drivers/of/address.c

   1
   2 #include <linux/device.h>
   3 #include <linux/io.h>
   4 #include <linux/ioport.h>
   5 #include <linux/module.h>
   6 #include <linux/of_address.h>
   7 #include <linux/pci_regs.h>
   8 #include <linux/string.h>
   9
  10 /* Max address size we deal with */
  11 #define OF_MAX_ADDR_CELLS       4
  12 #define OF_CHECK_ADDR_COUNT(na) ((na) > 0 && (na) <= OF_MAX_ADDR_CELLS)
  13 #define OF_CHECK_COUNTS(na, ns) (OF_CHECK_ADDR_COUNT(na) && (ns) > 0)
  14
  15 static struct of_bus *of_match_bus(struct device_node *np);
  16 static int __of_address_to_resource(struct device_node *dev,
  17                 const __be32 *addrp, u64 size, unsigned int flags,
  18                 const char *name, struct resource *r);
  19
  20 /* Debug utility */
  21 #ifdef DEBUG
  22 static void of_dump_addr(const char *s, const __be32 *addr, int na)
  23 {
  24         printk(KERN_DEBUG "%s", s);
  25         while (na--)
  26                 printk(" %08x", be32_to_cpu(*(addr++)));
  27         printk("\n");
  28 }
  29 #else
  30 static void of_dump_addr(const char *s, const __be32 *addr, int na) { }
  31 #endif
  32
  33 /* Callbacks for bus specific translators */
  34 struct of_bus {
  35         const char      *name;
  36         const char      *addresses;
  37         int             (*match)(struct device_node *parent);
  38         void            (*count_cells)(struct device_node *child,
  39                                        int *addrc, int *sizec);
  40         u64             (*map)(__be32 *addr, const __be32 *range,
  41                                 int na, int ns, int pna);
  42         int             (*translate)(__be32 *addr, u64 offset, int na);
  43         unsigned int    (*get_flags)(const __be32 *addr);
  44 };
  45
  46 /*
  47  * Default translator (generic bus)
  48  */
  49
  50 static void of_bus_default_count_cells(struct device_node *dev,
  51                                        int *addrc, int *sizec)
  52 {
  53         if (addrc)
  54                 *addrc = of_n_addr_cells(dev);
  55         if (sizec)
  56                 *sizec = of_n_size_cells(dev);
  57 }
  58
  59 static u64 of_bus_default_map(__be32 *addr, const __be32 *range,
  60                 int na, int ns, int pna)
  61 {
  62         u64 cp, s, da;
  63
  64         cp = of_read_number(range, na);
  65         s  = of_read_number(range + na + pna, ns);
  66         da = of_read_number(addr, na);
  67
  68         pr_debug("OF: default map, cp=%llx, s=%llx, da=%llx\n",
  69                  (unsigned long long)cp, (unsigned long long)s,
  70                  (unsigned long long)da);
  71
  72         if (da < cp || da >= (cp + s))
  73                 return OF_BAD_ADDR;
  74         return da - cp;
  75 }
  76
  77 static int of_bus_default_translate(__be32 *addr, u64 offset, int na)
  78 {
  79         u64 a = of_read_number(addr, na);
  80         memset(addr, 0, na * 4);
  81         a += offset;
  82         if (na > 1)
  83                 addr[na - 2] = cpu_to_be32(a >> 32);
  84         addr[na - 1] = cpu_to_be32(a & 0xffffffffu);
  85
  86         return 0;
  87 }
  88
  89 static unsigned int of_bus_default_get_flags(const __be32 *addr)
  90 {
  91         return IORESOURCE_MEM;
  92 }
  93
  94 #ifdef CONFIG_PCI
  95 /*
  96  * PCI bus specific translator
  97  */
  98
  99 static int of_bus_pci_match(struct device_node *np)
 100 {
 101         /*
 102          * "pciex" is PCI Express
 103          * "vci" is for the /chaos bridge on 1st-gen PCI powermacs
 104          * "ht" is hypertransport
 105          */
 106         return !strcmp(np->type, "pci") || !strcmp(np->type, "pciex") ||
 107                 !strcmp(np->type, "vci") || !strcmp(np->type, "ht");
 108 }
 109
 110 static void of_bus_pci_count_cells(struct device_node *np,
 111                                    int *addrc, int *sizec)
 112 {
 113         if (addrc)
 114                 *addrc = 3;
 115         if (sizec)
 116                 *sizec = 2;
 117 }
 118
 119 static unsigned int of_bus_pci_get_flags(const __be32 *addr)
 120 {
 121         unsigned int flags = 0;
 122         u32 w = be32_to_cpup(addr);
 123
 124         switch((w >> 24) & 0x03) {
 125         case 0x01:
 126                 flags |= IORESOURCE_IO;
 127                 break;
 128         case 0x02: /* 32 bits */
 129         case 0x03: /* 64 bits */
 130                 flags |= IORESOURCE_MEM;
 131                 break;
 132         }
 133         if (w & 0x40000000)
 134                 flags |= IORESOURCE_PREFETCH;
 135         return flags;
 136 }
 137
 138 static u64 of_bus_pci_map(__be32 *addr, const __be32 *range, int na, int ns,
 139                 int pna)
 140 {
 141         u64 cp, s, da;
 142         unsigned int af, rf;
 143
 144         af = of_bus_pci_get_flags(addr);
 145         rf = of_bus_pci_get_flags(range);
 146
 147         /* Check address type match */
 148         if ((af ^ rf) & (IORESOURCE_MEM | IORESOURCE_IO))
 149                 return OF_BAD_ADDR;
 150
 151         /* Read address values, skipping high cell */
 152         cp = of_read_number(range + 1, na - 1);
 153         s  = of_read_number(range + na + pna, ns);
 154         da = of_read_number(addr + 1, na - 1);
 155
 156         pr_debug("OF: PCI map, cp=%llx, s=%llx, da=%llx\n",
 157                  (unsigned long long)cp, (unsigned long long)s,
 158                  (unsigned long long)da);
 159
 160         if (da < cp || da >= (cp + s))
 161                 return OF_BAD_ADDR;
 162         return da - cp;
 163 }
 164
 165 static int of_bus_pci_translate(__be32 *addr, u64 offset, int na)
 166 {
 167         return of_bus_default_translate(addr + 1, offset, na - 1);
 168 }
 169
 170 const __be32 *of_get_pci_address(struct device_node *dev, int bar_no, u64 *size,
 171                         unsigned int *flags)
 172 {
 173         const __be32 *prop;
 174         unsigned int psize;
 175         struct device_node *parent;
 176         struct of_bus *bus;
 177         int onesize, i, na, ns;
 178
 179         /* Get parent & match bus type */
 180         parent = of_get_parent(dev);
 181         if (parent == NULL)
 182                 return NULL;
 183         bus = of_match_bus(parent);
 184         if (strcmp(bus->name, "pci")) {
 185                 of_node_put(parent);
 186                 return NULL;
 187         }
 188         bus->count_cells(dev, &na, &ns);
 189         of_node_put(parent);
 190         if (!OF_CHECK_ADDR_COUNT(na))
 191                 return NULL;
 192
 193         /* Get "reg" or "assigned-addresses" property */
 194         prop = of_get_property(dev, bus->addresses, &psize);
 195         if (prop == NULL)
 196                 return NULL;
 197         psize /= 4;
 198
 199         onesize = na + ns;
 200         for (i = 0; psize >= onesize; psize -= onesize, prop += onesize, i++) {
 201                 u32 val = be32_to_cpu(prop[0]);
 202                 if ((val & 0xff) == ((bar_no * 4) + PCI_BASE_ADDRESS_0)) {
 203                         if (size)
 204                                 *size = of_read_number(prop + na, ns);
 205                         if (flags)
 206                                 *flags = bus->get_flags(prop);
 207                         return prop;
 208                 }
 209         }
 210         return NULL;
 211 }
 212 EXPORT_SYMBOL(of_get_pci_address);
 213
 214 int of_pci_address_to_resource(struct device_node *dev, int bar,
 215                                struct resource *r)
 216 {
 217         const __be32    *addrp;
 218         u64             size;
 219         unsigned int    flags;
 220
 221         addrp = of_get_pci_address(dev, bar, &size, &flags);
 222         if (addrp == NULL)
 223                 return -EINVAL;
 224         return __of_address_to_resource(dev, addrp, size, flags, NULL, r);
 225 }
 226 EXPORT_SYMBOL_GPL(of_pci_address_to_resource);
 227 #endif /* CONFIG_PCI */
 228
 229 /*
 230  * ISA bus specific translator
 231  */
 232
 233 static int of_bus_isa_match(struct device_node *np)
 234 {
 235         return !strcmp(np->name, "isa");
 236 }
 237
 238 static void of_bus_isa_count_cells(struct device_node *child,
 239                                    int *addrc, int *sizec)
 240 {
 241         if (addrc)
 242                 *addrc = 2;
 243         if (sizec)
 244                 *sizec = 1;
 245 }
 246
 247 static u64 of_bus_isa_map(__be32 *addr, const __be32 *range, int na, int ns,
 248                 int pna)
 249 {
 250         u64 cp, s, da;
 251
 252         /* Check address type match */
 253         if ((addr[0] ^ range[0]) & cpu_to_be32(1))
 254                 return OF_BAD_ADDR;
 255
 256         /* Read address values, skipping high cell */
 257         cp = of_read_number(range + 1, na - 1);
 258         s  = of_read_number(range + na + pna, ns);
 259         da = of_read_number(addr + 1, na - 1);
 260
 261         pr_debug("OF: ISA map, cp=%llx, s=%llx, da=%llx\n",
 262                  (unsigned long long)cp, (unsigned long long)s,
 263                  (unsigned long long)da);
 264
 265         if (da < cp || da >= (cp + s))
 266                 return OF_BAD_ADDR;
 267         return da - cp;
 268 }
 269
 270 static int of_bus_isa_translate(__be32 *addr, u64 offset, int na)
 271 {
 272         return of_bus_default_translate(addr + 1, offset, na - 1);
 273 }
 274
 275 static unsigned int of_bus_isa_get_flags(const __be32 *addr)
 276 {
 277         unsigned int flags = 0;
 278         u32 w = be32_to_cpup(addr);
 279
 280         if (w & 1)
 281                 flags |= IORESOURCE_IO;
 282         else
 283                 flags |= IORESOURCE_MEM;
 284         return flags;
 285 }
 286
 287 /*
 288  * Array of bus specific translators
 289  */
 290
 291 static struct of_bus of_busses[] = {
 292 #ifdef CONFIG_PCI
 293         /* PCI */
 294         {
 295                 .name = "pci",
 296                 .addresses = "assigned-addresses",
 297                 .match = of_bus_pci_match,
 298                 .count_cells = of_bus_pci_count_cells,
 299                 .map = of_bus_pci_map,
 300                 .translate = of_bus_pci_translate,
 301                 .get_flags = of_bus_pci_get_flags,
 302         },
 303 #endif /* CONFIG_PCI */
 304         /* ISA */
 305         {
 306                 .name = "isa",
 307                 .addresses = "reg",
 308                 .match = of_bus_isa_match,
 309                 .count_cells = of_bus_isa_count_cells,
 310                 .map = of_bus_isa_map,
 311                 .translate = of_bus_isa_translate,
 312                 .get_flags = of_bus_isa_get_flags,
 313         },
 314         /* Default */
 315         {
 316                 .name = "default",
 317                 .addresses = "reg",
 318                 .match = NULL,
 319                 .count_cells = of_bus_default_count_cells,
 320                 .map = of_bus_default_map,
 321                 .translate = of_bus_default_translate,
 322                 .get_flags = of_bus_default_get_flags,
 323         },
 324 };
 325
 326 static struct of_bus *of_match_bus(struct device_node *np)
 327 {
 328         int i;
 329
 330         for (i = 0; i < ARRAY_SIZE(of_busses); i++)
 331                 if (!of_busses[i].match || of_busses[i].match(np))
 332                         return &of_busses[i];
 333         BUG();
 334         return NULL;
 335 }
 336
 337 static int of_empty_ranges_quirk(void)
 338 {
 339         if (IS_ENABLED(CONFIG_PPC)) {
 340                 /* To save cycles, we cache the result */
 341                 static int quirk_state = -1;
 342
 343                 if (quirk_state < 0)
 344                         quirk_state =
 345                                 of_machine_is_compatible("Power Macintosh") ||
 346                                 of_machine_is_compatible("MacRISC");
 347                 return quirk_state;
 348         }
 349         return false;
 350 }
 351
 352 static int of_translate_one(struct device_node *parent, struct of_bus *bus,
 353                             struct of_bus *pbus, __be32 *addr,
 354                             int na, int ns, int pna, const char *rprop)
 355 {
 356         const __be32 *ranges;
 357         unsigned int rlen;
 358         int rone;
 359         u64 offset = OF_BAD_ADDR;
 360
 361         /* Normally, an absence of a "ranges" property means we are
 362          * crossing a non-translatable boundary, and thus the addresses
 363          * below the current not cannot be converted to CPU physical ones.
 364          * Unfortunately, while this is very clear in the spec, it's not
 365          * what Apple understood, and they do have things like /uni-n or
 366          * /ht nodes with no "ranges" property and a lot of perfectly
 367          * useable mapped devices below them. Thus we treat the absence of
 368          * "ranges" as equivalent to an empty "ranges" property which means
 369          * a 1:1 translation at that level. It's up to the caller not to try
 370          * to translate addresses that aren't supposed to be translated in
 371          * the first place. --BenH.
 372          *
 373          * As far as we know, this damage only exists on Apple machines, so
 374          * This code is only enabled on powerpc. --gcl
 375          */
 376         ranges = of_get_property(parent, rprop, &rlen);
 377         if (ranges == NULL && !of_empty_ranges_quirk()) {
 378                 pr_err("OF: no ranges; cannot translate\n");
 379                 return 1;
 380         }
 381         if (ranges == NULL || rlen == 0) {
 382                 offset = of_read_number(addr, na);
 383                 memset(addr, 0, pna * 4);
 384                 pr_debug("OF: empty ranges; 1:1 translation\n");
 385                 goto finish;
 386         }
 387
 388         pr_debug("OF: walking ranges...\n");
 389
 390         /* Now walk through the ranges */
 391         rlen /= 4;
 392         rone = na + pna + ns;
 393         for (; rlen >= rone; rlen -= rone, ranges += rone) {
 394                 offset = bus->map(addr, ranges, na, ns, pna);
 395                 if (offset != OF_BAD_ADDR)
 396                         break;
 397         }
 398         if (offset == OF_BAD_ADDR) {
 399                 pr_debug("OF: not found !\n");
 400                 return 1;
 401         }
 402         memcpy(addr, ranges + na, 4 * pna);
 403
 404  finish:
 405         of_dump_addr("OF: parent translation for:", addr, pna);
 406         pr_debug("OF: with offset: %llx\n", (unsigned long long)offset);
 407
 408         /* Translate it into parent bus space */
 409         return pbus->translate(addr, offset, pna);
 410 }
 411
 412 /*
 413  * Translate an address from the device-tree into a CPU physical address,
 414  * this walks up the tree and applies the various bus mappings on the
 415  * way.
 416  *
 417  * Note: We consider that crossing any level with #size-cells == 0 to mean
 418  * that translation is impossible (that is we are not dealing with a value
 419  * that can be mapped to a cpu physical address). This is not really specified
 420  * that way, but this is traditionally the way IBM at least do things
 421  */
 422 static u64 __of_translate_address(struct device_node *dev,
 423                                   const __be32 *in_addr, const char *rprop)
 424 {
 425         struct device_node *parent = NULL;
 426         struct of_bus *bus, *pbus;
 427         __be32 addr[OF_MAX_ADDR_CELLS];
 428         int na, ns, pna, pns;
 429         u64 result = OF_BAD_ADDR;
 430
 431         pr_debug("OF: ** translation for device %s **\n", dev->full_name);
 432
 433         /* Increase refcount at current level */
 434         of_node_get(dev);
 435
 436         /* Get parent & match bus type */
 437         parent = of_get_parent(dev);
 438         if (parent == NULL)
 439                 goto bail;
 440         bus = of_match_bus(parent);
 441
 442         /* Count address cells & copy address locally */
 443         bus->count_cells(dev, &na, &ns);
 444         if (!OF_CHECK_COUNTS(na, ns)) {
 445                 printk(KERN_ERR "prom_parse: Bad cell count for %s\n",
 446                        dev->full_name);
 447                 goto bail;
 448         }
 449         memcpy(addr, in_addr, na * 4);
 450
 451         pr_debug("OF: bus is %s (na=%d, ns=%d) on %s\n",
 452             bus->name, na, ns, parent->full_name);
 453         of_dump_addr("OF: translating address:", addr, na);
 454
 455         /* Translate */
 456         for (;;) {
 457                 /* Switch to parent bus */
 458                 of_node_put(dev);
 459                 dev = parent;
 460                 parent = of_get_parent(dev);
 461
 462                 /* If root, we have finished */
 463                 if (parent == NULL) {
 464                         pr_debug("OF: reached root node\n");
 465                         result = of_read_number(addr, na);
 466                         break;
 467                 }
 468
 469                 /* Get new parent bus and counts */
 470                 pbus = of_match_bus(parent);
 471                 pbus->count_cells(dev, &pna, &pns);
 472                 if (!OF_CHECK_COUNTS(pna, pns)) {
 473                         printk(KERN_ERR "prom_parse: Bad cell count for %s\n",
 474                                dev->full_name);
 475                         break;
 476                 }
 477
 478                 pr_debug("OF: parent bus is %s (na=%d, ns=%d) on %s\n",
 479                     pbus->name, pna, pns, parent->full_name);
 480
 481                 /* Apply bus translation */
 482                 if (of_translate_one(dev, bus, pbus, addr, na, ns, pna, rprop))
 483                         break;
 484
 485                 /* Complete the move up one level */
 486                 na = pna;
 487                 ns = pns;
 488                 bus = pbus;
 489
 490                 of_dump_addr("OF: one level translation:", addr, na);
 491         }
 492  bail:
 493         of_node_put(parent);
 494         of_node_put(dev);
 495
 496         return result;
 497 }
 498
 499 u64 of_translate_address(struct device_node *dev, const __be32 *in_addr)
 500 {
 501         return __of_translate_address(dev, in_addr, "ranges");
 502 }
 503 EXPORT_SYMBOL(of_translate_address);
 504
 505 u64 of_translate_dma_address(struct device_node *dev, const __be32 *in_addr)
 506 {
 507         return __of_translate_address(dev, in_addr, "dma-ranges");
 508 }
 509 EXPORT_SYMBOL(of_translate_dma_address);
 510
 511 bool of_can_translate_address(struct device_node *dev)
 512 {
 513         struct device_node *parent;
 514         struct of_bus *bus;
 515         int na, ns;
 516
 517         parent = of_get_parent(dev);
 518         if (parent == NULL)
 519                 return false;
 520
 521         bus = of_match_bus(parent);
 522         bus->count_cells(dev, &na, &ns);
 523
 524         of_node_put(parent);
 525
 526         return OF_CHECK_COUNTS(na, ns);
 527 }
 528 EXPORT_SYMBOL(of_can_translate_address);
 529
 530 const __be32 *of_get_address(struct device_node *dev, int index, u64 *size,
 531                     unsigned int *flags)
 532 {
 533         const __be32 *prop;
 534         unsigned int psize;
 535         struct device_node *parent;
 536         struct of_bus *bus;
 537         int onesize, i, na, ns;
 538
 539         /* Get parent & match bus type */
 540         parent = of_get_parent(dev);
 541         if (parent == NULL)
 542                 return NULL;
 543         bus = of_match_bus(parent);
 544         bus->count_cells(dev, &na, &ns);
 545         of_node_put(parent);
 546         if (!OF_CHECK_ADDR_COUNT(na))
 547                 return NULL;
 548
 549         /* Get "reg" or "assigned-addresses" property */
 550         prop = of_get_property(dev, bus->addresses, &psize);
 551         if (prop == NULL)
 552                 return NULL;
 553         psize /= 4;
 554
 555         onesize = na + ns;
 556         for (i = 0; psize >= onesize; psize -= onesize, prop += onesize, i++)
 557                 if (i == index) {
 558                         if (size)
 559                                 *size = of_read_number(prop + na, ns);
 560                         if (flags)
 561                                 *flags = bus->get_flags(prop);
 562                         return prop;
 563                 }
 564         return NULL;
 565 }
 566 EXPORT_SYMBOL(of_get_address);
 567
 568 static int __of_address_to_resource(struct device_node *dev,
 569                 const __be32 *addrp, u64 size, unsigned int flags,
 570                 const char *name, struct resource *r)
 571 {
 572         u64 taddr;
 573
 574         if ((flags & (IORESOURCE_IO | IORESOURCE_MEM)) == 0)
 575                 return -EINVAL;
 576         taddr = of_translate_address(dev, addrp);
 577         if (taddr == OF_BAD_ADDR)
 578                 return -EINVAL;
 579         memset(r, 0, sizeof(struct resource));
 580         if (flags & IORESOURCE_IO) {
 581                 unsigned long port;
 582                 port = pci_address_to_pio(taddr);
 583                 if (port == (unsigned long)-1)
 584                         return -EINVAL;
 585                 r->start = port;
 586                 r->end = port + size - 1;
 587         } else {
 588                 r->start = taddr;
 589                 r->end = taddr + size - 1;
 590         }
 591         r->flags = flags;
 592         r->name = name ? name : dev->full_name;
 593
 594         return 0;
 595 }
 596
 597 /**
 598  * of_address_to_resource - Translate device tree address and return as resource
 599  *
 600  * Note that if your address is a PIO address, the conversion will fail if
 601  * the physical address can't be internally converted to an IO token with
 602  * pci_address_to_pio(), that is because it's either called to early or it
 603  * can't be matched to any host bridge IO space
 604  */
 605 int of_address_to_resource(struct device_node *dev, int index,
 606                            struct resource *r)
 607 {
 608         const __be32    *addrp;
 609         u64             size;
 610         unsigned int    flags;
 611         const char      *name = NULL;
 612
 613         addrp = of_get_address(dev, index, &size, &flags);
 614         if (addrp == NULL)
 615                 return -EINVAL;
 616
 617         /* Get optional "reg-names" property to add a name to a resource */
 618         of_property_read_string_index(dev, "reg-names", index, &name);
 619
 620         return __of_address_to_resource(dev, addrp, size, flags, name, r);
 621 }
 622 EXPORT_SYMBOL_GPL(of_address_to_resource);
 623
 624 struct device_node *of_find_matching_node_by_address(struct device_node *from,
 625                                         const struct of_device_id *matches,
 626                                         u64 base_address)
 627 {
 628         struct device_node *dn = of_find_matching_node(from, matches);
 629         struct resource res;
 630
 631         while (dn) {
 632                 if (of_address_to_resource(dn, 0, &res))
 633                         continue;
 634                 if (res.start == base_address)
 635                         return dn;
 636                 dn = of_find_matching_node(dn, matches);
 637         }
 638
 639         return NULL;
 640 }
 641
 642
 643 /**
 644  * of_iomap - Maps the memory mapped IO for a given device_node
 645  * @device:     the device whose io range will be mapped
 646  * @index:      index of the io range
 647  *
 648  * Returns a pointer to the mapped memory
 649  */
 650 void __iomem *of_iomap(struct device_node *np, int index)
 651 {
 652         struct resource res;
 653
 654         if (of_address_to_resource(np, index, &res))
 655                 return NULL;
 656
 657         return ioremap(res.start, resource_size(&res));
 658 }
 659 EXPORT_SYMBOL(of_iomap);