/* * 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> /* * 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); #endif #ifdef CONFIG_SPARSEMEM_EXTREME static struct mem_section noinline *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; #ifdef NODE_NOT_IN_PAGE_FLAGS section_to_node_table[section_nr] = nid; #endif if (mem_section[root]) return -EEXIST; section = sparse_index_alloc(nid); /* * 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 becase * 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); 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_valid(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) { if (!valid_section(ms)) return -EINVAL; ms->section_mem_map &= ~SECTION_MAP_MASK; ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum); return 1; } 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 = 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); if (map) return map; printk(KERN_WARNING "%s: allocation failed\n", __FUNCTION__); ms->section_mem_map = 0; return NULL; } 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 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)); } /* * 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; for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) { if (!valid_section_nr(pnum)) continue; map = sparse_early_mem_map_alloc(pnum); if (!map) continue; sparse_init_one_section(__nr_to_section(pnum), pnum, map); } } #ifdef CONFIG_MEMORY_HOTPLUG /* * 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 flags; int ret; /* * no locking for this, because it does its own * plus, it does a kmalloc */ sparse_index_init(section_nr, pgdat->node_id); memmap = __kmalloc_section_memmap(nr_pages); 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); out: pgdat_resize_unlock(pgdat, &flags); if (ret <= 0) __kfree_section_memmap(memmap, nr_pages); return ret; } #endif