xref: /openbmc/linux/arch/powerpc/kernel/prom.c (revision b627b4ed)
1 /*
2  * Procedures for creating, accessing and interpreting the device tree.
3  *
4  * Paul Mackerras	August 1996.
5  * Copyright (C) 1996-2005 Paul Mackerras.
6  *
7  *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
8  *    {engebret|bergner}@us.ibm.com
9  *
10  *      This program is free software; you can redistribute it and/or
11  *      modify it under the terms of the GNU General Public License
12  *      as published by the Free Software Foundation; either version
13  *      2 of the License, or (at your option) any later version.
14  */
15 
16 #undef DEBUG
17 
18 #include <stdarg.h>
19 #include <linux/kernel.h>
20 #include <linux/string.h>
21 #include <linux/init.h>
22 #include <linux/threads.h>
23 #include <linux/spinlock.h>
24 #include <linux/types.h>
25 #include <linux/pci.h>
26 #include <linux/stringify.h>
27 #include <linux/delay.h>
28 #include <linux/initrd.h>
29 #include <linux/bitops.h>
30 #include <linux/module.h>
31 #include <linux/kexec.h>
32 #include <linux/debugfs.h>
33 #include <linux/irq.h>
34 #include <linux/lmb.h>
35 
36 #include <asm/prom.h>
37 #include <asm/rtas.h>
38 #include <asm/page.h>
39 #include <asm/processor.h>
40 #include <asm/irq.h>
41 #include <asm/io.h>
42 #include <asm/kdump.h>
43 #include <asm/smp.h>
44 #include <asm/system.h>
45 #include <asm/mmu.h>
46 #include <asm/pgtable.h>
47 #include <asm/pci.h>
48 #include <asm/iommu.h>
49 #include <asm/btext.h>
50 #include <asm/sections.h>
51 #include <asm/machdep.h>
52 #include <asm/pSeries_reconfig.h>
53 #include <asm/pci-bridge.h>
54 #include <asm/phyp_dump.h>
55 #include <asm/kexec.h>
56 #include <mm/mmu_decl.h>
57 
58 #ifdef DEBUG
59 #define DBG(fmt...) printk(KERN_ERR fmt)
60 #else
61 #define DBG(fmt...)
62 #endif
63 
64 
65 static int __initdata dt_root_addr_cells;
66 static int __initdata dt_root_size_cells;
67 
68 #ifdef CONFIG_PPC64
69 int __initdata iommu_is_off;
70 int __initdata iommu_force_on;
71 unsigned long tce_alloc_start, tce_alloc_end;
72 #endif
73 
74 typedef u32 cell_t;
75 
76 #if 0
77 static struct boot_param_header *initial_boot_params __initdata;
78 #else
79 struct boot_param_header *initial_boot_params;
80 #endif
81 
82 extern struct device_node *allnodes;	/* temporary while merging */
83 
84 extern rwlock_t devtree_lock;	/* temporary while merging */
85 
86 /* export that to outside world */
87 struct device_node *of_chosen;
88 
89 static inline char *find_flat_dt_string(u32 offset)
90 {
91 	return ((char *)initial_boot_params) +
92 		initial_boot_params->off_dt_strings + offset;
93 }
94 
95 /**
96  * This function is used to scan the flattened device-tree, it is
97  * used to extract the memory informations at boot before we can
98  * unflatten the tree
99  */
100 int __init of_scan_flat_dt(int (*it)(unsigned long node,
101 				     const char *uname, int depth,
102 				     void *data),
103 			   void *data)
104 {
105 	unsigned long p = ((unsigned long)initial_boot_params) +
106 		initial_boot_params->off_dt_struct;
107 	int rc = 0;
108 	int depth = -1;
109 
110 	do {
111 		u32 tag = *((u32 *)p);
112 		char *pathp;
113 
114 		p += 4;
115 		if (tag == OF_DT_END_NODE) {
116 			depth --;
117 			continue;
118 		}
119 		if (tag == OF_DT_NOP)
120 			continue;
121 		if (tag == OF_DT_END)
122 			break;
123 		if (tag == OF_DT_PROP) {
124 			u32 sz = *((u32 *)p);
125 			p += 8;
126 			if (initial_boot_params->version < 0x10)
127 				p = _ALIGN(p, sz >= 8 ? 8 : 4);
128 			p += sz;
129 			p = _ALIGN(p, 4);
130 			continue;
131 		}
132 		if (tag != OF_DT_BEGIN_NODE) {
133 			printk(KERN_WARNING "Invalid tag %x scanning flattened"
134 			       " device tree !\n", tag);
135 			return -EINVAL;
136 		}
137 		depth++;
138 		pathp = (char *)p;
139 		p = _ALIGN(p + strlen(pathp) + 1, 4);
140 		if ((*pathp) == '/') {
141 			char *lp, *np;
142 			for (lp = NULL, np = pathp; *np; np++)
143 				if ((*np) == '/')
144 					lp = np+1;
145 			if (lp != NULL)
146 				pathp = lp;
147 		}
148 		rc = it(p, pathp, depth, data);
149 		if (rc != 0)
150 			break;
151 	} while(1);
152 
153 	return rc;
154 }
155 
156 unsigned long __init of_get_flat_dt_root(void)
157 {
158 	unsigned long p = ((unsigned long)initial_boot_params) +
159 		initial_boot_params->off_dt_struct;
160 
161 	while(*((u32 *)p) == OF_DT_NOP)
162 		p += 4;
163 	BUG_ON (*((u32 *)p) != OF_DT_BEGIN_NODE);
164 	p += 4;
165 	return _ALIGN(p + strlen((char *)p) + 1, 4);
166 }
167 
168 /**
169  * This  function can be used within scan_flattened_dt callback to get
170  * access to properties
171  */
172 void* __init of_get_flat_dt_prop(unsigned long node, const char *name,
173 				 unsigned long *size)
174 {
175 	unsigned long p = node;
176 
177 	do {
178 		u32 tag = *((u32 *)p);
179 		u32 sz, noff;
180 		const char *nstr;
181 
182 		p += 4;
183 		if (tag == OF_DT_NOP)
184 			continue;
185 		if (tag != OF_DT_PROP)
186 			return NULL;
187 
188 		sz = *((u32 *)p);
189 		noff = *((u32 *)(p + 4));
190 		p += 8;
191 		if (initial_boot_params->version < 0x10)
192 			p = _ALIGN(p, sz >= 8 ? 8 : 4);
193 
194 		nstr = find_flat_dt_string(noff);
195 		if (nstr == NULL) {
196 			printk(KERN_WARNING "Can't find property index"
197 			       " name !\n");
198 			return NULL;
199 		}
200 		if (strcmp(name, nstr) == 0) {
201 			if (size)
202 				*size = sz;
203 			return (void *)p;
204 		}
205 		p += sz;
206 		p = _ALIGN(p, 4);
207 	} while(1);
208 }
209 
210 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
211 {
212 	const char* cp;
213 	unsigned long cplen, l;
214 
215 	cp = of_get_flat_dt_prop(node, "compatible", &cplen);
216 	if (cp == NULL)
217 		return 0;
218 	while (cplen > 0) {
219 		if (strncasecmp(cp, compat, strlen(compat)) == 0)
220 			return 1;
221 		l = strlen(cp) + 1;
222 		cp += l;
223 		cplen -= l;
224 	}
225 
226 	return 0;
227 }
228 
229 static void *__init unflatten_dt_alloc(unsigned long *mem, unsigned long size,
230 				       unsigned long align)
231 {
232 	void *res;
233 
234 	*mem = _ALIGN(*mem, align);
235 	res = (void *)*mem;
236 	*mem += size;
237 
238 	return res;
239 }
240 
241 static unsigned long __init unflatten_dt_node(unsigned long mem,
242 					      unsigned long *p,
243 					      struct device_node *dad,
244 					      struct device_node ***allnextpp,
245 					      unsigned long fpsize)
246 {
247 	struct device_node *np;
248 	struct property *pp, **prev_pp = NULL;
249 	char *pathp;
250 	u32 tag;
251 	unsigned int l, allocl;
252 	int has_name = 0;
253 	int new_format = 0;
254 
255 	tag = *((u32 *)(*p));
256 	if (tag != OF_DT_BEGIN_NODE) {
257 		printk("Weird tag at start of node: %x\n", tag);
258 		return mem;
259 	}
260 	*p += 4;
261 	pathp = (char *)*p;
262 	l = allocl = strlen(pathp) + 1;
263 	*p = _ALIGN(*p + l, 4);
264 
265 	/* version 0x10 has a more compact unit name here instead of the full
266 	 * path. we accumulate the full path size using "fpsize", we'll rebuild
267 	 * it later. We detect this because the first character of the name is
268 	 * not '/'.
269 	 */
270 	if ((*pathp) != '/') {
271 		new_format = 1;
272 		if (fpsize == 0) {
273 			/* root node: special case. fpsize accounts for path
274 			 * plus terminating zero. root node only has '/', so
275 			 * fpsize should be 2, but we want to avoid the first
276 			 * level nodes to have two '/' so we use fpsize 1 here
277 			 */
278 			fpsize = 1;
279 			allocl = 2;
280 		} else {
281 			/* account for '/' and path size minus terminal 0
282 			 * already in 'l'
283 			 */
284 			fpsize += l;
285 			allocl = fpsize;
286 		}
287 	}
288 
289 
290 	np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
291 				__alignof__(struct device_node));
292 	if (allnextpp) {
293 		memset(np, 0, sizeof(*np));
294 		np->full_name = ((char*)np) + sizeof(struct device_node);
295 		if (new_format) {
296 			char *p = np->full_name;
297 			/* rebuild full path for new format */
298 			if (dad && dad->parent) {
299 				strcpy(p, dad->full_name);
300 #ifdef DEBUG
301 				if ((strlen(p) + l + 1) != allocl) {
302 					DBG("%s: p: %d, l: %d, a: %d\n",
303 					    pathp, (int)strlen(p), l, allocl);
304 				}
305 #endif
306 				p += strlen(p);
307 			}
308 			*(p++) = '/';
309 			memcpy(p, pathp, l);
310 		} else
311 			memcpy(np->full_name, pathp, l);
312 		prev_pp = &np->properties;
313 		**allnextpp = np;
314 		*allnextpp = &np->allnext;
315 		if (dad != NULL) {
316 			np->parent = dad;
317 			/* we temporarily use the next field as `last_child'*/
318 			if (dad->next == 0)
319 				dad->child = np;
320 			else
321 				dad->next->sibling = np;
322 			dad->next = np;
323 		}
324 		kref_init(&np->kref);
325 	}
326 	while(1) {
327 		u32 sz, noff;
328 		char *pname;
329 
330 		tag = *((u32 *)(*p));
331 		if (tag == OF_DT_NOP) {
332 			*p += 4;
333 			continue;
334 		}
335 		if (tag != OF_DT_PROP)
336 			break;
337 		*p += 4;
338 		sz = *((u32 *)(*p));
339 		noff = *((u32 *)((*p) + 4));
340 		*p += 8;
341 		if (initial_boot_params->version < 0x10)
342 			*p = _ALIGN(*p, sz >= 8 ? 8 : 4);
343 
344 		pname = find_flat_dt_string(noff);
345 		if (pname == NULL) {
346 			printk("Can't find property name in list !\n");
347 			break;
348 		}
349 		if (strcmp(pname, "name") == 0)
350 			has_name = 1;
351 		l = strlen(pname) + 1;
352 		pp = unflatten_dt_alloc(&mem, sizeof(struct property),
353 					__alignof__(struct property));
354 		if (allnextpp) {
355 			if (strcmp(pname, "linux,phandle") == 0) {
356 				np->node = *((u32 *)*p);
357 				if (np->linux_phandle == 0)
358 					np->linux_phandle = np->node;
359 			}
360 			if (strcmp(pname, "ibm,phandle") == 0)
361 				np->linux_phandle = *((u32 *)*p);
362 			pp->name = pname;
363 			pp->length = sz;
364 			pp->value = (void *)*p;
365 			*prev_pp = pp;
366 			prev_pp = &pp->next;
367 		}
368 		*p = _ALIGN((*p) + sz, 4);
369 	}
370 	/* with version 0x10 we may not have the name property, recreate
371 	 * it here from the unit name if absent
372 	 */
373 	if (!has_name) {
374 		char *p = pathp, *ps = pathp, *pa = NULL;
375 		int sz;
376 
377 		while (*p) {
378 			if ((*p) == '@')
379 				pa = p;
380 			if ((*p) == '/')
381 				ps = p + 1;
382 			p++;
383 		}
384 		if (pa < ps)
385 			pa = p;
386 		sz = (pa - ps) + 1;
387 		pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
388 					__alignof__(struct property));
389 		if (allnextpp) {
390 			pp->name = "name";
391 			pp->length = sz;
392 			pp->value = pp + 1;
393 			*prev_pp = pp;
394 			prev_pp = &pp->next;
395 			memcpy(pp->value, ps, sz - 1);
396 			((char *)pp->value)[sz - 1] = 0;
397 			DBG("fixed up name for %s -> %s\n", pathp,
398 				(char *)pp->value);
399 		}
400 	}
401 	if (allnextpp) {
402 		*prev_pp = NULL;
403 		np->name = of_get_property(np, "name", NULL);
404 		np->type = of_get_property(np, "device_type", NULL);
405 
406 		if (!np->name)
407 			np->name = "<NULL>";
408 		if (!np->type)
409 			np->type = "<NULL>";
410 	}
411 	while (tag == OF_DT_BEGIN_NODE) {
412 		mem = unflatten_dt_node(mem, p, np, allnextpp, fpsize);
413 		tag = *((u32 *)(*p));
414 	}
415 	if (tag != OF_DT_END_NODE) {
416 		printk("Weird tag at end of node: %x\n", tag);
417 		return mem;
418 	}
419 	*p += 4;
420 	return mem;
421 }
422 
423 static int __init early_parse_mem(char *p)
424 {
425 	if (!p)
426 		return 1;
427 
428 	memory_limit = PAGE_ALIGN(memparse(p, &p));
429 	DBG("memory limit = 0x%lx\n", memory_limit);
430 
431 	return 0;
432 }
433 early_param("mem", early_parse_mem);
434 
435 /**
436  * move_device_tree - move tree to an unused area, if needed.
437  *
438  * The device tree may be allocated beyond our memory limit, or inside the
439  * crash kernel region for kdump. If so, move it out of the way.
440  */
441 static void __init move_device_tree(void)
442 {
443 	unsigned long start, size;
444 	void *p;
445 
446 	DBG("-> move_device_tree\n");
447 
448 	start = __pa(initial_boot_params);
449 	size = initial_boot_params->totalsize;
450 
451 	if ((memory_limit && (start + size) > memory_limit) ||
452 			overlaps_crashkernel(start, size)) {
453 		p = __va(lmb_alloc_base(size, PAGE_SIZE, lmb.rmo_size));
454 		memcpy(p, initial_boot_params, size);
455 		initial_boot_params = (struct boot_param_header *)p;
456 		DBG("Moved device tree to 0x%p\n", p);
457 	}
458 
459 	DBG("<- move_device_tree\n");
460 }
461 
462 /**
463  * unflattens the device-tree passed by the firmware, creating the
464  * tree of struct device_node. It also fills the "name" and "type"
465  * pointers of the nodes so the normal device-tree walking functions
466  * can be used (this used to be done by finish_device_tree)
467  */
468 void __init unflatten_device_tree(void)
469 {
470 	unsigned long start, mem, size;
471 	struct device_node **allnextp = &allnodes;
472 
473 	DBG(" -> unflatten_device_tree()\n");
474 
475 	/* First pass, scan for size */
476 	start = ((unsigned long)initial_boot_params) +
477 		initial_boot_params->off_dt_struct;
478 	size = unflatten_dt_node(0, &start, NULL, NULL, 0);
479 	size = (size | 3) + 1;
480 
481 	DBG("  size is %lx, allocating...\n", size);
482 
483 	/* Allocate memory for the expanded device tree */
484 	mem = lmb_alloc(size + 4, __alignof__(struct device_node));
485 	mem = (unsigned long) __va(mem);
486 
487 	((u32 *)mem)[size / 4] = 0xdeadbeef;
488 
489 	DBG("  unflattening %lx...\n", mem);
490 
491 	/* Second pass, do actual unflattening */
492 	start = ((unsigned long)initial_boot_params) +
493 		initial_boot_params->off_dt_struct;
494 	unflatten_dt_node(mem, &start, NULL, &allnextp, 0);
495 	if (*((u32 *)start) != OF_DT_END)
496 		printk(KERN_WARNING "Weird tag at end of tree: %08x\n", *((u32 *)start));
497 	if (((u32 *)mem)[size / 4] != 0xdeadbeef)
498 		printk(KERN_WARNING "End of tree marker overwritten: %08x\n",
499 		       ((u32 *)mem)[size / 4] );
500 	*allnextp = NULL;
501 
502 	/* Get pointer to OF "/chosen" node for use everywhere */
503 	of_chosen = of_find_node_by_path("/chosen");
504 	if (of_chosen == NULL)
505 		of_chosen = of_find_node_by_path("/chosen@0");
506 
507 	DBG(" <- unflatten_device_tree()\n");
508 }
509 
510 /*
511  * ibm,pa-features is a per-cpu property that contains a string of
512  * attribute descriptors, each of which has a 2 byte header plus up
513  * to 254 bytes worth of processor attribute bits.  First header
514  * byte specifies the number of bytes following the header.
515  * Second header byte is an "attribute-specifier" type, of which
516  * zero is the only currently-defined value.
517  * Implementation:  Pass in the byte and bit offset for the feature
518  * that we are interested in.  The function will return -1 if the
519  * pa-features property is missing, or a 1/0 to indicate if the feature
520  * is supported/not supported.  Note that the bit numbers are
521  * big-endian to match the definition in PAPR.
522  */
523 static struct ibm_pa_feature {
524 	unsigned long	cpu_features;	/* CPU_FTR_xxx bit */
525 	unsigned int	cpu_user_ftrs;	/* PPC_FEATURE_xxx bit */
526 	unsigned char	pabyte;		/* byte number in ibm,pa-features */
527 	unsigned char	pabit;		/* bit number (big-endian) */
528 	unsigned char	invert;		/* if 1, pa bit set => clear feature */
529 } ibm_pa_features[] __initdata = {
530 	{0, PPC_FEATURE_HAS_MMU,	0, 0, 0},
531 	{0, PPC_FEATURE_HAS_FPU,	0, 1, 0},
532 	{CPU_FTR_SLB, 0,		0, 2, 0},
533 	{CPU_FTR_CTRL, 0,		0, 3, 0},
534 	{CPU_FTR_NOEXECUTE, 0,		0, 6, 0},
535 	{CPU_FTR_NODSISRALIGN, 0,	1, 1, 1},
536 	{CPU_FTR_CI_LARGE_PAGE, 0,	1, 2, 0},
537 	{CPU_FTR_REAL_LE, PPC_FEATURE_TRUE_LE, 5, 0, 0},
538 };
539 
540 static void __init scan_features(unsigned long node, unsigned char *ftrs,
541 				 unsigned long tablelen,
542 				 struct ibm_pa_feature *fp,
543 				 unsigned long ft_size)
544 {
545 	unsigned long i, len, bit;
546 
547 	/* find descriptor with type == 0 */
548 	for (;;) {
549 		if (tablelen < 3)
550 			return;
551 		len = 2 + ftrs[0];
552 		if (tablelen < len)
553 			return;		/* descriptor 0 not found */
554 		if (ftrs[1] == 0)
555 			break;
556 		tablelen -= len;
557 		ftrs += len;
558 	}
559 
560 	/* loop over bits we know about */
561 	for (i = 0; i < ft_size; ++i, ++fp) {
562 		if (fp->pabyte >= ftrs[0])
563 			continue;
564 		bit = (ftrs[2 + fp->pabyte] >> (7 - fp->pabit)) & 1;
565 		if (bit ^ fp->invert) {
566 			cur_cpu_spec->cpu_features |= fp->cpu_features;
567 			cur_cpu_spec->cpu_user_features |= fp->cpu_user_ftrs;
568 		} else {
569 			cur_cpu_spec->cpu_features &= ~fp->cpu_features;
570 			cur_cpu_spec->cpu_user_features &= ~fp->cpu_user_ftrs;
571 		}
572 	}
573 }
574 
575 static void __init check_cpu_pa_features(unsigned long node)
576 {
577 	unsigned char *pa_ftrs;
578 	unsigned long tablelen;
579 
580 	pa_ftrs = of_get_flat_dt_prop(node, "ibm,pa-features", &tablelen);
581 	if (pa_ftrs == NULL)
582 		return;
583 
584 	scan_features(node, pa_ftrs, tablelen,
585 		      ibm_pa_features, ARRAY_SIZE(ibm_pa_features));
586 }
587 
588 #ifdef CONFIG_PPC64
589 static void __init check_cpu_slb_size(unsigned long node)
590 {
591 	u32 *slb_size_ptr;
592 
593 	slb_size_ptr = of_get_flat_dt_prop(node, "slb-size", NULL);
594 	if (slb_size_ptr != NULL) {
595 		mmu_slb_size = *slb_size_ptr;
596 		return;
597 	}
598 	slb_size_ptr = of_get_flat_dt_prop(node, "ibm,slb-size", NULL);
599 	if (slb_size_ptr != NULL) {
600 		mmu_slb_size = *slb_size_ptr;
601 	}
602 }
603 #else
604 #define check_cpu_slb_size(node) do { } while(0)
605 #endif
606 
607 static struct feature_property {
608 	const char *name;
609 	u32 min_value;
610 	unsigned long cpu_feature;
611 	unsigned long cpu_user_ftr;
612 } feature_properties[] __initdata = {
613 #ifdef CONFIG_ALTIVEC
614 	{"altivec", 0, CPU_FTR_ALTIVEC, PPC_FEATURE_HAS_ALTIVEC},
615 	{"ibm,vmx", 1, CPU_FTR_ALTIVEC, PPC_FEATURE_HAS_ALTIVEC},
616 #endif /* CONFIG_ALTIVEC */
617 #ifdef CONFIG_VSX
618 	/* Yes, this _really_ is ibm,vmx == 2 to enable VSX */
619 	{"ibm,vmx", 2, CPU_FTR_VSX, PPC_FEATURE_HAS_VSX},
620 #endif /* CONFIG_VSX */
621 #ifdef CONFIG_PPC64
622 	{"ibm,dfp", 1, 0, PPC_FEATURE_HAS_DFP},
623 	{"ibm,purr", 1, CPU_FTR_PURR, 0},
624 	{"ibm,spurr", 1, CPU_FTR_SPURR, 0},
625 #endif /* CONFIG_PPC64 */
626 };
627 
628 #if defined(CONFIG_44x) && defined(CONFIG_PPC_FPU)
629 static inline void identical_pvr_fixup(unsigned long node)
630 {
631 	unsigned int pvr;
632 	char *model = of_get_flat_dt_prop(node, "model", NULL);
633 
634 	/*
635 	 * Since 440GR(x)/440EP(x) processors have the same pvr,
636 	 * we check the node path and set bit 28 in the cur_cpu_spec
637 	 * pvr for EP(x) processor version. This bit is always 0 in
638 	 * the "real" pvr. Then we call identify_cpu again with
639 	 * the new logical pvr to enable FPU support.
640 	 */
641 	if (model && strstr(model, "440EP")) {
642 		pvr = cur_cpu_spec->pvr_value | 0x8;
643 		identify_cpu(0, pvr);
644 		DBG("Using logical pvr %x for %s\n", pvr, model);
645 	}
646 }
647 #else
648 #define identical_pvr_fixup(node) do { } while(0)
649 #endif
650 
651 static void __init check_cpu_feature_properties(unsigned long node)
652 {
653 	unsigned long i;
654 	struct feature_property *fp = feature_properties;
655 	const u32 *prop;
656 
657 	for (i = 0; i < ARRAY_SIZE(feature_properties); ++i, ++fp) {
658 		prop = of_get_flat_dt_prop(node, fp->name, NULL);
659 		if (prop && *prop >= fp->min_value) {
660 			cur_cpu_spec->cpu_features |= fp->cpu_feature;
661 			cur_cpu_spec->cpu_user_features |= fp->cpu_user_ftr;
662 		}
663 	}
664 }
665 
666 static int __init early_init_dt_scan_cpus(unsigned long node,
667 					  const char *uname, int depth,
668 					  void *data)
669 {
670 	static int logical_cpuid = 0;
671 	char *type = of_get_flat_dt_prop(node, "device_type", NULL);
672 	const u32 *prop;
673 	const u32 *intserv;
674 	int i, nthreads;
675 	unsigned long len;
676 	int found = 0;
677 
678 	/* We are scanning "cpu" nodes only */
679 	if (type == NULL || strcmp(type, "cpu") != 0)
680 		return 0;
681 
682 	/* Get physical cpuid */
683 	intserv = of_get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s", &len);
684 	if (intserv) {
685 		nthreads = len / sizeof(int);
686 	} else {
687 		intserv = of_get_flat_dt_prop(node, "reg", NULL);
688 		nthreads = 1;
689 	}
690 
691 	/*
692 	 * Now see if any of these threads match our boot cpu.
693 	 * NOTE: This must match the parsing done in smp_setup_cpu_maps.
694 	 */
695 	for (i = 0; i < nthreads; i++) {
696 		/*
697 		 * version 2 of the kexec param format adds the phys cpuid of
698 		 * booted proc.
699 		 */
700 		if (initial_boot_params && initial_boot_params->version >= 2) {
701 			if (intserv[i] ==
702 					initial_boot_params->boot_cpuid_phys) {
703 				found = 1;
704 				break;
705 			}
706 		} else {
707 			/*
708 			 * Check if it's the boot-cpu, set it's hw index now,
709 			 * unfortunately this format did not support booting
710 			 * off secondary threads.
711 			 */
712 			if (of_get_flat_dt_prop(node,
713 					"linux,boot-cpu", NULL) != NULL) {
714 				found = 1;
715 				break;
716 			}
717 		}
718 
719 #ifdef CONFIG_SMP
720 		/* logical cpu id is always 0 on UP kernels */
721 		logical_cpuid++;
722 #endif
723 	}
724 
725 	if (found) {
726 		DBG("boot cpu: logical %d physical %d\n", logical_cpuid,
727 			intserv[i]);
728 		boot_cpuid = logical_cpuid;
729 		set_hard_smp_processor_id(boot_cpuid, intserv[i]);
730 
731 		/*
732 		 * PAPR defines "logical" PVR values for cpus that
733 		 * meet various levels of the architecture:
734 		 * 0x0f000001	Architecture version 2.04
735 		 * 0x0f000002	Architecture version 2.05
736 		 * If the cpu-version property in the cpu node contains
737 		 * such a value, we call identify_cpu again with the
738 		 * logical PVR value in order to use the cpu feature
739 		 * bits appropriate for the architecture level.
740 		 *
741 		 * A POWER6 partition in "POWER6 architected" mode
742 		 * uses the 0x0f000002 PVR value; in POWER5+ mode
743 		 * it uses 0x0f000001.
744 		 */
745 		prop = of_get_flat_dt_prop(node, "cpu-version", NULL);
746 		if (prop && (*prop & 0xff000000) == 0x0f000000)
747 			identify_cpu(0, *prop);
748 
749 		identical_pvr_fixup(node);
750 	}
751 
752 	check_cpu_feature_properties(node);
753 	check_cpu_pa_features(node);
754 	check_cpu_slb_size(node);
755 
756 #ifdef CONFIG_PPC_PSERIES
757 	if (nthreads > 1)
758 		cur_cpu_spec->cpu_features |= CPU_FTR_SMT;
759 	else
760 		cur_cpu_spec->cpu_features &= ~CPU_FTR_SMT;
761 #endif
762 
763 	return 0;
764 }
765 
766 #ifdef CONFIG_BLK_DEV_INITRD
767 static void __init early_init_dt_check_for_initrd(unsigned long node)
768 {
769 	unsigned long l;
770 	u32 *prop;
771 
772 	DBG("Looking for initrd properties... ");
773 
774 	prop = of_get_flat_dt_prop(node, "linux,initrd-start", &l);
775 	if (prop) {
776 		initrd_start = (unsigned long)__va(of_read_ulong(prop, l/4));
777 
778 		prop = of_get_flat_dt_prop(node, "linux,initrd-end", &l);
779 		if (prop) {
780 			initrd_end = (unsigned long)
781 					__va(of_read_ulong(prop, l/4));
782 			initrd_below_start_ok = 1;
783 		} else {
784 			initrd_start = 0;
785 		}
786 	}
787 
788 	DBG("initrd_start=0x%lx  initrd_end=0x%lx\n", initrd_start, initrd_end);
789 }
790 #else
791 static inline void early_init_dt_check_for_initrd(unsigned long node)
792 {
793 }
794 #endif /* CONFIG_BLK_DEV_INITRD */
795 
796 static int __init early_init_dt_scan_chosen(unsigned long node,
797 					    const char *uname, int depth, void *data)
798 {
799 	unsigned long *lprop;
800 	unsigned long l;
801 	char *p;
802 
803 	DBG("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
804 
805 	if (depth != 1 ||
806 	    (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
807 		return 0;
808 
809 #ifdef CONFIG_PPC64
810 	/* check if iommu is forced on or off */
811 	if (of_get_flat_dt_prop(node, "linux,iommu-off", NULL) != NULL)
812 		iommu_is_off = 1;
813 	if (of_get_flat_dt_prop(node, "linux,iommu-force-on", NULL) != NULL)
814 		iommu_force_on = 1;
815 #endif
816 
817 	/* mem=x on the command line is the preferred mechanism */
818  	lprop = of_get_flat_dt_prop(node, "linux,memory-limit", NULL);
819  	if (lprop)
820  		memory_limit = *lprop;
821 
822 #ifdef CONFIG_PPC64
823  	lprop = of_get_flat_dt_prop(node, "linux,tce-alloc-start", NULL);
824  	if (lprop)
825  		tce_alloc_start = *lprop;
826  	lprop = of_get_flat_dt_prop(node, "linux,tce-alloc-end", NULL);
827  	if (lprop)
828  		tce_alloc_end = *lprop;
829 #endif
830 
831 #ifdef CONFIG_KEXEC
832 	lprop = of_get_flat_dt_prop(node, "linux,crashkernel-base", NULL);
833 	if (lprop)
834 		crashk_res.start = *lprop;
835 
836 	lprop = of_get_flat_dt_prop(node, "linux,crashkernel-size", NULL);
837 	if (lprop)
838 		crashk_res.end = crashk_res.start + *lprop - 1;
839 #endif
840 
841 	early_init_dt_check_for_initrd(node);
842 
843 	/* Retreive command line */
844  	p = of_get_flat_dt_prop(node, "bootargs", &l);
845 	if (p != NULL && l > 0)
846 		strlcpy(cmd_line, p, min((int)l, COMMAND_LINE_SIZE));
847 
848 #ifdef CONFIG_CMDLINE
849 	if (p == NULL || l == 0 || (l == 1 && (*p) == 0))
850 		strlcpy(cmd_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
851 #endif /* CONFIG_CMDLINE */
852 
853 	DBG("Command line is: %s\n", cmd_line);
854 
855 	/* break now */
856 	return 1;
857 }
858 
859 static int __init early_init_dt_scan_root(unsigned long node,
860 					  const char *uname, int depth, void *data)
861 {
862 	u32 *prop;
863 
864 	if (depth != 0)
865 		return 0;
866 
867 	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
868 	dt_root_size_cells = (prop == NULL) ? 1 : *prop;
869 	DBG("dt_root_size_cells = %x\n", dt_root_size_cells);
870 
871 	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
872 	dt_root_addr_cells = (prop == NULL) ? 2 : *prop;
873 	DBG("dt_root_addr_cells = %x\n", dt_root_addr_cells);
874 
875 	/* break now */
876 	return 1;
877 }
878 
879 static u64 __init dt_mem_next_cell(int s, cell_t **cellp)
880 {
881 	cell_t *p = *cellp;
882 
883 	*cellp = p + s;
884 	return of_read_number(p, s);
885 }
886 
887 #ifdef CONFIG_PPC_PSERIES
888 /*
889  * Interpret the ibm,dynamic-memory property in the
890  * /ibm,dynamic-reconfiguration-memory node.
891  * This contains a list of memory blocks along with NUMA affinity
892  * information.
893  */
894 static int __init early_init_dt_scan_drconf_memory(unsigned long node)
895 {
896 	cell_t *dm, *ls, *usm;
897 	unsigned long l, n, flags;
898 	u64 base, size, lmb_size;
899 	unsigned int is_kexec_kdump = 0, rngs;
900 
901 	ls = of_get_flat_dt_prop(node, "ibm,lmb-size", &l);
902 	if (ls == NULL || l < dt_root_size_cells * sizeof(cell_t))
903 		return 0;
904 	lmb_size = dt_mem_next_cell(dt_root_size_cells, &ls);
905 
906 	dm = of_get_flat_dt_prop(node, "ibm,dynamic-memory", &l);
907 	if (dm == NULL || l < sizeof(cell_t))
908 		return 0;
909 
910 	n = *dm++;	/* number of entries */
911 	if (l < (n * (dt_root_addr_cells + 4) + 1) * sizeof(cell_t))
912 		return 0;
913 
914 	/* check if this is a kexec/kdump kernel. */
915 	usm = of_get_flat_dt_prop(node, "linux,drconf-usable-memory",
916 						 &l);
917 	if (usm != NULL)
918 		is_kexec_kdump = 1;
919 
920 	for (; n != 0; --n) {
921 		base = dt_mem_next_cell(dt_root_addr_cells, &dm);
922 		flags = dm[3];
923 		/* skip DRC index, pad, assoc. list index, flags */
924 		dm += 4;
925 		/* skip this block if the reserved bit is set in flags (0x80)
926 		   or if the block is not assigned to this partition (0x8) */
927 		if ((flags & 0x80) || !(flags & 0x8))
928 			continue;
929 		size = lmb_size;
930 		rngs = 1;
931 		if (is_kexec_kdump) {
932 			/*
933 			 * For each lmb in ibm,dynamic-memory, a corresponding
934 			 * entry in linux,drconf-usable-memory property contains
935 			 * a counter 'p' followed by 'p' (base, size) duple.
936 			 * Now read the counter from
937 			 * linux,drconf-usable-memory property
938 			 */
939 			rngs = dt_mem_next_cell(dt_root_size_cells, &usm);
940 			if (!rngs) /* there are no (base, size) duple */
941 				continue;
942 		}
943 		do {
944 			if (is_kexec_kdump) {
945 				base = dt_mem_next_cell(dt_root_addr_cells,
946 							 &usm);
947 				size = dt_mem_next_cell(dt_root_size_cells,
948 							 &usm);
949 			}
950 			if (iommu_is_off) {
951 				if (base >= 0x80000000ul)
952 					continue;
953 				if ((base + size) > 0x80000000ul)
954 					size = 0x80000000ul - base;
955 			}
956 			lmb_add(base, size);
957 		} while (--rngs);
958 	}
959 	lmb_dump_all();
960 	return 0;
961 }
962 #else
963 #define early_init_dt_scan_drconf_memory(node)	0
964 #endif /* CONFIG_PPC_PSERIES */
965 
966 static int __init early_init_dt_scan_memory(unsigned long node,
967 					    const char *uname, int depth, void *data)
968 {
969 	char *type = of_get_flat_dt_prop(node, "device_type", NULL);
970 	cell_t *reg, *endp;
971 	unsigned long l;
972 
973 	/* Look for the ibm,dynamic-reconfiguration-memory node */
974 	if (depth == 1 &&
975 	    strcmp(uname, "ibm,dynamic-reconfiguration-memory") == 0)
976 		return early_init_dt_scan_drconf_memory(node);
977 
978 	/* We are scanning "memory" nodes only */
979 	if (type == NULL) {
980 		/*
981 		 * The longtrail doesn't have a device_type on the
982 		 * /memory node, so look for the node called /memory@0.
983 		 */
984 		if (depth != 1 || strcmp(uname, "memory@0") != 0)
985 			return 0;
986 	} else if (strcmp(type, "memory") != 0)
987 		return 0;
988 
989 	reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
990 	if (reg == NULL)
991 		reg = of_get_flat_dt_prop(node, "reg", &l);
992 	if (reg == NULL)
993 		return 0;
994 
995 	endp = reg + (l / sizeof(cell_t));
996 
997 	DBG("memory scan node %s, reg size %ld, data: %x %x %x %x,\n",
998 	    uname, l, reg[0], reg[1], reg[2], reg[3]);
999 
1000 	while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
1001 		u64 base, size;
1002 
1003 		base = dt_mem_next_cell(dt_root_addr_cells, &reg);
1004 		size = dt_mem_next_cell(dt_root_size_cells, &reg);
1005 
1006 		if (size == 0)
1007 			continue;
1008 		DBG(" - %llx ,  %llx\n", (unsigned long long)base,
1009 		    (unsigned long long)size);
1010 #ifdef CONFIG_PPC64
1011 		if (iommu_is_off) {
1012 			if (base >= 0x80000000ul)
1013 				continue;
1014 			if ((base + size) > 0x80000000ul)
1015 				size = 0x80000000ul - base;
1016 		}
1017 #endif
1018 		lmb_add(base, size);
1019 
1020 		memstart_addr = min((u64)memstart_addr, base);
1021 	}
1022 
1023 	return 0;
1024 }
1025 
1026 static void __init early_reserve_mem(void)
1027 {
1028 	u64 base, size;
1029 	u64 *reserve_map;
1030 	unsigned long self_base;
1031 	unsigned long self_size;
1032 
1033 	reserve_map = (u64 *)(((unsigned long)initial_boot_params) +
1034 					initial_boot_params->off_mem_rsvmap);
1035 
1036 	/* before we do anything, lets reserve the dt blob */
1037 	self_base = __pa((unsigned long)initial_boot_params);
1038 	self_size = initial_boot_params->totalsize;
1039 	lmb_reserve(self_base, self_size);
1040 
1041 #ifdef CONFIG_BLK_DEV_INITRD
1042 	/* then reserve the initrd, if any */
1043 	if (initrd_start && (initrd_end > initrd_start))
1044 		lmb_reserve(__pa(initrd_start), initrd_end - initrd_start);
1045 #endif /* CONFIG_BLK_DEV_INITRD */
1046 
1047 #ifdef CONFIG_PPC32
1048 	/*
1049 	 * Handle the case where we might be booting from an old kexec
1050 	 * image that setup the mem_rsvmap as pairs of 32-bit values
1051 	 */
1052 	if (*reserve_map > 0xffffffffull) {
1053 		u32 base_32, size_32;
1054 		u32 *reserve_map_32 = (u32 *)reserve_map;
1055 
1056 		while (1) {
1057 			base_32 = *(reserve_map_32++);
1058 			size_32 = *(reserve_map_32++);
1059 			if (size_32 == 0)
1060 				break;
1061 			/* skip if the reservation is for the blob */
1062 			if (base_32 == self_base && size_32 == self_size)
1063 				continue;
1064 			DBG("reserving: %x -> %x\n", base_32, size_32);
1065 			lmb_reserve(base_32, size_32);
1066 		}
1067 		return;
1068 	}
1069 #endif
1070 	while (1) {
1071 		base = *(reserve_map++);
1072 		size = *(reserve_map++);
1073 		if (size == 0)
1074 			break;
1075 		DBG("reserving: %llx -> %llx\n", base, size);
1076 		lmb_reserve(base, size);
1077 	}
1078 }
1079 
1080 #ifdef CONFIG_PHYP_DUMP
1081 /**
1082  * phyp_dump_calculate_reserve_size() - reserve variable boot area 5% or arg
1083  *
1084  * Function to find the largest size we need to reserve
1085  * during early boot process.
1086  *
1087  * It either looks for boot param and returns that OR
1088  * returns larger of 256 or 5% rounded down to multiples of 256MB.
1089  *
1090  */
1091 static inline unsigned long phyp_dump_calculate_reserve_size(void)
1092 {
1093 	unsigned long tmp;
1094 
1095 	if (phyp_dump_info->reserve_bootvar)
1096 		return phyp_dump_info->reserve_bootvar;
1097 
1098 	/* divide by 20 to get 5% of value */
1099 	tmp = lmb_end_of_DRAM();
1100 	do_div(tmp, 20);
1101 
1102 	/* round it down in multiples of 256 */
1103 	tmp = tmp & ~0x0FFFFFFFUL;
1104 
1105 	return (tmp > PHYP_DUMP_RMR_END ? tmp : PHYP_DUMP_RMR_END);
1106 }
1107 
1108 /**
1109  * phyp_dump_reserve_mem() - reserve all not-yet-dumped mmemory
1110  *
1111  * This routine may reserve memory regions in the kernel only
1112  * if the system is supported and a dump was taken in last
1113  * boot instance or if the hardware is supported and the
1114  * scratch area needs to be setup. In other instances it returns
1115  * without reserving anything. The memory in case of dump being
1116  * active is freed when the dump is collected (by userland tools).
1117  */
1118 static void __init phyp_dump_reserve_mem(void)
1119 {
1120 	unsigned long base, size;
1121 	unsigned long variable_reserve_size;
1122 
1123 	if (!phyp_dump_info->phyp_dump_configured) {
1124 		printk(KERN_ERR "Phyp-dump not supported on this hardware\n");
1125 		return;
1126 	}
1127 
1128 	if (!phyp_dump_info->phyp_dump_at_boot) {
1129 		printk(KERN_INFO "Phyp-dump disabled at boot time\n");
1130 		return;
1131 	}
1132 
1133 	variable_reserve_size = phyp_dump_calculate_reserve_size();
1134 
1135 	if (phyp_dump_info->phyp_dump_is_active) {
1136 		/* Reserve *everything* above RMR.Area freed by userland tools*/
1137 		base = variable_reserve_size;
1138 		size = lmb_end_of_DRAM() - base;
1139 
1140 		/* XXX crashed_ram_end is wrong, since it may be beyond
1141 		 * the memory_limit, it will need to be adjusted. */
1142 		lmb_reserve(base, size);
1143 
1144 		phyp_dump_info->init_reserve_start = base;
1145 		phyp_dump_info->init_reserve_size = size;
1146 	} else {
1147 		size = phyp_dump_info->cpu_state_size +
1148 			phyp_dump_info->hpte_region_size +
1149 			variable_reserve_size;
1150 		base = lmb_end_of_DRAM() - size;
1151 		lmb_reserve(base, size);
1152 		phyp_dump_info->init_reserve_start = base;
1153 		phyp_dump_info->init_reserve_size = size;
1154 	}
1155 }
1156 #else
1157 static inline void __init phyp_dump_reserve_mem(void) {}
1158 #endif /* CONFIG_PHYP_DUMP  && CONFIG_PPC_RTAS */
1159 
1160 
1161 void __init early_init_devtree(void *params)
1162 {
1163 	unsigned long limit;
1164 
1165 	DBG(" -> early_init_devtree(%p)\n", params);
1166 
1167 	/* Setup flat device-tree pointer */
1168 	initial_boot_params = params;
1169 
1170 #ifdef CONFIG_PPC_RTAS
1171 	/* Some machines might need RTAS info for debugging, grab it now. */
1172 	of_scan_flat_dt(early_init_dt_scan_rtas, NULL);
1173 #endif
1174 
1175 #ifdef CONFIG_PHYP_DUMP
1176 	/* scan tree to see if dump occured during last boot */
1177 	of_scan_flat_dt(early_init_dt_scan_phyp_dump, NULL);
1178 #endif
1179 
1180 	/* Retrieve various informations from the /chosen node of the
1181 	 * device-tree, including the platform type, initrd location and
1182 	 * size, TCE reserve, and more ...
1183 	 */
1184 	of_scan_flat_dt(early_init_dt_scan_chosen, NULL);
1185 
1186 	/* Scan memory nodes and rebuild LMBs */
1187 	lmb_init();
1188 	of_scan_flat_dt(early_init_dt_scan_root, NULL);
1189 	of_scan_flat_dt(early_init_dt_scan_memory, NULL);
1190 
1191 	/* Save command line for /proc/cmdline and then parse parameters */
1192 	strlcpy(boot_command_line, cmd_line, COMMAND_LINE_SIZE);
1193 	parse_early_param();
1194 
1195 	/* Reserve LMB regions used by kernel, initrd, dt, etc... */
1196 	lmb_reserve(PHYSICAL_START, __pa(klimit) - PHYSICAL_START);
1197 	/* If relocatable, reserve first 32k for interrupt vectors etc. */
1198 	if (PHYSICAL_START > MEMORY_START)
1199 		lmb_reserve(MEMORY_START, 0x8000);
1200 	reserve_kdump_trampoline();
1201 	reserve_crashkernel();
1202 	early_reserve_mem();
1203 	phyp_dump_reserve_mem();
1204 
1205 	limit = memory_limit;
1206 	if (! limit) {
1207 		unsigned long memsize;
1208 
1209 		/* Ensure that total memory size is page-aligned, because
1210 		 * otherwise mark_bootmem() gets upset. */
1211 		lmb_analyze();
1212 		memsize = lmb_phys_mem_size();
1213 		if ((memsize & PAGE_MASK) != memsize)
1214 			limit = memsize & PAGE_MASK;
1215 	}
1216 	lmb_enforce_memory_limit(limit);
1217 
1218 	lmb_analyze();
1219 	lmb_dump_all();
1220 
1221 	DBG("Phys. mem: %lx\n", lmb_phys_mem_size());
1222 
1223 	/* We may need to relocate the flat tree, do it now.
1224 	 * FIXME .. and the initrd too? */
1225 	move_device_tree();
1226 
1227 	DBG("Scanning CPUs ...\n");
1228 
1229 	/* Retreive CPU related informations from the flat tree
1230 	 * (altivec support, boot CPU ID, ...)
1231 	 */
1232 	of_scan_flat_dt(early_init_dt_scan_cpus, NULL);
1233 
1234 	DBG(" <- early_init_devtree()\n");
1235 }
1236 
1237 
1238 /**
1239  * Indicates whether the root node has a given value in its
1240  * compatible property.
1241  */
1242 int machine_is_compatible(const char *compat)
1243 {
1244 	struct device_node *root;
1245 	int rc = 0;
1246 
1247 	root = of_find_node_by_path("/");
1248 	if (root) {
1249 		rc = of_device_is_compatible(root, compat);
1250 		of_node_put(root);
1251 	}
1252 	return rc;
1253 }
1254 EXPORT_SYMBOL(machine_is_compatible);
1255 
1256 /*******
1257  *
1258  * New implementation of the OF "find" APIs, return a refcounted
1259  * object, call of_node_put() when done.  The device tree and list
1260  * are protected by a rw_lock.
1261  *
1262  * Note that property management will need some locking as well,
1263  * this isn't dealt with yet.
1264  *
1265  *******/
1266 
1267 /**
1268  *	of_find_node_by_phandle - Find a node given a phandle
1269  *	@handle:	phandle of the node to find
1270  *
1271  *	Returns a node pointer with refcount incremented, use
1272  *	of_node_put() on it when done.
1273  */
1274 struct device_node *of_find_node_by_phandle(phandle handle)
1275 {
1276 	struct device_node *np;
1277 
1278 	read_lock(&devtree_lock);
1279 	for (np = allnodes; np != 0; np = np->allnext)
1280 		if (np->linux_phandle == handle)
1281 			break;
1282 	of_node_get(np);
1283 	read_unlock(&devtree_lock);
1284 	return np;
1285 }
1286 EXPORT_SYMBOL(of_find_node_by_phandle);
1287 
1288 /**
1289  *	of_find_next_cache_node - Find a node's subsidiary cache
1290  *	@np:	node of type "cpu" or "cache"
1291  *
1292  *	Returns a node pointer with refcount incremented, use
1293  *	of_node_put() on it when done.  Caller should hold a reference
1294  *	to np.
1295  */
1296 struct device_node *of_find_next_cache_node(struct device_node *np)
1297 {
1298 	struct device_node *child;
1299 	const phandle *handle;
1300 
1301 	handle = of_get_property(np, "l2-cache", NULL);
1302 	if (!handle)
1303 		handle = of_get_property(np, "next-level-cache", NULL);
1304 
1305 	if (handle)
1306 		return of_find_node_by_phandle(*handle);
1307 
1308 	/* OF on pmac has nodes instead of properties named "l2-cache"
1309 	 * beneath CPU nodes.
1310 	 */
1311 	if (!strcmp(np->type, "cpu"))
1312 		for_each_child_of_node(np, child)
1313 			if (!strcmp(child->type, "cache"))
1314 				return child;
1315 
1316 	return NULL;
1317 }
1318 
1319 /**
1320  *	of_find_all_nodes - Get next node in global list
1321  *	@prev:	Previous node or NULL to start iteration
1322  *		of_node_put() will be called on it
1323  *
1324  *	Returns a node pointer with refcount incremented, use
1325  *	of_node_put() on it when done.
1326  */
1327 struct device_node *of_find_all_nodes(struct device_node *prev)
1328 {
1329 	struct device_node *np;
1330 
1331 	read_lock(&devtree_lock);
1332 	np = prev ? prev->allnext : allnodes;
1333 	for (; np != 0; np = np->allnext)
1334 		if (of_node_get(np))
1335 			break;
1336 	of_node_put(prev);
1337 	read_unlock(&devtree_lock);
1338 	return np;
1339 }
1340 EXPORT_SYMBOL(of_find_all_nodes);
1341 
1342 /**
1343  *	of_node_get - Increment refcount of a node
1344  *	@node:	Node to inc refcount, NULL is supported to
1345  *		simplify writing of callers
1346  *
1347  *	Returns node.
1348  */
1349 struct device_node *of_node_get(struct device_node *node)
1350 {
1351 	if (node)
1352 		kref_get(&node->kref);
1353 	return node;
1354 }
1355 EXPORT_SYMBOL(of_node_get);
1356 
1357 static inline struct device_node * kref_to_device_node(struct kref *kref)
1358 {
1359 	return container_of(kref, struct device_node, kref);
1360 }
1361 
1362 /**
1363  *	of_node_release - release a dynamically allocated node
1364  *	@kref:  kref element of the node to be released
1365  *
1366  *	In of_node_put() this function is passed to kref_put()
1367  *	as the destructor.
1368  */
1369 static void of_node_release(struct kref *kref)
1370 {
1371 	struct device_node *node = kref_to_device_node(kref);
1372 	struct property *prop = node->properties;
1373 
1374 	/* We should never be releasing nodes that haven't been detached. */
1375 	if (!of_node_check_flag(node, OF_DETACHED)) {
1376 		printk("WARNING: Bad of_node_put() on %s\n", node->full_name);
1377 		dump_stack();
1378 		kref_init(&node->kref);
1379 		return;
1380 	}
1381 
1382 	if (!of_node_check_flag(node, OF_DYNAMIC))
1383 		return;
1384 
1385 	while (prop) {
1386 		struct property *next = prop->next;
1387 		kfree(prop->name);
1388 		kfree(prop->value);
1389 		kfree(prop);
1390 		prop = next;
1391 
1392 		if (!prop) {
1393 			prop = node->deadprops;
1394 			node->deadprops = NULL;
1395 		}
1396 	}
1397 	kfree(node->full_name);
1398 	kfree(node->data);
1399 	kfree(node);
1400 }
1401 
1402 /**
1403  *	of_node_put - Decrement refcount of a node
1404  *	@node:	Node to dec refcount, NULL is supported to
1405  *		simplify writing of callers
1406  *
1407  */
1408 void of_node_put(struct device_node *node)
1409 {
1410 	if (node)
1411 		kref_put(&node->kref, of_node_release);
1412 }
1413 EXPORT_SYMBOL(of_node_put);
1414 
1415 /*
1416  * Plug a device node into the tree and global list.
1417  */
1418 void of_attach_node(struct device_node *np)
1419 {
1420 	unsigned long flags;
1421 
1422 	write_lock_irqsave(&devtree_lock, flags);
1423 	np->sibling = np->parent->child;
1424 	np->allnext = allnodes;
1425 	np->parent->child = np;
1426 	allnodes = np;
1427 	write_unlock_irqrestore(&devtree_lock, flags);
1428 }
1429 
1430 /*
1431  * "Unplug" a node from the device tree.  The caller must hold
1432  * a reference to the node.  The memory associated with the node
1433  * is not freed until its refcount goes to zero.
1434  */
1435 void of_detach_node(struct device_node *np)
1436 {
1437 	struct device_node *parent;
1438 	unsigned long flags;
1439 
1440 	write_lock_irqsave(&devtree_lock, flags);
1441 
1442 	parent = np->parent;
1443 	if (!parent)
1444 		goto out_unlock;
1445 
1446 	if (allnodes == np)
1447 		allnodes = np->allnext;
1448 	else {
1449 		struct device_node *prev;
1450 		for (prev = allnodes;
1451 		     prev->allnext != np;
1452 		     prev = prev->allnext)
1453 			;
1454 		prev->allnext = np->allnext;
1455 	}
1456 
1457 	if (parent->child == np)
1458 		parent->child = np->sibling;
1459 	else {
1460 		struct device_node *prevsib;
1461 		for (prevsib = np->parent->child;
1462 		     prevsib->sibling != np;
1463 		     prevsib = prevsib->sibling)
1464 			;
1465 		prevsib->sibling = np->sibling;
1466 	}
1467 
1468 	of_node_set_flag(np, OF_DETACHED);
1469 
1470 out_unlock:
1471 	write_unlock_irqrestore(&devtree_lock, flags);
1472 }
1473 
1474 #ifdef CONFIG_PPC_PSERIES
1475 /*
1476  * Fix up the uninitialized fields in a new device node:
1477  * name, type and pci-specific fields
1478  */
1479 
1480 static int of_finish_dynamic_node(struct device_node *node)
1481 {
1482 	struct device_node *parent = of_get_parent(node);
1483 	int err = 0;
1484 	const phandle *ibm_phandle;
1485 
1486 	node->name = of_get_property(node, "name", NULL);
1487 	node->type = of_get_property(node, "device_type", NULL);
1488 
1489 	if (!node->name)
1490 		node->name = "<NULL>";
1491 	if (!node->type)
1492 		node->type = "<NULL>";
1493 
1494 	if (!parent) {
1495 		err = -ENODEV;
1496 		goto out;
1497 	}
1498 
1499 	/* We don't support that function on PowerMac, at least
1500 	 * not yet
1501 	 */
1502 	if (machine_is(powermac))
1503 		return -ENODEV;
1504 
1505 	/* fix up new node's linux_phandle field */
1506 	if ((ibm_phandle = of_get_property(node, "ibm,phandle", NULL)))
1507 		node->linux_phandle = *ibm_phandle;
1508 
1509 out:
1510 	of_node_put(parent);
1511 	return err;
1512 }
1513 
1514 static int prom_reconfig_notifier(struct notifier_block *nb,
1515 				  unsigned long action, void *node)
1516 {
1517 	int err;
1518 
1519 	switch (action) {
1520 	case PSERIES_RECONFIG_ADD:
1521 		err = of_finish_dynamic_node(node);
1522 		if (err < 0) {
1523 			printk(KERN_ERR "finish_node returned %d\n", err);
1524 			err = NOTIFY_BAD;
1525 		}
1526 		break;
1527 	default:
1528 		err = NOTIFY_DONE;
1529 		break;
1530 	}
1531 	return err;
1532 }
1533 
1534 static struct notifier_block prom_reconfig_nb = {
1535 	.notifier_call = prom_reconfig_notifier,
1536 	.priority = 10, /* This one needs to run first */
1537 };
1538 
1539 static int __init prom_reconfig_setup(void)
1540 {
1541 	return pSeries_reconfig_notifier_register(&prom_reconfig_nb);
1542 }
1543 __initcall(prom_reconfig_setup);
1544 #endif
1545 
1546 /*
1547  * Add a property to a node
1548  */
1549 int prom_add_property(struct device_node* np, struct property* prop)
1550 {
1551 	struct property **next;
1552 	unsigned long flags;
1553 
1554 	prop->next = NULL;
1555 	write_lock_irqsave(&devtree_lock, flags);
1556 	next = &np->properties;
1557 	while (*next) {
1558 		if (strcmp(prop->name, (*next)->name) == 0) {
1559 			/* duplicate ! don't insert it */
1560 			write_unlock_irqrestore(&devtree_lock, flags);
1561 			return -1;
1562 		}
1563 		next = &(*next)->next;
1564 	}
1565 	*next = prop;
1566 	write_unlock_irqrestore(&devtree_lock, flags);
1567 
1568 #ifdef CONFIG_PROC_DEVICETREE
1569 	/* try to add to proc as well if it was initialized */
1570 	if (np->pde)
1571 		proc_device_tree_add_prop(np->pde, prop);
1572 #endif /* CONFIG_PROC_DEVICETREE */
1573 
1574 	return 0;
1575 }
1576 
1577 /*
1578  * Remove a property from a node.  Note that we don't actually
1579  * remove it, since we have given out who-knows-how-many pointers
1580  * to the data using get-property.  Instead we just move the property
1581  * to the "dead properties" list, so it won't be found any more.
1582  */
1583 int prom_remove_property(struct device_node *np, struct property *prop)
1584 {
1585 	struct property **next;
1586 	unsigned long flags;
1587 	int found = 0;
1588 
1589 	write_lock_irqsave(&devtree_lock, flags);
1590 	next = &np->properties;
1591 	while (*next) {
1592 		if (*next == prop) {
1593 			/* found the node */
1594 			*next = prop->next;
1595 			prop->next = np->deadprops;
1596 			np->deadprops = prop;
1597 			found = 1;
1598 			break;
1599 		}
1600 		next = &(*next)->next;
1601 	}
1602 	write_unlock_irqrestore(&devtree_lock, flags);
1603 
1604 	if (!found)
1605 		return -ENODEV;
1606 
1607 #ifdef CONFIG_PROC_DEVICETREE
1608 	/* try to remove the proc node as well */
1609 	if (np->pde)
1610 		proc_device_tree_remove_prop(np->pde, prop);
1611 #endif /* CONFIG_PROC_DEVICETREE */
1612 
1613 	return 0;
1614 }
1615 
1616 /*
1617  * Update a property in a node.  Note that we don't actually
1618  * remove it, since we have given out who-knows-how-many pointers
1619  * to the data using get-property.  Instead we just move the property
1620  * to the "dead properties" list, and add the new property to the
1621  * property list
1622  */
1623 int prom_update_property(struct device_node *np,
1624 			 struct property *newprop,
1625 			 struct property *oldprop)
1626 {
1627 	struct property **next;
1628 	unsigned long flags;
1629 	int found = 0;
1630 
1631 	write_lock_irqsave(&devtree_lock, flags);
1632 	next = &np->properties;
1633 	while (*next) {
1634 		if (*next == oldprop) {
1635 			/* found the node */
1636 			newprop->next = oldprop->next;
1637 			*next = newprop;
1638 			oldprop->next = np->deadprops;
1639 			np->deadprops = oldprop;
1640 			found = 1;
1641 			break;
1642 		}
1643 		next = &(*next)->next;
1644 	}
1645 	write_unlock_irqrestore(&devtree_lock, flags);
1646 
1647 	if (!found)
1648 		return -ENODEV;
1649 
1650 #ifdef CONFIG_PROC_DEVICETREE
1651 	/* try to add to proc as well if it was initialized */
1652 	if (np->pde)
1653 		proc_device_tree_update_prop(np->pde, newprop, oldprop);
1654 #endif /* CONFIG_PROC_DEVICETREE */
1655 
1656 	return 0;
1657 }
1658 
1659 
1660 /* Find the device node for a given logical cpu number, also returns the cpu
1661  * local thread number (index in ibm,interrupt-server#s) if relevant and
1662  * asked for (non NULL)
1663  */
1664 struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
1665 {
1666 	int hardid;
1667 	struct device_node *np;
1668 
1669 	hardid = get_hard_smp_processor_id(cpu);
1670 
1671 	for_each_node_by_type(np, "cpu") {
1672 		const u32 *intserv;
1673 		unsigned int plen, t;
1674 
1675 		/* Check for ibm,ppc-interrupt-server#s. If it doesn't exist
1676 		 * fallback to "reg" property and assume no threads
1677 		 */
1678 		intserv = of_get_property(np, "ibm,ppc-interrupt-server#s",
1679 				&plen);
1680 		if (intserv == NULL) {
1681 			const u32 *reg = of_get_property(np, "reg", NULL);
1682 			if (reg == NULL)
1683 				continue;
1684 			if (*reg == hardid) {
1685 				if (thread)
1686 					*thread = 0;
1687 				return np;
1688 			}
1689 		} else {
1690 			plen /= sizeof(u32);
1691 			for (t = 0; t < plen; t++) {
1692 				if (hardid == intserv[t]) {
1693 					if (thread)
1694 						*thread = t;
1695 					return np;
1696 				}
1697 			}
1698 		}
1699 	}
1700 	return NULL;
1701 }
1702 EXPORT_SYMBOL(of_get_cpu_node);
1703 
1704 #if defined(CONFIG_DEBUG_FS) && defined(DEBUG)
1705 static struct debugfs_blob_wrapper flat_dt_blob;
1706 
1707 static int __init export_flat_device_tree(void)
1708 {
1709 	struct dentry *d;
1710 
1711 	flat_dt_blob.data = initial_boot_params;
1712 	flat_dt_blob.size = initial_boot_params->totalsize;
1713 
1714 	d = debugfs_create_blob("flat-device-tree", S_IFREG | S_IRUSR,
1715 				powerpc_debugfs_root, &flat_dt_blob);
1716 	if (!d)
1717 		return 1;
1718 
1719 	return 0;
1720 }
1721 __initcall(export_flat_device_tree);
1722 #endif
1723