xref: /linux/arch/powerpc/kernel/prom.c (revision 4949009eb8d40a441dcddcd96e101e77d31cf1b2)
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/export.h>
31 #include <linux/kexec.h>
32 #include <linux/irq.h>
33 #include <linux/memblock.h>
34 #include <linux/of.h>
35 #include <linux/of_fdt.h>
36 #include <linux/libfdt.h>
37 
38 #include <asm/prom.h>
39 #include <asm/rtas.h>
40 #include <asm/page.h>
41 #include <asm/processor.h>
42 #include <asm/irq.h>
43 #include <asm/io.h>
44 #include <asm/kdump.h>
45 #include <asm/smp.h>
46 #include <asm/mmu.h>
47 #include <asm/paca.h>
48 #include <asm/pgtable.h>
49 #include <asm/pci.h>
50 #include <asm/iommu.h>
51 #include <asm/btext.h>
52 #include <asm/sections.h>
53 #include <asm/machdep.h>
54 #include <asm/pci-bridge.h>
55 #include <asm/kexec.h>
56 #include <asm/opal.h>
57 #include <asm/fadump.h>
58 #include <asm/debug.h>
59 
60 #include <mm/mmu_decl.h>
61 
62 #ifdef DEBUG
63 #define DBG(fmt...) printk(KERN_ERR fmt)
64 #else
65 #define DBG(fmt...)
66 #endif
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 u64 ppc64_rma_size;
73 #endif
74 static phys_addr_t first_memblock_size;
75 static int __initdata boot_cpu_count;
76 
77 static int __init early_parse_mem(char *p)
78 {
79 	if (!p)
80 		return 1;
81 
82 	memory_limit = PAGE_ALIGN(memparse(p, &p));
83 	DBG("memory limit = 0x%llx\n", memory_limit);
84 
85 	return 0;
86 }
87 early_param("mem", early_parse_mem);
88 
89 /*
90  * overlaps_initrd - check for overlap with page aligned extension of
91  * initrd.
92  */
93 static inline int overlaps_initrd(unsigned long start, unsigned long size)
94 {
95 #ifdef CONFIG_BLK_DEV_INITRD
96 	if (!initrd_start)
97 		return 0;
98 
99 	return	(start + size) > _ALIGN_DOWN(initrd_start, PAGE_SIZE) &&
100 			start <= _ALIGN_UP(initrd_end, PAGE_SIZE);
101 #else
102 	return 0;
103 #endif
104 }
105 
106 /**
107  * move_device_tree - move tree to an unused area, if needed.
108  *
109  * The device tree may be allocated beyond our memory limit, or inside the
110  * crash kernel region for kdump, or within the page aligned range of initrd.
111  * If so, move it out of the way.
112  */
113 static void __init move_device_tree(void)
114 {
115 	unsigned long start, size;
116 	void *p;
117 
118 	DBG("-> move_device_tree\n");
119 
120 	start = __pa(initial_boot_params);
121 	size = fdt_totalsize(initial_boot_params);
122 
123 	if ((memory_limit && (start + size) > PHYSICAL_START + memory_limit) ||
124 			overlaps_crashkernel(start, size) ||
125 			overlaps_initrd(start, size)) {
126 		p = __va(memblock_alloc(size, PAGE_SIZE));
127 		memcpy(p, initial_boot_params, size);
128 		initial_boot_params = p;
129 		DBG("Moved device tree to 0x%p\n", p);
130 	}
131 
132 	DBG("<- move_device_tree\n");
133 }
134 
135 /*
136  * ibm,pa-features is a per-cpu property that contains a string of
137  * attribute descriptors, each of which has a 2 byte header plus up
138  * to 254 bytes worth of processor attribute bits.  First header
139  * byte specifies the number of bytes following the header.
140  * Second header byte is an "attribute-specifier" type, of which
141  * zero is the only currently-defined value.
142  * Implementation:  Pass in the byte and bit offset for the feature
143  * that we are interested in.  The function will return -1 if the
144  * pa-features property is missing, or a 1/0 to indicate if the feature
145  * is supported/not supported.  Note that the bit numbers are
146  * big-endian to match the definition in PAPR.
147  */
148 static struct ibm_pa_feature {
149 	unsigned long	cpu_features;	/* CPU_FTR_xxx bit */
150 	unsigned long	mmu_features;	/* MMU_FTR_xxx bit */
151 	unsigned int	cpu_user_ftrs;	/* PPC_FEATURE_xxx bit */
152 	unsigned char	pabyte;		/* byte number in ibm,pa-features */
153 	unsigned char	pabit;		/* bit number (big-endian) */
154 	unsigned char	invert;		/* if 1, pa bit set => clear feature */
155 } ibm_pa_features[] __initdata = {
156 	{0, 0, PPC_FEATURE_HAS_MMU,	0, 0, 0},
157 	{0, 0, PPC_FEATURE_HAS_FPU,	0, 1, 0},
158 	{CPU_FTR_CTRL, 0, 0,		0, 3, 0},
159 	{CPU_FTR_NOEXECUTE, 0, 0,	0, 6, 0},
160 	{CPU_FTR_NODSISRALIGN, 0, 0,	1, 1, 1},
161 	{0, MMU_FTR_CI_LARGE_PAGE, 0,	1, 2, 0},
162 	{CPU_FTR_REAL_LE, PPC_FEATURE_TRUE_LE, 5, 0, 0},
163 	/*
164 	 * If the kernel doesn't support TM (ie. CONFIG_PPC_TRANSACTIONAL_MEM=n),
165 	 * we don't want to turn on CPU_FTR_TM here, so we use CPU_FTR_TM_COMP
166 	 * which is 0 if the kernel doesn't support TM.
167 	 */
168 	{CPU_FTR_TM_COMP, 0, 0,		22, 0, 0},
169 };
170 
171 static void __init scan_features(unsigned long node, const unsigned char *ftrs,
172 				 unsigned long tablelen,
173 				 struct ibm_pa_feature *fp,
174 				 unsigned long ft_size)
175 {
176 	unsigned long i, len, bit;
177 
178 	/* find descriptor with type == 0 */
179 	for (;;) {
180 		if (tablelen < 3)
181 			return;
182 		len = 2 + ftrs[0];
183 		if (tablelen < len)
184 			return;		/* descriptor 0 not found */
185 		if (ftrs[1] == 0)
186 			break;
187 		tablelen -= len;
188 		ftrs += len;
189 	}
190 
191 	/* loop over bits we know about */
192 	for (i = 0; i < ft_size; ++i, ++fp) {
193 		if (fp->pabyte >= ftrs[0])
194 			continue;
195 		bit = (ftrs[2 + fp->pabyte] >> (7 - fp->pabit)) & 1;
196 		if (bit ^ fp->invert) {
197 			cur_cpu_spec->cpu_features |= fp->cpu_features;
198 			cur_cpu_spec->cpu_user_features |= fp->cpu_user_ftrs;
199 			cur_cpu_spec->mmu_features |= fp->mmu_features;
200 		} else {
201 			cur_cpu_spec->cpu_features &= ~fp->cpu_features;
202 			cur_cpu_spec->cpu_user_features &= ~fp->cpu_user_ftrs;
203 			cur_cpu_spec->mmu_features &= ~fp->mmu_features;
204 		}
205 	}
206 }
207 
208 static void __init check_cpu_pa_features(unsigned long node)
209 {
210 	const unsigned char *pa_ftrs;
211 	int tablelen;
212 
213 	pa_ftrs = of_get_flat_dt_prop(node, "ibm,pa-features", &tablelen);
214 	if (pa_ftrs == NULL)
215 		return;
216 
217 	scan_features(node, pa_ftrs, tablelen,
218 		      ibm_pa_features, ARRAY_SIZE(ibm_pa_features));
219 }
220 
221 #ifdef CONFIG_PPC_STD_MMU_64
222 static void __init check_cpu_slb_size(unsigned long node)
223 {
224 	const __be32 *slb_size_ptr;
225 
226 	slb_size_ptr = of_get_flat_dt_prop(node, "slb-size", NULL);
227 	if (slb_size_ptr != NULL) {
228 		mmu_slb_size = be32_to_cpup(slb_size_ptr);
229 		return;
230 	}
231 	slb_size_ptr = of_get_flat_dt_prop(node, "ibm,slb-size", NULL);
232 	if (slb_size_ptr != NULL) {
233 		mmu_slb_size = be32_to_cpup(slb_size_ptr);
234 	}
235 }
236 #else
237 #define check_cpu_slb_size(node) do { } while(0)
238 #endif
239 
240 static struct feature_property {
241 	const char *name;
242 	u32 min_value;
243 	unsigned long cpu_feature;
244 	unsigned long cpu_user_ftr;
245 } feature_properties[] __initdata = {
246 #ifdef CONFIG_ALTIVEC
247 	{"altivec", 0, CPU_FTR_ALTIVEC, PPC_FEATURE_HAS_ALTIVEC},
248 	{"ibm,vmx", 1, CPU_FTR_ALTIVEC, PPC_FEATURE_HAS_ALTIVEC},
249 #endif /* CONFIG_ALTIVEC */
250 #ifdef CONFIG_VSX
251 	/* Yes, this _really_ is ibm,vmx == 2 to enable VSX */
252 	{"ibm,vmx", 2, CPU_FTR_VSX, PPC_FEATURE_HAS_VSX},
253 #endif /* CONFIG_VSX */
254 #ifdef CONFIG_PPC64
255 	{"ibm,dfp", 1, 0, PPC_FEATURE_HAS_DFP},
256 	{"ibm,purr", 1, CPU_FTR_PURR, 0},
257 	{"ibm,spurr", 1, CPU_FTR_SPURR, 0},
258 #endif /* CONFIG_PPC64 */
259 };
260 
261 #if defined(CONFIG_44x) && defined(CONFIG_PPC_FPU)
262 static inline void identical_pvr_fixup(unsigned long node)
263 {
264 	unsigned int pvr;
265 	const char *model = of_get_flat_dt_prop(node, "model", NULL);
266 
267 	/*
268 	 * Since 440GR(x)/440EP(x) processors have the same pvr,
269 	 * we check the node path and set bit 28 in the cur_cpu_spec
270 	 * pvr for EP(x) processor version. This bit is always 0 in
271 	 * the "real" pvr. Then we call identify_cpu again with
272 	 * the new logical pvr to enable FPU support.
273 	 */
274 	if (model && strstr(model, "440EP")) {
275 		pvr = cur_cpu_spec->pvr_value | 0x8;
276 		identify_cpu(0, pvr);
277 		DBG("Using logical pvr %x for %s\n", pvr, model);
278 	}
279 }
280 #else
281 #define identical_pvr_fixup(node) do { } while(0)
282 #endif
283 
284 static void __init check_cpu_feature_properties(unsigned long node)
285 {
286 	unsigned long i;
287 	struct feature_property *fp = feature_properties;
288 	const __be32 *prop;
289 
290 	for (i = 0; i < ARRAY_SIZE(feature_properties); ++i, ++fp) {
291 		prop = of_get_flat_dt_prop(node, fp->name, NULL);
292 		if (prop && be32_to_cpup(prop) >= fp->min_value) {
293 			cur_cpu_spec->cpu_features |= fp->cpu_feature;
294 			cur_cpu_spec->cpu_user_features |= fp->cpu_user_ftr;
295 		}
296 	}
297 }
298 
299 static int __init early_init_dt_scan_cpus(unsigned long node,
300 					  const char *uname, int depth,
301 					  void *data)
302 {
303 	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
304 	const __be32 *prop;
305 	const __be32 *intserv;
306 	int i, nthreads;
307 	int len;
308 	int found = -1;
309 	int found_thread = 0;
310 
311 	/* We are scanning "cpu" nodes only */
312 	if (type == NULL || strcmp(type, "cpu") != 0)
313 		return 0;
314 
315 	/* Get physical cpuid */
316 	intserv = of_get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s", &len);
317 	if (!intserv)
318 		intserv = of_get_flat_dt_prop(node, "reg", &len);
319 
320 	nthreads = len / sizeof(int);
321 
322 	/*
323 	 * Now see if any of these threads match our boot cpu.
324 	 * NOTE: This must match the parsing done in smp_setup_cpu_maps.
325 	 */
326 	for (i = 0; i < nthreads; i++) {
327 		/*
328 		 * version 2 of the kexec param format adds the phys cpuid of
329 		 * booted proc.
330 		 */
331 		if (fdt_version(initial_boot_params) >= 2) {
332 			if (be32_to_cpu(intserv[i]) ==
333 			    fdt_boot_cpuid_phys(initial_boot_params)) {
334 				found = boot_cpu_count;
335 				found_thread = i;
336 			}
337 		} else {
338 			/*
339 			 * Check if it's the boot-cpu, set it's hw index now,
340 			 * unfortunately this format did not support booting
341 			 * off secondary threads.
342 			 */
343 			if (of_get_flat_dt_prop(node,
344 					"linux,boot-cpu", NULL) != NULL)
345 				found = boot_cpu_count;
346 		}
347 #ifdef CONFIG_SMP
348 		/* logical cpu id is always 0 on UP kernels */
349 		boot_cpu_count++;
350 #endif
351 	}
352 
353 	/* Not the boot CPU */
354 	if (found < 0)
355 		return 0;
356 
357 	DBG("boot cpu: logical %d physical %d\n", found,
358 	    be32_to_cpu(intserv[found_thread]));
359 	boot_cpuid = found;
360 	set_hard_smp_processor_id(found, be32_to_cpu(intserv[found_thread]));
361 
362 	/*
363 	 * PAPR defines "logical" PVR values for cpus that
364 	 * meet various levels of the architecture:
365 	 * 0x0f000001	Architecture version 2.04
366 	 * 0x0f000002	Architecture version 2.05
367 	 * If the cpu-version property in the cpu node contains
368 	 * such a value, we call identify_cpu again with the
369 	 * logical PVR value in order to use the cpu feature
370 	 * bits appropriate for the architecture level.
371 	 *
372 	 * A POWER6 partition in "POWER6 architected" mode
373 	 * uses the 0x0f000002 PVR value; in POWER5+ mode
374 	 * it uses 0x0f000001.
375 	 */
376 	prop = of_get_flat_dt_prop(node, "cpu-version", NULL);
377 	if (prop && (be32_to_cpup(prop) & 0xff000000) == 0x0f000000)
378 		identify_cpu(0, be32_to_cpup(prop));
379 
380 	identical_pvr_fixup(node);
381 
382 	check_cpu_feature_properties(node);
383 	check_cpu_pa_features(node);
384 	check_cpu_slb_size(node);
385 
386 #ifdef CONFIG_PPC64
387 	if (nthreads > 1)
388 		cur_cpu_spec->cpu_features |= CPU_FTR_SMT;
389 	else
390 		cur_cpu_spec->cpu_features &= ~CPU_FTR_SMT;
391 #endif
392 	return 0;
393 }
394 
395 static int __init early_init_dt_scan_chosen_ppc(unsigned long node,
396 						const char *uname,
397 						int depth, void *data)
398 {
399 	const unsigned long *lprop; /* All these set by kernel, so no need to convert endian */
400 
401 	/* Use common scan routine to determine if this is the chosen node */
402 	if (early_init_dt_scan_chosen(node, uname, depth, data) == 0)
403 		return 0;
404 
405 #ifdef CONFIG_PPC64
406 	/* check if iommu is forced on or off */
407 	if (of_get_flat_dt_prop(node, "linux,iommu-off", NULL) != NULL)
408 		iommu_is_off = 1;
409 	if (of_get_flat_dt_prop(node, "linux,iommu-force-on", NULL) != NULL)
410 		iommu_force_on = 1;
411 #endif
412 
413 	/* mem=x on the command line is the preferred mechanism */
414 	lprop = of_get_flat_dt_prop(node, "linux,memory-limit", NULL);
415 	if (lprop)
416 		memory_limit = *lprop;
417 
418 #ifdef CONFIG_PPC64
419 	lprop = of_get_flat_dt_prop(node, "linux,tce-alloc-start", NULL);
420 	if (lprop)
421 		tce_alloc_start = *lprop;
422 	lprop = of_get_flat_dt_prop(node, "linux,tce-alloc-end", NULL);
423 	if (lprop)
424 		tce_alloc_end = *lprop;
425 #endif
426 
427 #ifdef CONFIG_KEXEC
428 	lprop = of_get_flat_dt_prop(node, "linux,crashkernel-base", NULL);
429 	if (lprop)
430 		crashk_res.start = *lprop;
431 
432 	lprop = of_get_flat_dt_prop(node, "linux,crashkernel-size", NULL);
433 	if (lprop)
434 		crashk_res.end = crashk_res.start + *lprop - 1;
435 #endif
436 
437 	/* break now */
438 	return 1;
439 }
440 
441 #ifdef CONFIG_PPC_PSERIES
442 /*
443  * Interpret the ibm,dynamic-memory property in the
444  * /ibm,dynamic-reconfiguration-memory node.
445  * This contains a list of memory blocks along with NUMA affinity
446  * information.
447  */
448 static int __init early_init_dt_scan_drconf_memory(unsigned long node)
449 {
450 	const __be32 *dm, *ls, *usm;
451 	int l;
452 	unsigned long n, flags;
453 	u64 base, size, memblock_size;
454 	unsigned int is_kexec_kdump = 0, rngs;
455 
456 	ls = of_get_flat_dt_prop(node, "ibm,lmb-size", &l);
457 	if (ls == NULL || l < dt_root_size_cells * sizeof(__be32))
458 		return 0;
459 	memblock_size = dt_mem_next_cell(dt_root_size_cells, &ls);
460 
461 	dm = of_get_flat_dt_prop(node, "ibm,dynamic-memory", &l);
462 	if (dm == NULL || l < sizeof(__be32))
463 		return 0;
464 
465 	n = of_read_number(dm++, 1);	/* number of entries */
466 	if (l < (n * (dt_root_addr_cells + 4) + 1) * sizeof(__be32))
467 		return 0;
468 
469 	/* check if this is a kexec/kdump kernel. */
470 	usm = of_get_flat_dt_prop(node, "linux,drconf-usable-memory",
471 						 &l);
472 	if (usm != NULL)
473 		is_kexec_kdump = 1;
474 
475 	for (; n != 0; --n) {
476 		base = dt_mem_next_cell(dt_root_addr_cells, &dm);
477 		flags = of_read_number(&dm[3], 1);
478 		/* skip DRC index, pad, assoc. list index, flags */
479 		dm += 4;
480 		/* skip this block if the reserved bit is set in flags (0x80)
481 		   or if the block is not assigned to this partition (0x8) */
482 		if ((flags & 0x80) || !(flags & 0x8))
483 			continue;
484 		size = memblock_size;
485 		rngs = 1;
486 		if (is_kexec_kdump) {
487 			/*
488 			 * For each memblock in ibm,dynamic-memory, a corresponding
489 			 * entry in linux,drconf-usable-memory property contains
490 			 * a counter 'p' followed by 'p' (base, size) duple.
491 			 * Now read the counter from
492 			 * linux,drconf-usable-memory property
493 			 */
494 			rngs = dt_mem_next_cell(dt_root_size_cells, &usm);
495 			if (!rngs) /* there are no (base, size) duple */
496 				continue;
497 		}
498 		do {
499 			if (is_kexec_kdump) {
500 				base = dt_mem_next_cell(dt_root_addr_cells,
501 							 &usm);
502 				size = dt_mem_next_cell(dt_root_size_cells,
503 							 &usm);
504 			}
505 			if (iommu_is_off) {
506 				if (base >= 0x80000000ul)
507 					continue;
508 				if ((base + size) > 0x80000000ul)
509 					size = 0x80000000ul - base;
510 			}
511 			memblock_add(base, size);
512 		} while (--rngs);
513 	}
514 	memblock_dump_all();
515 	return 0;
516 }
517 #else
518 #define early_init_dt_scan_drconf_memory(node)	0
519 #endif /* CONFIG_PPC_PSERIES */
520 
521 static int __init early_init_dt_scan_memory_ppc(unsigned long node,
522 						const char *uname,
523 						int depth, void *data)
524 {
525 	if (depth == 1 &&
526 	    strcmp(uname, "ibm,dynamic-reconfiguration-memory") == 0)
527 		return early_init_dt_scan_drconf_memory(node);
528 
529 	return early_init_dt_scan_memory(node, uname, depth, data);
530 }
531 
532 /*
533  * For a relocatable kernel, we need to get the memstart_addr first,
534  * then use it to calculate the virtual kernel start address. This has
535  * to happen at a very early stage (before machine_init). In this case,
536  * we just want to get the memstart_address and would not like to mess the
537  * memblock at this stage. So introduce a variable to skip the memblock_add()
538  * for this reason.
539  */
540 #ifdef CONFIG_RELOCATABLE
541 static int add_mem_to_memblock = 1;
542 #else
543 #define add_mem_to_memblock 1
544 #endif
545 
546 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
547 {
548 #ifdef CONFIG_PPC64
549 	if (iommu_is_off) {
550 		if (base >= 0x80000000ul)
551 			return;
552 		if ((base + size) > 0x80000000ul)
553 			size = 0x80000000ul - base;
554 	}
555 #endif
556 	/* Keep track of the beginning of memory -and- the size of
557 	 * the very first block in the device-tree as it represents
558 	 * the RMA on ppc64 server
559 	 */
560 	if (base < memstart_addr) {
561 		memstart_addr = base;
562 		first_memblock_size = size;
563 	}
564 
565 	/* Add the chunk to the MEMBLOCK list */
566 	if (add_mem_to_memblock)
567 		memblock_add(base, size);
568 }
569 
570 static void __init early_reserve_mem_dt(void)
571 {
572 	unsigned long i, dt_root;
573 	int len;
574 	const __be32 *prop;
575 
576 	early_init_fdt_scan_reserved_mem();
577 
578 	dt_root = of_get_flat_dt_root();
579 
580 	prop = of_get_flat_dt_prop(dt_root, "reserved-ranges", &len);
581 
582 	if (!prop)
583 		return;
584 
585 	DBG("Found new-style reserved-ranges\n");
586 
587 	/* Each reserved range is an (address,size) pair, 2 cells each,
588 	 * totalling 4 cells per range. */
589 	for (i = 0; i < len / (sizeof(*prop) * 4); i++) {
590 		u64 base, size;
591 
592 		base = of_read_number(prop + (i * 4) + 0, 2);
593 		size = of_read_number(prop + (i * 4) + 2, 2);
594 
595 		if (size) {
596 			DBG("reserving: %llx -> %llx\n", base, size);
597 			memblock_reserve(base, size);
598 		}
599 	}
600 }
601 
602 static void __init early_reserve_mem(void)
603 {
604 	__be64 *reserve_map;
605 
606 	reserve_map = (__be64 *)(((unsigned long)initial_boot_params) +
607 			fdt_off_mem_rsvmap(initial_boot_params));
608 
609 	/* Look for the new "reserved-regions" property in the DT */
610 	early_reserve_mem_dt();
611 
612 #ifdef CONFIG_BLK_DEV_INITRD
613 	/* Then reserve the initrd, if any */
614 	if (initrd_start && (initrd_end > initrd_start)) {
615 		memblock_reserve(_ALIGN_DOWN(__pa(initrd_start), PAGE_SIZE),
616 			_ALIGN_UP(initrd_end, PAGE_SIZE) -
617 			_ALIGN_DOWN(initrd_start, PAGE_SIZE));
618 	}
619 #endif /* CONFIG_BLK_DEV_INITRD */
620 
621 #ifdef CONFIG_PPC32
622 	/*
623 	 * Handle the case where we might be booting from an old kexec
624 	 * image that setup the mem_rsvmap as pairs of 32-bit values
625 	 */
626 	if (be64_to_cpup(reserve_map) > 0xffffffffull) {
627 		u32 base_32, size_32;
628 		__be32 *reserve_map_32 = (__be32 *)reserve_map;
629 
630 		DBG("Found old 32-bit reserve map\n");
631 
632 		while (1) {
633 			base_32 = be32_to_cpup(reserve_map_32++);
634 			size_32 = be32_to_cpup(reserve_map_32++);
635 			if (size_32 == 0)
636 				break;
637 			DBG("reserving: %x -> %x\n", base_32, size_32);
638 			memblock_reserve(base_32, size_32);
639 		}
640 		return;
641 	}
642 #endif
643 }
644 
645 void __init early_init_devtree(void *params)
646 {
647 	phys_addr_t limit;
648 
649 	DBG(" -> early_init_devtree(%p)\n", params);
650 
651 	/* Too early to BUG_ON(), do it by hand */
652 	if (!early_init_dt_verify(params))
653 		panic("BUG: Failed verifying flat device tree, bad version?");
654 
655 	/* Setup flat device-tree pointer */
656 	initial_boot_params = params;
657 
658 #ifdef CONFIG_PPC_RTAS
659 	/* Some machines might need RTAS info for debugging, grab it now. */
660 	of_scan_flat_dt(early_init_dt_scan_rtas, NULL);
661 #endif
662 
663 #ifdef CONFIG_PPC_POWERNV
664 	/* Some machines might need OPAL info for debugging, grab it now. */
665 	of_scan_flat_dt(early_init_dt_scan_opal, NULL);
666 #endif
667 
668 #ifdef CONFIG_FA_DUMP
669 	/* scan tree to see if dump is active during last boot */
670 	of_scan_flat_dt(early_init_dt_scan_fw_dump, NULL);
671 #endif
672 
673 	/* Retrieve various informations from the /chosen node of the
674 	 * device-tree, including the platform type, initrd location and
675 	 * size, TCE reserve, and more ...
676 	 */
677 	of_scan_flat_dt(early_init_dt_scan_chosen_ppc, boot_command_line);
678 
679 	/* Scan memory nodes and rebuild MEMBLOCKs */
680 	of_scan_flat_dt(early_init_dt_scan_root, NULL);
681 	of_scan_flat_dt(early_init_dt_scan_memory_ppc, NULL);
682 
683 	parse_early_param();
684 
685 	/* make sure we've parsed cmdline for mem= before this */
686 	if (memory_limit)
687 		first_memblock_size = min_t(u64, first_memblock_size, memory_limit);
688 	setup_initial_memory_limit(memstart_addr, first_memblock_size);
689 	/* Reserve MEMBLOCK regions used by kernel, initrd, dt, etc... */
690 	memblock_reserve(PHYSICAL_START, __pa(klimit) - PHYSICAL_START);
691 	/* If relocatable, reserve first 32k for interrupt vectors etc. */
692 	if (PHYSICAL_START > MEMORY_START)
693 		memblock_reserve(MEMORY_START, 0x8000);
694 	reserve_kdump_trampoline();
695 #ifdef CONFIG_FA_DUMP
696 	/*
697 	 * If we fail to reserve memory for firmware-assisted dump then
698 	 * fallback to kexec based kdump.
699 	 */
700 	if (fadump_reserve_mem() == 0)
701 #endif
702 		reserve_crashkernel();
703 	early_reserve_mem();
704 
705 	/* Ensure that total memory size is page-aligned. */
706 	limit = ALIGN(memory_limit ?: memblock_phys_mem_size(), PAGE_SIZE);
707 	memblock_enforce_memory_limit(limit);
708 
709 	memblock_allow_resize();
710 	memblock_dump_all();
711 
712 	DBG("Phys. mem: %llx\n", memblock_phys_mem_size());
713 
714 	/* We may need to relocate the flat tree, do it now.
715 	 * FIXME .. and the initrd too? */
716 	move_device_tree();
717 
718 	allocate_pacas();
719 
720 	DBG("Scanning CPUs ...\n");
721 
722 	/* Retrieve CPU related informations from the flat tree
723 	 * (altivec support, boot CPU ID, ...)
724 	 */
725 	of_scan_flat_dt(early_init_dt_scan_cpus, NULL);
726 	if (boot_cpuid < 0) {
727 		printk("Failed to indentify boot CPU !\n");
728 		BUG();
729 	}
730 
731 #if defined(CONFIG_SMP) && defined(CONFIG_PPC64)
732 	/* We'll later wait for secondaries to check in; there are
733 	 * NCPUS-1 non-boot CPUs  :-)
734 	 */
735 	spinning_secondaries = boot_cpu_count - 1;
736 #endif
737 
738 #ifdef CONFIG_PPC_POWERNV
739 	/* Scan and build the list of machine check recoverable ranges */
740 	of_scan_flat_dt(early_init_dt_scan_recoverable_ranges, NULL);
741 #endif
742 
743 	DBG(" <- early_init_devtree()\n");
744 }
745 
746 #ifdef CONFIG_RELOCATABLE
747 /*
748  * This function run before early_init_devtree, so we have to init
749  * initial_boot_params.
750  */
751 void __init early_get_first_memblock_info(void *params, phys_addr_t *size)
752 {
753 	/* Setup flat device-tree pointer */
754 	initial_boot_params = params;
755 
756 	/*
757 	 * Scan the memory nodes and set add_mem_to_memblock to 0 to avoid
758 	 * mess the memblock.
759 	 */
760 	add_mem_to_memblock = 0;
761 	of_scan_flat_dt(early_init_dt_scan_root, NULL);
762 	of_scan_flat_dt(early_init_dt_scan_memory_ppc, NULL);
763 	add_mem_to_memblock = 1;
764 
765 	if (size)
766 		*size = first_memblock_size;
767 }
768 #endif
769 
770 /*******
771  *
772  * New implementation of the OF "find" APIs, return a refcounted
773  * object, call of_node_put() when done.  The device tree and list
774  * are protected by a rw_lock.
775  *
776  * Note that property management will need some locking as well,
777  * this isn't dealt with yet.
778  *
779  *******/
780 
781 /**
782  * of_get_ibm_chip_id - Returns the IBM "chip-id" of a device
783  * @np: device node of the device
784  *
785  * This looks for a property "ibm,chip-id" in the node or any
786  * of its parents and returns its content, or -1 if it cannot
787  * be found.
788  */
789 int of_get_ibm_chip_id(struct device_node *np)
790 {
791 	of_node_get(np);
792 	while(np) {
793 		struct device_node *old = np;
794 		const __be32 *prop;
795 
796 		prop = of_get_property(np, "ibm,chip-id", NULL);
797 		if (prop) {
798 			of_node_put(np);
799 			return be32_to_cpup(prop);
800 		}
801 		np = of_get_parent(np);
802 		of_node_put(old);
803 	}
804 	return -1;
805 }
806 
807 /**
808  * cpu_to_chip_id - Return the cpus chip-id
809  * @cpu: The logical cpu number.
810  *
811  * Return the value of the ibm,chip-id property corresponding to the given
812  * logical cpu number. If the chip-id can not be found, returns -1.
813  */
814 int cpu_to_chip_id(int cpu)
815 {
816 	struct device_node *np;
817 
818 	np = of_get_cpu_node(cpu, NULL);
819 	if (!np)
820 		return -1;
821 
822 	of_node_put(np);
823 	return of_get_ibm_chip_id(np);
824 }
825 EXPORT_SYMBOL(cpu_to_chip_id);
826 
827 bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
828 {
829 	return (int)phys_id == get_hard_smp_processor_id(cpu);
830 }
831