summaryrefslogtreecommitdiffstats
path: root/arch/mips/kernel/setup.c
blob: febdc5564638e9b9bbb959791ecb75d6068b676c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1995 Linus Torvalds
 * Copyright (C) 1995 Waldorf Electronics
 * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 01, 02, 03  Ralf Baechle
 * Copyright (C) 1996 Stoned Elipot
 * Copyright (C) 1999 Silicon Graphics, Inc.
 * Copyright (C) 2000, 2001, 2002, 2007	 Maciej W. Rozycki
 */
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/export.h>
#include <linux/screen_info.h>
#include <linux/memblock.h>
#include <linux/initrd.h>
#include <linux/root_dev.h>
#include <linux/highmem.h>
#include <linux/console.h>
#include <linux/pfn.h>
#include <linux/debugfs.h>
#include <linux/kexec.h>
#include <linux/sizes.h>
#include <linux/device.h>
#include <linux/dma-map-ops.h>
#include <linux/decompress/generic.h>
#include <linux/of_fdt.h>
#include <linux/dmi.h>
#include <linux/crash_dump.h>

#include <asm/addrspace.h>
#include <asm/bootinfo.h>
#include <asm/bugs.h>
#include <asm/cache.h>
#include <asm/cdmm.h>
#include <asm/cpu.h>
#include <asm/debug.h>
#include <asm/mmzone.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/smp-ops.h>
#include <asm/prom.h>
#include <asm/fw/fw.h>

#ifdef CONFIG_MIPS_ELF_APPENDED_DTB
char __section(".appended_dtb") __appended_dtb[0x100000];
#endif /* CONFIG_MIPS_ELF_APPENDED_DTB */

struct cpuinfo_mips cpu_data[NR_CPUS] __read_mostly;

EXPORT_SYMBOL(cpu_data);

#ifdef CONFIG_VT
struct screen_info screen_info;
#endif

/*
 * Setup information
 *
 * These are initialized so they are in the .data section
 */
unsigned long mips_machtype __read_mostly = MACH_UNKNOWN;

EXPORT_SYMBOL(mips_machtype);

static char __initdata command_line[COMMAND_LINE_SIZE];
char __initdata arcs_cmdline[COMMAND_LINE_SIZE];

#ifdef CONFIG_CMDLINE_BOOL
static const char builtin_cmdline[] __initconst = CONFIG_CMDLINE;
#else
static const char builtin_cmdline[] __initconst = "";
#endif

/*
 * mips_io_port_base is the begin of the address space to which x86 style
 * I/O ports are mapped.
 */
unsigned long mips_io_port_base = -1;
EXPORT_SYMBOL(mips_io_port_base);

static struct resource code_resource = { .name = "Kernel code", };
static struct resource data_resource = { .name = "Kernel data", };
static struct resource bss_resource = { .name = "Kernel bss", };

unsigned long __kaslr_offset __ro_after_init;
EXPORT_SYMBOL(__kaslr_offset);

static void *detect_magic __initdata = detect_memory_region;

#ifdef CONFIG_MIPS_AUTO_PFN_OFFSET
unsigned long ARCH_PFN_OFFSET;
EXPORT_SYMBOL(ARCH_PFN_OFFSET);
#endif

void __init detect_memory_region(phys_addr_t start, phys_addr_t sz_min, phys_addr_t sz_max)
{
	void *dm = &detect_magic;
	phys_addr_t size;

	for (size = sz_min; size < sz_max; size <<= 1) {
		if (!memcmp(dm, dm + size, sizeof(detect_magic)))
			break;
	}

	pr_debug("Memory: %lluMB of RAM detected at 0x%llx (min: %lluMB, max: %lluMB)\n",
		((unsigned long long) size) / SZ_1M,
		(unsigned long long) start,
		((unsigned long long) sz_min) / SZ_1M,
		((unsigned long long) sz_max) / SZ_1M);

	memblock_add(start, size);
}

/*
 * Manage initrd
 */
#ifdef CONFIG_BLK_DEV_INITRD

static int __init rd_start_early(char *p)
{
	unsigned long start = memparse(p, &p);

#ifdef CONFIG_64BIT
	/* Guess if the sign extension was forgotten by bootloader */
	if (start < XKPHYS)
		start = (int)start;
#endif
	initrd_start = start;
	initrd_end += start;
	return 0;
}
early_param("rd_start", rd_start_early);

static int __init rd_size_early(char *p)
{
	initrd_end += memparse(p, &p);
	return 0;
}
early_param("rd_size", rd_size_early);

/* it returns the next free pfn after initrd */
static unsigned long __init init_initrd(void)
{
	unsigned long end;

	/*
	 * Board specific code or command line parser should have
	 * already set up initrd_start and initrd_end. In these cases
	 * perfom sanity checks and use them if all looks good.
	 */
	if (!initrd_start || initrd_end <= initrd_start)
		goto disable;

	if (initrd_start & ~PAGE_MASK) {
		pr_err("initrd start must be page aligned\n");
		goto disable;
	}
	if (initrd_start < PAGE_OFFSET) {
		pr_err("initrd start < PAGE_OFFSET\n");
		goto disable;
	}

	/*
	 * Sanitize initrd addresses. For example firmware
	 * can't guess if they need to pass them through
	 * 64-bits values if the kernel has been built in pure
	 * 32-bit. We need also to switch from KSEG0 to XKPHYS
	 * addresses now, so the code can now safely use __pa().
	 */
	end = __pa(initrd_end);
	initrd_end = (unsigned long)__va(end);
	initrd_start = (unsigned long)__va(__pa(initrd_start));

	ROOT_DEV = Root_RAM0;
	return PFN_UP(end);
disable:
	initrd_start = 0;
	initrd_end = 0;
	return 0;
}

/* In some conditions (e.g. big endian bootloader with a little endian
   kernel), the initrd might appear byte swapped.  Try to detect this and
   byte swap it if needed.  */
static void __init maybe_bswap_initrd(void)
{
#if defined(CONFIG_CPU_CAVIUM_OCTEON)
	u64 buf;

	/* Check for CPIO signature */
	if (!memcmp((void *)initrd_start, "070701", 6))
		return;

	/* Check for compressed initrd */
	if (decompress_method((unsigned char *)initrd_start, 8, NULL))
		return;

	/* Try again with a byte swapped header */
	buf = swab64p((u64 *)initrd_start);
	if (!memcmp(&buf, "070701", 6) ||
	    decompress_method((unsigned char *)(&buf), 8, NULL)) {
		unsigned long i;

		pr_info("Byteswapped initrd detected\n");
		for (i = initrd_start; i < ALIGN(initrd_end, 8); i += 8)
			swab64s((u64 *)i);
	}
#endif
}

static void __init finalize_initrd(void)
{
	unsigned long size = initrd_end - initrd_start;

	if (size == 0) {
		printk(KERN_INFO "Initrd not found or empty");
		goto disable;
	}
	if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
		printk(KERN_ERR "Initrd extends beyond end of memory");
		goto disable;
	}

	maybe_bswap_initrd();

	memblock_reserve(__pa(initrd_start), size);
	initrd_below_start_ok = 1;

	pr_info("Initial ramdisk at: 0x%lx (%lu bytes)\n",
		initrd_start, size);
	return;
disable:
	printk(KERN_CONT " - disabling initrd\n");
	initrd_start = 0;
	initrd_end = 0;
}

#else  /* !CONFIG_BLK_DEV_INITRD */

static unsigned long __init init_initrd(void)
{
	return 0;
}

#define finalize_initrd()	do {} while (0)

#endif

/*
 * Initialize the bootmem allocator. It also setup initrd related data
 * if needed.
 */
#if defined(CONFIG_SGI_IP27) || (defined(CONFIG_CPU_LOONGSON64) && defined(CONFIG_NUMA))

static void __init bootmem_init(void)
{
	init_initrd();
	finalize_initrd();
}

#else  /* !CONFIG_SGI_IP27 */

static void __init bootmem_init(void)
{
	phys_addr_t ramstart, ramend;
	unsigned long start, end;
	int i;

	ramstart = memblock_start_of_DRAM();
	ramend = memblock_end_of_DRAM();

	/*
	 * Sanity check any INITRD first. We don't take it into account
	 * for bootmem setup initially, rely on the end-of-kernel-code
	 * as our memory range starting point. Once bootmem is inited we
	 * will reserve the area used for the initrd.
	 */
	init_initrd();

	/* Reserve memory occupied by kernel. */
	memblock_reserve(__pa_symbol(&_text),
			__pa_symbol(&_end) - __pa_symbol(&_text));

	/* max_low_pfn is not a number of pages but the end pfn of low mem */

#ifdef CONFIG_MIPS_AUTO_PFN_OFFSET
	ARCH_PFN_OFFSET = PFN_UP(ramstart);
#else
	/*
	 * Reserve any memory between the start of RAM and PHYS_OFFSET
	 */
	if (ramstart > PHYS_OFFSET)
		memblock_reserve(PHYS_OFFSET, ramstart - PHYS_OFFSET);

	if (PFN_UP(ramstart) > ARCH_PFN_OFFSET) {
		pr_info("Wasting %lu bytes for tracking %lu unused pages\n",
			(unsigned long)((PFN_UP(ramstart) - ARCH_PFN_OFFSET) * sizeof(struct page)),
			(unsigned long)(PFN_UP(ramstart) - ARCH_PFN_OFFSET));
	}
#endif

	min_low_pfn = ARCH_PFN_OFFSET;
	max_pfn = PFN_DOWN(ramend);
	for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, NULL) {
		/*
		 * Skip highmem here so we get an accurate max_low_pfn if low
		 * memory stops short of high memory.
		 * If the region overlaps HIGHMEM_START, end is clipped so
		 * max_pfn excludes the highmem portion.
		 */
		if (start >= PFN_DOWN(HIGHMEM_START))
			continue;
		if (end > PFN_DOWN(HIGHMEM_START))
			end = PFN_DOWN(HIGHMEM_START);
		if (end > max_low_pfn)
			max_low_pfn = end;
	}

	if (min_low_pfn >= max_low_pfn)
		panic("Incorrect memory mapping !!!");

	if (max_pfn > PFN_DOWN(HIGHMEM_START)) {
#ifdef CONFIG_HIGHMEM
		highstart_pfn = PFN_DOWN(HIGHMEM_START);
		highend_pfn = max_pfn;
#else
		max_low_pfn = PFN_DOWN(HIGHMEM_START);
		max_pfn = max_low_pfn;
#endif
	}

	/*
	 * Reserve initrd memory if needed.
	 */
	finalize_initrd();
}

#endif	/* CONFIG_SGI_IP27 */

static int usermem __initdata;

static int __init early_parse_mem(char *p)
{
	phys_addr_t start, size;

	if (!p) {
		pr_err("mem parameter is empty, do nothing\n");
		return -EINVAL;
	}

	/*
	 * If a user specifies memory size, we
	 * blow away any automatically generated
	 * size.
	 */
	if (usermem == 0) {
		usermem = 1;
		memblock_remove(memblock_start_of_DRAM(),
			memblock_end_of_DRAM() - memblock_start_of_DRAM());
	}
	start = 0;
	size = memparse(p, &p);
	if (*p == '@')
		start = memparse(p + 1, &p);

	if (IS_ENABLED(CONFIG_NUMA))
		memblock_add_node(start, size, pa_to_nid(start), MEMBLOCK_NONE);
	else
		memblock_add(start, size);

	return 0;
}
early_param("mem", early_parse_mem);

static int __init early_parse_memmap(char *p)
{
	char *oldp;
	u64 start_at, mem_size;

	if (!p)
		return -EINVAL;

	if (!strncmp(p, "exactmap", 8)) {
		pr_err("\"memmap=exactmap\" invalid on MIPS\n");
		return 0;
	}

	oldp = p;
	mem_size = memparse(p, &p);
	if (p == oldp)
		return -EINVAL;

	if (*p == '@') {
		start_at = memparse(p+1, &p);
		memblock_add(start_at, mem_size);
	} else if (*p == '#') {
		pr_err("\"memmap=nn#ss\" (force ACPI data) invalid on MIPS\n");
		return -EINVAL;
	} else if (*p == '$') {
		start_at = memparse(p+1, &p);
		memblock_add(start_at, mem_size);
		memblock_reserve(start_at, mem_size);
	} else {
		pr_err("\"memmap\" invalid format!\n");
		return -EINVAL;
	}

	if (*p == '\0') {
		usermem = 1;
		return 0;
	} else
		return -EINVAL;
}
early_param("memmap", early_parse_memmap);

static void __init mips_reserve_vmcore(void)
{
#ifdef CONFIG_PROC_VMCORE
	phys_addr_t start, end;
	u64 i;

	if (!elfcorehdr_size) {
		for_each_mem_range(i, &start, &end) {
			if (elfcorehdr_addr >= start && elfcorehdr_addr < end) {
				/*
				 * Reserve from the elf core header to the end of
				 * the memory segment, that should all be kdump
				 * reserved memory.
				 */
				elfcorehdr_size = end - elfcorehdr_addr;
				break;
			}
		}
	}

	pr_info("Reserving %ldKB of memory at %ldKB for kdump\n",
		(unsigned long)elfcorehdr_size >> 10, (unsigned long)elfcorehdr_addr >> 10);

	memblock_reserve(elfcorehdr_addr, elfcorehdr_size);
#endif
}

#ifdef CONFIG_KEXEC

/* 64M alignment for crash kernel regions */
#define CRASH_ALIGN	SZ_64M
#define CRASH_ADDR_MAX	SZ_512M

static void __init mips_parse_crashkernel(void)
{
	unsigned long long total_mem;
	unsigned long long crash_size, crash_base;
	int ret;

	total_mem = memblock_phys_mem_size();
	ret = parse_crashkernel(boot_command_line, total_mem,
				&crash_size, &crash_base);
	if (ret != 0 || crash_size <= 0)
		return;

	if (crash_base <= 0) {
		crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN,
						       CRASH_ALIGN,
						       CRASH_ADDR_MAX);
		if (!crash_base) {
			pr_warn("crashkernel reservation failed - No suitable area found.\n");
			return;
		}
	} else {
		unsigned long long start;

		start = memblock_phys_alloc_range(crash_size, 1,
						  crash_base,
						  crash_base + crash_size);
		if (start != crash_base) {
			pr_warn("Invalid memory region reserved for crash kernel\n");
			return;
		}
	}

	crashk_res.start = crash_base;
	crashk_res.end	 = crash_base + crash_size - 1;
}

static void __init request_crashkernel(struct resource *res)
{
	int ret;

	if (crashk_res.start == crashk_res.end)
		return;

	ret = request_resource(res, &crashk_res);
	if (!ret)
		pr_info("Reserving %ldMB of memory at %ldMB for crashkernel\n",
			(unsigned long)(resource_size(&crashk_res) >> 20),
			(unsigned long)(crashk_res.start  >> 20));
}
#else /* !defined(CONFIG_KEXEC)		*/
static void __init mips_parse_crashkernel(void)
{
}

static void __init request_crashkernel(struct resource *res)
{
}
#endif /* !defined(CONFIG_KEXEC)  */

static void __init check_kernel_sections_mem(void)
{
	phys_addr_t start = __pa_symbol(&_text);
	phys_addr_t size = __pa_symbol(&_end) - start;

	if (!memblock_is_region_memory(start, size)) {
		pr_info("Kernel sections are not in the memory maps\n");
		memblock_add(start, size);
	}
}

static void __init bootcmdline_append(const char *s, size_t max)
{
	if (!s[0] || !max)
		return;

	if (boot_command_line[0])
		strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);

	strlcat(boot_command_line, s, max);
}

#ifdef CONFIG_OF_EARLY_FLATTREE

static int __init bootcmdline_scan_chosen(unsigned long node, const char *uname,
					  int depth, void *data)
{
	bool *dt_bootargs = data;
	const char *p;
	int l;

	if (depth != 1 || !data ||
	    (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
		return 0;

	p = of_get_flat_dt_prop(node, "bootargs", &l);
	if (p != NULL && l > 0) {
		bootcmdline_append(p, min(l, COMMAND_LINE_SIZE));
		*dt_bootargs = true;
	}

	return 1;
}

#endif /* CONFIG_OF_EARLY_FLATTREE */

static void __init bootcmdline_init(void)
{
	bool dt_bootargs = false;

	/*
	 * If CMDLINE_OVERRIDE is enabled then initializing the command line is
	 * trivial - we simply use the built-in command line unconditionally &
	 * unmodified.
	 */
	if (IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
		strscpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
		return;
	}

	/*
	 * If the user specified a built-in command line &
	 * MIPS_CMDLINE_BUILTIN_EXTEND, then the built-in command line is
	 * prepended to arguments from the bootloader or DT so we'll copy them
	 * to the start of boot_command_line here. Otherwise, empty
	 * boot_command_line to undo anything early_init_dt_scan_chosen() did.
	 */
	if (IS_ENABLED(CONFIG_MIPS_CMDLINE_BUILTIN_EXTEND))
		strscpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
	else
		boot_command_line[0] = 0;

#ifdef CONFIG_OF_EARLY_FLATTREE
	/*
	 * If we're configured to take boot arguments from DT, look for those
	 * now.
	 */
	if (IS_ENABLED(CONFIG_MIPS_CMDLINE_FROM_DTB) ||
	    IS_ENABLED(CONFIG_MIPS_CMDLINE_DTB_EXTEND))
		of_scan_flat_dt(bootcmdline_scan_chosen, &dt_bootargs);
#endif

	/*
	 * If we didn't get any arguments from DT (regardless of whether that's
	 * because we weren't configured to look for them, or because we looked
	 * & found none) then we'll take arguments from the bootloader.
	 * plat_mem_setup() should have filled arcs_cmdline with arguments from
	 * the bootloader.
	 */
	if (IS_ENABLED(CONFIG_MIPS_CMDLINE_DTB_EXTEND) || !dt_bootargs)
		bootcmdline_append(arcs_cmdline, COMMAND_LINE_SIZE);

	/*
	 * If the user specified a built-in command line & we didn't already
	 * prepend it, we append it to boot_command_line here.
	 */
	if (IS_ENABLED(CONFIG_CMDLINE_BOOL) &&
	    !IS_ENABLED(CONFIG_MIPS_CMDLINE_BUILTIN_EXTEND))
		bootcmdline_append(builtin_cmdline, COMMAND_LINE_SIZE);
}

/*
 * arch_mem_init - initialize memory management subsystem
 *
 *  o plat_mem_setup() detects the memory configuration and will record detected
 *    memory areas using memblock_add.
 *
 * At this stage the memory configuration of the system is known to the
 * kernel but generic memory management system is still entirely uninitialized.
 *
 *  o bootmem_init()
 *  o sparse_init()
 *  o paging_init()
 *  o dma_contiguous_reserve()
 *
 * At this stage the bootmem allocator is ready to use.
 *
 * NOTE: historically plat_mem_setup did the entire platform initialization.
 *	 This was rather impractical because it meant plat_mem_setup had to
 * get away without any kind of memory allocator.  To keep old code from
 * breaking plat_setup was just renamed to plat_mem_setup and a second platform
 * initialization hook for anything else was introduced.
 */
static void __init arch_mem_init(char **cmdline_p)
{
	/* call board setup routine */
	plat_mem_setup();
	memblock_set_bottom_up(true);

	bootcmdline_init();
	strscpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
	*cmdline_p = command_line;

	parse_early_param();

	if (usermem)
		pr_info("User-defined physical RAM map overwrite\n");

	check_kernel_sections_mem();

	early_init_fdt_reserve_self();
	early_init_fdt_scan_reserved_mem();

#ifndef CONFIG_NUMA
	memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
#endif
	bootmem_init();

	/*
	 * Prevent memblock from allocating high memory.
	 * This cannot be done before max_low_pfn is detected, so up
	 * to this point is possible to only reserve physical memory
	 * with memblock_reserve; memblock_alloc* can be used
	 * only after this point
	 */
	memblock_set_current_limit(PFN_PHYS(max_low_pfn));

	mips_reserve_vmcore();

	mips_parse_crashkernel();
	device_tree_init();

	/*
	 * In order to reduce the possibility of kernel panic when failed to
	 * get IO TLB memory under CONFIG_SWIOTLB, it is better to allocate
	 * low memory as small as possible before plat_swiotlb_setup(), so
	 * make sparse_init() using top-down allocation.
	 */
	memblock_set_bottom_up(false);
	sparse_init();
	memblock_set_bottom_up(true);

	plat_swiotlb_setup();

	dma_contiguous_reserve(PFN_PHYS(max_low_pfn));

	/* Reserve for hibernation. */
	memblock_reserve(__pa_symbol(&__nosave_begin),
		__pa_symbol(&__nosave_end) - __pa_symbol(&__nosave_begin));

	early_memtest(PFN_PHYS(ARCH_PFN_OFFSET), PFN_PHYS(max_low_pfn));
}

static void __init resource_init(void)
{
	phys_addr_t start, end;
	u64 i;

	if (UNCAC_BASE != IO_BASE)
		return;

	code_resource.start = __pa_symbol(&_text);
	code_resource.end = __pa_symbol(&_etext) - 1;
	data_resource.start = __pa_symbol(&_etext);
	data_resource.end = __pa_symbol(&_edata) - 1;
	bss_resource.start = __pa_symbol(&__bss_start);
	bss_resource.end = __pa_symbol(&__bss_stop) - 1;

	for_each_mem_range(i, &start, &end) {
		struct resource *res;

		res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);
		if (!res)
			panic("%s: Failed to allocate %zu bytes\n", __func__,
			      sizeof(struct resource));

		res->start = start;
		/*
		 * In memblock, end points to the first byte after the
		 * range while in resourses, end points to the last byte in
		 * the range.
		 */
		res->end = end - 1;
		res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
		res->name = "System RAM";

		request_resource(&iomem_resource, res);

		/*
		 *  We don't know which RAM region contains kernel data,
		 *  so we try it repeatedly and let the resource manager
		 *  test it.
		 */
		request_resource(res, &code_resource);
		request_resource(res, &data_resource);
		request_resource(res, &bss_resource);
		request_crashkernel(res);
	}
}

#ifdef CONFIG_SMP
static void __init prefill_possible_map(void)
{
	int i, possible = num_possible_cpus();

	if (possible > nr_cpu_ids)
		possible = nr_cpu_ids;

	for (i = 0; i < possible; i++)
		set_cpu_possible(i, true);
	for (; i < NR_CPUS; i++)
		set_cpu_possible(i, false);

	set_nr_cpu_ids(possible);
}
#else
static inline void prefill_possible_map(void) {}
#endif

static void __init setup_rng_seed(void)
{
	char *rng_seed_hex = fw_getenv("rngseed");
	u8 rng_seed[512];
	size_t len;

	if (!rng_seed_hex)
		return;

	len = min(sizeof(rng_seed), strlen(rng_seed_hex) / 2);
	if (hex2bin(rng_seed, rng_seed_hex, len))
		return;

	add_bootloader_randomness(rng_seed, len);
	memzero_explicit(rng_seed, len);
	memzero_explicit(rng_seed_hex, len * 2);
}

void __init setup_arch(char **cmdline_p)
{
	cpu_probe();
	mips_cm_probe();
	prom_init();

	setup_early_fdc_console();
#ifdef CONFIG_EARLY_PRINTK
	setup_early_printk();
#endif
	cpu_report();
	if (IS_ENABLED(CONFIG_CPU_R4X00_BUGS64))
		check_bugs64_early();

#if defined(CONFIG_VT)
#if defined(CONFIG_VGA_CONSOLE)
	conswitchp = &vga_con;
#endif
#endif

	arch_mem_init(cmdline_p);
	dmi_setup();

	resource_init();
	plat_smp_setup();
	prefill_possible_map();

	cpu_cache_init();
	paging_init();

	memblock_dump_all();

	setup_rng_seed();
}

unsigned long kernelsp[NR_CPUS];
unsigned long fw_arg0, fw_arg1, fw_arg2, fw_arg3;

#ifdef CONFIG_DEBUG_FS
struct dentry *mips_debugfs_dir;
static int __init debugfs_mips(void)
{
	mips_debugfs_dir = debugfs_create_dir("mips", NULL);
	return 0;
}
arch_initcall(debugfs_mips);
#endif

#ifdef CONFIG_DMA_NONCOHERENT
static int __init setcoherentio(char *str)
{
	dma_default_coherent = true;
	pr_info("Hardware DMA cache coherency (command line)\n");
	return 0;
}
early_param("coherentio", setcoherentio);

static int __init setnocoherentio(char *str)
{
	dma_default_coherent = false;
	pr_info("Software DMA cache coherency (command line)\n");
	return 0;
}
early_param("nocoherentio", setnocoherentio);
#endif