drivers/core/of_addr.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Taken from Linux v4.9 drivers/of/address.c
   4  *
   5  * Modified for U-Boot
   6  * Copyright (c) 2017 Google, Inc
   7  */
   8
   9 #include <common.h>
  10 #include <log.h>
  11 #include <linux/bug.h>
  12 #include <linux/libfdt.h>
  13 #include <dm/of_access.h>
  14 #include <dm/of_addr.h>
  15 #include <linux/err.h>
  16 #include <linux/ioport.h>
  17
  18 /* Max address size we deal with */
  19 #define OF_MAX_ADDR_CELLS       4
  20 #define OF_CHECK_ADDR_COUNT(na) ((na) > 0 && (na) <= OF_MAX_ADDR_CELLS)
  21 #define OF_CHECK_COUNTS(na, ns) (OF_CHECK_ADDR_COUNT(na) && (ns) > 0)
  22
  23 static struct of_bus *of_match_bus(struct device_node *np);
  24
  25 /* Debug utility */
  26 #ifdef DEBUG
  27 static void of_dump_addr(const char *s, const __be32 *addr, int na)
  28 {
  29         debug("%s", s);
  30         while (na--)
  31                 pr_cont(" %08x", be32_to_cpu(*(addr++)));
  32         pr_cont("\n");
  33 }
  34 #else
  35 static void of_dump_addr(const char *s, const __be32 *addr, int na) { }
  36 #endif
  37
  38 /* Callbacks for bus specific translators */
  39 struct of_bus {
  40         const char *name;
  41         const char *addresses;
  42         int (*match)(struct device_node *parent);
  43         void (*count_cells)(const struct device_node *child, int *addrc,
  44                             int *sizec);
  45         u64 (*map)(__be32 *addr, const __be32 *range, int na, int ns, int pna);
  46         int (*translate)(__be32 *addr, u64 offset, int na);
  47         unsigned int (*get_flags)(const __be32 *addr);
  48 };
  49
  50 static void of_bus_default_count_cells(const struct device_node *np,
  51                                        int *addrc, int *sizec)
  52 {
  53         if (addrc)
  54                 *addrc = of_n_addr_cells(np);
  55         if (sizec)
  56                 *sizec = of_n_size_cells(np);
  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         debug("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 /*
  95  * Array of bus-specific translators
  96  */
  97 static struct of_bus of_busses[] = {
  98         /* Default */
  99         {
 100                 .name = "default",
 101                 .addresses = "reg",
 102                 .match = NULL,
 103                 .count_cells = of_bus_default_count_cells,
 104                 .map = of_bus_default_map,
 105                 .translate = of_bus_default_translate,
 106                 .get_flags = of_bus_default_get_flags,
 107         },
 108 };
 109
 110 static struct of_bus *of_match_bus(struct device_node *np)
 111 {
 112         int i;
 113
 114         for (i = 0; i < ARRAY_SIZE(of_busses); i++)
 115                 if (!of_busses[i].match || of_busses[i].match(np))
 116                         return &of_busses[i];
 117         BUG();
 118         return NULL;
 119 }
 120
 121 static void dev_count_cells(const struct device_node *np, int *nap, int *nsp)
 122 {
 123         of_bus_default_count_cells(np, nap, nsp);
 124 }
 125
 126 const __be32 *of_get_address(const struct device_node *dev, int index,
 127                              u64 *size, unsigned int *flags)
 128 {
 129         const __be32 *prop;
 130         int psize;
 131         struct device_node *parent;
 132         struct of_bus *bus;
 133         int onesize, i, na, ns;
 134
 135         /* Get parent & match bus type */
 136         parent = of_get_parent(dev);
 137         if (parent == NULL)
 138                 return NULL;
 139         dev_count_cells(dev, &na, &ns);
 140         bus = of_match_bus(parent);
 141         bus->count_cells(dev, &na, &ns);
 142         of_node_put(parent);
 143         if (!OF_CHECK_ADDR_COUNT(na))
 144                 return NULL;
 145
 146         /* Get "reg" or "assigned-addresses" property */
 147         prop = of_get_property(dev, "reg", &psize);
 148         if (prop == NULL)
 149                 return NULL;
 150         psize /= 4;
 151
 152         onesize = na + ns;
 153         for (i = 0; psize >= onesize; psize -= onesize, prop += onesize, i++)
 154                 if (i == index) {
 155                         if (size)
 156                                 *size = of_read_number(prop + na, ns);
 157                         if (flags)
 158                                 *flags = bus->get_flags(prop);
 159                         return prop;
 160                 }
 161         return NULL;
 162 }
 163 EXPORT_SYMBOL(of_get_address);
 164
 165 static int of_empty_ranges_quirk(const struct device_node *np)
 166 {
 167         return false;
 168 }
 169
 170 static int of_translate_one(const struct device_node *parent,
 171                             struct of_bus *bus, struct of_bus *pbus,
 172                             __be32 *addr, int na, int ns, int pna,
 173                             const char *rprop)
 174 {
 175         const __be32 *ranges;
 176         int rlen;
 177         int rone;
 178         u64 offset = OF_BAD_ADDR;
 179
 180         /*
 181          * Normally, an absence of a "ranges" property means we are
 182          * crossing a non-translatable boundary, and thus the addresses
 183          * below the current cannot be converted to CPU physical ones.
 184          * Unfortunately, while this is very clear in the spec, it's not
 185          * what Apple understood, and they do have things like /uni-n or
 186          * /ht nodes with no "ranges" property and a lot of perfectly
 187          * useable mapped devices below them. Thus we treat the absence of
 188          * "ranges" as equivalent to an empty "ranges" property which means
 189          * a 1:1 translation at that level. It's up to the caller not to try
 190          * to translate addresses that aren't supposed to be translated in
 191          * the first place. --BenH.
 192          *
 193          * As far as we know, this damage only exists on Apple machines, so
 194          * This code is only enabled on powerpc. --gcl
 195          */
 196         ranges = of_get_property(parent, rprop, &rlen);
 197         if (ranges == NULL && !of_empty_ranges_quirk(parent)) {
 198                 debug("no ranges; cannot translate\n");
 199                 return 1;
 200         }
 201         if (ranges == NULL || rlen == 0) {
 202                 offset = of_read_number(addr, na);
 203                 memset(addr, 0, pna * 4);
 204                 debug("empty ranges; 1:1 translation\n");
 205                 goto finish;
 206         }
 207
 208         debug("walking ranges...\n");
 209
 210         /* Now walk through the ranges */
 211         rlen /= 4;
 212         rone = na + pna + ns;
 213         for (; rlen >= rone; rlen -= rone, ranges += rone) {
 214                 offset = bus->map(addr, ranges, na, ns, pna);
 215                 if (offset != OF_BAD_ADDR)
 216                         break;
 217         }
 218         if (offset == OF_BAD_ADDR) {
 219                 debug("not found !\n");
 220                 return 1;
 221         }
 222         memcpy(addr, ranges + na, 4 * pna);
 223
 224  finish:
 225         of_dump_addr("parent translation for:", addr, pna);
 226         debug("with offset: %llx\n", (unsigned long long)offset);
 227
 228         /* Translate it into parent bus space */
 229         return pbus->translate(addr, offset, pna);
 230 }
 231
 232 /*
 233  * Translate an address from the device-tree into a CPU physical address,
 234  * this walks up the tree and applies the various bus mappings on the
 235  * way.
 236  *
 237  * Note: We consider that crossing any level with #size-cells == 0 to mean
 238  * that translation is impossible (that is we are not dealing with a value
 239  * that can be mapped to a cpu physical address). This is not really specified
 240  * that way, but this is traditionally the way IBM at least do things
 241  */
 242 static u64 __of_translate_address(const struct device_node *dev,
 243                                   const __be32 *in_addr, const char *rprop)
 244 {
 245         struct device_node *parent = NULL;
 246         struct of_bus *bus, *pbus;
 247         __be32 addr[OF_MAX_ADDR_CELLS];
 248         int na, ns, pna, pns;
 249         u64 result = OF_BAD_ADDR;
 250
 251         debug("** translation for device %s **\n", of_node_full_name(dev));
 252
 253         /* Increase refcount at current level */
 254         (void)of_node_get(dev);
 255
 256         /* Get parent & match bus type */
 257         parent = of_get_parent(dev);
 258         if (parent == NULL)
 259                 goto bail;
 260         bus = of_match_bus(parent);
 261
 262         /* Count address cells & copy address locally */
 263         bus->count_cells(dev, &na, &ns);
 264         if (!OF_CHECK_COUNTS(na, ns)) {
 265                 debug("Bad cell count for %s\n", of_node_full_name(dev));
 266                 goto bail;
 267         }
 268         memcpy(addr, in_addr, na * 4);
 269
 270         debug("bus is %s (na=%d, ns=%d) on %s\n", bus->name, na, ns,
 271               of_node_full_name(parent));
 272         of_dump_addr("translating address:", addr, na);
 273
 274         /* Translate */
 275         for (;;) {
 276                 /* Switch to parent bus */
 277                 of_node_put(dev);
 278                 dev = parent;
 279                 parent = of_get_parent(dev);
 280
 281                 /* If root, we have finished */
 282                 if (parent == NULL) {
 283                         debug("reached root node\n");
 284                         result = of_read_number(addr, na);
 285                         break;
 286                 }
 287
 288                 /* Get new parent bus and counts */
 289                 pbus = of_match_bus(parent);
 290                 pbus->count_cells(dev, &pna, &pns);
 291                 if (!OF_CHECK_COUNTS(pna, pns)) {
 292                         debug("Bad cell count for %s\n",
 293                               of_node_full_name(dev));
 294                         break;
 295                 }
 296
 297                 debug("parent bus is %s (na=%d, ns=%d) on %s\n", pbus->name,
 298                       pna, pns, of_node_full_name(parent));
 299
 300                 /* Apply bus translation */
 301                 if (of_translate_one(dev, bus, pbus, addr, na, ns, pna, rprop))
 302                         break;
 303
 304                 /* Complete the move up one level */
 305                 na = pna;
 306                 ns = pns;
 307                 bus = pbus;
 308
 309                 of_dump_addr("one level translation:", addr, na);
 310         }
 311  bail:
 312         of_node_put(parent);
 313         of_node_put(dev);
 314
 315         return result;
 316 }
 317
 318 u64 of_translate_address(const struct device_node *dev, const __be32 *in_addr)
 319 {
 320         return __of_translate_address(dev, in_addr, "ranges");
 321 }
 322
 323 u64 of_translate_dma_address(const struct device_node *dev, const __be32 *in_addr)
 324 {
 325         return __of_translate_address(dev, in_addr, "dma-ranges");
 326 }
 327
 328 static int __of_address_to_resource(const struct device_node *dev,
 329                 const __be32 *addrp, u64 size, unsigned int flags,
 330                 const char *name, struct resource *r)
 331 {
 332         u64 taddr;
 333
 334         if ((flags & (IORESOURCE_IO | IORESOURCE_MEM)) == 0)
 335                 return -EINVAL;
 336         taddr = of_translate_address(dev, addrp);
 337         if (taddr == OF_BAD_ADDR)
 338                 return -EINVAL;
 339         memset(r, 0, sizeof(struct resource));
 340         r->start = taddr;
 341         r->end = taddr + size - 1;
 342         r->flags = flags;
 343         r->name = name ? name : dev->full_name;
 344
 345         return 0;
 346 }
 347
 348 int of_address_to_resource(const struct device_node *dev, int index,
 349                            struct resource *r)
 350 {
 351         const __be32    *addrp;
 352         u64             size;
 353         unsigned int    flags;
 354         const char      *name = NULL;
 355
 356         addrp = of_get_address(dev, index, &size, &flags);
 357         if (addrp == NULL)
 358                 return -EINVAL;
 359
 360         /* Get optional "reg-names" property to add a name to a resource */
 361         of_property_read_string_index(dev, "reg-names", index, &name);
 362
 363         return __of_address_to_resource(dev, addrp, size, flags, name, r);
 364 }