
 422                 struct device_node *phandle_node;
 423                 u32 rid_base = be32_to_cpup(map + 0);
 424                 u32 phandle = be32_to_cpup(map + 1);
 425                 u32 out_base = be32_to_cpup(map + 2);
 426                 u32 rid_len = be32_to_cpup(map + 3);
 427
 428                 if (rid_base & ~map_mask) {
 429                         pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores rid-base (0x%x)\n",
 430                                 np, map_name, map_name,
 431                                 map_mask, rid_base);
 432                         return -EFAULT;
 433                 }
 434
 435                 if (masked_rid < rid_base || masked_rid >= rid_base + rid_len)
 436                         continue;
 437
 438                 phandle_node = of_find_node_by_phandle(phandle);
 439                 if (!phandle_node)
 440                         return -ENODEV;
 441
 442                 if (target) {
 443                         if (*target)
 444                                 of_node_put(phandle_node);
 445                         else
 446                                 *target = phandle_node;
 447
 448                         if (*target != phandle_node)
 449                                 continue;
 450                 }
 451
 452                 if (id_out)
 453                         *id_out = masked_rid - rid_base + out_base;
 454
 455                 pr_debug("%pOF: %s, using mask %08x, rid-base: %08x, out-base: %08x, length: %08x, rid: %08x -> %08x\n",
 456                         np, map_name, map_mask, rid_base, out_base,
 457                         rid_len, rid, masked_rid - rid_base + out_base);
 458                 return 0;
 459         }
 460
 461         pr_err("%pOF: Invalid %s translation - no match for rid 0x%x on %pOF\n",
 462                 np, map_name, rid, target && *target ? *target : NULL);
 463         return -EFAULT;
 464 }
 465
 466 #if IS_ENABLED(CONFIG_OF_IRQ)
 467 /**
 468  * of_irq_parse_pci - Resolve the interrupt for a PCI device
 469  * @pdev:       the device whose interrupt is to be resolved
 470  * @out_irq:    structure of_irq filled by this function
 471  *
 472  * This function resolves the PCI interrupt for a given PCI device. If a
 473  * device-node exists for a given pci_dev, it will use normal OF tree
 474  * walking. If not, it will implement standard swizzling and walk up the
 475  * PCI tree until an device-node is found, at which point it will finish
 476  * resolving using the OF tree walking.
 477  */
 478 static int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq)
 479 {
 480         struct device_node *dn, *ppnode;
 481         struct pci_dev *ppdev;
 482         __be32 laddr[3];
 483         u8 pin;
 484         int rc;
 485
 486         /*
 487          * Check if we have a device node, if yes, fallback to standard
 488          * device tree parsing
 489          */
 490         dn = pci_device_to_OF_node(pdev);
 491         if (dn) {
 492                 rc = of_irq_parse_one(dn, 0, out_irq);
 493                 if (!rc)
 494                         return rc;
 495         }
 496
 497         /*
 498          * Ok, we don't, time to have fun. Let's start by building up an
 499          * interrupt spec.  we assume #interrupt-cells is 1, which is standard
 500          * for PCI. If you do different, then don't use that routine.
 501          */
 502         rc = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin);
 503         if (rc != 0)
 504                 goto err;
 505         /* No pin, exit with no error message. */
 506         if (pin == 0)
 507                 return -ENODEV;
 508
 509         /* Now we walk up the PCI tree */
 510         for (;;) {
 511                 /* Get the pci_dev of our parent */
 512                 ppdev = pdev->bus->self;
 513
 514                 /* Ouch, it's a host bridge... */
 515                 if (ppdev == NULL) {
 516                         ppnode = pci_bus_to_OF_node(pdev->bus);
 517
 518                         /* No node for host bridge ? give up */
 519                         if (ppnode == NULL) {
 520                                 rc = -EINVAL;
 521                                 goto err;
 522                         }
 523                 } else {
 524                         /* We found a P2P bridge, check if it has a node */
 525                         ppnode = pci_device_to_OF_node(ppdev);
 526                 }
 527
 528                 /*
 529                  * Ok, we have found a parent with a device-node, hand over to
 530                  * the OF parsing code.
 531                  * We build a unit address from the linux device to be used for
 532                  * resolution. Note that we use the linux bus number which may
 533                  * not match your firmware bus numbering.
 534                  * Fortunately, in most cases, interrupt-map-mask doesn't
 535                  * include the bus number as part of the matching.
 536                  * You should still be careful about that though if you intend
 537                  * to rely on this function (you ship a firmware that doesn't
 538                  * create device nodes for all PCI devices).
 539                  */
 540                 if (ppnode)
 541                         break;
 542
 543                 /*
 544                  * We can only get here if we hit a P2P bridge with no node;
 545                  * let's do standard swizzling and try again
 546                  */
 547                 pin = pci_swizzle_interrupt_pin(pdev, pin);
 548                 pdev = ppdev;
 549         }
 550
 551         out_irq->np = ppnode;
 552         out_irq->args_count = 1;
 553         out_irq->args[0] = pin;
 554         laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8));
 555         laddr[1] = laddr[2] = cpu_to_be32(0);
 556         rc = of_irq_parse_raw(laddr, out_irq);
 557         if (rc)
 558                 goto err;
 559         return 0;
 560 err:
 561         if (rc == -ENOENT) {
 562                 dev_warn(&pdev->dev,
 563                         "%s: no interrupt-map found, INTx interrupts not available\n",
 564                         __func__);
 565                 pr_warn_once("%s: possibly some PCI slots don't have level triggered interrupts capability\n",
 566                         __func__);
 567         } else {
 568                 dev_err(&pdev->dev, "%s: failed with rc=%d\n", __func__, rc);
 569         }
 570         return rc;
 571 }
 572
 573 /**
 574  * of_irq_parse_and_map_pci() - Decode a PCI IRQ from the device tree and map to a VIRQ
 575  * @dev: The PCI device needing an IRQ
 576  * @slot: PCI slot number; passed when used as map_irq callback. Unused
 577  * @pin: PCI IRQ pin number; passed when used as map_irq callback. Unused
 578  *
 579  * @slot and @pin are unused, but included in the function so that this
 580  * function can be used directly as the map_irq callback to
 581  * pci_assign_irq() and struct pci_host_bridge.map_irq pointer
 582  */
 583 int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin)
 584 {
 585         struct of_phandle_args oirq;
 586         int ret;
 587
 588         ret = of_irq_parse_pci(dev, &oirq);
 589         if (ret)
 590                 return 0; /* Proper return code 0 == NO_IRQ */
 591
 592         return irq_create_of_mapping(&oirq);
 593 }
 594 EXPORT_SYMBOL_GPL(of_irq_parse_and_map_pci);
 595 #endif  /* CONFIG_OF_IRQ */
 596
 597 int pci_parse_request_of_pci_ranges(struct device *dev,
 598                                     struct list_head *resources,
 599                                     struct resource **bus_range)
 600 {
 601         int err, res_valid = 0;
 602         struct device_node *np = dev->of_node;
 603         resource_size_t iobase;
 604         struct resource_entry *win, *tmp;
 605
 606         INIT_LIST_HEAD(resources);
 607         err = of_pci_get_host_bridge_resources(np, 0, 0xff, resources, &iobase);
 608         if (err)
 609                 return err;
 610
 611         err = devm_request_pci_bus_resources(dev, resources);
 612         if (err)
 613                 goto out_release_res;
 614
 615         resource_list_for_each_entry_safe(win, tmp, resources) {
 616                 struct resource *res = win->res;
 617
 618                 switch (resource_type(res)) {
 619                 case IORESOURCE_IO:
 620                         err = pci_remap_iospace(res, iobase);
 621                         if (err) {
 622                                 dev_warn(dev, "error %d: failed to map resource %pR\n",
 623                                          err, res);
 624                                 resource_list_destroy_entry(win);
 625                         }
 626                         break;
 627                 case IORESOURCE_MEM:
 628                         res_valid |= !(res->flags & IORESOURCE_PREFETCH);
 629                         break;
 630                 case IORESOURCE_BUS:
 631                         if (bus_range)
 632                                 *bus_range = res;
 633                         break;
 634                 }
 635         }
 636
 637         if (res_valid)
 638                 return 0;
 639
 640         dev_err(dev, "non-prefetchable memory resource required\n");
 641         err = -EINVAL;
 642
 643  out_release_res:
 644         pci_free_resource_list(resources);
 645         return err;
 646 }
 647