xref: /linux/arch/x86/kernel/setup.c (revision 00c010e130e58301db2ea0cec1eadc931e1cb8cf)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  Copyright (C) 1995  Linus Torvalds
4  *
5  * This file contains the setup_arch() code, which handles the architecture-dependent
6  * parts of early kernel initialization.
7  */
8 #include <linux/acpi.h>
9 #include <linux/console.h>
10 #include <linux/cpu.h>
11 #include <linux/crash_dump.h>
12 #include <linux/dma-map-ops.h>
13 #include <linux/efi.h>
14 #include <linux/hugetlb.h>
15 #include <linux/ima.h>
16 #include <linux/init_ohci1394_dma.h>
17 #include <linux/initrd.h>
18 #include <linux/iscsi_ibft.h>
19 #include <linux/memblock.h>
20 #include <linux/panic_notifier.h>
21 #include <linux/pci.h>
22 #include <linux/random.h>
23 #include <linux/root_dev.h>
24 #include <linux/static_call.h>
25 #include <linux/swiotlb.h>
26 #include <linux/tboot.h>
27 #include <linux/usb/xhci-dbgp.h>
28 #include <linux/vmalloc.h>
29 
30 #include <uapi/linux/mount.h>
31 
32 #include <xen/xen.h>
33 
34 #include <asm/apic.h>
35 #include <asm/bios_ebda.h>
36 #include <asm/bugs.h>
37 #include <asm/cacheinfo.h>
38 #include <asm/coco.h>
39 #include <asm/cpu.h>
40 #include <asm/efi.h>
41 #include <asm/gart.h>
42 #include <asm/hypervisor.h>
43 #include <asm/io_apic.h>
44 #include <asm/kasan.h>
45 #include <asm/kaslr.h>
46 #include <asm/mce.h>
47 #include <asm/memtype.h>
48 #include <asm/mtrr.h>
49 #include <asm/nmi.h>
50 #include <asm/numa.h>
51 #include <asm/olpc_ofw.h>
52 #include <asm/pci-direct.h>
53 #include <asm/prom.h>
54 #include <asm/proto.h>
55 #include <asm/realmode.h>
56 #include <asm/thermal.h>
57 #include <asm/unwind.h>
58 #include <asm/vsyscall.h>
59 
60 /*
61  * max_low_pfn_mapped: highest directly mapped pfn < 4 GB
62  * max_pfn_mapped:     highest directly mapped pfn > 4 GB
63  *
64  * The direct mapping only covers E820_TYPE_RAM regions, so the ranges and gaps are
65  * represented by pfn_mapped[].
66  */
67 unsigned long max_low_pfn_mapped;
68 unsigned long max_pfn_mapped;
69 
70 #ifdef CONFIG_DMI
71 RESERVE_BRK(dmi_alloc, 65536);
72 #endif
73 
74 
75 unsigned long _brk_start = (unsigned long)__brk_base;
76 unsigned long _brk_end   = (unsigned long)__brk_base;
77 
78 struct boot_params boot_params;
79 
80 /*
81  * These are the four main kernel memory regions, we put them into
82  * the resource tree so that kdump tools and other debugging tools
83  * recover it:
84  */
85 
86 static struct resource rodata_resource = {
87 	.name	= "Kernel rodata",
88 	.start	= 0,
89 	.end	= 0,
90 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
91 };
92 
93 static struct resource data_resource = {
94 	.name	= "Kernel data",
95 	.start	= 0,
96 	.end	= 0,
97 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
98 };
99 
100 static struct resource code_resource = {
101 	.name	= "Kernel code",
102 	.start	= 0,
103 	.end	= 0,
104 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
105 };
106 
107 static struct resource bss_resource = {
108 	.name	= "Kernel bss",
109 	.start	= 0,
110 	.end	= 0,
111 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
112 };
113 
114 
115 #ifdef CONFIG_X86_32
116 /* CPU data as detected by the assembly code in head_32.S */
117 struct cpuinfo_x86 new_cpu_data;
118 
119 struct apm_info apm_info;
120 EXPORT_SYMBOL(apm_info);
121 
122 #if defined(CONFIG_X86_SPEEDSTEP_SMI) || \
123 	defined(CONFIG_X86_SPEEDSTEP_SMI_MODULE)
124 struct ist_info ist_info;
125 EXPORT_SYMBOL(ist_info);
126 #else
127 struct ist_info ist_info;
128 #endif
129 
130 #endif
131 
132 struct cpuinfo_x86 boot_cpu_data __read_mostly;
133 EXPORT_SYMBOL(boot_cpu_data);
134 SYM_PIC_ALIAS(boot_cpu_data);
135 
136 #if !defined(CONFIG_X86_PAE) || defined(CONFIG_X86_64)
137 __visible unsigned long mmu_cr4_features __ro_after_init;
138 #else
139 __visible unsigned long mmu_cr4_features __ro_after_init = X86_CR4_PAE;
140 #endif
141 
142 #ifdef CONFIG_IMA
143 static phys_addr_t ima_kexec_buffer_phys;
144 static size_t ima_kexec_buffer_size;
145 #endif
146 
147 /* Boot loader ID and version as integers, for the benefit of proc_dointvec */
148 int bootloader_type, bootloader_version;
149 
150 static const struct ctl_table x86_sysctl_table[] = {
151 	{
152 		.procname       = "unknown_nmi_panic",
153 		.data           = &unknown_nmi_panic,
154 		.maxlen         = sizeof(int),
155 		.mode           = 0644,
156 		.proc_handler   = proc_dointvec,
157 	},
158 	{
159 		.procname	= "panic_on_unrecovered_nmi",
160 		.data		= &panic_on_unrecovered_nmi,
161 		.maxlen		= sizeof(int),
162 		.mode		= 0644,
163 		.proc_handler	= proc_dointvec,
164 	},
165 	{
166 		.procname	= "panic_on_io_nmi",
167 		.data		= &panic_on_io_nmi,
168 		.maxlen		= sizeof(int),
169 		.mode		= 0644,
170 		.proc_handler	= proc_dointvec,
171 	},
172 	{
173 		.procname	= "bootloader_type",
174 		.data		= &bootloader_type,
175 		.maxlen		= sizeof(int),
176 		.mode		= 0444,
177 		.proc_handler	= proc_dointvec,
178 	},
179 	{
180 		.procname	= "bootloader_version",
181 		.data		= &bootloader_version,
182 		.maxlen		= sizeof(int),
183 		.mode		= 0444,
184 		.proc_handler	= proc_dointvec,
185 	},
186 	{
187 		.procname	= "io_delay_type",
188 		.data		= &io_delay_type,
189 		.maxlen		= sizeof(int),
190 		.mode		= 0644,
191 		.proc_handler	= proc_dointvec,
192 	},
193 #if defined(CONFIG_ACPI_SLEEP)
194 	{
195 		.procname	= "acpi_video_flags",
196 		.data		= &acpi_realmode_flags,
197 		.maxlen		= sizeof(unsigned long),
198 		.mode		= 0644,
199 		.proc_handler	= proc_doulongvec_minmax,
200 	},
201 #endif
202 };
203 
init_x86_sysctl(void)204 static int __init init_x86_sysctl(void)
205 {
206 	register_sysctl_init("kernel", x86_sysctl_table);
207 	return 0;
208 }
209 arch_initcall(init_x86_sysctl);
210 
211 /*
212  * Setup options
213  */
214 struct screen_info screen_info;
215 EXPORT_SYMBOL(screen_info);
216 struct edid_info edid_info;
217 EXPORT_SYMBOL_GPL(edid_info);
218 
219 extern int root_mountflags;
220 
221 unsigned long saved_video_mode;
222 
223 #define RAMDISK_IMAGE_START_MASK	0x07FF
224 #define RAMDISK_PROMPT_FLAG		0x8000
225 #define RAMDISK_LOAD_FLAG		0x4000
226 
227 static char __initdata command_line[COMMAND_LINE_SIZE];
228 #ifdef CONFIG_CMDLINE_BOOL
229 char builtin_cmdline[COMMAND_LINE_SIZE] = CONFIG_CMDLINE;
230 bool builtin_cmdline_added __ro_after_init;
231 #endif
232 
233 #if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
234 struct edd edd;
235 #ifdef CONFIG_EDD_MODULE
236 EXPORT_SYMBOL(edd);
237 #endif
238 /**
239  * copy_edd() - Copy the BIOS EDD information
240  *              from boot_params into a safe place.
241  *
242  */
copy_edd(void)243 static inline void __init copy_edd(void)
244 {
245      memcpy(edd.mbr_signature, boot_params.edd_mbr_sig_buffer,
246 	    sizeof(edd.mbr_signature));
247      memcpy(edd.edd_info, boot_params.eddbuf, sizeof(edd.edd_info));
248      edd.mbr_signature_nr = boot_params.edd_mbr_sig_buf_entries;
249      edd.edd_info_nr = boot_params.eddbuf_entries;
250 }
251 #else
copy_edd(void)252 static inline void __init copy_edd(void)
253 {
254 }
255 #endif
256 
extend_brk(size_t size,size_t align)257 void * __init extend_brk(size_t size, size_t align)
258 {
259 	size_t mask = align - 1;
260 	void *ret;
261 
262 	BUG_ON(_brk_start == 0);
263 	BUG_ON(align & mask);
264 
265 	_brk_end = (_brk_end + mask) & ~mask;
266 	BUG_ON((char *)(_brk_end + size) > __brk_limit);
267 
268 	ret = (void *)_brk_end;
269 	_brk_end += size;
270 
271 	memset(ret, 0, size);
272 
273 	return ret;
274 }
275 
276 #ifdef CONFIG_X86_32
cleanup_highmap(void)277 static void __init cleanup_highmap(void)
278 {
279 }
280 #endif
281 
reserve_brk(void)282 static void __init reserve_brk(void)
283 {
284 	if (_brk_end > _brk_start)
285 		memblock_reserve_kern(__pa_symbol(_brk_start),
286 				      _brk_end - _brk_start);
287 
288 	/* Mark brk area as locked down and no longer taking any
289 	   new allocations */
290 	_brk_start = 0;
291 }
292 
293 #ifdef CONFIG_BLK_DEV_INITRD
294 
get_ramdisk_image(void)295 static u64 __init get_ramdisk_image(void)
296 {
297 	u64 ramdisk_image = boot_params.hdr.ramdisk_image;
298 
299 	ramdisk_image |= (u64)boot_params.ext_ramdisk_image << 32;
300 
301 	if (ramdisk_image == 0)
302 		ramdisk_image = phys_initrd_start;
303 
304 	return ramdisk_image;
305 }
get_ramdisk_size(void)306 static u64 __init get_ramdisk_size(void)
307 {
308 	u64 ramdisk_size = boot_params.hdr.ramdisk_size;
309 
310 	ramdisk_size |= (u64)boot_params.ext_ramdisk_size << 32;
311 
312 	if (ramdisk_size == 0)
313 		ramdisk_size = phys_initrd_size;
314 
315 	return ramdisk_size;
316 }
317 
relocate_initrd(void)318 static void __init relocate_initrd(void)
319 {
320 	/* Assume only end is not page aligned */
321 	u64 ramdisk_image = get_ramdisk_image();
322 	u64 ramdisk_size  = get_ramdisk_size();
323 	u64 area_size     = PAGE_ALIGN(ramdisk_size);
324 	int ret = 0;
325 
326 	/* We need to move the initrd down into directly mapped mem */
327 	u64 relocated_ramdisk = memblock_phys_alloc_range(area_size, PAGE_SIZE, 0,
328 						      PFN_PHYS(max_pfn_mapped));
329 	if (!relocated_ramdisk)
330 		panic("Cannot find place for new RAMDISK of size %lld\n",
331 		      ramdisk_size);
332 
333 	initrd_start = relocated_ramdisk + PAGE_OFFSET;
334 	initrd_end   = initrd_start + ramdisk_size;
335 	printk(KERN_INFO "Allocated new RAMDISK: [mem %#010llx-%#010llx]\n",
336 	       relocated_ramdisk, relocated_ramdisk + ramdisk_size - 1);
337 
338 	ret = copy_from_early_mem((void *)initrd_start, ramdisk_image, ramdisk_size);
339 	if (ret)
340 		panic("Copy RAMDISK failed\n");
341 
342 	printk(KERN_INFO "Move RAMDISK from [mem %#010llx-%#010llx] to"
343 		" [mem %#010llx-%#010llx]\n",
344 		ramdisk_image, ramdisk_image + ramdisk_size - 1,
345 		relocated_ramdisk, relocated_ramdisk + ramdisk_size - 1);
346 }
347 
early_reserve_initrd(void)348 static void __init early_reserve_initrd(void)
349 {
350 	/* Assume only end is not page aligned */
351 	u64 ramdisk_image = get_ramdisk_image();
352 	u64 ramdisk_size  = get_ramdisk_size();
353 	u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
354 
355 	if (!boot_params.hdr.type_of_loader ||
356 	    !ramdisk_image || !ramdisk_size)
357 		return;		/* No initrd provided by bootloader */
358 
359 	memblock_reserve_kern(ramdisk_image, ramdisk_end - ramdisk_image);
360 }
361 
reserve_initrd(void)362 static void __init reserve_initrd(void)
363 {
364 	/* Assume only end is not page aligned */
365 	u64 ramdisk_image = get_ramdisk_image();
366 	u64 ramdisk_size  = get_ramdisk_size();
367 	u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
368 
369 	if (!boot_params.hdr.type_of_loader ||
370 	    !ramdisk_image || !ramdisk_size)
371 		return;		/* No initrd provided by bootloader */
372 
373 	initrd_start = 0;
374 
375 	printk(KERN_INFO "RAMDISK: [mem %#010llx-%#010llx]\n", ramdisk_image,
376 			ramdisk_end - 1);
377 
378 	if (pfn_range_is_mapped(PFN_DOWN(ramdisk_image),
379 				PFN_DOWN(ramdisk_end))) {
380 		/* All are mapped, easy case */
381 		initrd_start = ramdisk_image + PAGE_OFFSET;
382 		initrd_end = initrd_start + ramdisk_size;
383 		return;
384 	}
385 
386 	relocate_initrd();
387 
388 	memblock_phys_free(ramdisk_image, ramdisk_end - ramdisk_image);
389 }
390 
391 #else
early_reserve_initrd(void)392 static void __init early_reserve_initrd(void)
393 {
394 }
reserve_initrd(void)395 static void __init reserve_initrd(void)
396 {
397 }
398 #endif /* CONFIG_BLK_DEV_INITRD */
399 
add_early_ima_buffer(u64 phys_addr)400 static void __init add_early_ima_buffer(u64 phys_addr)
401 {
402 #ifdef CONFIG_IMA
403 	struct ima_setup_data *data;
404 
405 	data = early_memremap(phys_addr + sizeof(struct setup_data), sizeof(*data));
406 	if (!data) {
407 		pr_warn("setup: failed to memremap ima_setup_data entry\n");
408 		return;
409 	}
410 
411 	if (data->size) {
412 		memblock_reserve_kern(data->addr, data->size);
413 		ima_kexec_buffer_phys = data->addr;
414 		ima_kexec_buffer_size = data->size;
415 	}
416 
417 	early_memunmap(data, sizeof(*data));
418 #else
419 	pr_warn("Passed IMA kexec data, but CONFIG_IMA not set. Ignoring.\n");
420 #endif
421 }
422 
423 #if defined(CONFIG_HAVE_IMA_KEXEC) && !defined(CONFIG_OF_FLATTREE)
ima_free_kexec_buffer(void)424 int __init ima_free_kexec_buffer(void)
425 {
426 	if (!ima_kexec_buffer_size)
427 		return -ENOENT;
428 
429 	memblock_free_late(ima_kexec_buffer_phys,
430 			   ima_kexec_buffer_size);
431 
432 	ima_kexec_buffer_phys = 0;
433 	ima_kexec_buffer_size = 0;
434 
435 	return 0;
436 }
437 
ima_get_kexec_buffer(void ** addr,size_t * size)438 int __init ima_get_kexec_buffer(void **addr, size_t *size)
439 {
440 	if (!ima_kexec_buffer_size)
441 		return -ENOENT;
442 
443 	*addr = __va(ima_kexec_buffer_phys);
444 	*size = ima_kexec_buffer_size;
445 
446 	return 0;
447 }
448 #endif
449 
add_kho(u64 phys_addr,u32 data_len)450 static void __init add_kho(u64 phys_addr, u32 data_len)
451 {
452 	struct kho_data *kho;
453 	u64 addr = phys_addr + sizeof(struct setup_data);
454 	u64 size = data_len - sizeof(struct setup_data);
455 
456 	if (!IS_ENABLED(CONFIG_KEXEC_HANDOVER)) {
457 		pr_warn("Passed KHO data, but CONFIG_KEXEC_HANDOVER not set. Ignoring.\n");
458 		return;
459 	}
460 
461 	kho = early_memremap(addr, size);
462 	if (!kho) {
463 		pr_warn("setup: failed to memremap kho data (0x%llx, 0x%llx)\n",
464 			addr, size);
465 		return;
466 	}
467 
468 	kho_populate(kho->fdt_addr, kho->fdt_size, kho->scratch_addr, kho->scratch_size);
469 
470 	early_memunmap(kho, size);
471 }
472 
parse_setup_data(void)473 static void __init parse_setup_data(void)
474 {
475 	struct setup_data *data;
476 	u64 pa_data, pa_next;
477 
478 	pa_data = boot_params.hdr.setup_data;
479 	while (pa_data) {
480 		u32 data_len, data_type;
481 
482 		data = early_memremap(pa_data, sizeof(*data));
483 		data_len = data->len + sizeof(struct setup_data);
484 		data_type = data->type;
485 		pa_next = data->next;
486 		early_memunmap(data, sizeof(*data));
487 
488 		switch (data_type) {
489 		case SETUP_E820_EXT:
490 			e820__memory_setup_extended(pa_data, data_len);
491 			break;
492 		case SETUP_DTB:
493 			add_dtb(pa_data);
494 			break;
495 		case SETUP_EFI:
496 			parse_efi_setup(pa_data, data_len);
497 			break;
498 		case SETUP_IMA:
499 			add_early_ima_buffer(pa_data);
500 			break;
501 		case SETUP_KEXEC_KHO:
502 			add_kho(pa_data, data_len);
503 			break;
504 		case SETUP_RNG_SEED:
505 			data = early_memremap(pa_data, data_len);
506 			add_bootloader_randomness(data->data, data->len);
507 			/* Zero seed for forward secrecy. */
508 			memzero_explicit(data->data, data->len);
509 			/* Zero length in case we find ourselves back here by accident. */
510 			memzero_explicit(&data->len, sizeof(data->len));
511 			early_memunmap(data, data_len);
512 			break;
513 		default:
514 			break;
515 		}
516 		pa_data = pa_next;
517 	}
518 }
519 
520 /*
521  * Translate the fields of 'struct boot_param' into global variables
522  * representing these parameters.
523  */
parse_boot_params(void)524 static void __init parse_boot_params(void)
525 {
526 	ROOT_DEV = old_decode_dev(boot_params.hdr.root_dev);
527 	screen_info = boot_params.screen_info;
528 	edid_info = boot_params.edid_info;
529 #ifdef CONFIG_X86_32
530 	apm_info.bios = boot_params.apm_bios_info;
531 	ist_info = boot_params.ist_info;
532 #endif
533 	saved_video_mode = boot_params.hdr.vid_mode;
534 	bootloader_type = boot_params.hdr.type_of_loader;
535 	if ((bootloader_type >> 4) == 0xe) {
536 		bootloader_type &= 0xf;
537 		bootloader_type |= (boot_params.hdr.ext_loader_type+0x10) << 4;
538 	}
539 	bootloader_version  = bootloader_type & 0xf;
540 	bootloader_version |= boot_params.hdr.ext_loader_ver << 4;
541 
542 #ifdef CONFIG_BLK_DEV_RAM
543 	rd_image_start = boot_params.hdr.ram_size & RAMDISK_IMAGE_START_MASK;
544 #endif
545 #ifdef CONFIG_EFI
546 	if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
547 		     EFI32_LOADER_SIGNATURE, 4)) {
548 		set_bit(EFI_BOOT, &efi.flags);
549 	} else if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
550 		     EFI64_LOADER_SIGNATURE, 4)) {
551 		set_bit(EFI_BOOT, &efi.flags);
552 		set_bit(EFI_64BIT, &efi.flags);
553 	}
554 #endif
555 
556 	if (!boot_params.hdr.root_flags)
557 		root_mountflags &= ~MS_RDONLY;
558 }
559 
memblock_x86_reserve_range_setup_data(void)560 static void __init memblock_x86_reserve_range_setup_data(void)
561 {
562 	struct setup_indirect *indirect;
563 	struct setup_data *data;
564 	u64 pa_data, pa_next;
565 	u32 len;
566 
567 	pa_data = boot_params.hdr.setup_data;
568 	while (pa_data) {
569 		data = early_memremap(pa_data, sizeof(*data));
570 		if (!data) {
571 			pr_warn("setup: failed to memremap setup_data entry\n");
572 			return;
573 		}
574 
575 		len = sizeof(*data);
576 		pa_next = data->next;
577 
578 		memblock_reserve_kern(pa_data, sizeof(*data) + data->len);
579 
580 		if (data->type == SETUP_INDIRECT) {
581 			len += data->len;
582 			early_memunmap(data, sizeof(*data));
583 			data = early_memremap(pa_data, len);
584 			if (!data) {
585 				pr_warn("setup: failed to memremap indirect setup_data\n");
586 				return;
587 			}
588 
589 			indirect = (struct setup_indirect *)data->data;
590 
591 			if (indirect->type != SETUP_INDIRECT)
592 				memblock_reserve_kern(indirect->addr, indirect->len);
593 		}
594 
595 		pa_data = pa_next;
596 		early_memunmap(data, len);
597 	}
598 }
599 
arch_reserve_crashkernel(void)600 static void __init arch_reserve_crashkernel(void)
601 {
602 	unsigned long long crash_base, crash_size, low_size = 0;
603 	bool high = false;
604 	int ret;
605 
606 	if (!IS_ENABLED(CONFIG_CRASH_RESERVE))
607 		return;
608 
609 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
610 				&crash_size, &crash_base,
611 				&low_size, &high);
612 	if (ret)
613 		return;
614 
615 	if (xen_pv_domain()) {
616 		pr_info("Ignoring crashkernel for a Xen PV domain\n");
617 		return;
618 	}
619 
620 	reserve_crashkernel_generic(crash_size, crash_base, low_size, high);
621 }
622 
623 static struct resource standard_io_resources[] = {
624 	{ .name = "dma1", .start = 0x00, .end = 0x1f,
625 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
626 	{ .name = "pic1", .start = 0x20, .end = 0x21,
627 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
628 	{ .name = "timer0", .start = 0x40, .end = 0x43,
629 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
630 	{ .name = "timer1", .start = 0x50, .end = 0x53,
631 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
632 	{ .name = "keyboard", .start = 0x60, .end = 0x60,
633 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
634 	{ .name = "keyboard", .start = 0x64, .end = 0x64,
635 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
636 	{ .name = "dma page reg", .start = 0x80, .end = 0x8f,
637 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
638 	{ .name = "pic2", .start = 0xa0, .end = 0xa1,
639 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
640 	{ .name = "dma2", .start = 0xc0, .end = 0xdf,
641 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
642 	{ .name = "fpu", .start = 0xf0, .end = 0xff,
643 		.flags = IORESOURCE_BUSY | IORESOURCE_IO }
644 };
645 
reserve_standard_io_resources(void)646 void __init reserve_standard_io_resources(void)
647 {
648 	int i;
649 
650 	/* request I/O space for devices used on all i[345]86 PCs */
651 	for (i = 0; i < ARRAY_SIZE(standard_io_resources); i++)
652 		request_resource(&ioport_resource, &standard_io_resources[i]);
653 
654 }
655 
setup_kernel_resources(void)656 static void __init setup_kernel_resources(void)
657 {
658 	code_resource.start = __pa_symbol(_text);
659 	code_resource.end = __pa_symbol(_etext)-1;
660 	rodata_resource.start = __pa_symbol(__start_rodata);
661 	rodata_resource.end = __pa_symbol(__end_rodata)-1;
662 	data_resource.start = __pa_symbol(_sdata);
663 	data_resource.end = __pa_symbol(_edata)-1;
664 	bss_resource.start = __pa_symbol(__bss_start);
665 	bss_resource.end = __pa_symbol(__bss_stop)-1;
666 
667 	insert_resource(&iomem_resource, &code_resource);
668 	insert_resource(&iomem_resource, &rodata_resource);
669 	insert_resource(&iomem_resource, &data_resource);
670 	insert_resource(&iomem_resource, &bss_resource);
671 }
672 
snb_gfx_workaround_needed(void)673 static bool __init snb_gfx_workaround_needed(void)
674 {
675 #ifdef CONFIG_PCI
676 	int i;
677 	u16 vendor, devid;
678 	static const __initconst u16 snb_ids[] = {
679 		0x0102,
680 		0x0112,
681 		0x0122,
682 		0x0106,
683 		0x0116,
684 		0x0126,
685 		0x010a,
686 	};
687 
688 	/* Assume no if something weird is going on with PCI */
689 	if (!early_pci_allowed())
690 		return false;
691 
692 	vendor = read_pci_config_16(0, 2, 0, PCI_VENDOR_ID);
693 	if (vendor != 0x8086)
694 		return false;
695 
696 	devid = read_pci_config_16(0, 2, 0, PCI_DEVICE_ID);
697 	for (i = 0; i < ARRAY_SIZE(snb_ids); i++)
698 		if (devid == snb_ids[i])
699 			return true;
700 #endif
701 
702 	return false;
703 }
704 
705 /*
706  * Sandy Bridge graphics has trouble with certain ranges, exclude
707  * them from allocation.
708  */
trim_snb_memory(void)709 static void __init trim_snb_memory(void)
710 {
711 	static const __initconst unsigned long bad_pages[] = {
712 		0x20050000,
713 		0x20110000,
714 		0x20130000,
715 		0x20138000,
716 		0x40004000,
717 	};
718 	int i;
719 
720 	if (!snb_gfx_workaround_needed())
721 		return;
722 
723 	printk(KERN_DEBUG "reserving inaccessible SNB gfx pages\n");
724 
725 	/*
726 	 * SandyBridge integrated graphics devices have a bug that prevents
727 	 * them from accessing certain memory ranges, namely anything below
728 	 * 1M and in the pages listed in bad_pages[] above.
729 	 *
730 	 * To avoid these pages being ever accessed by SNB gfx devices reserve
731 	 * bad_pages that have not already been reserved at boot time.
732 	 * All memory below the 1 MB mark is anyway reserved later during
733 	 * setup_arch(), so there is no need to reserve it here.
734 	 */
735 
736 	for (i = 0; i < ARRAY_SIZE(bad_pages); i++) {
737 		if (memblock_reserve(bad_pages[i], PAGE_SIZE))
738 			printk(KERN_WARNING "failed to reserve 0x%08lx\n",
739 			       bad_pages[i]);
740 	}
741 }
742 
trim_bios_range(void)743 static void __init trim_bios_range(void)
744 {
745 	/*
746 	 * A special case is the first 4Kb of memory;
747 	 * This is a BIOS owned area, not kernel ram, but generally
748 	 * not listed as such in the E820 table.
749 	 *
750 	 * This typically reserves additional memory (64KiB by default)
751 	 * since some BIOSes are known to corrupt low memory.  See the
752 	 * Kconfig help text for X86_RESERVE_LOW.
753 	 */
754 	e820__range_update(0, PAGE_SIZE, E820_TYPE_RAM, E820_TYPE_RESERVED);
755 
756 	/*
757 	 * special case: Some BIOSes report the PC BIOS
758 	 * area (640Kb -> 1Mb) as RAM even though it is not.
759 	 * take them out.
760 	 */
761 	e820__range_remove(BIOS_BEGIN, BIOS_END - BIOS_BEGIN, E820_TYPE_RAM, 1);
762 
763 	e820__update_table(e820_table);
764 }
765 
766 /* called before trim_bios_range() to spare extra sanitize */
e820_add_kernel_range(void)767 static void __init e820_add_kernel_range(void)
768 {
769 	u64 start = __pa_symbol(_text);
770 	u64 size = __pa_symbol(_end) - start;
771 
772 	/*
773 	 * Complain if .text .data and .bss are not marked as E820_TYPE_RAM and
774 	 * attempt to fix it by adding the range. We may have a confused BIOS,
775 	 * or the user may have used memmap=exactmap or memmap=xxM$yyM to
776 	 * exclude kernel range. If we really are running on top non-RAM,
777 	 * we will crash later anyways.
778 	 */
779 	if (e820__mapped_all(start, start + size, E820_TYPE_RAM))
780 		return;
781 
782 	pr_warn(".text .data .bss are not marked as E820_TYPE_RAM!\n");
783 	e820__range_remove(start, size, E820_TYPE_RAM, 0);
784 	e820__range_add(start, size, E820_TYPE_RAM);
785 }
786 
early_reserve_memory(void)787 static void __init early_reserve_memory(void)
788 {
789 	/*
790 	 * Reserve the memory occupied by the kernel between _text and
791 	 * __end_of_kernel_reserve symbols. Any kernel sections after the
792 	 * __end_of_kernel_reserve symbol must be explicitly reserved with a
793 	 * separate memblock_reserve() or they will be discarded.
794 	 */
795 	memblock_reserve_kern(__pa_symbol(_text),
796 			      (unsigned long)__end_of_kernel_reserve - (unsigned long)_text);
797 
798 	/*
799 	 * The first 4Kb of memory is a BIOS owned area, but generally it is
800 	 * not listed as such in the E820 table.
801 	 *
802 	 * Reserve the first 64K of memory since some BIOSes are known to
803 	 * corrupt low memory. After the real mode trampoline is allocated the
804 	 * rest of the memory below 640k is reserved.
805 	 *
806 	 * In addition, make sure page 0 is always reserved because on
807 	 * systems with L1TF its contents can be leaked to user processes.
808 	 */
809 	memblock_reserve(0, SZ_64K);
810 
811 	early_reserve_initrd();
812 
813 	memblock_x86_reserve_range_setup_data();
814 
815 	reserve_bios_regions();
816 	trim_snb_memory();
817 }
818 
819 /*
820  * Dump out kernel offset information on panic.
821  */
822 static int
dump_kernel_offset(struct notifier_block * self,unsigned long v,void * p)823 dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
824 {
825 	if (kaslr_enabled()) {
826 		pr_emerg("Kernel Offset: 0x%lx from 0x%lx (relocation range: 0x%lx-0x%lx)\n",
827 			 kaslr_offset(),
828 			 __START_KERNEL,
829 			 __START_KERNEL_map,
830 			 MODULES_VADDR-1);
831 	} else {
832 		pr_emerg("Kernel Offset: disabled\n");
833 	}
834 
835 	return 0;
836 }
837 
x86_configure_nx(void)838 void x86_configure_nx(void)
839 {
840 	if (boot_cpu_has(X86_FEATURE_NX))
841 		__supported_pte_mask |= _PAGE_NX;
842 	else
843 		__supported_pte_mask &= ~_PAGE_NX;
844 }
845 
x86_report_nx(void)846 static void __init x86_report_nx(void)
847 {
848 	if (!boot_cpu_has(X86_FEATURE_NX)) {
849 		printk(KERN_NOTICE "Notice: NX (Execute Disable) protection "
850 		       "missing in CPU!\n");
851 	} else {
852 #if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
853 		printk(KERN_INFO "NX (Execute Disable) protection: active\n");
854 #else
855 		/* 32bit non-PAE kernel, NX cannot be used */
856 		printk(KERN_NOTICE "Notice: NX (Execute Disable) protection "
857 		       "cannot be enabled: non-PAE kernel!\n");
858 #endif
859 	}
860 }
861 
862 /*
863  * Determine if we were loaded by an EFI loader.  If so, then we have also been
864  * passed the efi memmap, systab, etc., so we should use these data structures
865  * for initialization.  Note, the efi init code path is determined by the
866  * global efi_enabled. This allows the same kernel image to be used on existing
867  * systems (with a traditional BIOS) as well as on EFI systems.
868  */
869 /*
870  * setup_arch - architecture-specific boot-time initializations
871  *
872  * Note: On x86_64, fixmaps are ready for use even before this is called.
873  */
874 
setup_arch(char ** cmdline_p)875 void __init setup_arch(char **cmdline_p)
876 {
877 #ifdef CONFIG_X86_32
878 	memcpy(&boot_cpu_data, &new_cpu_data, sizeof(new_cpu_data));
879 
880 	/*
881 	 * copy kernel address range established so far and switch
882 	 * to the proper swapper page table
883 	 */
884 	clone_pgd_range(swapper_pg_dir     + KERNEL_PGD_BOUNDARY,
885 			initial_page_table + KERNEL_PGD_BOUNDARY,
886 			KERNEL_PGD_PTRS);
887 
888 	load_cr3(swapper_pg_dir);
889 	/*
890 	 * Note: Quark X1000 CPUs advertise PGE incorrectly and require
891 	 * a cr3 based tlb flush, so the following __flush_tlb_all()
892 	 * will not flush anything because the CPU quirk which clears
893 	 * X86_FEATURE_PGE has not been invoked yet. Though due to the
894 	 * load_cr3() above the TLB has been flushed already. The
895 	 * quirk is invoked before subsequent calls to __flush_tlb_all()
896 	 * so proper operation is guaranteed.
897 	 */
898 	__flush_tlb_all();
899 #else
900 	printk(KERN_INFO "Command line: %s\n", boot_command_line);
901 	boot_cpu_data.x86_phys_bits = MAX_PHYSMEM_BITS;
902 #endif
903 
904 #ifdef CONFIG_CMDLINE_BOOL
905 #ifdef CONFIG_CMDLINE_OVERRIDE
906 	strscpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
907 #else
908 	if (builtin_cmdline[0]) {
909 		/* append boot loader cmdline to builtin */
910 		strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);
911 		strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);
912 		strscpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
913 	}
914 #endif
915 	builtin_cmdline_added = true;
916 #endif
917 
918 	strscpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
919 	*cmdline_p = command_line;
920 
921 	/*
922 	 * If we have OLPC OFW, we might end up relocating the fixmap due to
923 	 * reserve_top(), so do this before touching the ioremap area.
924 	 */
925 	olpc_ofw_detect();
926 
927 	idt_setup_early_traps();
928 	early_cpu_init();
929 	jump_label_init();
930 	static_call_init();
931 	early_ioremap_init();
932 
933 	setup_olpc_ofw_pgd();
934 
935 	parse_boot_params();
936 
937 	x86_init.oem.arch_setup();
938 
939 	/*
940 	 * Do some memory reservations *before* memory is added to memblock, so
941 	 * memblock allocations won't overwrite it.
942 	 *
943 	 * After this point, everything still needed from the boot loader or
944 	 * firmware or kernel text should be early reserved or marked not RAM in
945 	 * e820. All other memory is free game.
946 	 *
947 	 * This call needs to happen before e820__memory_setup() which calls the
948 	 * xen_memory_setup() on Xen dom0 which relies on the fact that those
949 	 * early reservations have happened already.
950 	 */
951 	early_reserve_memory();
952 
953 	iomem_resource.end = (1ULL << boot_cpu_data.x86_phys_bits) - 1;
954 	e820__memory_setup();
955 	parse_setup_data();
956 
957 	copy_edd();
958 
959 	setup_initial_init_mm(_text, _etext, _edata, (void *)_brk_end);
960 
961 	/*
962 	 * x86_configure_nx() is called before parse_early_param() to detect
963 	 * whether hardware doesn't support NX (so that the early EHCI debug
964 	 * console setup can safely call set_fixmap()).
965 	 */
966 	x86_configure_nx();
967 
968 	parse_early_param();
969 
970 	if (efi_enabled(EFI_BOOT))
971 		efi_memblock_x86_reserve_range();
972 
973 	x86_report_nx();
974 
975 	apic_setup_apic_calls();
976 
977 	if (acpi_mps_check()) {
978 #ifdef CONFIG_X86_LOCAL_APIC
979 		apic_is_disabled = true;
980 #endif
981 		setup_clear_cpu_cap(X86_FEATURE_APIC);
982 	}
983 
984 	e820__finish_early_params();
985 
986 	if (efi_enabled(EFI_BOOT))
987 		efi_init();
988 
989 	reserve_ibft_region();
990 	x86_init.resources.dmi_setup();
991 
992 	/*
993 	 * VMware detection requires dmi to be available, so this
994 	 * needs to be done after dmi_setup(), for the boot CPU.
995 	 * For some guest types (Xen PV, SEV-SNP, TDX) it is required to be
996 	 * called before cache_bp_init() for setting up MTRR state.
997 	 */
998 	init_hypervisor_platform();
999 
1000 	tsc_early_init();
1001 	x86_init.resources.probe_roms();
1002 
1003 	/*
1004 	 * Add resources for kernel text and data to the iomem_resource.
1005 	 * Do it after parse_early_param, so it can be debugged.
1006 	 */
1007 	setup_kernel_resources();
1008 
1009 	e820_add_kernel_range();
1010 	trim_bios_range();
1011 #ifdef CONFIG_X86_32
1012 	if (ppro_with_ram_bug()) {
1013 		e820__range_update(0x70000000ULL, 0x40000ULL, E820_TYPE_RAM,
1014 				  E820_TYPE_RESERVED);
1015 		e820__update_table(e820_table);
1016 		printk(KERN_INFO "fixed physical RAM map:\n");
1017 		e820__print_table("bad_ppro");
1018 	}
1019 #else
1020 	early_gart_iommu_check();
1021 #endif
1022 
1023 	/*
1024 	 * partially used pages are not usable - thus
1025 	 * we are rounding upwards:
1026 	 */
1027 	max_pfn = e820__end_of_ram_pfn();
1028 
1029 	/* update e820 for memory not covered by WB MTRRs */
1030 	cache_bp_init();
1031 	if (mtrr_trim_uncached_memory(max_pfn))
1032 		max_pfn = e820__end_of_ram_pfn();
1033 
1034 	max_possible_pfn = max_pfn;
1035 
1036 	/*
1037 	 * Define random base addresses for memory sections after max_pfn is
1038 	 * defined and before each memory section base is used.
1039 	 */
1040 	kernel_randomize_memory();
1041 
1042 #ifdef CONFIG_X86_32
1043 	/* max_low_pfn get updated here */
1044 	find_low_pfn_range();
1045 #else
1046 	check_x2apic();
1047 
1048 	/* How many end-of-memory variables you have, grandma! */
1049 	/* need this before calling reserve_initrd */
1050 	if (max_pfn > (1UL<<(32 - PAGE_SHIFT)))
1051 		max_low_pfn = e820__end_of_low_ram_pfn();
1052 	else
1053 		max_low_pfn = max_pfn;
1054 #endif
1055 
1056 	/* Find and reserve MPTABLE area */
1057 	x86_init.mpparse.find_mptable();
1058 
1059 	early_alloc_pgt_buf();
1060 
1061 	/*
1062 	 * Need to conclude brk, before e820__memblock_setup()
1063 	 * it could use memblock_find_in_range, could overlap with
1064 	 * brk area.
1065 	 */
1066 	reserve_brk();
1067 
1068 	cleanup_highmap();
1069 
1070 	e820__memblock_setup();
1071 
1072 	/*
1073 	 * Needs to run after memblock setup because it needs the physical
1074 	 * memory size.
1075 	 */
1076 	mem_encrypt_setup_arch();
1077 	cc_random_init();
1078 
1079 	efi_find_mirror();
1080 	efi_esrt_init();
1081 	efi_mokvar_table_init();
1082 
1083 	/*
1084 	 * The EFI specification says that boot service code won't be
1085 	 * called after ExitBootServices(). This is, in fact, a lie.
1086 	 */
1087 	efi_reserve_boot_services();
1088 
1089 	/* preallocate 4k for mptable mpc */
1090 	e820__memblock_alloc_reserved_mpc_new();
1091 
1092 #ifdef CONFIG_X86_CHECK_BIOS_CORRUPTION
1093 	setup_bios_corruption_check();
1094 #endif
1095 
1096 #ifdef CONFIG_X86_32
1097 	printk(KERN_DEBUG "initial memory mapped: [mem 0x00000000-%#010lx]\n",
1098 			(max_pfn_mapped<<PAGE_SHIFT) - 1);
1099 #endif
1100 
1101 	/*
1102 	 * Find free memory for the real mode trampoline and place it there. If
1103 	 * there is not enough free memory under 1M, on EFI-enabled systems
1104 	 * there will be additional attempt to reclaim the memory for the real
1105 	 * mode trampoline at efi_free_boot_services().
1106 	 *
1107 	 * Unconditionally reserve the entire first 1M of RAM because BIOSes
1108 	 * are known to corrupt low memory and several hundred kilobytes are not
1109 	 * worth complex detection what memory gets clobbered. Windows does the
1110 	 * same thing for very similar reasons.
1111 	 *
1112 	 * Moreover, on machines with SandyBridge graphics or in setups that use
1113 	 * crashkernel the entire 1M is reserved anyway.
1114 	 *
1115 	 * Note the host kernel TDX also requires the first 1MB being reserved.
1116 	 */
1117 	x86_platform.realmode_reserve();
1118 
1119 	init_mem_mapping();
1120 
1121 	/*
1122 	 * init_mem_mapping() relies on the early IDT page fault handling.
1123 	 * Now either enable FRED or install the real page fault handler
1124 	 * for 64-bit in the IDT.
1125 	 */
1126 	cpu_init_replace_early_idt();
1127 
1128 	/*
1129 	 * Update mmu_cr4_features (and, indirectly, trampoline_cr4_features)
1130 	 * with the current CR4 value.  This may not be necessary, but
1131 	 * auditing all the early-boot CR4 manipulation would be needed to
1132 	 * rule it out.
1133 	 *
1134 	 * Mask off features that don't work outside long mode (just
1135 	 * PCIDE for now).
1136 	 */
1137 	mmu_cr4_features = __read_cr4() & ~X86_CR4_PCIDE;
1138 
1139 	memblock_set_current_limit(get_max_mapped());
1140 
1141 	/*
1142 	 * NOTE: On x86-32, only from this point on, fixmaps are ready for use.
1143 	 */
1144 
1145 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
1146 	if (init_ohci1394_dma_early)
1147 		init_ohci1394_dma_on_all_controllers();
1148 #endif
1149 	/* Allocate bigger log buffer */
1150 	setup_log_buf(1);
1151 
1152 	if (efi_enabled(EFI_BOOT)) {
1153 		switch (boot_params.secure_boot) {
1154 		case efi_secureboot_mode_disabled:
1155 			pr_info("Secure boot disabled\n");
1156 			break;
1157 		case efi_secureboot_mode_enabled:
1158 			pr_info("Secure boot enabled\n");
1159 			break;
1160 		default:
1161 			pr_info("Secure boot could not be determined\n");
1162 			break;
1163 		}
1164 	}
1165 
1166 	reserve_initrd();
1167 
1168 	acpi_table_upgrade();
1169 	/* Look for ACPI tables and reserve memory occupied by them. */
1170 	acpi_boot_table_init();
1171 
1172 	vsmp_init();
1173 
1174 	io_delay_init();
1175 
1176 	early_platform_quirks();
1177 
1178 	/* Some platforms need the APIC registered for NUMA configuration */
1179 	early_acpi_boot_init();
1180 	x86_init.mpparse.early_parse_smp_cfg();
1181 
1182 	x86_flattree_get_config();
1183 
1184 	initmem_init();
1185 	dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT);
1186 
1187 	if (boot_cpu_has(X86_FEATURE_GBPAGES)) {
1188 		hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
1189 		hugetlb_bootmem_alloc();
1190 	}
1191 
1192 	/*
1193 	 * Reserve memory for crash kernel after SRAT is parsed so that it
1194 	 * won't consume hotpluggable memory.
1195 	 */
1196 	arch_reserve_crashkernel();
1197 
1198 	if (!early_xdbc_setup_hardware())
1199 		early_xdbc_register_console();
1200 
1201 	x86_init.paging.pagetable_init();
1202 
1203 	kasan_init();
1204 
1205 	/*
1206 	 * Sync back kernel address range.
1207 	 *
1208 	 * FIXME: Can the later sync in setup_cpu_entry_areas() replace
1209 	 * this call?
1210 	 */
1211 	sync_initial_page_table();
1212 
1213 	tboot_probe();
1214 
1215 	map_vsyscall();
1216 
1217 	x86_32_probe_apic();
1218 
1219 	early_quirks();
1220 
1221 	topology_apply_cmdline_limits_early();
1222 
1223 	/*
1224 	 * Parse SMP configuration. Try ACPI first and then the platform
1225 	 * specific parser.
1226 	 */
1227 	acpi_boot_init();
1228 	x86_init.mpparse.parse_smp_cfg();
1229 
1230 	/* Last opportunity to detect and map the local APIC */
1231 	init_apic_mappings();
1232 
1233 	topology_init_possible_cpus();
1234 
1235 	init_cpu_to_node();
1236 	init_gi_nodes();
1237 
1238 	io_apic_init_mappings();
1239 
1240 	x86_init.hyper.guest_late_init();
1241 
1242 	e820__reserve_resources();
1243 	e820__register_nosave_regions(max_pfn);
1244 
1245 	x86_init.resources.reserve_resources();
1246 
1247 	e820__setup_pci_gap();
1248 
1249 #ifdef CONFIG_VT
1250 #if defined(CONFIG_VGA_CONSOLE)
1251 	if (!efi_enabled(EFI_BOOT) || (efi_mem_type(0xa0000) != EFI_CONVENTIONAL_MEMORY))
1252 		vgacon_register_screen(&screen_info);
1253 #endif
1254 #endif
1255 	x86_init.oem.banner();
1256 
1257 	x86_init.timers.wallclock_init();
1258 
1259 	/*
1260 	 * This needs to run before setup_local_APIC() which soft-disables the
1261 	 * local APIC temporarily and that masks the thermal LVT interrupt,
1262 	 * leading to softlockups on machines which have configured SMI
1263 	 * interrupt delivery.
1264 	 */
1265 	therm_lvt_init();
1266 
1267 	mcheck_init();
1268 
1269 	register_refined_jiffies(CLOCK_TICK_RATE);
1270 
1271 #ifdef CONFIG_EFI
1272 	if (efi_enabled(EFI_BOOT))
1273 		efi_apply_memmap_quirks();
1274 #endif
1275 
1276 	unwind_init();
1277 }
1278 
1279 #ifdef CONFIG_X86_32
1280 
1281 static struct resource video_ram_resource = {
1282 	.name	= "Video RAM area",
1283 	.start	= 0xa0000,
1284 	.end	= 0xbffff,
1285 	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM
1286 };
1287 
i386_reserve_resources(void)1288 void __init i386_reserve_resources(void)
1289 {
1290 	request_resource(&iomem_resource, &video_ram_resource);
1291 	reserve_standard_io_resources();
1292 }
1293 
1294 #endif /* CONFIG_X86_32 */
1295 
1296 static struct notifier_block kernel_offset_notifier = {
1297 	.notifier_call = dump_kernel_offset
1298 };
1299 
register_kernel_offset_dumper(void)1300 static int __init register_kernel_offset_dumper(void)
1301 {
1302 	atomic_notifier_chain_register(&panic_notifier_list,
1303 					&kernel_offset_notifier);
1304 	return 0;
1305 }
1306 __initcall(register_kernel_offset_dumper);
1307 
1308 #ifdef CONFIG_HOTPLUG_CPU
arch_cpu_is_hotpluggable(int cpu)1309 bool arch_cpu_is_hotpluggable(int cpu)
1310 {
1311 	return cpu > 0;
1312 }
1313 #endif /* CONFIG_HOTPLUG_CPU */
1314