1 files changed, 750 insertions, 0 deletions

diff --git a/arch/x86_64/mm/init_64.c b/arch/x86_64/mm/init_64.c
new file mode 100644
index 000000000000..458893b376f8
--- /dev/null
+++ b/arch/x86_64/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;
+}