Initial commit

mm/sparse.c

@@ -0,0 +1,428 @@
+/*
+ * sparse memory mappings.
+ */
+#include <linux/mm.h>
+#include <linux/mmzone.h>
+#include <linux/bootmem.h>
+#include <linux/highmem.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/vmalloc.h>
+#include <asm/dma.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+
+/*
+ * Permanent SPARSEMEM data:
+ *
+ * 1) mem_section	- memory sections, mem_map's for valid memory
+ */
+#ifdef CONFIG_SPARSEMEM_EXTREME
+struct mem_section *mem_section[NR_SECTION_ROOTS]
+	____cacheline_internodealigned_in_smp;
+#else
+struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]
+	____cacheline_internodealigned_in_smp;
+#endif
+EXPORT_SYMBOL(mem_section);
+
+#ifdef NODE_NOT_IN_PAGE_FLAGS
+/*
+ * If we did not store the node number in the page then we have to
+ * do a lookup in the section_to_node_table in order to find which
+ * node the page belongs to.
+ */
+#if MAX_NUMNODES <= 256
+static u8 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
+#else
+static u16 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
+#endif
+
+int page_to_nid(struct page *page)
+{
+	return section_to_node_table[page_to_section(page)];
+}
+EXPORT_SYMBOL(page_to_nid);
+
+static void set_section_nid(unsigned long section_nr, int nid)
+{
+	section_to_node_table[section_nr] = nid;
+}
+#else /* !NODE_NOT_IN_PAGE_FLAGS */
+static inline void set_section_nid(unsigned long section_nr, int nid)
+{
+}
+#endif
+
+#ifdef CONFIG_SPARSEMEM_EXTREME
+static struct mem_section noinline __init_refok *sparse_index_alloc(int nid)
+{
+	struct mem_section *section = NULL;
+	unsigned long array_size = SECTIONS_PER_ROOT *
+				   sizeof(struct mem_section);
+
+	if (slab_is_available())
+		section = kmalloc_node(array_size, GFP_KERNEL, nid);
+	else
+		section = alloc_bootmem_node(NODE_DATA(nid), array_size);
+
+	if (section)
+		memset(section, 0, array_size);
+
+	return section;
+}
+
+static int __meminit sparse_index_init(unsigned long section_nr, int nid)
+{
+	static DEFINE_SPINLOCK(index_init_lock);
+	unsigned long root = SECTION_NR_TO_ROOT(section_nr);
+	struct mem_section *section;
+	int ret = 0;
+
+	if (mem_section[root])
+		return -EEXIST;
+
+	section = sparse_index_alloc(nid);
+	if (!section)
+		return -ENOMEM;
+	/*
+	 * This lock keeps two different sections from
+	 * reallocating for the same index
+	 */
+	spin_lock(&index_init_lock);
+
+	if (mem_section[root]) {
+		ret = -EEXIST;
+		goto out;
+	}
+
+	mem_section[root] = section;
+out:
+	spin_unlock(&index_init_lock);
+	return ret;
+}
+#else /* !SPARSEMEM_EXTREME */
+static inline int sparse_index_init(unsigned long section_nr, int nid)
+{
+	return 0;
+}
+#endif
+
+/*
+ * Although written for the SPARSEMEM_EXTREME case, this happens
+ * to also work for the flat array case because
+ * NR_SECTION_ROOTS==NR_MEM_SECTIONS.
+ */
+int __section_nr(struct mem_section* ms)
+{
+	unsigned long root_nr;
+	struct mem_section* root;
+
+	for (root_nr = 0; root_nr < NR_SECTION_ROOTS; root_nr++) {
+		root = __nr_to_section(root_nr * SECTIONS_PER_ROOT);
+		if (!root)
+			continue;
+
+		if ((ms >= root) && (ms < (root + SECTIONS_PER_ROOT)))
+		     break;
+	}
+
+	return (root_nr * SECTIONS_PER_ROOT) + (ms - root);
+}
+
+/*
+ * During early boot, before section_mem_map is used for an actual
+ * mem_map, we use section_mem_map to store the section's NUMA
+ * node.  This keeps us from having to use another data structure.  The
+ * node information is cleared just before we store the real mem_map.
+ */
+static inline unsigned long sparse_encode_early_nid(int nid)
+{
+	return (nid << SECTION_NID_SHIFT);
+}
+
+static inline int sparse_early_nid(struct mem_section *section)
+{
+	return (section->section_mem_map >> SECTION_NID_SHIFT);
+}
+
+/* Record a memory area against a node. */
+void __init memory_present(int nid, unsigned long start, unsigned long end)
+{
+	unsigned long max_arch_pfn = 1UL << (MAX_PHYSMEM_BITS-PAGE_SHIFT);
+	unsigned long pfn;
+
+	/*
+	 * Sanity checks - do not allow an architecture to pass
+	 * in larger pfns than the maximum scope of sparsemem:
+	 */
+	if (start >= max_arch_pfn)
+		return;
+	if (end >= max_arch_pfn)
+		end = max_arch_pfn;
+
+	start &= PAGE_SECTION_MASK;
+	for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
+		unsigned long section = pfn_to_section_nr(pfn);
+		struct mem_section *ms;
+
+		sparse_index_init(section, nid);
+		set_section_nid(section, nid);
+
+		ms = __nr_to_section(section);
+		if (!ms->section_mem_map)
+			ms->section_mem_map = sparse_encode_early_nid(nid) |
+							SECTION_MARKED_PRESENT;
+	}
+}
+
+/*
+ * Only used by the i386 NUMA architecures, but relatively
+ * generic code.
+ */
+unsigned long __init node_memmap_size_bytes(int nid, unsigned long start_pfn,
+						     unsigned long end_pfn)
+{
+	unsigned long pfn;
+	unsigned long nr_pages = 0;
+
+	for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
+		if (nid != early_pfn_to_nid(pfn))
+			continue;
+
+		if (pfn_present(pfn))
+			nr_pages += PAGES_PER_SECTION;
+	}
+
+	return nr_pages * sizeof(struct page);
+}
+
+/*
+ * Subtle, we encode the real pfn into the mem_map such that
+ * the identity pfn - section_mem_map will return the actual
+ * physical page frame number.
+ */
+static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum)
+{
+	return (unsigned long)(mem_map - (section_nr_to_pfn(pnum)));
+}
+
+/*
+ * We need this if we ever free the mem_maps.  While not implemented yet,
+ * this function is included for parity with its sibling.
+ */
+static __attribute((unused))
+struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum)
+{
+	return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum);
+}
+
+static int __meminit sparse_init_one_section(struct mem_section *ms,
+		unsigned long pnum, struct page *mem_map,
+		unsigned long *pageblock_bitmap)
+{
+	if (!present_section(ms))
+		return -EINVAL;
+
+	ms->section_mem_map &= ~SECTION_MAP_MASK;
+	ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) |
+							SECTION_HAS_MEM_MAP;
+ 	ms->pageblock_flags = pageblock_bitmap;
+
+	return 1;
+}
+
+static unsigned long usemap_size(void)
+{
+	unsigned long size_bytes;
+	size_bytes = roundup(SECTION_BLOCKFLAGS_BITS, 8) / 8;
+	size_bytes = roundup(size_bytes, sizeof(unsigned long));
+	return size_bytes;
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+static unsigned long *__kmalloc_section_usemap(void)
+{
+	return kmalloc(usemap_size(), GFP_KERNEL);
+}
+#endif /* CONFIG_MEMORY_HOTPLUG */
+
+static unsigned long *__init sparse_early_usemap_alloc(unsigned long pnum)
+{
+	unsigned long *usemap;
+	struct mem_section *ms = __nr_to_section(pnum);
+	int nid = sparse_early_nid(ms);
+
+	usemap = alloc_bootmem_node(NODE_DATA(nid), usemap_size());
+	if (usemap)
+		return usemap;
+
+	/* Stupid: suppress gcc warning for SPARSEMEM && !NUMA */
+	nid = 0;
+
+	printk(KERN_WARNING "%s: allocation failed\n", __FUNCTION__);
+	return NULL;
+}
+
+#ifndef CONFIG_SPARSEMEM_VMEMMAP
+struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid)
+{
+	struct page *map;
+
+	map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION);
+	if (map)
+		return map;
+
+	map = alloc_bootmem_node(NODE_DATA(nid),
+			sizeof(struct page) * PAGES_PER_SECTION);
+	return map;
+}
+#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
+
+struct page __init *sparse_early_mem_map_alloc(unsigned long pnum)
+{
+	struct page *map;
+	struct mem_section *ms = __nr_to_section(pnum);
+	int nid = sparse_early_nid(ms);
+
+	map = sparse_mem_map_populate(pnum, nid);
+	if (map)
+		return map;
+
+	printk(KERN_ERR "%s: sparsemem memory map backing failed "
+			"some memory will not be available.\n", __FUNCTION__);
+	ms->section_mem_map = 0;
+	return NULL;
+}
+
+/*
+ * Allocate the accumulated non-linear sections, allocate a mem_map
+ * for each and record the physical to section mapping.
+ */
+void __init sparse_init(void)
+{
+	unsigned long pnum;
+	struct page *map;
+	unsigned long *usemap;
+
+	for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
+		if (!present_section_nr(pnum))
+			continue;
+
+		map = sparse_early_mem_map_alloc(pnum);
+		if (!map)
+			continue;
+
+		usemap = sparse_early_usemap_alloc(pnum);
+		if (!usemap)
+			continue;
+
+		sparse_init_one_section(__nr_to_section(pnum), pnum, map,
+								usemap);
+	}
+}
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
+						 unsigned long nr_pages)
+{
+	/* This will make the necessary allocations eventually. */
+	return sparse_mem_map_populate(pnum, nid);
+}
+static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
+{
+	return; /* XXX: Not implemented yet */
+}
+#else
+static struct page *__kmalloc_section_memmap(unsigned long nr_pages)
+{
+	struct page *page, *ret;
+	unsigned long memmap_size = sizeof(struct page) * nr_pages;
+
+	page = alloc_pages(GFP_KERNEL|__GFP_NOWARN, get_order(memmap_size));
+	if (page)
+		goto got_map_page;
+
+	ret = vmalloc(memmap_size);
+	if (ret)
+		goto got_map_ptr;
+
+	return NULL;
+got_map_page:
+	ret = (struct page *)pfn_to_kaddr(page_to_pfn(page));
+got_map_ptr:
+	memset(ret, 0, memmap_size);
+
+	return ret;
+}
+
+static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
+						  unsigned long nr_pages)
+{
+	return __kmalloc_section_memmap(nr_pages);
+}
+
+static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
+{
+	if (is_vmalloc_addr(memmap))
+		vfree(memmap);
+	else
+		free_pages((unsigned long)memmap,
+			   get_order(sizeof(struct page) * nr_pages));
+}
+#endif /* CONFIG_SPARSEMEM_VMEMMAP */
+
+/*
+ * returns the number of sections whose mem_maps were properly
+ * set.  If this is <=0, then that means that the passed-in
+ * map was not consumed and must be freed.
+ */
+int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
+			   int nr_pages)
+{
+	unsigned long section_nr = pfn_to_section_nr(start_pfn);
+	struct pglist_data *pgdat = zone->zone_pgdat;
+	struct mem_section *ms;
+	struct page *memmap;
+	unsigned long *usemap;
+	unsigned long flags;
+	int ret;
+
+	/*
+	 * no locking for this, because it does its own
+	 * plus, it does a kmalloc
+	 */
+	ret = sparse_index_init(section_nr, pgdat->node_id);
+	if (ret < 0 && ret != -EEXIST)
+		return ret;
+	memmap = kmalloc_section_memmap(section_nr, pgdat->node_id, nr_pages);
+	if (!memmap)
+		return -ENOMEM;
+	usemap = __kmalloc_section_usemap();
+	if (!usemap) {
+		__kfree_section_memmap(memmap, nr_pages);
+		return -ENOMEM;
+	}
+
+	pgdat_resize_lock(pgdat, &flags);
+
+	ms = __pfn_to_section(start_pfn);
+	if (ms->section_mem_map & SECTION_MARKED_PRESENT) {
+		ret = -EEXIST;
+		goto out;
+	}
+
+	ms->section_mem_map |= SECTION_MARKED_PRESENT;
+
+	ret = sparse_init_one_section(ms, section_nr, memmap, usemap);
+
+out:
+	pgdat_resize_unlock(pgdat, &flags);
+	if (ret <= 0) {
+		kfree(usemap);
+		__kfree_section_memmap(memmap, nr_pages);
+	}
+	return ret;
+}
+#endif