4/5 in support of hot-add memory x86_64 fix kernel mapping code

diff -urN orig/arch/x86_64/mm/init.c work/arch/x86_64/mm/init.c
@@ -252,9 +252,11 @@
 static void __meminit
 phys_pmd_init(pmd_t *pmd, unsigned long address, unsigned long end)
 {
-	int i;
+	int i = pmd_index(address);
 
-	for (i = 0; i < PTRS_PER_PMD; pmd++, i++, address += PMD_SIZE) {
+	pmd = pmd + i;
+
+	for (; i < PTRS_PER_PMD; pmd++, i++, address += PMD_SIZE) {
 		unsigned long entry;
 
 		if (address >= end) {

@@ -263,6 +265,11 @@
 					set_pmd(pmd, __pmd(0));
 			break;
 		}
+		
+		if (pmd_val(*pmd)) {
+			printk (KERN_ERR "%s trying to trample pte entry \
+				%08lx@%08lx\n",__func__,pmd_val(*pmd),address);
+		}
 		entry = _PAGE_NX|_PAGE_PSE|_KERNPG_TABLE|_PAGE_GLOBAL|address;
 		entry &= __supported_pte_mask;
 		set_pmd(pmd, __pmd(entry));

@@ -272,45 +279,42 @@
 static void __meminit
 phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end)
 {
-	pmd_t *pmd = pmd_offset(pud, (unsigned long)__va(address));
-
-	if (pmd_none(*pmd)) {
-		spin_lock(&init_mm.page_table_lock);
-		phys_pmd_init(pmd, address, end);
-		spin_unlock(&init_mm.page_table_lock);
-		__flush_tlb_all();
-	}
+	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, unsigned long address, unsigned long end)
 { 
-	long i = pud_index(address);
+	int i = pud_index(address);
 
 	pud = pud + i;
 
-	if (after_bootmem && pud_val(*pud)) {
-		phys_pmd_update(pud, address, end);
-		return;
-	}
-
-	for (; i < PTRS_PER_PUD; pud++, i++) {
+	for (; i < PTRS_PER_PUD; pud++, i++, \
+			address = (address & PUD_MASK) + PUD_SIZE ) {
 		int map; 
-		unsigned long paddr, pmd_phys;
+		unsigned long pmd_phys;
 		pmd_t *pmd;
 
-		paddr = (address & PGDIR_MASK) + i*PUD_SIZE;
-		if (paddr >= end)
+		if (address >= end)
 			break;
 
-		if (!after_bootmem && !e820_any_mapped(paddr, paddr+PUD_SIZE, 0)) {
+		if (!after_bootmem && !e820_any_mapped(address, address+PUD_SIZE, 0)) {
 			set_pud(pud, __pud(0)); 
 			continue;
 		} 
 
+		if (pud_val(*pud)) {
+			phys_pmd_update(pud, address, end);
+			continue;
+		}
+
 		pmd = alloc_low_page(&map, &pmd_phys);
 		spin_lock(&init_mm.page_table_lock);
 		set_pud(pud, __pud(pmd_phys | _KERNPG_TABLE));
-		phys_pmd_init(pmd, paddr, end);
+		phys_pmd_init(pmd, address, end);
 		spin_unlock(&init_mm.page_table_lock);
 		unmap_low_page(map);
 	}