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/*

 * 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 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 *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 int vaddr_in_vmalloc_area(void *addr)

{

        if (addr >= (void *)VMALLOC_START &&

            addr < (void *)VMALLOC_END)

                return 1;

        return 0;

}

static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)

{

        if (vaddr_in_vmalloc_area(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