xref: /linux/arch/x86/kernel/setup.c (revision e991acf1bce7a428794514cbbe216973c9c0a3c8)
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 #if defined(CONFIG_FIRMWARE_EDID)
217 struct edid_info edid_info;
218 EXPORT_SYMBOL_GPL(edid_info);
219 #endif
220 
221 extern int root_mountflags;
222 
223 unsigned long saved_video_mode;
224 
225 #define RAMDISK_IMAGE_START_MASK	0x07FF
226 #define RAMDISK_PROMPT_FLAG		0x8000
227 #define RAMDISK_LOAD_FLAG		0x4000
228 
229 static char __initdata command_line[COMMAND_LINE_SIZE];
230 #ifdef CONFIG_CMDLINE_BOOL
231 char builtin_cmdline[COMMAND_LINE_SIZE] = CONFIG_CMDLINE;
232 bool builtin_cmdline_added __ro_after_init;
233 #endif
234 
235 #if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
236 struct edd edd;
237 #ifdef CONFIG_EDD_MODULE
238 EXPORT_SYMBOL(edd);
239 #endif
240 /**
241  * copy_edd() - Copy the BIOS EDD information
242  *              from boot_params into a safe place.
243  *
244  */
copy_edd(void)245 static inline void __init copy_edd(void)
246 {
247      memcpy(edd.mbr_signature, boot_params.edd_mbr_sig_buffer,
248 	    sizeof(edd.mbr_signature));
249      memcpy(edd.edd_info, boot_params.eddbuf, sizeof(edd.edd_info));
250      edd.mbr_signature_nr = boot_params.edd_mbr_sig_buf_entries;
251      edd.edd_info_nr = boot_params.eddbuf_entries;
252 }
253 #else
copy_edd(void)254 static inline void __init copy_edd(void)
255 {
256 }
257 #endif
258 
extend_brk(size_t size,size_t align)259 void * __init extend_brk(size_t size, size_t align)
260 {
261 	size_t mask = align - 1;
262 	void *ret;
263 
264 	BUG_ON(_brk_start == 0);
265 	BUG_ON(align & mask);
266 
267 	_brk_end = (_brk_end + mask) & ~mask;
268 	BUG_ON((char *)(_brk_end + size) > __brk_limit);
269 
270 	ret = (void *)_brk_end;
271 	_brk_end += size;
272 
273 	memset(ret, 0, size);
274 
275 	return ret;
276 }
277 
278 #ifdef CONFIG_X86_32
cleanup_highmap(void)279 static void __init cleanup_highmap(void)
280 {
281 }
282 #endif
283 
reserve_brk(void)284 static void __init reserve_brk(void)
285 {
286 	if (_brk_end > _brk_start)
287 		memblock_reserve_kern(__pa_symbol(_brk_start),
288 				      _brk_end - _brk_start);
289 
290 	/* Mark brk area as locked down and no longer taking any
291 	   new allocations */
292 	_brk_start = 0;
293 }
294 
295 #ifdef CONFIG_BLK_DEV_INITRD
296 
get_ramdisk_image(void)297 static u64 __init get_ramdisk_image(void)
298 {
299 	u64 ramdisk_image = boot_params.hdr.ramdisk_image;
300 
301 	ramdisk_image |= (u64)boot_params.ext_ramdisk_image << 32;
302 
303 	if (ramdisk_image == 0)
304 		ramdisk_image = phys_initrd_start;
305 
306 	return ramdisk_image;
307 }
get_ramdisk_size(void)308 static u64 __init get_ramdisk_size(void)
309 {
310 	u64 ramdisk_size = boot_params.hdr.ramdisk_size;
311 
312 	ramdisk_size |= (u64)boot_params.ext_ramdisk_size << 32;
313 
314 	if (ramdisk_size == 0)
315 		ramdisk_size = phys_initrd_size;
316 
317 	return ramdisk_size;
318 }
319 
relocate_initrd(void)320 static void __init relocate_initrd(void)
321 {
322 	/* Assume only end is not page aligned */
323 	u64 ramdisk_image = get_ramdisk_image();
324 	u64 ramdisk_size  = get_ramdisk_size();
325 	u64 area_size     = PAGE_ALIGN(ramdisk_size);
326 	int ret = 0;
327 
328 	/* We need to move the initrd down into directly mapped mem */
329 	u64 relocated_ramdisk = memblock_phys_alloc_range(area_size, PAGE_SIZE, 0,
330 						      PFN_PHYS(max_pfn_mapped));
331 	if (!relocated_ramdisk)
332 		panic("Cannot find place for new RAMDISK of size %lld\n",
333 		      ramdisk_size);
334 
335 	initrd_start = relocated_ramdisk + PAGE_OFFSET;
336 	initrd_end   = initrd_start + ramdisk_size;
337 	printk(KERN_INFO "Allocated new RAMDISK: [mem %#010llx-%#010llx]\n",
338 	       relocated_ramdisk, relocated_ramdisk + ramdisk_size - 1);
339 
340 	ret = copy_from_early_mem((void *)initrd_start, ramdisk_image, ramdisk_size);
341 	if (ret)
342 		panic("Copy RAMDISK failed\n");
343 
344 	printk(KERN_INFO "Move RAMDISK from [mem %#010llx-%#010llx] to"
345 		" [mem %#010llx-%#010llx]\n",
346 		ramdisk_image, ramdisk_image + ramdisk_size - 1,
347 		relocated_ramdisk, relocated_ramdisk + ramdisk_size - 1);
348 }
349 
early_reserve_initrd(void)350 static void __init early_reserve_initrd(void)
351 {
352 	/* Assume only end is not page aligned */
353 	u64 ramdisk_image = get_ramdisk_image();
354 	u64 ramdisk_size  = get_ramdisk_size();
355 	u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
356 
357 	if (!boot_params.hdr.type_of_loader ||
358 	    !ramdisk_image || !ramdisk_size)
359 		return;		/* No initrd provided by bootloader */
360 
361 	memblock_reserve_kern(ramdisk_image, ramdisk_end - ramdisk_image);
362 }
363 
reserve_initrd(void)364 static void __init reserve_initrd(void)
365 {
366 	/* Assume only end is not page aligned */
367 	u64 ramdisk_image = get_ramdisk_image();
368 	u64 ramdisk_size  = get_ramdisk_size();
369 	u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
370 
371 	if (!boot_params.hdr.type_of_loader ||
372 	    !ramdisk_image || !ramdisk_size)
373 		return;		/* No initrd provided by bootloader */
374 
375 	initrd_start = 0;
376 
377 	printk(KERN_INFO "RAMDISK: [mem %#010llx-%#010llx]\n", ramdisk_image,
378 			ramdisk_end - 1);
379 
380 	if (pfn_range_is_mapped(PFN_DOWN(ramdisk_image),
381 				PFN_DOWN(ramdisk_end))) {
382 		/* All are mapped, easy case */
383 		initrd_start = ramdisk_image + PAGE_OFFSET;
384 		initrd_end = initrd_start + ramdisk_size;
385 		return;
386 	}
387 
388 	relocate_initrd();
389 
390 	memblock_phys_free(ramdisk_image, ramdisk_end - ramdisk_image);
391 }
392 
393 #else
early_reserve_initrd(void)394 static void __init early_reserve_initrd(void)
395 {
396 }
reserve_initrd(void)397 static void __init reserve_initrd(void)
398 {
399 }
400 #endif /* CONFIG_BLK_DEV_INITRD */
401 
add_early_ima_buffer(u64 phys_addr)402 static void __init add_early_ima_buffer(u64 phys_addr)
403 {
404 #ifdef CONFIG_IMA
405 	struct ima_setup_data *data;
406 
407 	data = early_memremap(phys_addr + sizeof(struct setup_data), sizeof(*data));
408 	if (!data) {
409 		pr_warn("setup: failed to memremap ima_setup_data entry\n");
410 		return;
411 	}
412 
413 	if (data->size) {
414 		memblock_reserve_kern(data->addr, data->size);
415 		ima_kexec_buffer_phys = data->addr;
416 		ima_kexec_buffer_size = data->size;
417 	}
418 
419 	early_memunmap(data, sizeof(*data));
420 #else
421 	pr_warn("Passed IMA kexec data, but CONFIG_IMA not set. Ignoring.\n");
422 #endif
423 }
424 
425 #if defined(CONFIG_HAVE_IMA_KEXEC) && !defined(CONFIG_OF_FLATTREE)
ima_free_kexec_buffer(void)426 int __init ima_free_kexec_buffer(void)
427 {
428 	if (!ima_kexec_buffer_size)
429 		return -ENOENT;
430 
431 	memblock_free_late(ima_kexec_buffer_phys,
432 			   ima_kexec_buffer_size);
433 
434 	ima_kexec_buffer_phys = 0;
435 	ima_kexec_buffer_size = 0;
436 
437 	return 0;
438 }
439 
ima_get_kexec_buffer(void ** addr,size_t * size)440 int __init ima_get_kexec_buffer(void **addr, size_t *size)
441 {
442 	if (!ima_kexec_buffer_size)
443 		return -ENOENT;
444 
445 	*addr = __va(ima_kexec_buffer_phys);
446 	*size = ima_kexec_buffer_size;
447 
448 	return 0;
449 }
450 #endif
451 
add_kho(u64 phys_addr,u32 data_len)452 static void __init add_kho(u64 phys_addr, u32 data_len)
453 {
454 	struct kho_data *kho;
455 	u64 addr = phys_addr + sizeof(struct setup_data);
456 	u64 size = data_len - sizeof(struct setup_data);
457 
458 	if (!IS_ENABLED(CONFIG_KEXEC_HANDOVER)) {
459 		pr_warn("Passed KHO data, but CONFIG_KEXEC_HANDOVER not set. Ignoring.\n");
460 		return;
461 	}
462 
463 	kho = early_memremap(addr, size);
464 	if (!kho) {
465 		pr_warn("setup: failed to memremap kho data (0x%llx, 0x%llx)\n",
466 			addr, size);
467 		return;
468 	}
469 
470 	kho_populate(kho->fdt_addr, kho->fdt_size, kho->scratch_addr, kho->scratch_size);
471 
472 	early_memunmap(kho, size);
473 }
474 
parse_setup_data(void)475 static void __init parse_setup_data(void)
476 {
477 	struct setup_data *data;
478 	u64 pa_data, pa_next;
479 
480 	pa_data = boot_params.hdr.setup_data;
481 	while (pa_data) {
482 		u32 data_len, data_type;
483 
484 		data = early_memremap(pa_data, sizeof(*data));
485 		data_len = data->len + sizeof(struct setup_data);
486 		data_type = data->type;
487 		pa_next = data->next;
488 		early_memunmap(data, sizeof(*data));
489 
490 		switch (data_type) {
491 		case SETUP_E820_EXT:
492 			e820__memory_setup_extended(pa_data, data_len);
493 			break;
494 		case SETUP_DTB:
495 			add_dtb(pa_data);
496 			break;
497 		case SETUP_EFI:
498 			parse_efi_setup(pa_data, data_len);
499 			break;
500 		case SETUP_IMA:
501 			add_early_ima_buffer(pa_data);
502 			break;
503 		case SETUP_KEXEC_KHO:
504 			add_kho(pa_data, data_len);
505 			break;
506 		case SETUP_RNG_SEED:
507 			data = early_memremap(pa_data, data_len);
508 			add_bootloader_randomness(data->data, data->len);
509 			/* Zero seed for forward secrecy. */
510 			memzero_explicit(data->data, data->len);
511 			/* Zero length in case we find ourselves back here by accident. */
512 			memzero_explicit(&data->len, sizeof(data->len));
513 			early_memunmap(data, data_len);
514 			break;
515 		default:
516 			break;
517 		}
518 		pa_data = pa_next;
519 	}
520 }
521 
522 /*
523  * Translate the fields of 'struct boot_param' into global variables
524  * representing these parameters.
525  */
parse_boot_params(void)526 static void __init parse_boot_params(void)
527 {
528 	ROOT_DEV = old_decode_dev(boot_params.hdr.root_dev);
529 	screen_info = boot_params.screen_info;
530 #if defined(CONFIG_FIRMWARE_EDID)
531 	edid_info = boot_params.edid_info;
532 #endif
533 #ifdef CONFIG_X86_32
534 	apm_info.bios = boot_params.apm_bios_info;
535 	ist_info = boot_params.ist_info;
536 #endif
537 	saved_video_mode = boot_params.hdr.vid_mode;
538 	bootloader_type = boot_params.hdr.type_of_loader;
539 	if ((bootloader_type >> 4) == 0xe) {
540 		bootloader_type &= 0xf;
541 		bootloader_type |= (boot_params.hdr.ext_loader_type+0x10) << 4;
542 	}
543 	bootloader_version  = bootloader_type & 0xf;
544 	bootloader_version |= boot_params.hdr.ext_loader_ver << 4;
545 
546 #ifdef CONFIG_BLK_DEV_RAM
547 	rd_image_start = boot_params.hdr.ram_size & RAMDISK_IMAGE_START_MASK;
548 #endif
549 #ifdef CONFIG_EFI
550 	if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
551 		     EFI32_LOADER_SIGNATURE, 4)) {
552 		set_bit(EFI_BOOT, &efi.flags);
553 	} else if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
554 		     EFI64_LOADER_SIGNATURE, 4)) {
555 		set_bit(EFI_BOOT, &efi.flags);
556 		set_bit(EFI_64BIT, &efi.flags);
557 	}
558 #endif
559 
560 	if (!boot_params.hdr.root_flags)
561 		root_mountflags &= ~MS_RDONLY;
562 }
563 
memblock_x86_reserve_range_setup_data(void)564 static void __init memblock_x86_reserve_range_setup_data(void)
565 {
566 	struct setup_indirect *indirect;
567 	struct setup_data *data;
568 	u64 pa_data, pa_next;
569 	u32 len;
570 
571 	pa_data = boot_params.hdr.setup_data;
572 	while (pa_data) {
573 		data = early_memremap(pa_data, sizeof(*data));
574 		if (!data) {
575 			pr_warn("setup: failed to memremap setup_data entry\n");
576 			return;
577 		}
578 
579 		len = sizeof(*data);
580 		pa_next = data->next;
581 
582 		memblock_reserve_kern(pa_data, sizeof(*data) + data->len);
583 
584 		if (data->type == SETUP_INDIRECT) {
585 			len += data->len;
586 			early_memunmap(data, sizeof(*data));
587 			data = early_memremap(pa_data, len);
588 			if (!data) {
589 				pr_warn("setup: failed to memremap indirect setup_data\n");
590 				return;
591 			}
592 
593 			indirect = (struct setup_indirect *)data->data;
594 
595 			if (indirect->type != SETUP_INDIRECT)
596 				memblock_reserve_kern(indirect->addr, indirect->len);
597 		}
598 
599 		pa_data = pa_next;
600 		early_memunmap(data, len);
601 	}
602 }
603 
arch_reserve_crashkernel(void)604 static void __init arch_reserve_crashkernel(void)
605 {
606 	unsigned long long crash_base, crash_size, low_size = 0, cma_size = 0;
607 	bool high = false;
608 	int ret;
609 
610 	if (!IS_ENABLED(CONFIG_CRASH_RESERVE))
611 		return;
612 
613 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
614 				&crash_size, &crash_base,
615 				&low_size, &cma_size, &high);
616 	if (ret)
617 		return;
618 
619 	if (xen_pv_domain()) {
620 		pr_info("Ignoring crashkernel for a Xen PV domain\n");
621 		return;
622 	}
623 
624 	reserve_crashkernel_generic(crash_size, crash_base, low_size, high);
625 	reserve_crashkernel_cma(cma_size);
626 }
627 
628 static struct resource standard_io_resources[] = {
629 	{ .name = "dma1", .start = 0x00, .end = 0x1f,
630 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
631 	{ .name = "pic1", .start = 0x20, .end = 0x21,
632 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
633 	{ .name = "timer0", .start = 0x40, .end = 0x43,
634 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
635 	{ .name = "timer1", .start = 0x50, .end = 0x53,
636 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
637 	{ .name = "keyboard", .start = 0x60, .end = 0x60,
638 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
639 	{ .name = "keyboard", .start = 0x64, .end = 0x64,
640 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
641 	{ .name = "dma page reg", .start = 0x80, .end = 0x8f,
642 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
643 	{ .name = "pic2", .start = 0xa0, .end = 0xa1,
644 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
645 	{ .name = "dma2", .start = 0xc0, .end = 0xdf,
646 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
647 	{ .name = "fpu", .start = 0xf0, .end = 0xff,
648 		.flags = IORESOURCE_BUSY | IORESOURCE_IO }
649 };
650 
reserve_standard_io_resources(void)651 void __init reserve_standard_io_resources(void)
652 {
653 	int i;
654 
655 	/* request I/O space for devices used on all i[345]86 PCs */
656 	for (i = 0; i < ARRAY_SIZE(standard_io_resources); i++)
657 		request_resource(&ioport_resource, &standard_io_resources[i]);
658 
659 }
660 
setup_kernel_resources(void)661 static void __init setup_kernel_resources(void)
662 {
663 	code_resource.start = __pa_symbol(_text);
664 	code_resource.end = __pa_symbol(_etext)-1;
665 	rodata_resource.start = __pa_symbol(__start_rodata);
666 	rodata_resource.end = __pa_symbol(__end_rodata)-1;
667 	data_resource.start = __pa_symbol(_sdata);
668 	data_resource.end = __pa_symbol(_edata)-1;
669 	bss_resource.start = __pa_symbol(__bss_start);
670 	bss_resource.end = __pa_symbol(__bss_stop)-1;
671 
672 	insert_resource(&iomem_resource, &code_resource);
673 	insert_resource(&iomem_resource, &rodata_resource);
674 	insert_resource(&iomem_resource, &data_resource);
675 	insert_resource(&iomem_resource, &bss_resource);
676 }
677 
snb_gfx_workaround_needed(void)678 static bool __init snb_gfx_workaround_needed(void)
679 {
680 #ifdef CONFIG_PCI
681 	int i;
682 	u16 vendor, devid;
683 	static const __initconst u16 snb_ids[] = {
684 		0x0102,
685 		0x0112,
686 		0x0122,
687 		0x0106,
688 		0x0116,
689 		0x0126,
690 		0x010a,
691 	};
692 
693 	/* Assume no if something weird is going on with PCI */
694 	if (!early_pci_allowed())
695 		return false;
696 
697 	vendor = read_pci_config_16(0, 2, 0, PCI_VENDOR_ID);
698 	if (vendor != 0x8086)
699 		return false;
700 
701 	devid = read_pci_config_16(0, 2, 0, PCI_DEVICE_ID);
702 	for (i = 0; i < ARRAY_SIZE(snb_ids); i++)
703 		if (devid == snb_ids[i])
704 			return true;
705 #endif
706 
707 	return false;
708 }
709 
710 /*
711  * Sandy Bridge graphics has trouble with certain ranges, exclude
712  * them from allocation.
713  */
trim_snb_memory(void)714 static void __init trim_snb_memory(void)
715 {
716 	static const __initconst unsigned long bad_pages[] = {
717 		0x20050000,
718 		0x20110000,
719 		0x20130000,
720 		0x20138000,
721 		0x40004000,
722 	};
723 	int i;
724 
725 	if (!snb_gfx_workaround_needed())
726 		return;
727 
728 	printk(KERN_DEBUG "reserving inaccessible SNB gfx pages\n");
729 
730 	/*
731 	 * SandyBridge integrated graphics devices have a bug that prevents
732 	 * them from accessing certain memory ranges, namely anything below
733 	 * 1M and in the pages listed in bad_pages[] above.
734 	 *
735 	 * To avoid these pages being ever accessed by SNB gfx devices reserve
736 	 * bad_pages that have not already been reserved at boot time.
737 	 * All memory below the 1 MB mark is anyway reserved later during
738 	 * setup_arch(), so there is no need to reserve it here.
739 	 */
740 
741 	for (i = 0; i < ARRAY_SIZE(bad_pages); i++) {
742 		if (memblock_reserve(bad_pages[i], PAGE_SIZE))
743 			printk(KERN_WARNING "failed to reserve 0x%08lx\n",
744 			       bad_pages[i]);
745 	}
746 }
747 
trim_bios_range(void)748 static void __init trim_bios_range(void)
749 {
750 	/*
751 	 * A special case is the first 4Kb of memory;
752 	 * This is a BIOS owned area, not kernel ram, but generally
753 	 * not listed as such in the E820 table.
754 	 *
755 	 * This typically reserves additional memory (64KiB by default)
756 	 * since some BIOSes are known to corrupt low memory.  See the
757 	 * Kconfig help text for X86_RESERVE_LOW.
758 	 */
759 	e820__range_update(0, PAGE_SIZE, E820_TYPE_RAM, E820_TYPE_RESERVED);
760 
761 	/*
762 	 * special case: Some BIOSes report the PC BIOS
763 	 * area (640Kb -> 1Mb) as RAM even though it is not.
764 	 * take them out.
765 	 */
766 	e820__range_remove(BIOS_BEGIN, BIOS_END - BIOS_BEGIN, E820_TYPE_RAM, 1);
767 
768 	e820__update_table(e820_table);
769 }
770 
771 /* called before trim_bios_range() to spare extra sanitize */
e820_add_kernel_range(void)772 static void __init e820_add_kernel_range(void)
773 {
774 	u64 start = __pa_symbol(_text);
775 	u64 size = __pa_symbol(_end) - start;
776 
777 	/*
778 	 * Complain if .text .data and .bss are not marked as E820_TYPE_RAM and
779 	 * attempt to fix it by adding the range. We may have a confused BIOS,
780 	 * or the user may have used memmap=exactmap or memmap=xxM$yyM to
781 	 * exclude kernel range. If we really are running on top non-RAM,
782 	 * we will crash later anyways.
783 	 */
784 	if (e820__mapped_all(start, start + size, E820_TYPE_RAM))
785 		return;
786 
787 	pr_warn(".text .data .bss are not marked as E820_TYPE_RAM!\n");
788 	e820__range_remove(start, size, E820_TYPE_RAM, 0);
789 	e820__range_add(start, size, E820_TYPE_RAM);
790 }
791 
early_reserve_memory(void)792 static void __init early_reserve_memory(void)
793 {
794 	/*
795 	 * Reserve the memory occupied by the kernel between _text and
796 	 * __end_of_kernel_reserve symbols. Any kernel sections after the
797 	 * __end_of_kernel_reserve symbol must be explicitly reserved with a
798 	 * separate memblock_reserve() or they will be discarded.
799 	 */
800 	memblock_reserve_kern(__pa_symbol(_text),
801 			      (unsigned long)__end_of_kernel_reserve - (unsigned long)_text);
802 
803 	/*
804 	 * The first 4Kb of memory is a BIOS owned area, but generally it is
805 	 * not listed as such in the E820 table.
806 	 *
807 	 * Reserve the first 64K of memory since some BIOSes are known to
808 	 * corrupt low memory. After the real mode trampoline is allocated the
809 	 * rest of the memory below 640k is reserved.
810 	 *
811 	 * In addition, make sure page 0 is always reserved because on
812 	 * systems with L1TF its contents can be leaked to user processes.
813 	 */
814 	memblock_reserve(0, SZ_64K);
815 
816 	early_reserve_initrd();
817 
818 	memblock_x86_reserve_range_setup_data();
819 
820 	reserve_bios_regions();
821 	trim_snb_memory();
822 }
823 
824 /*
825  * Dump out kernel offset information on panic.
826  */
827 static int
dump_kernel_offset(struct notifier_block * self,unsigned long v,void * p)828 dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
829 {
830 	if (kaslr_enabled()) {
831 		pr_emerg("Kernel Offset: 0x%lx from 0x%lx (relocation range: 0x%lx-0x%lx)\n",
832 			 kaslr_offset(),
833 			 __START_KERNEL,
834 			 __START_KERNEL_map,
835 			 MODULES_VADDR-1);
836 	} else {
837 		pr_emerg("Kernel Offset: disabled\n");
838 	}
839 
840 	return 0;
841 }
842 
x86_configure_nx(void)843 void x86_configure_nx(void)
844 {
845 	if (boot_cpu_has(X86_FEATURE_NX))
846 		__supported_pte_mask |= _PAGE_NX;
847 	else
848 		__supported_pte_mask &= ~_PAGE_NX;
849 }
850 
x86_report_nx(void)851 static void __init x86_report_nx(void)
852 {
853 	if (!boot_cpu_has(X86_FEATURE_NX)) {
854 		printk(KERN_NOTICE "Notice: NX (Execute Disable) protection "
855 		       "missing in CPU!\n");
856 	} else {
857 #if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
858 		printk(KERN_INFO "NX (Execute Disable) protection: active\n");
859 #else
860 		/* 32bit non-PAE kernel, NX cannot be used */
861 		printk(KERN_NOTICE "Notice: NX (Execute Disable) protection "
862 		       "cannot be enabled: non-PAE kernel!\n");
863 #endif
864 	}
865 }
866 
867 /*
868  * Determine if we were loaded by an EFI loader.  If so, then we have also been
869  * passed the efi memmap, systab, etc., so we should use these data structures
870  * for initialization.  Note, the efi init code path is determined by the
871  * global efi_enabled. This allows the same kernel image to be used on existing
872  * systems (with a traditional BIOS) as well as on EFI systems.
873  */
874 /*
875  * setup_arch - architecture-specific boot-time initializations
876  *
877  * Note: On x86_64, fixmaps are ready for use even before this is called.
878  */
879 
setup_arch(char ** cmdline_p)880 void __init setup_arch(char **cmdline_p)
881 {
882 #ifdef CONFIG_X86_32
883 	memcpy(&boot_cpu_data, &new_cpu_data, sizeof(new_cpu_data));
884 
885 	/*
886 	 * copy kernel address range established so far and switch
887 	 * to the proper swapper page table
888 	 */
889 	clone_pgd_range(swapper_pg_dir     + KERNEL_PGD_BOUNDARY,
890 			initial_page_table + KERNEL_PGD_BOUNDARY,
891 			KERNEL_PGD_PTRS);
892 
893 	load_cr3(swapper_pg_dir);
894 	/*
895 	 * Note: Quark X1000 CPUs advertise PGE incorrectly and require
896 	 * a cr3 based tlb flush, so the following __flush_tlb_all()
897 	 * will not flush anything because the CPU quirk which clears
898 	 * X86_FEATURE_PGE has not been invoked yet. Though due to the
899 	 * load_cr3() above the TLB has been flushed already. The
900 	 * quirk is invoked before subsequent calls to __flush_tlb_all()
901 	 * so proper operation is guaranteed.
902 	 */
903 	__flush_tlb_all();
904 #else
905 	printk(KERN_INFO "Command line: %s\n", boot_command_line);
906 	boot_cpu_data.x86_phys_bits = MAX_PHYSMEM_BITS;
907 #endif
908 
909 #ifdef CONFIG_CMDLINE_BOOL
910 #ifdef CONFIG_CMDLINE_OVERRIDE
911 	strscpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
912 #else
913 	if (builtin_cmdline[0]) {
914 		/* append boot loader cmdline to builtin */
915 		strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);
916 		strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);
917 		strscpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
918 	}
919 #endif
920 	builtin_cmdline_added = true;
921 #endif
922 
923 	strscpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
924 	*cmdline_p = command_line;
925 
926 	/*
927 	 * If we have OLPC OFW, we might end up relocating the fixmap due to
928 	 * reserve_top(), so do this before touching the ioremap area.
929 	 */
930 	olpc_ofw_detect();
931 
932 	idt_setup_early_traps();
933 	early_cpu_init();
934 	jump_label_init();
935 	static_call_init();
936 	early_ioremap_init();
937 
938 	setup_olpc_ofw_pgd();
939 
940 	parse_boot_params();
941 
942 	x86_init.oem.arch_setup();
943 
944 	/*
945 	 * Do some memory reservations *before* memory is added to memblock, so
946 	 * memblock allocations won't overwrite it.
947 	 *
948 	 * After this point, everything still needed from the boot loader or
949 	 * firmware or kernel text should be early reserved or marked not RAM in
950 	 * e820. All other memory is free game.
951 	 *
952 	 * This call needs to happen before e820__memory_setup() which calls the
953 	 * xen_memory_setup() on Xen dom0 which relies on the fact that those
954 	 * early reservations have happened already.
955 	 */
956 	early_reserve_memory();
957 
958 	iomem_resource.end = (1ULL << boot_cpu_data.x86_phys_bits) - 1;
959 	e820__memory_setup();
960 	parse_setup_data();
961 
962 	copy_edd();
963 
964 	setup_initial_init_mm(_text, _etext, _edata, (void *)_brk_end);
965 
966 	/*
967 	 * x86_configure_nx() is called before parse_early_param() to detect
968 	 * whether hardware doesn't support NX (so that the early EHCI debug
969 	 * console setup can safely call set_fixmap()).
970 	 */
971 	x86_configure_nx();
972 
973 	parse_early_param();
974 
975 	if (efi_enabled(EFI_BOOT))
976 		efi_memblock_x86_reserve_range();
977 
978 	x86_report_nx();
979 
980 	apic_setup_apic_calls();
981 
982 	if (acpi_mps_check()) {
983 #ifdef CONFIG_X86_LOCAL_APIC
984 		apic_is_disabled = true;
985 #endif
986 		setup_clear_cpu_cap(X86_FEATURE_APIC);
987 	}
988 
989 	e820__finish_early_params();
990 
991 	if (efi_enabled(EFI_BOOT))
992 		efi_init();
993 
994 	reserve_ibft_region();
995 	x86_init.resources.dmi_setup();
996 
997 	/*
998 	 * VMware detection requires dmi to be available, so this
999 	 * needs to be done after dmi_setup(), for the boot CPU.
1000 	 * For some guest types (Xen PV, SEV-SNP, TDX) it is required to be
1001 	 * called before cache_bp_init() for setting up MTRR state.
1002 	 */
1003 	init_hypervisor_platform();
1004 
1005 	tsc_early_init();
1006 	x86_init.resources.probe_roms();
1007 
1008 	/*
1009 	 * Add resources for kernel text and data to the iomem_resource.
1010 	 * Do it after parse_early_param, so it can be debugged.
1011 	 */
1012 	setup_kernel_resources();
1013 
1014 	e820_add_kernel_range();
1015 	trim_bios_range();
1016 #ifdef CONFIG_X86_32
1017 	if (ppro_with_ram_bug()) {
1018 		e820__range_update(0x70000000ULL, 0x40000ULL, E820_TYPE_RAM,
1019 				  E820_TYPE_RESERVED);
1020 		e820__update_table(e820_table);
1021 		printk(KERN_INFO "fixed physical RAM map:\n");
1022 		e820__print_table("bad_ppro");
1023 	}
1024 #else
1025 	early_gart_iommu_check();
1026 #endif
1027 
1028 	/*
1029 	 * partially used pages are not usable - thus
1030 	 * we are rounding upwards:
1031 	 */
1032 	max_pfn = e820__end_of_ram_pfn();
1033 
1034 	/* update e820 for memory not covered by WB MTRRs */
1035 	cache_bp_init();
1036 	if (mtrr_trim_uncached_memory(max_pfn))
1037 		max_pfn = e820__end_of_ram_pfn();
1038 
1039 	max_possible_pfn = max_pfn;
1040 
1041 	/*
1042 	 * Define random base addresses for memory sections after max_pfn is
1043 	 * defined and before each memory section base is used.
1044 	 */
1045 	kernel_randomize_memory();
1046 
1047 #ifdef CONFIG_X86_32
1048 	/* max_low_pfn get updated here */
1049 	find_low_pfn_range();
1050 #else
1051 	check_x2apic();
1052 
1053 	/* How many end-of-memory variables you have, grandma! */
1054 	/* need this before calling reserve_initrd */
1055 	if (max_pfn > (1UL<<(32 - PAGE_SHIFT)))
1056 		max_low_pfn = e820__end_of_low_ram_pfn();
1057 	else
1058 		max_low_pfn = max_pfn;
1059 #endif
1060 
1061 	/* Find and reserve MPTABLE area */
1062 	x86_init.mpparse.find_mptable();
1063 
1064 	early_alloc_pgt_buf();
1065 
1066 	/*
1067 	 * Need to conclude brk, before e820__memblock_setup()
1068 	 * it could use memblock_find_in_range, could overlap with
1069 	 * brk area.
1070 	 */
1071 	reserve_brk();
1072 
1073 	cleanup_highmap();
1074 
1075 	e820__memblock_setup();
1076 
1077 	/*
1078 	 * Needs to run after memblock setup because it needs the physical
1079 	 * memory size.
1080 	 */
1081 	mem_encrypt_setup_arch();
1082 	cc_random_init();
1083 
1084 	efi_find_mirror();
1085 	efi_esrt_init();
1086 	efi_mokvar_table_init();
1087 
1088 	/*
1089 	 * The EFI specification says that boot service code won't be
1090 	 * called after ExitBootServices(). This is, in fact, a lie.
1091 	 */
1092 	efi_reserve_boot_services();
1093 
1094 	/* preallocate 4k for mptable mpc */
1095 	e820__memblock_alloc_reserved_mpc_new();
1096 
1097 #ifdef CONFIG_X86_CHECK_BIOS_CORRUPTION
1098 	setup_bios_corruption_check();
1099 #endif
1100 
1101 #ifdef CONFIG_X86_32
1102 	printk(KERN_DEBUG "initial memory mapped: [mem 0x00000000-%#010lx]\n",
1103 			(max_pfn_mapped<<PAGE_SHIFT) - 1);
1104 #endif
1105 
1106 	/*
1107 	 * Find free memory for the real mode trampoline and place it there. If
1108 	 * there is not enough free memory under 1M, on EFI-enabled systems
1109 	 * there will be additional attempt to reclaim the memory for the real
1110 	 * mode trampoline at efi_free_boot_services().
1111 	 *
1112 	 * Unconditionally reserve the entire first 1M of RAM because BIOSes
1113 	 * are known to corrupt low memory and several hundred kilobytes are not
1114 	 * worth complex detection what memory gets clobbered. Windows does the
1115 	 * same thing for very similar reasons.
1116 	 *
1117 	 * Moreover, on machines with SandyBridge graphics or in setups that use
1118 	 * crashkernel the entire 1M is reserved anyway.
1119 	 *
1120 	 * Note the host kernel TDX also requires the first 1MB being reserved.
1121 	 */
1122 	x86_platform.realmode_reserve();
1123 
1124 	init_mem_mapping();
1125 
1126 	/*
1127 	 * init_mem_mapping() relies on the early IDT page fault handling.
1128 	 * Now either enable FRED or install the real page fault handler
1129 	 * for 64-bit in the IDT.
1130 	 */
1131 	cpu_init_replace_early_idt();
1132 
1133 	/*
1134 	 * Update mmu_cr4_features (and, indirectly, trampoline_cr4_features)
1135 	 * with the current CR4 value.  This may not be necessary, but
1136 	 * auditing all the early-boot CR4 manipulation would be needed to
1137 	 * rule it out.
1138 	 *
1139 	 * Mask off features that don't work outside long mode (just
1140 	 * PCIDE for now).
1141 	 */
1142 	mmu_cr4_features = __read_cr4() & ~X86_CR4_PCIDE;
1143 
1144 	memblock_set_current_limit(get_max_mapped());
1145 
1146 	/*
1147 	 * NOTE: On x86-32, only from this point on, fixmaps are ready for use.
1148 	 */
1149 
1150 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
1151 	if (init_ohci1394_dma_early)
1152 		init_ohci1394_dma_on_all_controllers();
1153 #endif
1154 	/* Allocate bigger log buffer */
1155 	setup_log_buf(1);
1156 
1157 	if (efi_enabled(EFI_BOOT)) {
1158 		switch (boot_params.secure_boot) {
1159 		case efi_secureboot_mode_disabled:
1160 			pr_info("Secure boot disabled\n");
1161 			break;
1162 		case efi_secureboot_mode_enabled:
1163 			pr_info("Secure boot enabled\n");
1164 			break;
1165 		default:
1166 			pr_info("Secure boot could not be determined\n");
1167 			break;
1168 		}
1169 	}
1170 
1171 	reserve_initrd();
1172 
1173 	acpi_table_upgrade();
1174 	/* Look for ACPI tables and reserve memory occupied by them. */
1175 	acpi_boot_table_init();
1176 
1177 	vsmp_init();
1178 
1179 	io_delay_init();
1180 
1181 	early_platform_quirks();
1182 
1183 	/* Some platforms need the APIC registered for NUMA configuration */
1184 	early_acpi_boot_init();
1185 	x86_init.mpparse.early_parse_smp_cfg();
1186 
1187 	x86_flattree_get_config();
1188 
1189 	initmem_init();
1190 	dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT);
1191 
1192 	if (boot_cpu_has(X86_FEATURE_GBPAGES)) {
1193 		hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
1194 		hugetlb_bootmem_alloc();
1195 	}
1196 
1197 	/*
1198 	 * Reserve memory for crash kernel after SRAT is parsed so that it
1199 	 * won't consume hotpluggable memory.
1200 	 */
1201 	arch_reserve_crashkernel();
1202 
1203 	if (!early_xdbc_setup_hardware())
1204 		early_xdbc_register_console();
1205 
1206 	x86_init.paging.pagetable_init();
1207 
1208 	kasan_init();
1209 
1210 	/*
1211 	 * Sync back kernel address range.
1212 	 *
1213 	 * FIXME: Can the later sync in setup_cpu_entry_areas() replace
1214 	 * this call?
1215 	 */
1216 	sync_initial_page_table();
1217 
1218 	tboot_probe();
1219 
1220 	map_vsyscall();
1221 
1222 	x86_32_probe_apic();
1223 
1224 	early_quirks();
1225 
1226 	topology_apply_cmdline_limits_early();
1227 
1228 	/*
1229 	 * Parse SMP configuration. Try ACPI first and then the platform
1230 	 * specific parser.
1231 	 */
1232 	acpi_boot_init();
1233 	x86_init.mpparse.parse_smp_cfg();
1234 
1235 	/* Last opportunity to detect and map the local APIC */
1236 	init_apic_mappings();
1237 
1238 	topology_init_possible_cpus();
1239 
1240 	init_cpu_to_node();
1241 	init_gi_nodes();
1242 
1243 	io_apic_init_mappings();
1244 
1245 	x86_init.hyper.guest_late_init();
1246 
1247 	e820__reserve_resources();
1248 	e820__register_nosave_regions(max_pfn);
1249 
1250 	x86_init.resources.reserve_resources();
1251 
1252 	e820__setup_pci_gap();
1253 
1254 #ifdef CONFIG_VT
1255 #if defined(CONFIG_VGA_CONSOLE)
1256 	if (!efi_enabled(EFI_BOOT) || (efi_mem_type(0xa0000) != EFI_CONVENTIONAL_MEMORY))
1257 		vgacon_register_screen(&screen_info);
1258 #endif
1259 #endif
1260 	x86_init.oem.banner();
1261 
1262 	x86_init.timers.wallclock_init();
1263 
1264 	/*
1265 	 * This needs to run before setup_local_APIC() which soft-disables the
1266 	 * local APIC temporarily and that masks the thermal LVT interrupt,
1267 	 * leading to softlockups on machines which have configured SMI
1268 	 * interrupt delivery.
1269 	 */
1270 	therm_lvt_init();
1271 
1272 	mcheck_init();
1273 
1274 	register_refined_jiffies(CLOCK_TICK_RATE);
1275 
1276 #ifdef CONFIG_EFI
1277 	if (efi_enabled(EFI_BOOT))
1278 		efi_apply_memmap_quirks();
1279 #endif
1280 
1281 	unwind_init();
1282 }
1283 
1284 #ifdef CONFIG_X86_32
1285 
1286 static struct resource video_ram_resource = {
1287 	.name	= "Video RAM area",
1288 	.start	= 0xa0000,
1289 	.end	= 0xbffff,
1290 	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM
1291 };
1292 
i386_reserve_resources(void)1293 void __init i386_reserve_resources(void)
1294 {
1295 	request_resource(&iomem_resource, &video_ram_resource);
1296 	reserve_standard_io_resources();
1297 }
1298 
1299 #endif /* CONFIG_X86_32 */
1300 
1301 static struct notifier_block kernel_offset_notifier = {
1302 	.notifier_call = dump_kernel_offset
1303 };
1304 
register_kernel_offset_dumper(void)1305 static int __init register_kernel_offset_dumper(void)
1306 {
1307 	atomic_notifier_chain_register(&panic_notifier_list,
1308 					&kernel_offset_notifier);
1309 	return 0;
1310 }
1311 __initcall(register_kernel_offset_dumper);
1312 
1313 #ifdef CONFIG_HOTPLUG_CPU
arch_cpu_is_hotpluggable(int cpu)1314 bool arch_cpu_is_hotpluggable(int cpu)
1315 {
1316 	return cpu > 0;
1317 }
1318 #endif /* CONFIG_HOTPLUG_CPU */
1319