// SPDX-License-Identifier: GPL-2.0 /* * sparse memory mappings. */ #include <linux/mm.h> #include <linux/slab.h> #include <linux/mmzone.h> #include <linux/memblock.h> #include <linux/compiler.h> #include <linux/highmem.h> #include <linux/export.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; #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(const 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 noinline struct mem_section __ref *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 = kzalloc_node(array_size, GFP_KERNEL, nid); } else { section = memblock_alloc_node(array_size, SMP_CACHE_BYTES, nid); if (!section) panic("%s: Failed to allocate %lu bytes nid=%d\n", __func__, array_size, nid); } return section; } static int __meminit sparse_index_init(unsigned long section_nr, int nid) { unsigned long root = SECTION_NR_TO_ROOT(section_nr); struct mem_section *section; if (mem_section[root]) return -EEXIST; section = sparse_index_alloc(nid); if (!section) return -ENOMEM; mem_section[root] = section; return 0; } #else /* !SPARSEMEM_EXTREME */ static inline int sparse_index_init(unsigned long section_nr, int nid) { return 0; } #endif #ifdef CONFIG_SPARSEMEM_EXTREME int __section_nr(struct mem_section* ms) { unsigned long root_nr; struct mem_section *root = NULL; 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; } VM_BUG_ON(!root); return (root_nr * SECTIONS_PER_ROOT) + (ms - root); } #else int __section_nr(struct mem_section* ms) { return (int)(ms - mem_section[0]); } #endif /* * 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; } } /* * There are a number of times that we loop over NR_MEM_SECTIONS, * looking for section_present() on each. But, when we have very * large physical address spaces, NR_MEM_SECTIONS can also be * very large which makes the loops quite long. * * Keeping track of this gives us an easy way to break out of * those loops early. */ int __highest_present_section_nr; static void section_mark_present(struct mem_section *ms) { int section_nr = __section_nr(ms); if (section_nr > __highest_present_section_nr) __highest_present_section_nr = section_nr; ms->section_mem_map |= SECTION_MARKED_PRESENT; } static inline int next_present_section_nr(int section_nr) { do { section_nr++; if (present_section_nr(section_nr)) return section_nr; } while ((section_nr <= __highest_present_section_nr)); return -1; } #define for_each_present_section_nr(start, section_nr) \ for (section_nr = next_present_section_nr(start-1); \ ((section_nr != -1) && \ (section_nr <= __highest_present_section_nr)); \ section_nr = next_present_section_nr(section_nr)) static inline unsigned long first_present_section_nr(void) { return next_present_section_nr(-1); } /* Record a memory area against a node. */ void __init memory_present(int nid, unsigned long start, unsigned long end) { unsigned long pfn; #ifdef CONFIG_SPARSEMEM_EXTREME if (unlikely(!mem_section)) { unsigned long size, align; size = sizeof(struct mem_section*) * NR_SECTION_ROOTS; align = 1 << (INTERNODE_CACHE_SHIFT); mem_section = memblock_alloc(size, align); if (!mem_section) panic("%s: Failed to allocate %lu bytes align=0x%lx\n", __func__, size, align); } #endif 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_IS_ONLINE; section_mark_present(ms); } } } /* * Mark all memblocks as present using memory_present(). This is a * convienence function that is useful for a number of arches * to mark all of the systems memory as present during initialization. */ void __init memblocks_present(void) { struct memblock_region *reg; for_each_memblock(memory, reg) { memory_present(memblock_get_region_node(reg), memblock_region_memory_base_pfn(reg), memblock_region_memory_end_pfn(reg)); } } /* * 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) { unsigned long coded_mem_map = (unsigned long)(mem_map - (section_nr_to_pfn(pnum))); BUILD_BUG_ON(SECTION_MAP_LAST_BIT > (1UL<<PFN_SECTION_SHIFT)); BUG_ON(coded_mem_map & ~SECTION_MAP_MASK); return coded_mem_map; } /* * 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 void __meminit sparse_init_one_section(struct mem_section *ms, unsigned long pnum, struct page *mem_map, unsigned long *pageblock_bitmap) { 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; } unsigned long usemap_size(void) { return BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS) * sizeof(unsigned long); } #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_usemaps_alloc_pgdat_section(struct pglist_data *pgdat, unsigned long size) { unsigned long goal, limit; unsigned long *p; int nid; /* * A page may contain usemaps for other sections preventing the * page being freed and making a section unremovable while * other sections referencing the usemap remain 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. */ goal = __pa(pgdat) & (PAGE_SECTION_MASK << PAGE_SHIFT); limit = goal + (1UL << PA_SECTION_SHIFT); nid = early_pfn_to_nid(goal >> PAGE_SHIFT); again: p = memblock_alloc_try_nid(size, SMP_CACHE_BYTES, goal, limit, nid); if (!p && limit) { limit = 0; goto again; } return p; } static void __init check_usemap_section_nr(int nid, unsigned long *usemap) { unsigned long usemap_snr, pgdat_snr; static unsigned long old_usemap_snr; static unsigned long old_pgdat_snr; struct pglist_data *pgdat = NODE_DATA(nid); int usemap_nid; /* First call */ if (!old_usemap_snr) { old_usemap_snr = NR_MEM_SECTIONS; old_pgdat_snr = NR_MEM_SECTIONS; } 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) { pr_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. */ pr_info("Section %ld and %ld (node %d) have a circular dependency on usemap and pgdat allocations\n", usemap_snr, pgdat_snr, nid); } #else static unsigned long * __init sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat, unsigned long size) { return memblock_alloc_node(size, SMP_CACHE_BYTES, pgdat->node_id); } static void __init check_usemap_section_nr(int nid, unsigned long *usemap) { } #endif /* CONFIG_MEMORY_HOTREMOVE */ #ifdef CONFIG_SPARSEMEM_VMEMMAP static unsigned long __init section_map_size(void) { return ALIGN(sizeof(struct page) * PAGES_PER_SECTION, PMD_SIZE); } #else static unsigned long __init section_map_size(void) { return PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION); } struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid, struct vmem_altmap *altmap) { unsigned long size = section_map_size(); struct page *map = sparse_buffer_alloc(size); phys_addr_t addr = __pa(MAX_DMA_ADDRESS); if (map) return map; map = memblock_alloc_try_nid(size, PAGE_SIZE, addr, MEMBLOCK_ALLOC_ACCESSIBLE, nid); if (!map) panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d from=%pa\n", __func__, size, PAGE_SIZE, nid, &addr); return map; } #endif /* !CONFIG_SPARSEMEM_VMEMMAP */ static void *sparsemap_buf __meminitdata; static void *sparsemap_buf_end __meminitdata; static void __init sparse_buffer_init(unsigned long size, int nid) { phys_addr_t addr = __pa(MAX_DMA_ADDRESS); WARN_ON(sparsemap_buf); /* forgot to call sparse_buffer_fini()? */ sparsemap_buf = memblock_alloc_try_nid_raw(size, PAGE_SIZE, addr, MEMBLOCK_ALLOC_ACCESSIBLE, nid); sparsemap_buf_end = sparsemap_buf + size; } static void __init sparse_buffer_fini(void) { unsigned long size = sparsemap_buf_end - sparsemap_buf; if (sparsemap_buf && size > 0) memblock_free_early(__pa(sparsemap_buf), size); sparsemap_buf = NULL; } void * __meminit sparse_buffer_alloc(unsigned long size) { void *ptr = NULL; if (sparsemap_buf) { ptr = PTR_ALIGN(sparsemap_buf, size); if (ptr + size > sparsemap_buf_end) ptr = NULL; else sparsemap_buf = ptr + size; } return ptr; } void __weak __meminit vmemmap_populate_print_last(void) { } /* * Initialize sparse on a specific node. The node spans [pnum_begin, pnum_end) * And number of present sections in this node is map_count. */ static void __init sparse_init_nid(int nid, unsigned long pnum_begin, unsigned long pnum_end, unsigned long map_count) { unsigned long pnum, usemap_longs, *usemap; struct page *map; usemap_longs = BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS); usemap = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nid), usemap_size() * map_count); if (!usemap) { pr_err("%s: node[%d] usemap allocation failed", __func__, nid); goto failed; } sparse_buffer_init(map_count * section_map_size(), nid); for_each_present_section_nr(pnum_begin, pnum) { if (pnum >= pnum_end) break; map = sparse_mem_map_populate(pnum, nid, NULL); if (!map) { pr_err("%s: node[%d] memory map backing failed. Some memory will not be available.", __func__, nid); pnum_begin = pnum; goto failed; } check_usemap_section_nr(nid, usemap); sparse_init_one_section(__nr_to_section(pnum), pnum, map, usemap); usemap += usemap_longs; } sparse_buffer_fini(); return; failed: /* We failed to allocate, mark all the following pnums as not present */ for_each_present_section_nr(pnum_begin, pnum) { struct mem_section *ms; if (pnum >= pnum_end) break; ms = __nr_to_section(pnum); ms->section_mem_map = 0; } } /* * 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_begin = first_present_section_nr(); int nid_begin = sparse_early_nid(__nr_to_section(pnum_begin)); unsigned long pnum_end, map_count = 1; /* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */ set_pageblock_order(); for_each_present_section_nr(pnum_begin + 1, pnum_end) { int nid = sparse_early_nid(__nr_to_section(pnum_end)); if (nid == nid_begin) { map_count++; continue; } /* Init node with sections in range [pnum_begin, pnum_end) */ sparse_init_nid(nid_begin, pnum_begin, pnum_end, map_count); nid_begin = nid; pnum_begin = pnum_end; map_count = 1; } /* cover the last node */ sparse_init_nid(nid_begin, pnum_begin, pnum_end, map_count); vmemmap_populate_print_last(); } #ifdef CONFIG_MEMORY_HOTPLUG /* Mark all memory sections within the pfn range as online */ void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn) { unsigned long pfn; for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { unsigned long section_nr = pfn_to_section_nr(pfn); struct mem_section *ms; /* onlining code should never touch invalid ranges */ if (WARN_ON(!valid_section_nr(section_nr))) continue; ms = __nr_to_section(section_nr); ms->section_mem_map |= SECTION_IS_ONLINE; } } #ifdef CONFIG_MEMORY_HOTREMOVE /* Mark all memory sections within the pfn range as offline */ void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn) { unsigned long pfn; for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { unsigned long section_nr = pfn_to_section_nr(pfn); struct mem_section *ms; /* * TODO this needs some double checking. Offlining code makes * sure to check pfn_valid but those checks might be just bogus */ if (WARN_ON(!valid_section_nr(section_nr))) continue; ms = __nr_to_section(section_nr); ms->section_mem_map &= ~SECTION_IS_ONLINE; } } #endif #ifdef CONFIG_SPARSEMEM_VMEMMAP static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid, struct vmem_altmap *altmap) { /* This will make the necessary allocations eventually. */ return sparse_mem_map_populate(pnum, nid, altmap); } static void __kfree_section_memmap(struct page *memmap, struct vmem_altmap *altmap) { unsigned long start = (unsigned long)memmap; unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION); vmemmap_free(start, end, altmap); } static void free_map_bootmem(struct page *memmap) { unsigned long start = (unsigned long)memmap; unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION); vmemmap_free(start, end, NULL); } #else static struct page *__kmalloc_section_memmap(void) { struct page *page, *ret; unsigned long memmap_size = sizeof(struct page) * PAGES_PER_SECTION; 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: return ret; } static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid, struct vmem_altmap *altmap) { return __kmalloc_section_memmap(); } static void __kfree_section_memmap(struct page *memmap, struct vmem_altmap *altmap) { if (is_vmalloc_addr(memmap)) vfree(memmap); else free_pages((unsigned long)memmap, get_order(sizeof(struct page) * PAGES_PER_SECTION)); } static void free_map_bootmem(struct page *memmap) { unsigned long maps_section_nr, removing_section_nr, i; unsigned long magic, nr_pages; struct page *page = virt_to_page(memmap); nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page)) >> PAGE_SHIFT; for (i = 0; i < nr_pages; i++, page++) { magic = (unsigned long) page->freelist; BUG_ON(magic == NODE_INFO); maps_section_nr = pfn_to_section_nr(page_to_pfn(page)); removing_section_nr = page_private(page); /* * 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 */ /** * sparse_add_one_section - add a memory section * @nid: The node to add section on * @start_pfn: start pfn of the memory range * @altmap: device page map * * This is only intended for hotplug. * * Return: * * 0 - On success. * * -EEXIST - Section has been present. * * -ENOMEM - Out of memory. */ int __meminit sparse_add_one_section(int nid, unsigned long start_pfn, struct vmem_altmap *altmap) { unsigned long section_nr = pfn_to_section_nr(start_pfn); struct mem_section *ms; struct page *memmap; unsigned long *usemap; int ret; /* * no locking for this, because it does its own * plus, it does a kmalloc */ ret = sparse_index_init(section_nr, nid); if (ret < 0 && ret != -EEXIST) return ret; ret = 0; memmap = kmalloc_section_memmap(section_nr, nid, altmap); if (!memmap) return -ENOMEM; usemap = __kmalloc_section_usemap(); if (!usemap) { __kfree_section_memmap(memmap, altmap); return -ENOMEM; } ms = __pfn_to_section(start_pfn); if (ms->section_mem_map & SECTION_MARKED_PRESENT) { ret = -EEXIST; goto out; } /* * Poison uninitialized struct pages in order to catch invalid flags * combinations. */ page_init_poison(memmap, sizeof(struct page) * PAGES_PER_SECTION); section_mark_present(ms); sparse_init_one_section(ms, section_nr, memmap, usemap); out: if (ret < 0) { kfree(usemap); __kfree_section_memmap(memmap, altmap); } return ret; } #ifdef CONFIG_MEMORY_FAILURE static void clear_hwpoisoned_pages(struct page *memmap, int nr_pages) { int i; if (!memmap) return; /* * A further optimization is to have per section refcounted * num_poisoned_pages. But that would need more space per memmap, so * for now just do a quick global check to speed up this routine in the * absence of bad pages. */ if (atomic_long_read(&num_poisoned_pages) == 0) return; for (i = 0; i < nr_pages; i++) { if (PageHWPoison(&memmap[i])) { atomic_long_sub(1, &num_poisoned_pages); ClearPageHWPoison(&memmap[i]); } } } #else static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages) { } #endif static void free_section_usemap(struct page *memmap, unsigned long *usemap, struct vmem_altmap *altmap) { struct page *usemap_page; if (!usemap) return; usemap_page = virt_to_page(usemap); /* * Check to see if allocation came from hot-plug-add */ if (PageSlab(usemap_page) || PageCompound(usemap_page)) { kfree(usemap); if (memmap) __kfree_section_memmap(memmap, altmap); 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) free_map_bootmem(memmap); } void sparse_remove_one_section(struct mem_section *ms, unsigned long map_offset, struct vmem_altmap *altmap) { 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; } clear_hwpoisoned_pages(memmap + map_offset, PAGES_PER_SECTION - map_offset); free_section_usemap(memmap, usemap, altmap); } #endif /* CONFIG_MEMORY_HOTPLUG */