xref: /linux/arch/x86/kernel/setup.c (revision b85d45947951d23cb22d90caecf4c1eb81342c96)
1 /*
2  *  Copyright (C) 1995  Linus Torvalds
3  *
4  *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
5  *
6  *  Memory region support
7  *	David Parsons <orc@pell.chi.il.us>, July-August 1999
8  *
9  *  Added E820 sanitization routine (removes overlapping memory regions);
10  *  Brian Moyle <bmoyle@mvista.com>, February 2001
11  *
12  * Moved CPU detection code to cpu/${cpu}.c
13  *    Patrick Mochel <mochel@osdl.org>, March 2002
14  *
15  *  Provisions for empty E820 memory regions (reported by certain BIOSes).
16  *  Alex Achenbach <xela@slit.de>, December 2002.
17  *
18  */
19 
20 /*
21  * This file handles the architecture-dependent parts of initialization
22  */
23 
24 #include <linux/sched.h>
25 #include <linux/mm.h>
26 #include <linux/mmzone.h>
27 #include <linux/screen_info.h>
28 #include <linux/ioport.h>
29 #include <linux/acpi.h>
30 #include <linux/sfi.h>
31 #include <linux/apm_bios.h>
32 #include <linux/initrd.h>
33 #include <linux/bootmem.h>
34 #include <linux/memblock.h>
35 #include <linux/seq_file.h>
36 #include <linux/console.h>
37 #include <linux/root_dev.h>
38 #include <linux/highmem.h>
39 #include <linux/module.h>
40 #include <linux/efi.h>
41 #include <linux/init.h>
42 #include <linux/edd.h>
43 #include <linux/iscsi_ibft.h>
44 #include <linux/nodemask.h>
45 #include <linux/kexec.h>
46 #include <linux/dmi.h>
47 #include <linux/pfn.h>
48 #include <linux/pci.h>
49 #include <asm/pci-direct.h>
50 #include <linux/init_ohci1394_dma.h>
51 #include <linux/kvm_para.h>
52 #include <linux/dma-contiguous.h>
53 
54 #include <linux/errno.h>
55 #include <linux/kernel.h>
56 #include <linux/stddef.h>
57 #include <linux/unistd.h>
58 #include <linux/ptrace.h>
59 #include <linux/user.h>
60 #include <linux/delay.h>
61 
62 #include <linux/kallsyms.h>
63 #include <linux/cpufreq.h>
64 #include <linux/dma-mapping.h>
65 #include <linux/ctype.h>
66 #include <linux/uaccess.h>
67 
68 #include <linux/percpu.h>
69 #include <linux/crash_dump.h>
70 #include <linux/tboot.h>
71 #include <linux/jiffies.h>
72 
73 #include <video/edid.h>
74 
75 #include <asm/mtrr.h>
76 #include <asm/apic.h>
77 #include <asm/realmode.h>
78 #include <asm/e820.h>
79 #include <asm/mpspec.h>
80 #include <asm/setup.h>
81 #include <asm/efi.h>
82 #include <asm/timer.h>
83 #include <asm/i8259.h>
84 #include <asm/sections.h>
85 #include <asm/io_apic.h>
86 #include <asm/ist.h>
87 #include <asm/setup_arch.h>
88 #include <asm/bios_ebda.h>
89 #include <asm/cacheflush.h>
90 #include <asm/processor.h>
91 #include <asm/bugs.h>
92 #include <asm/kasan.h>
93 
94 #include <asm/vsyscall.h>
95 #include <asm/cpu.h>
96 #include <asm/desc.h>
97 #include <asm/dma.h>
98 #include <asm/iommu.h>
99 #include <asm/gart.h>
100 #include <asm/mmu_context.h>
101 #include <asm/proto.h>
102 
103 #include <asm/paravirt.h>
104 #include <asm/hypervisor.h>
105 #include <asm/olpc_ofw.h>
106 
107 #include <asm/percpu.h>
108 #include <asm/topology.h>
109 #include <asm/apicdef.h>
110 #include <asm/amd_nb.h>
111 #include <asm/mce.h>
112 #include <asm/alternative.h>
113 #include <asm/prom.h>
114 
115 /*
116  * max_low_pfn_mapped: highest direct mapped pfn under 4GB
117  * max_pfn_mapped:     highest direct mapped pfn over 4GB
118  *
119  * The direct mapping only covers E820_RAM regions, so the ranges and gaps are
120  * represented by pfn_mapped
121  */
122 unsigned long max_low_pfn_mapped;
123 unsigned long max_pfn_mapped;
124 
125 #ifdef CONFIG_DMI
126 RESERVE_BRK(dmi_alloc, 65536);
127 #endif
128 
129 
130 static __initdata unsigned long _brk_start = (unsigned long)__brk_base;
131 unsigned long _brk_end = (unsigned long)__brk_base;
132 
133 #ifdef CONFIG_X86_64
134 int default_cpu_present_to_apicid(int mps_cpu)
135 {
136 	return __default_cpu_present_to_apicid(mps_cpu);
137 }
138 
139 int default_check_phys_apicid_present(int phys_apicid)
140 {
141 	return __default_check_phys_apicid_present(phys_apicid);
142 }
143 #endif
144 
145 struct boot_params boot_params;
146 
147 /*
148  * Machine setup..
149  */
150 static struct resource data_resource = {
151 	.name	= "Kernel data",
152 	.start	= 0,
153 	.end	= 0,
154 	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM
155 };
156 
157 static struct resource code_resource = {
158 	.name	= "Kernel code",
159 	.start	= 0,
160 	.end	= 0,
161 	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM
162 };
163 
164 static struct resource bss_resource = {
165 	.name	= "Kernel bss",
166 	.start	= 0,
167 	.end	= 0,
168 	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM
169 };
170 
171 
172 #ifdef CONFIG_X86_32
173 /* cpu data as detected by the assembly code in head.S */
174 struct cpuinfo_x86 new_cpu_data = {
175 	.wp_works_ok = -1,
176 };
177 /* common cpu data for all cpus */
178 struct cpuinfo_x86 boot_cpu_data __read_mostly = {
179 	.wp_works_ok = -1,
180 };
181 EXPORT_SYMBOL(boot_cpu_data);
182 
183 unsigned int def_to_bigsmp;
184 
185 /* for MCA, but anyone else can use it if they want */
186 unsigned int machine_id;
187 unsigned int machine_submodel_id;
188 unsigned int BIOS_revision;
189 
190 struct apm_info apm_info;
191 EXPORT_SYMBOL(apm_info);
192 
193 #if defined(CONFIG_X86_SPEEDSTEP_SMI) || \
194 	defined(CONFIG_X86_SPEEDSTEP_SMI_MODULE)
195 struct ist_info ist_info;
196 EXPORT_SYMBOL(ist_info);
197 #else
198 struct ist_info ist_info;
199 #endif
200 
201 #else
202 struct cpuinfo_x86 boot_cpu_data __read_mostly = {
203 	.x86_phys_bits = MAX_PHYSMEM_BITS,
204 };
205 EXPORT_SYMBOL(boot_cpu_data);
206 #endif
207 
208 
209 #if !defined(CONFIG_X86_PAE) || defined(CONFIG_X86_64)
210 __visible unsigned long mmu_cr4_features;
211 #else
212 __visible unsigned long mmu_cr4_features = X86_CR4_PAE;
213 #endif
214 
215 /* Boot loader ID and version as integers, for the benefit of proc_dointvec */
216 int bootloader_type, bootloader_version;
217 
218 /*
219  * Setup options
220  */
221 struct screen_info screen_info;
222 EXPORT_SYMBOL(screen_info);
223 struct edid_info edid_info;
224 EXPORT_SYMBOL_GPL(edid_info);
225 
226 extern int root_mountflags;
227 
228 unsigned long saved_video_mode;
229 
230 #define RAMDISK_IMAGE_START_MASK	0x07FF
231 #define RAMDISK_PROMPT_FLAG		0x8000
232 #define RAMDISK_LOAD_FLAG		0x4000
233 
234 static char __initdata command_line[COMMAND_LINE_SIZE];
235 #ifdef CONFIG_CMDLINE_BOOL
236 static char __initdata builtin_cmdline[COMMAND_LINE_SIZE] = CONFIG_CMDLINE;
237 #endif
238 
239 #if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
240 struct edd edd;
241 #ifdef CONFIG_EDD_MODULE
242 EXPORT_SYMBOL(edd);
243 #endif
244 /**
245  * copy_edd() - Copy the BIOS EDD information
246  *              from boot_params into a safe place.
247  *
248  */
249 static inline void __init copy_edd(void)
250 {
251      memcpy(edd.mbr_signature, boot_params.edd_mbr_sig_buffer,
252 	    sizeof(edd.mbr_signature));
253      memcpy(edd.edd_info, boot_params.eddbuf, sizeof(edd.edd_info));
254      edd.mbr_signature_nr = boot_params.edd_mbr_sig_buf_entries;
255      edd.edd_info_nr = boot_params.eddbuf_entries;
256 }
257 #else
258 static inline void __init copy_edd(void)
259 {
260 }
261 #endif
262 
263 void * __init extend_brk(size_t size, size_t align)
264 {
265 	size_t mask = align - 1;
266 	void *ret;
267 
268 	BUG_ON(_brk_start == 0);
269 	BUG_ON(align & mask);
270 
271 	_brk_end = (_brk_end + mask) & ~mask;
272 	BUG_ON((char *)(_brk_end + size) > __brk_limit);
273 
274 	ret = (void *)_brk_end;
275 	_brk_end += size;
276 
277 	memset(ret, 0, size);
278 
279 	return ret;
280 }
281 
282 #ifdef CONFIG_X86_32
283 static void __init cleanup_highmap(void)
284 {
285 }
286 #endif
287 
288 static void __init reserve_brk(void)
289 {
290 	if (_brk_end > _brk_start)
291 		memblock_reserve(__pa_symbol(_brk_start),
292 				 _brk_end - _brk_start);
293 
294 	/* Mark brk area as locked down and no longer taking any
295 	   new allocations */
296 	_brk_start = 0;
297 }
298 
299 u64 relocated_ramdisk;
300 
301 #ifdef CONFIG_BLK_DEV_INITRD
302 
303 static u64 __init get_ramdisk_image(void)
304 {
305 	u64 ramdisk_image = boot_params.hdr.ramdisk_image;
306 
307 	ramdisk_image |= (u64)boot_params.ext_ramdisk_image << 32;
308 
309 	return ramdisk_image;
310 }
311 static u64 __init get_ramdisk_size(void)
312 {
313 	u64 ramdisk_size = boot_params.hdr.ramdisk_size;
314 
315 	ramdisk_size |= (u64)boot_params.ext_ramdisk_size << 32;
316 
317 	return ramdisk_size;
318 }
319 
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 
327 	/* We need to move the initrd down into directly mapped mem */
328 	relocated_ramdisk = memblock_find_in_range(0, PFN_PHYS(max_pfn_mapped),
329 						   area_size, PAGE_SIZE);
330 
331 	if (!relocated_ramdisk)
332 		panic("Cannot find place for new RAMDISK of size %lld\n",
333 		      ramdisk_size);
334 
335 	/* Note: this includes all the mem currently occupied by
336 	   the initrd, we rely on that fact to keep the data intact. */
337 	memblock_reserve(relocated_ramdisk, area_size);
338 	initrd_start = relocated_ramdisk + PAGE_OFFSET;
339 	initrd_end   = initrd_start + ramdisk_size;
340 	printk(KERN_INFO "Allocated new RAMDISK: [mem %#010llx-%#010llx]\n",
341 	       relocated_ramdisk, relocated_ramdisk + ramdisk_size - 1);
342 
343 	copy_from_early_mem((void *)initrd_start, ramdisk_image, ramdisk_size);
344 
345 	printk(KERN_INFO "Move RAMDISK from [mem %#010llx-%#010llx] to"
346 		" [mem %#010llx-%#010llx]\n",
347 		ramdisk_image, ramdisk_image + ramdisk_size - 1,
348 		relocated_ramdisk, relocated_ramdisk + ramdisk_size - 1);
349 }
350 
351 static void __init early_reserve_initrd(void)
352 {
353 	/* Assume only end is not page aligned */
354 	u64 ramdisk_image = get_ramdisk_image();
355 	u64 ramdisk_size  = get_ramdisk_size();
356 	u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
357 
358 	if (!boot_params.hdr.type_of_loader ||
359 	    !ramdisk_image || !ramdisk_size)
360 		return;		/* No initrd provided by bootloader */
361 
362 	memblock_reserve(ramdisk_image, ramdisk_end - ramdisk_image);
363 }
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 	u64 mapped_size;
371 
372 	if (!boot_params.hdr.type_of_loader ||
373 	    !ramdisk_image || !ramdisk_size)
374 		return;		/* No initrd provided by bootloader */
375 
376 	initrd_start = 0;
377 
378 	mapped_size = memblock_mem_size(max_pfn_mapped);
379 	if (ramdisk_size >= (mapped_size>>1))
380 		panic("initrd too large to handle, "
381 		       "disabling initrd (%lld needed, %lld available)\n",
382 		       ramdisk_size, mapped_size>>1);
383 
384 	printk(KERN_INFO "RAMDISK: [mem %#010llx-%#010llx]\n", ramdisk_image,
385 			ramdisk_end - 1);
386 
387 	if (pfn_range_is_mapped(PFN_DOWN(ramdisk_image),
388 				PFN_DOWN(ramdisk_end))) {
389 		/* All are mapped, easy case */
390 		initrd_start = ramdisk_image + PAGE_OFFSET;
391 		initrd_end = initrd_start + ramdisk_size;
392 		return;
393 	}
394 
395 	relocate_initrd();
396 
397 	memblock_free(ramdisk_image, ramdisk_end - ramdisk_image);
398 }
399 #else
400 static void __init early_reserve_initrd(void)
401 {
402 }
403 static void __init reserve_initrd(void)
404 {
405 }
406 #endif /* CONFIG_BLK_DEV_INITRD */
407 
408 static void __init parse_setup_data(void)
409 {
410 	struct setup_data *data;
411 	u64 pa_data, pa_next;
412 
413 	pa_data = boot_params.hdr.setup_data;
414 	while (pa_data) {
415 		u32 data_len, data_type;
416 
417 		data = early_memremap(pa_data, sizeof(*data));
418 		data_len = data->len + sizeof(struct setup_data);
419 		data_type = data->type;
420 		pa_next = data->next;
421 		early_memunmap(data, sizeof(*data));
422 
423 		switch (data_type) {
424 		case SETUP_E820_EXT:
425 			parse_e820_ext(pa_data, data_len);
426 			break;
427 		case SETUP_DTB:
428 			add_dtb(pa_data);
429 			break;
430 		case SETUP_EFI:
431 			parse_efi_setup(pa_data, data_len);
432 			break;
433 		default:
434 			break;
435 		}
436 		pa_data = pa_next;
437 	}
438 }
439 
440 static void __init e820_reserve_setup_data(void)
441 {
442 	struct setup_data *data;
443 	u64 pa_data;
444 
445 	pa_data = boot_params.hdr.setup_data;
446 	if (!pa_data)
447 		return;
448 
449 	while (pa_data) {
450 		data = early_memremap(pa_data, sizeof(*data));
451 		e820_update_range(pa_data, sizeof(*data)+data->len,
452 			 E820_RAM, E820_RESERVED_KERN);
453 		pa_data = data->next;
454 		early_memunmap(data, sizeof(*data));
455 	}
456 
457 	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
458 	memcpy(&e820_saved, &e820, sizeof(struct e820map));
459 	printk(KERN_INFO "extended physical RAM map:\n");
460 	e820_print_map("reserve setup_data");
461 }
462 
463 static void __init memblock_x86_reserve_range_setup_data(void)
464 {
465 	struct setup_data *data;
466 	u64 pa_data;
467 
468 	pa_data = boot_params.hdr.setup_data;
469 	while (pa_data) {
470 		data = early_memremap(pa_data, sizeof(*data));
471 		memblock_reserve(pa_data, sizeof(*data) + data->len);
472 		pa_data = data->next;
473 		early_memunmap(data, sizeof(*data));
474 	}
475 }
476 
477 /*
478  * --------- Crashkernel reservation ------------------------------
479  */
480 
481 #ifdef CONFIG_KEXEC_CORE
482 
483 /*
484  * Keep the crash kernel below this limit.  On 32 bits earlier kernels
485  * would limit the kernel to the low 512 MiB due to mapping restrictions.
486  * On 64bit, old kexec-tools need to under 896MiB.
487  */
488 #ifdef CONFIG_X86_32
489 # define CRASH_KERNEL_ADDR_LOW_MAX	(512 << 20)
490 # define CRASH_KERNEL_ADDR_HIGH_MAX	(512 << 20)
491 #else
492 # define CRASH_KERNEL_ADDR_LOW_MAX	(896UL<<20)
493 # define CRASH_KERNEL_ADDR_HIGH_MAX	MAXMEM
494 #endif
495 
496 static void __init reserve_crashkernel_low(void)
497 {
498 #ifdef CONFIG_X86_64
499 	const unsigned long long alignment = 16<<20;	/* 16M */
500 	unsigned long long low_base = 0, low_size = 0;
501 	unsigned long total_low_mem;
502 	unsigned long long base;
503 	bool auto_set = false;
504 	int ret;
505 
506 	total_low_mem = memblock_mem_size(1UL<<(32-PAGE_SHIFT));
507 	/* crashkernel=Y,low */
508 	ret = parse_crashkernel_low(boot_command_line, total_low_mem,
509 						&low_size, &base);
510 	if (ret != 0) {
511 		/*
512 		 * two parts from lib/swiotlb.c:
513 		 * -swiotlb size: user-specified with swiotlb= or default.
514 		 *
515 		 * -swiotlb overflow buffer: now hardcoded to 32k. We round it
516 		 * to 8M for other buffers that may need to stay low too. Also
517 		 * make sure we allocate enough extra low memory so that we
518 		 * don't run out of DMA buffers for 32-bit devices.
519 		 */
520 		low_size = max(swiotlb_size_or_default() + (8UL<<20), 256UL<<20);
521 		auto_set = true;
522 	} else {
523 		/* passed with crashkernel=0,low ? */
524 		if (!low_size)
525 			return;
526 	}
527 
528 	low_base = memblock_find_in_range(low_size, (1ULL<<32),
529 					low_size, alignment);
530 
531 	if (!low_base) {
532 		if (!auto_set)
533 			pr_info("crashkernel low reservation failed - No suitable area found.\n");
534 
535 		return;
536 	}
537 
538 	memblock_reserve(low_base, low_size);
539 	pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (System low RAM: %ldMB)\n",
540 			(unsigned long)(low_size >> 20),
541 			(unsigned long)(low_base >> 20),
542 			(unsigned long)(total_low_mem >> 20));
543 	crashk_low_res.start = low_base;
544 	crashk_low_res.end   = low_base + low_size - 1;
545 	insert_resource(&iomem_resource, &crashk_low_res);
546 #endif
547 }
548 
549 static void __init reserve_crashkernel(void)
550 {
551 	const unsigned long long alignment = 16<<20;	/* 16M */
552 	unsigned long long total_mem;
553 	unsigned long long crash_size, crash_base;
554 	bool high = false;
555 	int ret;
556 
557 	total_mem = memblock_phys_mem_size();
558 
559 	/* crashkernel=XM */
560 	ret = parse_crashkernel(boot_command_line, total_mem,
561 			&crash_size, &crash_base);
562 	if (ret != 0 || crash_size <= 0) {
563 		/* crashkernel=X,high */
564 		ret = parse_crashkernel_high(boot_command_line, total_mem,
565 				&crash_size, &crash_base);
566 		if (ret != 0 || crash_size <= 0)
567 			return;
568 		high = true;
569 	}
570 
571 	/* 0 means: find the address automatically */
572 	if (crash_base <= 0) {
573 		/*
574 		 *  kexec want bzImage is below CRASH_KERNEL_ADDR_MAX
575 		 */
576 		crash_base = memblock_find_in_range(alignment,
577 					high ? CRASH_KERNEL_ADDR_HIGH_MAX :
578 					       CRASH_KERNEL_ADDR_LOW_MAX,
579 					crash_size, alignment);
580 
581 		if (!crash_base) {
582 			pr_info("crashkernel reservation failed - No suitable area found.\n");
583 			return;
584 		}
585 
586 	} else {
587 		unsigned long long start;
588 
589 		start = memblock_find_in_range(crash_base,
590 				 crash_base + crash_size, crash_size, 1<<20);
591 		if (start != crash_base) {
592 			pr_info("crashkernel reservation failed - memory is in use.\n");
593 			return;
594 		}
595 	}
596 	memblock_reserve(crash_base, crash_size);
597 
598 	printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
599 			"for crashkernel (System RAM: %ldMB)\n",
600 			(unsigned long)(crash_size >> 20),
601 			(unsigned long)(crash_base >> 20),
602 			(unsigned long)(total_mem >> 20));
603 
604 	crashk_res.start = crash_base;
605 	crashk_res.end   = crash_base + crash_size - 1;
606 	insert_resource(&iomem_resource, &crashk_res);
607 
608 	if (crash_base >= (1ULL<<32))
609 		reserve_crashkernel_low();
610 }
611 #else
612 static void __init reserve_crashkernel(void)
613 {
614 }
615 #endif
616 
617 static struct resource standard_io_resources[] = {
618 	{ .name = "dma1", .start = 0x00, .end = 0x1f,
619 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
620 	{ .name = "pic1", .start = 0x20, .end = 0x21,
621 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
622 	{ .name = "timer0", .start = 0x40, .end = 0x43,
623 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
624 	{ .name = "timer1", .start = 0x50, .end = 0x53,
625 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
626 	{ .name = "keyboard", .start = 0x60, .end = 0x60,
627 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
628 	{ .name = "keyboard", .start = 0x64, .end = 0x64,
629 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
630 	{ .name = "dma page reg", .start = 0x80, .end = 0x8f,
631 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
632 	{ .name = "pic2", .start = 0xa0, .end = 0xa1,
633 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
634 	{ .name = "dma2", .start = 0xc0, .end = 0xdf,
635 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
636 	{ .name = "fpu", .start = 0xf0, .end = 0xff,
637 		.flags = IORESOURCE_BUSY | IORESOURCE_IO }
638 };
639 
640 void __init reserve_standard_io_resources(void)
641 {
642 	int i;
643 
644 	/* request I/O space for devices used on all i[345]86 PCs */
645 	for (i = 0; i < ARRAY_SIZE(standard_io_resources); i++)
646 		request_resource(&ioport_resource, &standard_io_resources[i]);
647 
648 }
649 
650 static __init void reserve_ibft_region(void)
651 {
652 	unsigned long addr, size = 0;
653 
654 	addr = find_ibft_region(&size);
655 
656 	if (size)
657 		memblock_reserve(addr, size);
658 }
659 
660 static bool __init snb_gfx_workaround_needed(void)
661 {
662 #ifdef CONFIG_PCI
663 	int i;
664 	u16 vendor, devid;
665 	static const __initconst u16 snb_ids[] = {
666 		0x0102,
667 		0x0112,
668 		0x0122,
669 		0x0106,
670 		0x0116,
671 		0x0126,
672 		0x010a,
673 	};
674 
675 	/* Assume no if something weird is going on with PCI */
676 	if (!early_pci_allowed())
677 		return false;
678 
679 	vendor = read_pci_config_16(0, 2, 0, PCI_VENDOR_ID);
680 	if (vendor != 0x8086)
681 		return false;
682 
683 	devid = read_pci_config_16(0, 2, 0, PCI_DEVICE_ID);
684 	for (i = 0; i < ARRAY_SIZE(snb_ids); i++)
685 		if (devid == snb_ids[i])
686 			return true;
687 #endif
688 
689 	return false;
690 }
691 
692 /*
693  * Sandy Bridge graphics has trouble with certain ranges, exclude
694  * them from allocation.
695  */
696 static void __init trim_snb_memory(void)
697 {
698 	static const __initconst unsigned long bad_pages[] = {
699 		0x20050000,
700 		0x20110000,
701 		0x20130000,
702 		0x20138000,
703 		0x40004000,
704 	};
705 	int i;
706 
707 	if (!snb_gfx_workaround_needed())
708 		return;
709 
710 	printk(KERN_DEBUG "reserving inaccessible SNB gfx pages\n");
711 
712 	/*
713 	 * Reserve all memory below the 1 MB mark that has not
714 	 * already been reserved.
715 	 */
716 	memblock_reserve(0, 1<<20);
717 
718 	for (i = 0; i < ARRAY_SIZE(bad_pages); i++) {
719 		if (memblock_reserve(bad_pages[i], PAGE_SIZE))
720 			printk(KERN_WARNING "failed to reserve 0x%08lx\n",
721 			       bad_pages[i]);
722 	}
723 }
724 
725 /*
726  * Here we put platform-specific memory range workarounds, i.e.
727  * memory known to be corrupt or otherwise in need to be reserved on
728  * specific platforms.
729  *
730  * If this gets used more widely it could use a real dispatch mechanism.
731  */
732 static void __init trim_platform_memory_ranges(void)
733 {
734 	trim_snb_memory();
735 }
736 
737 static void __init trim_bios_range(void)
738 {
739 	/*
740 	 * A special case is the first 4Kb of memory;
741 	 * This is a BIOS owned area, not kernel ram, but generally
742 	 * not listed as such in the E820 table.
743 	 *
744 	 * This typically reserves additional memory (64KiB by default)
745 	 * since some BIOSes are known to corrupt low memory.  See the
746 	 * Kconfig help text for X86_RESERVE_LOW.
747 	 */
748 	e820_update_range(0, PAGE_SIZE, E820_RAM, E820_RESERVED);
749 
750 	/*
751 	 * special case: Some BIOSen report the PC BIOS
752 	 * area (640->1Mb) as ram even though it is not.
753 	 * take them out.
754 	 */
755 	e820_remove_range(BIOS_BEGIN, BIOS_END - BIOS_BEGIN, E820_RAM, 1);
756 
757 	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
758 }
759 
760 /* called before trim_bios_range() to spare extra sanitize */
761 static void __init e820_add_kernel_range(void)
762 {
763 	u64 start = __pa_symbol(_text);
764 	u64 size = __pa_symbol(_end) - start;
765 
766 	/*
767 	 * Complain if .text .data and .bss are not marked as E820_RAM and
768 	 * attempt to fix it by adding the range. We may have a confused BIOS,
769 	 * or the user may have used memmap=exactmap or memmap=xxM$yyM to
770 	 * exclude kernel range. If we really are running on top non-RAM,
771 	 * we will crash later anyways.
772 	 */
773 	if (e820_all_mapped(start, start + size, E820_RAM))
774 		return;
775 
776 	pr_warn(".text .data .bss are not marked as E820_RAM!\n");
777 	e820_remove_range(start, size, E820_RAM, 0);
778 	e820_add_region(start, size, E820_RAM);
779 }
780 
781 static unsigned reserve_low = CONFIG_X86_RESERVE_LOW << 10;
782 
783 static int __init parse_reservelow(char *p)
784 {
785 	unsigned long long size;
786 
787 	if (!p)
788 		return -EINVAL;
789 
790 	size = memparse(p, &p);
791 
792 	if (size < 4096)
793 		size = 4096;
794 
795 	if (size > 640*1024)
796 		size = 640*1024;
797 
798 	reserve_low = size;
799 
800 	return 0;
801 }
802 
803 early_param("reservelow", parse_reservelow);
804 
805 static void __init trim_low_memory_range(void)
806 {
807 	memblock_reserve(0, ALIGN(reserve_low, PAGE_SIZE));
808 }
809 
810 /*
811  * Dump out kernel offset information on panic.
812  */
813 static int
814 dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
815 {
816 	if (kaslr_enabled()) {
817 		pr_emerg("Kernel Offset: 0x%lx from 0x%lx (relocation range: 0x%lx-0x%lx)\n",
818 			 kaslr_offset(),
819 			 __START_KERNEL,
820 			 __START_KERNEL_map,
821 			 MODULES_VADDR-1);
822 	} else {
823 		pr_emerg("Kernel Offset: disabled\n");
824 	}
825 
826 	return 0;
827 }
828 
829 /*
830  * Determine if we were loaded by an EFI loader.  If so, then we have also been
831  * passed the efi memmap, systab, etc., so we should use these data structures
832  * for initialization.  Note, the efi init code path is determined by the
833  * global efi_enabled. This allows the same kernel image to be used on existing
834  * systems (with a traditional BIOS) as well as on EFI systems.
835  */
836 /*
837  * setup_arch - architecture-specific boot-time initializations
838  *
839  * Note: On x86_64, fixmaps are ready for use even before this is called.
840  */
841 
842 void __init setup_arch(char **cmdline_p)
843 {
844 	memblock_reserve(__pa_symbol(_text),
845 			 (unsigned long)__bss_stop - (unsigned long)_text);
846 
847 	early_reserve_initrd();
848 
849 	/*
850 	 * At this point everything still needed from the boot loader
851 	 * or BIOS or kernel text should be early reserved or marked not
852 	 * RAM in e820. All other memory is free game.
853 	 */
854 
855 #ifdef CONFIG_X86_32
856 	memcpy(&boot_cpu_data, &new_cpu_data, sizeof(new_cpu_data));
857 
858 	/*
859 	 * copy kernel address range established so far and switch
860 	 * to the proper swapper page table
861 	 */
862 	clone_pgd_range(swapper_pg_dir     + KERNEL_PGD_BOUNDARY,
863 			initial_page_table + KERNEL_PGD_BOUNDARY,
864 			KERNEL_PGD_PTRS);
865 
866 	load_cr3(swapper_pg_dir);
867 	/*
868 	 * Note: Quark X1000 CPUs advertise PGE incorrectly and require
869 	 * a cr3 based tlb flush, so the following __flush_tlb_all()
870 	 * will not flush anything because the cpu quirk which clears
871 	 * X86_FEATURE_PGE has not been invoked yet. Though due to the
872 	 * load_cr3() above the TLB has been flushed already. The
873 	 * quirk is invoked before subsequent calls to __flush_tlb_all()
874 	 * so proper operation is guaranteed.
875 	 */
876 	__flush_tlb_all();
877 #else
878 	printk(KERN_INFO "Command line: %s\n", boot_command_line);
879 #endif
880 
881 	/*
882 	 * If we have OLPC OFW, we might end up relocating the fixmap due to
883 	 * reserve_top(), so do this before touching the ioremap area.
884 	 */
885 	olpc_ofw_detect();
886 
887 	early_trap_init();
888 	early_cpu_init();
889 	early_ioremap_init();
890 
891 	setup_olpc_ofw_pgd();
892 
893 	ROOT_DEV = old_decode_dev(boot_params.hdr.root_dev);
894 	screen_info = boot_params.screen_info;
895 	edid_info = boot_params.edid_info;
896 #ifdef CONFIG_X86_32
897 	apm_info.bios = boot_params.apm_bios_info;
898 	ist_info = boot_params.ist_info;
899 #endif
900 	saved_video_mode = boot_params.hdr.vid_mode;
901 	bootloader_type = boot_params.hdr.type_of_loader;
902 	if ((bootloader_type >> 4) == 0xe) {
903 		bootloader_type &= 0xf;
904 		bootloader_type |= (boot_params.hdr.ext_loader_type+0x10) << 4;
905 	}
906 	bootloader_version  = bootloader_type & 0xf;
907 	bootloader_version |= boot_params.hdr.ext_loader_ver << 4;
908 
909 #ifdef CONFIG_BLK_DEV_RAM
910 	rd_image_start = boot_params.hdr.ram_size & RAMDISK_IMAGE_START_MASK;
911 	rd_prompt = ((boot_params.hdr.ram_size & RAMDISK_PROMPT_FLAG) != 0);
912 	rd_doload = ((boot_params.hdr.ram_size & RAMDISK_LOAD_FLAG) != 0);
913 #endif
914 #ifdef CONFIG_EFI
915 	if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
916 		     EFI32_LOADER_SIGNATURE, 4)) {
917 		set_bit(EFI_BOOT, &efi.flags);
918 	} else if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
919 		     EFI64_LOADER_SIGNATURE, 4)) {
920 		set_bit(EFI_BOOT, &efi.flags);
921 		set_bit(EFI_64BIT, &efi.flags);
922 	}
923 
924 	if (efi_enabled(EFI_BOOT))
925 		efi_memblock_x86_reserve_range();
926 #endif
927 
928 	x86_init.oem.arch_setup();
929 
930 	iomem_resource.end = (1ULL << boot_cpu_data.x86_phys_bits) - 1;
931 	setup_memory_map();
932 	parse_setup_data();
933 
934 	copy_edd();
935 
936 	if (!boot_params.hdr.root_flags)
937 		root_mountflags &= ~MS_RDONLY;
938 	init_mm.start_code = (unsigned long) _text;
939 	init_mm.end_code = (unsigned long) _etext;
940 	init_mm.end_data = (unsigned long) _edata;
941 	init_mm.brk = _brk_end;
942 
943 	mpx_mm_init(&init_mm);
944 
945 	code_resource.start = __pa_symbol(_text);
946 	code_resource.end = __pa_symbol(_etext)-1;
947 	data_resource.start = __pa_symbol(_etext);
948 	data_resource.end = __pa_symbol(_edata)-1;
949 	bss_resource.start = __pa_symbol(__bss_start);
950 	bss_resource.end = __pa_symbol(__bss_stop)-1;
951 
952 #ifdef CONFIG_CMDLINE_BOOL
953 #ifdef CONFIG_CMDLINE_OVERRIDE
954 	strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
955 #else
956 	if (builtin_cmdline[0]) {
957 		/* append boot loader cmdline to builtin */
958 		strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);
959 		strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);
960 		strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
961 	}
962 #endif
963 #endif
964 
965 	strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
966 	*cmdline_p = command_line;
967 
968 	/*
969 	 * x86_configure_nx() is called before parse_early_param() to detect
970 	 * whether hardware doesn't support NX (so that the early EHCI debug
971 	 * console setup can safely call set_fixmap()). It may then be called
972 	 * again from within noexec_setup() during parsing early parameters
973 	 * to honor the respective command line option.
974 	 */
975 	x86_configure_nx();
976 
977 	parse_early_param();
978 
979 	x86_report_nx();
980 
981 	/* after early param, so could get panic from serial */
982 	memblock_x86_reserve_range_setup_data();
983 
984 	if (acpi_mps_check()) {
985 #ifdef CONFIG_X86_LOCAL_APIC
986 		disable_apic = 1;
987 #endif
988 		setup_clear_cpu_cap(X86_FEATURE_APIC);
989 	}
990 
991 #ifdef CONFIG_PCI
992 	if (pci_early_dump_regs)
993 		early_dump_pci_devices();
994 #endif
995 
996 	/* update the e820_saved too */
997 	e820_reserve_setup_data();
998 	finish_e820_parsing();
999 
1000 	if (efi_enabled(EFI_BOOT))
1001 		efi_init();
1002 
1003 	dmi_scan_machine();
1004 	dmi_memdev_walk();
1005 	dmi_set_dump_stack_arch_desc();
1006 
1007 	/*
1008 	 * VMware detection requires dmi to be available, so this
1009 	 * needs to be done after dmi_scan_machine, for the BP.
1010 	 */
1011 	init_hypervisor_platform();
1012 
1013 	x86_init.resources.probe_roms();
1014 
1015 	/* after parse_early_param, so could debug it */
1016 	insert_resource(&iomem_resource, &code_resource);
1017 	insert_resource(&iomem_resource, &data_resource);
1018 	insert_resource(&iomem_resource, &bss_resource);
1019 
1020 	e820_add_kernel_range();
1021 	trim_bios_range();
1022 #ifdef CONFIG_X86_32
1023 	if (ppro_with_ram_bug()) {
1024 		e820_update_range(0x70000000ULL, 0x40000ULL, E820_RAM,
1025 				  E820_RESERVED);
1026 		sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
1027 		printk(KERN_INFO "fixed physical RAM map:\n");
1028 		e820_print_map("bad_ppro");
1029 	}
1030 #else
1031 	early_gart_iommu_check();
1032 #endif
1033 
1034 	/*
1035 	 * partially used pages are not usable - thus
1036 	 * we are rounding upwards:
1037 	 */
1038 	max_pfn = e820_end_of_ram_pfn();
1039 
1040 	/* update e820 for memory not covered by WB MTRRs */
1041 	mtrr_bp_init();
1042 	if (mtrr_trim_uncached_memory(max_pfn))
1043 		max_pfn = e820_end_of_ram_pfn();
1044 
1045 #ifdef CONFIG_X86_32
1046 	/* max_low_pfn get updated here */
1047 	find_low_pfn_range();
1048 #else
1049 	check_x2apic();
1050 
1051 	/* How many end-of-memory variables you have, grandma! */
1052 	/* need this before calling reserve_initrd */
1053 	if (max_pfn > (1UL<<(32 - PAGE_SHIFT)))
1054 		max_low_pfn = e820_end_of_low_ram_pfn();
1055 	else
1056 		max_low_pfn = max_pfn;
1057 
1058 	high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
1059 #endif
1060 
1061 	/*
1062 	 * Find and reserve possible boot-time SMP configuration:
1063 	 */
1064 	find_smp_config();
1065 
1066 	reserve_ibft_region();
1067 
1068 	early_alloc_pgt_buf();
1069 
1070 	/*
1071 	 * Need to conclude brk, before memblock_x86_fill()
1072 	 *  it could use memblock_find_in_range, could overlap with
1073 	 *  brk area.
1074 	 */
1075 	reserve_brk();
1076 
1077 	cleanup_highmap();
1078 
1079 	memblock_set_current_limit(ISA_END_ADDRESS);
1080 	memblock_x86_fill();
1081 
1082 	if (efi_enabled(EFI_BOOT))
1083 		efi_find_mirror();
1084 
1085 	/*
1086 	 * The EFI specification says that boot service code won't be called
1087 	 * after ExitBootServices(). This is, in fact, a lie.
1088 	 */
1089 	if (efi_enabled(EFI_MEMMAP))
1090 		efi_reserve_boot_services();
1091 
1092 	/* preallocate 4k for mptable mpc */
1093 	early_reserve_e820_mpc_new();
1094 
1095 #ifdef CONFIG_X86_CHECK_BIOS_CORRUPTION
1096 	setup_bios_corruption_check();
1097 #endif
1098 
1099 #ifdef CONFIG_X86_32
1100 	printk(KERN_DEBUG "initial memory mapped: [mem 0x00000000-%#010lx]\n",
1101 			(max_pfn_mapped<<PAGE_SHIFT) - 1);
1102 #endif
1103 
1104 	reserve_real_mode();
1105 
1106 	trim_platform_memory_ranges();
1107 	trim_low_memory_range();
1108 
1109 	init_mem_mapping();
1110 
1111 	early_trap_pf_init();
1112 
1113 	setup_real_mode();
1114 
1115 	memblock_set_current_limit(get_max_mapped());
1116 
1117 	/*
1118 	 * NOTE: On x86-32, only from this point on, fixmaps are ready for use.
1119 	 */
1120 
1121 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
1122 	if (init_ohci1394_dma_early)
1123 		init_ohci1394_dma_on_all_controllers();
1124 #endif
1125 	/* Allocate bigger log buffer */
1126 	setup_log_buf(1);
1127 
1128 	reserve_initrd();
1129 
1130 #if defined(CONFIG_ACPI) && defined(CONFIG_BLK_DEV_INITRD)
1131 	acpi_initrd_override((void *)initrd_start, initrd_end - initrd_start);
1132 #endif
1133 
1134 	vsmp_init();
1135 
1136 	io_delay_init();
1137 
1138 	/*
1139 	 * Parse the ACPI tables for possible boot-time SMP configuration.
1140 	 */
1141 	acpi_boot_table_init();
1142 
1143 	early_acpi_boot_init();
1144 
1145 	initmem_init();
1146 	dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT);
1147 
1148 	/*
1149 	 * Reserve memory for crash kernel after SRAT is parsed so that it
1150 	 * won't consume hotpluggable memory.
1151 	 */
1152 	reserve_crashkernel();
1153 
1154 	memblock_find_dma_reserve();
1155 
1156 #ifdef CONFIG_KVM_GUEST
1157 	kvmclock_init();
1158 #endif
1159 
1160 	x86_init.paging.pagetable_init();
1161 
1162 	kasan_init();
1163 
1164 	if (boot_cpu_data.cpuid_level >= 0) {
1165 		/* A CPU has %cr4 if and only if it has CPUID */
1166 		mmu_cr4_features = __read_cr4();
1167 		if (trampoline_cr4_features)
1168 			*trampoline_cr4_features = mmu_cr4_features;
1169 	}
1170 
1171 #ifdef CONFIG_X86_32
1172 	/* sync back kernel address range */
1173 	clone_pgd_range(initial_page_table + KERNEL_PGD_BOUNDARY,
1174 			swapper_pg_dir     + KERNEL_PGD_BOUNDARY,
1175 			KERNEL_PGD_PTRS);
1176 
1177 	/*
1178 	 * sync back low identity map too.  It is used for example
1179 	 * in the 32-bit EFI stub.
1180 	 */
1181 	clone_pgd_range(initial_page_table,
1182 			swapper_pg_dir     + KERNEL_PGD_BOUNDARY,
1183 			KERNEL_PGD_PTRS);
1184 #endif
1185 
1186 	tboot_probe();
1187 
1188 	map_vsyscall();
1189 
1190 	generic_apic_probe();
1191 
1192 	early_quirks();
1193 
1194 	/*
1195 	 * Read APIC and some other early information from ACPI tables.
1196 	 */
1197 	acpi_boot_init();
1198 	sfi_init();
1199 	x86_dtb_init();
1200 
1201 	/*
1202 	 * get boot-time SMP configuration:
1203 	 */
1204 	if (smp_found_config)
1205 		get_smp_config();
1206 
1207 	prefill_possible_map();
1208 
1209 	init_cpu_to_node();
1210 
1211 	init_apic_mappings();
1212 	io_apic_init_mappings();
1213 
1214 	kvm_guest_init();
1215 
1216 	e820_reserve_resources();
1217 	e820_mark_nosave_regions(max_low_pfn);
1218 
1219 	x86_init.resources.reserve_resources();
1220 
1221 	e820_setup_gap();
1222 
1223 #ifdef CONFIG_VT
1224 #if defined(CONFIG_VGA_CONSOLE)
1225 	if (!efi_enabled(EFI_BOOT) || (efi_mem_type(0xa0000) != EFI_CONVENTIONAL_MEMORY))
1226 		conswitchp = &vga_con;
1227 #elif defined(CONFIG_DUMMY_CONSOLE)
1228 	conswitchp = &dummy_con;
1229 #endif
1230 #endif
1231 	x86_init.oem.banner();
1232 
1233 	x86_init.timers.wallclock_init();
1234 
1235 	mcheck_init();
1236 
1237 	arch_init_ideal_nops();
1238 
1239 	register_refined_jiffies(CLOCK_TICK_RATE);
1240 
1241 #ifdef CONFIG_EFI
1242 	if (efi_enabled(EFI_BOOT))
1243 		efi_apply_memmap_quirks();
1244 #endif
1245 }
1246 
1247 #ifdef CONFIG_X86_32
1248 
1249 static struct resource video_ram_resource = {
1250 	.name	= "Video RAM area",
1251 	.start	= 0xa0000,
1252 	.end	= 0xbffff,
1253 	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM
1254 };
1255 
1256 void __init i386_reserve_resources(void)
1257 {
1258 	request_resource(&iomem_resource, &video_ram_resource);
1259 	reserve_standard_io_resources();
1260 }
1261 
1262 #endif /* CONFIG_X86_32 */
1263 
1264 static struct notifier_block kernel_offset_notifier = {
1265 	.notifier_call = dump_kernel_offset
1266 };
1267 
1268 static int __init register_kernel_offset_dumper(void)
1269 {
1270 	atomic_notifier_chain_register(&panic_notifier_list,
1271 					&kernel_offset_notifier);
1272 	return 0;
1273 }
1274 __initcall(register_kernel_offset_dumper);
1275