diff options
Diffstat (limited to 'mm/sparse.c')
| -rw-r--r-- | mm/sparse.c | 636 |
1 files changed, 636 insertions, 0 deletions
diff --git a/mm/sparse.c b/mm/sparse.c new file mode 100644 index 0000000..083f5b6 --- /dev/null +++ b/mm/sparse.c @@ -0,0 +1,636 @@ +/* + * 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 "internal.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); +} + +/* Validate the physical addressing limitations of the model */ +void __meminit mminit_validate_memmodel_limits(unsigned long *start_pfn, + unsigned long *end_pfn) +{ + unsigned long max_sparsemem_pfn = 1UL << (MAX_PHYSMEM_BITS-PAGE_SHIFT); + + /* + * Sanity checks - do not allow an architecture to pass + * in larger pfns than the maximum scope of sparsemem: + */ + if (*start_pfn > max_sparsemem_pfn) { + mminit_dprintk(MMINIT_WARNING, "pfnvalidation", + "Start of range %lu -> %lu exceeds SPARSEMEM max %lu\n", + *start_pfn, *end_pfn, max_sparsemem_pfn); + WARN_ON_ONCE(1); + *start_pfn = max_sparsemem_pfn; + *end_pfn = max_sparsemem_pfn; + } + + if (*end_pfn > max_sparsemem_pfn) { + mminit_dprintk(MMINIT_WARNING, "pfnvalidation", + "End of range %lu -> %lu exceeds SPARSEMEM max %lu\n", + *start_pfn, *end_pfn, max_sparsemem_pfn); + WARN_ON_ONCE(1); + *end_pfn = max_sparsemem_pfn; + } +} + +/* 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; + mminit_validate_memmodel_limits(&start, &end); + 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; + + mminit_validate_memmodel_limits(&start_pfn, &end_pfn); + 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))); +} + +/* + * Decode mem_map from the coded memmap + */ +struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum) +{ + /* mask off the extra low bits of information */ + coded_mem_map &= SECTION_MAP_MASK; + 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; +} + +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 */ + +#ifdef CONFIG_MEMORY_HOTREMOVE +static unsigned long * __init +sparse_early_usemap_alloc_pgdat_section(struct pglist_data *pgdat) +{ + unsigned long section_nr; + + /* + * A page may contain usemaps for other sections preventing the + * page being freed and making a section unremovable while + * other sections referencing the usemap retmain active. Similarly, + * a pgdat can prevent a section being removed. If section A + * contains a pgdat and section B contains the usemap, both + * sections become inter-dependent. This allocates usemaps + * from the same section as the pgdat where possible to avoid + * this problem. + */ + section_nr = pfn_to_section_nr(__pa(pgdat) >> PAGE_SHIFT); + return alloc_bootmem_section(usemap_size(), section_nr); +} + +static void __init check_usemap_section_nr(int nid, unsigned long *usemap) +{ + unsigned long usemap_snr, pgdat_snr; + static unsigned long old_usemap_snr = NR_MEM_SECTIONS; + static unsigned long old_pgdat_snr = NR_MEM_SECTIONS; + struct pglist_data *pgdat = NODE_DATA(nid); + int usemap_nid; + + usemap_snr = pfn_to_section_nr(__pa(usemap) >> PAGE_SHIFT); + pgdat_snr = pfn_to_section_nr(__pa(pgdat) >> PAGE_SHIFT); + if (usemap_snr == pgdat_snr) + return; + + if (old_usemap_snr == usemap_snr && old_pgdat_snr == pgdat_snr) + /* skip redundant message */ + return; + + old_usemap_snr = usemap_snr; + old_pgdat_snr = pgdat_snr; + + usemap_nid = sparse_early_nid(__nr_to_section(usemap_snr)); + if (usemap_nid != nid) { + printk(KERN_INFO + "node %d must be removed before remove section %ld\n", + nid, usemap_snr); + return; + } + /* + * There is a circular dependency. + * Some platforms allow un-removable section because they will just + * gather other removable sections for dynamic partitioning. + * Just notify un-removable section's number here. + */ + printk(KERN_INFO "Section %ld and %ld (node %d)", usemap_snr, + pgdat_snr, nid); + printk(KERN_CONT + " have a circular dependency on usemap and pgdat allocations\n"); +} +#else +static unsigned long * __init +sparse_early_usemap_alloc_pgdat_section(struct pglist_data *pgdat) +{ + return NULL; +} + +static void __init check_usemap_section_nr(int nid, unsigned long *usemap) +{ +} +#endif /* CONFIG_MEMORY_HOTREMOVE */ + +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 = sparse_early_usemap_alloc_pgdat_section(NODE_DATA(nid)); + if (usemap) + return usemap; + + usemap = alloc_bootmem_node(NODE_DATA(nid), usemap_size()); + if (usemap) { + check_usemap_section_nr(nid, usemap); + return usemap; + } + + /* Stupid: suppress gcc warning for SPARSEMEM && !NUMA */ + nid = 0; + + printk(KERN_WARNING "%s: allocation failed\n", __func__); + 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_pages_node(NODE_DATA(nid), + PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION)); + return map; +} +#endif /* !CONFIG_SPARSEMEM_VMEMMAP */ + +static 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", __func__); + ms->section_mem_map = 0; + return NULL; +} + +void __attribute__((weak)) __meminit vmemmap_populate_print_last(void) +{ +} +/* + * 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; + unsigned long **usemap_map; + int size; + + /* + * map is using big page (aka 2M in x86 64 bit) + * usemap is less one page (aka 24 bytes) + * so alloc 2M (with 2M align) and 24 bytes in turn will + * make next 2M slip to one more 2M later. + * then in big system, the memory will have a lot of holes... + * here try to allocate 2M pages continously. + * + * powerpc need to call sparse_init_one_section right after each + * sparse_early_mem_map_alloc, so allocate usemap_map at first. + */ + size = sizeof(unsigned long *) * NR_MEM_SECTIONS; + usemap_map = alloc_bootmem(size); + if (!usemap_map) + panic("can not allocate usemap_map\n"); + + for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) { + if (!present_section_nr(pnum)) + continue; + usemap_map[pnum] = sparse_early_usemap_alloc(pnum); + } + + for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) { + if (!present_section_nr(pnum)) + continue; + + usemap = usemap_map[pnum]; + if (!usemap) + continue; + + map = sparse_early_mem_map_alloc(pnum); + if (!map) + continue; + + sparse_init_one_section(__nr_to_section(pnum), pnum, map, + usemap); + } + + vmemmap_populate_print_last(); + + free_bootmem(__pa(usemap_map), size); +} + +#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 */ +} +static void free_map_bootmem(struct page *page, unsigned long nr_pages) +{ +} +#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)); +} + +static void free_map_bootmem(struct page *page, unsigned long nr_pages) +{ + unsigned long maps_section_nr, removing_section_nr, i; + int magic; + + for (i = 0; i < nr_pages; i++, page++) { + magic = atomic_read(&page->_mapcount); + + BUG_ON(magic == NODE_INFO); + + maps_section_nr = pfn_to_section_nr(page_to_pfn(page)); + removing_section_nr = page->private; + + /* + * When this function is called, the removing section is + * logical offlined state. This means all pages are isolated + * from page allocator. If removing section's memmap is placed + * on the same section, it must not be freed. + * If it is freed, page allocator may allocate it which will + * be removed physically soon. + */ + if (maps_section_nr != removing_section_nr) + put_page_bootmem(page); + } +} +#endif /* CONFIG_SPARSEMEM_VMEMMAP */ + +static void free_section_usemap(struct page *memmap, unsigned long *usemap) +{ + struct page *usemap_page; + unsigned long nr_pages; + + if (!usemap) + return; + + usemap_page = virt_to_page(usemap); + /* + * Check to see if allocation came from hot-plug-add + */ + if (PageSlab(usemap_page)) { + kfree(usemap); + if (memmap) + __kfree_section_memmap(memmap, PAGES_PER_SECTION); + return; + } + + /* + * The usemap came from bootmem. This is packed with other usemaps + * on the section which has pgdat at boot time. Just keep it as is now. + */ + + if (memmap) { + struct page *memmap_page; + memmap_page = virt_to_page(memmap); + + nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page)) + >> PAGE_SHIFT; + + free_map_bootmem(memmap_page, nr_pages); + } +} + +/* + * 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 __meminit 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; +} + +void sparse_remove_one_section(struct zone *zone, struct mem_section *ms) +{ + struct page *memmap = NULL; + unsigned long *usemap = NULL; + + if (ms->section_mem_map) { + usemap = ms->pageblock_flags; + memmap = sparse_decode_mem_map(ms->section_mem_map, + __section_nr(ms)); + ms->section_mem_map = 0; + ms->pageblock_flags = NULL; + } + + free_section_usemap(memmap, usemap); +} +#endif |
