xref: /openbmc/linux/arch/x86/kernel/setup.c (revision 941e1d36)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  Copyright (C) 1995  Linus Torvalds
4  *
5  *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
6  *
7  *  Memory region support
8  *	David Parsons <orc@pell.chi.il.us>, July-August 1999
9  *
10  *  Added E820 sanitization routine (removes overlapping memory regions);
11  *  Brian Moyle <bmoyle@mvista.com>, February 2001
12  *
13  * Moved CPU detection code to cpu/${cpu}.c
14  *    Patrick Mochel <mochel@osdl.org>, March 2002
15  *
16  *  Provisions for empty E820 memory regions (reported by certain BIOSes).
17  *  Alex Achenbach <xela@slit.de>, December 2002.
18  *
19  */
20 
21 /*
22  * This file handles the architecture-dependent parts of initialization
23  */
24 
25 #include <linux/sched.h>
26 #include <linux/mm.h>
27 #include <linux/mmzone.h>
28 #include <linux/screen_info.h>
29 #include <linux/ioport.h>
30 #include <linux/acpi.h>
31 #include <linux/sfi.h>
32 #include <linux/apm_bios.h>
33 #include <linux/initrd.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/export.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 #include <xen/xen.h>
54 #include <uapi/linux/mount.h>
55 
56 #include <linux/errno.h>
57 #include <linux/kernel.h>
58 #include <linux/stddef.h>
59 #include <linux/unistd.h>
60 #include <linux/ptrace.h>
61 #include <linux/user.h>
62 #include <linux/delay.h>
63 
64 #include <linux/kallsyms.h>
65 #include <linux/cpufreq.h>
66 #include <linux/dma-mapping.h>
67 #include <linux/ctype.h>
68 #include <linux/uaccess.h>
69 
70 #include <linux/percpu.h>
71 #include <linux/crash_dump.h>
72 #include <linux/tboot.h>
73 #include <linux/jiffies.h>
74 #include <linux/mem_encrypt.h>
75 #include <linux/sizes.h>
76 
77 #include <linux/usb/xhci-dbgp.h>
78 #include <video/edid.h>
79 
80 #include <asm/mtrr.h>
81 #include <asm/apic.h>
82 #include <asm/realmode.h>
83 #include <asm/e820/api.h>
84 #include <asm/mpspec.h>
85 #include <asm/setup.h>
86 #include <asm/efi.h>
87 #include <asm/timer.h>
88 #include <asm/i8259.h>
89 #include <asm/sections.h>
90 #include <asm/io_apic.h>
91 #include <asm/ist.h>
92 #include <asm/setup_arch.h>
93 #include <asm/bios_ebda.h>
94 #include <asm/cacheflush.h>
95 #include <asm/processor.h>
96 #include <asm/bugs.h>
97 #include <asm/kasan.h>
98 
99 #include <asm/vsyscall.h>
100 #include <asm/cpu.h>
101 #include <asm/desc.h>
102 #include <asm/dma.h>
103 #include <asm/iommu.h>
104 #include <asm/gart.h>
105 #include <asm/mmu_context.h>
106 #include <asm/proto.h>
107 
108 #include <asm/paravirt.h>
109 #include <asm/hypervisor.h>
110 #include <asm/olpc_ofw.h>
111 
112 #include <asm/percpu.h>
113 #include <asm/topology.h>
114 #include <asm/apicdef.h>
115 #include <asm/amd_nb.h>
116 #include <asm/mce.h>
117 #include <asm/alternative.h>
118 #include <asm/prom.h>
119 #include <asm/microcode.h>
120 #include <asm/kaslr.h>
121 #include <asm/unwind.h>
122 
123 /*
124  * max_low_pfn_mapped: highest direct mapped pfn under 4GB
125  * max_pfn_mapped:     highest direct mapped pfn over 4GB
126  *
127  * The direct mapping only covers E820_TYPE_RAM regions, so the ranges and gaps are
128  * represented by pfn_mapped
129  */
130 unsigned long max_low_pfn_mapped;
131 unsigned long max_pfn_mapped;
132 
133 #ifdef CONFIG_DMI
134 RESERVE_BRK(dmi_alloc, 65536);
135 #endif
136 
137 
138 static __initdata unsigned long _brk_start = (unsigned long)__brk_base;
139 unsigned long _brk_end = (unsigned long)__brk_base;
140 
141 struct boot_params boot_params;
142 
143 /*
144  * Machine setup..
145  */
146 static struct resource data_resource = {
147 	.name	= "Kernel data",
148 	.start	= 0,
149 	.end	= 0,
150 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
151 };
152 
153 static struct resource code_resource = {
154 	.name	= "Kernel code",
155 	.start	= 0,
156 	.end	= 0,
157 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
158 };
159 
160 static struct resource bss_resource = {
161 	.name	= "Kernel bss",
162 	.start	= 0,
163 	.end	= 0,
164 	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
165 };
166 
167 
168 #ifdef CONFIG_X86_32
169 /* cpu data as detected by the assembly code in head_32.S */
170 struct cpuinfo_x86 new_cpu_data;
171 
172 /* common cpu data for all cpus */
173 struct cpuinfo_x86 boot_cpu_data __read_mostly;
174 EXPORT_SYMBOL(boot_cpu_data);
175 
176 unsigned int def_to_bigsmp;
177 
178 /* for MCA, but anyone else can use it if they want */
179 unsigned int machine_id;
180 unsigned int machine_submodel_id;
181 unsigned int BIOS_revision;
182 
183 struct apm_info apm_info;
184 EXPORT_SYMBOL(apm_info);
185 
186 #if defined(CONFIG_X86_SPEEDSTEP_SMI) || \
187 	defined(CONFIG_X86_SPEEDSTEP_SMI_MODULE)
188 struct ist_info ist_info;
189 EXPORT_SYMBOL(ist_info);
190 #else
191 struct ist_info ist_info;
192 #endif
193 
194 #else
195 struct cpuinfo_x86 boot_cpu_data __read_mostly;
196 EXPORT_SYMBOL(boot_cpu_data);
197 #endif
198 
199 
200 #if !defined(CONFIG_X86_PAE) || defined(CONFIG_X86_64)
201 __visible unsigned long mmu_cr4_features __ro_after_init;
202 #else
203 __visible unsigned long mmu_cr4_features __ro_after_init = X86_CR4_PAE;
204 #endif
205 
206 /* Boot loader ID and version as integers, for the benefit of proc_dointvec */
207 int bootloader_type, bootloader_version;
208 
209 /*
210  * Setup options
211  */
212 struct screen_info screen_info;
213 EXPORT_SYMBOL(screen_info);
214 struct edid_info edid_info;
215 EXPORT_SYMBOL_GPL(edid_info);
216 
217 extern int root_mountflags;
218 
219 unsigned long saved_video_mode;
220 
221 #define RAMDISK_IMAGE_START_MASK	0x07FF
222 #define RAMDISK_PROMPT_FLAG		0x8000
223 #define RAMDISK_LOAD_FLAG		0x4000
224 
225 static char __initdata command_line[COMMAND_LINE_SIZE];
226 #ifdef CONFIG_CMDLINE_BOOL
227 static char __initdata builtin_cmdline[COMMAND_LINE_SIZE] = CONFIG_CMDLINE;
228 #endif
229 
230 #if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
231 struct edd edd;
232 #ifdef CONFIG_EDD_MODULE
233 EXPORT_SYMBOL(edd);
234 #endif
235 /**
236  * copy_edd() - Copy the BIOS EDD information
237  *              from boot_params into a safe place.
238  *
239  */
240 static inline void __init copy_edd(void)
241 {
242      memcpy(edd.mbr_signature, boot_params.edd_mbr_sig_buffer,
243 	    sizeof(edd.mbr_signature));
244      memcpy(edd.edd_info, boot_params.eddbuf, sizeof(edd.edd_info));
245      edd.mbr_signature_nr = boot_params.edd_mbr_sig_buf_entries;
246      edd.edd_info_nr = boot_params.eddbuf_entries;
247 }
248 #else
249 static inline void __init copy_edd(void)
250 {
251 }
252 #endif
253 
254 void * __init extend_brk(size_t size, size_t align)
255 {
256 	size_t mask = align - 1;
257 	void *ret;
258 
259 	BUG_ON(_brk_start == 0);
260 	BUG_ON(align & mask);
261 
262 	_brk_end = (_brk_end + mask) & ~mask;
263 	BUG_ON((char *)(_brk_end + size) > __brk_limit);
264 
265 	ret = (void *)_brk_end;
266 	_brk_end += size;
267 
268 	memset(ret, 0, size);
269 
270 	return ret;
271 }
272 
273 #ifdef CONFIG_X86_32
274 static void __init cleanup_highmap(void)
275 {
276 }
277 #endif
278 
279 static void __init reserve_brk(void)
280 {
281 	if (_brk_end > _brk_start)
282 		memblock_reserve(__pa_symbol(_brk_start),
283 				 _brk_end - _brk_start);
284 
285 	/* Mark brk area as locked down and no longer taking any
286 	   new allocations */
287 	_brk_start = 0;
288 }
289 
290 u64 relocated_ramdisk;
291 
292 #ifdef CONFIG_BLK_DEV_INITRD
293 
294 static u64 __init get_ramdisk_image(void)
295 {
296 	u64 ramdisk_image = boot_params.hdr.ramdisk_image;
297 
298 	ramdisk_image |= (u64)boot_params.ext_ramdisk_image << 32;
299 
300 	return ramdisk_image;
301 }
302 static u64 __init get_ramdisk_size(void)
303 {
304 	u64 ramdisk_size = boot_params.hdr.ramdisk_size;
305 
306 	ramdisk_size |= (u64)boot_params.ext_ramdisk_size << 32;
307 
308 	return ramdisk_size;
309 }
310 
311 static void __init relocate_initrd(void)
312 {
313 	/* Assume only end is not page aligned */
314 	u64 ramdisk_image = get_ramdisk_image();
315 	u64 ramdisk_size  = get_ramdisk_size();
316 	u64 area_size     = PAGE_ALIGN(ramdisk_size);
317 
318 	/* We need to move the initrd down into directly mapped mem */
319 	relocated_ramdisk = memblock_find_in_range(0, PFN_PHYS(max_pfn_mapped),
320 						   area_size, PAGE_SIZE);
321 
322 	if (!relocated_ramdisk)
323 		panic("Cannot find place for new RAMDISK of size %lld\n",
324 		      ramdisk_size);
325 
326 	/* Note: this includes all the mem currently occupied by
327 	   the initrd, we rely on that fact to keep the data intact. */
328 	memblock_reserve(relocated_ramdisk, area_size);
329 	initrd_start = relocated_ramdisk + PAGE_OFFSET;
330 	initrd_end   = initrd_start + ramdisk_size;
331 	printk(KERN_INFO "Allocated new RAMDISK: [mem %#010llx-%#010llx]\n",
332 	       relocated_ramdisk, relocated_ramdisk + ramdisk_size - 1);
333 
334 	copy_from_early_mem((void *)initrd_start, ramdisk_image, ramdisk_size);
335 
336 	printk(KERN_INFO "Move RAMDISK from [mem %#010llx-%#010llx] to"
337 		" [mem %#010llx-%#010llx]\n",
338 		ramdisk_image, ramdisk_image + ramdisk_size - 1,
339 		relocated_ramdisk, relocated_ramdisk + ramdisk_size - 1);
340 }
341 
342 static void __init early_reserve_initrd(void)
343 {
344 	/* Assume only end is not page aligned */
345 	u64 ramdisk_image = get_ramdisk_image();
346 	u64 ramdisk_size  = get_ramdisk_size();
347 	u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
348 
349 	if (!boot_params.hdr.type_of_loader ||
350 	    !ramdisk_image || !ramdisk_size)
351 		return;		/* No initrd provided by bootloader */
352 
353 	memblock_reserve(ramdisk_image, ramdisk_end - ramdisk_image);
354 }
355 static void __init reserve_initrd(void)
356 {
357 	/* Assume only end is not page aligned */
358 	u64 ramdisk_image = get_ramdisk_image();
359 	u64 ramdisk_size  = get_ramdisk_size();
360 	u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
361 	u64 mapped_size;
362 
363 	if (!boot_params.hdr.type_of_loader ||
364 	    !ramdisk_image || !ramdisk_size)
365 		return;		/* No initrd provided by bootloader */
366 
367 	initrd_start = 0;
368 
369 	mapped_size = memblock_mem_size(max_pfn_mapped);
370 	if (ramdisk_size >= (mapped_size>>1))
371 		panic("initrd too large to handle, "
372 		       "disabling initrd (%lld needed, %lld available)\n",
373 		       ramdisk_size, mapped_size>>1);
374 
375 	printk(KERN_INFO "RAMDISK: [mem %#010llx-%#010llx]\n", ramdisk_image,
376 			ramdisk_end - 1);
377 
378 	if (pfn_range_is_mapped(PFN_DOWN(ramdisk_image),
379 				PFN_DOWN(ramdisk_end))) {
380 		/* All are mapped, easy case */
381 		initrd_start = ramdisk_image + PAGE_OFFSET;
382 		initrd_end = initrd_start + ramdisk_size;
383 		return;
384 	}
385 
386 	relocate_initrd();
387 
388 	memblock_free(ramdisk_image, ramdisk_end - ramdisk_image);
389 }
390 
391 #else
392 static void __init early_reserve_initrd(void)
393 {
394 }
395 static void __init reserve_initrd(void)
396 {
397 }
398 #endif /* CONFIG_BLK_DEV_INITRD */
399 
400 static void __init parse_setup_data(void)
401 {
402 	struct setup_data *data;
403 	u64 pa_data, pa_next;
404 
405 	pa_data = boot_params.hdr.setup_data;
406 	while (pa_data) {
407 		u32 data_len, data_type;
408 
409 		data = early_memremap(pa_data, sizeof(*data));
410 		data_len = data->len + sizeof(struct setup_data);
411 		data_type = data->type;
412 		pa_next = data->next;
413 		early_memunmap(data, sizeof(*data));
414 
415 		switch (data_type) {
416 		case SETUP_E820_EXT:
417 			e820__memory_setup_extended(pa_data, data_len);
418 			break;
419 		case SETUP_DTB:
420 			add_dtb(pa_data);
421 			break;
422 		case SETUP_EFI:
423 			parse_efi_setup(pa_data, data_len);
424 			break;
425 		default:
426 			break;
427 		}
428 		pa_data = pa_next;
429 	}
430 }
431 
432 static void __init memblock_x86_reserve_range_setup_data(void)
433 {
434 	struct setup_data *data;
435 	u64 pa_data;
436 
437 	pa_data = boot_params.hdr.setup_data;
438 	while (pa_data) {
439 		data = early_memremap(pa_data, sizeof(*data));
440 		memblock_reserve(pa_data, sizeof(*data) + data->len);
441 		pa_data = data->next;
442 		early_memunmap(data, sizeof(*data));
443 	}
444 }
445 
446 /*
447  * --------- Crashkernel reservation ------------------------------
448  */
449 
450 #ifdef CONFIG_KEXEC_CORE
451 
452 /* 16M alignment for crash kernel regions */
453 #define CRASH_ALIGN		SZ_16M
454 
455 /*
456  * Keep the crash kernel below this limit.
457  *
458  * On 32 bits earlier kernels would limit the kernel to the low 512 MiB
459  * due to mapping restrictions.
460  *
461  * On 64bit, kdump kernel need be restricted to be under 64TB, which is
462  * the upper limit of system RAM in 4-level paing mode. Since the kdump
463  * jumping could be from 5-level to 4-level, the jumping will fail if
464  * kernel is put above 64TB, and there's no way to detect the paging mode
465  * of the kernel which will be loaded for dumping during the 1st kernel
466  * bootup.
467  */
468 #ifdef CONFIG_X86_32
469 # define CRASH_ADDR_LOW_MAX	SZ_512M
470 # define CRASH_ADDR_HIGH_MAX	SZ_512M
471 #else
472 # define CRASH_ADDR_LOW_MAX	SZ_4G
473 # define CRASH_ADDR_HIGH_MAX	SZ_64T
474 #endif
475 
476 static int __init reserve_crashkernel_low(void)
477 {
478 #ifdef CONFIG_X86_64
479 	unsigned long long base, low_base = 0, low_size = 0;
480 	unsigned long total_low_mem;
481 	int ret;
482 
483 	total_low_mem = memblock_mem_size(1UL << (32 - PAGE_SHIFT));
484 
485 	/* crashkernel=Y,low */
486 	ret = parse_crashkernel_low(boot_command_line, total_low_mem, &low_size, &base);
487 	if (ret) {
488 		/*
489 		 * two parts from kernel/dma/swiotlb.c:
490 		 * -swiotlb size: user-specified with swiotlb= or default.
491 		 *
492 		 * -swiotlb overflow buffer: now hardcoded to 32k. We round it
493 		 * to 8M for other buffers that may need to stay low too. Also
494 		 * make sure we allocate enough extra low memory so that we
495 		 * don't run out of DMA buffers for 32-bit devices.
496 		 */
497 		low_size = max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20);
498 	} else {
499 		/* passed with crashkernel=0,low ? */
500 		if (!low_size)
501 			return 0;
502 	}
503 
504 	low_base = memblock_find_in_range(0, 1ULL << 32, low_size, CRASH_ALIGN);
505 	if (!low_base) {
506 		pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n",
507 		       (unsigned long)(low_size >> 20));
508 		return -ENOMEM;
509 	}
510 
511 	ret = memblock_reserve(low_base, low_size);
512 	if (ret) {
513 		pr_err("%s: Error reserving crashkernel low memblock.\n", __func__);
514 		return ret;
515 	}
516 
517 	pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (System low RAM: %ldMB)\n",
518 		(unsigned long)(low_size >> 20),
519 		(unsigned long)(low_base >> 20),
520 		(unsigned long)(total_low_mem >> 20));
521 
522 	crashk_low_res.start = low_base;
523 	crashk_low_res.end   = low_base + low_size - 1;
524 	insert_resource(&iomem_resource, &crashk_low_res);
525 #endif
526 	return 0;
527 }
528 
529 static void __init reserve_crashkernel(void)
530 {
531 	unsigned long long crash_size, crash_base, total_mem;
532 	bool high = false;
533 	int ret;
534 
535 	total_mem = memblock_phys_mem_size();
536 
537 	/* crashkernel=XM */
538 	ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base);
539 	if (ret != 0 || crash_size <= 0) {
540 		/* crashkernel=X,high */
541 		ret = parse_crashkernel_high(boot_command_line, total_mem,
542 					     &crash_size, &crash_base);
543 		if (ret != 0 || crash_size <= 0)
544 			return;
545 		high = true;
546 	}
547 
548 	if (xen_pv_domain()) {
549 		pr_info("Ignoring crashkernel for a Xen PV domain\n");
550 		return;
551 	}
552 
553 	/* 0 means: find the address automatically */
554 	if (!crash_base) {
555 		/*
556 		 * Set CRASH_ADDR_LOW_MAX upper bound for crash memory,
557 		 * crashkernel=x,high reserves memory over 4G, also allocates
558 		 * 256M extra low memory for DMA buffers and swiotlb.
559 		 * But the extra memory is not required for all machines.
560 		 * So try low memory first and fall back to high memory
561 		 * unless "crashkernel=size[KMG],high" is specified.
562 		 */
563 		if (!high)
564 			crash_base = memblock_find_in_range(CRASH_ALIGN,
565 						CRASH_ADDR_LOW_MAX,
566 						crash_size, CRASH_ALIGN);
567 		if (!crash_base)
568 			crash_base = memblock_find_in_range(CRASH_ALIGN,
569 						CRASH_ADDR_HIGH_MAX,
570 						crash_size, CRASH_ALIGN);
571 		if (!crash_base) {
572 			pr_info("crashkernel reservation failed - No suitable area found.\n");
573 			return;
574 		}
575 	} else {
576 		unsigned long long start;
577 
578 		start = memblock_find_in_range(crash_base,
579 					       crash_base + crash_size,
580 					       crash_size, 1 << 20);
581 		if (start != crash_base) {
582 			pr_info("crashkernel reservation failed - memory is in use.\n");
583 			return;
584 		}
585 	}
586 	ret = memblock_reserve(crash_base, crash_size);
587 	if (ret) {
588 		pr_err("%s: Error reserving crashkernel memblock.\n", __func__);
589 		return;
590 	}
591 
592 	if (crash_base >= (1ULL << 32) && reserve_crashkernel_low()) {
593 		memblock_free(crash_base, crash_size);
594 		return;
595 	}
596 
597 	pr_info("Reserving %ldMB of memory at %ldMB for crashkernel (System RAM: %ldMB)\n",
598 		(unsigned long)(crash_size >> 20),
599 		(unsigned long)(crash_base >> 20),
600 		(unsigned long)(total_mem >> 20));
601 
602 	crashk_res.start = crash_base;
603 	crashk_res.end   = crash_base + crash_size - 1;
604 	insert_resource(&iomem_resource, &crashk_res);
605 }
606 #else
607 static void __init reserve_crashkernel(void)
608 {
609 }
610 #endif
611 
612 static struct resource standard_io_resources[] = {
613 	{ .name = "dma1", .start = 0x00, .end = 0x1f,
614 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
615 	{ .name = "pic1", .start = 0x20, .end = 0x21,
616 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
617 	{ .name = "timer0", .start = 0x40, .end = 0x43,
618 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
619 	{ .name = "timer1", .start = 0x50, .end = 0x53,
620 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
621 	{ .name = "keyboard", .start = 0x60, .end = 0x60,
622 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
623 	{ .name = "keyboard", .start = 0x64, .end = 0x64,
624 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
625 	{ .name = "dma page reg", .start = 0x80, .end = 0x8f,
626 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
627 	{ .name = "pic2", .start = 0xa0, .end = 0xa1,
628 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
629 	{ .name = "dma2", .start = 0xc0, .end = 0xdf,
630 		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
631 	{ .name = "fpu", .start = 0xf0, .end = 0xff,
632 		.flags = IORESOURCE_BUSY | IORESOURCE_IO }
633 };
634 
635 void __init reserve_standard_io_resources(void)
636 {
637 	int i;
638 
639 	/* request I/O space for devices used on all i[345]86 PCs */
640 	for (i = 0; i < ARRAY_SIZE(standard_io_resources); i++)
641 		request_resource(&ioport_resource, &standard_io_resources[i]);
642 
643 }
644 
645 static __init void reserve_ibft_region(void)
646 {
647 	unsigned long addr, size = 0;
648 
649 	addr = find_ibft_region(&size);
650 
651 	if (size)
652 		memblock_reserve(addr, size);
653 }
654 
655 static bool __init snb_gfx_workaround_needed(void)
656 {
657 #ifdef CONFIG_PCI
658 	int i;
659 	u16 vendor, devid;
660 	static const __initconst u16 snb_ids[] = {
661 		0x0102,
662 		0x0112,
663 		0x0122,
664 		0x0106,
665 		0x0116,
666 		0x0126,
667 		0x010a,
668 	};
669 
670 	/* Assume no if something weird is going on with PCI */
671 	if (!early_pci_allowed())
672 		return false;
673 
674 	vendor = read_pci_config_16(0, 2, 0, PCI_VENDOR_ID);
675 	if (vendor != 0x8086)
676 		return false;
677 
678 	devid = read_pci_config_16(0, 2, 0, PCI_DEVICE_ID);
679 	for (i = 0; i < ARRAY_SIZE(snb_ids); i++)
680 		if (devid == snb_ids[i])
681 			return true;
682 #endif
683 
684 	return false;
685 }
686 
687 /*
688  * Sandy Bridge graphics has trouble with certain ranges, exclude
689  * them from allocation.
690  */
691 static void __init trim_snb_memory(void)
692 {
693 	static const __initconst unsigned long bad_pages[] = {
694 		0x20050000,
695 		0x20110000,
696 		0x20130000,
697 		0x20138000,
698 		0x40004000,
699 	};
700 	int i;
701 
702 	if (!snb_gfx_workaround_needed())
703 		return;
704 
705 	printk(KERN_DEBUG "reserving inaccessible SNB gfx pages\n");
706 
707 	/*
708 	 * Reserve all memory below the 1 MB mark that has not
709 	 * already been reserved.
710 	 */
711 	memblock_reserve(0, 1<<20);
712 
713 	for (i = 0; i < ARRAY_SIZE(bad_pages); i++) {
714 		if (memblock_reserve(bad_pages[i], PAGE_SIZE))
715 			printk(KERN_WARNING "failed to reserve 0x%08lx\n",
716 			       bad_pages[i]);
717 	}
718 }
719 
720 /*
721  * Here we put platform-specific memory range workarounds, i.e.
722  * memory known to be corrupt or otherwise in need to be reserved on
723  * specific platforms.
724  *
725  * If this gets used more widely it could use a real dispatch mechanism.
726  */
727 static void __init trim_platform_memory_ranges(void)
728 {
729 	trim_snb_memory();
730 }
731 
732 static void __init trim_bios_range(void)
733 {
734 	/*
735 	 * A special case is the first 4Kb of memory;
736 	 * This is a BIOS owned area, not kernel ram, but generally
737 	 * not listed as such in the E820 table.
738 	 *
739 	 * This typically reserves additional memory (64KiB by default)
740 	 * since some BIOSes are known to corrupt low memory.  See the
741 	 * Kconfig help text for X86_RESERVE_LOW.
742 	 */
743 	e820__range_update(0, PAGE_SIZE, E820_TYPE_RAM, E820_TYPE_RESERVED);
744 
745 	/*
746 	 * special case: Some BIOSen report the PC BIOS
747 	 * area (640->1Mb) as ram even though it is not.
748 	 * take them out.
749 	 */
750 	e820__range_remove(BIOS_BEGIN, BIOS_END - BIOS_BEGIN, E820_TYPE_RAM, 1);
751 
752 	e820__update_table(e820_table);
753 }
754 
755 /* called before trim_bios_range() to spare extra sanitize */
756 static void __init e820_add_kernel_range(void)
757 {
758 	u64 start = __pa_symbol(_text);
759 	u64 size = __pa_symbol(_end) - start;
760 
761 	/*
762 	 * Complain if .text .data and .bss are not marked as E820_TYPE_RAM and
763 	 * attempt to fix it by adding the range. We may have a confused BIOS,
764 	 * or the user may have used memmap=exactmap or memmap=xxM$yyM to
765 	 * exclude kernel range. If we really are running on top non-RAM,
766 	 * we will crash later anyways.
767 	 */
768 	if (e820__mapped_all(start, start + size, E820_TYPE_RAM))
769 		return;
770 
771 	pr_warn(".text .data .bss are not marked as E820_TYPE_RAM!\n");
772 	e820__range_remove(start, size, E820_TYPE_RAM, 0);
773 	e820__range_add(start, size, E820_TYPE_RAM);
774 }
775 
776 static unsigned reserve_low = CONFIG_X86_RESERVE_LOW << 10;
777 
778 static int __init parse_reservelow(char *p)
779 {
780 	unsigned long long size;
781 
782 	if (!p)
783 		return -EINVAL;
784 
785 	size = memparse(p, &p);
786 
787 	if (size < 4096)
788 		size = 4096;
789 
790 	if (size > 640*1024)
791 		size = 640*1024;
792 
793 	reserve_low = size;
794 
795 	return 0;
796 }
797 
798 early_param("reservelow", parse_reservelow);
799 
800 static void __init trim_low_memory_range(void)
801 {
802 	memblock_reserve(0, ALIGN(reserve_low, PAGE_SIZE));
803 }
804 
805 /*
806  * Dump out kernel offset information on panic.
807  */
808 static int
809 dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
810 {
811 	if (kaslr_enabled()) {
812 		pr_emerg("Kernel Offset: 0x%lx from 0x%lx (relocation range: 0x%lx-0x%lx)\n",
813 			 kaslr_offset(),
814 			 __START_KERNEL,
815 			 __START_KERNEL_map,
816 			 MODULES_VADDR-1);
817 	} else {
818 		pr_emerg("Kernel Offset: disabled\n");
819 	}
820 
821 	return 0;
822 }
823 
824 /*
825  * Determine if we were loaded by an EFI loader.  If so, then we have also been
826  * passed the efi memmap, systab, etc., so we should use these data structures
827  * for initialization.  Note, the efi init code path is determined by the
828  * global efi_enabled. This allows the same kernel image to be used on existing
829  * systems (with a traditional BIOS) as well as on EFI systems.
830  */
831 /*
832  * setup_arch - architecture-specific boot-time initializations
833  *
834  * Note: On x86_64, fixmaps are ready for use even before this is called.
835  */
836 
837 void __init setup_arch(char **cmdline_p)
838 {
839 	/*
840 	 * Reserve the memory occupied by the kernel between _text and
841 	 * __end_of_kernel_reserve symbols. Any kernel sections after the
842 	 * __end_of_kernel_reserve symbol must be explicitly reserved with a
843 	 * separate memblock_reserve() or they will be discarded.
844 	 */
845 	memblock_reserve(__pa_symbol(_text),
846 			 (unsigned long)__end_of_kernel_reserve - (unsigned long)_text);
847 
848 	/*
849 	 * Make sure page 0 is always reserved because on systems with
850 	 * L1TF its contents can be leaked to user processes.
851 	 */
852 	memblock_reserve(0, PAGE_SIZE);
853 
854 	early_reserve_initrd();
855 
856 	/*
857 	 * At this point everything still needed from the boot loader
858 	 * or BIOS or kernel text should be early reserved or marked not
859 	 * RAM in e820. All other memory is free game.
860 	 */
861 
862 #ifdef CONFIG_X86_32
863 	memcpy(&boot_cpu_data, &new_cpu_data, sizeof(new_cpu_data));
864 
865 	/*
866 	 * copy kernel address range established so far and switch
867 	 * to the proper swapper page table
868 	 */
869 	clone_pgd_range(swapper_pg_dir     + KERNEL_PGD_BOUNDARY,
870 			initial_page_table + KERNEL_PGD_BOUNDARY,
871 			KERNEL_PGD_PTRS);
872 
873 	load_cr3(swapper_pg_dir);
874 	/*
875 	 * Note: Quark X1000 CPUs advertise PGE incorrectly and require
876 	 * a cr3 based tlb flush, so the following __flush_tlb_all()
877 	 * will not flush anything because the cpu quirk which clears
878 	 * X86_FEATURE_PGE has not been invoked yet. Though due to the
879 	 * load_cr3() above the TLB has been flushed already. The
880 	 * quirk is invoked before subsequent calls to __flush_tlb_all()
881 	 * so proper operation is guaranteed.
882 	 */
883 	__flush_tlb_all();
884 #else
885 	printk(KERN_INFO "Command line: %s\n", boot_command_line);
886 	boot_cpu_data.x86_phys_bits = MAX_PHYSMEM_BITS;
887 #endif
888 
889 	/*
890 	 * If we have OLPC OFW, we might end up relocating the fixmap due to
891 	 * reserve_top(), so do this before touching the ioremap area.
892 	 */
893 	olpc_ofw_detect();
894 
895 	idt_setup_early_traps();
896 	early_cpu_init();
897 	arch_init_ideal_nops();
898 	jump_label_init();
899 	early_ioremap_init();
900 
901 	setup_olpc_ofw_pgd();
902 
903 	ROOT_DEV = old_decode_dev(boot_params.hdr.root_dev);
904 	screen_info = boot_params.screen_info;
905 	edid_info = boot_params.edid_info;
906 #ifdef CONFIG_X86_32
907 	apm_info.bios = boot_params.apm_bios_info;
908 	ist_info = boot_params.ist_info;
909 #endif
910 	saved_video_mode = boot_params.hdr.vid_mode;
911 	bootloader_type = boot_params.hdr.type_of_loader;
912 	if ((bootloader_type >> 4) == 0xe) {
913 		bootloader_type &= 0xf;
914 		bootloader_type |= (boot_params.hdr.ext_loader_type+0x10) << 4;
915 	}
916 	bootloader_version  = bootloader_type & 0xf;
917 	bootloader_version |= boot_params.hdr.ext_loader_ver << 4;
918 
919 #ifdef CONFIG_BLK_DEV_RAM
920 	rd_image_start = boot_params.hdr.ram_size & RAMDISK_IMAGE_START_MASK;
921 	rd_prompt = ((boot_params.hdr.ram_size & RAMDISK_PROMPT_FLAG) != 0);
922 	rd_doload = ((boot_params.hdr.ram_size & RAMDISK_LOAD_FLAG) != 0);
923 #endif
924 #ifdef CONFIG_EFI
925 	if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
926 		     EFI32_LOADER_SIGNATURE, 4)) {
927 		set_bit(EFI_BOOT, &efi.flags);
928 	} else if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
929 		     EFI64_LOADER_SIGNATURE, 4)) {
930 		set_bit(EFI_BOOT, &efi.flags);
931 		set_bit(EFI_64BIT, &efi.flags);
932 	}
933 #endif
934 
935 	x86_init.oem.arch_setup();
936 
937 	iomem_resource.end = (1ULL << boot_cpu_data.x86_phys_bits) - 1;
938 	e820__memory_setup();
939 	parse_setup_data();
940 
941 	copy_edd();
942 
943 	if (!boot_params.hdr.root_flags)
944 		root_mountflags &= ~MS_RDONLY;
945 	init_mm.start_code = (unsigned long) _text;
946 	init_mm.end_code = (unsigned long) _etext;
947 	init_mm.end_data = (unsigned long) _edata;
948 	init_mm.brk = _brk_end;
949 
950 	mpx_mm_init(&init_mm);
951 
952 	code_resource.start = __pa_symbol(_text);
953 	code_resource.end = __pa_symbol(_etext)-1;
954 	data_resource.start = __pa_symbol(_etext);
955 	data_resource.end = __pa_symbol(_edata)-1;
956 	bss_resource.start = __pa_symbol(__bss_start);
957 	bss_resource.end = __pa_symbol(__bss_stop)-1;
958 
959 #ifdef CONFIG_CMDLINE_BOOL
960 #ifdef CONFIG_CMDLINE_OVERRIDE
961 	strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
962 #else
963 	if (builtin_cmdline[0]) {
964 		/* append boot loader cmdline to builtin */
965 		strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);
966 		strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);
967 		strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
968 	}
969 #endif
970 #endif
971 
972 	strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
973 	*cmdline_p = command_line;
974 
975 	/*
976 	 * x86_configure_nx() is called before parse_early_param() to detect
977 	 * whether hardware doesn't support NX (so that the early EHCI debug
978 	 * console setup can safely call set_fixmap()). It may then be called
979 	 * again from within noexec_setup() during parsing early parameters
980 	 * to honor the respective command line option.
981 	 */
982 	x86_configure_nx();
983 
984 	parse_early_param();
985 
986 	if (efi_enabled(EFI_BOOT))
987 		efi_memblock_x86_reserve_range();
988 #ifdef CONFIG_MEMORY_HOTPLUG
989 	/*
990 	 * Memory used by the kernel cannot be hot-removed because Linux
991 	 * cannot migrate the kernel pages. When memory hotplug is
992 	 * enabled, we should prevent memblock from allocating memory
993 	 * for the kernel.
994 	 *
995 	 * ACPI SRAT records all hotpluggable memory ranges. But before
996 	 * SRAT is parsed, we don't know about it.
997 	 *
998 	 * The kernel image is loaded into memory at very early time. We
999 	 * cannot prevent this anyway. So on NUMA system, we set any
1000 	 * node the kernel resides in as un-hotpluggable.
1001 	 *
1002 	 * Since on modern servers, one node could have double-digit
1003 	 * gigabytes memory, we can assume the memory around the kernel
1004 	 * image is also un-hotpluggable. So before SRAT is parsed, just
1005 	 * allocate memory near the kernel image to try the best to keep
1006 	 * the kernel away from hotpluggable memory.
1007 	 */
1008 	if (movable_node_is_enabled())
1009 		memblock_set_bottom_up(true);
1010 #endif
1011 
1012 	x86_report_nx();
1013 
1014 	/* after early param, so could get panic from serial */
1015 	memblock_x86_reserve_range_setup_data();
1016 
1017 	if (acpi_mps_check()) {
1018 #ifdef CONFIG_X86_LOCAL_APIC
1019 		disable_apic = 1;
1020 #endif
1021 		setup_clear_cpu_cap(X86_FEATURE_APIC);
1022 	}
1023 
1024 	e820__reserve_setup_data();
1025 	e820__finish_early_params();
1026 
1027 	if (efi_enabled(EFI_BOOT))
1028 		efi_init();
1029 
1030 	dmi_setup();
1031 
1032 	/*
1033 	 * VMware detection requires dmi to be available, so this
1034 	 * needs to be done after dmi_setup(), for the boot CPU.
1035 	 */
1036 	init_hypervisor_platform();
1037 
1038 	tsc_early_init();
1039 	x86_init.resources.probe_roms();
1040 
1041 	/* after parse_early_param, so could debug it */
1042 	insert_resource(&iomem_resource, &code_resource);
1043 	insert_resource(&iomem_resource, &data_resource);
1044 	insert_resource(&iomem_resource, &bss_resource);
1045 
1046 	e820_add_kernel_range();
1047 	trim_bios_range();
1048 #ifdef CONFIG_X86_32
1049 	if (ppro_with_ram_bug()) {
1050 		e820__range_update(0x70000000ULL, 0x40000ULL, E820_TYPE_RAM,
1051 				  E820_TYPE_RESERVED);
1052 		e820__update_table(e820_table);
1053 		printk(KERN_INFO "fixed physical RAM map:\n");
1054 		e820__print_table("bad_ppro");
1055 	}
1056 #else
1057 	early_gart_iommu_check();
1058 #endif
1059 
1060 	/*
1061 	 * partially used pages are not usable - thus
1062 	 * we are rounding upwards:
1063 	 */
1064 	max_pfn = e820__end_of_ram_pfn();
1065 
1066 	/* update e820 for memory not covered by WB MTRRs */
1067 	mtrr_bp_init();
1068 	if (mtrr_trim_uncached_memory(max_pfn))
1069 		max_pfn = e820__end_of_ram_pfn();
1070 
1071 	max_possible_pfn = max_pfn;
1072 
1073 	/*
1074 	 * This call is required when the CPU does not support PAT. If
1075 	 * mtrr_bp_init() invoked it already via pat_init() the call has no
1076 	 * effect.
1077 	 */
1078 	init_cache_modes();
1079 
1080 	/*
1081 	 * Define random base addresses for memory sections after max_pfn is
1082 	 * defined and before each memory section base is used.
1083 	 */
1084 	kernel_randomize_memory();
1085 
1086 #ifdef CONFIG_X86_32
1087 	/* max_low_pfn get updated here */
1088 	find_low_pfn_range();
1089 #else
1090 	check_x2apic();
1091 
1092 	/* How many end-of-memory variables you have, grandma! */
1093 	/* need this before calling reserve_initrd */
1094 	if (max_pfn > (1UL<<(32 - PAGE_SHIFT)))
1095 		max_low_pfn = e820__end_of_low_ram_pfn();
1096 	else
1097 		max_low_pfn = max_pfn;
1098 
1099 	high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
1100 #endif
1101 
1102 	/*
1103 	 * Find and reserve possible boot-time SMP configuration:
1104 	 */
1105 	find_smp_config();
1106 
1107 	reserve_ibft_region();
1108 
1109 	early_alloc_pgt_buf();
1110 
1111 	/*
1112 	 * Need to conclude brk, before e820__memblock_setup()
1113 	 *  it could use memblock_find_in_range, could overlap with
1114 	 *  brk area.
1115 	 */
1116 	reserve_brk();
1117 
1118 	cleanup_highmap();
1119 
1120 	memblock_set_current_limit(ISA_END_ADDRESS);
1121 	e820__memblock_setup();
1122 
1123 	reserve_bios_regions();
1124 
1125 	if (efi_enabled(EFI_MEMMAP)) {
1126 		efi_fake_memmap();
1127 		efi_find_mirror();
1128 		efi_esrt_init();
1129 
1130 		/*
1131 		 * The EFI specification says that boot service code won't be
1132 		 * called after ExitBootServices(). This is, in fact, a lie.
1133 		 */
1134 		efi_reserve_boot_services();
1135 	}
1136 
1137 	/* preallocate 4k for mptable mpc */
1138 	e820__memblock_alloc_reserved_mpc_new();
1139 
1140 #ifdef CONFIG_X86_CHECK_BIOS_CORRUPTION
1141 	setup_bios_corruption_check();
1142 #endif
1143 
1144 #ifdef CONFIG_X86_32
1145 	printk(KERN_DEBUG "initial memory mapped: [mem 0x00000000-%#010lx]\n",
1146 			(max_pfn_mapped<<PAGE_SHIFT) - 1);
1147 #endif
1148 
1149 	reserve_real_mode();
1150 
1151 	trim_platform_memory_ranges();
1152 	trim_low_memory_range();
1153 
1154 	init_mem_mapping();
1155 
1156 	idt_setup_early_pf();
1157 
1158 	/*
1159 	 * Update mmu_cr4_features (and, indirectly, trampoline_cr4_features)
1160 	 * with the current CR4 value.  This may not be necessary, but
1161 	 * auditing all the early-boot CR4 manipulation would be needed to
1162 	 * rule it out.
1163 	 *
1164 	 * Mask off features that don't work outside long mode (just
1165 	 * PCIDE for now).
1166 	 */
1167 	mmu_cr4_features = __read_cr4() & ~X86_CR4_PCIDE;
1168 
1169 	memblock_set_current_limit(get_max_mapped());
1170 
1171 	/*
1172 	 * NOTE: On x86-32, only from this point on, fixmaps are ready for use.
1173 	 */
1174 
1175 #ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
1176 	if (init_ohci1394_dma_early)
1177 		init_ohci1394_dma_on_all_controllers();
1178 #endif
1179 	/* Allocate bigger log buffer */
1180 	setup_log_buf(1);
1181 
1182 	if (efi_enabled(EFI_BOOT)) {
1183 		switch (boot_params.secure_boot) {
1184 		case efi_secureboot_mode_disabled:
1185 			pr_info("Secure boot disabled\n");
1186 			break;
1187 		case efi_secureboot_mode_enabled:
1188 			pr_info("Secure boot enabled\n");
1189 			break;
1190 		default:
1191 			pr_info("Secure boot could not be determined\n");
1192 			break;
1193 		}
1194 	}
1195 
1196 	reserve_initrd();
1197 
1198 	acpi_table_upgrade();
1199 
1200 	vsmp_init();
1201 
1202 	io_delay_init();
1203 
1204 	early_platform_quirks();
1205 
1206 	/*
1207 	 * Parse the ACPI tables for possible boot-time SMP configuration.
1208 	 */
1209 	acpi_boot_table_init();
1210 
1211 	early_acpi_boot_init();
1212 
1213 	initmem_init();
1214 	dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT);
1215 
1216 	/*
1217 	 * Reserve memory for crash kernel after SRAT is parsed so that it
1218 	 * won't consume hotpluggable memory.
1219 	 */
1220 	reserve_crashkernel();
1221 
1222 	memblock_find_dma_reserve();
1223 
1224 	if (!early_xdbc_setup_hardware())
1225 		early_xdbc_register_console();
1226 
1227 	x86_init.paging.pagetable_init();
1228 
1229 	kasan_init();
1230 
1231 	/*
1232 	 * Sync back kernel address range.
1233 	 *
1234 	 * FIXME: Can the later sync in setup_cpu_entry_areas() replace
1235 	 * this call?
1236 	 */
1237 	sync_initial_page_table();
1238 
1239 	tboot_probe();
1240 
1241 	map_vsyscall();
1242 
1243 	generic_apic_probe();
1244 
1245 	early_quirks();
1246 
1247 	/*
1248 	 * Read APIC and some other early information from ACPI tables.
1249 	 */
1250 	acpi_boot_init();
1251 	sfi_init();
1252 	x86_dtb_init();
1253 
1254 	/*
1255 	 * get boot-time SMP configuration:
1256 	 */
1257 	get_smp_config();
1258 
1259 	/*
1260 	 * Systems w/o ACPI and mptables might not have it mapped the local
1261 	 * APIC yet, but prefill_possible_map() might need to access it.
1262 	 */
1263 	init_apic_mappings();
1264 
1265 	prefill_possible_map();
1266 
1267 	init_cpu_to_node();
1268 
1269 	io_apic_init_mappings();
1270 
1271 	x86_init.hyper.guest_late_init();
1272 
1273 	e820__reserve_resources();
1274 	e820__register_nosave_regions(max_pfn);
1275 
1276 	x86_init.resources.reserve_resources();
1277 
1278 	e820__setup_pci_gap();
1279 
1280 #ifdef CONFIG_VT
1281 #if defined(CONFIG_VGA_CONSOLE)
1282 	if (!efi_enabled(EFI_BOOT) || (efi_mem_type(0xa0000) != EFI_CONVENTIONAL_MEMORY))
1283 		conswitchp = &vga_con;
1284 #elif defined(CONFIG_DUMMY_CONSOLE)
1285 	conswitchp = &dummy_con;
1286 #endif
1287 #endif
1288 	x86_init.oem.banner();
1289 
1290 	x86_init.timers.wallclock_init();
1291 
1292 	mcheck_init();
1293 
1294 	register_refined_jiffies(CLOCK_TICK_RATE);
1295 
1296 #ifdef CONFIG_EFI
1297 	if (efi_enabled(EFI_BOOT))
1298 		efi_apply_memmap_quirks();
1299 #endif
1300 
1301 	unwind_init();
1302 }
1303 
1304 #ifdef CONFIG_X86_32
1305 
1306 static struct resource video_ram_resource = {
1307 	.name	= "Video RAM area",
1308 	.start	= 0xa0000,
1309 	.end	= 0xbffff,
1310 	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM
1311 };
1312 
1313 void __init i386_reserve_resources(void)
1314 {
1315 	request_resource(&iomem_resource, &video_ram_resource);
1316 	reserve_standard_io_resources();
1317 }
1318 
1319 #endif /* CONFIG_X86_32 */
1320 
1321 static struct notifier_block kernel_offset_notifier = {
1322 	.notifier_call = dump_kernel_offset
1323 };
1324 
1325 static int __init register_kernel_offset_dumper(void)
1326 {
1327 	atomic_notifier_chain_register(&panic_notifier_list,
1328 					&kernel_offset_notifier);
1329 	return 0;
1330 }
1331 __initcall(register_kernel_offset_dumper);
1332