1 /*
2 * Functions for working with the Flattened Device Tree data format
3 *
4 * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
5 * benh@kernel.crashing.org
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * version 2 as published by the Free Software Foundation.
10 */
11
12 #include <linux/crc32.h>
13 #include <linux/kernel.h>
14 #include <linux/initrd.h>
15 #include <linux/memblock.h>
16 #include <linux/mutex.h>
17 #include <linux/of.h>
18 #include <linux/of_fdt.h>
19 #include <linux/of_reserved_mem.h>
20 #include <linux/sizes.h>
21 #include <linux/string.h>
22 #include <linux/errno.h>
23 #include <linux/slab.h>
24 #include <linux/libfdt.h>
25 #include <linux/debugfs.h>
26 #include <linux/serial_core.h>
27 #include <linux/sysfs.h>
28
29 #include <asm/setup.h> /* for COMMAND_LINE_SIZE */
30 #include <asm/page.h>
31
32 /*
33 * of_fdt_limit_memory - limit the number of regions in the /memory node
34 * @limit: maximum entries
35 *
36 * Adjust the flattened device tree to have at most 'limit' number of
37 * memory entries in the /memory node. This function may be called
38 * any time after initial_boot_param is set.
39 */
of_fdt_limit_memory(int limit)40 void of_fdt_limit_memory(int limit)
41 {
42 int memory;
43 int len;
44 const void *val;
45 int nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
46 int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
47 const uint32_t *addr_prop;
48 const uint32_t *size_prop;
49 int root_offset;
50 int cell_size;
51
52 root_offset = fdt_path_offset(initial_boot_params, "/");
53 if (root_offset < 0)
54 return;
55
56 addr_prop = fdt_getprop(initial_boot_params, root_offset,
57 "#address-cells", NULL);
58 if (addr_prop)
59 nr_address_cells = fdt32_to_cpu(*addr_prop);
60
61 size_prop = fdt_getprop(initial_boot_params, root_offset,
62 "#size-cells", NULL);
63 if (size_prop)
64 nr_size_cells = fdt32_to_cpu(*size_prop);
65
66 cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells);
67
68 memory = fdt_path_offset(initial_boot_params, "/memory");
69 if (memory > 0) {
70 val = fdt_getprop(initial_boot_params, memory, "reg", &len);
71 if (len > limit*cell_size) {
72 len = limit*cell_size;
73 pr_debug("Limiting number of entries to %d\n", limit);
74 fdt_setprop(initial_boot_params, memory, "reg", val,
75 len);
76 }
77 }
78 }
79
80 /**
81 * of_fdt_is_compatible - Return true if given node from the given blob has
82 * compat in its compatible list
83 * @blob: A device tree blob
84 * @node: node to test
85 * @compat: compatible string to compare with compatible list.
86 *
87 * On match, returns a non-zero value with smaller values returned for more
88 * specific compatible values.
89 */
of_fdt_is_compatible(const void * blob,unsigned long node,const char * compat)90 int of_fdt_is_compatible(const void *blob,
91 unsigned long node, const char *compat)
92 {
93 const char *cp;
94 int cplen;
95 unsigned long l, score = 0;
96
97 cp = fdt_getprop(blob, node, "compatible", &cplen);
98 if (cp == NULL)
99 return 0;
100 while (cplen > 0) {
101 score++;
102 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
103 return score;
104 l = strlen(cp) + 1;
105 cp += l;
106 cplen -= l;
107 }
108
109 return 0;
110 }
111
112 /**
113 * of_fdt_is_big_endian - Return true if given node needs BE MMIO accesses
114 * @blob: A device tree blob
115 * @node: node to test
116 *
117 * Returns true if the node has a "big-endian" property, or if the kernel
118 * was compiled for BE *and* the node has a "native-endian" property.
119 * Returns false otherwise.
120 */
of_fdt_is_big_endian(const void * blob,unsigned long node)121 bool of_fdt_is_big_endian(const void *blob, unsigned long node)
122 {
123 if (fdt_getprop(blob, node, "big-endian", NULL))
124 return true;
125 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
126 fdt_getprop(blob, node, "native-endian", NULL))
127 return true;
128 return false;
129 }
130
131 /**
132 * of_fdt_match - Return true if node matches a list of compatible values
133 */
of_fdt_match(const void * blob,unsigned long node,const char * const * compat)134 int of_fdt_match(const void *blob, unsigned long node,
135 const char *const *compat)
136 {
137 unsigned int tmp, score = 0;
138
139 if (!compat)
140 return 0;
141
142 while (*compat) {
143 tmp = of_fdt_is_compatible(blob, node, *compat);
144 if (tmp && (score == 0 || (tmp < score)))
145 score = tmp;
146 compat++;
147 }
148
149 return score;
150 }
151
unflatten_dt_alloc(void ** mem,unsigned long size,unsigned long align)152 static void *unflatten_dt_alloc(void **mem, unsigned long size,
153 unsigned long align)
154 {
155 void *res;
156
157 *mem = PTR_ALIGN(*mem, align);
158 res = *mem;
159 *mem += size;
160
161 return res;
162 }
163
164 /**
165 * unflatten_dt_node - Alloc and populate a device_node from the flat tree
166 * @blob: The parent device tree blob
167 * @mem: Memory chunk to use for allocating device nodes and properties
168 * @poffset: pointer to node in flat tree
169 * @dad: Parent struct device_node
170 * @nodepp: The device_node tree created by the call
171 * @fpsize: Size of the node path up at the current depth.
172 * @dryrun: If true, do not allocate device nodes but still calculate needed
173 * memory size
174 */
unflatten_dt_node(const void * blob,void * mem,int * poffset,struct device_node * dad,struct device_node ** nodepp,unsigned long fpsize,bool dryrun)175 static void * unflatten_dt_node(const void *blob,
176 void *mem,
177 int *poffset,
178 struct device_node *dad,
179 struct device_node **nodepp,
180 unsigned long fpsize,
181 bool dryrun)
182 {
183 const __be32 *p;
184 struct device_node *np;
185 struct property *pp, **prev_pp = NULL;
186 const char *pathp;
187 unsigned int l, allocl;
188 static int depth;
189 int old_depth;
190 int offset;
191 int has_name = 0;
192 int new_format = 0;
193
194 pathp = fdt_get_name(blob, *poffset, &l);
195 if (!pathp)
196 return mem;
197
198 allocl = ++l;
199
200 /* version 0x10 has a more compact unit name here instead of the full
201 * path. we accumulate the full path size using "fpsize", we'll rebuild
202 * it later. We detect this because the first character of the name is
203 * not '/'.
204 */
205 if ((*pathp) != '/') {
206 new_format = 1;
207 if (fpsize == 0) {
208 /* root node: special case. fpsize accounts for path
209 * plus terminating zero. root node only has '/', so
210 * fpsize should be 2, but we want to avoid the first
211 * level nodes to have two '/' so we use fpsize 1 here
212 */
213 fpsize = 1;
214 allocl = 2;
215 l = 1;
216 pathp = "";
217 } else {
218 /* account for '/' and path size minus terminal 0
219 * already in 'l'
220 */
221 fpsize += l;
222 allocl = fpsize;
223 }
224 }
225
226 np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
227 __alignof__(struct device_node));
228 if (!dryrun) {
229 char *fn;
230 of_node_init(np);
231 np->full_name = fn = ((char *)np) + sizeof(*np);
232 if (new_format) {
233 /* rebuild full path for new format */
234 if (dad && dad->parent) {
235 strcpy(fn, dad->full_name);
236 #ifdef DEBUG
237 if ((strlen(fn) + l + 1) != allocl) {
238 pr_debug("%s: p: %d, l: %d, a: %d\n",
239 pathp, (int)strlen(fn),
240 l, allocl);
241 }
242 #endif
243 fn += strlen(fn);
244 }
245 *(fn++) = '/';
246 }
247 memcpy(fn, pathp, l);
248
249 prev_pp = &np->properties;
250 if (dad != NULL) {
251 np->parent = dad;
252 np->sibling = dad->child;
253 dad->child = np;
254 }
255 }
256 /* process properties */
257 for (offset = fdt_first_property_offset(blob, *poffset);
258 (offset >= 0);
259 (offset = fdt_next_property_offset(blob, offset))) {
260 const char *pname;
261 u32 sz;
262
263 if (!(p = fdt_getprop_by_offset(blob, offset, &pname, &sz))) {
264 offset = -FDT_ERR_INTERNAL;
265 break;
266 }
267
268 if (pname == NULL) {
269 pr_info("Can't find property name in list !\n");
270 break;
271 }
272 if (strcmp(pname, "name") == 0)
273 has_name = 1;
274 pp = unflatten_dt_alloc(&mem, sizeof(struct property),
275 __alignof__(struct property));
276 if (!dryrun) {
277 /* We accept flattened tree phandles either in
278 * ePAPR-style "phandle" properties, or the
279 * legacy "linux,phandle" properties. If both
280 * appear and have different values, things
281 * will get weird. Don't do that. */
282 if ((strcmp(pname, "phandle") == 0) ||
283 (strcmp(pname, "linux,phandle") == 0)) {
284 if (np->phandle == 0)
285 np->phandle = be32_to_cpup(p);
286 }
287 /* And we process the "ibm,phandle" property
288 * used in pSeries dynamic device tree
289 * stuff */
290 if (strcmp(pname, "ibm,phandle") == 0)
291 np->phandle = be32_to_cpup(p);
292 pp->name = (char *)pname;
293 pp->length = sz;
294 pp->value = (__be32 *)p;
295 *prev_pp = pp;
296 prev_pp = &pp->next;
297 }
298 }
299 /* with version 0x10 we may not have the name property, recreate
300 * it here from the unit name if absent
301 */
302 if (!has_name) {
303 const char *p1 = pathp, *ps = pathp, *pa = NULL;
304 int sz;
305
306 while (*p1) {
307 if ((*p1) == '@')
308 pa = p1;
309 if ((*p1) == '/')
310 ps = p1 + 1;
311 p1++;
312 }
313 if (pa < ps)
314 pa = p1;
315 sz = (pa - ps) + 1;
316 pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
317 __alignof__(struct property));
318 if (!dryrun) {
319 pp->name = "name";
320 pp->length = sz;
321 pp->value = pp + 1;
322 *prev_pp = pp;
323 prev_pp = &pp->next;
324 memcpy(pp->value, ps, sz - 1);
325 ((char *)pp->value)[sz - 1] = 0;
326 pr_debug("fixed up name for %s -> %s\n", pathp,
327 (char *)pp->value);
328 }
329 }
330 if (!dryrun) {
331 *prev_pp = NULL;
332 np->name = of_get_property(np, "name", NULL);
333 np->type = of_get_property(np, "device_type", NULL);
334
335 if (!np->name)
336 np->name = "<NULL>";
337 if (!np->type)
338 np->type = "<NULL>";
339 }
340
341 old_depth = depth;
342 *poffset = fdt_next_node(blob, *poffset, &depth);
343 if (depth < 0)
344 depth = 0;
345 while (*poffset > 0 && depth > old_depth)
346 mem = unflatten_dt_node(blob, mem, poffset, np, NULL,
347 fpsize, dryrun);
348
349 if (*poffset < 0 && *poffset != -FDT_ERR_NOTFOUND)
350 pr_err("unflatten: error %d processing FDT\n", *poffset);
351
352 /*
353 * Reverse the child list. Some drivers assumes node order matches .dts
354 * node order
355 */
356 if (!dryrun && np->child) {
357 struct device_node *child = np->child;
358 np->child = NULL;
359 while (child) {
360 struct device_node *next = child->sibling;
361 child->sibling = np->child;
362 np->child = child;
363 child = next;
364 }
365 }
366
367 if (nodepp)
368 *nodepp = np;
369
370 return mem;
371 }
372
373 /**
374 * __unflatten_device_tree - create tree of device_nodes from flat blob
375 *
376 * unflattens a device-tree, creating the
377 * tree of struct device_node. It also fills the "name" and "type"
378 * pointers of the nodes so the normal device-tree walking functions
379 * can be used.
380 * @blob: The blob to expand
381 * @mynodes: The device_node tree created by the call
382 * @dt_alloc: An allocator that provides a virtual address to memory
383 * for the resulting tree
384 */
__unflatten_device_tree(const void * blob,struct device_node ** mynodes,void * (* dt_alloc)(u64 size,u64 align))385 static void __unflatten_device_tree(const void *blob,
386 struct device_node **mynodes,
387 void * (*dt_alloc)(u64 size, u64 align))
388 {
389 unsigned long size;
390 int start;
391 void *mem;
392
393 pr_debug(" -> unflatten_device_tree()\n");
394
395 if (!blob) {
396 pr_debug("No device tree pointer\n");
397 return;
398 }
399
400 pr_debug("Unflattening device tree:\n");
401 pr_debug("magic: %08x\n", fdt_magic(blob));
402 pr_debug("size: %08x\n", fdt_totalsize(blob));
403 pr_debug("version: %08x\n", fdt_version(blob));
404
405 if (fdt_check_header(blob)) {
406 pr_err("Invalid device tree blob header\n");
407 return;
408 }
409
410 /* First pass, scan for size */
411 start = 0;
412 size = (unsigned long)unflatten_dt_node(blob, NULL, &start, NULL, NULL, 0, true);
413 size = ALIGN(size, 4);
414
415 pr_debug(" size is %lx, allocating...\n", size);
416
417 /* Allocate memory for the expanded device tree */
418 mem = dt_alloc(size + 4, __alignof__(struct device_node));
419 memset(mem, 0, size);
420
421 *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
422
423 pr_debug(" unflattening %p...\n", mem);
424
425 /* Second pass, do actual unflattening */
426 start = 0;
427 unflatten_dt_node(blob, mem, &start, NULL, mynodes, 0, false);
428 if (be32_to_cpup(mem + size) != 0xdeadbeef)
429 pr_warning("End of tree marker overwritten: %08x\n",
430 be32_to_cpup(mem + size));
431
432 pr_debug(" <- unflatten_device_tree()\n");
433 }
434
kernel_tree_alloc(u64 size,u64 align)435 static void *kernel_tree_alloc(u64 size, u64 align)
436 {
437 return kzalloc(size, GFP_KERNEL);
438 }
439
440 static DEFINE_MUTEX(of_fdt_unflatten_mutex);
441
442 /**
443 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
444 *
445 * unflattens the device-tree passed by the firmware, creating the
446 * tree of struct device_node. It also fills the "name" and "type"
447 * pointers of the nodes so the normal device-tree walking functions
448 * can be used.
449 */
of_fdt_unflatten_tree(const unsigned long * blob,struct device_node ** mynodes)450 void of_fdt_unflatten_tree(const unsigned long *blob,
451 struct device_node **mynodes)
452 {
453 mutex_lock(&of_fdt_unflatten_mutex);
454 __unflatten_device_tree(blob, mynodes, &kernel_tree_alloc);
455 mutex_unlock(&of_fdt_unflatten_mutex);
456 }
457 EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
458
459 /* Everything below here references initial_boot_params directly. */
460 int __initdata dt_root_addr_cells;
461 int __initdata dt_root_size_cells;
462
463 void *initial_boot_params;
464
465 #ifdef CONFIG_OF_EARLY_FLATTREE
466
467 static u32 of_fdt_crc32;
468
469 /**
470 * res_mem_reserve_reg() - reserve all memory described in 'reg' property
471 */
__reserved_mem_reserve_reg(unsigned long node,const char * uname)472 static int __init __reserved_mem_reserve_reg(unsigned long node,
473 const char *uname)
474 {
475 int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
476 phys_addr_t base, size;
477 int len;
478 const __be32 *prop;
479 int nomap, first = 1;
480
481 prop = of_get_flat_dt_prop(node, "reg", &len);
482 if (!prop)
483 return -ENOENT;
484
485 if (len && len % t_len != 0) {
486 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
487 uname);
488 return -EINVAL;
489 }
490
491 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
492
493 while (len >= t_len) {
494 base = dt_mem_next_cell(dt_root_addr_cells, &prop);
495 size = dt_mem_next_cell(dt_root_size_cells, &prop);
496
497 if (size &&
498 early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
499 pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
500 uname, &base, (unsigned long)size / SZ_1M);
501 else
502 pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
503 uname, &base, (unsigned long)size / SZ_1M);
504
505 len -= t_len;
506 if (first) {
507 fdt_reserved_mem_save_node(node, uname, base, size);
508 first = 0;
509 }
510 }
511 return 0;
512 }
513
514 /**
515 * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
516 * in /reserved-memory matches the values supported by the current implementation,
517 * also check if ranges property has been provided
518 */
__reserved_mem_check_root(unsigned long node)519 static int __init __reserved_mem_check_root(unsigned long node)
520 {
521 const __be32 *prop;
522
523 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
524 if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
525 return -EINVAL;
526
527 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
528 if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
529 return -EINVAL;
530
531 prop = of_get_flat_dt_prop(node, "ranges", NULL);
532 if (!prop)
533 return -EINVAL;
534 return 0;
535 }
536
537 /**
538 * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
539 */
__fdt_scan_reserved_mem(unsigned long node,const char * uname,int depth,void * data)540 static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
541 int depth, void *data)
542 {
543 static int found;
544 const char *status;
545 int err;
546
547 if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
548 if (__reserved_mem_check_root(node) != 0) {
549 pr_err("Reserved memory: unsupported node format, ignoring\n");
550 /* break scan */
551 return 1;
552 }
553 found = 1;
554 /* scan next node */
555 return 0;
556 } else if (!found) {
557 /* scan next node */
558 return 0;
559 } else if (found && depth < 2) {
560 /* scanning of /reserved-memory has been finished */
561 return 1;
562 }
563
564 status = of_get_flat_dt_prop(node, "status", NULL);
565 if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0)
566 return 0;
567
568 err = __reserved_mem_reserve_reg(node, uname);
569 if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
570 fdt_reserved_mem_save_node(node, uname, 0, 0);
571
572 /* scan next node */
573 return 0;
574 }
575
576 /**
577 * early_init_fdt_scan_reserved_mem() - create reserved memory regions
578 *
579 * This function grabs memory from early allocator for device exclusive use
580 * defined in device tree structures. It should be called by arch specific code
581 * once the early allocator (i.e. memblock) has been fully activated.
582 */
early_init_fdt_scan_reserved_mem(void)583 void __init early_init_fdt_scan_reserved_mem(void)
584 {
585 int n;
586 u64 base, size;
587
588 if (!initial_boot_params)
589 return;
590
591 /* Process header /memreserve/ fields */
592 for (n = 0; ; n++) {
593 fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
594 if (!size)
595 break;
596 early_init_dt_reserve_memory_arch(base, size, 0);
597 }
598
599 of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
600 fdt_init_reserved_mem();
601 }
602
603 /**
604 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
605 */
early_init_fdt_reserve_self(void)606 void __init early_init_fdt_reserve_self(void)
607 {
608 if (!initial_boot_params)
609 return;
610
611 /* Reserve the dtb region */
612 early_init_dt_reserve_memory_arch(__pa(initial_boot_params),
613 fdt_totalsize(initial_boot_params),
614 0);
615 }
616
617 /**
618 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
619 * @it: callback function
620 * @data: context data pointer
621 *
622 * This function is used to scan the flattened device-tree, it is
623 * used to extract the memory information at boot before we can
624 * unflatten the tree
625 */
of_scan_flat_dt(int (* it)(unsigned long node,const char * uname,int depth,void * data),void * data)626 int __init of_scan_flat_dt(int (*it)(unsigned long node,
627 const char *uname, int depth,
628 void *data),
629 void *data)
630 {
631 const void *blob = initial_boot_params;
632 const char *pathp;
633 int offset, rc = 0, depth = -1;
634
635 if (!blob)
636 return 0;
637
638 for (offset = fdt_next_node(blob, -1, &depth);
639 offset >= 0 && depth >= 0 && !rc;
640 offset = fdt_next_node(blob, offset, &depth)) {
641
642 pathp = fdt_get_name(blob, offset, NULL);
643 if (*pathp == '/')
644 pathp = kbasename(pathp);
645 rc = it(offset, pathp, depth, data);
646 }
647 return rc;
648 }
649
650 /**
651 * of_get_flat_dt_root - find the root node in the flat blob
652 */
of_get_flat_dt_root(void)653 unsigned long __init of_get_flat_dt_root(void)
654 {
655 return 0;
656 }
657
658 /**
659 * of_get_flat_dt_size - Return the total size of the FDT
660 */
of_get_flat_dt_size(void)661 int __init of_get_flat_dt_size(void)
662 {
663 return fdt_totalsize(initial_boot_params);
664 }
665
666 /**
667 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
668 *
669 * This function can be used within scan_flattened_dt callback to get
670 * access to properties
671 */
of_get_flat_dt_prop(unsigned long node,const char * name,int * size)672 const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
673 int *size)
674 {
675 return fdt_getprop(initial_boot_params, node, name, size);
676 }
677
678 /**
679 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
680 * @node: node to test
681 * @compat: compatible string to compare with compatible list.
682 */
of_flat_dt_is_compatible(unsigned long node,const char * compat)683 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
684 {
685 return of_fdt_is_compatible(initial_boot_params, node, compat);
686 }
687
688 /**
689 * of_flat_dt_match - Return true if node matches a list of compatible values
690 */
of_flat_dt_match(unsigned long node,const char * const * compat)691 int __init of_flat_dt_match(unsigned long node, const char *const *compat)
692 {
693 return of_fdt_match(initial_boot_params, node, compat);
694 }
695
696 struct fdt_scan_status {
697 const char *name;
698 int namelen;
699 int depth;
700 int found;
701 int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
702 void *data;
703 };
704
of_flat_dt_get_machine_name(void)705 const char * __init of_flat_dt_get_machine_name(void)
706 {
707 const char *name;
708 unsigned long dt_root = of_get_flat_dt_root();
709
710 name = of_get_flat_dt_prop(dt_root, "model", NULL);
711 if (!name)
712 name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
713 return name;
714 }
715
716 /**
717 * of_flat_dt_match_machine - Iterate match tables to find matching machine.
718 *
719 * @default_match: A machine specific ptr to return in case of no match.
720 * @get_next_compat: callback function to return next compatible match table.
721 *
722 * Iterate through machine match tables to find the best match for the machine
723 * compatible string in the FDT.
724 */
of_flat_dt_match_machine(const void * default_match,const void * (* get_next_compat)(const char * const **))725 const void * __init of_flat_dt_match_machine(const void *default_match,
726 const void * (*get_next_compat)(const char * const**))
727 {
728 const void *data = NULL;
729 const void *best_data = default_match;
730 const char *const *compat;
731 unsigned long dt_root;
732 unsigned int best_score = ~1, score = 0;
733
734 dt_root = of_get_flat_dt_root();
735 while ((data = get_next_compat(&compat))) {
736 score = of_flat_dt_match(dt_root, compat);
737 if (score > 0 && score < best_score) {
738 best_data = data;
739 best_score = score;
740 }
741 }
742 if (!best_data) {
743 const char *prop;
744 int size;
745
746 pr_err("\n unrecognized device tree list:\n[ ");
747
748 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
749 if (prop) {
750 while (size > 0) {
751 printk("'%s' ", prop);
752 size -= strlen(prop) + 1;
753 prop += strlen(prop) + 1;
754 }
755 }
756 printk("]\n\n");
757 return NULL;
758 }
759
760 pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
761
762 return best_data;
763 }
764
765 #ifdef CONFIG_BLK_DEV_INITRD
766 #ifndef __early_init_dt_declare_initrd
__early_init_dt_declare_initrd(unsigned long start,unsigned long end)767 static void __early_init_dt_declare_initrd(unsigned long start,
768 unsigned long end)
769 {
770 initrd_start = (unsigned long)__va(start);
771 initrd_end = (unsigned long)__va(end);
772 initrd_below_start_ok = 1;
773 }
774 #endif
775
776 /**
777 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
778 * @node: reference to node containing initrd location ('chosen')
779 */
early_init_dt_check_for_initrd(unsigned long node)780 static void __init early_init_dt_check_for_initrd(unsigned long node)
781 {
782 u64 start, end;
783 int len;
784 const __be32 *prop;
785
786 pr_debug("Looking for initrd properties... ");
787
788 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
789 if (!prop)
790 return;
791 start = of_read_number(prop, len/4);
792
793 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
794 if (!prop)
795 return;
796 end = of_read_number(prop, len/4);
797
798 __early_init_dt_declare_initrd(start, end);
799
800 pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n",
801 (unsigned long long)start, (unsigned long long)end);
802 }
803 #else
early_init_dt_check_for_initrd(unsigned long node)804 static inline void early_init_dt_check_for_initrd(unsigned long node)
805 {
806 }
807 #endif /* CONFIG_BLK_DEV_INITRD */
808
809 #ifdef CONFIG_SERIAL_EARLYCON
810 extern struct of_device_id __earlycon_of_table[];
811
early_init_dt_scan_chosen_serial(void)812 static int __init early_init_dt_scan_chosen_serial(void)
813 {
814 int offset;
815 const char *p;
816 int l;
817 const struct of_device_id *match = __earlycon_of_table;
818 const void *fdt = initial_boot_params;
819
820 offset = fdt_path_offset(fdt, "/chosen");
821 if (offset < 0)
822 offset = fdt_path_offset(fdt, "/chosen@0");
823 if (offset < 0)
824 return -ENOENT;
825
826 p = fdt_getprop(fdt, offset, "stdout-path", &l);
827 if (!p)
828 p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
829 if (!p || !l)
830 return -ENOENT;
831
832 /* Remove console options if present */
833 l = strchrnul(p, ':') - p;
834
835 /* Get the node specified by stdout-path */
836 offset = fdt_path_offset_namelen(fdt, p, l);
837 if (offset < 0)
838 return -ENODEV;
839
840 while (match->compatible[0]) {
841 u64 addr;
842
843 if (fdt_node_check_compatible(fdt, offset, match->compatible)) {
844 match++;
845 continue;
846 }
847
848 addr = fdt_translate_address(fdt, offset);
849 if (addr == OF_BAD_ADDR)
850 return -ENXIO;
851
852 of_setup_earlycon(addr, match->data);
853 return 0;
854 }
855 return -ENODEV;
856 }
857
setup_of_earlycon(char * buf)858 static int __init setup_of_earlycon(char *buf)
859 {
860 if (buf)
861 return 0;
862
863 return early_init_dt_scan_chosen_serial();
864 }
865 early_param("earlycon", setup_of_earlycon);
866 #endif
867
868 /**
869 * early_init_dt_scan_root - fetch the top level address and size cells
870 */
early_init_dt_scan_root(unsigned long node,const char * uname,int depth,void * data)871 int __init early_init_dt_scan_root(unsigned long node, const char *uname,
872 int depth, void *data)
873 {
874 const __be32 *prop;
875
876 if (depth != 0)
877 return 0;
878
879 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
880 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
881
882 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
883 if (prop)
884 dt_root_size_cells = be32_to_cpup(prop);
885 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
886
887 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
888 if (prop)
889 dt_root_addr_cells = be32_to_cpup(prop);
890 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
891
892 /* break now */
893 return 1;
894 }
895
dt_mem_next_cell(int s,const __be32 ** cellp)896 u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
897 {
898 const __be32 *p = *cellp;
899
900 *cellp = p + s;
901 return of_read_number(p, s);
902 }
903
904 /**
905 * early_init_dt_scan_memory - Look for an parse memory nodes
906 */
early_init_dt_scan_memory(unsigned long node,const char * uname,int depth,void * data)907 int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
908 int depth, void *data)
909 {
910 const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
911 const __be32 *reg, *endp;
912 int l;
913
914 /* We are scanning "memory" nodes only */
915 if (type == NULL) {
916 /*
917 * The longtrail doesn't have a device_type on the
918 * /memory node, so look for the node called /memory@0.
919 */
920 if (!IS_ENABLED(CONFIG_PPC32) || depth != 1 || strcmp(uname, "memory@0") != 0)
921 return 0;
922 } else if (strcmp(type, "memory") != 0)
923 return 0;
924
925 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
926 if (reg == NULL)
927 reg = of_get_flat_dt_prop(node, "reg", &l);
928 if (reg == NULL)
929 return 0;
930
931 endp = reg + (l / sizeof(__be32));
932
933 pr_debug("memory scan node %s, reg size %d,\n", uname, l);
934
935 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
936 u64 base, size;
937
938 base = dt_mem_next_cell(dt_root_addr_cells, ®);
939 size = dt_mem_next_cell(dt_root_size_cells, ®);
940
941 if (size == 0)
942 continue;
943 pr_debug(" - %llx , %llx\n", (unsigned long long)base,
944 (unsigned long long)size);
945
946 early_init_dt_add_memory_arch(base, size);
947 }
948
949 return 0;
950 }
951
952 /*
953 * Convert configs to something easy to use in C code
954 */
955 #if defined(CONFIG_CMDLINE_FORCE)
956 static const int overwrite_incoming_cmdline = 1;
957 static const int read_dt_cmdline;
958 static const int concat_cmdline;
959 #elif defined(CONFIG_CMDLINE_EXTEND)
960 static const int overwrite_incoming_cmdline;
961 static const int read_dt_cmdline = 1;
962 static const int concat_cmdline = 1;
963 #else /* CMDLINE_FROM_BOOTLOADER */
964 static const int overwrite_incoming_cmdline;
965 static const int read_dt_cmdline = 1;
966 static const int concat_cmdline;
967 #endif
968
969 #ifdef CONFIG_CMDLINE
970 static const char *config_cmdline = CONFIG_CMDLINE;
971 #else
972 static const char *config_cmdline = "";
973 #endif
974
early_init_dt_scan_chosen(unsigned long node,const char * uname,int depth,void * data)975 int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
976 int depth, void *data)
977 {
978 int l = 0;
979 const char *p = NULL;
980 char *cmdline = data;
981
982 pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
983
984 if (depth != 1 || !cmdline ||
985 (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
986 return 0;
987
988 early_init_dt_check_for_initrd(node);
989
990 /* Put CONFIG_CMDLINE in if forced or if data had nothing in it to start */
991 if (overwrite_incoming_cmdline || !cmdline[0])
992 strlcpy(cmdline, config_cmdline, COMMAND_LINE_SIZE);
993
994 /* Retrieve command line unless forcing */
995 if (read_dt_cmdline)
996 p = of_get_flat_dt_prop(node, "bootargs", &l);
997
998 if (p != NULL && l > 0) {
999 if (concat_cmdline) {
1000 int cmdline_len;
1001 int copy_len;
1002 strlcat(cmdline, " ", COMMAND_LINE_SIZE);
1003 cmdline_len = strlen(cmdline);
1004 copy_len = COMMAND_LINE_SIZE - cmdline_len - 1;
1005 copy_len = min((int)l, copy_len);
1006 strncpy(cmdline + cmdline_len, p, copy_len);
1007 cmdline[cmdline_len + copy_len] = '\0';
1008 } else {
1009 strlcpy(cmdline, p, min((int)l, COMMAND_LINE_SIZE));
1010 }
1011 }
1012
1013 pr_debug("Command line is: %s\n", (char*)data);
1014
1015 /* break now */
1016 return 1;
1017 }
1018
1019 #ifdef CONFIG_HAVE_MEMBLOCK
1020 #ifndef MIN_MEMBLOCK_ADDR
1021 #define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET)
1022 #endif
1023 #ifndef MAX_MEMBLOCK_ADDR
1024 #define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0)
1025 #endif
1026
early_init_dt_add_memory_arch(u64 base,u64 size)1027 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1028 {
1029 const u64 phys_offset = MIN_MEMBLOCK_ADDR;
1030
1031 if (!PAGE_ALIGNED(base)) {
1032 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
1033 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1034 base, base + size);
1035 return;
1036 }
1037 size -= PAGE_SIZE - (base & ~PAGE_MASK);
1038 base = PAGE_ALIGN(base);
1039 }
1040 size &= PAGE_MASK;
1041
1042 if (base > MAX_MEMBLOCK_ADDR) {
1043 pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
1044 base, base + size);
1045 return;
1046 }
1047
1048 if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
1049 pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
1050 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
1051 size = MAX_MEMBLOCK_ADDR - base + 1;
1052 }
1053
1054 if (base + size < phys_offset) {
1055 pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
1056 base, base + size);
1057 return;
1058 }
1059 if (base < phys_offset) {
1060 pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
1061 base, phys_offset);
1062 size -= phys_offset - base;
1063 base = phys_offset;
1064 }
1065 memblock_add(base, size);
1066 }
1067
early_init_dt_reserve_memory_arch(phys_addr_t base,phys_addr_t size,bool nomap)1068 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
1069 phys_addr_t size, bool nomap)
1070 {
1071 if (nomap)
1072 return memblock_remove(base, size);
1073 return memblock_reserve(base, size);
1074 }
1075
1076 /*
1077 * called from unflatten_device_tree() to bootstrap devicetree itself
1078 * Architectures can override this definition if memblock isn't used
1079 */
early_init_dt_alloc_memory_arch(u64 size,u64 align)1080 void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
1081 {
1082 return __va(memblock_alloc(size, align));
1083 }
1084 #else
early_init_dt_add_memory_arch(u64 base,u64 size)1085 void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1086 {
1087 WARN_ON(1);
1088 }
1089
early_init_dt_reserve_memory_arch(phys_addr_t base,phys_addr_t size,bool nomap)1090 int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
1091 phys_addr_t size, bool nomap)
1092 {
1093 pr_err("Reserved memory not supported, ignoring range %pa - %pa%s\n",
1094 &base, &size, nomap ? " (nomap)" : "");
1095 return -ENOSYS;
1096 }
1097
early_init_dt_alloc_memory_arch(u64 size,u64 align)1098 void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
1099 {
1100 WARN_ON(1);
1101 return NULL;
1102 }
1103 #endif
1104
early_init_dt_verify(void * params)1105 bool __init early_init_dt_verify(void *params)
1106 {
1107 if (!params)
1108 return false;
1109
1110 /* check device tree validity */
1111 if (fdt_check_header(params))
1112 return false;
1113
1114 /* Setup flat device-tree pointer */
1115 initial_boot_params = params;
1116 of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1117 fdt_totalsize(initial_boot_params));
1118 return true;
1119 }
1120
1121
early_init_dt_scan_nodes(void)1122 void __init early_init_dt_scan_nodes(void)
1123 {
1124 /* Retrieve various information from the /chosen node */
1125 of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
1126
1127 /* Initialize {size,address}-cells info */
1128 of_scan_flat_dt(early_init_dt_scan_root, NULL);
1129
1130 /* Setup memory, calling early_init_dt_add_memory_arch */
1131 of_scan_flat_dt(early_init_dt_scan_memory, NULL);
1132 }
1133
early_init_dt_scan(void * params)1134 bool __init early_init_dt_scan(void *params)
1135 {
1136 bool status;
1137
1138 status = early_init_dt_verify(params);
1139 if (!status)
1140 return false;
1141
1142 early_init_dt_scan_nodes();
1143 return true;
1144 }
1145
1146 /**
1147 * unflatten_device_tree - create tree of device_nodes from flat blob
1148 *
1149 * unflattens the device-tree passed by the firmware, creating the
1150 * tree of struct device_node. It also fills the "name" and "type"
1151 * pointers of the nodes so the normal device-tree walking functions
1152 * can be used.
1153 */
unflatten_device_tree(void)1154 void __init unflatten_device_tree(void)
1155 {
1156 __unflatten_device_tree(initial_boot_params, &of_root,
1157 early_init_dt_alloc_memory_arch);
1158
1159 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1160 of_alias_scan(early_init_dt_alloc_memory_arch);
1161 }
1162
1163 /**
1164 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1165 *
1166 * Copies and unflattens the device-tree passed by the firmware, creating the
1167 * tree of struct device_node. It also fills the "name" and "type"
1168 * pointers of the nodes so the normal device-tree walking functions
1169 * can be used. This should only be used when the FDT memory has not been
1170 * reserved such is the case when the FDT is built-in to the kernel init
1171 * section. If the FDT memory is reserved already then unflatten_device_tree
1172 * should be used instead.
1173 */
unflatten_and_copy_device_tree(void)1174 void __init unflatten_and_copy_device_tree(void)
1175 {
1176 int size;
1177 void *dt;
1178
1179 if (!initial_boot_params) {
1180 pr_warn("No valid device tree found, continuing without\n");
1181 return;
1182 }
1183
1184 size = fdt_totalsize(initial_boot_params);
1185 dt = early_init_dt_alloc_memory_arch(size,
1186 roundup_pow_of_two(FDT_V17_SIZE));
1187
1188 if (dt) {
1189 memcpy(dt, initial_boot_params, size);
1190 initial_boot_params = dt;
1191 }
1192 unflatten_device_tree();
1193 }
1194
1195 #ifdef CONFIG_SYSFS
of_fdt_raw_read(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)1196 static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
1197 struct bin_attribute *bin_attr,
1198 char *buf, loff_t off, size_t count)
1199 {
1200 memcpy(buf, initial_boot_params + off, count);
1201 return count;
1202 }
1203
of_fdt_raw_init(void)1204 static int __init of_fdt_raw_init(void)
1205 {
1206 static struct bin_attribute of_fdt_raw_attr =
1207 __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
1208
1209 if (!initial_boot_params)
1210 return 0;
1211
1212 if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
1213 fdt_totalsize(initial_boot_params))) {
1214 pr_warn("fdt: not creating '/sys/firmware/fdt': CRC check failed\n");
1215 return 0;
1216 }
1217 of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
1218 return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
1219 }
1220 late_initcall(of_fdt_raw_init);
1221 #endif
1222
1223 #endif /* CONFIG_OF_EARLY_FLATTREE */
1224