5 files changed, 49 insertions, 0 deletions

diff --git a/Documentation/x86_64/mm.txt b/Documentation/x86_64/mm.txt
index f42798ed1c54..b89b6d2bebfa 100644
--- a/Documentation/x86_64/mm.txt
+++ b/Documentation/x86_64/mm.txt
@@ -9,6 +9,7 @@ ffff800000000000 - ffff80ffffffffff (=40 bits) guard hole
 ffff810000000000 - ffffc0ffffffffff (=46 bits) direct mapping of all phys. memory
 ffffc10000000000 - ffffc1ffffffffff (=40 bits) hole
 ffffc20000000000 - ffffe1ffffffffff (=45 bits) vmalloc/ioremap space
+ffffe20000000000 - ffffe2ffffffffff (=40 bits) virtual memory map (1TB)
 ... unused hole ...
 ffffffff80000000 - ffffffff82800000 (=40 MB)   kernel text mapping, from phys 0
 ... unused hole ...
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 458893b376f8..7d4fc633a9c9 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -748,3 +748,48 @@ const char *arch_vma_name(struct vm_area_struct *vma)
                 return "[vsyscall]";
         return NULL;
 }
+
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+/*
+ * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
+ */
+int __meminit vmemmap_populate(struct page *start_page,
+                                                unsigned long size, int node)
+{
+        unsigned long addr = (unsigned long)start_page;
+        unsigned long end = (unsigned long)(start_page + size);
+        unsigned long next;
+        pgd_t *pgd;
+        pud_t *pud;
+        pmd_t *pmd;
+
+        for (; addr < end; addr = next) {
+                next = pmd_addr_end(addr, end);
+
+                pgd = vmemmap_pgd_populate(addr, node);
+                if (!pgd)
+                        return -ENOMEM;
+                pud = vmemmap_pud_populate(pgd, addr, node);
+                if (!pud)
+                        return -ENOMEM;
+
+                pmd = pmd_offset(pud, addr);
+                if (pmd_none(*pmd)) {
+                        pte_t entry;
+                        void *p = vmemmap_alloc_block(PMD_SIZE, node);
+                        if (!p)
+                                return -ENOMEM;
+
+                        entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL);
+                        mk_pte_huge(entry);
+                        set_pmd(pmd, __pmd(pte_val(entry)));
+
+                        printk(KERN_DEBUG " [%lx-%lx] PMD ->%p on node %d\n",
+                                addr, addr + PMD_SIZE - 1, p, node);
+                } else
+                        vmemmap_verify((pte_t *)pmd, node, addr, next);
+        }
+
+        return 0;
+}
+#endif
diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index cf013cb85ea4..8c83dbe4c4d0 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -409,6 +409,7 @@ config ARCH_DISCONTIGMEM_DEFAULT
 config ARCH_SPARSEMEM_ENABLE
         def_bool y
         depends on (NUMA || EXPERIMENTAL)
+        select SPARSEMEM_VMEMMAP_ENABLE
 
 config ARCH_MEMORY_PROBE
         def_bool y
diff --git a/include/asm-x86/page_64.h b/include/asm-x86/page_64.h
index 88adf1afb0a2..c3b52bcb171e 100644
--- a/include/asm-x86/page_64.h
+++ b/include/asm-x86/page_64.h
@@ -134,6 +134,7 @@ extern unsigned long __phys_addr(unsigned long);
          VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
 
 #define __HAVE_ARCH_GATE_AREA 1 
+#define vmemmap ((struct page *)VMEMMAP_START)
 
 #include <asm-generic/memory_model.h>
 #include <asm-generic/page.h>
diff --git a/include/asm-x86/pgtable_64.h b/include/asm-x86/pgtable_64.h
index 57dd6b3107ea..a79f5355e3b0 100644
--- a/include/asm-x86/pgtable_64.h
+++ b/include/asm-x86/pgtable_64.h
@@ -137,6 +137,7 @@ static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, unsigned long
 #define MAXMEM           _AC(0x3fffffffffff, UL)
 #define VMALLOC_START    _AC(0xffffc20000000000, UL)
 #define VMALLOC_END      _AC(0xffffe1ffffffffff, UL)
+#define VMEMMAP_START    _AC(0xffffe20000000000, UL)
 #define MODULES_VADDR    _AC(0xffffffff88000000, UL)
 #define MODULES_END      _AC(0xfffffffffff00000, UL)
 #define MODULES_LEN   (MODULES_END - MODULES_VADDR)