x86_64: move mm

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 750 insertions, 0 deletions

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
new file mode 100644
index 000000000000..458893b376f8
--- /dev/null
+++ b/arch/x86/mm/init_64.c
@@ -0,0 +1,750 @@
+/*
+ *  linux/arch/x86_64/mm/init.c
+ *
+ *  Copyright (C) 1995  Linus Torvalds
+ *  Copyright (C) 2000  Pavel Machek <pavel@suse.cz>
+ *  Copyright (C) 2002,2003 Andi Kleen <ak@suse.de>
+ */
+
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/smp.h>
+#include <linux/init.h>
+#include <linux/pagemap.h>
+#include <linux/bootmem.h>
+#include <linux/proc_fs.h>
+#include <linux/pci.h>
+#include <linux/pfn.h>
+#include <linux/poison.h>
+#include <linux/dma-mapping.h>
+#include <linux/module.h>
+#include <linux/memory_hotplug.h>
+#include <linux/nmi.h>
+
+#include <asm/processor.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/dma.h>
+#include <asm/fixmap.h>
+#include <asm/e820.h>
+#include <asm/apic.h>
+#include <asm/tlb.h>
+#include <asm/mmu_context.h>
+#include <asm/proto.h>
+#include <asm/smp.h>
+#include <asm/sections.h>
+
+#ifndef Dprintk
+#define Dprintk(x...)
+#endif
+
+const struct dma_mapping_ops* dma_ops;
+EXPORT_SYMBOL(dma_ops);
+
+static unsigned long dma_reserve __initdata;
+
+DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
+
+/*
+ * NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
+ * physical space so we can cache the place of the first one and move
+ * around without checking the pgd every time.
+ */
+
+void show_mem(void)
+{
+	long i, total = 0, reserved = 0;
+	long shared = 0, cached = 0;
+	pg_data_t *pgdat;
+	struct page *page;
+
+	printk(KERN_INFO "Mem-info:\n");
+	show_free_areas();
+	printk(KERN_INFO "Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
+
+	for_each_online_pgdat(pgdat) {
+               for (i = 0; i < pgdat->node_spanned_pages; ++i) {
+			/* this loop can take a while with 256 GB and 4k pages
+			   so update the NMI watchdog */
+			if (unlikely(i % MAX_ORDER_NR_PAGES == 0)) {
+				touch_nmi_watchdog();
+			}
+			if (!pfn_valid(pgdat->node_start_pfn + i))
+				continue;
+			page = pfn_to_page(pgdat->node_start_pfn + i);
+			total++;
+			if (PageReserved(page))
+				reserved++;
+			else if (PageSwapCache(page))
+				cached++;
+			else if (page_count(page))
+				shared += page_count(page) - 1;
+               }
+	}
+	printk(KERN_INFO "%lu pages of RAM\n", total);
+	printk(KERN_INFO "%lu reserved pages\n",reserved);
+	printk(KERN_INFO "%lu pages shared\n",shared);
+	printk(KERN_INFO "%lu pages swap cached\n",cached);
+}
+
+int after_bootmem;
+
+static __init void *spp_getpage(void)
+{ 
+	void *ptr;
+	if (after_bootmem)
+		ptr = (void *) get_zeroed_page(GFP_ATOMIC); 
+	else
+		ptr = alloc_bootmem_pages(PAGE_SIZE);
+	if (!ptr || ((unsigned long)ptr & ~PAGE_MASK))
+		panic("set_pte_phys: cannot allocate page data %s\n", after_bootmem?"after bootmem":"");
+
+	Dprintk("spp_getpage %p\n", ptr);
+	return ptr;
+} 
+
+static __init void set_pte_phys(unsigned long vaddr,
+			 unsigned long phys, pgprot_t prot)
+{
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte, new_pte;
+
+	Dprintk("set_pte_phys %lx to %lx\n", vaddr, phys);
+
+	pgd = pgd_offset_k(vaddr);
+	if (pgd_none(*pgd)) {
+		printk("PGD FIXMAP MISSING, it should be setup in head.S!\n");
+		return;
+	}
+	pud = pud_offset(pgd, vaddr);
+	if (pud_none(*pud)) {
+		pmd = (pmd_t *) spp_getpage(); 
+		set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | _PAGE_USER));
+		if (pmd != pmd_offset(pud, 0)) {
+			printk("PAGETABLE BUG #01! %p <-> %p\n", pmd, pmd_offset(pud,0));
+			return;
+		}
+	}
+	pmd = pmd_offset(pud, vaddr);
+	if (pmd_none(*pmd)) {
+		pte = (pte_t *) spp_getpage();
+		set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER));
+		if (pte != pte_offset_kernel(pmd, 0)) {
+			printk("PAGETABLE BUG #02!\n");
+			return;
+		}
+	}
+	new_pte = pfn_pte(phys >> PAGE_SHIFT, prot);
+
+	pte = pte_offset_kernel(pmd, vaddr);
+	if (!pte_none(*pte) &&
+	    pte_val(*pte) != (pte_val(new_pte) & __supported_pte_mask))
+		pte_ERROR(*pte);
+	set_pte(pte, new_pte);
+
+	/*
+	 * It's enough to flush this one mapping.
+	 * (PGE mappings get flushed as well)
+	 */
+	__flush_tlb_one(vaddr);
+}
+
+/* NOTE: this is meant to be run only at boot */
+void __init 
+__set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
+{
+	unsigned long address = __fix_to_virt(idx);
+
+	if (idx >= __end_of_fixed_addresses) {
+		printk("Invalid __set_fixmap\n");
+		return;
+	}
+	set_pte_phys(address, phys, prot);
+}
+
+unsigned long __meminitdata table_start, table_end;
+
+static __meminit void *alloc_low_page(unsigned long *phys)
+{ 
+	unsigned long pfn = table_end++;
+	void *adr;
+
+	if (after_bootmem) {
+		adr = (void *)get_zeroed_page(GFP_ATOMIC);
+		*phys = __pa(adr);
+		return adr;
+	}
+
+	if (pfn >= end_pfn) 
+		panic("alloc_low_page: ran out of memory"); 
+
+	adr = early_ioremap(pfn * PAGE_SIZE, PAGE_SIZE);
+	memset(adr, 0, PAGE_SIZE);
+	*phys  = pfn * PAGE_SIZE;
+	return adr;
+}
+
+static __meminit void unmap_low_page(void *adr)
+{ 
+
+	if (after_bootmem)
+		return;
+
+	early_iounmap(adr, PAGE_SIZE);
+} 
+
+/* Must run before zap_low_mappings */
+__meminit void *early_ioremap(unsigned long addr, unsigned long size)
+{
+	unsigned long vaddr;
+	pmd_t *pmd, *last_pmd;
+	int i, pmds;
+
+	pmds = ((addr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE;
+	vaddr = __START_KERNEL_map;
+	pmd = level2_kernel_pgt;
+	last_pmd = level2_kernel_pgt + PTRS_PER_PMD - 1;
+	for (; pmd <= last_pmd; pmd++, vaddr += PMD_SIZE) {
+		for (i = 0; i < pmds; i++) {
+			if (pmd_present(pmd[i]))
+				goto next;
+		}
+		vaddr += addr & ~PMD_MASK;
+		addr &= PMD_MASK;
+		for (i = 0; i < pmds; i++, addr += PMD_SIZE)
+			set_pmd(pmd + i,__pmd(addr | _KERNPG_TABLE | _PAGE_PSE));
+		__flush_tlb();
+		return (void *)vaddr;
+	next:
+		;
+	}
+	printk("early_ioremap(0x%lx, %lu) failed\n", addr, size);
+	return NULL;
+}
+
+/* To avoid virtual aliases later */
+__meminit void early_iounmap(void *addr, unsigned long size)
+{
+	unsigned long vaddr;
+	pmd_t *pmd;
+	int i, pmds;
+
+	vaddr = (unsigned long)addr;
+	pmds = ((vaddr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE;
+	pmd = level2_kernel_pgt + pmd_index(vaddr);
+	for (i = 0; i < pmds; i++)
+		pmd_clear(pmd + i);
+	__flush_tlb();
+}
+
+static void __meminit
+phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end)
+{
+	int i = pmd_index(address);
+
+	for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
+		unsigned long entry;
+		pmd_t *pmd = pmd_page + pmd_index(address);
+
+		if (address >= end) {
+			if (!after_bootmem)
+				for (; i < PTRS_PER_PMD; i++, pmd++)
+					set_pmd(pmd, __pmd(0));
+			break;
+		}
+
+		if (pmd_val(*pmd))
+			continue;
+
+		entry = _PAGE_NX|_PAGE_PSE|_KERNPG_TABLE|_PAGE_GLOBAL|address;
+		entry &= __supported_pte_mask;
+		set_pmd(pmd, __pmd(entry));
+	}
+}
+
+static void __meminit
+phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end)
+{
+	pmd_t *pmd = pmd_offset(pud,0);
+	spin_lock(&init_mm.page_table_lock);
+	phys_pmd_init(pmd, address, end);
+	spin_unlock(&init_mm.page_table_lock);
+	__flush_tlb_all();
+}
+
+static void __meminit phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end)
+{ 
+	int i = pud_index(addr);
+
+
+	for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE ) {
+		unsigned long pmd_phys;
+		pud_t *pud = pud_page + pud_index(addr);
+		pmd_t *pmd;
+
+		if (addr >= end)
+			break;
+
+		if (!after_bootmem && !e820_any_mapped(addr,addr+PUD_SIZE,0)) {
+			set_pud(pud, __pud(0)); 
+			continue;
+		} 
+
+		if (pud_val(*pud)) {
+			phys_pmd_update(pud, addr, end);
+			continue;
+		}
+
+		pmd = alloc_low_page(&pmd_phys);
+		spin_lock(&init_mm.page_table_lock);
+		set_pud(pud, __pud(pmd_phys | _KERNPG_TABLE));
+		phys_pmd_init(pmd, addr, end);
+		spin_unlock(&init_mm.page_table_lock);
+		unmap_low_page(pmd);
+	}
+	__flush_tlb();
+} 
+
+static void __init find_early_table_space(unsigned long end)
+{
+	unsigned long puds, pmds, tables, start;
+
+	puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
+	pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
+	tables = round_up(puds * sizeof(pud_t), PAGE_SIZE) +
+		 round_up(pmds * sizeof(pmd_t), PAGE_SIZE);
+
+ 	/* RED-PEN putting page tables only on node 0 could
+ 	   cause a hotspot and fill up ZONE_DMA. The page tables
+ 	   need roughly 0.5KB per GB. */
+ 	start = 0x8000;
+ 	table_start = find_e820_area(start, end, tables);
+	if (table_start == -1UL)
+		panic("Cannot find space for the kernel page tables");
+
+	table_start >>= PAGE_SHIFT;
+	table_end = table_start;
+
+	early_printk("kernel direct mapping tables up to %lx @ %lx-%lx\n",
+		end, table_start << PAGE_SHIFT,
+		(table_start << PAGE_SHIFT) + tables);
+}
+
+/* Setup the direct mapping of the physical memory at PAGE_OFFSET.
+   This runs before bootmem is initialized and gets pages directly from the 
+   physical memory. To access them they are temporarily mapped. */
+void __meminit init_memory_mapping(unsigned long start, unsigned long end)
+{ 
+	unsigned long next; 
+
+	Dprintk("init_memory_mapping\n");
+
+	/* 
+	 * Find space for the kernel direct mapping tables.
+	 * Later we should allocate these tables in the local node of the memory
+	 * mapped.  Unfortunately this is done currently before the nodes are 
+	 * discovered.
+	 */
+	if (!after_bootmem)
+		find_early_table_space(end);
+
+	start = (unsigned long)__va(start);
+	end = (unsigned long)__va(end);
+
+	for (; start < end; start = next) {
+		unsigned long pud_phys; 
+		pgd_t *pgd = pgd_offset_k(start);
+		pud_t *pud;
+
+		if (after_bootmem)
+			pud = pud_offset(pgd, start & PGDIR_MASK);
+		else
+			pud = alloc_low_page(&pud_phys);
+
+		next = start + PGDIR_SIZE;
+		if (next > end) 
+			next = end; 
+		phys_pud_init(pud, __pa(start), __pa(next));
+		if (!after_bootmem)
+			set_pgd(pgd_offset_k(start), mk_kernel_pgd(pud_phys));
+		unmap_low_page(pud);
+	} 
+
+	if (!after_bootmem)
+		mmu_cr4_features = read_cr4();
+	__flush_tlb_all();
+}
+
+#ifndef CONFIG_NUMA
+void __init paging_init(void)
+{
+	unsigned long max_zone_pfns[MAX_NR_ZONES];
+	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
+	max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
+	max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
+	max_zone_pfns[ZONE_NORMAL] = end_pfn;
+
+	memory_present(0, 0, end_pfn);
+	sparse_init();
+	free_area_init_nodes(max_zone_pfns);
+}
+#endif
+
+/* Unmap a kernel mapping if it exists. This is useful to avoid prefetches
+   from the CPU leading to inconsistent cache lines. address and size
+   must be aligned to 2MB boundaries. 
+   Does nothing when the mapping doesn't exist. */
+void __init clear_kernel_mapping(unsigned long address, unsigned long size) 
+{
+	unsigned long end = address + size;
+
+	BUG_ON(address & ~LARGE_PAGE_MASK);
+	BUG_ON(size & ~LARGE_PAGE_MASK); 
+	
+	for (; address < end; address += LARGE_PAGE_SIZE) { 
+		pgd_t *pgd = pgd_offset_k(address);
+		pud_t *pud;
+		pmd_t *pmd;
+		if (pgd_none(*pgd))
+			continue;
+		pud = pud_offset(pgd, address);
+		if (pud_none(*pud))
+			continue; 
+		pmd = pmd_offset(pud, address);
+		if (!pmd || pmd_none(*pmd))
+			continue; 
+		if (0 == (pmd_val(*pmd) & _PAGE_PSE)) { 
+			/* Could handle this, but it should not happen currently. */
+			printk(KERN_ERR 
+	       "clear_kernel_mapping: mapping has been split. will leak memory\n"); 
+			pmd_ERROR(*pmd); 
+		}
+		set_pmd(pmd, __pmd(0)); 		
+	}
+	__flush_tlb_all();
+} 
+
+/*
+ * Memory hotplug specific functions
+ */
+void online_page(struct page *page)
+{
+	ClearPageReserved(page);
+	init_page_count(page);
+	__free_page(page);
+	totalram_pages++;
+	num_physpages++;
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+/*
+ * Memory is added always to NORMAL zone. This means you will never get
+ * additional DMA/DMA32 memory.
+ */
+int arch_add_memory(int nid, u64 start, u64 size)
+{
+	struct pglist_data *pgdat = NODE_DATA(nid);
+	struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
+	unsigned long start_pfn = start >> PAGE_SHIFT;
+	unsigned long nr_pages = size >> PAGE_SHIFT;
+	int ret;
+
+	init_memory_mapping(start, (start + size -1));
+
+	ret = __add_pages(zone, start_pfn, nr_pages);
+	if (ret)
+		goto error;
+
+	return ret;
+error:
+	printk("%s: Problem encountered in __add_pages!\n", __func__);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(arch_add_memory);
+
+int remove_memory(u64 start, u64 size)
+{
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(remove_memory);
+
+#if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
+int memory_add_physaddr_to_nid(u64 start)
+{
+	return 0;
+}
+EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
+#endif
+
+#endif /* CONFIG_MEMORY_HOTPLUG */
+
+#ifdef CONFIG_MEMORY_HOTPLUG_RESERVE
+/*
+ * Memory Hotadd without sparsemem. The mem_maps have been allocated in advance,
+ * just online the pages.
+ */
+int __add_pages(struct zone *z, unsigned long start_pfn, unsigned long nr_pages)
+{
+	int err = -EIO;
+	unsigned long pfn;
+	unsigned long total = 0, mem = 0;
+	for (pfn = start_pfn; pfn < start_pfn + nr_pages; pfn++) {
+		if (pfn_valid(pfn)) {
+			online_page(pfn_to_page(pfn));
+			err = 0;
+			mem++;
+		}
+		total++;
+	}
+	if (!err) {
+		z->spanned_pages += total;
+		z->present_pages += mem;
+		z->zone_pgdat->node_spanned_pages += total;
+		z->zone_pgdat->node_present_pages += mem;
+	}
+	return err;
+}
+#endif
+
+static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel, kcore_modules,
+			 kcore_vsyscall;
+
+void __init mem_init(void)
+{
+	long codesize, reservedpages, datasize, initsize;
+
+	pci_iommu_alloc();
+
+	/* clear the zero-page */
+	memset(empty_zero_page, 0, PAGE_SIZE);
+
+	reservedpages = 0;
+
+	/* this will put all low memory onto the freelists */
+#ifdef CONFIG_NUMA
+	totalram_pages = numa_free_all_bootmem();
+#else
+	totalram_pages = free_all_bootmem();
+#endif
+	reservedpages = end_pfn - totalram_pages -
+					absent_pages_in_range(0, end_pfn);
+
+	after_bootmem = 1;
+
+	codesize =  (unsigned long) &_etext - (unsigned long) &_text;
+	datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
+	initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
+
+	/* Register memory areas for /proc/kcore */
+	kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT); 
+	kclist_add(&kcore_vmalloc, (void *)VMALLOC_START, 
+		   VMALLOC_END-VMALLOC_START);
+	kclist_add(&kcore_kernel, &_stext, _end - _stext);
+	kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN);
+	kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START, 
+				 VSYSCALL_END - VSYSCALL_START);
+
+	printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
+		(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
+		end_pfn << (PAGE_SHIFT-10),
+		codesize >> 10,
+		reservedpages << (PAGE_SHIFT-10),
+		datasize >> 10,
+		initsize >> 10);
+}
+
+void free_init_pages(char *what, unsigned long begin, unsigned long end)
+{
+	unsigned long addr;
+
+	if (begin >= end)
+		return;
+
+	printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
+	for (addr = begin; addr < end; addr += PAGE_SIZE) {
+		ClearPageReserved(virt_to_page(addr));
+		init_page_count(virt_to_page(addr));
+		memset((void *)(addr & ~(PAGE_SIZE-1)),
+			POISON_FREE_INITMEM, PAGE_SIZE);
+		if (addr >= __START_KERNEL_map)
+			change_page_attr_addr(addr, 1, __pgprot(0));
+		free_page(addr);
+		totalram_pages++;
+	}
+	if (addr > __START_KERNEL_map)
+		global_flush_tlb();
+}
+
+void free_initmem(void)
+{
+	free_init_pages("unused kernel memory",
+			(unsigned long)(&__init_begin),
+			(unsigned long)(&__init_end));
+}
+
+#ifdef CONFIG_DEBUG_RODATA
+
+void mark_rodata_ro(void)
+{
+	unsigned long start = (unsigned long)_stext, end;
+
+#ifdef CONFIG_HOTPLUG_CPU
+	/* It must still be possible to apply SMP alternatives. */
+	if (num_possible_cpus() > 1)
+		start = (unsigned long)_etext;
+#endif
+
+#ifdef CONFIG_KPROBES
+	start = (unsigned long)__start_rodata;
+#endif
+	
+	end = (unsigned long)__end_rodata;
+	start = (start + PAGE_SIZE - 1) & PAGE_MASK;
+	end &= PAGE_MASK;
+	if (end <= start)
+		return;
+
+	change_page_attr_addr(start, (end - start) >> PAGE_SHIFT, PAGE_KERNEL_RO);
+
+	printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
+	       (end - start) >> 10);
+
+	/*
+	 * change_page_attr_addr() requires a global_flush_tlb() call after it.
+	 * We do this after the printk so that if something went wrong in the
+	 * change, the printk gets out at least to give a better debug hint
+	 * of who is the culprit.
+	 */
+	global_flush_tlb();
+}
+#endif
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void free_initrd_mem(unsigned long start, unsigned long end)
+{
+	free_init_pages("initrd memory", start, end);
+}
+#endif
+
+void __init reserve_bootmem_generic(unsigned long phys, unsigned len) 
+{ 
+#ifdef CONFIG_NUMA
+	int nid = phys_to_nid(phys);
+#endif
+	unsigned long pfn = phys >> PAGE_SHIFT;
+	if (pfn >= end_pfn) {
+		/* This can happen with kdump kernels when accessing firmware
+		   tables. */
+		if (pfn < end_pfn_map)
+			return;
+		printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %u\n",
+				phys, len);
+		return;
+	}
+
+	/* Should check here against the e820 map to avoid double free */
+#ifdef CONFIG_NUMA
+  	reserve_bootmem_node(NODE_DATA(nid), phys, len);
+#else       		
+	reserve_bootmem(phys, len);    
+#endif
+	if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
+		dma_reserve += len / PAGE_SIZE;
+		set_dma_reserve(dma_reserve);
+	}
+}
+
+int kern_addr_valid(unsigned long addr) 
+{ 
+	unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
+       pgd_t *pgd;
+       pud_t *pud;
+       pmd_t *pmd;
+       pte_t *pte;
+
+	if (above != 0 && above != -1UL)
+		return 0; 
+	
+	pgd = pgd_offset_k(addr);
+	if (pgd_none(*pgd))
+		return 0;
+
+	pud = pud_offset(pgd, addr);
+	if (pud_none(*pud))
+		return 0; 
+
+	pmd = pmd_offset(pud, addr);
+	if (pmd_none(*pmd))
+		return 0;
+	if (pmd_large(*pmd))
+		return pfn_valid(pmd_pfn(*pmd));
+
+	pte = pte_offset_kernel(pmd, addr);
+	if (pte_none(*pte))
+		return 0;
+	return pfn_valid(pte_pfn(*pte));
+}
+
+/* A pseudo VMA to allow ptrace access for the vsyscall page.  This only
+   covers the 64bit vsyscall page now. 32bit has a real VMA now and does
+   not need special handling anymore. */
+
+static struct vm_area_struct gate_vma = {
+	.vm_start = VSYSCALL_START,
+	.vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES << PAGE_SHIFT),
+	.vm_page_prot = PAGE_READONLY_EXEC,
+	.vm_flags = VM_READ | VM_EXEC
+};
+
+struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
+{
+#ifdef CONFIG_IA32_EMULATION
+	if (test_tsk_thread_flag(tsk, TIF_IA32))
+		return NULL;
+#endif
+	return &gate_vma;
+}
+
+int in_gate_area(struct task_struct *task, unsigned long addr)
+{
+	struct vm_area_struct *vma = get_gate_vma(task);
+	if (!vma)
+		return 0;
+	return (addr >= vma->vm_start) && (addr < vma->vm_end);
+}
+
+/* Use this when you have no reliable task/vma, typically from interrupt
+ * context.  It is less reliable than using the task's vma and may give
+ * false positives.
+ */
+int in_gate_area_no_task(unsigned long addr)
+{
+	return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
+}
+
+void * __init alloc_bootmem_high_node(pg_data_t *pgdat, unsigned long size)
+{
+	return __alloc_bootmem_core(pgdat->bdata, size,
+			SMP_CACHE_BYTES, (4UL*1024*1024*1024), 0);
+}
+
+const char *arch_vma_name(struct vm_area_struct *vma)
+{
+	if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
+		return "[vdso]";
+	if (vma == &gate_vma)
+		return "[vsyscall]";
+	return NULL;
+}