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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 <linux/libfdt.h>
11 #include <dm/of_access.h>
12 #include <dm/of_addr.h>
13 #include <linux/err.h>
14 #include <linux/ioport.h>
15 
16 /* Max address size we deal with */
17 #define OF_MAX_ADDR_CELLS	4
18 #define OF_CHECK_ADDR_COUNT(na)	((na) > 0 && (na) <= OF_MAX_ADDR_CELLS)
19 #define OF_CHECK_COUNTS(na, ns)	(OF_CHECK_ADDR_COUNT(na) && (ns) > 0)
20 
21 static struct of_bus *of_match_bus(struct device_node *np);
22 
23 /* Debug utility */
24 #ifdef DEBUG
of_dump_addr(const char * s,const __be32 * addr,int na)25 static void of_dump_addr(const char *s, const __be32 *addr, int na)
26 {
27 	debug("%s", s);
28 	while (na--)
29 		pr_cont(" %08x", be32_to_cpu(*(addr++)));
30 	pr_cont("\n");
31 }
32 #else
of_dump_addr(const char * s,const __be32 * addr,int na)33 static void of_dump_addr(const char *s, const __be32 *addr, int na) { }
34 #endif
35 
36 /* Callbacks for bus specific translators */
37 struct of_bus {
38 	const char *name;
39 	const char *addresses;
40 	int (*match)(struct device_node *parent);
41 	void (*count_cells)(const struct device_node *child, int *addrc,
42 			    int *sizec);
43 	u64 (*map)(__be32 *addr, const __be32 *range, int na, int ns, int pna);
44 	int (*translate)(__be32 *addr, u64 offset, int na);
45 	unsigned int (*get_flags)(const __be32 *addr);
46 };
47 
of_bus_default_count_cells(const struct device_node * np,int * addrc,int * sizec)48 static void of_bus_default_count_cells(const struct device_node *np,
49 				       int *addrc, int *sizec)
50 {
51 	if (addrc)
52 		*addrc = of_n_addr_cells(np);
53 	if (sizec)
54 		*sizec = of_n_size_cells(np);
55 }
56 
of_bus_default_map(__be32 * addr,const __be32 * range,int na,int ns,int pna)57 static u64 of_bus_default_map(__be32 *addr, const __be32 *range,
58 		int na, int ns, int pna)
59 {
60 	u64 cp, s, da;
61 
62 	cp = of_read_number(range, na);
63 	s  = of_read_number(range + na + pna, ns);
64 	da = of_read_number(addr, na);
65 
66 	debug("default map, cp=%llx, s=%llx, da=%llx\n",
67 	      (unsigned long long)cp, (unsigned long long)s,
68 	      (unsigned long long)da);
69 
70 	if (da < cp || da >= (cp + s))
71 		return OF_BAD_ADDR;
72 	return da - cp;
73 }
74 
of_bus_default_translate(__be32 * addr,u64 offset,int na)75 static int of_bus_default_translate(__be32 *addr, u64 offset, int na)
76 {
77 	u64 a = of_read_number(addr, na);
78 	memset(addr, 0, na * 4);
79 	a += offset;
80 	if (na > 1)
81 		addr[na - 2] = cpu_to_be32(a >> 32);
82 	addr[na - 1] = cpu_to_be32(a & 0xffffffffu);
83 
84 	return 0;
85 }
86 
of_bus_default_get_flags(const __be32 * addr)87 static unsigned int of_bus_default_get_flags(const __be32 *addr)
88 {
89 	return IORESOURCE_MEM;
90 }
91 
92 /*
93  * Array of bus-specific translators
94  */
95 static struct of_bus of_busses[] = {
96 	/* Default */
97 	{
98 		.name = "default",
99 		.addresses = "reg",
100 		.match = NULL,
101 		.count_cells = of_bus_default_count_cells,
102 		.map = of_bus_default_map,
103 		.translate = of_bus_default_translate,
104 		.get_flags = of_bus_default_get_flags,
105 	},
106 };
107 
of_match_bus(struct device_node * np)108 static struct of_bus *of_match_bus(struct device_node *np)
109 {
110 	int i;
111 
112 	for (i = 0; i < ARRAY_SIZE(of_busses); i++)
113 		if (!of_busses[i].match || of_busses[i].match(np))
114 			return &of_busses[i];
115 	BUG();
116 	return NULL;
117 }
118 
dev_count_cells(const struct device_node * np,int * nap,int * nsp)119 static void dev_count_cells(const struct device_node *np, int *nap, int *nsp)
120 {
121 	of_bus_default_count_cells(np, nap, nsp);
122 }
123 
of_get_address(const struct device_node * dev,int index,u64 * size,unsigned int * flags)124 const __be32 *of_get_address(const struct device_node *dev, int index,
125 			     u64 *size, unsigned int *flags)
126 {
127 	const __be32 *prop;
128 	int psize;
129 	struct device_node *parent;
130 	struct of_bus *bus;
131 	int onesize, i, na, ns;
132 
133 	/* Get parent & match bus type */
134 	parent = of_get_parent(dev);
135 	if (parent == NULL)
136 		return NULL;
137 	dev_count_cells(dev, &na, &ns);
138 	bus = of_match_bus(parent);
139 	bus->count_cells(dev, &na, &ns);
140 	of_node_put(parent);
141 	if (!OF_CHECK_ADDR_COUNT(na))
142 		return NULL;
143 
144 	/* Get "reg" or "assigned-addresses" property */
145 	prop = of_get_property(dev, "reg", &psize);
146 	if (prop == NULL)
147 		return NULL;
148 	psize /= 4;
149 
150 	onesize = na + ns;
151 	for (i = 0; psize >= onesize; psize -= onesize, prop += onesize, i++)
152 		if (i == index) {
153 			if (size)
154 				*size = of_read_number(prop + na, ns);
155 			if (flags)
156 				*flags = bus->get_flags(prop);
157 			return prop;
158 		}
159 	return NULL;
160 }
161 EXPORT_SYMBOL(of_get_address);
162 
of_empty_ranges_quirk(const struct device_node * np)163 static int of_empty_ranges_quirk(const struct device_node *np)
164 {
165 	return false;
166 }
167 
of_translate_one(const struct device_node * parent,struct of_bus * bus,struct of_bus * pbus,__be32 * addr,int na,int ns,int pna,const char * rprop)168 static int of_translate_one(const struct device_node *parent,
169 			    struct of_bus *bus, struct of_bus *pbus,
170 			    __be32 *addr, int na, int ns, int pna,
171 			    const char *rprop)
172 {
173 	const __be32 *ranges;
174 	int rlen;
175 	int rone;
176 	u64 offset = OF_BAD_ADDR;
177 
178 	/*
179 	 * Normally, an absence of a "ranges" property means we are
180 	 * crossing a non-translatable boundary, and thus the addresses
181 	 * below the current cannot be converted to CPU physical ones.
182 	 * Unfortunately, while this is very clear in the spec, it's not
183 	 * what Apple understood, and they do have things like /uni-n or
184 	 * /ht nodes with no "ranges" property and a lot of perfectly
185 	 * useable mapped devices below them. Thus we treat the absence of
186 	 * "ranges" as equivalent to an empty "ranges" property which means
187 	 * a 1:1 translation at that level. It's up to the caller not to try
188 	 * to translate addresses that aren't supposed to be translated in
189 	 * the first place. --BenH.
190 	 *
191 	 * As far as we know, this damage only exists on Apple machines, so
192 	 * This code is only enabled on powerpc. --gcl
193 	 */
194 	ranges = of_get_property(parent, rprop, &rlen);
195 	if (ranges == NULL && !of_empty_ranges_quirk(parent)) {
196 		debug("no ranges; cannot translate\n");
197 		return 1;
198 	}
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");
203 		goto finish;
204 	}
205 
206 	debug("walking ranges...\n");
207 
208 	/* Now walk through the ranges */
209 	rlen /= 4;
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)
214 			break;
215 	}
216 	if (offset == OF_BAD_ADDR) {
217 		debug("not found !\n");
218 		return 1;
219 	}
220 	memcpy(addr, ranges + na, 4 * pna);
221 
222  finish:
223 	of_dump_addr("parent translation for:", addr, pna);
224 	debug("with offset: %llx\n", (unsigned long long)offset);
225 
226 	/* Translate it into parent bus space */
227 	return pbus->translate(addr, offset, pna);
228 }
229 
230 /*
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
233  * way.
234  *
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
239  */
__of_translate_address(const struct device_node * dev,const __be32 * in_addr,const char * rprop)240 static u64 __of_translate_address(const struct device_node *dev,
241 				  const __be32 *in_addr, const char *rprop)
242 {
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;
248 
249 	debug("** translation for device %s **\n", of_node_full_name(dev));
250 
251 	/* Increase refcount at current level */
252 	(void)of_node_get(dev);
253 
254 	/* Get parent & match bus type */
255 	parent = of_get_parent(dev);
256 	if (parent == NULL)
257 		goto bail;
258 	bus = of_match_bus(parent);
259 
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));
264 		goto bail;
265 	}
266 	memcpy(addr, in_addr, na * 4);
267 
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);
271 
272 	/* Translate */
273 	for (;;) {
274 		/* Switch to parent bus */
275 		of_node_put(dev);
276 		dev = parent;
277 		parent = of_get_parent(dev);
278 
279 		/* If root, we have finished */
280 		if (parent == NULL) {
281 			debug("reached root node\n");
282 			result = of_read_number(addr, na);
283 			break;
284 		}
285 
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));
292 			break;
293 		}
294 
295 		debug("parent bus is %s (na=%d, ns=%d) on %s\n", pbus->name,
296 		      pna, pns, of_node_full_name(parent));
297 
298 		/* Apply bus translation */
299 		if (of_translate_one(dev, bus, pbus, addr, na, ns, pna, rprop))
300 			break;
301 
302 		/* Complete the move up one level */
303 		na = pna;
304 		ns = pns;
305 		bus = pbus;
306 
307 		of_dump_addr("one level translation:", addr, na);
308 	}
309  bail:
310 	of_node_put(parent);
311 	of_node_put(dev);
312 
313 	return result;
314 }
315 
of_translate_address(const struct device_node * dev,const __be32 * in_addr)316 u64 of_translate_address(const struct device_node *dev, const __be32 *in_addr)
317 {
318 	return __of_translate_address(dev, in_addr, "ranges");
319 }
320 
321 
__of_address_to_resource(const struct device_node * dev,const __be32 * addrp,u64 size,unsigned int flags,const char * name,struct resource * r)322 static int __of_address_to_resource(const struct device_node *dev,
323 		const __be32 *addrp, u64 size, unsigned int flags,
324 		const char *name, struct resource *r)
325 {
326 	u64 taddr;
327 
328 	if ((flags & (IORESOURCE_IO | IORESOURCE_MEM)) == 0)
329 		return -EINVAL;
330 	taddr = of_translate_address(dev, addrp);
331 	if (taddr == OF_BAD_ADDR)
332 		return -EINVAL;
333 	memset(r, 0, sizeof(struct resource));
334 	r->start = taddr;
335 	r->end = taddr + size - 1;
336 	r->flags = flags;
337 	r->name = name ? name : dev->full_name;
338 
339 	return 0;
340 }
341 
of_address_to_resource(const struct device_node * dev,int index,struct resource * r)342 int of_address_to_resource(const struct device_node *dev, int index,
343 			   struct resource *r)
344 {
345 	const __be32	*addrp;
346 	u64		size;
347 	unsigned int	flags;
348 	const char	*name = NULL;
349 
350 	addrp = of_get_address(dev, index, &size, &flags);
351 	if (addrp == NULL)
352 		return -EINVAL;
353 
354 	/* Get optional "reg-names" property to add a name to a resource */
355 	of_property_read_string_index(dev, "reg-names", index, &name);
356 
357 	return __of_address_to_resource(dev, addrp, size, flags, name, r);
358 }
359