xref: /openbmc/linux/arch/x86/kernel/setup.c (revision 4a075bd4)
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/memblock.h>
34 #include <linux/seq_file.h>
35 #include <linux/console.h>
36 #include <linux/root_dev.h>
37 #include <linux/highmem.h>
38 #include <linux/export.h>
39 #include <linux/efi.h>
40 #include <linux/init.h>
41 #include <linux/edd.h>
42 #include <linux/iscsi_ibft.h>
43 #include <linux/nodemask.h>
44 #include <linux/kexec.h>
45 #include <linux/dmi.h>
46 #include <linux/pfn.h>
47 #include <linux/pci.h>
48 #include <asm/pci-direct.h>
49 #include <linux/init_ohci1394_dma.h>
50 #include <linux/kvm_para.h>
51 #include <linux/dma-contiguous.h>
52 #include <xen/xen.h>
53 #include <uapi/linux/mount.h>
54 
55 #include <linux/errno.h>
56 #include <linux/kernel.h>
57 #include <linux/stddef.h>
58 #include <linux/unistd.h>
59 #include <linux/ptrace.h>
60 #include <linux/user.h>
61 #include <linux/delay.h>
62 
63 #include <linux/kallsyms.h>
64 #include <linux/cpufreq.h>
65 #include <linux/dma-mapping.h>
66 #include <linux/ctype.h>
67 #include <linux/uaccess.h>
68 
69 #include <linux/percpu.h>
70 #include <linux/crash_dump.h>
71 #include <linux/tboot.h>
72 #include <linux/jiffies.h>
73 #include <linux/mem_encrypt.h>
74 #include <linux/sizes.h>
75 
76 #include <linux/usb/xhci-dbgp.h>
77 #include <video/edid.h>
78 
79 #include <asm/mtrr.h>
80 #include <asm/apic.h>
81 #include <asm/realmode.h>
82 #include <asm/e820/api.h>
83 #include <asm/mpspec.h>
84 #include <asm/setup.h>
85 #include <asm/efi.h>
86 #include <asm/timer.h>
87 #include <asm/i8259.h>
88 #include <asm/sections.h>
89 #include <asm/io_apic.h>
90 #include <asm/ist.h>
91 #include <asm/setup_arch.h>
92 #include <asm/bios_ebda.h>
93 #include <asm/cacheflush.h>
94 #include <asm/processor.h>
95 #include <asm/bugs.h>
96 #include <asm/kasan.h>
97 
98 #include <asm/vsyscall.h>
99 #include <asm/cpu.h>
100 #include <asm/desc.h>
101 #include <asm/dma.h>
102 #include <asm/iommu.h>
103 #include <asm/gart.h>
104 #include <asm/mmu_context.h>
105 #include <asm/proto.h>
106 
107 #include <asm/paravirt.h>
108 #include <asm/hypervisor.h>
109 #include <asm/olpc_ofw.h>
110 
111 #include <asm/percpu.h>
112 #include <asm/topology.h>
113 #include <asm/apicdef.h>
114 #include <asm/amd_nb.h>
115 #include <asm/mce.h>
116 #include <asm/alternative.h>
117 #include <asm/prom.h>
118 #include <asm/microcode.h>
119 #include <asm/kaslr.h>
120 #include <asm/unwind.h>
121 
122 /*
123  * max_low_pfn_mapped: highest direct mapped pfn under 4GB
124  * max_pfn_mapped:     highest direct mapped pfn over 4GB
125  *
126  * The direct mapping only covers E820_TYPE_RAM regions, so the ranges and gaps are
127  * represented by pfn_mapped
128  */
129 unsigned long max_low_pfn_mapped;
130 unsigned long max_pfn_mapped;
131 
132 #ifdef CONFIG_DMI
133 RESERVE_BRK(dmi_alloc, 65536);
134 #endif
135 
136 
137 static __initdata unsigned long _brk_start = (unsigned long)__brk_base;
138 unsigned long _brk_end = (unsigned long)__brk_base;
139 
140 struct boot_params boot_params;
141 
142 /*
143  * Machine setup..
144  */
145 static struct resource data_resource = {
146 	.name	= "Kernel data",
147 	.start	= 0,
148 	.end	= 0,
149 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
150 };
151 
152 static struct resource code_resource = {
153 	.name	= "Kernel code",
154 	.start	= 0,
155 	.end	= 0,
156 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
157 };
158 
159 static struct resource bss_resource = {
160 	.name	= "Kernel bss",
161 	.start	= 0,
162 	.end	= 0,
163 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
164 };
165 
166 
167 #ifdef CONFIG_X86_32
168 /* cpu data as detected by the assembly code in head_32.S */
169 struct cpuinfo_x86 new_cpu_data;
170 
171 /* common cpu data for all cpus */
172 struct cpuinfo_x86 boot_cpu_data __read_mostly;
173 EXPORT_SYMBOL(boot_cpu_data);
174 
175 unsigned int def_to_bigsmp;
176 
177 /* for MCA, but anyone else can use it if they want */
178 unsigned int machine_id;
179 unsigned int machine_submodel_id;
180 unsigned int BIOS_revision;
181 
182 struct apm_info apm_info;
183 EXPORT_SYMBOL(apm_info);
184 
185 #if defined(CONFIG_X86_SPEEDSTEP_SMI) || \
186 	defined(CONFIG_X86_SPEEDSTEP_SMI_MODULE)
187 struct ist_info ist_info;
188 EXPORT_SYMBOL(ist_info);
189 #else
190 struct ist_info ist_info;
191 #endif
192 
193 #else
194 struct cpuinfo_x86 boot_cpu_data __read_mostly;
195 EXPORT_SYMBOL(boot_cpu_data);
196 #endif
197 
198 
199 #if !defined(CONFIG_X86_PAE) || defined(CONFIG_X86_64)
200 __visible unsigned long mmu_cr4_features __ro_after_init;
201 #else
202 __visible unsigned long mmu_cr4_features __ro_after_init = X86_CR4_PAE;
203 #endif
204 
205 /* Boot loader ID and version as integers, for the benefit of proc_dointvec */
206 int bootloader_type, bootloader_version;
207 
208 /*
209  * Setup options
210  */
211 struct screen_info screen_info;
212 EXPORT_SYMBOL(screen_info);
213 struct edid_info edid_info;
214 EXPORT_SYMBOL_GPL(edid_info);
215 
216 extern int root_mountflags;
217 
218 unsigned long saved_video_mode;
219 
220 #define RAMDISK_IMAGE_START_MASK	0x07FF
221 #define RAMDISK_PROMPT_FLAG		0x8000
222 #define RAMDISK_LOAD_FLAG		0x4000
223 
224 static char __initdata command_line[COMMAND_LINE_SIZE];
225 #ifdef CONFIG_CMDLINE_BOOL
226 static char __initdata builtin_cmdline[COMMAND_LINE_SIZE] = CONFIG_CMDLINE;
227 #endif
228 
229 #if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
230 struct edd edd;
231 #ifdef CONFIG_EDD_MODULE
232 EXPORT_SYMBOL(edd);
233 #endif
234 /**
235  * copy_edd() - Copy the BIOS EDD information
236  *              from boot_params into a safe place.
237  *
238  */
239 static inline void __init copy_edd(void)
240 {
241      memcpy(edd.mbr_signature, boot_params.edd_mbr_sig_buffer,
242 	    sizeof(edd.mbr_signature));
243      memcpy(edd.edd_info, boot_params.eddbuf, sizeof(edd.edd_info));
244      edd.mbr_signature_nr = boot_params.edd_mbr_sig_buf_entries;
245      edd.edd_info_nr = boot_params.eddbuf_entries;
246 }
247 #else
248 static inline void __init copy_edd(void)
249 {
250 }
251 #endif
252 
253 void * __init extend_brk(size_t size, size_t align)
254 {
255 	size_t mask = align - 1;
256 	void *ret;
257 
258 	BUG_ON(_brk_start == 0);
259 	BUG_ON(align & mask);
260 
261 	_brk_end = (_brk_end + mask) & ~mask;
262 	BUG_ON((char *)(_brk_end + size) > __brk_limit);
263 
264 	ret = (void *)_brk_end;
265 	_brk_end += size;
266 
267 	memset(ret, 0, size);
268 
269 	return ret;
270 }
271 
272 #ifdef CONFIG_X86_32
273 static void __init cleanup_highmap(void)
274 {
275 }
276 #endif
277 
278 static void __init reserve_brk(void)
279 {
280 	if (_brk_end > _brk_start)
281 		memblock_reserve(__pa_symbol(_brk_start),
282 				 _brk_end - _brk_start);
283 
284 	/* Mark brk area as locked down and no longer taking any
285 	   new allocations */
286 	_brk_start = 0;
287 }
288 
289 u64 relocated_ramdisk;
290 
291 #ifdef CONFIG_BLK_DEV_INITRD
292 
293 static u64 __init get_ramdisk_image(void)
294 {
295 	u64 ramdisk_image = boot_params.hdr.ramdisk_image;
296 
297 	ramdisk_image |= (u64)boot_params.ext_ramdisk_image << 32;
298 
299 	return ramdisk_image;
300 }
301 static u64 __init get_ramdisk_size(void)
302 {
303 	u64 ramdisk_size = boot_params.hdr.ramdisk_size;
304 
305 	ramdisk_size |= (u64)boot_params.ext_ramdisk_size << 32;
306 
307 	return ramdisk_size;
308 }
309 
310 static void __init relocate_initrd(void)
311 {
312 	/* Assume only end is not page aligned */
313 	u64 ramdisk_image = get_ramdisk_image();
314 	u64 ramdisk_size  = get_ramdisk_size();
315 	u64 area_size     = PAGE_ALIGN(ramdisk_size);
316 
317 	/* We need to move the initrd down into directly mapped mem */
318 	relocated_ramdisk = memblock_find_in_range(0, PFN_PHYS(max_pfn_mapped),
319 						   area_size, PAGE_SIZE);
320 
321 	if (!relocated_ramdisk)
322 		panic("Cannot find place for new RAMDISK of size %lld\n",
323 		      ramdisk_size);
324 
325 	/* Note: this includes all the mem currently occupied by
326 	   the initrd, we rely on that fact to keep the data intact. */
327 	memblock_reserve(relocated_ramdisk, area_size);
328 	initrd_start = relocated_ramdisk + PAGE_OFFSET;
329 	initrd_end   = initrd_start + ramdisk_size;
330 	printk(KERN_INFO "Allocated new RAMDISK: [mem %#010llx-%#010llx]\n",
331 	       relocated_ramdisk, relocated_ramdisk + ramdisk_size - 1);
332 
333 	copy_from_early_mem((void *)initrd_start, ramdisk_image, ramdisk_size);
334 
335 	printk(KERN_INFO "Move RAMDISK from [mem %#010llx-%#010llx] to"
336 		" [mem %#010llx-%#010llx]\n",
337 		ramdisk_image, ramdisk_image + ramdisk_size - 1,
338 		relocated_ramdisk, relocated_ramdisk + ramdisk_size - 1);
339 }
340 
341 static void __init early_reserve_initrd(void)
342 {
343 	/* Assume only end is not page aligned */
344 	u64 ramdisk_image = get_ramdisk_image();
345 	u64 ramdisk_size  = get_ramdisk_size();
346 	u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
347 
348 	if (!boot_params.hdr.type_of_loader ||
349 	    !ramdisk_image || !ramdisk_size)
350 		return;		/* No initrd provided by bootloader */
351 
352 	memblock_reserve(ramdisk_image, ramdisk_end - ramdisk_image);
353 }
354 static void __init reserve_initrd(void)
355 {
356 	/* Assume only end is not page aligned */
357 	u64 ramdisk_image = get_ramdisk_image();
358 	u64 ramdisk_size  = get_ramdisk_size();
359 	u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
360 	u64 mapped_size;
361 
362 	if (!boot_params.hdr.type_of_loader ||
363 	    !ramdisk_image || !ramdisk_size)
364 		return;		/* No initrd provided by bootloader */
365 
366 	initrd_start = 0;
367 
368 	mapped_size = memblock_mem_size(max_pfn_mapped);
369 	if (ramdisk_size >= (mapped_size>>1))
370 		panic("initrd too large to handle, "
371 		       "disabling initrd (%lld needed, %lld available)\n",
372 		       ramdisk_size, mapped_size>>1);
373 
374 	printk(KERN_INFO "RAMDISK: [mem %#010llx-%#010llx]\n", ramdisk_image,
375 			ramdisk_end - 1);
376 
377 	if (pfn_range_is_mapped(PFN_DOWN(ramdisk_image),
378 				PFN_DOWN(ramdisk_end))) {
379 		/* All are mapped, easy case */
380 		initrd_start = ramdisk_image + PAGE_OFFSET;
381 		initrd_end = initrd_start + ramdisk_size;
382 		return;
383 	}
384 
385 	relocate_initrd();
386 
387 	memblock_free(ramdisk_image, ramdisk_end - ramdisk_image);
388 }
389 
390 #else
391 static void __init early_reserve_initrd(void)
392 {
393 }
394 static void __init reserve_initrd(void)
395 {
396 }
397 #endif /* CONFIG_BLK_DEV_INITRD */
398 
399 static void __init parse_setup_data(void)
400 {
401 	struct setup_data *data;
402 	u64 pa_data, pa_next;
403 
404 	pa_data = boot_params.hdr.setup_data;
405 	while (pa_data) {
406 		u32 data_len, data_type;
407 
408 		data = early_memremap(pa_data, sizeof(*data));
409 		data_len = data->len + sizeof(struct setup_data);
410 		data_type = data->type;
411 		pa_next = data->next;
412 		early_memunmap(data, sizeof(*data));
413 
414 		switch (data_type) {
415 		case SETUP_E820_EXT:
416 			e820__memory_setup_extended(pa_data, data_len);
417 			break;
418 		case SETUP_DTB:
419 			add_dtb(pa_data);
420 			break;
421 		case SETUP_EFI:
422 			parse_efi_setup(pa_data, data_len);
423 			break;
424 		default:
425 			break;
426 		}
427 		pa_data = pa_next;
428 	}
429 }
430 
431 static void __init memblock_x86_reserve_range_setup_data(void)
432 {
433 	struct setup_data *data;
434 	u64 pa_data;
435 
436 	pa_data = boot_params.hdr.setup_data;
437 	while (pa_data) {
438 		data = early_memremap(pa_data, sizeof(*data));
439 		memblock_reserve(pa_data, sizeof(*data) + data->len);
440 		pa_data = data->next;
441 		early_memunmap(data, sizeof(*data));
442 	}
443 }
444 
445 /*
446  * --------- Crashkernel reservation ------------------------------
447  */
448 
449 #ifdef CONFIG_KEXEC_CORE
450 
451 /* 16M alignment for crash kernel regions */
452 #define CRASH_ALIGN		SZ_16M
453 
454 /*
455  * Keep the crash kernel below this limit.  On 32 bits earlier kernels
456  * would limit the kernel to the low 512 MiB due to mapping restrictions.
457  */
458 #ifdef CONFIG_X86_32
459 # define CRASH_ADDR_LOW_MAX	SZ_512M
460 # define CRASH_ADDR_HIGH_MAX	SZ_512M
461 #else
462 # define CRASH_ADDR_LOW_MAX	SZ_4G
463 # define CRASH_ADDR_HIGH_MAX	MAXMEM
464 #endif
465 
466 static int __init reserve_crashkernel_low(void)
467 {
468 #ifdef CONFIG_X86_64
469 	unsigned long long base, low_base = 0, low_size = 0;
470 	unsigned long total_low_mem;
471 	int ret;
472 
473 	total_low_mem = memblock_mem_size(1UL << (32 - PAGE_SHIFT));
474 
475 	/* crashkernel=Y,low */
476 	ret = parse_crashkernel_low(boot_command_line, total_low_mem, &low_size, &base);
477 	if (ret) {
478 		/*
479 		 * two parts from lib/swiotlb.c:
480 		 * -swiotlb size: user-specified with swiotlb= or default.
481 		 *
482 		 * -swiotlb overflow buffer: now hardcoded to 32k. We round it
483 		 * to 8M for other buffers that may need to stay low too. Also
484 		 * make sure we allocate enough extra low memory so that we
485 		 * don't run out of DMA buffers for 32-bit devices.
486 		 */
487 		low_size = max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20);
488 	} else {
489 		/* passed with crashkernel=0,low ? */
490 		if (!low_size)
491 			return 0;
492 	}
493 
494 	low_base = memblock_find_in_range(0, 1ULL << 32, low_size, CRASH_ALIGN);
495 	if (!low_base) {
496 		pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n",
497 		       (unsigned long)(low_size >> 20));
498 		return -ENOMEM;
499 	}
500 
501 	ret = memblock_reserve(low_base, low_size);
502 	if (ret) {
503 		pr_err("%s: Error reserving crashkernel low memblock.\n", __func__);
504 		return ret;
505 	}
506 
507 	pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (System low RAM: %ldMB)\n",
508 		(unsigned long)(low_size >> 20),
509 		(unsigned long)(low_base >> 20),
510 		(unsigned long)(total_low_mem >> 20));
511 
512 	crashk_low_res.start = low_base;
513 	crashk_low_res.end   = low_base + low_size - 1;
514 	insert_resource(&iomem_resource, &crashk_low_res);
515 #endif
516 	return 0;
517 }
518 
519 static void __init reserve_crashkernel(void)
520 {
521 	unsigned long long crash_size, crash_base, total_mem;
522 	bool high = false;
523 	int ret;
524 
525 	total_mem = memblock_phys_mem_size();
526 
527 	/* crashkernel=XM */
528 	ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base);
529 	if (ret != 0 || crash_size <= 0) {
530 		/* crashkernel=X,high */
531 		ret = parse_crashkernel_high(boot_command_line, total_mem,
532 					     &crash_size, &crash_base);
533 		if (ret != 0 || crash_size <= 0)
534 			return;
535 		high = true;
536 	}
537 
538 	if (xen_pv_domain()) {
539 		pr_info("Ignoring crashkernel for a Xen PV domain\n");
540 		return;
541 	}
542 
543 	/* 0 means: find the address automatically */
544 	if (!crash_base) {
545 		/*
546 		 * Set CRASH_ADDR_LOW_MAX upper bound for crash memory,
547 		 * crashkernel=x,high reserves memory over 4G, also allocates
548 		 * 256M extra low memory for DMA buffers and swiotlb.
549 		 * But the extra memory is not required for all machines.
550 		 * So try low memory first and fall back to high memory
551 		 * unless "crashkernel=size[KMG],high" is specified.
552 		 */
553 		if (!high)
554 			crash_base = memblock_find_in_range(CRASH_ALIGN,
555 						CRASH_ADDR_LOW_MAX,
556 						crash_size, CRASH_ALIGN);
557 		if (!crash_base)
558 			crash_base = memblock_find_in_range(CRASH_ALIGN,
559 						CRASH_ADDR_HIGH_MAX,
560 						crash_size, CRASH_ALIGN);
561 		if (!crash_base) {
562 			pr_info("crashkernel reservation failed - No suitable area found.\n");
563 			return;
564 		}
565 	} else {
566 		unsigned long long start;
567 
568 		start = memblock_find_in_range(crash_base,
569 					       crash_base + crash_size,
570 					       crash_size, 1 << 20);
571 		if (start != crash_base) {
572 			pr_info("crashkernel reservation failed - memory is in use.\n");
573 			return;
574 		}
575 	}
576 	ret = memblock_reserve(crash_base, crash_size);
577 	if (ret) {
578 		pr_err("%s: Error reserving crashkernel memblock.\n", __func__);
579 		return;
580 	}
581 
582 	if (crash_base >= (1ULL << 32) && reserve_crashkernel_low()) {
583 		memblock_free(crash_base, crash_size);
584 		return;
585 	}
586 
587 	pr_info("Reserving %ldMB of memory at %ldMB for crashkernel (System RAM: %ldMB)\n",
588 		(unsigned long)(crash_size >> 20),
589 		(unsigned long)(crash_base >> 20),
590 		(unsigned long)(total_mem >> 20));
591 
592 	crashk_res.start = crash_base;
593 	crashk_res.end   = crash_base + crash_size - 1;
594 	insert_resource(&iomem_resource, &crashk_res);
595 }
596 #else
597 static void __init reserve_crashkernel(void)
598 {
599 }
600 #endif
601 
602 static struct resource standard_io_resources[] = {
603 	{ .name = "dma1", .start = 0x00, .end = 0x1f,
604 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
605 	{ .name = "pic1", .start = 0x20, .end = 0x21,
606 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
607 	{ .name = "timer0", .start = 0x40, .end = 0x43,
608 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
609 	{ .name = "timer1", .start = 0x50, .end = 0x53,
610 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
611 	{ .name = "keyboard", .start = 0x60, .end = 0x60,
612 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
613 	{ .name = "keyboard", .start = 0x64, .end = 0x64,
614 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
615 	{ .name = "dma page reg", .start = 0x80, .end = 0x8f,
616 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
617 	{ .name = "pic2", .start = 0xa0, .end = 0xa1,
618 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
619 	{ .name = "dma2", .start = 0xc0, .end = 0xdf,
620 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
621 	{ .name = "fpu", .start = 0xf0, .end = 0xff,
622 		.flags = IORESOURCE_BUSY | IORESOURCE_IO }
623 };
624 
625 void __init reserve_standard_io_resources(void)
626 {
627 	int i;
628 
629 	/* request I/O space for devices used on all i[345]86 PCs */
630 	for (i = 0; i < ARRAY_SIZE(standard_io_resources); i++)
631 		request_resource(&ioport_resource, &standard_io_resources[i]);
632 
633 }
634 
635 static __init void reserve_ibft_region(void)
636 {
637 	unsigned long addr, size = 0;
638 
639 	addr = find_ibft_region(&size);
640 
641 	if (size)
642 		memblock_reserve(addr, size);
643 }
644 
645 static bool __init snb_gfx_workaround_needed(void)
646 {
647 #ifdef CONFIG_PCI
648 	int i;
649 	u16 vendor, devid;
650 	static const __initconst u16 snb_ids[] = {
651 		0x0102,
652 		0x0112,
653 		0x0122,
654 		0x0106,
655 		0x0116,
656 		0x0126,
657 		0x010a,
658 	};
659 
660 	/* Assume no if something weird is going on with PCI */
661 	if (!early_pci_allowed())
662 		return false;
663 
664 	vendor = read_pci_config_16(0, 2, 0, PCI_VENDOR_ID);
665 	if (vendor != 0x8086)
666 		return false;
667 
668 	devid = read_pci_config_16(0, 2, 0, PCI_DEVICE_ID);
669 	for (i = 0; i < ARRAY_SIZE(snb_ids); i++)
670 		if (devid == snb_ids[i])
671 			return true;
672 #endif
673 
674 	return false;
675 }
676 
677 /*
678  * Sandy Bridge graphics has trouble with certain ranges, exclude
679  * them from allocation.
680  */
681 static void __init trim_snb_memory(void)
682 {
683 	static const __initconst unsigned long bad_pages[] = {
684 		0x20050000,
685 		0x20110000,
686 		0x20130000,
687 		0x20138000,
688 		0x40004000,
689 	};
690 	int i;
691 
692 	if (!snb_gfx_workaround_needed())
693 		return;
694 
695 	printk(KERN_DEBUG "reserving inaccessible SNB gfx pages\n");
696 
697 	/*
698 	 * Reserve all memory below the 1 MB mark that has not
699 	 * already been reserved.
700 	 */
701 	memblock_reserve(0, 1<<20);
702 
703 	for (i = 0; i < ARRAY_SIZE(bad_pages); i++) {
704 		if (memblock_reserve(bad_pages[i], PAGE_SIZE))
705 			printk(KERN_WARNING "failed to reserve 0x%08lx\n",
706 			       bad_pages[i]);
707 	}
708 }
709 
710 /*
711  * Here we put platform-specific memory range workarounds, i.e.
712  * memory known to be corrupt or otherwise in need to be reserved on
713  * specific platforms.
714  *
715  * If this gets used more widely it could use a real dispatch mechanism.
716  */
717 static void __init trim_platform_memory_ranges(void)
718 {
719 	trim_snb_memory();
720 }
721 
722 static void __init trim_bios_range(void)
723 {
724 	/*
725 	 * A special case is the first 4Kb of memory;
726 	 * This is a BIOS owned area, not kernel ram, but generally
727 	 * not listed as such in the E820 table.
728 	 *
729 	 * This typically reserves additional memory (64KiB by default)
730 	 * since some BIOSes are known to corrupt low memory.  See the
731 	 * Kconfig help text for X86_RESERVE_LOW.
732 	 */
733 	e820__range_update(0, PAGE_SIZE, E820_TYPE_RAM, E820_TYPE_RESERVED);
734 
735 	/*
736 	 * special case: Some BIOSen report the PC BIOS
737 	 * area (640->1Mb) as ram even though it is not.
738 	 * take them out.
739 	 */
740 	e820__range_remove(BIOS_BEGIN, BIOS_END - BIOS_BEGIN, E820_TYPE_RAM, 1);
741 
742 	e820__update_table(e820_table);
743 }
744 
745 /* called before trim_bios_range() to spare extra sanitize */
746 static void __init e820_add_kernel_range(void)
747 {
748 	u64 start = __pa_symbol(_text);
749 	u64 size = __pa_symbol(_end) - start;
750 
751 	/*
752 	 * Complain if .text .data and .bss are not marked as E820_TYPE_RAM and
753 	 * attempt to fix it by adding the range. We may have a confused BIOS,
754 	 * or the user may have used memmap=exactmap or memmap=xxM$yyM to
755 	 * exclude kernel range. If we really are running on top non-RAM,
756 	 * we will crash later anyways.
757 	 */
758 	if (e820__mapped_all(start, start + size, E820_TYPE_RAM))
759 		return;
760 
761 	pr_warn(".text .data .bss are not marked as E820_TYPE_RAM!\n");
762 	e820__range_remove(start, size, E820_TYPE_RAM, 0);
763 	e820__range_add(start, size, E820_TYPE_RAM);
764 }
765 
766 static unsigned reserve_low = CONFIG_X86_RESERVE_LOW << 10;
767 
768 static int __init parse_reservelow(char *p)
769 {
770 	unsigned long long size;
771 
772 	if (!p)
773 		return -EINVAL;
774 
775 	size = memparse(p, &p);
776 
777 	if (size < 4096)
778 		size = 4096;
779 
780 	if (size > 640*1024)
781 		size = 640*1024;
782 
783 	reserve_low = size;
784 
785 	return 0;
786 }
787 
788 early_param("reservelow", parse_reservelow);
789 
790 static void __init trim_low_memory_range(void)
791 {
792 	memblock_reserve(0, ALIGN(reserve_low, PAGE_SIZE));
793 }
794 
795 /*
796  * Dump out kernel offset information on panic.
797  */
798 static int
799 dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
800 {
801 	if (kaslr_enabled()) {
802 		pr_emerg("Kernel Offset: 0x%lx from 0x%lx (relocation range: 0x%lx-0x%lx)\n",
803 			 kaslr_offset(),
804 			 __START_KERNEL,
805 			 __START_KERNEL_map,
806 			 MODULES_VADDR-1);
807 	} else {
808 		pr_emerg("Kernel Offset: disabled\n");
809 	}
810 
811 	return 0;
812 }
813 
814 /*
815  * Determine if we were loaded by an EFI loader.  If so, then we have also been
816  * passed the efi memmap, systab, etc., so we should use these data structures
817  * for initialization.  Note, the efi init code path is determined by the
818  * global efi_enabled. This allows the same kernel image to be used on existing
819  * systems (with a traditional BIOS) as well as on EFI systems.
820  */
821 /*
822  * setup_arch - architecture-specific boot-time initializations
823  *
824  * Note: On x86_64, fixmaps are ready for use even before this is called.
825  */
826 
827 void __init setup_arch(char **cmdline_p)
828 {
829 	memblock_reserve(__pa_symbol(_text),
830 			 (unsigned long)__bss_stop - (unsigned long)_text);
831 
832 	/*
833 	 * Make sure page 0 is always reserved because on systems with
834 	 * L1TF its contents can be leaked to user processes.
835 	 */
836 	memblock_reserve(0, PAGE_SIZE);
837 
838 	early_reserve_initrd();
839 
840 	/*
841 	 * At this point everything still needed from the boot loader
842 	 * or BIOS or kernel text should be early reserved or marked not
843 	 * RAM in e820. All other memory is free game.
844 	 */
845 
846 #ifdef CONFIG_X86_32
847 	memcpy(&boot_cpu_data, &new_cpu_data, sizeof(new_cpu_data));
848 
849 	/*
850 	 * copy kernel address range established so far and switch
851 	 * to the proper swapper page table
852 	 */
853 	clone_pgd_range(swapper_pg_dir     + KERNEL_PGD_BOUNDARY,
854 			initial_page_table + KERNEL_PGD_BOUNDARY,
855 			KERNEL_PGD_PTRS);
856 
857 	load_cr3(swapper_pg_dir);
858 	/*
859 	 * Note: Quark X1000 CPUs advertise PGE incorrectly and require
860 	 * a cr3 based tlb flush, so the following __flush_tlb_all()
861 	 * will not flush anything because the cpu quirk which clears
862 	 * X86_FEATURE_PGE has not been invoked yet. Though due to the
863 	 * load_cr3() above the TLB has been flushed already. The
864 	 * quirk is invoked before subsequent calls to __flush_tlb_all()
865 	 * so proper operation is guaranteed.
866 	 */
867 	__flush_tlb_all();
868 #else
869 	printk(KERN_INFO "Command line: %s\n", boot_command_line);
870 	boot_cpu_data.x86_phys_bits = MAX_PHYSMEM_BITS;
871 #endif
872 
873 	/*
874 	 * If we have OLPC OFW, we might end up relocating the fixmap due to
875 	 * reserve_top(), so do this before touching the ioremap area.
876 	 */
877 	olpc_ofw_detect();
878 
879 	idt_setup_early_traps();
880 	early_cpu_init();
881 	arch_init_ideal_nops();
882 	jump_label_init();
883 	early_ioremap_init();
884 
885 	setup_olpc_ofw_pgd();
886 
887 	ROOT_DEV = old_decode_dev(boot_params.hdr.root_dev);
888 	screen_info = boot_params.screen_info;
889 	edid_info = boot_params.edid_info;
890 #ifdef CONFIG_X86_32
891 	apm_info.bios = boot_params.apm_bios_info;
892 	ist_info = boot_params.ist_info;
893 #endif
894 	saved_video_mode = boot_params.hdr.vid_mode;
895 	bootloader_type = boot_params.hdr.type_of_loader;
896 	if ((bootloader_type >> 4) == 0xe) {
897 		bootloader_type &= 0xf;
898 		bootloader_type |= (boot_params.hdr.ext_loader_type+0x10) << 4;
899 	}
900 	bootloader_version  = bootloader_type & 0xf;
901 	bootloader_version |= boot_params.hdr.ext_loader_ver << 4;
902 
903 #ifdef CONFIG_BLK_DEV_RAM
904 	rd_image_start = boot_params.hdr.ram_size & RAMDISK_IMAGE_START_MASK;
905 	rd_prompt = ((boot_params.hdr.ram_size & RAMDISK_PROMPT_FLAG) != 0);
906 	rd_doload = ((boot_params.hdr.ram_size & RAMDISK_LOAD_FLAG) != 0);
907 #endif
908 #ifdef CONFIG_EFI
909 	if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
910 		     EFI32_LOADER_SIGNATURE, 4)) {
911 		set_bit(EFI_BOOT, &efi.flags);
912 	} else if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
913 		     EFI64_LOADER_SIGNATURE, 4)) {
914 		set_bit(EFI_BOOT, &efi.flags);
915 		set_bit(EFI_64BIT, &efi.flags);
916 	}
917 #endif
918 
919 	x86_init.oem.arch_setup();
920 
921 	iomem_resource.end = (1ULL << boot_cpu_data.x86_phys_bits) - 1;
922 	e820__memory_setup();
923 	parse_setup_data();
924 
925 	copy_edd();
926 
927 	if (!boot_params.hdr.root_flags)
928 		root_mountflags &= ~MS_RDONLY;
929 	init_mm.start_code = (unsigned long) _text;
930 	init_mm.end_code = (unsigned long) _etext;
931 	init_mm.end_data = (unsigned long) _edata;
932 	init_mm.brk = _brk_end;
933 
934 	mpx_mm_init(&init_mm);
935 
936 	code_resource.start = __pa_symbol(_text);
937 	code_resource.end = __pa_symbol(_etext)-1;
938 	data_resource.start = __pa_symbol(_etext);
939 	data_resource.end = __pa_symbol(_edata)-1;
940 	bss_resource.start = __pa_symbol(__bss_start);
941 	bss_resource.end = __pa_symbol(__bss_stop)-1;
942 
943 #ifdef CONFIG_CMDLINE_BOOL
944 #ifdef CONFIG_CMDLINE_OVERRIDE
945 	strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
946 #else
947 	if (builtin_cmdline[0]) {
948 		/* append boot loader cmdline to builtin */
949 		strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);
950 		strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);
951 		strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
952 	}
953 #endif
954 #endif
955 
956 	strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
957 	*cmdline_p = command_line;
958 
959 	/*
960 	 * x86_configure_nx() is called before parse_early_param() to detect
961 	 * whether hardware doesn't support NX (so that the early EHCI debug
962 	 * console setup can safely call set_fixmap()). It may then be called
963 	 * again from within noexec_setup() during parsing early parameters
964 	 * to honor the respective command line option.
965 	 */
966 	x86_configure_nx();
967 
968 	parse_early_param();
969 
970 	if (efi_enabled(EFI_BOOT))
971 		efi_memblock_x86_reserve_range();
972 #ifdef CONFIG_MEMORY_HOTPLUG
973 	/*
974 	 * Memory used by the kernel cannot be hot-removed because Linux
975 	 * cannot migrate the kernel pages. When memory hotplug is
976 	 * enabled, we should prevent memblock from allocating memory
977 	 * for the kernel.
978 	 *
979 	 * ACPI SRAT records all hotpluggable memory ranges. But before
980 	 * SRAT is parsed, we don't know about it.
981 	 *
982 	 * The kernel image is loaded into memory at very early time. We
983 	 * cannot prevent this anyway. So on NUMA system, we set any
984 	 * node the kernel resides in as un-hotpluggable.
985 	 *
986 	 * Since on modern servers, one node could have double-digit
987 	 * gigabytes memory, we can assume the memory around the kernel
988 	 * image is also un-hotpluggable. So before SRAT is parsed, just
989 	 * allocate memory near the kernel image to try the best to keep
990 	 * the kernel away from hotpluggable memory.
991 	 */
992 	if (movable_node_is_enabled())
993 		memblock_set_bottom_up(true);
994 #endif
995 
996 	x86_report_nx();
997 
998 	/* after early param, so could get panic from serial */
999 	memblock_x86_reserve_range_setup_data();
1000 
1001 	if (acpi_mps_check()) {
1002 #ifdef CONFIG_X86_LOCAL_APIC
1003 		disable_apic = 1;
1004 #endif
1005 		setup_clear_cpu_cap(X86_FEATURE_APIC);
1006 	}
1007 
1008 	e820__reserve_setup_data();
1009 	e820__finish_early_params();
1010 
1011 	if (efi_enabled(EFI_BOOT))
1012 		efi_init();
1013 
1014 	dmi_setup();
1015 
1016 	/*
1017 	 * VMware detection requires dmi to be available, so this
1018 	 * needs to be done after dmi_setup(), for the boot CPU.
1019 	 */
1020 	init_hypervisor_platform();
1021 
1022 	tsc_early_init();
1023 	x86_init.resources.probe_roms();
1024 
1025 	/* after parse_early_param, so could debug it */
1026 	insert_resource(&iomem_resource, &code_resource);
1027 	insert_resource(&iomem_resource, &data_resource);
1028 	insert_resource(&iomem_resource, &bss_resource);
1029 
1030 	e820_add_kernel_range();
1031 	trim_bios_range();
1032 #ifdef CONFIG_X86_32
1033 	if (ppro_with_ram_bug()) {
1034 		e820__range_update(0x70000000ULL, 0x40000ULL, E820_TYPE_RAM,
1035 				  E820_TYPE_RESERVED);
1036 		e820__update_table(e820_table);
1037 		printk(KERN_INFO "fixed physical RAM map:\n");
1038 		e820__print_table("bad_ppro");
1039 	}
1040 #else
1041 	early_gart_iommu_check();
1042 #endif
1043 
1044 	/*
1045 	 * partially used pages are not usable - thus
1046 	 * we are rounding upwards:
1047 	 */
1048 	max_pfn = e820__end_of_ram_pfn();
1049 
1050 	/* update e820 for memory not covered by WB MTRRs */
1051 	mtrr_bp_init();
1052 	if (mtrr_trim_uncached_memory(max_pfn))
1053 		max_pfn = e820__end_of_ram_pfn();
1054 
1055 	max_possible_pfn = max_pfn;
1056 
1057 	/*
1058 	 * This call is required when the CPU does not support PAT. If
1059 	 * mtrr_bp_init() invoked it already via pat_init() the call has no
1060 	 * effect.
1061 	 */
1062 	init_cache_modes();
1063 
1064 	/*
1065 	 * Define random base addresses for memory sections after max_pfn is
1066 	 * defined and before each memory section base is used.
1067 	 */
1068 	kernel_randomize_memory();
1069 
1070 #ifdef CONFIG_X86_32
1071 	/* max_low_pfn get updated here */
1072 	find_low_pfn_range();
1073 #else
1074 	check_x2apic();
1075 
1076 	/* How many end-of-memory variables you have, grandma! */
1077 	/* need this before calling reserve_initrd */
1078 	if (max_pfn > (1UL<<(32 - PAGE_SHIFT)))
1079 		max_low_pfn = e820__end_of_low_ram_pfn();
1080 	else
1081 		max_low_pfn = max_pfn;
1082 
1083 	high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
1084 #endif
1085 
1086 	/*
1087 	 * Find and reserve possible boot-time SMP configuration:
1088 	 */
1089 	find_smp_config();
1090 
1091 	reserve_ibft_region();
1092 
1093 	early_alloc_pgt_buf();
1094 
1095 	/*
1096 	 * Need to conclude brk, before e820__memblock_setup()
1097 	 *  it could use memblock_find_in_range, could overlap with
1098 	 *  brk area.
1099 	 */
1100 	reserve_brk();
1101 
1102 	cleanup_highmap();
1103 
1104 	memblock_set_current_limit(ISA_END_ADDRESS);
1105 	e820__memblock_setup();
1106 
1107 	reserve_bios_regions();
1108 
1109 	if (efi_enabled(EFI_MEMMAP)) {
1110 		efi_fake_memmap();
1111 		efi_find_mirror();
1112 		efi_esrt_init();
1113 
1114 		/*
1115 		 * The EFI specification says that boot service code won't be
1116 		 * called after ExitBootServices(). This is, in fact, a lie.
1117 		 */
1118 		efi_reserve_boot_services();
1119 	}
1120 
1121 	/* preallocate 4k for mptable mpc */
1122 	e820__memblock_alloc_reserved_mpc_new();
1123 
1124 #ifdef CONFIG_X86_CHECK_BIOS_CORRUPTION
1125 	setup_bios_corruption_check();
1126 #endif
1127 
1128 #ifdef CONFIG_X86_32
1129 	printk(KERN_DEBUG "initial memory mapped: [mem 0x00000000-%#010lx]\n",
1130 			(max_pfn_mapped<<PAGE_SHIFT) - 1);
1131 #endif
1132 
1133 	reserve_real_mode();
1134 
1135 	trim_platform_memory_ranges();
1136 	trim_low_memory_range();
1137 
1138 	init_mem_mapping();
1139 
1140 	idt_setup_early_pf();
1141 
1142 	/*
1143 	 * Update mmu_cr4_features (and, indirectly, trampoline_cr4_features)
1144 	 * with the current CR4 value.  This may not be necessary, but
1145 	 * auditing all the early-boot CR4 manipulation would be needed to
1146 	 * rule it out.
1147 	 *
1148 	 * Mask off features that don't work outside long mode (just
1149 	 * PCIDE for now).
1150 	 */
1151 	mmu_cr4_features = __read_cr4() & ~X86_CR4_PCIDE;
1152 
1153 	memblock_set_current_limit(get_max_mapped());
1154 
1155 	/*
1156 	 * NOTE: On x86-32, only from this point on, fixmaps are ready for use.
1157 	 */
1158 
1159 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
1160 	if (init_ohci1394_dma_early)
1161 		init_ohci1394_dma_on_all_controllers();
1162 #endif
1163 	/* Allocate bigger log buffer */
1164 	setup_log_buf(1);
1165 
1166 	if (efi_enabled(EFI_BOOT)) {
1167 		switch (boot_params.secure_boot) {
1168 		case efi_secureboot_mode_disabled:
1169 			pr_info("Secure boot disabled\n");
1170 			break;
1171 		case efi_secureboot_mode_enabled:
1172 			pr_info("Secure boot enabled\n");
1173 			break;
1174 		default:
1175 			pr_info("Secure boot could not be determined\n");
1176 			break;
1177 		}
1178 	}
1179 
1180 	reserve_initrd();
1181 
1182 	acpi_table_upgrade();
1183 
1184 	vsmp_init();
1185 
1186 	io_delay_init();
1187 
1188 	early_platform_quirks();
1189 
1190 	/*
1191 	 * Parse the ACPI tables for possible boot-time SMP configuration.
1192 	 */
1193 	acpi_boot_table_init();
1194 
1195 	early_acpi_boot_init();
1196 
1197 	initmem_init();
1198 	dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT);
1199 
1200 	/*
1201 	 * Reserve memory for crash kernel after SRAT is parsed so that it
1202 	 * won't consume hotpluggable memory.
1203 	 */
1204 	reserve_crashkernel();
1205 
1206 	memblock_find_dma_reserve();
1207 
1208 	if (!early_xdbc_setup_hardware())
1209 		early_xdbc_register_console();
1210 
1211 	x86_init.paging.pagetable_init();
1212 
1213 	kasan_init();
1214 
1215 	/*
1216 	 * Sync back kernel address range.
1217 	 *
1218 	 * FIXME: Can the later sync in setup_cpu_entry_areas() replace
1219 	 * this call?
1220 	 */
1221 	sync_initial_page_table();
1222 
1223 	tboot_probe();
1224 
1225 	map_vsyscall();
1226 
1227 	generic_apic_probe();
1228 
1229 	early_quirks();
1230 
1231 	/*
1232 	 * Read APIC and some other early information from ACPI tables.
1233 	 */
1234 	acpi_boot_init();
1235 	sfi_init();
1236 	x86_dtb_init();
1237 
1238 	/*
1239 	 * get boot-time SMP configuration:
1240 	 */
1241 	get_smp_config();
1242 
1243 	/*
1244 	 * Systems w/o ACPI and mptables might not have it mapped the local
1245 	 * APIC yet, but prefill_possible_map() might need to access it.
1246 	 */
1247 	init_apic_mappings();
1248 
1249 	prefill_possible_map();
1250 
1251 	init_cpu_to_node();
1252 
1253 	io_apic_init_mappings();
1254 
1255 	x86_init.hyper.guest_late_init();
1256 
1257 	e820__reserve_resources();
1258 	e820__register_nosave_regions(max_pfn);
1259 
1260 	x86_init.resources.reserve_resources();
1261 
1262 	e820__setup_pci_gap();
1263 
1264 #ifdef CONFIG_VT
1265 #if defined(CONFIG_VGA_CONSOLE)
1266 	if (!efi_enabled(EFI_BOOT) || (efi_mem_type(0xa0000) != EFI_CONVENTIONAL_MEMORY))
1267 		conswitchp = &vga_con;
1268 #elif defined(CONFIG_DUMMY_CONSOLE)
1269 	conswitchp = &dummy_con;
1270 #endif
1271 #endif
1272 	x86_init.oem.banner();
1273 
1274 	x86_init.timers.wallclock_init();
1275 
1276 	mcheck_init();
1277 
1278 	register_refined_jiffies(CLOCK_TICK_RATE);
1279 
1280 #ifdef CONFIG_EFI
1281 	if (efi_enabled(EFI_BOOT))
1282 		efi_apply_memmap_quirks();
1283 #endif
1284 
1285 	unwind_init();
1286 }
1287 
1288 #ifdef CONFIG_X86_32
1289 
1290 static struct resource video_ram_resource = {
1291 	.name	= "Video RAM area",
1292 	.start	= 0xa0000,
1293 	.end	= 0xbffff,
1294 	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM
1295 };
1296 
1297 void __init i386_reserve_resources(void)
1298 {
1299 	request_resource(&iomem_resource, &video_ram_resource);
1300 	reserve_standard_io_resources();
1301 }
1302 
1303 #endif /* CONFIG_X86_32 */
1304 
1305 static struct notifier_block kernel_offset_notifier = {
1306 	.notifier_call = dump_kernel_offset
1307 };
1308 
1309 static int __init register_kernel_offset_dumper(void)
1310 {
1311 	atomic_notifier_chain_register(&panic_notifier_list,
1312 					&kernel_offset_notifier);
1313 	return 0;
1314 }
1315 __initcall(register_kernel_offset_dumper);
1316