1 files changed, 393 insertions, 0 deletions
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
new file mode 100644
index 0000000..fd3da1d
--- /dev/null
+++ b/arch/x86/mm/init.c
@@ -0,0 +1,393 @@
+#include <linux/ioport.h>
+#include <linux/swap.h>
+
+#include <asm/cacheflush.h>
+#include <asm/e820.h>
+#include <asm/init.h>
+#include <asm/page.h>
+#include <asm/page_types.h>
+#include <asm/sections.h>
+#include <asm/system.h>
+#include <asm/tlbflush.h>
+
+unsigned long __initdata e820_table_start;
+unsigned long __meminitdata e820_table_end;
+unsigned long __meminitdata e820_table_top;
+
+int after_bootmem;
+
+int direct_gbpages
+#ifdef CONFIG_DIRECT_GBPAGES
+				= 1
+#endif
+;
+
+static void __init find_early_table_space(unsigned long end, int use_pse,
+					  int use_gbpages)
+{
+	unsigned long puds, pmds, ptes, tables, start;
+
+	puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
+	tables = roundup(puds * sizeof(pud_t), PAGE_SIZE);
+
+	if (use_gbpages) {
+		unsigned long extra;
+
+		extra = end - ((end>>PUD_SHIFT) << PUD_SHIFT);
+		pmds = (extra + PMD_SIZE - 1) >> PMD_SHIFT;
+	} else
+		pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
+
+	tables += roundup(pmds * sizeof(pmd_t), PAGE_SIZE);
+
+	if (use_pse) {
+		unsigned long extra;
+
+		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;
+
+	tables += roundup(ptes * sizeof(pte_t), PAGE_SIZE);
+
+#ifdef CONFIG_X86_32
+	/* for fixmap */
+	tables += roundup(__end_of_fixed_addresses * sizeof(pte_t), PAGE_SIZE);
+#endif
+
+	/*
+	 * 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;
+	e820_table_start = find_e820_area(start, max_pfn_mapped<<PAGE_SHIFT,
+					tables, PAGE_SIZE);
+#else /* CONFIG_X86_64 */
+	start = 0x8000;
+	e820_table_start = find_e820_area(start, end, tables, PAGE_SIZE);
+#endif
+	if (e820_table_start == -1UL)
+		panic("Cannot find space for the kernel page tables");
+
+	e820_table_start >>= PAGE_SHIFT;
+	e820_table_end = e820_table_start;
+	e820_table_top = e820_table_start + (tables >> PAGE_SHIFT);
+
+	printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n",
+		end, e820_table_start << PAGE_SHIFT, e820_table_top << PAGE_SHIFT);
+}
+
+struct map_range {
+	unsigned long start;
+	unsigned long end;
+	unsigned page_size_mask;
+};
+
+#ifdef CONFIG_X86_32
+#define NR_RANGE_MR 3
+#else /* CONFIG_X86_64 */
+#define NR_RANGE_MR 5
+#endif
+
+static int __meminit save_mr(struct map_range *mr, int nr_range,
+			     unsigned long start_pfn, unsigned long end_pfn,
+			     unsigned long page_size_mask)
+{
+	if (start_pfn < end_pfn) {
+		if (nr_range >= NR_RANGE_MR)
+			panic("run out of range for init_memory_mapping\n");
+		mr[nr_range].start = start_pfn<<PAGE_SHIFT;
+		mr[nr_range].end   = end_pfn<<PAGE_SHIFT;
+		mr[nr_range].page_size_mask = page_size_mask;
+		nr_range++;
+	}
+
+	return nr_range;
+}
+
+#ifdef CONFIG_X86_64
+static void __init init_gbpages(void)
+{
+	if (direct_gbpages && cpu_has_gbpages)
+		printk(KERN_INFO "Using GB pages for direct mapping\n");
+	else
+		direct_gbpages = 0;
+}
+#else
+static inline void init_gbpages(void)
+{
+}
+#endif
+
+/*
+ * 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)
+{
+	unsigned long page_size_mask = 0;
+	unsigned long start_pfn, end_pfn;
+	unsigned long ret = 0;
+	unsigned long pos;
+
+	struct map_range mr[NR_RANGE_MR];
+	int nr_range, i;
+	int use_pse, use_gbpages;
+
+	printk(KERN_INFO "init_memory_mapping: %016lx-%016lx\n", start, end);
+
+	if (!after_bootmem)
+		init_gbpages();
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+	/*
+	 * 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;
+#endif
+
+#ifdef CONFIG_X86_32
+#ifdef CONFIG_X86_PAE
+	set_nx();
+	if (nx_enabled)
+		printk(KERN_INFO "NX (Execute Disable) protection: active\n");
+#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;
+	}
+#endif
+
+	if (use_gbpages)
+		page_size_mask |= 1 << PG_LEVEL_1G;
+	if (use_pse)
+		page_size_mask |= 1 << PG_LEVEL_2M;
+
+	memset(mr, 0, sizeof(mr));
+	nr_range = 0;
+
+	/* head if not big page alignment ? */
+	start_pfn = start >> PAGE_SHIFT;
+	pos = start_pfn << PAGE_SHIFT;
+#ifdef CONFIG_X86_32
+	/*
+	 * Don't use a large page for the first 2/4MB of memory
+	 * because there are often fixed size MTRRs in there
+	 * and overlapping MTRRs into large pages can cause
+	 * slowdowns.
+	 */
+	if (pos == 0)
+		end_pfn = 1<<(PMD_SHIFT - PAGE_SHIFT);
+	else
+		end_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
+				 << (PMD_SHIFT - PAGE_SHIFT);
+#else /* CONFIG_X86_64 */
+	end_pfn = ((pos + (PMD_SIZE - 1)) >> PMD_SHIFT)
+			<< (PMD_SHIFT - PAGE_SHIFT);
+#endif
+	if (end_pfn > (end >> PAGE_SHIFT))
+		end_pfn = end >> PAGE_SHIFT;
+	if (start_pfn < end_pfn) {
+		nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
+		pos = end_pfn << PAGE_SHIFT;
+	}
+
+	/* big page (2M) range */
+	start_pfn = ((pos + (PMD_SIZE - 1))>>PMD_SHIFT)
+			 << (PMD_SHIFT - PAGE_SHIFT);
+#ifdef CONFIG_X86_32
+	end_pfn = (end>>PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT);
+#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));
+#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;
+	}
+
+#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);
+	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;
+	}
+
+	/* 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);
+	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;
+	}
+#endif
+
+	/* tail is not big page (2M) alignment */
+	start_pfn = pos>>PAGE_SHIFT;
+	end_pfn = end>>PAGE_SHIFT;
+	nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0);
+
+	/* try to merge same page size and continuous */
+	for (i = 0; nr_range > 1 && i < nr_range - 1; i++) {
+		unsigned long old_start;
+		if (mr[i].end != mr[i+1].start ||
+		    mr[i].page_size_mask != mr[i+1].page_size_mask)
+			continue;
+		/* move it */
+		old_start = mr[i].start;
+		memmove(&mr[i], &mr[i+1],
+			(nr_range - 1 - i) * sizeof(struct map_range));
+		mr[i--].start = old_start;
+		nr_range--;
+	}
+
+	for (i = 0; i < nr_range; i++)
+		printk(KERN_DEBUG " %010lx - %010lx page %s\n",
+				mr[i].start, mr[i].end,
+			(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);
+
+#ifdef CONFIG_X86_32
+	for (i = 0; i < nr_range; i++)
+		kernel_physical_mapping_init(mr[i].start, mr[i].end,
+					     mr[i].page_size_mask);
+	ret = end;
+#else /* CONFIG_X86_64 */
+	for (i = 0; i < nr_range; i++)
+		ret = kernel_physical_mapping_init(mr[i].start, mr[i].end,
+						   mr[i].page_size_mask);
+#endif
+
+#ifdef CONFIG_X86_32
+	early_ioremap_page_table_range_init();
+
+	load_cr3(swapper_pg_dir);
+#endif
+
+#ifdef CONFIG_X86_64
+	if (!after_bootmem)
+		mmu_cr4_features = read_cr4();
+#endif
+	__flush_tlb_all();
+
+	if (!after_bootmem && e820_table_end > e820_table_start)
+		reserve_early(e820_table_start << PAGE_SHIFT,
+				 e820_table_end << PAGE_SHIFT, "PGTABLE");
+
+	if (!after_bootmem)
+		early_memtest(start, end);
+
+	return ret >> PAGE_SHIFT;
+}
+
+
+/*
+ * devmem_is_allowed() checks to see if /dev/mem access to a certain address
+ * is valid. The argument is a physical page number.
+ *
+ *
+ * On x86, access has to be given to the first megabyte of ram because that area
+ * contains bios code and data regions used by X and dosemu and similar apps.
+ * Access has to be given to non-kernel-ram areas as well, these contain the PCI
+ * mmio resources as well as potential bios/acpi data regions.
+ */
+int devmem_is_allowed(unsigned long pagenr)
+{
+	if (pagenr <= 256)
+		return 1;
+	if (iomem_is_exclusive(pagenr << PAGE_SHIFT))
+		return 0;
+	if (!page_is_ram(pagenr))
+		return 1;
+	return 0;
+}
+
+void free_init_pages(char *what, unsigned long begin, unsigned long end)
+{
+	unsigned long addr = begin;
+
+	if (addr >= end)
+		return;
+
+	/*
+	 * 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, PAGE_ALIGN(end));
+	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.
+	 */
+	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 & ~(PAGE_SIZE-1)),
+			POISON_FREE_INITMEM, PAGE_SIZE);
+		free_page(addr);
+		totalram_pages++;
+	}
+#endif
+}
+
+void free_initmem(void)
+{
+	free_init_pages("unused kernel memory",
+			(unsigned long)(&__init_begin),
+			(unsigned long)(&__init_end));
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void free_initrd_mem(unsigned long start, unsigned long end)
+{
+	free_init_pages("initrd memory", start, end);
+}
+#endif