1 files changed, 457 insertions, 179 deletions

diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index c0e28a13de7..f9713061811 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -3,6 +3,7 @@
 #include <linux/ioport.h>
 #include <linux/swap.h>
 #include <linux/memblock.h>
+#include <linux/bootmem.h>	/* for max_low_pfn */
 
 #include <asm/cacheflush.h>
 #include <asm/e820.h>
@@ -11,83 +12,103 @@
 #include <asm/page_types.h>
 #include <asm/sections.h>
 #include <asm/setup.h>
-#include <asm/system.h>
 #include <asm/tlbflush.h>
 #include <asm/tlb.h>
 #include <asm/proto.h>
+#include <asm/dma.h>		/* for MAX_DMA_PFN */
+#include <asm/microcode.h>
 
-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
+#include "mm_internal.h"
 
-unsigned long __initdata e820_table_start;
-unsigned long __meminitdata e820_table_end;
-unsigned long __meminitdata e820_table_top;
+static unsigned long __initdata pgt_buf_start;
+static unsigned long __initdata pgt_buf_end;
+static unsigned long __initdata pgt_buf_top;
 
-int after_bootmem;
+static unsigned long min_pfn_mapped;
 
-int direct_gbpages
-#ifdef CONFIG_DIRECT_GBPAGES
-				= 1
-#endif
-;
+static bool __initdata can_use_brk_pgt = true;
 
-static void __init find_early_table_space(unsigned long end, int use_pse,
-					  int use_gbpages)
+/*
+ * Pages returned are already directly mapped.
+ *
+ * Changing that is likely to break Xen, see commit:
+ *
+ *    279b706 x86,xen: introduce x86_init.mapping.pagetable_reserve
+ *
+ * for detailed information.
+ */
+__ref void *alloc_low_pages(unsigned int num)
 {
-	unsigned long puds, pmds, ptes, tables, start;
-	phys_addr_t base;
+	unsigned long pfn;
+	int i;
 
-	puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
-	tables = roundup(puds * sizeof(pud_t), PAGE_SIZE);
+	if (after_bootmem) {
+		unsigned int order;
 
-	if (use_gbpages) {
-		unsigned long extra;
+		order = get_order((unsigned long)num << PAGE_SHIFT);
+		return (void *)__get_free_pages(GFP_ATOMIC | __GFP_NOTRACK |
+						__GFP_ZERO, order);
+	}
 
-		extra = end - ((end>>PUD_SHIFT) << PUD_SHIFT);
-		pmds = (extra + PMD_SIZE - 1) >> PMD_SHIFT;
-	} else
-		pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
+	if ((pgt_buf_end + num) > pgt_buf_top || !can_use_brk_pgt) {
+		unsigned long ret;
+		if (min_pfn_mapped >= max_pfn_mapped)
+			panic("alloc_low_pages: ran out of memory");
+		ret = memblock_find_in_range(min_pfn_mapped << PAGE_SHIFT,
+					max_pfn_mapped << PAGE_SHIFT,
+					PAGE_SIZE * num , PAGE_SIZE);
+		if (!ret)
+			panic("alloc_low_pages: can not alloc memory");
+		memblock_reserve(ret, PAGE_SIZE * num);
+		pfn = ret >> PAGE_SHIFT;
+	} else {
+		pfn = pgt_buf_end;
+		pgt_buf_end += num;
+		printk(KERN_DEBUG "BRK [%#010lx, %#010lx] PGTABLE\n",
+			pfn << PAGE_SHIFT, (pgt_buf_end << PAGE_SHIFT) - 1);
+	}
 
-	tables += roundup(pmds * sizeof(pmd_t), PAGE_SIZE);
+	for (i = 0; i < num; i++) {
+		void *adr;
 
-	if (use_pse) {
-		unsigned long extra;
+		adr = __va((pfn + i) << PAGE_SHIFT);
+		clear_page(adr);
+	}
 
-		extra = end - ((end>>PMD_SHIFT) << PMD_SHIFT);
-#ifdef CONFIG_X86_32
-		extra += PMD_SIZE;
-#endif
-		ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT;
-	} else
-		ptes = (end + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	return __va(pfn << PAGE_SHIFT);
+}
 
-	tables += roundup(ptes * sizeof(pte_t), PAGE_SIZE);
+/* need 3 4k for initial PMD_SIZE,  3 4k for 0-ISA_END_ADDRESS */
+#define INIT_PGT_BUF_SIZE	(6 * PAGE_SIZE)
+RESERVE_BRK(early_pgt_alloc, INIT_PGT_BUF_SIZE);
+void  __init early_alloc_pgt_buf(void)
+{
+	unsigned long tables = INIT_PGT_BUF_SIZE;
+	phys_addr_t base;
 
-#ifdef CONFIG_X86_32
-	/* for fixmap */
-	tables += roundup(__end_of_fixed_addresses * sizeof(pte_t), PAGE_SIZE);
-#endif
+	base = __pa(extend_brk(tables, 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.
-	 */
-#ifdef CONFIG_X86_32
-	start = 0x7000;
-#else
-	start = 0x8000;
-#endif
-	base = memblock_find_in_range(start, max_pfn_mapped<<PAGE_SHIFT,
-					tables, PAGE_SIZE);
-	if (base == MEMBLOCK_ERROR)
-		panic("Cannot find space for the kernel page tables");
+	pgt_buf_start = base >> PAGE_SHIFT;
+	pgt_buf_end = pgt_buf_start;
+	pgt_buf_top = pgt_buf_start + (tables >> PAGE_SHIFT);
+}
+
+int after_bootmem;
 
-	e820_table_start = base >> PAGE_SHIFT;
-	e820_table_end = e820_table_start;
-	e820_table_top = e820_table_start + (tables >> PAGE_SHIFT);
+int direct_gbpages
+#ifdef CONFIG_DIRECT_GBPAGES
+				= 1
+#endif
+;
 
-	printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n",
-		end, e820_table_start << PAGE_SHIFT, e820_table_top << PAGE_SHIFT);
+static void __init init_gbpages(void)
+{
+#ifdef CONFIG_X86_64
+	if (direct_gbpages && cpu_has_gbpages)
+		printk(KERN_INFO "Using GB pages for direct mapping\n");
+	else
+		direct_gbpages = 0;
+#endif
 }
 
 struct map_range {
@@ -96,6 +117,35 @@ struct map_range {
 	unsigned page_size_mask;
 };
 
+static int page_size_mask;
+
+static void __init probe_page_size_mask(void)
+{
+	init_gbpages();
+
+#if !defined(CONFIG_DEBUG_PAGEALLOC) && !defined(CONFIG_KMEMCHECK)
+	/*
+	 * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
+	 * This will simplify cpa(), which otherwise needs to support splitting
+	 * large pages into small in interrupt context, etc.
+	 */
+	if (direct_gbpages)
+		page_size_mask |= 1 << PG_LEVEL_1G;
+	if (cpu_has_pse)
+		page_size_mask |= 1 << PG_LEVEL_2M;
+#endif
+
+	/* Enable PSE if available */
+	if (cpu_has_pse)
+		set_in_cr4(X86_CR4_PSE);
+
+	/* Enable PGE if available */
+	if (cpu_has_pge) {
+		set_in_cr4(X86_CR4_PGE);
+		__supported_pte_mask |= _PAGE_GLOBAL;
+	}
+}
+
 #ifdef CONFIG_X86_32
 #define NR_RANGE_MR 3
 #else /* CONFIG_X86_64 */
@@ -119,57 +169,51 @@ static int __meminit save_mr(struct map_range *mr, int nr_range,
 }
 
 /*
- * 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.
+ * adjust the page_size_mask for small range to go with
+ *	big page size instead small one if nearby are ram too.
  */
-unsigned long __init_refok init_memory_mapping(unsigned long start,
-					       unsigned long end)
+static void __init_refok adjust_range_page_size_mask(struct map_range *mr,
+							 int nr_range)
 {
-	unsigned long page_size_mask = 0;
-	unsigned long start_pfn, end_pfn;
-	unsigned long ret = 0;
-	unsigned long pos;
+	int i;
 
-	struct map_range mr[NR_RANGE_MR];
-	int nr_range, i;
-	int use_pse, use_gbpages;
+	for (i = 0; i < nr_range; i++) {
+		if ((page_size_mask & (1<<PG_LEVEL_2M)) &&
+		    !(mr[i].page_size_mask & (1<<PG_LEVEL_2M))) {
+			unsigned long start = round_down(mr[i].start, PMD_SIZE);
+			unsigned long end = round_up(mr[i].end, PMD_SIZE);
 
-	printk(KERN_INFO "init_memory_mapping: %016lx-%016lx\n", start, end);
-
-#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK)
-	/*
-	 * For CONFIG_DEBUG_PAGEALLOC, identity mapping will use small pages.
-	 * This will simplify cpa(), which otherwise needs to support splitting
-	 * large pages into small in interrupt context, etc.
-	 */
-	use_pse = use_gbpages = 0;
-#else
-	use_pse = cpu_has_pse;
-	use_gbpages = direct_gbpages;
+#ifdef CONFIG_X86_32
+			if ((end >> PAGE_SHIFT) > max_low_pfn)
+				continue;
 #endif
 
-	/* Enable PSE if available */
-	if (cpu_has_pse)
-		set_in_cr4(X86_CR4_PSE);
-
-	/* Enable PGE if available */
-	if (cpu_has_pge) {
-		set_in_cr4(X86_CR4_PGE);
-		__supported_pte_mask |= _PAGE_GLOBAL;
+			if (memblock_is_region_memory(start, end - start))
+				mr[i].page_size_mask |= 1<<PG_LEVEL_2M;
+		}
+		if ((page_size_mask & (1<<PG_LEVEL_1G)) &&
+		    !(mr[i].page_size_mask & (1<<PG_LEVEL_1G))) {
+			unsigned long start = round_down(mr[i].start, PUD_SIZE);
+			unsigned long end = round_up(mr[i].end, PUD_SIZE);
+
+			if (memblock_is_region_memory(start, end - start))
+				mr[i].page_size_mask |= 1<<PG_LEVEL_1G;
+		}
 	}
+}
 
-	if (use_gbpages)
-		page_size_mask |= 1 << PG_LEVEL_1G;
-	if (use_pse)
-		page_size_mask |= 1 << PG_LEVEL_2M;
+static int __meminit split_mem_range(struct map_range *mr, int nr_range,
+				     unsigned long start,
+				     unsigned long end)
+{
+	unsigned long start_pfn, end_pfn, limit_pfn;
+	unsigned long pfn;
+	int i;
 
-	memset(mr, 0, sizeof(mr));
-	nr_range = 0;
+	limit_pfn = PFN_DOWN(end);
 
 	/* head if not big page alignment ? */
-	start_pfn = start >> PAGE_SHIFT;
-	pos = start_pfn << PAGE_SHIFT;
+	pfn = start_pfn = PFN_DOWN(start);
 #ifdef CONFIG_X86_32
 	/*
 	 * Don't use a large page for the first 2/4MB of memory
@@ -177,68 +221,65 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
 	 * and overlapping MTRRs into large pages can cause
 	 * slowdowns.
 	 */
-	if (pos == 0)
-		end_pfn = 1<<(PMD_SHIFT - PAGE_SHIFT);
+	if (pfn == 0)
+		end_pfn = PFN_DOWN(PMD_SIZE);
 	else
-		end_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
-				 << (PMD_SHIFT - PAGE_SHIFT);
+		end_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
 #else /* CONFIG_X86_64 */
-	end_pfn = ((pos + (PMD_SIZE - 1)) >> PMD_SHIFT)
-			<< (PMD_SHIFT - PAGE_SHIFT);
+	end_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
 #endif
-	if (end_pfn > (end >> PAGE_SHIFT))
-		end_pfn = end >> PAGE_SHIFT;
+	if (end_pfn > limit_pfn)
+		end_pfn = limit_pfn;
 	if (start_pfn < end_pfn) {
 		nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
-		pos = end_pfn << PAGE_SHIFT;
+		pfn = end_pfn;
 	}
 
 	/* big page (2M) range */
-	start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
-			 << (PMD_SHIFT - PAGE_SHIFT);
+	start_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
 #ifdef CONFIG_X86_32
-	end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
+	end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE));
 #else /* CONFIG_X86_64 */
-	end_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT)
-			 << (PUD_SHIFT - PAGE_SHIFT);
-	if (end_pfn > ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT)))
-		end_pfn = ((end>>PMD_SHIFT)<<(PMD_SHIFT - PAGE_SHIFT));
+	end_pfn = round_up(pfn, PFN_DOWN(PUD_SIZE));
+	if (end_pfn > round_down(limit_pfn, PFN_DOWN(PMD_SIZE)))
+		end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE));
 #endif
 
 	if (start_pfn < end_pfn) {
 		nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
 				page_size_mask & (1<<PG_LEVEL_2M));
-		pos = end_pfn << PAGE_SHIFT;
+		pfn = end_pfn;
 	}
 
 #ifdef CONFIG_X86_64
 	/* big page (1G) range */
-	start_pfn = ((pos + (PUD_SIZE - 1))>>PUD_SHIFT)
-			 << (PUD_SHIFT - PAGE_SHIFT);
-	end_pfn = (end >> PUD_SHIFT) << (PUD_SHIFT - PAGE_SHIFT);
+	start_pfn = round_up(pfn, PFN_DOWN(PUD_SIZE));
+	end_pfn = round_down(limit_pfn, PFN_DOWN(PUD_SIZE));
 	if (start_pfn < end_pfn) {
 		nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
 				page_size_mask &
 				 ((1<<PG_LEVEL_2M)|(1<<PG_LEVEL_1G)));
-		pos = end_pfn << PAGE_SHIFT;
+		pfn = end_pfn;
 	}
 
 	/* tail is not big page (1G) alignment */
-	start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
-			 << (PMD_SHIFT - PAGE_SHIFT);
-	end_pfn = (end >> PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
+	start_pfn = round_up(pfn, PFN_DOWN(PMD_SIZE));
+	end_pfn = round_down(limit_pfn, PFN_DOWN(PMD_SIZE));
 	if (start_pfn < end_pfn) {
 		nr_range = save_mr(mr, nr_range, start_pfn, end_pfn,
 				page_size_mask & (1<<PG_LEVEL_2M));
-		pos = end_pfn << PAGE_SHIFT;
+		pfn = end_pfn;
 	}
 #endif
 
 	/* tail is not big page (2M) alignment */
-	start_pfn = pos>>PAGE_SHIFT;
-	end_pfn = end>>PAGE_SHIFT;
+	start_pfn = pfn;
+	end_pfn = limit_pfn;
 	nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
 
+	if (!after_bootmem)
+		adjust_range_page_size_mask(mr, nr_range);
+
 	/* try to merge same page size and continuous */
 	for (i = 0; nr_range > 1 && i < nr_range - 1; i++) {
 		unsigned long old_start;
@@ -254,62 +295,279 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
 	}
 
 	for (i = 0; i < nr_range; i++)
-		printk(KERN_DEBUG " %010lx - %010lx page %s\n",
-				mr[i].start, mr[i].end,
+		printk(KERN_DEBUG " [mem %#010lx-%#010lx] page %s\n",
+				mr[i].start, mr[i].end - 1,
 			(mr[i].page_size_mask & (1<<PG_LEVEL_1G))?"1G":(
 			 (mr[i].page_size_mask & (1<<PG_LEVEL_2M))?"2M":"4k"));
 
-	/*
-	 * 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, use_pse, use_gbpages);
+	return nr_range;
+}
+
+struct range pfn_mapped[E820_X_MAX];
+int nr_pfn_mapped;
+
+static void add_pfn_range_mapped(unsigned long start_pfn, unsigned long end_pfn)
+{
+	nr_pfn_mapped = add_range_with_merge(pfn_mapped, E820_X_MAX,
+					     nr_pfn_mapped, start_pfn, end_pfn);
+	nr_pfn_mapped = clean_sort_range(pfn_mapped, E820_X_MAX);
+
+	max_pfn_mapped = max(max_pfn_mapped, end_pfn);
+
+	if (start_pfn < (1UL<<(32-PAGE_SHIFT)))
+		max_low_pfn_mapped = max(max_low_pfn_mapped,
+					 min(end_pfn, 1UL<<(32-PAGE_SHIFT)));
+}
+
+bool pfn_range_is_mapped(unsigned long start_pfn, unsigned long end_pfn)
+{
+	int i;
+
+	for (i = 0; i < nr_pfn_mapped; i++)
+		if ((start_pfn >= pfn_mapped[i].start) &&
+		    (end_pfn <= pfn_mapped[i].end))
+			return true;
+
+	return false;
+}
+
+/*
+ * 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.
+ */
+unsigned long __init_refok init_memory_mapping(unsigned long start,
+					       unsigned long end)
+{
+	struct map_range mr[NR_RANGE_MR];
+	unsigned long ret = 0;
+	int nr_range, i;
+
+	pr_info("init_memory_mapping: [mem %#010lx-%#010lx]\n",
+	       start, end - 1);
+
+	memset(mr, 0, sizeof(mr));
+	nr_range = split_mem_range(mr, 0, start, end);
 
 	for (i = 0; i < nr_range; i++)
 		ret = kernel_physical_mapping_init(mr[i].start, mr[i].end,
 						   mr[i].page_size_mask);
 
-#ifdef CONFIG_X86_32
-	early_ioremap_page_table_range_init();
+	add_pfn_range_mapped(start >> PAGE_SHIFT, ret >> PAGE_SHIFT);
 
-	load_cr3(swapper_pg_dir);
-#endif
+	return ret >> PAGE_SHIFT;
+}
 
-#ifdef CONFIG_X86_64
-	if (!after_bootmem && !start) {
-		pud_t *pud;
-		pmd_t *pmd;
+/*
+ * We need to iterate through the E820 memory map and create direct mappings
+ * for only E820_RAM and E820_KERN_RESERVED regions. We cannot simply
+ * create direct mappings for all pfns from [0 to max_low_pfn) and
+ * [4GB to max_pfn) because of possible memory holes in high addresses
+ * that cannot be marked as UC by fixed/variable range MTRRs.
+ * Depending on the alignment of E820 ranges, this may possibly result
+ * in using smaller size (i.e. 4K instead of 2M or 1G) page tables.
+ *
+ * init_mem_mapping() calls init_range_memory_mapping() with big range.
+ * That range would have hole in the middle or ends, and only ram parts
+ * will be mapped in init_range_memory_mapping().
+ */
+static unsigned long __init init_range_memory_mapping(
+					   unsigned long r_start,
+					   unsigned long r_end)
+{
+	unsigned long start_pfn, end_pfn;
+	unsigned long mapped_ram_size = 0;
+	int i;
 
-		mmu_cr4_features = read_cr4();
+	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL) {
+		u64 start = clamp_val(PFN_PHYS(start_pfn), r_start, r_end);
+		u64 end = clamp_val(PFN_PHYS(end_pfn), r_start, r_end);
+		if (start >= end)
+			continue;
 
 		/*
-		 * _brk_end cannot change anymore, but it and _end may be
-		 * located on different 2M pages. cleanup_highmap(), however,
-		 * can only consider _end when it runs, so destroy any
-		 * mappings beyond _brk_end here.
+		 * if it is overlapping with brk pgt, we need to
+		 * alloc pgt buf from memblock instead.
 		 */
-		pud = pud_offset(pgd_offset_k(_brk_end), _brk_end);
-		pmd = pmd_offset(pud, _brk_end - 1);
-		while (++pmd <= pmd_offset(pud, (unsigned long)_end - 1))
-			pmd_clear(pmd);
+		can_use_brk_pgt = max(start, (u64)pgt_buf_end<<PAGE_SHIFT) >=
+				    min(end, (u64)pgt_buf_top<<PAGE_SHIFT);
+		init_memory_mapping(start, end);
+		mapped_ram_size += end - start;
+		can_use_brk_pgt = true;
 	}
-#endif
-	__flush_tlb_all();
 
-	if (!after_bootmem && e820_table_end > e820_table_start)
-		memblock_x86_reserve_range(e820_table_start << PAGE_SHIFT,
-				 e820_table_end << PAGE_SHIFT, "PGTABLE");
+	return mapped_ram_size;
+}
 
-	if (!after_bootmem)
-		early_memtest(start, end);
+static unsigned long __init get_new_step_size(unsigned long step_size)
+{
+	/*
+	 * Explain why we shift by 5 and why we don't have to worry about
+	 * 'step_size << 5' overflowing:
+	 *
+	 * initial mapped size is PMD_SIZE (2M).
+	 * We can not set step_size to be PUD_SIZE (1G) yet.
+	 * In worse case, when we cross the 1G boundary, and
+	 * PG_LEVEL_2M is not set, we will need 1+1+512 pages (2M + 8k)
+	 * to map 1G range with PTE. Use 5 as shift for now.
+	 *
+	 * Don't need to worry about overflow, on 32bit, when step_size
+	 * is 0, round_down() returns 0 for start, and that turns it
+	 * into 0x100000000ULL.
+	 */
+	return step_size << 5;
+}
 
-	return ret >> PAGE_SHIFT;
+/**
+ * memory_map_top_down - Map [map_start, map_end) top down
+ * @map_start: start address of the target memory range
+ * @map_end: end address of the target memory range
+ *
+ * This function will setup direct mapping for memory range
+ * [map_start, map_end) in top-down. That said, the page tables
+ * will be allocated at the end of the memory, and we map the
+ * memory in top-down.
+ */
+static void __init memory_map_top_down(unsigned long map_start,
+				       unsigned long map_end)
+{
+	unsigned long real_end, start, last_start;
+	unsigned long step_size;
+	unsigned long addr;
+	unsigned long mapped_ram_size = 0;
+	unsigned long new_mapped_ram_size;
+
+	/* xen has big range in reserved near end of ram, skip it at first.*/
+	addr = memblock_find_in_range(map_start, map_end, PMD_SIZE, PMD_SIZE);
+	real_end = addr + PMD_SIZE;
+
+	/* step_size need to be small so pgt_buf from BRK could cover it */
+	step_size = PMD_SIZE;
+	max_pfn_mapped = 0; /* will get exact value next */
+	min_pfn_mapped = real_end >> PAGE_SHIFT;
+	last_start = start = real_end;
+
+	/*
+	 * We start from the top (end of memory) and go to the bottom.
+	 * The memblock_find_in_range() gets us a block of RAM from the
+	 * end of RAM in [min_pfn_mapped, max_pfn_mapped) used as new pages
+	 * for page table.
+	 */
+	while (last_start > map_start) {
+		if (last_start > step_size) {
+			start = round_down(last_start - 1, step_size);
+			if (start < map_start)
+				start = map_start;
+		} else
+			start = map_start;
+		new_mapped_ram_size = init_range_memory_mapping(start,
+							last_start);
+		last_start = start;
+		min_pfn_mapped = last_start >> PAGE_SHIFT;
+		/* only increase step_size after big range get mapped */
+		if (new_mapped_ram_size > mapped_ram_size)
+			step_size = get_new_step_size(step_size);
+		mapped_ram_size += new_mapped_ram_size;
+	}
+
+	if (real_end < map_end)
+		init_range_memory_mapping(real_end, map_end);
 }
 
+/**
+ * memory_map_bottom_up - Map [map_start, map_end) bottom up
+ * @map_start: start address of the target memory range
+ * @map_end: end address of the target memory range
+ *
+ * This function will setup direct mapping for memory range
+ * [map_start, map_end) in bottom-up. Since we have limited the
+ * bottom-up allocation above the kernel, the page tables will
+ * be allocated just above the kernel and we map the memory
+ * in [map_start, map_end) in bottom-up.
+ */
+static void __init memory_map_bottom_up(unsigned long map_start,
+					unsigned long map_end)
+{
+	unsigned long next, new_mapped_ram_size, start;
+	unsigned long mapped_ram_size = 0;
+	/* step_size need to be small so pgt_buf from BRK could cover it */
+	unsigned long step_size = PMD_SIZE;
+
+	start = map_start;
+	min_pfn_mapped = start >> PAGE_SHIFT;
+
+	/*
+	 * We start from the bottom (@map_start) and go to the top (@map_end).
+	 * The memblock_find_in_range() gets us a block of RAM from the
+	 * end of RAM in [min_pfn_mapped, max_pfn_mapped) used as new pages
+	 * for page table.
+	 */
+	while (start < map_end) {
+		if (map_end - start > step_size) {
+			next = round_up(start + 1, step_size);
+			if (next > map_end)
+				next = map_end;
+		} else
+			next = map_end;
+
+		new_mapped_ram_size = init_range_memory_mapping(start, next);
+		start = next;
+
+		if (new_mapped_ram_size > mapped_ram_size)
+			step_size = get_new_step_size(step_size);
+		mapped_ram_size += new_mapped_ram_size;
+	}
+}
+
+void __init init_mem_mapping(void)
+{
+	unsigned long end;
+
+	probe_page_size_mask();
+
+#ifdef CONFIG_X86_64
+	end = max_pfn << PAGE_SHIFT;
+#else
+	end = max_low_pfn << PAGE_SHIFT;
+#endif
+
+	/* the ISA range is always mapped regardless of memory holes */
+	init_memory_mapping(0, ISA_END_ADDRESS);
+
+	/*
+	 * If the allocation is in bottom-up direction, we setup direct mapping
+	 * in bottom-up, otherwise we setup direct mapping in top-down.
+	 */
+	if (memblock_bottom_up()) {
+		unsigned long kernel_end = __pa_symbol(_end);
+
+		/*
+		 * we need two separate calls here. This is because we want to
+		 * allocate page tables above the kernel. So we first map
+		 * [kernel_end, end) to make memory above the kernel be mapped
+		 * as soon as possible. And then use page tables allocated above
+		 * the kernel to map [ISA_END_ADDRESS, kernel_end).
+		 */
+		memory_map_bottom_up(kernel_end, end);
+		memory_map_bottom_up(ISA_END_ADDRESS, kernel_end);
+	} else {
+		memory_map_top_down(ISA_END_ADDRESS, end);
+	}
+
+#ifdef CONFIG_X86_64
+	if (max_pfn > max_low_pfn) {
+		/* can we preseve max_low_pfn ?*/
+		max_low_pfn = max_pfn;
+	}
+#else
+	early_ioremap_page_table_range_init();
+#endif
+
+	load_cr3(swapper_pg_dir);
+	__flush_tlb_all();
+
+	early_memtest(0, max_pfn_mapped << PAGE_SHIFT);
+}
 
 /*
  * devmem_is_allowed() checks to see if /dev/mem access to a certain address
@@ -323,7 +581,7 @@ unsigned long __init_refok init_memory_mapping(unsigned long start,
  */
 int devmem_is_allowed(unsigned long pagenr)
 {
-	if (pagenr <= 256)
+	if (pagenr < 256)
 		return 1;
 	if (iomem_is_exclusive(pagenr << PAGE_SHIFT))
 		return 0;
@@ -334,7 +592,6 @@ int devmem_is_allowed(unsigned long pagenr)
 
 void free_init_pages(char *what, unsigned long begin, unsigned long end)
 {
-	unsigned long addr;
 	unsigned long begin_aligned, end_aligned;
 
 	/* Make sure boundaries are page aligned */
@@ -349,47 +606,47 @@ void free_init_pages(char *what, unsigned long begin, unsigned long end)
 	if (begin >= end)
 		return;
 
-	addr = begin;
-
 	/*
 	 * If debugging page accesses then do not free this memory but
 	 * mark them not present - any buggy init-section access will
 	 * create a kernel page fault:
 	 */
 #ifdef CONFIG_DEBUG_PAGEALLOC
-	printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
-		begin, end);
+	printk(KERN_INFO "debug: unmapping init [mem %#010lx-%#010lx]\n",
+		begin, end - 1);
 	set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
 #else
 	/*
 	 * We just marked the kernel text read only above, now that
 	 * we are going to free part of that, we need to make that
-	 * writeable first.
+	 * writeable and non-executable first.
 	 */
+	set_memory_nx(begin, (end - begin) >> PAGE_SHIFT);
 	set_memory_rw(begin, (end - begin) >> PAGE_SHIFT);
 
-	printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
-
-	for (; addr < end; addr += PAGE_SIZE) {
-		ClearPageReserved(virt_to_page(addr));
-		init_page_count(virt_to_page(addr));
-		memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
-		free_page(addr);
-		totalram_pages++;
-	}
+	free_reserved_area((void *)begin, (void *)end, POISON_FREE_INITMEM, what);
 #endif
 }
 
 void free_initmem(void)
 {
-	free_init_pages("unused kernel memory",
+	free_init_pages("unused kernel",
 			(unsigned long)(&__init_begin),
 			(unsigned long)(&__init_end));
 }
 
 #ifdef CONFIG_BLK_DEV_INITRD
-void free_initrd_mem(unsigned long start, unsigned long end)
+void __init free_initrd_mem(unsigned long start, unsigned long end)
 {
+#ifdef CONFIG_MICROCODE_EARLY
+	/*
+	 * Remember, initrd memory may contain microcode or other useful things.
+	 * Before we lose initrd mem, we need to find a place to hold them
+	 * now that normal virtual memory is enabled.
+	 */
+	save_microcode_in_initrd();
+#endif
+
 	/*
 	 * end could be not aligned, and We can not align that,
 	 * decompresser could be confused by aligned initrd_end
@@ -399,6 +656,27 @@ void free_initrd_mem(unsigned long start, unsigned long end)
 	 *   - relocate_initrd()
 	 * So here We can do PAGE_ALIGN() safely to get partial page to be freed
 	 */
-	free_init_pages("initrd memory", start, PAGE_ALIGN(end));
+	free_init_pages("initrd", start, PAGE_ALIGN(end));
 }
 #endif
+
+void __init zone_sizes_init(void)
+{
+	unsigned long max_zone_pfns[MAX_NR_ZONES];
+
+	memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
+
+#ifdef CONFIG_ZONE_DMA
+	max_zone_pfns[ZONE_DMA]		= MAX_DMA_PFN;
+#endif
+#ifdef CONFIG_ZONE_DMA32
+	max_zone_pfns[ZONE_DMA32]	= MAX_DMA32_PFN;
+#endif
+	max_zone_pfns[ZONE_NORMAL]	= max_low_pfn;
+#ifdef CONFIG_HIGHMEM
+	max_zone_pfns[ZONE_HIGHMEM]	= max_pfn;
+#endif
+
+	free_area_init_nodes(max_zone_pfns);
+}
+