1 // SPDX-License-Identifier: GPL-2.0+
3 * Taken from Linux v4.9 drivers/of/address.c
6 * Copyright (c) 2017 Google, Inc
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>
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)
23 static struct of_bus *of_match_bus(struct device_node *np);
27 static void of_dump_addr(const char *s, const __be32 *addr, int na)
31 pr_cont(" %08x", be32_to_cpu(*(addr++)));
35 static void of_dump_addr(const char *s, const __be32 *addr, int na) { }
38 /* Callbacks for bus specific translators */
41 const char *addresses;
42 int (*match)(struct device_node *parent);
43 void (*count_cells)(const struct device_node *child, int *addrc,
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);
50 static void of_bus_default_count_cells(const struct device_node *np,
51 int *addrc, int *sizec)
54 *addrc = of_n_addr_cells(np);
56 *sizec = of_n_size_cells(np);
59 static u64 of_bus_default_map(__be32 *addr, const __be32 *range,
60 int na, int ns, int pna)
64 cp = of_read_number(range, na);
65 s = of_read_number(range + na + pna, ns);
66 da = of_read_number(addr, na);
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);
72 if (da < cp || da >= (cp + s))
77 static int of_bus_default_translate(__be32 *addr, u64 offset, int na)
79 u64 a = of_read_number(addr, na);
80 memset(addr, 0, na * 4);
83 addr[na - 2] = cpu_to_be32(a >> 32);
84 addr[na - 1] = cpu_to_be32(a & 0xffffffffu);
89 static unsigned int of_bus_default_get_flags(const __be32 *addr)
91 return IORESOURCE_MEM;
95 * Array of bus-specific translators
97 static struct of_bus of_busses[] = {
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,
110 static struct of_bus *of_match_bus(struct device_node *np)
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];
121 const __be32 *of_get_address(const struct device_node *dev, int index,
122 u64 *size, unsigned int *flags)
126 struct device_node *parent;
128 int onesize, i, na, ns;
130 /* Get parent & match bus type */
131 parent = of_get_parent(dev);
134 bus = of_match_bus(parent);
135 bus->count_cells(dev, &na, &ns);
137 if (!OF_CHECK_ADDR_COUNT(na))
140 /* Get "reg" or "assigned-addresses" property */
141 prop = of_get_property(dev, "reg", &psize);
147 for (i = 0; psize >= onesize; psize -= onesize, prop += onesize, i++)
150 *size = of_read_number(prop + na, ns);
152 *flags = bus->get_flags(prop);
157 EXPORT_SYMBOL(of_get_address);
159 static int of_empty_ranges_quirk(const struct device_node *np)
164 static int of_translate_one(const struct device_node *parent,
165 struct of_bus *bus, struct of_bus *pbus,
166 __be32 *addr, int na, int ns, int pna,
169 const __be32 *ranges;
172 u64 offset = OF_BAD_ADDR;
175 * Normally, an absence of a "ranges" property means we are
176 * crossing a non-translatable boundary, and thus the addresses
177 * below the current cannot be converted to CPU physical ones.
178 * Unfortunately, while this is very clear in the spec, it's not
179 * what Apple understood, and they do have things like /uni-n or
180 * /ht nodes with no "ranges" property and a lot of perfectly
181 * useable mapped devices below them. Thus we treat the absence of
182 * "ranges" as equivalent to an empty "ranges" property which means
183 * a 1:1 translation at that level. It's up to the caller not to try
184 * to translate addresses that aren't supposed to be translated in
185 * the first place. --BenH.
187 * As far as we know, this damage only exists on Apple machines, so
188 * This code is only enabled on powerpc. --gcl
190 * This quirk also applies for 'dma-ranges' which frequently exist in
191 * child nodes without 'dma-ranges' in the parent nodes. --RobH
193 ranges = of_get_property(parent, rprop, &rlen);
194 if (ranges == NULL && !of_empty_ranges_quirk(parent) &&
195 strcmp(rprop, "dma-ranges")) {
196 debug("no ranges; cannot translate\n");
199 if (ranges == NULL || rlen == 0) {
200 offset = of_read_number(addr, na);
201 memset(addr, 0, pna * 4);
202 debug("empty ranges; 1:1 translation\n");
206 debug("walking ranges...\n");
208 /* Now walk through the ranges */
210 rone = na + pna + ns;
211 for (; rlen >= rone; rlen -= rone, ranges += rone) {
212 offset = bus->map(addr, ranges, na, ns, pna);
213 if (offset != OF_BAD_ADDR)
216 if (offset == OF_BAD_ADDR) {
217 debug("not found !\n");
220 memcpy(addr, ranges + na, 4 * pna);
223 of_dump_addr("parent translation for:", addr, pna);
224 debug("with offset: %llx\n", (unsigned long long)offset);
226 /* Translate it into parent bus space */
227 return pbus->translate(addr, offset, pna);
231 * Translate an address from the device-tree into a CPU physical address,
232 * this walks up the tree and applies the various bus mappings on the
235 * Note: We consider that crossing any level with #size-cells == 0 to mean
236 * that translation is impossible (that is we are not dealing with a value
237 * that can be mapped to a cpu physical address). This is not really specified
238 * that way, but this is traditionally the way IBM at least do things
240 static u64 __of_translate_address(const struct device_node *dev,
241 const __be32 *in_addr, const char *rprop)
243 struct device_node *parent = NULL;
244 struct of_bus *bus, *pbus;
245 __be32 addr[OF_MAX_ADDR_CELLS];
246 int na, ns, pna, pns;
247 u64 result = OF_BAD_ADDR;
249 debug("** translation for device %s **\n", of_node_full_name(dev));
251 /* Increase refcount at current level */
252 (void)of_node_get(dev);
254 /* Get parent & match bus type */
255 parent = of_get_parent(dev);
258 bus = of_match_bus(parent);
260 /* Count address cells & copy address locally */
261 bus->count_cells(dev, &na, &ns);
262 if (!OF_CHECK_COUNTS(na, ns)) {
263 debug("Bad cell count for %s\n", of_node_full_name(dev));
266 memcpy(addr, in_addr, na * 4);
268 debug("bus is %s (na=%d, ns=%d) on %s\n", bus->name, na, ns,
269 of_node_full_name(parent));
270 of_dump_addr("translating address:", addr, na);
274 /* Switch to parent bus */
277 parent = of_get_parent(dev);
279 /* If root, we have finished */
280 if (parent == NULL) {
281 debug("reached root node\n");
282 result = of_read_number(addr, na);
286 /* Get new parent bus and counts */
287 pbus = of_match_bus(parent);
288 pbus->count_cells(dev, &pna, &pns);
289 if (!OF_CHECK_COUNTS(pna, pns)) {
290 debug("Bad cell count for %s\n",
291 of_node_full_name(dev));
295 debug("parent bus is %s (na=%d, ns=%d) on %s\n", pbus->name,
296 pna, pns, of_node_full_name(parent));
298 /* Apply bus translation */
299 if (of_translate_one(dev, bus, pbus, addr, na, ns, pna, rprop))
302 /* Complete the move up one level */
307 of_dump_addr("one level translation:", addr, na);
316 u64 of_translate_address(const struct device_node *dev, const __be32 *in_addr)
318 return __of_translate_address(dev, in_addr, "ranges");
321 u64 of_translate_dma_address(const struct device_node *dev, const __be32 *in_addr)
323 return __of_translate_address(dev, in_addr, "dma-ranges");
326 int of_get_dma_range(const struct device_node *dev, phys_addr_t *cpu,
327 dma_addr_t *bus, u64 *size)
329 bool found_dma_ranges = false;
330 struct device_node *parent;
331 struct of_bus *bus_node;
332 int na, ns, pna, pns;
333 const __be32 *ranges;
337 /* Find the closest dma-ranges property */
338 dev = of_node_get(dev);
340 ranges = of_get_property(dev, "dma-ranges", &len);
342 /* Ignore empty ranges, they imply no translation required */
343 if (ranges && len > 0)
346 /* Once we find 'dma-ranges', then a missing one is an error */
347 if (found_dma_ranges && !ranges) {
353 found_dma_ranges = true;
355 parent = of_get_parent(dev);
360 if (!dev || !ranges) {
361 debug("no dma-ranges found for node %s\n",
362 of_node_full_name(dev));
367 /* switch to that node */
368 parent = of_get_parent(dev);
370 printf("Found dma-ranges in root node, shoudln't happen\n");
375 /* Get the address sizes both for the bus and its parent */
376 bus_node = of_match_bus((struct device_node*)dev);
377 bus_node->count_cells(dev, &na, &ns);
378 if (!OF_CHECK_COUNTS(na, ns)) {
379 printf("Bad cell count for %s\n", of_node_full_name(dev));
384 bus_node = of_match_bus(parent);
385 bus_node->count_cells(parent, &pna, &pns);
386 if (!OF_CHECK_COUNTS(pna, pns)) {
387 printf("Bad cell count for %s\n", of_node_full_name(parent));
392 *bus = of_read_number(ranges, na);
393 *cpu = of_translate_dma_address(dev, ranges + na);
394 *size = of_read_number(ranges + na + pna, ns);
404 static int __of_address_to_resource(const struct device_node *dev,
405 const __be32 *addrp, u64 size, unsigned int flags,
406 const char *name, struct resource *r)
410 if ((flags & (IORESOURCE_IO | IORESOURCE_MEM)) == 0)
412 taddr = of_translate_address(dev, addrp);
413 if (taddr == OF_BAD_ADDR)
415 memset(r, 0, sizeof(struct resource));
417 r->end = taddr + size - 1;
419 r->name = name ? name : dev->full_name;
424 int of_address_to_resource(const struct device_node *dev, int index,
430 const char *name = NULL;
432 addrp = of_get_address(dev, index, &size, &flags);
436 /* Get optional "reg-names" property to add a name to a resource */
437 of_property_read_string_index(dev, "reg-names", index, &name);
439 return __of_address_to_resource(dev, addrp, size, flags, name, r);