xref: /openbmc/linux/arch/x86/kernel/setup.c (revision a89a501c)
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/console.h>
9 #include <linux/crash_dump.h>
10 #include <linux/dma-map-ops.h>
11 #include <linux/dmi.h>
12 #include <linux/efi.h>
13 #include <linux/init_ohci1394_dma.h>
14 #include <linux/initrd.h>
15 #include <linux/iscsi_ibft.h>
16 #include <linux/memblock.h>
17 #include <linux/pci.h>
18 #include <linux/root_dev.h>
19 #include <linux/sfi.h>
20 #include <linux/hugetlb.h>
21 #include <linux/tboot.h>
22 #include <linux/usb/xhci-dbgp.h>
23 #include <linux/static_call.h>
24 #include <linux/swiotlb.h>
25 
26 #include <uapi/linux/mount.h>
27 
28 #include <xen/xen.h>
29 
30 #include <asm/apic.h>
31 #include <asm/numa.h>
32 #include <asm/bios_ebda.h>
33 #include <asm/bugs.h>
34 #include <asm/cpu.h>
35 #include <asm/efi.h>
36 #include <asm/gart.h>
37 #include <asm/hypervisor.h>
38 #include <asm/io_apic.h>
39 #include <asm/kasan.h>
40 #include <asm/kaslr.h>
41 #include <asm/mce.h>
42 #include <asm/mtrr.h>
43 #include <asm/realmode.h>
44 #include <asm/olpc_ofw.h>
45 #include <asm/pci-direct.h>
46 #include <asm/prom.h>
47 #include <asm/proto.h>
48 #include <asm/unwind.h>
49 #include <asm/vsyscall.h>
50 #include <linux/vmalloc.h>
51 
52 /*
53  * max_low_pfn_mapped: highest directly mapped pfn < 4 GB
54  * max_pfn_mapped:     highest directly mapped pfn > 4 GB
55  *
56  * The direct mapping only covers E820_TYPE_RAM regions, so the ranges and gaps are
57  * represented by pfn_mapped[].
58  */
59 unsigned long max_low_pfn_mapped;
60 unsigned long max_pfn_mapped;
61 
62 #ifdef CONFIG_DMI
63 RESERVE_BRK(dmi_alloc, 65536);
64 #endif
65 
66 
67 /*
68  * Range of the BSS area. The size of the BSS area is determined
69  * at link time, with RESERVE_BRK*() facility reserving additional
70  * chunks.
71  */
72 unsigned long _brk_start = (unsigned long)__brk_base;
73 unsigned long _brk_end   = (unsigned long)__brk_base;
74 
75 struct boot_params boot_params;
76 
77 /*
78  * These are the four main kernel memory regions, we put them into
79  * the resource tree so that kdump tools and other debugging tools
80  * recover it:
81  */
82 
83 static struct resource rodata_resource = {
84 	.name	= "Kernel rodata",
85 	.start	= 0,
86 	.end	= 0,
87 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
88 };
89 
90 static struct resource data_resource = {
91 	.name	= "Kernel data",
92 	.start	= 0,
93 	.end	= 0,
94 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
95 };
96 
97 static struct resource code_resource = {
98 	.name	= "Kernel code",
99 	.start	= 0,
100 	.end	= 0,
101 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
102 };
103 
104 static struct resource bss_resource = {
105 	.name	= "Kernel bss",
106 	.start	= 0,
107 	.end	= 0,
108 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
109 };
110 
111 
112 #ifdef CONFIG_X86_32
113 /* CPU data as detected by the assembly code in head_32.S */
114 struct cpuinfo_x86 new_cpu_data;
115 
116 /* Common CPU data for all CPUs */
117 struct cpuinfo_x86 boot_cpu_data __read_mostly;
118 EXPORT_SYMBOL(boot_cpu_data);
119 
120 unsigned int def_to_bigsmp;
121 
122 /* For MCA, but anyone else can use it if they want */
123 unsigned int machine_id;
124 unsigned int machine_submodel_id;
125 unsigned int BIOS_revision;
126 
127 struct apm_info apm_info;
128 EXPORT_SYMBOL(apm_info);
129 
130 #if defined(CONFIG_X86_SPEEDSTEP_SMI) || \
131 	defined(CONFIG_X86_SPEEDSTEP_SMI_MODULE)
132 struct ist_info ist_info;
133 EXPORT_SYMBOL(ist_info);
134 #else
135 struct ist_info ist_info;
136 #endif
137 
138 #else
139 struct cpuinfo_x86 boot_cpu_data __read_mostly;
140 EXPORT_SYMBOL(boot_cpu_data);
141 #endif
142 
143 
144 #if !defined(CONFIG_X86_PAE) || defined(CONFIG_X86_64)
145 __visible unsigned long mmu_cr4_features __ro_after_init;
146 #else
147 __visible unsigned long mmu_cr4_features __ro_after_init = X86_CR4_PAE;
148 #endif
149 
150 /* Boot loader ID and version as integers, for the benefit of proc_dointvec */
151 int bootloader_type, bootloader_version;
152 
153 /*
154  * Setup options
155  */
156 struct screen_info screen_info;
157 EXPORT_SYMBOL(screen_info);
158 struct edid_info edid_info;
159 EXPORT_SYMBOL_GPL(edid_info);
160 
161 extern int root_mountflags;
162 
163 unsigned long saved_video_mode;
164 
165 #define RAMDISK_IMAGE_START_MASK	0x07FF
166 #define RAMDISK_PROMPT_FLAG		0x8000
167 #define RAMDISK_LOAD_FLAG		0x4000
168 
169 static char __initdata command_line[COMMAND_LINE_SIZE];
170 #ifdef CONFIG_CMDLINE_BOOL
171 static char __initdata builtin_cmdline[COMMAND_LINE_SIZE] = CONFIG_CMDLINE;
172 #endif
173 
174 #if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
175 struct edd edd;
176 #ifdef CONFIG_EDD_MODULE
177 EXPORT_SYMBOL(edd);
178 #endif
179 /**
180  * copy_edd() - Copy the BIOS EDD information
181  *              from boot_params into a safe place.
182  *
183  */
184 static inline void __init copy_edd(void)
185 {
186      memcpy(edd.mbr_signature, boot_params.edd_mbr_sig_buffer,
187 	    sizeof(edd.mbr_signature));
188      memcpy(edd.edd_info, boot_params.eddbuf, sizeof(edd.edd_info));
189      edd.mbr_signature_nr = boot_params.edd_mbr_sig_buf_entries;
190      edd.edd_info_nr = boot_params.eddbuf_entries;
191 }
192 #else
193 static inline void __init copy_edd(void)
194 {
195 }
196 #endif
197 
198 void * __init extend_brk(size_t size, size_t align)
199 {
200 	size_t mask = align - 1;
201 	void *ret;
202 
203 	BUG_ON(_brk_start == 0);
204 	BUG_ON(align & mask);
205 
206 	_brk_end = (_brk_end + mask) & ~mask;
207 	BUG_ON((char *)(_brk_end + size) > __brk_limit);
208 
209 	ret = (void *)_brk_end;
210 	_brk_end += size;
211 
212 	memset(ret, 0, size);
213 
214 	return ret;
215 }
216 
217 #ifdef CONFIG_X86_32
218 static void __init cleanup_highmap(void)
219 {
220 }
221 #endif
222 
223 static void __init reserve_brk(void)
224 {
225 	if (_brk_end > _brk_start)
226 		memblock_reserve(__pa_symbol(_brk_start),
227 				 _brk_end - _brk_start);
228 
229 	/* Mark brk area as locked down and no longer taking any
230 	   new allocations */
231 	_brk_start = 0;
232 }
233 
234 u64 relocated_ramdisk;
235 
236 #ifdef CONFIG_BLK_DEV_INITRD
237 
238 static u64 __init get_ramdisk_image(void)
239 {
240 	u64 ramdisk_image = boot_params.hdr.ramdisk_image;
241 
242 	ramdisk_image |= (u64)boot_params.ext_ramdisk_image << 32;
243 
244 	if (ramdisk_image == 0)
245 		ramdisk_image = phys_initrd_start;
246 
247 	return ramdisk_image;
248 }
249 static u64 __init get_ramdisk_size(void)
250 {
251 	u64 ramdisk_size = boot_params.hdr.ramdisk_size;
252 
253 	ramdisk_size |= (u64)boot_params.ext_ramdisk_size << 32;
254 
255 	if (ramdisk_size == 0)
256 		ramdisk_size = phys_initrd_size;
257 
258 	return ramdisk_size;
259 }
260 
261 static void __init relocate_initrd(void)
262 {
263 	/* Assume only end is not page aligned */
264 	u64 ramdisk_image = get_ramdisk_image();
265 	u64 ramdisk_size  = get_ramdisk_size();
266 	u64 area_size     = PAGE_ALIGN(ramdisk_size);
267 
268 	/* We need to move the initrd down into directly mapped mem */
269 	relocated_ramdisk = memblock_phys_alloc_range(area_size, PAGE_SIZE, 0,
270 						      PFN_PHYS(max_pfn_mapped));
271 	if (!relocated_ramdisk)
272 		panic("Cannot find place for new RAMDISK of size %lld\n",
273 		      ramdisk_size);
274 
275 	initrd_start = relocated_ramdisk + PAGE_OFFSET;
276 	initrd_end   = initrd_start + ramdisk_size;
277 	printk(KERN_INFO "Allocated new RAMDISK: [mem %#010llx-%#010llx]\n",
278 	       relocated_ramdisk, relocated_ramdisk + ramdisk_size - 1);
279 
280 	copy_from_early_mem((void *)initrd_start, ramdisk_image, ramdisk_size);
281 
282 	printk(KERN_INFO "Move RAMDISK from [mem %#010llx-%#010llx] to"
283 		" [mem %#010llx-%#010llx]\n",
284 		ramdisk_image, ramdisk_image + ramdisk_size - 1,
285 		relocated_ramdisk, relocated_ramdisk + ramdisk_size - 1);
286 }
287 
288 static void __init early_reserve_initrd(void)
289 {
290 	/* Assume only end is not page aligned */
291 	u64 ramdisk_image = get_ramdisk_image();
292 	u64 ramdisk_size  = get_ramdisk_size();
293 	u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
294 
295 	if (!boot_params.hdr.type_of_loader ||
296 	    !ramdisk_image || !ramdisk_size)
297 		return;		/* No initrd provided by bootloader */
298 
299 	memblock_reserve(ramdisk_image, ramdisk_end - ramdisk_image);
300 }
301 
302 static void __init reserve_initrd(void)
303 {
304 	/* Assume only end is not page aligned */
305 	u64 ramdisk_image = get_ramdisk_image();
306 	u64 ramdisk_size  = get_ramdisk_size();
307 	u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
308 
309 	if (!boot_params.hdr.type_of_loader ||
310 	    !ramdisk_image || !ramdisk_size)
311 		return;		/* No initrd provided by bootloader */
312 
313 	initrd_start = 0;
314 
315 	printk(KERN_INFO "RAMDISK: [mem %#010llx-%#010llx]\n", ramdisk_image,
316 			ramdisk_end - 1);
317 
318 	if (pfn_range_is_mapped(PFN_DOWN(ramdisk_image),
319 				PFN_DOWN(ramdisk_end))) {
320 		/* All are mapped, easy case */
321 		initrd_start = ramdisk_image + PAGE_OFFSET;
322 		initrd_end = initrd_start + ramdisk_size;
323 		return;
324 	}
325 
326 	relocate_initrd();
327 
328 	memblock_free(ramdisk_image, ramdisk_end - ramdisk_image);
329 }
330 
331 #else
332 static void __init early_reserve_initrd(void)
333 {
334 }
335 static void __init reserve_initrd(void)
336 {
337 }
338 #endif /* CONFIG_BLK_DEV_INITRD */
339 
340 static void __init parse_setup_data(void)
341 {
342 	struct setup_data *data;
343 	u64 pa_data, pa_next;
344 
345 	pa_data = boot_params.hdr.setup_data;
346 	while (pa_data) {
347 		u32 data_len, data_type;
348 
349 		data = early_memremap(pa_data, sizeof(*data));
350 		data_len = data->len + sizeof(struct setup_data);
351 		data_type = data->type;
352 		pa_next = data->next;
353 		early_memunmap(data, sizeof(*data));
354 
355 		switch (data_type) {
356 		case SETUP_E820_EXT:
357 			e820__memory_setup_extended(pa_data, data_len);
358 			break;
359 		case SETUP_DTB:
360 			add_dtb(pa_data);
361 			break;
362 		case SETUP_EFI:
363 			parse_efi_setup(pa_data, data_len);
364 			break;
365 		default:
366 			break;
367 		}
368 		pa_data = pa_next;
369 	}
370 }
371 
372 static void __init memblock_x86_reserve_range_setup_data(void)
373 {
374 	struct setup_data *data;
375 	u64 pa_data;
376 
377 	pa_data = boot_params.hdr.setup_data;
378 	while (pa_data) {
379 		data = early_memremap(pa_data, sizeof(*data));
380 		memblock_reserve(pa_data, sizeof(*data) + data->len);
381 
382 		if (data->type == SETUP_INDIRECT &&
383 		    ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT)
384 			memblock_reserve(((struct setup_indirect *)data->data)->addr,
385 					 ((struct setup_indirect *)data->data)->len);
386 
387 		pa_data = data->next;
388 		early_memunmap(data, sizeof(*data));
389 	}
390 }
391 
392 /*
393  * --------- Crashkernel reservation ------------------------------
394  */
395 
396 #ifdef CONFIG_KEXEC_CORE
397 
398 /* 16M alignment for crash kernel regions */
399 #define CRASH_ALIGN		SZ_16M
400 
401 /*
402  * Keep the crash kernel below this limit.
403  *
404  * Earlier 32-bits kernels would limit the kernel to the low 512 MB range
405  * due to mapping restrictions.
406  *
407  * 64-bit kdump kernels need to be restricted to be under 64 TB, which is
408  * the upper limit of system RAM in 4-level paging mode. Since the kdump
409  * jump could be from 5-level paging to 4-level paging, the jump will fail if
410  * the kernel is put above 64 TB, and during the 1st kernel bootup there's
411  * no good way to detect the paging mode of the target kernel which will be
412  * loaded for dumping.
413  */
414 #ifdef CONFIG_X86_32
415 # define CRASH_ADDR_LOW_MAX	SZ_512M
416 # define CRASH_ADDR_HIGH_MAX	SZ_512M
417 #else
418 # define CRASH_ADDR_LOW_MAX	SZ_4G
419 # define CRASH_ADDR_HIGH_MAX	SZ_64T
420 #endif
421 
422 static int __init reserve_crashkernel_low(void)
423 {
424 #ifdef CONFIG_X86_64
425 	unsigned long long base, low_base = 0, low_size = 0;
426 	unsigned long low_mem_limit;
427 	int ret;
428 
429 	low_mem_limit = min(memblock_phys_mem_size(), CRASH_ADDR_LOW_MAX);
430 
431 	/* crashkernel=Y,low */
432 	ret = parse_crashkernel_low(boot_command_line, low_mem_limit, &low_size, &base);
433 	if (ret) {
434 		/*
435 		 * two parts from kernel/dma/swiotlb.c:
436 		 * -swiotlb size: user-specified with swiotlb= or default.
437 		 *
438 		 * -swiotlb overflow buffer: now hardcoded to 32k. We round it
439 		 * to 8M for other buffers that may need to stay low too. Also
440 		 * make sure we allocate enough extra low memory so that we
441 		 * don't run out of DMA buffers for 32-bit devices.
442 		 */
443 		low_size = max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20);
444 	} else {
445 		/* passed with crashkernel=0,low ? */
446 		if (!low_size)
447 			return 0;
448 	}
449 
450 	low_base = memblock_phys_alloc_range(low_size, CRASH_ALIGN, 0, CRASH_ADDR_LOW_MAX);
451 	if (!low_base) {
452 		pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n",
453 		       (unsigned long)(low_size >> 20));
454 		return -ENOMEM;
455 	}
456 
457 	pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (low RAM limit: %ldMB)\n",
458 		(unsigned long)(low_size >> 20),
459 		(unsigned long)(low_base >> 20),
460 		(unsigned long)(low_mem_limit >> 20));
461 
462 	crashk_low_res.start = low_base;
463 	crashk_low_res.end   = low_base + low_size - 1;
464 	insert_resource(&iomem_resource, &crashk_low_res);
465 #endif
466 	return 0;
467 }
468 
469 static void __init reserve_crashkernel(void)
470 {
471 	unsigned long long crash_size, crash_base, total_mem;
472 	bool high = false;
473 	int ret;
474 
475 	total_mem = memblock_phys_mem_size();
476 
477 	/* crashkernel=XM */
478 	ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base);
479 	if (ret != 0 || crash_size <= 0) {
480 		/* crashkernel=X,high */
481 		ret = parse_crashkernel_high(boot_command_line, total_mem,
482 					     &crash_size, &crash_base);
483 		if (ret != 0 || crash_size <= 0)
484 			return;
485 		high = true;
486 	}
487 
488 	if (xen_pv_domain()) {
489 		pr_info("Ignoring crashkernel for a Xen PV domain\n");
490 		return;
491 	}
492 
493 	/* 0 means: find the address automatically */
494 	if (!crash_base) {
495 		/*
496 		 * Set CRASH_ADDR_LOW_MAX upper bound for crash memory,
497 		 * crashkernel=x,high reserves memory over 4G, also allocates
498 		 * 256M extra low memory for DMA buffers and swiotlb.
499 		 * But the extra memory is not required for all machines.
500 		 * So try low memory first and fall back to high memory
501 		 * unless "crashkernel=size[KMG],high" is specified.
502 		 */
503 		if (!high)
504 			crash_base = memblock_phys_alloc_range(crash_size,
505 						CRASH_ALIGN, CRASH_ALIGN,
506 						CRASH_ADDR_LOW_MAX);
507 		if (!crash_base)
508 			crash_base = memblock_phys_alloc_range(crash_size,
509 						CRASH_ALIGN, CRASH_ALIGN,
510 						CRASH_ADDR_HIGH_MAX);
511 		if (!crash_base) {
512 			pr_info("crashkernel reservation failed - No suitable area found.\n");
513 			return;
514 		}
515 	} else {
516 		unsigned long long start;
517 
518 		start = memblock_phys_alloc_range(crash_size, SZ_1M, crash_base,
519 						  crash_base + crash_size);
520 		if (start != crash_base) {
521 			pr_info("crashkernel reservation failed - memory is in use.\n");
522 			return;
523 		}
524 	}
525 
526 	if (crash_base >= (1ULL << 32) && reserve_crashkernel_low()) {
527 		memblock_free(crash_base, crash_size);
528 		return;
529 	}
530 
531 	pr_info("Reserving %ldMB of memory at %ldMB for crashkernel (System RAM: %ldMB)\n",
532 		(unsigned long)(crash_size >> 20),
533 		(unsigned long)(crash_base >> 20),
534 		(unsigned long)(total_mem >> 20));
535 
536 	crashk_res.start = crash_base;
537 	crashk_res.end   = crash_base + crash_size - 1;
538 	insert_resource(&iomem_resource, &crashk_res);
539 }
540 #else
541 static void __init reserve_crashkernel(void)
542 {
543 }
544 #endif
545 
546 static struct resource standard_io_resources[] = {
547 	{ .name = "dma1", .start = 0x00, .end = 0x1f,
548 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
549 	{ .name = "pic1", .start = 0x20, .end = 0x21,
550 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
551 	{ .name = "timer0", .start = 0x40, .end = 0x43,
552 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
553 	{ .name = "timer1", .start = 0x50, .end = 0x53,
554 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
555 	{ .name = "keyboard", .start = 0x60, .end = 0x60,
556 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
557 	{ .name = "keyboard", .start = 0x64, .end = 0x64,
558 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
559 	{ .name = "dma page reg", .start = 0x80, .end = 0x8f,
560 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
561 	{ .name = "pic2", .start = 0xa0, .end = 0xa1,
562 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
563 	{ .name = "dma2", .start = 0xc0, .end = 0xdf,
564 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
565 	{ .name = "fpu", .start = 0xf0, .end = 0xff,
566 		.flags = IORESOURCE_BUSY | IORESOURCE_IO }
567 };
568 
569 void __init reserve_standard_io_resources(void)
570 {
571 	int i;
572 
573 	/* request I/O space for devices used on all i[345]86 PCs */
574 	for (i = 0; i < ARRAY_SIZE(standard_io_resources); i++)
575 		request_resource(&ioport_resource, &standard_io_resources[i]);
576 
577 }
578 
579 static __init void reserve_ibft_region(void)
580 {
581 	unsigned long addr, size = 0;
582 
583 	addr = find_ibft_region(&size);
584 
585 	if (size)
586 		memblock_reserve(addr, size);
587 }
588 
589 static bool __init snb_gfx_workaround_needed(void)
590 {
591 #ifdef CONFIG_PCI
592 	int i;
593 	u16 vendor, devid;
594 	static const __initconst u16 snb_ids[] = {
595 		0x0102,
596 		0x0112,
597 		0x0122,
598 		0x0106,
599 		0x0116,
600 		0x0126,
601 		0x010a,
602 	};
603 
604 	/* Assume no if something weird is going on with PCI */
605 	if (!early_pci_allowed())
606 		return false;
607 
608 	vendor = read_pci_config_16(0, 2, 0, PCI_VENDOR_ID);
609 	if (vendor != 0x8086)
610 		return false;
611 
612 	devid = read_pci_config_16(0, 2, 0, PCI_DEVICE_ID);
613 	for (i = 0; i < ARRAY_SIZE(snb_ids); i++)
614 		if (devid == snb_ids[i])
615 			return true;
616 #endif
617 
618 	return false;
619 }
620 
621 /*
622  * Sandy Bridge graphics has trouble with certain ranges, exclude
623  * them from allocation.
624  */
625 static void __init trim_snb_memory(void)
626 {
627 	static const __initconst unsigned long bad_pages[] = {
628 		0x20050000,
629 		0x20110000,
630 		0x20130000,
631 		0x20138000,
632 		0x40004000,
633 	};
634 	int i;
635 
636 	if (!snb_gfx_workaround_needed())
637 		return;
638 
639 	printk(KERN_DEBUG "reserving inaccessible SNB gfx pages\n");
640 
641 	/*
642 	 * Reserve all memory below the 1 MB mark that has not
643 	 * already been reserved.
644 	 */
645 	memblock_reserve(0, 1<<20);
646 
647 	for (i = 0; i < ARRAY_SIZE(bad_pages); i++) {
648 		if (memblock_reserve(bad_pages[i], PAGE_SIZE))
649 			printk(KERN_WARNING "failed to reserve 0x%08lx\n",
650 			       bad_pages[i]);
651 	}
652 }
653 
654 /*
655  * Here we put platform-specific memory range workarounds, i.e.
656  * memory known to be corrupt or otherwise in need to be reserved on
657  * specific platforms.
658  *
659  * If this gets used more widely it could use a real dispatch mechanism.
660  */
661 static void __init trim_platform_memory_ranges(void)
662 {
663 	trim_snb_memory();
664 }
665 
666 static void __init trim_bios_range(void)
667 {
668 	/*
669 	 * A special case is the first 4Kb of memory;
670 	 * This is a BIOS owned area, not kernel ram, but generally
671 	 * not listed as such in the E820 table.
672 	 *
673 	 * This typically reserves additional memory (64KiB by default)
674 	 * since some BIOSes are known to corrupt low memory.  See the
675 	 * Kconfig help text for X86_RESERVE_LOW.
676 	 */
677 	e820__range_update(0, PAGE_SIZE, E820_TYPE_RAM, E820_TYPE_RESERVED);
678 
679 	/*
680 	 * special case: Some BIOSes report the PC BIOS
681 	 * area (640Kb -> 1Mb) as RAM even though it is not.
682 	 * take them out.
683 	 */
684 	e820__range_remove(BIOS_BEGIN, BIOS_END - BIOS_BEGIN, E820_TYPE_RAM, 1);
685 
686 	e820__update_table(e820_table);
687 }
688 
689 /* called before trim_bios_range() to spare extra sanitize */
690 static void __init e820_add_kernel_range(void)
691 {
692 	u64 start = __pa_symbol(_text);
693 	u64 size = __pa_symbol(_end) - start;
694 
695 	/*
696 	 * Complain if .text .data and .bss are not marked as E820_TYPE_RAM and
697 	 * attempt to fix it by adding the range. We may have a confused BIOS,
698 	 * or the user may have used memmap=exactmap or memmap=xxM$yyM to
699 	 * exclude kernel range. If we really are running on top non-RAM,
700 	 * we will crash later anyways.
701 	 */
702 	if (e820__mapped_all(start, start + size, E820_TYPE_RAM))
703 		return;
704 
705 	pr_warn(".text .data .bss are not marked as E820_TYPE_RAM!\n");
706 	e820__range_remove(start, size, E820_TYPE_RAM, 0);
707 	e820__range_add(start, size, E820_TYPE_RAM);
708 }
709 
710 static unsigned reserve_low = CONFIG_X86_RESERVE_LOW << 10;
711 
712 static int __init parse_reservelow(char *p)
713 {
714 	unsigned long long size;
715 
716 	if (!p)
717 		return -EINVAL;
718 
719 	size = memparse(p, &p);
720 
721 	if (size < 4096)
722 		size = 4096;
723 
724 	if (size > 640*1024)
725 		size = 640*1024;
726 
727 	reserve_low = size;
728 
729 	return 0;
730 }
731 
732 early_param("reservelow", parse_reservelow);
733 
734 static void __init trim_low_memory_range(void)
735 {
736 	memblock_reserve(0, ALIGN(reserve_low, PAGE_SIZE));
737 }
738 
739 /*
740  * Dump out kernel offset information on panic.
741  */
742 static int
743 dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
744 {
745 	if (kaslr_enabled()) {
746 		pr_emerg("Kernel Offset: 0x%lx from 0x%lx (relocation range: 0x%lx-0x%lx)\n",
747 			 kaslr_offset(),
748 			 __START_KERNEL,
749 			 __START_KERNEL_map,
750 			 MODULES_VADDR-1);
751 	} else {
752 		pr_emerg("Kernel Offset: disabled\n");
753 	}
754 
755 	return 0;
756 }
757 
758 /*
759  * Determine if we were loaded by an EFI loader.  If so, then we have also been
760  * passed the efi memmap, systab, etc., so we should use these data structures
761  * for initialization.  Note, the efi init code path is determined by the
762  * global efi_enabled. This allows the same kernel image to be used on existing
763  * systems (with a traditional BIOS) as well as on EFI systems.
764  */
765 /*
766  * setup_arch - architecture-specific boot-time initializations
767  *
768  * Note: On x86_64, fixmaps are ready for use even before this is called.
769  */
770 
771 void __init setup_arch(char **cmdline_p)
772 {
773 	/*
774 	 * Reserve the memory occupied by the kernel between _text and
775 	 * __end_of_kernel_reserve symbols. Any kernel sections after the
776 	 * __end_of_kernel_reserve symbol must be explicitly reserved with a
777 	 * separate memblock_reserve() or they will be discarded.
778 	 */
779 	memblock_reserve(__pa_symbol(_text),
780 			 (unsigned long)__end_of_kernel_reserve - (unsigned long)_text);
781 
782 	/*
783 	 * Make sure page 0 is always reserved because on systems with
784 	 * L1TF its contents can be leaked to user processes.
785 	 */
786 	memblock_reserve(0, PAGE_SIZE);
787 
788 	early_reserve_initrd();
789 
790 	/*
791 	 * At this point everything still needed from the boot loader
792 	 * or BIOS or kernel text should be early reserved or marked not
793 	 * RAM in e820. All other memory is free game.
794 	 */
795 
796 #ifdef CONFIG_X86_32
797 	memcpy(&boot_cpu_data, &new_cpu_data, sizeof(new_cpu_data));
798 
799 	/*
800 	 * copy kernel address range established so far and switch
801 	 * to the proper swapper page table
802 	 */
803 	clone_pgd_range(swapper_pg_dir     + KERNEL_PGD_BOUNDARY,
804 			initial_page_table + KERNEL_PGD_BOUNDARY,
805 			KERNEL_PGD_PTRS);
806 
807 	load_cr3(swapper_pg_dir);
808 	/*
809 	 * Note: Quark X1000 CPUs advertise PGE incorrectly and require
810 	 * a cr3 based tlb flush, so the following __flush_tlb_all()
811 	 * will not flush anything because the CPU quirk which clears
812 	 * X86_FEATURE_PGE has not been invoked yet. Though due to the
813 	 * load_cr3() above the TLB has been flushed already. The
814 	 * quirk is invoked before subsequent calls to __flush_tlb_all()
815 	 * so proper operation is guaranteed.
816 	 */
817 	__flush_tlb_all();
818 #else
819 	printk(KERN_INFO "Command line: %s\n", boot_command_line);
820 	boot_cpu_data.x86_phys_bits = MAX_PHYSMEM_BITS;
821 #endif
822 
823 	/*
824 	 * If we have OLPC OFW, we might end up relocating the fixmap due to
825 	 * reserve_top(), so do this before touching the ioremap area.
826 	 */
827 	olpc_ofw_detect();
828 
829 	idt_setup_early_traps();
830 	early_cpu_init();
831 	arch_init_ideal_nops();
832 	jump_label_init();
833 	static_call_init();
834 	early_ioremap_init();
835 
836 	setup_olpc_ofw_pgd();
837 
838 	ROOT_DEV = old_decode_dev(boot_params.hdr.root_dev);
839 	screen_info = boot_params.screen_info;
840 	edid_info = boot_params.edid_info;
841 #ifdef CONFIG_X86_32
842 	apm_info.bios = boot_params.apm_bios_info;
843 	ist_info = boot_params.ist_info;
844 #endif
845 	saved_video_mode = boot_params.hdr.vid_mode;
846 	bootloader_type = boot_params.hdr.type_of_loader;
847 	if ((bootloader_type >> 4) == 0xe) {
848 		bootloader_type &= 0xf;
849 		bootloader_type |= (boot_params.hdr.ext_loader_type+0x10) << 4;
850 	}
851 	bootloader_version  = bootloader_type & 0xf;
852 	bootloader_version |= boot_params.hdr.ext_loader_ver << 4;
853 
854 #ifdef CONFIG_BLK_DEV_RAM
855 	rd_image_start = boot_params.hdr.ram_size & RAMDISK_IMAGE_START_MASK;
856 #endif
857 #ifdef CONFIG_EFI
858 	if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
859 		     EFI32_LOADER_SIGNATURE, 4)) {
860 		set_bit(EFI_BOOT, &efi.flags);
861 	} else if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
862 		     EFI64_LOADER_SIGNATURE, 4)) {
863 		set_bit(EFI_BOOT, &efi.flags);
864 		set_bit(EFI_64BIT, &efi.flags);
865 	}
866 #endif
867 
868 	x86_init.oem.arch_setup();
869 
870 	iomem_resource.end = (1ULL << boot_cpu_data.x86_phys_bits) - 1;
871 	e820__memory_setup();
872 	parse_setup_data();
873 
874 	copy_edd();
875 
876 	if (!boot_params.hdr.root_flags)
877 		root_mountflags &= ~MS_RDONLY;
878 	init_mm.start_code = (unsigned long) _text;
879 	init_mm.end_code = (unsigned long) _etext;
880 	init_mm.end_data = (unsigned long) _edata;
881 	init_mm.brk = _brk_end;
882 
883 	code_resource.start = __pa_symbol(_text);
884 	code_resource.end = __pa_symbol(_etext)-1;
885 	rodata_resource.start = __pa_symbol(__start_rodata);
886 	rodata_resource.end = __pa_symbol(__end_rodata)-1;
887 	data_resource.start = __pa_symbol(_sdata);
888 	data_resource.end = __pa_symbol(_edata)-1;
889 	bss_resource.start = __pa_symbol(__bss_start);
890 	bss_resource.end = __pa_symbol(__bss_stop)-1;
891 
892 #ifdef CONFIG_CMDLINE_BOOL
893 #ifdef CONFIG_CMDLINE_OVERRIDE
894 	strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
895 #else
896 	if (builtin_cmdline[0]) {
897 		/* append boot loader cmdline to builtin */
898 		strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);
899 		strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);
900 		strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
901 	}
902 #endif
903 #endif
904 
905 	strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
906 	*cmdline_p = command_line;
907 
908 	/*
909 	 * x86_configure_nx() is called before parse_early_param() to detect
910 	 * whether hardware doesn't support NX (so that the early EHCI debug
911 	 * console setup can safely call set_fixmap()). It may then be called
912 	 * again from within noexec_setup() during parsing early parameters
913 	 * to honor the respective command line option.
914 	 */
915 	x86_configure_nx();
916 
917 	parse_early_param();
918 
919 	if (efi_enabled(EFI_BOOT))
920 		efi_memblock_x86_reserve_range();
921 #ifdef CONFIG_MEMORY_HOTPLUG
922 	/*
923 	 * Memory used by the kernel cannot be hot-removed because Linux
924 	 * cannot migrate the kernel pages. When memory hotplug is
925 	 * enabled, we should prevent memblock from allocating memory
926 	 * for the kernel.
927 	 *
928 	 * ACPI SRAT records all hotpluggable memory ranges. But before
929 	 * SRAT is parsed, we don't know about it.
930 	 *
931 	 * The kernel image is loaded into memory at very early time. We
932 	 * cannot prevent this anyway. So on NUMA system, we set any
933 	 * node the kernel resides in as un-hotpluggable.
934 	 *
935 	 * Since on modern servers, one node could have double-digit
936 	 * gigabytes memory, we can assume the memory around the kernel
937 	 * image is also un-hotpluggable. So before SRAT is parsed, just
938 	 * allocate memory near the kernel image to try the best to keep
939 	 * the kernel away from hotpluggable memory.
940 	 */
941 	if (movable_node_is_enabled())
942 		memblock_set_bottom_up(true);
943 #endif
944 
945 	x86_report_nx();
946 
947 	/* after early param, so could get panic from serial */
948 	memblock_x86_reserve_range_setup_data();
949 
950 	if (acpi_mps_check()) {
951 #ifdef CONFIG_X86_LOCAL_APIC
952 		disable_apic = 1;
953 #endif
954 		setup_clear_cpu_cap(X86_FEATURE_APIC);
955 	}
956 
957 	e820__reserve_setup_data();
958 	e820__finish_early_params();
959 
960 	if (efi_enabled(EFI_BOOT))
961 		efi_init();
962 
963 	dmi_setup();
964 
965 	/*
966 	 * VMware detection requires dmi to be available, so this
967 	 * needs to be done after dmi_setup(), for the boot CPU.
968 	 */
969 	init_hypervisor_platform();
970 
971 	tsc_early_init();
972 	x86_init.resources.probe_roms();
973 
974 	/* after parse_early_param, so could debug it */
975 	insert_resource(&iomem_resource, &code_resource);
976 	insert_resource(&iomem_resource, &rodata_resource);
977 	insert_resource(&iomem_resource, &data_resource);
978 	insert_resource(&iomem_resource, &bss_resource);
979 
980 	e820_add_kernel_range();
981 	trim_bios_range();
982 #ifdef CONFIG_X86_32
983 	if (ppro_with_ram_bug()) {
984 		e820__range_update(0x70000000ULL, 0x40000ULL, E820_TYPE_RAM,
985 				  E820_TYPE_RESERVED);
986 		e820__update_table(e820_table);
987 		printk(KERN_INFO "fixed physical RAM map:\n");
988 		e820__print_table("bad_ppro");
989 	}
990 #else
991 	early_gart_iommu_check();
992 #endif
993 
994 	/*
995 	 * partially used pages are not usable - thus
996 	 * we are rounding upwards:
997 	 */
998 	max_pfn = e820__end_of_ram_pfn();
999 
1000 	/* update e820 for memory not covered by WB MTRRs */
1001 	mtrr_bp_init();
1002 	if (mtrr_trim_uncached_memory(max_pfn))
1003 		max_pfn = e820__end_of_ram_pfn();
1004 
1005 	max_possible_pfn = max_pfn;
1006 
1007 	/*
1008 	 * This call is required when the CPU does not support PAT. If
1009 	 * mtrr_bp_init() invoked it already via pat_init() the call has no
1010 	 * effect.
1011 	 */
1012 	init_cache_modes();
1013 
1014 	/*
1015 	 * Define random base addresses for memory sections after max_pfn is
1016 	 * defined and before each memory section base is used.
1017 	 */
1018 	kernel_randomize_memory();
1019 
1020 #ifdef CONFIG_X86_32
1021 	/* max_low_pfn get updated here */
1022 	find_low_pfn_range();
1023 #else
1024 	check_x2apic();
1025 
1026 	/* How many end-of-memory variables you have, grandma! */
1027 	/* need this before calling reserve_initrd */
1028 	if (max_pfn > (1UL<<(32 - PAGE_SHIFT)))
1029 		max_low_pfn = e820__end_of_low_ram_pfn();
1030 	else
1031 		max_low_pfn = max_pfn;
1032 
1033 	high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
1034 #endif
1035 
1036 	/*
1037 	 * Find and reserve possible boot-time SMP configuration:
1038 	 */
1039 	find_smp_config();
1040 
1041 	reserve_ibft_region();
1042 
1043 	early_alloc_pgt_buf();
1044 
1045 	/*
1046 	 * Need to conclude brk, before e820__memblock_setup()
1047 	 *  it could use memblock_find_in_range, could overlap with
1048 	 *  brk area.
1049 	 */
1050 	reserve_brk();
1051 
1052 	cleanup_highmap();
1053 
1054 	memblock_set_current_limit(ISA_END_ADDRESS);
1055 	e820__memblock_setup();
1056 
1057 	reserve_bios_regions();
1058 
1059 	efi_fake_memmap();
1060 	efi_find_mirror();
1061 	efi_esrt_init();
1062 	efi_mokvar_table_init();
1063 
1064 	/*
1065 	 * The EFI specification says that boot service code won't be
1066 	 * called after ExitBootServices(). This is, in fact, a lie.
1067 	 */
1068 	efi_reserve_boot_services();
1069 
1070 	/* preallocate 4k for mptable mpc */
1071 	e820__memblock_alloc_reserved_mpc_new();
1072 
1073 #ifdef CONFIG_X86_CHECK_BIOS_CORRUPTION
1074 	setup_bios_corruption_check();
1075 #endif
1076 
1077 #ifdef CONFIG_X86_32
1078 	printk(KERN_DEBUG "initial memory mapped: [mem 0x00000000-%#010lx]\n",
1079 			(max_pfn_mapped<<PAGE_SHIFT) - 1);
1080 #endif
1081 
1082 	reserve_real_mode();
1083 
1084 	trim_platform_memory_ranges();
1085 	trim_low_memory_range();
1086 
1087 	init_mem_mapping();
1088 
1089 	idt_setup_early_pf();
1090 
1091 	/*
1092 	 * Update mmu_cr4_features (and, indirectly, trampoline_cr4_features)
1093 	 * with the current CR4 value.  This may not be necessary, but
1094 	 * auditing all the early-boot CR4 manipulation would be needed to
1095 	 * rule it out.
1096 	 *
1097 	 * Mask off features that don't work outside long mode (just
1098 	 * PCIDE for now).
1099 	 */
1100 	mmu_cr4_features = __read_cr4() & ~X86_CR4_PCIDE;
1101 
1102 	memblock_set_current_limit(get_max_mapped());
1103 
1104 	/*
1105 	 * NOTE: On x86-32, only from this point on, fixmaps are ready for use.
1106 	 */
1107 
1108 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
1109 	if (init_ohci1394_dma_early)
1110 		init_ohci1394_dma_on_all_controllers();
1111 #endif
1112 	/* Allocate bigger log buffer */
1113 	setup_log_buf(1);
1114 
1115 	if (efi_enabled(EFI_BOOT)) {
1116 		switch (boot_params.secure_boot) {
1117 		case efi_secureboot_mode_disabled:
1118 			pr_info("Secure boot disabled\n");
1119 			break;
1120 		case efi_secureboot_mode_enabled:
1121 			pr_info("Secure boot enabled\n");
1122 			break;
1123 		default:
1124 			pr_info("Secure boot could not be determined\n");
1125 			break;
1126 		}
1127 	}
1128 
1129 	reserve_initrd();
1130 
1131 	acpi_table_upgrade();
1132 
1133 	vsmp_init();
1134 
1135 	io_delay_init();
1136 
1137 	early_platform_quirks();
1138 
1139 	/*
1140 	 * Parse the ACPI tables for possible boot-time SMP configuration.
1141 	 */
1142 	acpi_boot_table_init();
1143 
1144 	early_acpi_boot_init();
1145 
1146 	initmem_init();
1147 	dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT);
1148 
1149 	if (boot_cpu_has(X86_FEATURE_GBPAGES))
1150 		hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
1151 
1152 	/*
1153 	 * Reserve memory for crash kernel after SRAT is parsed so that it
1154 	 * won't consume hotpluggable memory.
1155 	 */
1156 	reserve_crashkernel();
1157 
1158 	memblock_find_dma_reserve();
1159 
1160 	if (!early_xdbc_setup_hardware())
1161 		early_xdbc_register_console();
1162 
1163 	x86_init.paging.pagetable_init();
1164 
1165 	kasan_init();
1166 
1167 	/*
1168 	 * Sync back kernel address range.
1169 	 *
1170 	 * FIXME: Can the later sync in setup_cpu_entry_areas() replace
1171 	 * this call?
1172 	 */
1173 	sync_initial_page_table();
1174 
1175 	tboot_probe();
1176 
1177 	map_vsyscall();
1178 
1179 	generic_apic_probe();
1180 
1181 	early_quirks();
1182 
1183 	/*
1184 	 * Read APIC and some other early information from ACPI tables.
1185 	 */
1186 	acpi_boot_init();
1187 	sfi_init();
1188 	x86_dtb_init();
1189 
1190 	/*
1191 	 * get boot-time SMP configuration:
1192 	 */
1193 	get_smp_config();
1194 
1195 	/*
1196 	 * Systems w/o ACPI and mptables might not have it mapped the local
1197 	 * APIC yet, but prefill_possible_map() might need to access it.
1198 	 */
1199 	init_apic_mappings();
1200 
1201 	prefill_possible_map();
1202 
1203 	init_cpu_to_node();
1204 	init_gi_nodes();
1205 
1206 	io_apic_init_mappings();
1207 
1208 	x86_init.hyper.guest_late_init();
1209 
1210 	e820__reserve_resources();
1211 	e820__register_nosave_regions(max_pfn);
1212 
1213 	x86_init.resources.reserve_resources();
1214 
1215 	e820__setup_pci_gap();
1216 
1217 #ifdef CONFIG_VT
1218 #if defined(CONFIG_VGA_CONSOLE)
1219 	if (!efi_enabled(EFI_BOOT) || (efi_mem_type(0xa0000) != EFI_CONVENTIONAL_MEMORY))
1220 		conswitchp = &vga_con;
1221 #endif
1222 #endif
1223 	x86_init.oem.banner();
1224 
1225 	x86_init.timers.wallclock_init();
1226 
1227 	mcheck_init();
1228 
1229 	register_refined_jiffies(CLOCK_TICK_RATE);
1230 
1231 #ifdef CONFIG_EFI
1232 	if (efi_enabled(EFI_BOOT))
1233 		efi_apply_memmap_quirks();
1234 #endif
1235 
1236 	unwind_init();
1237 }
1238 
1239 #ifdef CONFIG_X86_32
1240 
1241 static struct resource video_ram_resource = {
1242 	.name	= "Video RAM area",
1243 	.start	= 0xa0000,
1244 	.end	= 0xbffff,
1245 	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM
1246 };
1247 
1248 void __init i386_reserve_resources(void)
1249 {
1250 	request_resource(&iomem_resource, &video_ram_resource);
1251 	reserve_standard_io_resources();
1252 }
1253 
1254 #endif /* CONFIG_X86_32 */
1255 
1256 static struct notifier_block kernel_offset_notifier = {
1257 	.notifier_call = dump_kernel_offset
1258 };
1259 
1260 static int __init register_kernel_offset_dumper(void)
1261 {
1262 	atomic_notifier_chain_register(&panic_notifier_list,
1263 					&kernel_offset_notifier);
1264 	return 0;
1265 }
1266 __initcall(register_kernel_offset_dumper);
1267