/* * 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()) { if (node_state(nid, N_HIGH_MEMORY)) section = kmalloc_node(array_size, GFP_KERNEL, nid); else section = kmalloc(array_size, GFP_KERNEL); } 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; } else 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