v4.19.13 snapshot.
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
new file mode 100644
index 0000000..b4866ba
--- /dev/null
+++ b/arch/x86/kernel/setup.c
@@ -0,0 +1,1311 @@
+/*
+ *  Copyright (C) 1995  Linus Torvalds
+ *
+ *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
+ *
+ *  Memory region support
+ *	David Parsons <orc@pell.chi.il.us>, July-August 1999
+ *
+ *  Added E820 sanitization routine (removes overlapping memory regions);
+ *  Brian Moyle <bmoyle@mvista.com>, February 2001
+ *
+ * Moved CPU detection code to cpu/${cpu}.c
+ *    Patrick Mochel <mochel@osdl.org>, March 2002
+ *
+ *  Provisions for empty E820 memory regions (reported by certain BIOSes).
+ *  Alex Achenbach <xela@slit.de>, December 2002.
+ *
+ */
+
+/*
+ * This file handles the architecture-dependent parts of initialization
+ */
+
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/mmzone.h>
+#include <linux/screen_info.h>
+#include <linux/ioport.h>
+#include <linux/acpi.h>
+#include <linux/sfi.h>
+#include <linux/apm_bios.h>
+#include <linux/initrd.h>
+#include <linux/bootmem.h>
+#include <linux/memblock.h>
+#include <linux/seq_file.h>
+#include <linux/console.h>
+#include <linux/root_dev.h>
+#include <linux/highmem.h>
+#include <linux/export.h>
+#include <linux/efi.h>
+#include <linux/init.h>
+#include <linux/edd.h>
+#include <linux/iscsi_ibft.h>
+#include <linux/nodemask.h>
+#include <linux/kexec.h>
+#include <linux/dmi.h>
+#include <linux/pfn.h>
+#include <linux/pci.h>
+#include <asm/pci-direct.h>
+#include <linux/init_ohci1394_dma.h>
+#include <linux/kvm_para.h>
+#include <linux/dma-contiguous.h>
+#include <xen/xen.h>
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/stddef.h>
+#include <linux/unistd.h>
+#include <linux/ptrace.h>
+#include <linux/user.h>
+#include <linux/delay.h>
+
+#include <linux/kallsyms.h>
+#include <linux/cpufreq.h>
+#include <linux/dma-mapping.h>
+#include <linux/ctype.h>
+#include <linux/uaccess.h>
+
+#include <linux/percpu.h>
+#include <linux/crash_dump.h>
+#include <linux/tboot.h>
+#include <linux/jiffies.h>
+#include <linux/mem_encrypt.h>
+
+#include <linux/usb/xhci-dbgp.h>
+#include <video/edid.h>
+
+#include <asm/mtrr.h>
+#include <asm/apic.h>
+#include <asm/realmode.h>
+#include <asm/e820/api.h>
+#include <asm/mpspec.h>
+#include <asm/setup.h>
+#include <asm/efi.h>
+#include <asm/timer.h>
+#include <asm/i8259.h>
+#include <asm/sections.h>
+#include <asm/io_apic.h>
+#include <asm/ist.h>
+#include <asm/setup_arch.h>
+#include <asm/bios_ebda.h>
+#include <asm/cacheflush.h>
+#include <asm/processor.h>
+#include <asm/bugs.h>
+#include <asm/kasan.h>
+
+#include <asm/vsyscall.h>
+#include <asm/cpu.h>
+#include <asm/desc.h>
+#include <asm/dma.h>
+#include <asm/iommu.h>
+#include <asm/gart.h>
+#include <asm/mmu_context.h>
+#include <asm/proto.h>
+
+#include <asm/paravirt.h>
+#include <asm/hypervisor.h>
+#include <asm/olpc_ofw.h>
+
+#include <asm/percpu.h>
+#include <asm/topology.h>
+#include <asm/apicdef.h>
+#include <asm/amd_nb.h>
+#include <asm/mce.h>
+#include <asm/alternative.h>
+#include <asm/prom.h>
+#include <asm/microcode.h>
+#include <asm/kaslr.h>
+#include <asm/unwind.h>
+
+/*
+ * max_low_pfn_mapped: highest direct mapped pfn under 4GB
+ * max_pfn_mapped:     highest direct mapped pfn over 4GB
+ *
+ * The direct mapping only covers E820_TYPE_RAM regions, so the ranges and gaps are
+ * represented by pfn_mapped
+ */
+unsigned long max_low_pfn_mapped;
+unsigned long max_pfn_mapped;
+
+#ifdef CONFIG_DMI
+RESERVE_BRK(dmi_alloc, 65536);
+#endif
+
+
+static __initdata unsigned long _brk_start = (unsigned long)__brk_base;
+unsigned long _brk_end = (unsigned long)__brk_base;
+
+struct boot_params boot_params;
+
+/*
+ * Machine setup..
+ */
+static struct resource data_resource = {
+	.name	= "Kernel data",
+	.start	= 0,
+	.end	= 0,
+	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
+};
+
+static struct resource code_resource = {
+	.name	= "Kernel code",
+	.start	= 0,
+	.end	= 0,
+	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
+};
+
+static struct resource bss_resource = {
+	.name	= "Kernel bss",
+	.start	= 0,
+	.end	= 0,
+	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
+};
+
+
+#ifdef CONFIG_X86_32
+/* cpu data as detected by the assembly code in head_32.S */
+struct cpuinfo_x86 new_cpu_data;
+
+/* common cpu data for all cpus */
+struct cpuinfo_x86 boot_cpu_data __read_mostly;
+EXPORT_SYMBOL(boot_cpu_data);
+
+unsigned int def_to_bigsmp;
+
+/* for MCA, but anyone else can use it if they want */
+unsigned int machine_id;
+unsigned int machine_submodel_id;
+unsigned int BIOS_revision;
+
+struct apm_info apm_info;
+EXPORT_SYMBOL(apm_info);
+
+#if defined(CONFIG_X86_SPEEDSTEP_SMI) || \
+	defined(CONFIG_X86_SPEEDSTEP_SMI_MODULE)
+struct ist_info ist_info;
+EXPORT_SYMBOL(ist_info);
+#else
+struct ist_info ist_info;
+#endif
+
+#else
+struct cpuinfo_x86 boot_cpu_data __read_mostly;
+EXPORT_SYMBOL(boot_cpu_data);
+#endif
+
+
+#if !defined(CONFIG_X86_PAE) || defined(CONFIG_X86_64)
+__visible unsigned long mmu_cr4_features __ro_after_init;
+#else
+__visible unsigned long mmu_cr4_features __ro_after_init = X86_CR4_PAE;
+#endif
+
+/* Boot loader ID and version as integers, for the benefit of proc_dointvec */
+int bootloader_type, bootloader_version;
+
+/*
+ * Setup options
+ */
+struct screen_info screen_info;
+EXPORT_SYMBOL(screen_info);
+struct edid_info edid_info;
+EXPORT_SYMBOL_GPL(edid_info);
+
+extern int root_mountflags;
+
+unsigned long saved_video_mode;
+
+#define RAMDISK_IMAGE_START_MASK	0x07FF
+#define RAMDISK_PROMPT_FLAG		0x8000
+#define RAMDISK_LOAD_FLAG		0x4000
+
+static char __initdata command_line[COMMAND_LINE_SIZE];
+#ifdef CONFIG_CMDLINE_BOOL
+static char __initdata builtin_cmdline[COMMAND_LINE_SIZE] = CONFIG_CMDLINE;
+#endif
+
+#if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
+struct edd edd;
+#ifdef CONFIG_EDD_MODULE
+EXPORT_SYMBOL(edd);
+#endif
+/**
+ * copy_edd() - Copy the BIOS EDD information
+ *              from boot_params into a safe place.
+ *
+ */
+static inline void __init copy_edd(void)
+{
+     memcpy(edd.mbr_signature, boot_params.edd_mbr_sig_buffer,
+	    sizeof(edd.mbr_signature));
+     memcpy(edd.edd_info, boot_params.eddbuf, sizeof(edd.edd_info));
+     edd.mbr_signature_nr = boot_params.edd_mbr_sig_buf_entries;
+     edd.edd_info_nr = boot_params.eddbuf_entries;
+}
+#else
+static inline void __init copy_edd(void)
+{
+}
+#endif
+
+void * __init extend_brk(size_t size, size_t align)
+{
+	size_t mask = align - 1;
+	void *ret;
+
+	BUG_ON(_brk_start == 0);
+	BUG_ON(align & mask);
+
+	_brk_end = (_brk_end + mask) & ~mask;
+	BUG_ON((char *)(_brk_end + size) > __brk_limit);
+
+	ret = (void *)_brk_end;
+	_brk_end += size;
+
+	memset(ret, 0, size);
+
+	return ret;
+}
+
+#ifdef CONFIG_X86_32
+static void __init cleanup_highmap(void)
+{
+}
+#endif
+
+static void __init reserve_brk(void)
+{
+	if (_brk_end > _brk_start)
+		memblock_reserve(__pa_symbol(_brk_start),
+				 _brk_end - _brk_start);
+
+	/* Mark brk area as locked down and no longer taking any
+	   new allocations */
+	_brk_start = 0;
+}
+
+u64 relocated_ramdisk;
+
+#ifdef CONFIG_BLK_DEV_INITRD
+
+static u64 __init get_ramdisk_image(void)
+{
+	u64 ramdisk_image = boot_params.hdr.ramdisk_image;
+
+	ramdisk_image |= (u64)boot_params.ext_ramdisk_image << 32;
+
+	return ramdisk_image;
+}
+static u64 __init get_ramdisk_size(void)
+{
+	u64 ramdisk_size = boot_params.hdr.ramdisk_size;
+
+	ramdisk_size |= (u64)boot_params.ext_ramdisk_size << 32;
+
+	return ramdisk_size;
+}
+
+static void __init relocate_initrd(void)
+{
+	/* Assume only end is not page aligned */
+	u64 ramdisk_image = get_ramdisk_image();
+	u64 ramdisk_size  = get_ramdisk_size();
+	u64 area_size     = PAGE_ALIGN(ramdisk_size);
+
+	/* We need to move the initrd down into directly mapped mem */
+	relocated_ramdisk = memblock_find_in_range(0, PFN_PHYS(max_pfn_mapped),
+						   area_size, PAGE_SIZE);
+
+	if (!relocated_ramdisk)
+		panic("Cannot find place for new RAMDISK of size %lld\n",
+		      ramdisk_size);
+
+	/* Note: this includes all the mem currently occupied by
+	   the initrd, we rely on that fact to keep the data intact. */
+	memblock_reserve(relocated_ramdisk, area_size);
+	initrd_start = relocated_ramdisk + PAGE_OFFSET;
+	initrd_end   = initrd_start + ramdisk_size;
+	printk(KERN_INFO "Allocated new RAMDISK: [mem %#010llx-%#010llx]\n",
+	       relocated_ramdisk, relocated_ramdisk + ramdisk_size - 1);
+
+	copy_from_early_mem((void *)initrd_start, ramdisk_image, ramdisk_size);
+
+	printk(KERN_INFO "Move RAMDISK from [mem %#010llx-%#010llx] to"
+		" [mem %#010llx-%#010llx]\n",
+		ramdisk_image, ramdisk_image + ramdisk_size - 1,
+		relocated_ramdisk, relocated_ramdisk + ramdisk_size - 1);
+}
+
+static void __init early_reserve_initrd(void)
+{
+	/* Assume only end is not page aligned */
+	u64 ramdisk_image = get_ramdisk_image();
+	u64 ramdisk_size  = get_ramdisk_size();
+	u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
+
+	if (!boot_params.hdr.type_of_loader ||
+	    !ramdisk_image || !ramdisk_size)
+		return;		/* No initrd provided by bootloader */
+
+	memblock_reserve(ramdisk_image, ramdisk_end - ramdisk_image);
+}
+static void __init reserve_initrd(void)
+{
+	/* Assume only end is not page aligned */
+	u64 ramdisk_image = get_ramdisk_image();
+	u64 ramdisk_size  = get_ramdisk_size();
+	u64 ramdisk_end   = PAGE_ALIGN(ramdisk_image + ramdisk_size);
+	u64 mapped_size;
+
+	if (!boot_params.hdr.type_of_loader ||
+	    !ramdisk_image || !ramdisk_size)
+		return;		/* No initrd provided by bootloader */
+
+	initrd_start = 0;
+
+	mapped_size = memblock_mem_size(max_pfn_mapped);
+	if (ramdisk_size >= (mapped_size>>1))
+		panic("initrd too large to handle, "
+		       "disabling initrd (%lld needed, %lld available)\n",
+		       ramdisk_size, mapped_size>>1);
+
+	printk(KERN_INFO "RAMDISK: [mem %#010llx-%#010llx]\n", ramdisk_image,
+			ramdisk_end - 1);
+
+	if (pfn_range_is_mapped(PFN_DOWN(ramdisk_image),
+				PFN_DOWN(ramdisk_end))) {
+		/* All are mapped, easy case */
+		initrd_start = ramdisk_image + PAGE_OFFSET;
+		initrd_end = initrd_start + ramdisk_size;
+		return;
+	}
+
+	relocate_initrd();
+
+	memblock_free(ramdisk_image, ramdisk_end - ramdisk_image);
+}
+
+#else
+static void __init early_reserve_initrd(void)
+{
+}
+static void __init reserve_initrd(void)
+{
+}
+#endif /* CONFIG_BLK_DEV_INITRD */
+
+static void __init parse_setup_data(void)
+{
+	struct setup_data *data;
+	u64 pa_data, pa_next;
+
+	pa_data = boot_params.hdr.setup_data;
+	while (pa_data) {
+		u32 data_len, data_type;
+
+		data = early_memremap(pa_data, sizeof(*data));
+		data_len = data->len + sizeof(struct setup_data);
+		data_type = data->type;
+		pa_next = data->next;
+		early_memunmap(data, sizeof(*data));
+
+		switch (data_type) {
+		case SETUP_E820_EXT:
+			e820__memory_setup_extended(pa_data, data_len);
+			break;
+		case SETUP_DTB:
+			add_dtb(pa_data);
+			break;
+		case SETUP_EFI:
+			parse_efi_setup(pa_data, data_len);
+			break;
+		default:
+			break;
+		}
+		pa_data = pa_next;
+	}
+}
+
+static void __init memblock_x86_reserve_range_setup_data(void)
+{
+	struct setup_data *data;
+	u64 pa_data;
+
+	pa_data = boot_params.hdr.setup_data;
+	while (pa_data) {
+		data = early_memremap(pa_data, sizeof(*data));
+		memblock_reserve(pa_data, sizeof(*data) + data->len);
+		pa_data = data->next;
+		early_memunmap(data, sizeof(*data));
+	}
+}
+
+/*
+ * --------- Crashkernel reservation ------------------------------
+ */
+
+#ifdef CONFIG_KEXEC_CORE
+
+/* 16M alignment for crash kernel regions */
+#define CRASH_ALIGN		(16 << 20)
+
+/*
+ * Keep the crash kernel below this limit.  On 32 bits earlier kernels
+ * would limit the kernel to the low 512 MiB due to mapping restrictions.
+ * On 64bit, old kexec-tools need to under 896MiB.
+ */
+#ifdef CONFIG_X86_32
+# define CRASH_ADDR_LOW_MAX	(512 << 20)
+# define CRASH_ADDR_HIGH_MAX	(512 << 20)
+#else
+# define CRASH_ADDR_LOW_MAX	(896UL << 20)
+# define CRASH_ADDR_HIGH_MAX	MAXMEM
+#endif
+
+static int __init reserve_crashkernel_low(void)
+{
+#ifdef CONFIG_X86_64
+	unsigned long long base, low_base = 0, low_size = 0;
+	unsigned long total_low_mem;
+	int ret;
+
+	total_low_mem = memblock_mem_size(1UL << (32 - PAGE_SHIFT));
+
+	/* crashkernel=Y,low */
+	ret = parse_crashkernel_low(boot_command_line, total_low_mem, &low_size, &base);
+	if (ret) {
+		/*
+		 * two parts from lib/swiotlb.c:
+		 * -swiotlb size: user-specified with swiotlb= or default.
+		 *
+		 * -swiotlb overflow buffer: now hardcoded to 32k. We round it
+		 * to 8M for other buffers that may need to stay low too. Also
+		 * make sure we allocate enough extra low memory so that we
+		 * don't run out of DMA buffers for 32-bit devices.
+		 */
+		low_size = max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20);
+	} else {
+		/* passed with crashkernel=0,low ? */
+		if (!low_size)
+			return 0;
+	}
+
+	low_base = memblock_find_in_range(0, 1ULL << 32, low_size, CRASH_ALIGN);
+	if (!low_base) {
+		pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n",
+		       (unsigned long)(low_size >> 20));
+		return -ENOMEM;
+	}
+
+	ret = memblock_reserve(low_base, low_size);
+	if (ret) {
+		pr_err("%s: Error reserving crashkernel low memblock.\n", __func__);
+		return ret;
+	}
+
+	pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (System low RAM: %ldMB)\n",
+		(unsigned long)(low_size >> 20),
+		(unsigned long)(low_base >> 20),
+		(unsigned long)(total_low_mem >> 20));
+
+	crashk_low_res.start = low_base;
+	crashk_low_res.end   = low_base + low_size - 1;
+	insert_resource(&iomem_resource, &crashk_low_res);
+#endif
+	return 0;
+}
+
+static void __init reserve_crashkernel(void)
+{
+	unsigned long long crash_size, crash_base, total_mem;
+	bool high = false;
+	int ret;
+
+	total_mem = memblock_phys_mem_size();
+
+	/* crashkernel=XM */
+	ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base);
+	if (ret != 0 || crash_size <= 0) {
+		/* crashkernel=X,high */
+		ret = parse_crashkernel_high(boot_command_line, total_mem,
+					     &crash_size, &crash_base);
+		if (ret != 0 || crash_size <= 0)
+			return;
+		high = true;
+	}
+
+	if (xen_pv_domain()) {
+		pr_info("Ignoring crashkernel for a Xen PV domain\n");
+		return;
+	}
+
+	/* 0 means: find the address automatically */
+	if (crash_base <= 0) {
+		/*
+		 * Set CRASH_ADDR_LOW_MAX upper bound for crash memory,
+		 * as old kexec-tools loads bzImage below that, unless
+		 * "crashkernel=size[KMG],high" is specified.
+		 */
+		crash_base = memblock_find_in_range(CRASH_ALIGN,
+						    high ? CRASH_ADDR_HIGH_MAX
+							 : CRASH_ADDR_LOW_MAX,
+						    crash_size, CRASH_ALIGN);
+		if (!crash_base) {
+			pr_info("crashkernel reservation failed - No suitable area found.\n");
+			return;
+		}
+
+	} else {
+		unsigned long long start;
+
+		start = memblock_find_in_range(crash_base,
+					       crash_base + crash_size,
+					       crash_size, 1 << 20);
+		if (start != crash_base) {
+			pr_info("crashkernel reservation failed - memory is in use.\n");
+			return;
+		}
+	}
+	ret = memblock_reserve(crash_base, crash_size);
+	if (ret) {
+		pr_err("%s: Error reserving crashkernel memblock.\n", __func__);
+		return;
+	}
+
+	if (crash_base >= (1ULL << 32) && reserve_crashkernel_low()) {
+		memblock_free(crash_base, crash_size);
+		return;
+	}
+
+	pr_info("Reserving %ldMB of memory at %ldMB for crashkernel (System RAM: %ldMB)\n",
+		(unsigned long)(crash_size >> 20),
+		(unsigned long)(crash_base >> 20),
+		(unsigned long)(total_mem >> 20));
+
+	crashk_res.start = crash_base;
+	crashk_res.end   = crash_base + crash_size - 1;
+	insert_resource(&iomem_resource, &crashk_res);
+}
+#else
+static void __init reserve_crashkernel(void)
+{
+}
+#endif
+
+static struct resource standard_io_resources[] = {
+	{ .name = "dma1", .start = 0x00, .end = 0x1f,
+		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
+	{ .name = "pic1", .start = 0x20, .end = 0x21,
+		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
+	{ .name = "timer0", .start = 0x40, .end = 0x43,
+		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
+	{ .name = "timer1", .start = 0x50, .end = 0x53,
+		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
+	{ .name = "keyboard", .start = 0x60, .end = 0x60,
+		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
+	{ .name = "keyboard", .start = 0x64, .end = 0x64,
+		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
+	{ .name = "dma page reg", .start = 0x80, .end = 0x8f,
+		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
+	{ .name = "pic2", .start = 0xa0, .end = 0xa1,
+		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
+	{ .name = "dma2", .start = 0xc0, .end = 0xdf,
+		.flags = IORESOURCE_BUSY | IORESOURCE_IO },
+	{ .name = "fpu", .start = 0xf0, .end = 0xff,
+		.flags = IORESOURCE_BUSY | IORESOURCE_IO }
+};
+
+void __init reserve_standard_io_resources(void)
+{
+	int i;
+
+	/* request I/O space for devices used on all i[345]86 PCs */
+	for (i = 0; i < ARRAY_SIZE(standard_io_resources); i++)
+		request_resource(&ioport_resource, &standard_io_resources[i]);
+
+}
+
+static __init void reserve_ibft_region(void)
+{
+	unsigned long addr, size = 0;
+
+	addr = find_ibft_region(&size);
+
+	if (size)
+		memblock_reserve(addr, size);
+}
+
+static bool __init snb_gfx_workaround_needed(void)
+{
+#ifdef CONFIG_PCI
+	int i;
+	u16 vendor, devid;
+	static const __initconst u16 snb_ids[] = {
+		0x0102,
+		0x0112,
+		0x0122,
+		0x0106,
+		0x0116,
+		0x0126,
+		0x010a,
+	};
+
+	/* Assume no if something weird is going on with PCI */
+	if (!early_pci_allowed())
+		return false;
+
+	vendor = read_pci_config_16(0, 2, 0, PCI_VENDOR_ID);
+	if (vendor != 0x8086)
+		return false;
+
+	devid = read_pci_config_16(0, 2, 0, PCI_DEVICE_ID);
+	for (i = 0; i < ARRAY_SIZE(snb_ids); i++)
+		if (devid == snb_ids[i])
+			return true;
+#endif
+
+	return false;
+}
+
+/*
+ * Sandy Bridge graphics has trouble with certain ranges, exclude
+ * them from allocation.
+ */
+static void __init trim_snb_memory(void)
+{
+	static const __initconst unsigned long bad_pages[] = {
+		0x20050000,
+		0x20110000,
+		0x20130000,
+		0x20138000,
+		0x40004000,
+	};
+	int i;
+
+	if (!snb_gfx_workaround_needed())
+		return;
+
+	printk(KERN_DEBUG "reserving inaccessible SNB gfx pages\n");
+
+	/*
+	 * Reserve all memory below the 1 MB mark that has not
+	 * already been reserved.
+	 */
+	memblock_reserve(0, 1<<20);
+	
+	for (i = 0; i < ARRAY_SIZE(bad_pages); i++) {
+		if (memblock_reserve(bad_pages[i], PAGE_SIZE))
+			printk(KERN_WARNING "failed to reserve 0x%08lx\n",
+			       bad_pages[i]);
+	}
+}
+
+/*
+ * Here we put platform-specific memory range workarounds, i.e.
+ * memory known to be corrupt or otherwise in need to be reserved on
+ * specific platforms.
+ *
+ * If this gets used more widely it could use a real dispatch mechanism.
+ */
+static void __init trim_platform_memory_ranges(void)
+{
+	trim_snb_memory();
+}
+
+static void __init trim_bios_range(void)
+{
+	/*
+	 * A special case is the first 4Kb of memory;
+	 * This is a BIOS owned area, not kernel ram, but generally
+	 * not listed as such in the E820 table.
+	 *
+	 * This typically reserves additional memory (64KiB by default)
+	 * since some BIOSes are known to corrupt low memory.  See the
+	 * Kconfig help text for X86_RESERVE_LOW.
+	 */
+	e820__range_update(0, PAGE_SIZE, E820_TYPE_RAM, E820_TYPE_RESERVED);
+
+	/*
+	 * special case: Some BIOSen report the PC BIOS
+	 * area (640->1Mb) as ram even though it is not.
+	 * take them out.
+	 */
+	e820__range_remove(BIOS_BEGIN, BIOS_END - BIOS_BEGIN, E820_TYPE_RAM, 1);
+
+	e820__update_table(e820_table);
+}
+
+/* called before trim_bios_range() to spare extra sanitize */
+static void __init e820_add_kernel_range(void)
+{
+	u64 start = __pa_symbol(_text);
+	u64 size = __pa_symbol(_end) - start;
+
+	/*
+	 * Complain if .text .data and .bss are not marked as E820_TYPE_RAM and
+	 * attempt to fix it by adding the range. We may have a confused BIOS,
+	 * or the user may have used memmap=exactmap or memmap=xxM$yyM to
+	 * exclude kernel range. If we really are running on top non-RAM,
+	 * we will crash later anyways.
+	 */
+	if (e820__mapped_all(start, start + size, E820_TYPE_RAM))
+		return;
+
+	pr_warn(".text .data .bss are not marked as E820_TYPE_RAM!\n");
+	e820__range_remove(start, size, E820_TYPE_RAM, 0);
+	e820__range_add(start, size, E820_TYPE_RAM);
+}
+
+static unsigned reserve_low = CONFIG_X86_RESERVE_LOW << 10;
+
+static int __init parse_reservelow(char *p)
+{
+	unsigned long long size;
+
+	if (!p)
+		return -EINVAL;
+
+	size = memparse(p, &p);
+
+	if (size < 4096)
+		size = 4096;
+
+	if (size > 640*1024)
+		size = 640*1024;
+
+	reserve_low = size;
+
+	return 0;
+}
+
+early_param("reservelow", parse_reservelow);
+
+static void __init trim_low_memory_range(void)
+{
+	memblock_reserve(0, ALIGN(reserve_low, PAGE_SIZE));
+}
+	
+/*
+ * Dump out kernel offset information on panic.
+ */
+static int
+dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
+{
+	if (kaslr_enabled()) {
+		pr_emerg("Kernel Offset: 0x%lx from 0x%lx (relocation range: 0x%lx-0x%lx)\n",
+			 kaslr_offset(),
+			 __START_KERNEL,
+			 __START_KERNEL_map,
+			 MODULES_VADDR-1);
+	} else {
+		pr_emerg("Kernel Offset: disabled\n");
+	}
+
+	return 0;
+}
+
+/*
+ * Determine if we were loaded by an EFI loader.  If so, then we have also been
+ * passed the efi memmap, systab, etc., so we should use these data structures
+ * for initialization.  Note, the efi init code path is determined by the
+ * global efi_enabled. This allows the same kernel image to be used on existing
+ * systems (with a traditional BIOS) as well as on EFI systems.
+ */
+/*
+ * setup_arch - architecture-specific boot-time initializations
+ *
+ * Note: On x86_64, fixmaps are ready for use even before this is called.
+ */
+
+void __init setup_arch(char **cmdline_p)
+{
+	memblock_reserve(__pa_symbol(_text),
+			 (unsigned long)__bss_stop - (unsigned long)_text);
+
+	/*
+	 * Make sure page 0 is always reserved because on systems with
+	 * L1TF its contents can be leaked to user processes.
+	 */
+	memblock_reserve(0, PAGE_SIZE);
+
+	early_reserve_initrd();
+
+	/*
+	 * At this point everything still needed from the boot loader
+	 * or BIOS or kernel text should be early reserved or marked not
+	 * RAM in e820. All other memory is free game.
+	 */
+
+#ifdef CONFIG_X86_32
+	memcpy(&boot_cpu_data, &new_cpu_data, sizeof(new_cpu_data));
+
+	/*
+	 * copy kernel address range established so far and switch
+	 * to the proper swapper page table
+	 */
+	clone_pgd_range(swapper_pg_dir     + KERNEL_PGD_BOUNDARY,
+			initial_page_table + KERNEL_PGD_BOUNDARY,
+			KERNEL_PGD_PTRS);
+
+	load_cr3(swapper_pg_dir);
+	/*
+	 * Note: Quark X1000 CPUs advertise PGE incorrectly and require
+	 * a cr3 based tlb flush, so the following __flush_tlb_all()
+	 * will not flush anything because the cpu quirk which clears
+	 * X86_FEATURE_PGE has not been invoked yet. Though due to the
+	 * load_cr3() above the TLB has been flushed already. The
+	 * quirk is invoked before subsequent calls to __flush_tlb_all()
+	 * so proper operation is guaranteed.
+	 */
+	__flush_tlb_all();
+#else
+	printk(KERN_INFO "Command line: %s\n", boot_command_line);
+	boot_cpu_data.x86_phys_bits = MAX_PHYSMEM_BITS;
+#endif
+
+	/*
+	 * If we have OLPC OFW, we might end up relocating the fixmap due to
+	 * reserve_top(), so do this before touching the ioremap area.
+	 */
+	olpc_ofw_detect();
+
+	idt_setup_early_traps();
+	early_cpu_init();
+	arch_init_ideal_nops();
+	jump_label_init();
+	early_ioremap_init();
+
+	setup_olpc_ofw_pgd();
+
+	ROOT_DEV = old_decode_dev(boot_params.hdr.root_dev);
+	screen_info = boot_params.screen_info;
+	edid_info = boot_params.edid_info;
+#ifdef CONFIG_X86_32
+	apm_info.bios = boot_params.apm_bios_info;
+	ist_info = boot_params.ist_info;
+#endif
+	saved_video_mode = boot_params.hdr.vid_mode;
+	bootloader_type = boot_params.hdr.type_of_loader;
+	if ((bootloader_type >> 4) == 0xe) {
+		bootloader_type &= 0xf;
+		bootloader_type |= (boot_params.hdr.ext_loader_type+0x10) << 4;
+	}
+	bootloader_version  = bootloader_type & 0xf;
+	bootloader_version |= boot_params.hdr.ext_loader_ver << 4;
+
+#ifdef CONFIG_BLK_DEV_RAM
+	rd_image_start = boot_params.hdr.ram_size & RAMDISK_IMAGE_START_MASK;
+	rd_prompt = ((boot_params.hdr.ram_size & RAMDISK_PROMPT_FLAG) != 0);
+	rd_doload = ((boot_params.hdr.ram_size & RAMDISK_LOAD_FLAG) != 0);
+#endif
+#ifdef CONFIG_EFI
+	if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
+		     EFI32_LOADER_SIGNATURE, 4)) {
+		set_bit(EFI_BOOT, &efi.flags);
+	} else if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
+		     EFI64_LOADER_SIGNATURE, 4)) {
+		set_bit(EFI_BOOT, &efi.flags);
+		set_bit(EFI_64BIT, &efi.flags);
+	}
+#endif
+
+	x86_init.oem.arch_setup();
+
+	iomem_resource.end = (1ULL << boot_cpu_data.x86_phys_bits) - 1;
+	e820__memory_setup();
+	parse_setup_data();
+
+	copy_edd();
+
+	if (!boot_params.hdr.root_flags)
+		root_mountflags &= ~MS_RDONLY;
+	init_mm.start_code = (unsigned long) _text;
+	init_mm.end_code = (unsigned long) _etext;
+	init_mm.end_data = (unsigned long) _edata;
+	init_mm.brk = _brk_end;
+
+	mpx_mm_init(&init_mm);
+
+	code_resource.start = __pa_symbol(_text);
+	code_resource.end = __pa_symbol(_etext)-1;
+	data_resource.start = __pa_symbol(_etext);
+	data_resource.end = __pa_symbol(_edata)-1;
+	bss_resource.start = __pa_symbol(__bss_start);
+	bss_resource.end = __pa_symbol(__bss_stop)-1;
+
+#ifdef CONFIG_CMDLINE_BOOL
+#ifdef CONFIG_CMDLINE_OVERRIDE
+	strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
+#else
+	if (builtin_cmdline[0]) {
+		/* append boot loader cmdline to builtin */
+		strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);
+		strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);
+		strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
+	}
+#endif
+#endif
+
+	strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
+	*cmdline_p = command_line;
+
+	/*
+	 * x86_configure_nx() is called before parse_early_param() to detect
+	 * whether hardware doesn't support NX (so that the early EHCI debug
+	 * console setup can safely call set_fixmap()). It may then be called
+	 * again from within noexec_setup() during parsing early parameters
+	 * to honor the respective command line option.
+	 */
+	x86_configure_nx();
+
+	parse_early_param();
+
+	if (efi_enabled(EFI_BOOT))
+		efi_memblock_x86_reserve_range();
+#ifdef CONFIG_MEMORY_HOTPLUG
+	/*
+	 * Memory used by the kernel cannot be hot-removed because Linux
+	 * cannot migrate the kernel pages. When memory hotplug is
+	 * enabled, we should prevent memblock from allocating memory
+	 * for the kernel.
+	 *
+	 * ACPI SRAT records all hotpluggable memory ranges. But before
+	 * SRAT is parsed, we don't know about it.
+	 *
+	 * The kernel image is loaded into memory at very early time. We
+	 * cannot prevent this anyway. So on NUMA system, we set any
+	 * node the kernel resides in as un-hotpluggable.
+	 *
+	 * Since on modern servers, one node could have double-digit
+	 * gigabytes memory, we can assume the memory around the kernel
+	 * image is also un-hotpluggable. So before SRAT is parsed, just
+	 * allocate memory near the kernel image to try the best to keep
+	 * the kernel away from hotpluggable memory.
+	 */
+	if (movable_node_is_enabled())
+		memblock_set_bottom_up(true);
+#endif
+
+	x86_report_nx();
+
+	/* after early param, so could get panic from serial */
+	memblock_x86_reserve_range_setup_data();
+
+	if (acpi_mps_check()) {
+#ifdef CONFIG_X86_LOCAL_APIC
+		disable_apic = 1;
+#endif
+		setup_clear_cpu_cap(X86_FEATURE_APIC);
+	}
+
+	e820__reserve_setup_data();
+	e820__finish_early_params();
+
+	if (efi_enabled(EFI_BOOT))
+		efi_init();
+
+	dmi_scan_machine();
+	dmi_memdev_walk();
+	dmi_set_dump_stack_arch_desc();
+
+	/*
+	 * VMware detection requires dmi to be available, so this
+	 * needs to be done after dmi_scan_machine(), for the boot CPU.
+	 */
+	init_hypervisor_platform();
+
+	tsc_early_init();
+	x86_init.resources.probe_roms();
+
+	/* after parse_early_param, so could debug it */
+	insert_resource(&iomem_resource, &code_resource);
+	insert_resource(&iomem_resource, &data_resource);
+	insert_resource(&iomem_resource, &bss_resource);
+
+	e820_add_kernel_range();
+	trim_bios_range();
+#ifdef CONFIG_X86_32
+	if (ppro_with_ram_bug()) {
+		e820__range_update(0x70000000ULL, 0x40000ULL, E820_TYPE_RAM,
+				  E820_TYPE_RESERVED);
+		e820__update_table(e820_table);
+		printk(KERN_INFO "fixed physical RAM map:\n");
+		e820__print_table("bad_ppro");
+	}
+#else
+	early_gart_iommu_check();
+#endif
+
+	/*
+	 * partially used pages are not usable - thus
+	 * we are rounding upwards:
+	 */
+	max_pfn = e820__end_of_ram_pfn();
+
+	/* update e820 for memory not covered by WB MTRRs */
+	mtrr_bp_init();
+	if (mtrr_trim_uncached_memory(max_pfn))
+		max_pfn = e820__end_of_ram_pfn();
+
+	max_possible_pfn = max_pfn;
+
+	/*
+	 * This call is required when the CPU does not support PAT. If
+	 * mtrr_bp_init() invoked it already via pat_init() the call has no
+	 * effect.
+	 */
+	init_cache_modes();
+
+	/*
+	 * Define random base addresses for memory sections after max_pfn is
+	 * defined and before each memory section base is used.
+	 */
+	kernel_randomize_memory();
+
+#ifdef CONFIG_X86_32
+	/* max_low_pfn get updated here */
+	find_low_pfn_range();
+#else
+	check_x2apic();
+
+	/* How many end-of-memory variables you have, grandma! */
+	/* need this before calling reserve_initrd */
+	if (max_pfn > (1UL<<(32 - PAGE_SHIFT)))
+		max_low_pfn = e820__end_of_low_ram_pfn();
+	else
+		max_low_pfn = max_pfn;
+
+	high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
+#endif
+
+	/*
+	 * Find and reserve possible boot-time SMP configuration:
+	 */
+	find_smp_config();
+
+	reserve_ibft_region();
+
+	early_alloc_pgt_buf();
+
+	/*
+	 * Need to conclude brk, before e820__memblock_setup()
+	 *  it could use memblock_find_in_range, could overlap with
+	 *  brk area.
+	 */
+	reserve_brk();
+
+	cleanup_highmap();
+
+	memblock_set_current_limit(ISA_END_ADDRESS);
+	e820__memblock_setup();
+
+	reserve_bios_regions();
+
+	if (efi_enabled(EFI_MEMMAP)) {
+		efi_fake_memmap();
+		efi_find_mirror();
+		efi_esrt_init();
+
+		/*
+		 * The EFI specification says that boot service code won't be
+		 * called after ExitBootServices(). This is, in fact, a lie.
+		 */
+		efi_reserve_boot_services();
+	}
+
+	/* preallocate 4k for mptable mpc */
+	e820__memblock_alloc_reserved_mpc_new();
+
+#ifdef CONFIG_X86_CHECK_BIOS_CORRUPTION
+	setup_bios_corruption_check();
+#endif
+
+#ifdef CONFIG_X86_32
+	printk(KERN_DEBUG "initial memory mapped: [mem 0x00000000-%#010lx]\n",
+			(max_pfn_mapped<<PAGE_SHIFT) - 1);
+#endif
+
+	reserve_real_mode();
+
+	trim_platform_memory_ranges();
+	trim_low_memory_range();
+
+	init_mem_mapping();
+
+	idt_setup_early_pf();
+
+	/*
+	 * Update mmu_cr4_features (and, indirectly, trampoline_cr4_features)
+	 * with the current CR4 value.  This may not be necessary, but
+	 * auditing all the early-boot CR4 manipulation would be needed to
+	 * rule it out.
+	 *
+	 * Mask off features that don't work outside long mode (just
+	 * PCIDE for now).
+	 */
+	mmu_cr4_features = __read_cr4() & ~X86_CR4_PCIDE;
+
+	memblock_set_current_limit(get_max_mapped());
+
+	/*
+	 * NOTE: On x86-32, only from this point on, fixmaps are ready for use.
+	 */
+
+#ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
+	if (init_ohci1394_dma_early)
+		init_ohci1394_dma_on_all_controllers();
+#endif
+	/* Allocate bigger log buffer */
+	setup_log_buf(1);
+
+	if (efi_enabled(EFI_BOOT)) {
+		switch (boot_params.secure_boot) {
+		case efi_secureboot_mode_disabled:
+			pr_info("Secure boot disabled\n");
+			break;
+		case efi_secureboot_mode_enabled:
+			pr_info("Secure boot enabled\n");
+			break;
+		default:
+			pr_info("Secure boot could not be determined\n");
+			break;
+		}
+	}
+
+	reserve_initrd();
+
+	acpi_table_upgrade();
+
+	vsmp_init();
+
+	io_delay_init();
+
+	early_platform_quirks();
+
+	/*
+	 * Parse the ACPI tables for possible boot-time SMP configuration.
+	 */
+	acpi_boot_table_init();
+
+	early_acpi_boot_init();
+
+	initmem_init();
+	dma_contiguous_reserve(max_pfn_mapped << PAGE_SHIFT);
+
+	/*
+	 * Reserve memory for crash kernel after SRAT is parsed so that it
+	 * won't consume hotpluggable memory.
+	 */
+	reserve_crashkernel();
+
+	memblock_find_dma_reserve();
+
+	if (!early_xdbc_setup_hardware())
+		early_xdbc_register_console();
+
+	x86_init.paging.pagetable_init();
+
+	kasan_init();
+
+	/*
+	 * Sync back kernel address range.
+	 *
+	 * FIXME: Can the later sync in setup_cpu_entry_areas() replace
+	 * this call?
+	 */
+	sync_initial_page_table();
+
+	tboot_probe();
+
+	map_vsyscall();
+
+	generic_apic_probe();
+
+	early_quirks();
+
+	/*
+	 * Read APIC and some other early information from ACPI tables.
+	 */
+	acpi_boot_init();
+	sfi_init();
+	x86_dtb_init();
+
+	/*
+	 * get boot-time SMP configuration:
+	 */
+	get_smp_config();
+
+	/*
+	 * Systems w/o ACPI and mptables might not have it mapped the local
+	 * APIC yet, but prefill_possible_map() might need to access it.
+	 */
+	init_apic_mappings();
+
+	prefill_possible_map();
+
+	init_cpu_to_node();
+
+	io_apic_init_mappings();
+
+	x86_init.hyper.guest_late_init();
+
+	e820__reserve_resources();
+	e820__register_nosave_regions(max_low_pfn);
+
+	x86_init.resources.reserve_resources();
+
+	e820__setup_pci_gap();
+
+#ifdef CONFIG_VT
+#if defined(CONFIG_VGA_CONSOLE)
+	if (!efi_enabled(EFI_BOOT) || (efi_mem_type(0xa0000) != EFI_CONVENTIONAL_MEMORY))
+		conswitchp = &vga_con;
+#elif defined(CONFIG_DUMMY_CONSOLE)
+	conswitchp = &dummy_con;
+#endif
+#endif
+	x86_init.oem.banner();
+
+	x86_init.timers.wallclock_init();
+
+	mcheck_init();
+
+	register_refined_jiffies(CLOCK_TICK_RATE);
+
+#ifdef CONFIG_EFI
+	if (efi_enabled(EFI_BOOT))
+		efi_apply_memmap_quirks();
+#endif
+
+	unwind_init();
+}
+
+#ifdef CONFIG_X86_32
+
+static struct resource video_ram_resource = {
+	.name	= "Video RAM area",
+	.start	= 0xa0000,
+	.end	= 0xbffff,
+	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM
+};
+
+void __init i386_reserve_resources(void)
+{
+	request_resource(&iomem_resource, &video_ram_resource);
+	reserve_standard_io_resources();
+}
+
+#endif /* CONFIG_X86_32 */
+
+static struct notifier_block kernel_offset_notifier = {
+	.notifier_call = dump_kernel_offset
+};
+
+static int __init register_kernel_offset_dumper(void)
+{
+	atomic_notifier_chain_register(&panic_notifier_list,
+					&kernel_offset_notifier);
+	return 0;
+}
+__initcall(register_kernel_offset_dumper);