summaryrefslogtreecommitdiff
path: root/arch/powerpc/kernel/setup-common.c
blob: 2add292da49432ee8db5ff5bad9b70871d7f4f48 (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
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Common boot and setup code for both 32-bit and 64-bit.
 * Extracted from arch/powerpc/kernel/setup_64.c.
 *
 * Copyright (C) 2001 PPC64 Team, IBM Corp
 */

#undef DEBUG

#include <linux/export.h>
#include <linux/panic_notifier.h>
#include <linux/string.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/reboot.h>
#include <linux/delay.h>
#include <linux/initrd.h>
#include <linux/platform_device.h>
#include <linux/printk.h>
#include <linux/seq_file.h>
#include <linux/ioport.h>
#include <linux/console.h>
#include <linux/root_dev.h>
#include <linux/cpu.h>
#include <linux/unistd.h>
#include <linux/seq_buf.h>
#include <linux/serial.h>
#include <linux/serial_8250.h>
#include <linux/percpu.h>
#include <linux/memblock.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/of_irq.h>
#include <linux/hugetlb.h>
#include <linux/pgtable.h>
#include <asm/io.h>
#include <asm/paca.h>
#include <asm/processor.h>
#include <asm/vdso_datapage.h>
#include <asm/smp.h>
#include <asm/elf.h>
#include <asm/machdep.h>
#include <asm/time.h>
#include <asm/cputable.h>
#include <asm/sections.h>
#include <asm/firmware.h>
#include <asm/btext.h>
#include <asm/nvram.h>
#include <asm/setup.h>
#include <asm/rtas.h>
#include <asm/iommu.h>
#include <asm/serial.h>
#include <asm/cache.h>
#include <asm/page.h>
#include <asm/mmu.h>
#include <asm/xmon.h>
#include <asm/cputhreads.h>
#include <mm/mmu_decl.h>
#include <asm/archrandom.h>
#include <asm/fadump.h>
#include <asm/udbg.h>
#include <asm/hugetlb.h>
#include <asm/livepatch.h>
#include <asm/mmu_context.h>
#include <asm/cpu_has_feature.h>
#include <asm/kasan.h>
#include <asm/mce.h>

#include "setup.h"

#ifdef DEBUG
#define DBG(fmt...) udbg_printf(fmt)
#else
#define DBG(fmt...)
#endif

/* The main machine-dep calls structure
 */
struct machdep_calls ppc_md;
EXPORT_SYMBOL(ppc_md);
struct machdep_calls *machine_id;
EXPORT_SYMBOL(machine_id);

int boot_cpuid = -1;
EXPORT_SYMBOL_GPL(boot_cpuid);
int __initdata boot_core_hwid = -1;

#ifdef CONFIG_PPC64
int boot_cpu_hwid = -1;
#endif

/*
 * These are used in binfmt_elf.c to put aux entries on the stack
 * for each elf executable being started.
 */
int dcache_bsize;
int icache_bsize;

/* Variables required to store legacy IO irq routing */
int of_i8042_kbd_irq;
EXPORT_SYMBOL_GPL(of_i8042_kbd_irq);
int of_i8042_aux_irq;
EXPORT_SYMBOL_GPL(of_i8042_aux_irq);

#ifdef __DO_IRQ_CANON
/* XXX should go elsewhere eventually */
int ppc_do_canonicalize_irqs;
EXPORT_SYMBOL(ppc_do_canonicalize_irqs);
#endif

#ifdef CONFIG_VMCORE_INFO
/* This keeps a track of which one is the crashing cpu. */
int crashing_cpu = -1;
#endif

/* also used by kexec */
void machine_shutdown(void)
{
	/*
	 * if fadump is active, cleanup the fadump registration before we
	 * shutdown.
	 */
	fadump_cleanup();

	if (ppc_md.machine_shutdown)
		ppc_md.machine_shutdown();
}

static void machine_hang(void)
{
	pr_emerg("System Halted, OK to turn off power\n");
	local_irq_disable();
	while (1)
		;
}

void machine_restart(char *cmd)
{
	machine_shutdown();
	if (ppc_md.restart)
		ppc_md.restart(cmd);

	smp_send_stop();

	do_kernel_restart(cmd);
	mdelay(1000);

	machine_hang();
}

void machine_power_off(void)
{
	machine_shutdown();
	do_kernel_power_off();
	smp_send_stop();
	machine_hang();
}
/* Used by the G5 thermal driver */
EXPORT_SYMBOL_GPL(machine_power_off);

void (*pm_power_off)(void);
EXPORT_SYMBOL_GPL(pm_power_off);

size_t __must_check arch_get_random_seed_longs(unsigned long *v, size_t max_longs)
{
	if (max_longs && ppc_md.get_random_seed && ppc_md.get_random_seed(v))
		return 1;
	return 0;
}
EXPORT_SYMBOL(arch_get_random_seed_longs);

void machine_halt(void)
{
	machine_shutdown();
	if (ppc_md.halt)
		ppc_md.halt();

	smp_send_stop();
	machine_hang();
}

#ifdef CONFIG_SMP
DEFINE_PER_CPU(unsigned int, cpu_pvr);
#endif

static void show_cpuinfo_summary(struct seq_file *m)
{
	struct device_node *root;
	const char *model = NULL;
	unsigned long bogosum = 0;
	int i;

	if (IS_ENABLED(CONFIG_SMP) && IS_ENABLED(CONFIG_PPC32)) {
		for_each_online_cpu(i)
			bogosum += loops_per_jiffy;
		seq_printf(m, "total bogomips\t: %lu.%02lu\n",
			   bogosum / (500000 / HZ), bogosum / (5000 / HZ) % 100);
	}
	seq_printf(m, "timebase\t: %lu\n", ppc_tb_freq);
	if (ppc_md.name)
		seq_printf(m, "platform\t: %s\n", ppc_md.name);
	root = of_find_node_by_path("/");
	if (root)
		model = of_get_property(root, "model", NULL);
	if (model)
		seq_printf(m, "model\t\t: %s\n", model);
	of_node_put(root);

	if (ppc_md.show_cpuinfo != NULL)
		ppc_md.show_cpuinfo(m);

	/* Display the amount of memory */
	if (IS_ENABLED(CONFIG_PPC32))
		seq_printf(m, "Memory\t\t: %d MB\n",
			   (unsigned int)(total_memory / (1024 * 1024)));
}

static int show_cpuinfo(struct seq_file *m, void *v)
{
	unsigned long cpu_id = (unsigned long)v - 1;
	unsigned int pvr;
	unsigned long proc_freq;
	unsigned short maj;
	unsigned short min;

#ifdef CONFIG_SMP
	pvr = per_cpu(cpu_pvr, cpu_id);
#else
	pvr = mfspr(SPRN_PVR);
#endif
	maj = (pvr >> 8) & 0xFF;
	min = pvr & 0xFF;

	seq_printf(m, "processor\t: %lu\ncpu\t\t: ", cpu_id);

	if (cur_cpu_spec->pvr_mask && cur_cpu_spec->cpu_name)
		seq_puts(m, cur_cpu_spec->cpu_name);
	else
		seq_printf(m, "unknown (%08x)", pvr);

	if (cpu_has_feature(CPU_FTR_ALTIVEC))
		seq_puts(m, ", altivec supported");

	seq_putc(m, '\n');

#ifdef CONFIG_TAU
	if (cpu_has_feature(CPU_FTR_TAU)) {
		if (IS_ENABLED(CONFIG_TAU_AVERAGE)) {
			/* more straightforward, but potentially misleading */
			seq_printf(m,  "temperature \t: %u C (uncalibrated)\n",
				   cpu_temp(cpu_id));
		} else {
			/* show the actual temp sensor range */
			u32 temp;
			temp = cpu_temp_both(cpu_id);
			seq_printf(m, "temperature \t: %u-%u C (uncalibrated)\n",
				   temp & 0xff, temp >> 16);
		}
	}
#endif /* CONFIG_TAU */

	/*
	 * Platforms that have variable clock rates, should implement
	 * the method ppc_md.get_proc_freq() that reports the clock
	 * rate of a given cpu. The rest can use ppc_proc_freq to
	 * report the clock rate that is same across all cpus.
	 */
	if (ppc_md.get_proc_freq)
		proc_freq = ppc_md.get_proc_freq(cpu_id);
	else
		proc_freq = ppc_proc_freq;

	if (proc_freq)
		seq_printf(m, "clock\t\t: %lu.%06luMHz\n",
			   proc_freq / 1000000, proc_freq % 1000000);

	/* If we are a Freescale core do a simple check so
	 * we don't have to keep adding cases in the future */
	if (PVR_VER(pvr) & 0x8000) {
		switch (PVR_VER(pvr)) {
		case 0x8000:	/* 7441/7450/7451, Voyager */
		case 0x8001:	/* 7445/7455, Apollo 6 */
		case 0x8002:	/* 7447/7457, Apollo 7 */
		case 0x8003:	/* 7447A, Apollo 7 PM */
		case 0x8004:	/* 7448, Apollo 8 */
		case 0x800c:	/* 7410, Nitro */
			maj = ((pvr >> 8) & 0xF);
			min = PVR_MIN(pvr);
			break;
		default:	/* e500/book-e */
			maj = PVR_MAJ(pvr);
			min = PVR_MIN(pvr);
			break;
		}
	} else {
		switch (PVR_VER(pvr)) {
			case 0x1008:	/* 740P/750P ?? */
				maj = ((pvr >> 8) & 0xFF) - 1;
				min = pvr & 0xFF;
				break;
			case 0x004e: /* POWER9 bits 12-15 give chip type */
			case 0x0080: /* POWER10 bit 12 gives SMT8/4 */
				maj = (pvr >> 8) & 0x0F;
				min = pvr & 0xFF;
				break;
			default:
				maj = (pvr >> 8) & 0xFF;
				min = pvr & 0xFF;
				break;
		}
	}

	seq_printf(m, "revision\t: %hd.%hd (pvr %04x %04x)\n",
		   maj, min, PVR_VER(pvr), PVR_REV(pvr));

	if (IS_ENABLED(CONFIG_PPC32))
		seq_printf(m, "bogomips\t: %lu.%02lu\n", loops_per_jiffy / (500000 / HZ),
			   (loops_per_jiffy / (5000 / HZ)) % 100);

	seq_putc(m, '\n');

	/* If this is the last cpu, print the summary */
	if (cpumask_next(cpu_id, cpu_online_mask) >= nr_cpu_ids)
		show_cpuinfo_summary(m);

	return 0;
}

static void *c_start(struct seq_file *m, loff_t *pos)
{
	if (*pos == 0)	/* just in case, cpu 0 is not the first */
		*pos = cpumask_first(cpu_online_mask);
	else
		*pos = cpumask_next(*pos - 1, cpu_online_mask);
	if ((*pos) < nr_cpu_ids)
		return (void *)(unsigned long)(*pos + 1);
	return NULL;
}

static void *c_next(struct seq_file *m, void *v, loff_t *pos)
{
	(*pos)++;
	return c_start(m, pos);
}

static void c_stop(struct seq_file *m, void *v)
{
}

const struct seq_operations cpuinfo_op = {
	.start	= c_start,
	.next	= c_next,
	.stop	= c_stop,
	.show	= show_cpuinfo,
};

void __init check_for_initrd(void)
{
#ifdef CONFIG_BLK_DEV_INITRD
	DBG(" -> check_for_initrd()  initrd_start=0x%lx  initrd_end=0x%lx\n",
	    initrd_start, initrd_end);

	/* If we were passed an initrd, set the ROOT_DEV properly if the values
	 * look sensible. If not, clear initrd reference.
	 */
	if (is_kernel_addr(initrd_start) && is_kernel_addr(initrd_end) &&
	    initrd_end > initrd_start)
		ROOT_DEV = Root_RAM0;
	else
		initrd_start = initrd_end = 0;

	if (initrd_start)
		pr_info("Found initrd at 0x%lx:0x%lx\n", initrd_start, initrd_end);

	DBG(" <- check_for_initrd()\n");
#endif /* CONFIG_BLK_DEV_INITRD */
}

#ifdef CONFIG_SMP

int threads_per_core, threads_per_subcore, threads_shift __read_mostly;
cpumask_t threads_core_mask __read_mostly;
EXPORT_SYMBOL_GPL(threads_per_core);
EXPORT_SYMBOL_GPL(threads_per_subcore);
EXPORT_SYMBOL_GPL(threads_shift);
EXPORT_SYMBOL_GPL(threads_core_mask);

static void __init cpu_init_thread_core_maps(int tpc)
{
	int i;

	threads_per_core = tpc;
	threads_per_subcore = tpc;
	cpumask_clear(&threads_core_mask);

	/* This implementation only supports power of 2 number of threads
	 * for simplicity and performance
	 */
	threads_shift = ilog2(tpc);
	BUG_ON(tpc != (1 << threads_shift));

	for (i = 0; i < tpc; i++)
		cpumask_set_cpu(i, &threads_core_mask);

	printk(KERN_INFO "CPU maps initialized for %d thread%s per core\n",
	       tpc, tpc > 1 ? "s" : "");
	printk(KERN_DEBUG " (thread shift is %d)\n", threads_shift);
}


u32 *cpu_to_phys_id = NULL;

static int assign_threads(unsigned int cpu, unsigned int nthreads, bool present,
			  const __be32 *hw_ids)
{
	for (int i = 0; i < nthreads && cpu < nr_cpu_ids; i++) {
		__be32 hwid;

		hwid = be32_to_cpu(hw_ids[i]);

		DBG("    thread %d -> cpu %d (hard id %d)\n", i, cpu, hwid);

		set_cpu_present(cpu, present);
		set_cpu_possible(cpu, true);
		cpu_to_phys_id[cpu] = hwid;
		cpu++;
	}

	return cpu;
}

/**
 * setup_cpu_maps - initialize the following cpu maps:
 *                  cpu_possible_mask
 *                  cpu_present_mask
 *
 * Having the possible map set up early allows us to restrict allocations
 * of things like irqstacks to nr_cpu_ids rather than NR_CPUS.
 *
 * We do not initialize the online map here; cpus set their own bits in
 * cpu_online_mask as they come up.
 *
 * This function is valid only for Open Firmware systems.  finish_device_tree
 * must be called before using this.
 *
 * While we're here, we may as well set the "physical" cpu ids in the paca.
 *
 * NOTE: This must match the parsing done in early_init_dt_scan_cpus.
 */
void __init smp_setup_cpu_maps(void)
{
	struct device_node *dn;
	int cpu = 0;
	int nthreads = 1;

	DBG("smp_setup_cpu_maps()\n");

	cpu_to_phys_id = memblock_alloc(nr_cpu_ids * sizeof(u32),
					__alignof__(u32));
	if (!cpu_to_phys_id)
		panic("%s: Failed to allocate %zu bytes align=0x%zx\n",
		      __func__, nr_cpu_ids * sizeof(u32), __alignof__(u32));

	for_each_node_by_type(dn, "cpu") {
		const __be32 *intserv;
		__be32 cpu_be;
		int len;

		DBG("  * %pOF...\n", dn);

		intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s",
				&len);
		if (intserv) {
			DBG("    ibm,ppc-interrupt-server#s -> %lu threads\n",
			    (len / sizeof(int)));
		} else {
			DBG("    no ibm,ppc-interrupt-server#s -> 1 thread\n");
			intserv = of_get_property(dn, "reg", &len);
			if (!intserv) {
				cpu_be = cpu_to_be32(cpu);
				/* XXX: what is this? uninitialized?? */
				intserv = &cpu_be;	/* assume logical == phys */
				len = 4;
			}
		}

		nthreads = len / sizeof(int);

		bool avail = of_device_is_available(dn);
		if (!avail)
			avail = !of_property_match_string(dn,
					"enable-method", "spin-table");

		if (boot_core_hwid >= 0) {
			if (cpu == 0) {
				pr_info("Skipping CPU node %pOF to allow for boot core.\n", dn);
				cpu = nthreads;
				continue;
			}

			if (be32_to_cpu(intserv[0]) == boot_core_hwid) {
				pr_info("Renumbered boot core %pOF to logical 0\n", dn);
				assign_threads(0, nthreads, avail, intserv);
				of_node_put(dn);
				break;
			}
		} else if (cpu >= nr_cpu_ids) {
			of_node_put(dn);
			break;
		}

		if (cpu < nr_cpu_ids)
			cpu = assign_threads(cpu, nthreads, avail, intserv);
	}

	/* If no SMT supported, nthreads is forced to 1 */
	if (!cpu_has_feature(CPU_FTR_SMT)) {
		DBG("  SMT disabled ! nthreads forced to 1\n");
		nthreads = 1;
	}

#ifdef CONFIG_PPC64
	/*
	 * On pSeries LPAR, we need to know how many cpus
	 * could possibly be added to this partition.
	 */
	if (firmware_has_feature(FW_FEATURE_LPAR) &&
	    (dn = of_find_node_by_path("/rtas"))) {
		int num_addr_cell, num_size_cell, maxcpus;
		const __be32 *ireg;

		num_addr_cell = of_n_addr_cells(dn);
		num_size_cell = of_n_size_cells(dn);

		ireg = of_get_property(dn, "ibm,lrdr-capacity", NULL);

		if (!ireg)
			goto out;

		maxcpus = be32_to_cpup(ireg + num_addr_cell + num_size_cell);

		/* Double maxcpus for processors which have SMT capability */
		if (cpu_has_feature(CPU_FTR_SMT))
			maxcpus *= nthreads;

		if (maxcpus > nr_cpu_ids) {
			printk(KERN_WARNING
			       "Partition configured for %d cpus, "
			       "operating system maximum is %u.\n",
			       maxcpus, nr_cpu_ids);
			maxcpus = nr_cpu_ids;
		} else
			printk(KERN_INFO "Partition configured for %d cpus.\n",
			       maxcpus);

		for (cpu = 0; cpu < maxcpus; cpu++)
			set_cpu_possible(cpu, true);
	out:
		of_node_put(dn);
	}
	vdso_data->processorCount = num_present_cpus();
#endif /* CONFIG_PPC64 */

        /* Initialize CPU <=> thread mapping/
	 *
	 * WARNING: We assume that the number of threads is the same for
	 * every CPU in the system. If that is not the case, then some code
	 * here will have to be reworked
	 */
	cpu_init_thread_core_maps(nthreads);

	/* Now that possible cpus are set, set nr_cpu_ids for later use */
	setup_nr_cpu_ids();

	free_unused_pacas();
}
#endif /* CONFIG_SMP */

#ifdef CONFIG_PCSPKR_PLATFORM
static __init int add_pcspkr(void)
{
	struct device_node *np;
	struct platform_device *pd;
	int ret;

	np = of_find_compatible_node(NULL, NULL, "pnpPNP,100");
	of_node_put(np);
	if (!np)
		return -ENODEV;

	pd = platform_device_alloc("pcspkr", -1);
	if (!pd)
		return -ENOMEM;

	ret = platform_device_add(pd);
	if (ret)
		platform_device_put(pd);

	return ret;
}
device_initcall(add_pcspkr);
#endif	/* CONFIG_PCSPKR_PLATFORM */

static char ppc_hw_desc_buf[128] __initdata;

struct seq_buf ppc_hw_desc __initdata = {
	.buffer = ppc_hw_desc_buf,
	.size = sizeof(ppc_hw_desc_buf),
	.len = 0,
};

static __init void probe_machine(void)
{
	extern struct machdep_calls __machine_desc_start;
	extern struct machdep_calls __machine_desc_end;
	unsigned int i;

	/*
	 * Iterate all ppc_md structures until we find the proper
	 * one for the current machine type
	 */
	DBG("Probing machine type ...\n");

	/*
	 * Check ppc_md is empty, if not we have a bug, ie, we setup an
	 * entry before probe_machine() which will be overwritten
	 */
	for (i = 0; i < (sizeof(ppc_md) / sizeof(void *)); i++) {
		if (((void **)&ppc_md)[i]) {
			printk(KERN_ERR "Entry %d in ppc_md non empty before"
			       " machine probe !\n", i);
		}
	}

	for (machine_id = &__machine_desc_start;
	     machine_id < &__machine_desc_end;
	     machine_id++) {
		DBG("  %s ...\n", machine_id->name);
		if (machine_id->compatible && !of_machine_is_compatible(machine_id->compatible))
			continue;
		if (machine_id->compatibles && !of_machine_compatible_match(machine_id->compatibles))
			continue;
		memcpy(&ppc_md, machine_id, sizeof(struct machdep_calls));
		if (ppc_md.probe && !ppc_md.probe())
			continue;
		DBG("   %s match !\n", machine_id->name);
		break;
	}
	/* What can we do if we didn't find ? */
	if (machine_id >= &__machine_desc_end) {
		pr_err("No suitable machine description found !\n");
		for (;;);
	}

	// Append the machine name to other info we've gathered
	seq_buf_puts(&ppc_hw_desc, ppc_md.name);

	// Set the generic hardware description shown in oopses
	dump_stack_set_arch_desc(ppc_hw_desc.buffer);

	pr_info("Hardware name: %s\n", ppc_hw_desc.buffer);
}

/* Match a class of boards, not a specific device configuration. */
int check_legacy_ioport(unsigned long base_port)
{
	struct device_node *parent, *np = NULL;
	int ret = -ENODEV;

	switch(base_port) {
	case I8042_DATA_REG:
		if (!(np = of_find_compatible_node(NULL, NULL, "pnpPNP,303")))
			np = of_find_compatible_node(NULL, NULL, "pnpPNP,f03");
		if (np) {
			parent = of_get_parent(np);

			of_i8042_kbd_irq = irq_of_parse_and_map(parent, 0);
			if (!of_i8042_kbd_irq)
				of_i8042_kbd_irq = 1;

			of_i8042_aux_irq = irq_of_parse_and_map(parent, 1);
			if (!of_i8042_aux_irq)
				of_i8042_aux_irq = 12;

			of_node_put(np);
			np = parent;
			break;
		}
		np = of_find_node_by_type(NULL, "8042");
		/* Pegasos has no device_type on its 8042 node, look for the
		 * name instead */
		if (!np)
			np = of_find_node_by_name(NULL, "8042");
		if (np) {
			of_i8042_kbd_irq = 1;
			of_i8042_aux_irq = 12;
		}
		break;
	case FDC_BASE: /* FDC1 */
		np = of_find_node_by_type(NULL, "fdc");
		break;
	default:
		/* ipmi is supposed to fail here */
		break;
	}
	if (!np)
		return ret;
	parent = of_get_parent(np);
	if (parent) {
		if (of_node_is_type(parent, "isa"))
			ret = 0;
		of_node_put(parent);
	}
	of_node_put(np);
	return ret;
}
EXPORT_SYMBOL(check_legacy_ioport);

/*
 * Panic notifiers setup
 *
 * We have 3 notifiers for powerpc, each one from a different "nature":
 *
 * - ppc_panic_fadump_handler() is a hypervisor notifier, which hard-disables
 *   IRQs and deal with the Firmware-Assisted dump, when it is configured;
 *   should run early in the panic path.
 *
 * - dump_kernel_offset() is an informative notifier, just showing the KASLR
 *   offset if we have RANDOMIZE_BASE set.
 *
 * - ppc_panic_platform_handler() is a low-level handler that's registered
 *   only if the platform wishes to perform final actions in the panic path,
 *   hence it should run late and might not even return. Currently, only
 *   pseries and ps3 platforms register callbacks.
 */
static int ppc_panic_fadump_handler(struct notifier_block *this,
				    unsigned long event, void *ptr)
{
	/*
	 * panic does a local_irq_disable, but we really
	 * want interrupts to be hard disabled.
	 */
	hard_irq_disable();

	/*
	 * If firmware-assisted dump has been registered then trigger
	 * its callback and let the firmware handles everything else.
	 */
	crash_fadump(NULL, ptr);

	return NOTIFY_DONE;
}

static int dump_kernel_offset(struct notifier_block *self, unsigned long v,
			      void *p)
{
	pr_emerg("Kernel Offset: 0x%lx from 0x%lx\n",
		 kaslr_offset(), KERNELBASE);

	return NOTIFY_DONE;
}

static int ppc_panic_platform_handler(struct notifier_block *this,
				      unsigned long event, void *ptr)
{
	/*
	 * This handler is only registered if we have a panic callback
	 * on ppc_md, hence NULL check is not needed.
	 * Also, it may not return, so it runs really late on panic path.
	 */
	ppc_md.panic(ptr);

	return NOTIFY_DONE;
}

static struct notifier_block ppc_fadump_block = {
	.notifier_call = ppc_panic_fadump_handler,
	.priority = INT_MAX, /* run early, to notify the firmware ASAP */
};

static struct notifier_block kernel_offset_notifier = {
	.notifier_call = dump_kernel_offset,
};

static struct notifier_block ppc_panic_block = {
	.notifier_call = ppc_panic_platform_handler,
	.priority = INT_MIN, /* may not return; must be done last */
};

void __init setup_panic(void)
{
	/* Hard-disables IRQs + deal with FW-assisted dump (fadump) */
	atomic_notifier_chain_register(&panic_notifier_list,
				       &ppc_fadump_block);

	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_offset() > 0)
		atomic_notifier_chain_register(&panic_notifier_list,
					       &kernel_offset_notifier);

	/* Low-level platform-specific routines that should run on panic */
	if (ppc_md.panic)
		atomic_notifier_chain_register(&panic_notifier_list,
					       &ppc_panic_block);
}

#ifdef CONFIG_CHECK_CACHE_COHERENCY
/*
 * For platforms that have configurable cache-coherency.  This function
 * checks that the cache coherency setting of the kernel matches the setting
 * left by the firmware, as indicated in the device tree.  Since a mismatch
 * will eventually result in DMA failures, we print * and error and call
 * BUG() in that case.
 */

#define KERNEL_COHERENCY	(!IS_ENABLED(CONFIG_NOT_COHERENT_CACHE))

static int __init check_cache_coherency(void)
{
	struct device_node *np;
	const void *prop;
	bool devtree_coherency;

	np = of_find_node_by_path("/");
	prop = of_get_property(np, "coherency-off", NULL);
	of_node_put(np);

	devtree_coherency = prop ? false : true;

	if (devtree_coherency != KERNEL_COHERENCY) {
		printk(KERN_ERR
			"kernel coherency:%s != device tree_coherency:%s\n",
			KERNEL_COHERENCY ? "on" : "off",
			devtree_coherency ? "on" : "off");
		BUG();
	}

	return 0;
}

late_initcall(check_cache_coherency);
#endif /* CONFIG_CHECK_CACHE_COHERENCY */

void ppc_printk_progress(char *s, unsigned short hex)
{
	pr_info("%s\n", s);
}

static __init void print_system_info(void)
{
	pr_info("-----------------------------------------------------\n");
	pr_info("phys_mem_size     = 0x%llx\n",
		(unsigned long long)memblock_phys_mem_size());

	pr_info("dcache_bsize      = 0x%x\n", dcache_bsize);
	pr_info("icache_bsize      = 0x%x\n", icache_bsize);

	pr_info("cpu_features      = 0x%016lx\n", cur_cpu_spec->cpu_features);
	pr_info("  possible        = 0x%016lx\n",
		(unsigned long)CPU_FTRS_POSSIBLE);
	pr_info("  always          = 0x%016lx\n",
		(unsigned long)CPU_FTRS_ALWAYS);
	pr_info("cpu_user_features = 0x%08x 0x%08x\n",
		cur_cpu_spec->cpu_user_features,
		cur_cpu_spec->cpu_user_features2);
	pr_info("mmu_features      = 0x%08x\n", cur_cpu_spec->mmu_features);
#ifdef CONFIG_PPC64
	pr_info("firmware_features = 0x%016lx\n", powerpc_firmware_features);
#ifdef CONFIG_PPC_BOOK3S
	pr_info("vmalloc start     = 0x%lx\n", KERN_VIRT_START);
	pr_info("IO start          = 0x%lx\n", KERN_IO_START);
	pr_info("vmemmap start     = 0x%lx\n", (unsigned long)vmemmap);
#endif
#endif

	if (!early_radix_enabled())
		print_system_hash_info();

	if (PHYSICAL_START > 0)
		pr_info("physical_start    = 0x%llx\n",
		       (unsigned long long)PHYSICAL_START);
	pr_info("-----------------------------------------------------\n");
}

#ifdef CONFIG_SMP
static void __init smp_setup_pacas(void)
{
	int cpu;

	for_each_possible_cpu(cpu) {
		if (cpu == smp_processor_id())
			continue;
		allocate_paca(cpu);
		set_hard_smp_processor_id(cpu, cpu_to_phys_id[cpu]);
	}

	memblock_free(cpu_to_phys_id, nr_cpu_ids * sizeof(u32));
	cpu_to_phys_id = NULL;
}
#endif

/*
 * Called into from start_kernel this initializes memblock, which is used
 * to manage page allocation until mem_init is called.
 */
void __init setup_arch(char **cmdline_p)
{
	kasan_init();

	*cmdline_p = boot_command_line;

	/* Set a half-reasonable default so udelay does something sensible */
	loops_per_jiffy = 500000000 / HZ;

	/* Unflatten the device-tree passed by prom_init or kexec */
	unflatten_device_tree();

	/*
	 * Initialize cache line/block info from device-tree (on ppc64) or
	 * just cputable (on ppc32).
	 */
	initialize_cache_info();

	/* Initialize RTAS if available. */
	rtas_initialize();

	/* Check if we have an initrd provided via the device-tree. */
	check_for_initrd();

	/* Probe the machine type, establish ppc_md. */
	probe_machine();

	/* Setup panic notifier if requested by the platform. */
	setup_panic();

	/*
	 * Configure ppc_md.power_save (ppc32 only, 64-bit machines do
	 * it from their respective probe() function.
	 */
	setup_power_save();

	/* Discover standard serial ports. */
	find_legacy_serial_ports();

	/* Register early console with the printk subsystem. */
	register_early_udbg_console();

	/* Setup the various CPU maps based on the device-tree. */
	smp_setup_cpu_maps();

	/* Initialize xmon. */
	xmon_setup();

	/* Check the SMT related command line arguments (ppc64). */
	check_smt_enabled();

	/* Parse memory topology */
	mem_topology_setup();
	/* Set max_mapnr before paging_init() */
	set_max_mapnr(max_pfn);

	/*
	 * Release secondary cpus out of their spinloops at 0x60 now that
	 * we can map physical -> logical CPU ids.
	 *
	 * Freescale Book3e parts spin in a loop provided by firmware,
	 * so smp_release_cpus() does nothing for them.
	 */
#ifdef CONFIG_SMP
	smp_setup_pacas();

	/* On BookE, setup per-core TLB data structures. */
	setup_tlb_core_data();
#endif

	/* Print various info about the machine that has been gathered so far. */
	print_system_info();

	klp_init_thread_info(&init_task);

	setup_initial_init_mm(_stext, _etext, _edata, _end);
	/* sched_init() does the mmgrab(&init_mm) for the primary CPU */
	VM_WARN_ON(cpumask_test_cpu(smp_processor_id(), mm_cpumask(&init_mm)));
	cpumask_set_cpu(smp_processor_id(), mm_cpumask(&init_mm));
	inc_mm_active_cpus(&init_mm);
	mm_iommu_init(&init_mm);

	irqstack_early_init();
	exc_lvl_early_init();
	emergency_stack_init();

	mce_init();
	smp_release_cpus();

	initmem_init();

	/*
	 * Reserve large chunks of memory for use by CMA for KVM and hugetlb. These must
	 * be called after initmem_init(), so that pageblock_order is initialised.
	 */
	kvm_cma_reserve();
	gigantic_hugetlb_cma_reserve();

	early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT);

	if (ppc_md.setup_arch)
		ppc_md.setup_arch();

	setup_barrier_nospec();
	setup_spectre_v2();

	paging_init();

	/* Initialize the MMU context management stuff. */
	mmu_context_init();

	/* Interrupt code needs to be 64K-aligned. */
	if (IS_ENABLED(CONFIG_PPC64) && (unsigned long)_stext & 0xffff)
		panic("Kernelbase not 64K-aligned (0x%lx)!\n",
		      (unsigned long)_stext);
}