xref: /openbmc/linux/arch/powerpc/kernel/prom.c (revision 30686ba6)
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 
35 #include <asm/prom.h>
36 #include <asm/rtas.h>
37 #include <asm/lmb.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/kexec.h>
55 
56 #ifdef DEBUG
57 #define DBG(fmt...) printk(KERN_ERR fmt)
58 #else
59 #define DBG(fmt...)
60 #endif
61 
62 
63 static int __initdata dt_root_addr_cells;
64 static int __initdata dt_root_size_cells;
65 
66 #ifdef CONFIG_PPC64
67 int __initdata iommu_is_off;
68 int __initdata iommu_force_on;
69 unsigned long tce_alloc_start, tce_alloc_end;
70 #endif
71 
72 typedef u32 cell_t;
73 
74 #if 0
75 static struct boot_param_header *initial_boot_params __initdata;
76 #else
77 struct boot_param_header *initial_boot_params;
78 #endif
79 
80 static struct device_node *allnodes = NULL;
81 
82 /* use when traversing tree through the allnext, child, sibling,
83  * or parent members of struct device_node.
84  */
85 static DEFINE_RWLOCK(devtree_lock);
86 
87 /* export that to outside world */
88 struct device_node *of_chosen;
89 
90 static inline char *find_flat_dt_string(u32 offset)
91 {
92 	return ((char *)initial_boot_params) +
93 		initial_boot_params->off_dt_strings + offset;
94 }
95 
96 /**
97  * This function is used to scan the flattened device-tree, it is
98  * used to extract the memory informations at boot before we can
99  * unflatten the tree
100  */
101 int __init of_scan_flat_dt(int (*it)(unsigned long node,
102 				     const char *uname, int depth,
103 				     void *data),
104 			   void *data)
105 {
106 	unsigned long p = ((unsigned long)initial_boot_params) +
107 		initial_boot_params->off_dt_struct;
108 	int rc = 0;
109 	int depth = -1;
110 
111 	do {
112 		u32 tag = *((u32 *)p);
113 		char *pathp;
114 
115 		p += 4;
116 		if (tag == OF_DT_END_NODE) {
117 			depth --;
118 			continue;
119 		}
120 		if (tag == OF_DT_NOP)
121 			continue;
122 		if (tag == OF_DT_END)
123 			break;
124 		if (tag == OF_DT_PROP) {
125 			u32 sz = *((u32 *)p);
126 			p += 8;
127 			if (initial_boot_params->version < 0x10)
128 				p = _ALIGN(p, sz >= 8 ? 8 : 4);
129 			p += sz;
130 			p = _ALIGN(p, 4);
131 			continue;
132 		}
133 		if (tag != OF_DT_BEGIN_NODE) {
134 			printk(KERN_WARNING "Invalid tag %x scanning flattened"
135 			       " device tree !\n", tag);
136 			return -EINVAL;
137 		}
138 		depth++;
139 		pathp = (char *)p;
140 		p = _ALIGN(p + strlen(pathp) + 1, 4);
141 		if ((*pathp) == '/') {
142 			char *lp, *np;
143 			for (lp = NULL, np = pathp; *np; np++)
144 				if ((*np) == '/')
145 					lp = np+1;
146 			if (lp != NULL)
147 				pathp = lp;
148 		}
149 		rc = it(p, pathp, depth, data);
150 		if (rc != 0)
151 			break;
152 	} while(1);
153 
154 	return rc;
155 }
156 
157 unsigned long __init of_get_flat_dt_root(void)
158 {
159 	unsigned long p = ((unsigned long)initial_boot_params) +
160 		initial_boot_params->off_dt_struct;
161 
162 	while(*((u32 *)p) == OF_DT_NOP)
163 		p += 4;
164 	BUG_ON (*((u32 *)p) != OF_DT_BEGIN_NODE);
165 	p += 4;
166 	return _ALIGN(p + strlen((char *)p) + 1, 4);
167 }
168 
169 /**
170  * This  function can be used within scan_flattened_dt callback to get
171  * access to properties
172  */
173 void* __init of_get_flat_dt_prop(unsigned long node, const char *name,
174 				 unsigned long *size)
175 {
176 	unsigned long p = node;
177 
178 	do {
179 		u32 tag = *((u32 *)p);
180 		u32 sz, noff;
181 		const char *nstr;
182 
183 		p += 4;
184 		if (tag == OF_DT_NOP)
185 			continue;
186 		if (tag != OF_DT_PROP)
187 			return NULL;
188 
189 		sz = *((u32 *)p);
190 		noff = *((u32 *)(p + 4));
191 		p += 8;
192 		if (initial_boot_params->version < 0x10)
193 			p = _ALIGN(p, sz >= 8 ? 8 : 4);
194 
195 		nstr = find_flat_dt_string(noff);
196 		if (nstr == NULL) {
197 			printk(KERN_WARNING "Can't find property index"
198 			       " name !\n");
199 			return NULL;
200 		}
201 		if (strcmp(name, nstr) == 0) {
202 			if (size)
203 				*size = sz;
204 			return (void *)p;
205 		}
206 		p += sz;
207 		p = _ALIGN(p, 4);
208 	} while(1);
209 }
210 
211 int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
212 {
213 	const char* cp;
214 	unsigned long cplen, l;
215 
216 	cp = of_get_flat_dt_prop(node, "compatible", &cplen);
217 	if (cp == NULL)
218 		return 0;
219 	while (cplen > 0) {
220 		if (strncasecmp(cp, compat, strlen(compat)) == 0)
221 			return 1;
222 		l = strlen(cp) + 1;
223 		cp += l;
224 		cplen -= l;
225 	}
226 
227 	return 0;
228 }
229 
230 static void *__init unflatten_dt_alloc(unsigned long *mem, unsigned long size,
231 				       unsigned long align)
232 {
233 	void *res;
234 
235 	*mem = _ALIGN(*mem, align);
236 	res = (void *)*mem;
237 	*mem += size;
238 
239 	return res;
240 }
241 
242 static unsigned long __init unflatten_dt_node(unsigned long mem,
243 					      unsigned long *p,
244 					      struct device_node *dad,
245 					      struct device_node ***allnextpp,
246 					      unsigned long fpsize)
247 {
248 	struct device_node *np;
249 	struct property *pp, **prev_pp = NULL;
250 	char *pathp;
251 	u32 tag;
252 	unsigned int l, allocl;
253 	int has_name = 0;
254 	int new_format = 0;
255 
256 	tag = *((u32 *)(*p));
257 	if (tag != OF_DT_BEGIN_NODE) {
258 		printk("Weird tag at start of node: %x\n", tag);
259 		return mem;
260 	}
261 	*p += 4;
262 	pathp = (char *)*p;
263 	l = allocl = strlen(pathp) + 1;
264 	*p = _ALIGN(*p + l, 4);
265 
266 	/* version 0x10 has a more compact unit name here instead of the full
267 	 * path. we accumulate the full path size using "fpsize", we'll rebuild
268 	 * it later. We detect this because the first character of the name is
269 	 * not '/'.
270 	 */
271 	if ((*pathp) != '/') {
272 		new_format = 1;
273 		if (fpsize == 0) {
274 			/* root node: special case. fpsize accounts for path
275 			 * plus terminating zero. root node only has '/', so
276 			 * fpsize should be 2, but we want to avoid the first
277 			 * level nodes to have two '/' so we use fpsize 1 here
278 			 */
279 			fpsize = 1;
280 			allocl = 2;
281 		} else {
282 			/* account for '/' and path size minus terminal 0
283 			 * already in 'l'
284 			 */
285 			fpsize += l;
286 			allocl = fpsize;
287 		}
288 	}
289 
290 
291 	np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
292 				__alignof__(struct device_node));
293 	if (allnextpp) {
294 		memset(np, 0, sizeof(*np));
295 		np->full_name = ((char*)np) + sizeof(struct device_node);
296 		if (new_format) {
297 			char *p = np->full_name;
298 			/* rebuild full path for new format */
299 			if (dad && dad->parent) {
300 				strcpy(p, dad->full_name);
301 #ifdef DEBUG
302 				if ((strlen(p) + l + 1) != allocl) {
303 					DBG("%s: p: %d, l: %d, a: %d\n",
304 					    pathp, (int)strlen(p), l, allocl);
305 				}
306 #endif
307 				p += strlen(p);
308 			}
309 			*(p++) = '/';
310 			memcpy(p, pathp, l);
311 		} else
312 			memcpy(np->full_name, pathp, l);
313 		prev_pp = &np->properties;
314 		**allnextpp = np;
315 		*allnextpp = &np->allnext;
316 		if (dad != NULL) {
317 			np->parent = dad;
318 			/* we temporarily use the next field as `last_child'*/
319 			if (dad->next == 0)
320 				dad->child = np;
321 			else
322 				dad->next->sibling = np;
323 			dad->next = np;
324 		}
325 		kref_init(&np->kref);
326 	}
327 	while(1) {
328 		u32 sz, noff;
329 		char *pname;
330 
331 		tag = *((u32 *)(*p));
332 		if (tag == OF_DT_NOP) {
333 			*p += 4;
334 			continue;
335 		}
336 		if (tag != OF_DT_PROP)
337 			break;
338 		*p += 4;
339 		sz = *((u32 *)(*p));
340 		noff = *((u32 *)((*p) + 4));
341 		*p += 8;
342 		if (initial_boot_params->version < 0x10)
343 			*p = _ALIGN(*p, sz >= 8 ? 8 : 4);
344 
345 		pname = find_flat_dt_string(noff);
346 		if (pname == NULL) {
347 			printk("Can't find property name in list !\n");
348 			break;
349 		}
350 		if (strcmp(pname, "name") == 0)
351 			has_name = 1;
352 		l = strlen(pname) + 1;
353 		pp = unflatten_dt_alloc(&mem, sizeof(struct property),
354 					__alignof__(struct property));
355 		if (allnextpp) {
356 			if (strcmp(pname, "linux,phandle") == 0) {
357 				np->node = *((u32 *)*p);
358 				if (np->linux_phandle == 0)
359 					np->linux_phandle = np->node;
360 			}
361 			if (strcmp(pname, "ibm,phandle") == 0)
362 				np->linux_phandle = *((u32 *)*p);
363 			pp->name = pname;
364 			pp->length = sz;
365 			pp->value = (void *)*p;
366 			*prev_pp = pp;
367 			prev_pp = &pp->next;
368 		}
369 		*p = _ALIGN((*p) + sz, 4);
370 	}
371 	/* with version 0x10 we may not have the name property, recreate
372 	 * it here from the unit name if absent
373 	 */
374 	if (!has_name) {
375 		char *p = pathp, *ps = pathp, *pa = NULL;
376 		int sz;
377 
378 		while (*p) {
379 			if ((*p) == '@')
380 				pa = p;
381 			if ((*p) == '/')
382 				ps = p + 1;
383 			p++;
384 		}
385 		if (pa < ps)
386 			pa = p;
387 		sz = (pa - ps) + 1;
388 		pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
389 					__alignof__(struct property));
390 		if (allnextpp) {
391 			pp->name = "name";
392 			pp->length = sz;
393 			pp->value = pp + 1;
394 			*prev_pp = pp;
395 			prev_pp = &pp->next;
396 			memcpy(pp->value, ps, sz - 1);
397 			((char *)pp->value)[sz - 1] = 0;
398 			DBG("fixed up name for %s -> %s\n", pathp,
399 				(char *)pp->value);
400 		}
401 	}
402 	if (allnextpp) {
403 		*prev_pp = NULL;
404 		np->name = of_get_property(np, "name", NULL);
405 		np->type = of_get_property(np, "device_type", NULL);
406 
407 		if (!np->name)
408 			np->name = "<NULL>";
409 		if (!np->type)
410 			np->type = "<NULL>";
411 	}
412 	while (tag == OF_DT_BEGIN_NODE) {
413 		mem = unflatten_dt_node(mem, p, np, allnextpp, fpsize);
414 		tag = *((u32 *)(*p));
415 	}
416 	if (tag != OF_DT_END_NODE) {
417 		printk("Weird tag at end of node: %x\n", tag);
418 		return mem;
419 	}
420 	*p += 4;
421 	return mem;
422 }
423 
424 static int __init early_parse_mem(char *p)
425 {
426 	if (!p)
427 		return 1;
428 
429 	memory_limit = PAGE_ALIGN(memparse(p, &p));
430 	DBG("memory limit = 0x%lx\n", memory_limit);
431 
432 	return 0;
433 }
434 early_param("mem", early_parse_mem);
435 
436 /*
437  * The device tree may be allocated below our memory limit, or inside the
438  * crash kernel region for kdump. If so, move it out now.
439  */
440 static void move_device_tree(void)
441 {
442 	unsigned long start, size;
443 	void *p;
444 
445 	DBG("-> move_device_tree\n");
446 
447 	start = __pa(initial_boot_params);
448 	size = initial_boot_params->totalsize;
449 
450 	if ((memory_limit && (start + size) > memory_limit) ||
451 			overlaps_crashkernel(start, size)) {
452 		p = __va(lmb_alloc_base(size, PAGE_SIZE, lmb.rmo_size));
453 		memcpy(p, initial_boot_params, size);
454 		initial_boot_params = (struct boot_param_header *)p;
455 		DBG("Moved device tree to 0x%p\n", p);
456 	}
457 
458 	DBG("<- move_device_tree\n");
459 }
460 
461 /**
462  * unflattens the device-tree passed by the firmware, creating the
463  * tree of struct device_node. It also fills the "name" and "type"
464  * pointers of the nodes so the normal device-tree walking functions
465  * can be used (this used to be done by finish_device_tree)
466  */
467 void __init unflatten_device_tree(void)
468 {
469 	unsigned long start, mem, size;
470 	struct device_node **allnextp = &allnodes;
471 
472 	DBG(" -> unflatten_device_tree()\n");
473 
474 	/* First pass, scan for size */
475 	start = ((unsigned long)initial_boot_params) +
476 		initial_boot_params->off_dt_struct;
477 	size = unflatten_dt_node(0, &start, NULL, NULL, 0);
478 	size = (size | 3) + 1;
479 
480 	DBG("  size is %lx, allocating...\n", size);
481 
482 	/* Allocate memory for the expanded device tree */
483 	mem = lmb_alloc(size + 4, __alignof__(struct device_node));
484 	mem = (unsigned long) __va(mem);
485 
486 	((u32 *)mem)[size / 4] = 0xdeadbeef;
487 
488 	DBG("  unflattening %lx...\n", mem);
489 
490 	/* Second pass, do actual unflattening */
491 	start = ((unsigned long)initial_boot_params) +
492 		initial_boot_params->off_dt_struct;
493 	unflatten_dt_node(mem, &start, NULL, &allnextp, 0);
494 	if (*((u32 *)start) != OF_DT_END)
495 		printk(KERN_WARNING "Weird tag at end of tree: %08x\n", *((u32 *)start));
496 	if (((u32 *)mem)[size / 4] != 0xdeadbeef)
497 		printk(KERN_WARNING "End of tree marker overwritten: %08x\n",
498 		       ((u32 *)mem)[size / 4] );
499 	*allnextp = NULL;
500 
501 	/* Get pointer to OF "/chosen" node for use everywhere */
502 	of_chosen = of_find_node_by_path("/chosen");
503 	if (of_chosen == NULL)
504 		of_chosen = of_find_node_by_path("/chosen@0");
505 
506 	DBG(" <- unflatten_device_tree()\n");
507 }
508 
509 /*
510  * ibm,pa-features is a per-cpu property that contains a string of
511  * attribute descriptors, each of which has a 2 byte header plus up
512  * to 254 bytes worth of processor attribute bits.  First header
513  * byte specifies the number of bytes following the header.
514  * Second header byte is an "attribute-specifier" type, of which
515  * zero is the only currently-defined value.
516  * Implementation:  Pass in the byte and bit offset for the feature
517  * that we are interested in.  The function will return -1 if the
518  * pa-features property is missing, or a 1/0 to indicate if the feature
519  * is supported/not supported.  Note that the bit numbers are
520  * big-endian to match the definition in PAPR.
521  */
522 static struct ibm_pa_feature {
523 	unsigned long	cpu_features;	/* CPU_FTR_xxx bit */
524 	unsigned int	cpu_user_ftrs;	/* PPC_FEATURE_xxx bit */
525 	unsigned char	pabyte;		/* byte number in ibm,pa-features */
526 	unsigned char	pabit;		/* bit number (big-endian) */
527 	unsigned char	invert;		/* if 1, pa bit set => clear feature */
528 } ibm_pa_features[] __initdata = {
529 	{0, PPC_FEATURE_HAS_MMU,	0, 0, 0},
530 	{0, PPC_FEATURE_HAS_FPU,	0, 1, 0},
531 	{CPU_FTR_SLB, 0,		0, 2, 0},
532 	{CPU_FTR_CTRL, 0,		0, 3, 0},
533 	{CPU_FTR_NOEXECUTE, 0,		0, 6, 0},
534 	{CPU_FTR_NODSISRALIGN, 0,	1, 1, 1},
535 #if 0
536 	/* put this back once we know how to test if firmware does 64k IO */
537 	{CPU_FTR_CI_LARGE_PAGE, 0,	1, 2, 0},
538 #endif
539 	{CPU_FTR_REAL_LE, PPC_FEATURE_TRUE_LE, 5, 0, 0},
540 };
541 
542 static void __init scan_features(unsigned long node, unsigned char *ftrs,
543 				 unsigned long tablelen,
544 				 struct ibm_pa_feature *fp,
545 				 unsigned long ft_size)
546 {
547 	unsigned long i, len, bit;
548 
549 	/* find descriptor with type == 0 */
550 	for (;;) {
551 		if (tablelen < 3)
552 			return;
553 		len = 2 + ftrs[0];
554 		if (tablelen < len)
555 			return;		/* descriptor 0 not found */
556 		if (ftrs[1] == 0)
557 			break;
558 		tablelen -= len;
559 		ftrs += len;
560 	}
561 
562 	/* loop over bits we know about */
563 	for (i = 0; i < ft_size; ++i, ++fp) {
564 		if (fp->pabyte >= ftrs[0])
565 			continue;
566 		bit = (ftrs[2 + fp->pabyte] >> (7 - fp->pabit)) & 1;
567 		if (bit ^ fp->invert) {
568 			cur_cpu_spec->cpu_features |= fp->cpu_features;
569 			cur_cpu_spec->cpu_user_features |= fp->cpu_user_ftrs;
570 		} else {
571 			cur_cpu_spec->cpu_features &= ~fp->cpu_features;
572 			cur_cpu_spec->cpu_user_features &= ~fp->cpu_user_ftrs;
573 		}
574 	}
575 }
576 
577 static void __init check_cpu_pa_features(unsigned long node)
578 {
579 	unsigned char *pa_ftrs;
580 	unsigned long tablelen;
581 
582 	pa_ftrs = of_get_flat_dt_prop(node, "ibm,pa-features", &tablelen);
583 	if (pa_ftrs == NULL)
584 		return;
585 
586 	scan_features(node, pa_ftrs, tablelen,
587 		      ibm_pa_features, ARRAY_SIZE(ibm_pa_features));
588 }
589 
590 static struct feature_property {
591 	const char *name;
592 	u32 min_value;
593 	unsigned long cpu_feature;
594 	unsigned long cpu_user_ftr;
595 } feature_properties[] __initdata = {
596 #ifdef CONFIG_ALTIVEC
597 	{"altivec", 0, CPU_FTR_ALTIVEC, PPC_FEATURE_HAS_ALTIVEC},
598 	{"ibm,vmx", 1, CPU_FTR_ALTIVEC, PPC_FEATURE_HAS_ALTIVEC},
599 #endif /* CONFIG_ALTIVEC */
600 #ifdef CONFIG_PPC64
601 	{"ibm,dfp", 1, 0, PPC_FEATURE_HAS_DFP},
602 	{"ibm,purr", 1, CPU_FTR_PURR, 0},
603 	{"ibm,spurr", 1, CPU_FTR_SPURR, 0},
604 #endif /* CONFIG_PPC64 */
605 };
606 
607 static void __init check_cpu_feature_properties(unsigned long node)
608 {
609 	unsigned long i;
610 	struct feature_property *fp = feature_properties;
611 	const u32 *prop;
612 
613 	for (i = 0; i < ARRAY_SIZE(feature_properties); ++i, ++fp) {
614 		prop = of_get_flat_dt_prop(node, fp->name, NULL);
615 		if (prop && *prop >= fp->min_value) {
616 			cur_cpu_spec->cpu_features |= fp->cpu_feature;
617 			cur_cpu_spec->cpu_user_features |= fp->cpu_user_ftr;
618 		}
619 	}
620 }
621 
622 static int __init early_init_dt_scan_cpus(unsigned long node,
623 					  const char *uname, int depth,
624 					  void *data)
625 {
626 	static int logical_cpuid = 0;
627 	char *type = of_get_flat_dt_prop(node, "device_type", NULL);
628 	const u32 *prop;
629 	const u32 *intserv;
630 	int i, nthreads;
631 	unsigned long len;
632 	int found = 0;
633 
634 	/* We are scanning "cpu" nodes only */
635 	if (type == NULL || strcmp(type, "cpu") != 0)
636 		return 0;
637 
638 	/* Get physical cpuid */
639 	intserv = of_get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s", &len);
640 	if (intserv) {
641 		nthreads = len / sizeof(int);
642 	} else {
643 		intserv = of_get_flat_dt_prop(node, "reg", NULL);
644 		nthreads = 1;
645 	}
646 
647 	/*
648 	 * Now see if any of these threads match our boot cpu.
649 	 * NOTE: This must match the parsing done in smp_setup_cpu_maps.
650 	 */
651 	for (i = 0; i < nthreads; i++) {
652 		/*
653 		 * version 2 of the kexec param format adds the phys cpuid of
654 		 * booted proc.
655 		 */
656 		if (initial_boot_params && initial_boot_params->version >= 2) {
657 			if (intserv[i] ==
658 					initial_boot_params->boot_cpuid_phys) {
659 				found = 1;
660 				break;
661 			}
662 		} else {
663 			/*
664 			 * Check if it's the boot-cpu, set it's hw index now,
665 			 * unfortunately this format did not support booting
666 			 * off secondary threads.
667 			 */
668 			if (of_get_flat_dt_prop(node,
669 					"linux,boot-cpu", NULL) != NULL) {
670 				found = 1;
671 				break;
672 			}
673 		}
674 
675 #ifdef CONFIG_SMP
676 		/* logical cpu id is always 0 on UP kernels */
677 		logical_cpuid++;
678 #endif
679 	}
680 
681 	if (found) {
682 		DBG("boot cpu: logical %d physical %d\n", logical_cpuid,
683 			intserv[i]);
684 		boot_cpuid = logical_cpuid;
685 		set_hard_smp_processor_id(boot_cpuid, intserv[i]);
686 
687 		/*
688 		 * PAPR defines "logical" PVR values for cpus that
689 		 * meet various levels of the architecture:
690 		 * 0x0f000001	Architecture version 2.04
691 		 * 0x0f000002	Architecture version 2.05
692 		 * If the cpu-version property in the cpu node contains
693 		 * such a value, we call identify_cpu again with the
694 		 * logical PVR value in order to use the cpu feature
695 		 * bits appropriate for the architecture level.
696 		 *
697 		 * A POWER6 partition in "POWER6 architected" mode
698 		 * uses the 0x0f000002 PVR value; in POWER5+ mode
699 		 * it uses 0x0f000001.
700 		 */
701 		prop = of_get_flat_dt_prop(node, "cpu-version", NULL);
702 		if (prop && (*prop & 0xff000000) == 0x0f000000)
703 			identify_cpu(0, *prop);
704 	}
705 
706 	check_cpu_feature_properties(node);
707 	check_cpu_pa_features(node);
708 
709 #ifdef CONFIG_PPC_PSERIES
710 	if (nthreads > 1)
711 		cur_cpu_spec->cpu_features |= CPU_FTR_SMT;
712 	else
713 		cur_cpu_spec->cpu_features &= ~CPU_FTR_SMT;
714 #endif
715 
716 	return 0;
717 }
718 
719 static int __init early_init_dt_scan_chosen(unsigned long node,
720 					    const char *uname, int depth, void *data)
721 {
722 	unsigned long *lprop;
723 	u32 *prop;
724 	unsigned long l;
725 	char *p;
726 
727 	DBG("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
728 
729 	if (depth != 1 ||
730 	    (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
731 		return 0;
732 
733 #ifdef CONFIG_PPC64
734 	/* check if iommu is forced on or off */
735 	if (of_get_flat_dt_prop(node, "linux,iommu-off", NULL) != NULL)
736 		iommu_is_off = 1;
737 	if (of_get_flat_dt_prop(node, "linux,iommu-force-on", NULL) != NULL)
738 		iommu_force_on = 1;
739 #endif
740 
741 	/* mem=x on the command line is the preferred mechanism */
742  	lprop = of_get_flat_dt_prop(node, "linux,memory-limit", NULL);
743  	if (lprop)
744  		memory_limit = *lprop;
745 
746 #ifdef CONFIG_PPC64
747  	lprop = of_get_flat_dt_prop(node, "linux,tce-alloc-start", NULL);
748  	if (lprop)
749  		tce_alloc_start = *lprop;
750  	lprop = of_get_flat_dt_prop(node, "linux,tce-alloc-end", NULL);
751  	if (lprop)
752  		tce_alloc_end = *lprop;
753 #endif
754 
755 #ifdef CONFIG_KEXEC
756        lprop = (u64*)of_get_flat_dt_prop(node, "linux,crashkernel-base", NULL);
757        if (lprop)
758                crashk_res.start = *lprop;
759 
760        lprop = (u64*)of_get_flat_dt_prop(node, "linux,crashkernel-size", NULL);
761        if (lprop)
762                crashk_res.end = crashk_res.start + *lprop - 1;
763 #endif
764 
765 #ifdef CONFIG_BLK_DEV_INITRD
766 	DBG("Looking for initrd properties... ");
767 	prop = of_get_flat_dt_prop(node, "linux,initrd-start", &l);
768 	if (prop) {
769 		initrd_start = (unsigned long)__va(of_read_ulong(prop, l/4));
770 		prop = of_get_flat_dt_prop(node, "linux,initrd-end", &l);
771 		if (prop) {
772 			initrd_end = (unsigned long)__va(of_read_ulong(prop, l/4));
773 			initrd_below_start_ok = 1;
774 		} else {
775 			initrd_start = 0;
776 		}
777 	}
778 	DBG("initrd_start=0x%lx  initrd_end=0x%lx\n", initrd_start, initrd_end);
779 #endif /* CONFIG_BLK_DEV_INITRD */
780 
781 	/* Retreive command line */
782  	p = of_get_flat_dt_prop(node, "bootargs", &l);
783 	if (p != NULL && l > 0)
784 		strlcpy(cmd_line, p, min((int)l, COMMAND_LINE_SIZE));
785 
786 #ifdef CONFIG_CMDLINE
787 	if (p == NULL || l == 0 || (l == 1 && (*p) == 0))
788 		strlcpy(cmd_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
789 #endif /* CONFIG_CMDLINE */
790 
791 	DBG("Command line is: %s\n", cmd_line);
792 
793 	/* break now */
794 	return 1;
795 }
796 
797 static int __init early_init_dt_scan_root(unsigned long node,
798 					  const char *uname, int depth, void *data)
799 {
800 	u32 *prop;
801 
802 	if (depth != 0)
803 		return 0;
804 
805 	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
806 	dt_root_size_cells = (prop == NULL) ? 1 : *prop;
807 	DBG("dt_root_size_cells = %x\n", dt_root_size_cells);
808 
809 	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
810 	dt_root_addr_cells = (prop == NULL) ? 2 : *prop;
811 	DBG("dt_root_addr_cells = %x\n", dt_root_addr_cells);
812 
813 	/* break now */
814 	return 1;
815 }
816 
817 static unsigned long __init dt_mem_next_cell(int s, cell_t **cellp)
818 {
819 	cell_t *p = *cellp;
820 
821 	*cellp = p + s;
822 	return of_read_ulong(p, s);
823 }
824 
825 #ifdef CONFIG_PPC_PSERIES
826 /*
827  * Interpret the ibm,dynamic-memory property in the
828  * /ibm,dynamic-reconfiguration-memory node.
829  * This contains a list of memory blocks along with NUMA affinity
830  * information.
831  */
832 static int __init early_init_dt_scan_drconf_memory(unsigned long node)
833 {
834 	cell_t *dm, *ls;
835 	unsigned long l, n;
836 	unsigned long base, size, lmb_size, flags;
837 
838 	ls = (cell_t *)of_get_flat_dt_prop(node, "ibm,lmb-size", &l);
839 	if (ls == NULL || l < dt_root_size_cells * sizeof(cell_t))
840 		return 0;
841 	lmb_size = dt_mem_next_cell(dt_root_size_cells, &ls);
842 
843 	dm = (cell_t *)of_get_flat_dt_prop(node, "ibm,dynamic-memory", &l);
844 	if (dm == NULL || l < sizeof(cell_t))
845 		return 0;
846 
847 	n = *dm++;	/* number of entries */
848 	if (l < (n * (dt_root_addr_cells + 4) + 1) * sizeof(cell_t))
849 		return 0;
850 
851 	for (; n != 0; --n) {
852 		base = dt_mem_next_cell(dt_root_addr_cells, &dm);
853 		flags = dm[3];
854 		/* skip DRC index, pad, assoc. list index, flags */
855 		dm += 4;
856 		/* skip this block if the reserved bit is set in flags (0x80)
857 		   or if the block is not assigned to this partition (0x8) */
858 		if ((flags & 0x80) || !(flags & 0x8))
859 			continue;
860 		size = lmb_size;
861 		if (iommu_is_off) {
862 			if (base >= 0x80000000ul)
863 				continue;
864 			if ((base + size) > 0x80000000ul)
865 				size = 0x80000000ul - base;
866 		}
867 		lmb_add(base, size);
868 	}
869 	lmb_dump_all();
870 	return 0;
871 }
872 #else
873 #define early_init_dt_scan_drconf_memory(node)	0
874 #endif /* CONFIG_PPC_PSERIES */
875 
876 static int __init early_init_dt_scan_memory(unsigned long node,
877 					    const char *uname, int depth, void *data)
878 {
879 	char *type = of_get_flat_dt_prop(node, "device_type", NULL);
880 	cell_t *reg, *endp;
881 	unsigned long l;
882 
883 	/* Look for the ibm,dynamic-reconfiguration-memory node */
884 	if (depth == 1 &&
885 	    strcmp(uname, "ibm,dynamic-reconfiguration-memory") == 0)
886 		return early_init_dt_scan_drconf_memory(node);
887 
888 	/* We are scanning "memory" nodes only */
889 	if (type == NULL) {
890 		/*
891 		 * The longtrail doesn't have a device_type on the
892 		 * /memory node, so look for the node called /memory@0.
893 		 */
894 		if (depth != 1 || strcmp(uname, "memory@0") != 0)
895 			return 0;
896 	} else if (strcmp(type, "memory") != 0)
897 		return 0;
898 
899 	reg = (cell_t *)of_get_flat_dt_prop(node, "linux,usable-memory", &l);
900 	if (reg == NULL)
901 		reg = (cell_t *)of_get_flat_dt_prop(node, "reg", &l);
902 	if (reg == NULL)
903 		return 0;
904 
905 	endp = reg + (l / sizeof(cell_t));
906 
907 	DBG("memory scan node %s, reg size %ld, data: %x %x %x %x,\n",
908 	    uname, l, reg[0], reg[1], reg[2], reg[3]);
909 
910 	while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
911 		unsigned long base, size;
912 
913 		base = dt_mem_next_cell(dt_root_addr_cells, &reg);
914 		size = dt_mem_next_cell(dt_root_size_cells, &reg);
915 
916 		if (size == 0)
917 			continue;
918 		DBG(" - %lx ,  %lx\n", base, size);
919 #ifdef CONFIG_PPC64
920 		if (iommu_is_off) {
921 			if (base >= 0x80000000ul)
922 				continue;
923 			if ((base + size) > 0x80000000ul)
924 				size = 0x80000000ul - base;
925 		}
926 #endif
927 		lmb_add(base, size);
928 	}
929 	return 0;
930 }
931 
932 static void __init early_reserve_mem(void)
933 {
934 	u64 base, size;
935 	u64 *reserve_map;
936 	unsigned long self_base;
937 	unsigned long self_size;
938 
939 	reserve_map = (u64 *)(((unsigned long)initial_boot_params) +
940 					initial_boot_params->off_mem_rsvmap);
941 
942 	/* before we do anything, lets reserve the dt blob */
943 	self_base = __pa((unsigned long)initial_boot_params);
944 	self_size = initial_boot_params->totalsize;
945 	lmb_reserve(self_base, self_size);
946 
947 #ifdef CONFIG_BLK_DEV_INITRD
948 	/* then reserve the initrd, if any */
949 	if (initrd_start && (initrd_end > initrd_start))
950 		lmb_reserve(__pa(initrd_start), initrd_end - initrd_start);
951 #endif /* CONFIG_BLK_DEV_INITRD */
952 
953 #ifdef CONFIG_PPC32
954 	/*
955 	 * Handle the case where we might be booting from an old kexec
956 	 * image that setup the mem_rsvmap as pairs of 32-bit values
957 	 */
958 	if (*reserve_map > 0xffffffffull) {
959 		u32 base_32, size_32;
960 		u32 *reserve_map_32 = (u32 *)reserve_map;
961 
962 		while (1) {
963 			base_32 = *(reserve_map_32++);
964 			size_32 = *(reserve_map_32++);
965 			if (size_32 == 0)
966 				break;
967 			/* skip if the reservation is for the blob */
968 			if (base_32 == self_base && size_32 == self_size)
969 				continue;
970 			DBG("reserving: %x -> %x\n", base_32, size_32);
971 			lmb_reserve(base_32, size_32);
972 		}
973 		return;
974 	}
975 #endif
976 	while (1) {
977 		base = *(reserve_map++);
978 		size = *(reserve_map++);
979 		if (size == 0)
980 			break;
981 		DBG("reserving: %llx -> %llx\n", base, size);
982 		lmb_reserve(base, size);
983 	}
984 
985 #if 0
986 	DBG("memory reserved, lmbs :\n");
987       	lmb_dump_all();
988 #endif
989 }
990 
991 void __init early_init_devtree(void *params)
992 {
993 	DBG(" -> early_init_devtree()\n");
994 
995 	/* Setup flat device-tree pointer */
996 	initial_boot_params = params;
997 
998 #ifdef CONFIG_PPC_RTAS
999 	/* Some machines might need RTAS info for debugging, grab it now. */
1000 	of_scan_flat_dt(early_init_dt_scan_rtas, NULL);
1001 #endif
1002 
1003 	/* Retrieve various informations from the /chosen node of the
1004 	 * device-tree, including the platform type, initrd location and
1005 	 * size, TCE reserve, and more ...
1006 	 */
1007 	of_scan_flat_dt(early_init_dt_scan_chosen, NULL);
1008 
1009 	/* Scan memory nodes and rebuild LMBs */
1010 	lmb_init();
1011 	of_scan_flat_dt(early_init_dt_scan_root, NULL);
1012 	of_scan_flat_dt(early_init_dt_scan_memory, NULL);
1013 
1014 	/* Save command line for /proc/cmdline and then parse parameters */
1015 	strlcpy(boot_command_line, cmd_line, COMMAND_LINE_SIZE);
1016 	parse_early_param();
1017 
1018 	/* Reserve LMB regions used by kernel, initrd, dt, etc... */
1019 	lmb_reserve(PHYSICAL_START, __pa(klimit) - PHYSICAL_START);
1020 	reserve_kdump_trampoline();
1021 	reserve_crashkernel();
1022 	early_reserve_mem();
1023 
1024 	lmb_enforce_memory_limit(memory_limit);
1025 	lmb_analyze();
1026 
1027 	DBG("Phys. mem: %lx\n", lmb_phys_mem_size());
1028 
1029 	/* We may need to relocate the flat tree, do it now.
1030 	 * FIXME .. and the initrd too? */
1031 	move_device_tree();
1032 
1033 	DBG("Scanning CPUs ...\n");
1034 
1035 	/* Retreive CPU related informations from the flat tree
1036 	 * (altivec support, boot CPU ID, ...)
1037 	 */
1038 	of_scan_flat_dt(early_init_dt_scan_cpus, NULL);
1039 
1040 	DBG(" <- early_init_devtree()\n");
1041 }
1042 
1043 #undef printk
1044 
1045 int of_n_addr_cells(struct device_node* np)
1046 {
1047 	const int *ip;
1048 	do {
1049 		if (np->parent)
1050 			np = np->parent;
1051 		ip = of_get_property(np, "#address-cells", NULL);
1052 		if (ip != NULL)
1053 			return *ip;
1054 	} while (np->parent);
1055 	/* No #address-cells property for the root node, default to 1 */
1056 	return 1;
1057 }
1058 EXPORT_SYMBOL(of_n_addr_cells);
1059 
1060 int of_n_size_cells(struct device_node* np)
1061 {
1062 	const int* ip;
1063 	do {
1064 		if (np->parent)
1065 			np = np->parent;
1066 		ip = of_get_property(np, "#size-cells", NULL);
1067 		if (ip != NULL)
1068 			return *ip;
1069 	} while (np->parent);
1070 	/* No #size-cells property for the root node, default to 1 */
1071 	return 1;
1072 }
1073 EXPORT_SYMBOL(of_n_size_cells);
1074 
1075 /** Checks if the given "compat" string matches one of the strings in
1076  * the device's "compatible" property
1077  */
1078 int of_device_is_compatible(const struct device_node *device,
1079 		const char *compat)
1080 {
1081 	const char* cp;
1082 	int cplen, l;
1083 
1084 	cp = of_get_property(device, "compatible", &cplen);
1085 	if (cp == NULL)
1086 		return 0;
1087 	while (cplen > 0) {
1088 		if (strncasecmp(cp, compat, strlen(compat)) == 0)
1089 			return 1;
1090 		l = strlen(cp) + 1;
1091 		cp += l;
1092 		cplen -= l;
1093 	}
1094 
1095 	return 0;
1096 }
1097 EXPORT_SYMBOL(of_device_is_compatible);
1098 
1099 
1100 /**
1101  * Indicates whether the root node has a given value in its
1102  * compatible property.
1103  */
1104 int machine_is_compatible(const char *compat)
1105 {
1106 	struct device_node *root;
1107 	int rc = 0;
1108 
1109 	root = of_find_node_by_path("/");
1110 	if (root) {
1111 		rc = of_device_is_compatible(root, compat);
1112 		of_node_put(root);
1113 	}
1114 	return rc;
1115 }
1116 EXPORT_SYMBOL(machine_is_compatible);
1117 
1118 /*******
1119  *
1120  * New implementation of the OF "find" APIs, return a refcounted
1121  * object, call of_node_put() when done.  The device tree and list
1122  * are protected by a rw_lock.
1123  *
1124  * Note that property management will need some locking as well,
1125  * this isn't dealt with yet.
1126  *
1127  *******/
1128 
1129 /**
1130  *	of_find_node_by_name - Find a node by its "name" property
1131  *	@from:	The node to start searching from or NULL, the node
1132  *		you pass will not be searched, only the next one
1133  *		will; typically, you pass what the previous call
1134  *		returned. of_node_put() will be called on it
1135  *	@name:	The name string to match against
1136  *
1137  *	Returns a node pointer with refcount incremented, use
1138  *	of_node_put() on it when done.
1139  */
1140 struct device_node *of_find_node_by_name(struct device_node *from,
1141 	const char *name)
1142 {
1143 	struct device_node *np;
1144 
1145 	read_lock(&devtree_lock);
1146 	np = from ? from->allnext : allnodes;
1147 	for (; np != NULL; np = np->allnext)
1148 		if (np->name != NULL && strcasecmp(np->name, name) == 0
1149 		    && of_node_get(np))
1150 			break;
1151 	of_node_put(from);
1152 	read_unlock(&devtree_lock);
1153 	return np;
1154 }
1155 EXPORT_SYMBOL(of_find_node_by_name);
1156 
1157 /**
1158  *	of_find_node_by_type - Find a node by its "device_type" property
1159  *	@from:	The node to start searching from or NULL, the node
1160  *		you pass will not be searched, only the next one
1161  *		will; typically, you pass what the previous call
1162  *		returned. of_node_put() will be called on it
1163  *	@name:	The type string to match against
1164  *
1165  *	Returns a node pointer with refcount incremented, use
1166  *	of_node_put() on it when done.
1167  */
1168 struct device_node *of_find_node_by_type(struct device_node *from,
1169 	const char *type)
1170 {
1171 	struct device_node *np;
1172 
1173 	read_lock(&devtree_lock);
1174 	np = from ? from->allnext : allnodes;
1175 	for (; np != 0; np = np->allnext)
1176 		if (np->type != 0 && strcasecmp(np->type, type) == 0
1177 		    && of_node_get(np))
1178 			break;
1179 	of_node_put(from);
1180 	read_unlock(&devtree_lock);
1181 	return np;
1182 }
1183 EXPORT_SYMBOL(of_find_node_by_type);
1184 
1185 /**
1186  *	of_find_compatible_node - Find a node based on type and one of the
1187  *                                tokens in its "compatible" property
1188  *	@from:		The node to start searching from or NULL, the node
1189  *			you pass will not be searched, only the next one
1190  *			will; typically, you pass what the previous call
1191  *			returned. of_node_put() will be called on it
1192  *	@type:		The type string to match "device_type" or NULL to ignore
1193  *	@compatible:	The string to match to one of the tokens in the device
1194  *			"compatible" list.
1195  *
1196  *	Returns a node pointer with refcount incremented, use
1197  *	of_node_put() on it when done.
1198  */
1199 struct device_node *of_find_compatible_node(struct device_node *from,
1200 	const char *type, const char *compatible)
1201 {
1202 	struct device_node *np;
1203 
1204 	read_lock(&devtree_lock);
1205 	np = from ? from->allnext : allnodes;
1206 	for (; np != 0; np = np->allnext) {
1207 		if (type != NULL
1208 		    && !(np->type != 0 && strcasecmp(np->type, type) == 0))
1209 			continue;
1210 		if (of_device_is_compatible(np, compatible) && of_node_get(np))
1211 			break;
1212 	}
1213 	of_node_put(from);
1214 	read_unlock(&devtree_lock);
1215 	return np;
1216 }
1217 EXPORT_SYMBOL(of_find_compatible_node);
1218 
1219 /**
1220  *	of_find_node_by_path - Find a node matching a full OF path
1221  *	@path:	The full path to match
1222  *
1223  *	Returns a node pointer with refcount incremented, use
1224  *	of_node_put() on it when done.
1225  */
1226 struct device_node *of_find_node_by_path(const char *path)
1227 {
1228 	struct device_node *np = allnodes;
1229 
1230 	read_lock(&devtree_lock);
1231 	for (; np != 0; np = np->allnext) {
1232 		if (np->full_name != 0 && strcasecmp(np->full_name, path) == 0
1233 		    && of_node_get(np))
1234 			break;
1235 	}
1236 	read_unlock(&devtree_lock);
1237 	return np;
1238 }
1239 EXPORT_SYMBOL(of_find_node_by_path);
1240 
1241 /**
1242  *	of_find_node_by_phandle - Find a node given a phandle
1243  *	@handle:	phandle of the node to find
1244  *
1245  *	Returns a node pointer with refcount incremented, use
1246  *	of_node_put() on it when done.
1247  */
1248 struct device_node *of_find_node_by_phandle(phandle handle)
1249 {
1250 	struct device_node *np;
1251 
1252 	read_lock(&devtree_lock);
1253 	for (np = allnodes; np != 0; np = np->allnext)
1254 		if (np->linux_phandle == handle)
1255 			break;
1256 	of_node_get(np);
1257 	read_unlock(&devtree_lock);
1258 	return np;
1259 }
1260 EXPORT_SYMBOL(of_find_node_by_phandle);
1261 
1262 /**
1263  *	of_find_all_nodes - Get next node in global list
1264  *	@prev:	Previous node or NULL to start iteration
1265  *		of_node_put() will be called on it
1266  *
1267  *	Returns a node pointer with refcount incremented, use
1268  *	of_node_put() on it when done.
1269  */
1270 struct device_node *of_find_all_nodes(struct device_node *prev)
1271 {
1272 	struct device_node *np;
1273 
1274 	read_lock(&devtree_lock);
1275 	np = prev ? prev->allnext : allnodes;
1276 	for (; np != 0; np = np->allnext)
1277 		if (of_node_get(np))
1278 			break;
1279 	of_node_put(prev);
1280 	read_unlock(&devtree_lock);
1281 	return np;
1282 }
1283 EXPORT_SYMBOL(of_find_all_nodes);
1284 
1285 /**
1286  *	of_get_parent - Get a node's parent if any
1287  *	@node:	Node to get parent
1288  *
1289  *	Returns a node pointer with refcount incremented, use
1290  *	of_node_put() on it when done.
1291  */
1292 struct device_node *of_get_parent(const struct device_node *node)
1293 {
1294 	struct device_node *np;
1295 
1296 	if (!node)
1297 		return NULL;
1298 
1299 	read_lock(&devtree_lock);
1300 	np = of_node_get(node->parent);
1301 	read_unlock(&devtree_lock);
1302 	return np;
1303 }
1304 EXPORT_SYMBOL(of_get_parent);
1305 
1306 /**
1307  *	of_get_next_child - Iterate a node childs
1308  *	@node:	parent node
1309  *	@prev:	previous child of the parent node, or NULL to get first
1310  *
1311  *	Returns a node pointer with refcount incremented, use
1312  *	of_node_put() on it when done.
1313  */
1314 struct device_node *of_get_next_child(const struct device_node *node,
1315 	struct device_node *prev)
1316 {
1317 	struct device_node *next;
1318 
1319 	read_lock(&devtree_lock);
1320 	next = prev ? prev->sibling : node->child;
1321 	for (; next != 0; next = next->sibling)
1322 		if (of_node_get(next))
1323 			break;
1324 	of_node_put(prev);
1325 	read_unlock(&devtree_lock);
1326 	return next;
1327 }
1328 EXPORT_SYMBOL(of_get_next_child);
1329 
1330 /**
1331  *	of_node_get - Increment refcount of a node
1332  *	@node:	Node to inc refcount, NULL is supported to
1333  *		simplify writing of callers
1334  *
1335  *	Returns node.
1336  */
1337 struct device_node *of_node_get(struct device_node *node)
1338 {
1339 	if (node)
1340 		kref_get(&node->kref);
1341 	return node;
1342 }
1343 EXPORT_SYMBOL(of_node_get);
1344 
1345 static inline struct device_node * kref_to_device_node(struct kref *kref)
1346 {
1347 	return container_of(kref, struct device_node, kref);
1348 }
1349 
1350 /**
1351  *	of_node_release - release a dynamically allocated node
1352  *	@kref:  kref element of the node to be released
1353  *
1354  *	In of_node_put() this function is passed to kref_put()
1355  *	as the destructor.
1356  */
1357 static void of_node_release(struct kref *kref)
1358 {
1359 	struct device_node *node = kref_to_device_node(kref);
1360 	struct property *prop = node->properties;
1361 
1362 	if (!OF_IS_DYNAMIC(node))
1363 		return;
1364 	while (prop) {
1365 		struct property *next = prop->next;
1366 		kfree(prop->name);
1367 		kfree(prop->value);
1368 		kfree(prop);
1369 		prop = next;
1370 
1371 		if (!prop) {
1372 			prop = node->deadprops;
1373 			node->deadprops = NULL;
1374 		}
1375 	}
1376 	kfree(node->full_name);
1377 	kfree(node->data);
1378 	kfree(node);
1379 }
1380 
1381 /**
1382  *	of_node_put - Decrement refcount of a node
1383  *	@node:	Node to dec refcount, NULL is supported to
1384  *		simplify writing of callers
1385  *
1386  */
1387 void of_node_put(struct device_node *node)
1388 {
1389 	if (node)
1390 		kref_put(&node->kref, of_node_release);
1391 }
1392 EXPORT_SYMBOL(of_node_put);
1393 
1394 /*
1395  * Plug a device node into the tree and global list.
1396  */
1397 void of_attach_node(struct device_node *np)
1398 {
1399 	write_lock(&devtree_lock);
1400 	np->sibling = np->parent->child;
1401 	np->allnext = allnodes;
1402 	np->parent->child = np;
1403 	allnodes = np;
1404 	write_unlock(&devtree_lock);
1405 }
1406 
1407 /*
1408  * "Unplug" a node from the device tree.  The caller must hold
1409  * a reference to the node.  The memory associated with the node
1410  * is not freed until its refcount goes to zero.
1411  */
1412 void of_detach_node(const struct device_node *np)
1413 {
1414 	struct device_node *parent;
1415 
1416 	write_lock(&devtree_lock);
1417 
1418 	parent = np->parent;
1419 
1420 	if (allnodes == np)
1421 		allnodes = np->allnext;
1422 	else {
1423 		struct device_node *prev;
1424 		for (prev = allnodes;
1425 		     prev->allnext != np;
1426 		     prev = prev->allnext)
1427 			;
1428 		prev->allnext = np->allnext;
1429 	}
1430 
1431 	if (parent->child == np)
1432 		parent->child = np->sibling;
1433 	else {
1434 		struct device_node *prevsib;
1435 		for (prevsib = np->parent->child;
1436 		     prevsib->sibling != np;
1437 		     prevsib = prevsib->sibling)
1438 			;
1439 		prevsib->sibling = np->sibling;
1440 	}
1441 
1442 	write_unlock(&devtree_lock);
1443 }
1444 
1445 #ifdef CONFIG_PPC_PSERIES
1446 /*
1447  * Fix up the uninitialized fields in a new device node:
1448  * name, type and pci-specific fields
1449  */
1450 
1451 static int of_finish_dynamic_node(struct device_node *node)
1452 {
1453 	struct device_node *parent = of_get_parent(node);
1454 	int err = 0;
1455 	const phandle *ibm_phandle;
1456 
1457 	node->name = of_get_property(node, "name", NULL);
1458 	node->type = of_get_property(node, "device_type", NULL);
1459 
1460 	if (!parent) {
1461 		err = -ENODEV;
1462 		goto out;
1463 	}
1464 
1465 	/* We don't support that function on PowerMac, at least
1466 	 * not yet
1467 	 */
1468 	if (machine_is(powermac))
1469 		return -ENODEV;
1470 
1471 	/* fix up new node's linux_phandle field */
1472 	if ((ibm_phandle = of_get_property(node, "ibm,phandle", NULL)))
1473 		node->linux_phandle = *ibm_phandle;
1474 
1475 out:
1476 	of_node_put(parent);
1477 	return err;
1478 }
1479 
1480 static int prom_reconfig_notifier(struct notifier_block *nb,
1481 				  unsigned long action, void *node)
1482 {
1483 	int err;
1484 
1485 	switch (action) {
1486 	case PSERIES_RECONFIG_ADD:
1487 		err = of_finish_dynamic_node(node);
1488 		if (err < 0) {
1489 			printk(KERN_ERR "finish_node returned %d\n", err);
1490 			err = NOTIFY_BAD;
1491 		}
1492 		break;
1493 	default:
1494 		err = NOTIFY_DONE;
1495 		break;
1496 	}
1497 	return err;
1498 }
1499 
1500 static struct notifier_block prom_reconfig_nb = {
1501 	.notifier_call = prom_reconfig_notifier,
1502 	.priority = 10, /* This one needs to run first */
1503 };
1504 
1505 static int __init prom_reconfig_setup(void)
1506 {
1507 	return pSeries_reconfig_notifier_register(&prom_reconfig_nb);
1508 }
1509 __initcall(prom_reconfig_setup);
1510 #endif
1511 
1512 struct property *of_find_property(const struct device_node *np,
1513 				  const char *name,
1514 				  int *lenp)
1515 {
1516 	struct property *pp;
1517 
1518 	read_lock(&devtree_lock);
1519 	for (pp = np->properties; pp != 0; pp = pp->next)
1520 		if (strcmp(pp->name, name) == 0) {
1521 			if (lenp != 0)
1522 				*lenp = pp->length;
1523 			break;
1524 		}
1525 	read_unlock(&devtree_lock);
1526 
1527 	return pp;
1528 }
1529 EXPORT_SYMBOL(of_find_property);
1530 
1531 /*
1532  * Find a property with a given name for a given node
1533  * and return the value.
1534  */
1535 const void *of_get_property(const struct device_node *np, const char *name,
1536 			 int *lenp)
1537 {
1538 	struct property *pp = of_find_property(np,name,lenp);
1539 	return pp ? pp->value : NULL;
1540 }
1541 EXPORT_SYMBOL(of_get_property);
1542 
1543 /*
1544  * Add a property to a node
1545  */
1546 int prom_add_property(struct device_node* np, struct property* prop)
1547 {
1548 	struct property **next;
1549 
1550 	prop->next = NULL;
1551 	write_lock(&devtree_lock);
1552 	next = &np->properties;
1553 	while (*next) {
1554 		if (strcmp(prop->name, (*next)->name) == 0) {
1555 			/* duplicate ! don't insert it */
1556 			write_unlock(&devtree_lock);
1557 			return -1;
1558 		}
1559 		next = &(*next)->next;
1560 	}
1561 	*next = prop;
1562 	write_unlock(&devtree_lock);
1563 
1564 #ifdef CONFIG_PROC_DEVICETREE
1565 	/* try to add to proc as well if it was initialized */
1566 	if (np->pde)
1567 		proc_device_tree_add_prop(np->pde, prop);
1568 #endif /* CONFIG_PROC_DEVICETREE */
1569 
1570 	return 0;
1571 }
1572 
1573 /*
1574  * Remove a property from a node.  Note that we don't actually
1575  * remove it, since we have given out who-knows-how-many pointers
1576  * to the data using get-property.  Instead we just move the property
1577  * to the "dead properties" list, so it won't be found any more.
1578  */
1579 int prom_remove_property(struct device_node *np, struct property *prop)
1580 {
1581 	struct property **next;
1582 	int found = 0;
1583 
1584 	write_lock(&devtree_lock);
1585 	next = &np->properties;
1586 	while (*next) {
1587 		if (*next == prop) {
1588 			/* found the node */
1589 			*next = prop->next;
1590 			prop->next = np->deadprops;
1591 			np->deadprops = prop;
1592 			found = 1;
1593 			break;
1594 		}
1595 		next = &(*next)->next;
1596 	}
1597 	write_unlock(&devtree_lock);
1598 
1599 	if (!found)
1600 		return -ENODEV;
1601 
1602 #ifdef CONFIG_PROC_DEVICETREE
1603 	/* try to remove the proc node as well */
1604 	if (np->pde)
1605 		proc_device_tree_remove_prop(np->pde, prop);
1606 #endif /* CONFIG_PROC_DEVICETREE */
1607 
1608 	return 0;
1609 }
1610 
1611 /*
1612  * Update a property in a node.  Note that we don't actually
1613  * remove it, since we have given out who-knows-how-many pointers
1614  * to the data using get-property.  Instead we just move the property
1615  * to the "dead properties" list, and add the new property to the
1616  * property list
1617  */
1618 int prom_update_property(struct device_node *np,
1619 			 struct property *newprop,
1620 			 struct property *oldprop)
1621 {
1622 	struct property **next;
1623 	int found = 0;
1624 
1625 	write_lock(&devtree_lock);
1626 	next = &np->properties;
1627 	while (*next) {
1628 		if (*next == oldprop) {
1629 			/* found the node */
1630 			newprop->next = oldprop->next;
1631 			*next = newprop;
1632 			oldprop->next = np->deadprops;
1633 			np->deadprops = oldprop;
1634 			found = 1;
1635 			break;
1636 		}
1637 		next = &(*next)->next;
1638 	}
1639 	write_unlock(&devtree_lock);
1640 
1641 	if (!found)
1642 		return -ENODEV;
1643 
1644 #ifdef CONFIG_PROC_DEVICETREE
1645 	/* try to add to proc as well if it was initialized */
1646 	if (np->pde)
1647 		proc_device_tree_update_prop(np->pde, newprop, oldprop);
1648 #endif /* CONFIG_PROC_DEVICETREE */
1649 
1650 	return 0;
1651 }
1652 
1653 
1654 /* Find the device node for a given logical cpu number, also returns the cpu
1655  * local thread number (index in ibm,interrupt-server#s) if relevant and
1656  * asked for (non NULL)
1657  */
1658 struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
1659 {
1660 	int hardid;
1661 	struct device_node *np;
1662 
1663 	hardid = get_hard_smp_processor_id(cpu);
1664 
1665 	for_each_node_by_type(np, "cpu") {
1666 		const u32 *intserv;
1667 		unsigned int plen, t;
1668 
1669 		/* Check for ibm,ppc-interrupt-server#s. If it doesn't exist
1670 		 * fallback to "reg" property and assume no threads
1671 		 */
1672 		intserv = of_get_property(np, "ibm,ppc-interrupt-server#s",
1673 				&plen);
1674 		if (intserv == NULL) {
1675 			const u32 *reg = of_get_property(np, "reg", NULL);
1676 			if (reg == NULL)
1677 				continue;
1678 			if (*reg == hardid) {
1679 				if (thread)
1680 					*thread = 0;
1681 				return np;
1682 			}
1683 		} else {
1684 			plen /= sizeof(u32);
1685 			for (t = 0; t < plen; t++) {
1686 				if (hardid == intserv[t]) {
1687 					if (thread)
1688 						*thread = t;
1689 					return np;
1690 				}
1691 			}
1692 		}
1693 	}
1694 	return NULL;
1695 }
1696 EXPORT_SYMBOL(of_get_cpu_node);
1697 
1698 #ifdef DEBUG
1699 static struct debugfs_blob_wrapper flat_dt_blob;
1700 
1701 static int __init export_flat_device_tree(void)
1702 {
1703 	struct dentry *d;
1704 
1705 	d = debugfs_create_dir("powerpc", NULL);
1706 	if (!d)
1707 		return 1;
1708 
1709 	flat_dt_blob.data = initial_boot_params;
1710 	flat_dt_blob.size = initial_boot_params->totalsize;
1711 
1712 	d = debugfs_create_blob("flat-device-tree", S_IFREG | S_IRUSR,
1713 				d, &flat_dt_blob);
1714 	if (!d)
1715 		return 1;
1716 
1717 	return 0;
1718 }
1719 __initcall(export_flat_device_tree);
1720 #endif
1721