| // 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 <linux/swap.h> |
| #include <linux/swapops.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; |
| |
| /* |
| * An existing section is possible in the sub-section hotplug |
| * case. First hot-add instantiates, follow-on hot-add reuses |
| * the existing section. |
| * |
| * The mem_hotplug_lock resolves the apparent race below. |
| */ |
| if (mem_section[root]) |
| return 0; |
| |
| 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 |
| unsigned long __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 |
| unsigned long __section_nr(struct mem_section *ms) |
| { |
| return (unsigned long)(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. |
| */ |
| unsigned long __highest_present_section_nr; |
| static void section_mark_present(struct mem_section *ms) |
| { |
| unsigned long 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 unsigned long next_present_section_nr(unsigned long 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); |
| } |
| |
| static void subsection_mask_set(unsigned long *map, unsigned long pfn, |
| unsigned long nr_pages) |
| { |
| int idx = subsection_map_index(pfn); |
| int end = subsection_map_index(pfn + nr_pages - 1); |
| |
| bitmap_set(map, idx, end - idx + 1); |
| } |
| |
| void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages) |
| { |
| int end_sec = pfn_to_section_nr(pfn + nr_pages - 1); |
| unsigned long nr, start_sec = pfn_to_section_nr(pfn); |
| |
| if (!nr_pages) |
| return; |
| |
| for (nr = start_sec; nr <= end_sec; nr++) { |
| struct mem_section *ms; |
| unsigned long pfns; |
| |
| pfns = min(nr_pages, PAGES_PER_SECTION |
| - (pfn & ~PAGE_SECTION_MASK)); |
| ms = __nr_to_section(nr); |
| subsection_mask_set(ms->usage->subsection_map, pfn, pfns); |
| |
| pr_debug("%s: sec: %lu pfns: %lu set(%d, %d)\n", __func__, nr, |
| pfns, subsection_map_index(pfn), |
| subsection_map_index(pfn + pfns - 1)); |
| |
| pfn += pfns; |
| nr_pages -= pfns; |
| } |
| } |
| |
| /* 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, |
| struct mem_section_usage *usage, unsigned long flags) |
| { |
| ms->section_mem_map &= ~SECTION_MAP_MASK; |
| ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) |
| | SECTION_HAS_MEM_MAP | flags; |
| ms->usage = usage; |
| } |
| |
| static unsigned long usemap_size(void) |
| { |
| return BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS) * sizeof(unsigned long); |
| } |
| |
| size_t mem_section_usage_size(void) |
| { |
| return sizeof(struct mem_section_usage) + usemap_size(); |
| } |
| |
| #ifdef CONFIG_MEMORY_HOTREMOVE |
| static struct mem_section_usage * __init |
| sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat, |
| unsigned long size) |
| { |
| struct mem_section_usage *usage; |
| unsigned long goal, limit; |
| 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: |
| usage = memblock_alloc_try_nid(size, SMP_CACHE_BYTES, goal, limit, nid); |
| if (!usage && limit) { |
| limit = 0; |
| goto again; |
| } |
| return usage; |
| } |
| |
| static void __init check_usemap_section_nr(int nid, |
| struct mem_section_usage *usage) |
| { |
| 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(usage) >> 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 struct mem_section_usage * __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, |
| struct mem_section_usage *usage) |
| { |
| } |
| #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 *__populate_section_memmap(unsigned long pfn, |
| unsigned long nr_pages, 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 inline void __meminit sparse_buffer_free(unsigned long size) |
| { |
| WARN_ON(!sparsemap_buf || size == 0); |
| memblock_free_early(__pa(sparsemap_buf), size); |
| } |
| |
| 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) |
| sparse_buffer_free(size); |
| sparsemap_buf = NULL; |
| } |
| |
| void * __meminit sparse_buffer_alloc(unsigned long size) |
| { |
| void *ptr = NULL; |
| |
| if (sparsemap_buf) { |
| ptr = (void *) roundup((unsigned long)sparsemap_buf, size); |
| if (ptr + size > sparsemap_buf_end) |
| ptr = NULL; |
| else { |
| /* Free redundant aligned space */ |
| if ((unsigned long)(ptr - sparsemap_buf) > 0) |
| sparse_buffer_free((unsigned long)(ptr - sparsemap_buf)); |
| 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) |
| { |
| struct mem_section_usage *usage; |
| unsigned long pnum; |
| struct page *map; |
| |
| usage = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nid), |
| mem_section_usage_size() * map_count); |
| if (!usage) { |
| 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) { |
| unsigned long pfn = section_nr_to_pfn(pnum); |
| |
| if (pnum >= pnum_end) |
| break; |
| |
| map = __populate_section_memmap(pfn, PAGES_PER_SECTION, |
| 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, usage); |
| sparse_init_one_section(__nr_to_section(pnum), pnum, map, usage, |
| SECTION_IS_EARLY); |
| usage = (void *) usage + mem_section_usage_size(); |
| } |
| 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 struct page * __meminit populate_section_memmap(unsigned long pfn, |
| unsigned long nr_pages, int nid, struct vmem_altmap *altmap) |
| { |
| return __populate_section_memmap(pfn, nr_pages, nid, altmap); |
| } |
| |
| static void depopulate_section_memmap(unsigned long pfn, unsigned long nr_pages, |
| struct vmem_altmap *altmap) |
| { |
| unsigned long start = (unsigned long) pfn_to_page(pfn); |
| unsigned long end = start + nr_pages * sizeof(struct page); |
| |
| 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 |
| struct page * __meminit populate_section_memmap(unsigned long pfn, |
| unsigned long nr_pages, int nid, struct vmem_altmap *altmap) |
| { |
| 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 void depopulate_section_memmap(unsigned long pfn, unsigned long nr_pages, |
| struct vmem_altmap *altmap) |
| { |
| struct page *memmap = pfn_to_page(pfn); |
| |
| 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 */ |
| |
| static void section_deactivate(unsigned long pfn, unsigned long nr_pages, |
| struct vmem_altmap *altmap) |
| { |
| DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 }; |
| DECLARE_BITMAP(tmp, SUBSECTIONS_PER_SECTION) = { 0 }; |
| struct mem_section *ms = __pfn_to_section(pfn); |
| bool section_is_early = early_section(ms); |
| struct page *memmap = NULL; |
| bool empty; |
| unsigned long *subsection_map = ms->usage |
| ? &ms->usage->subsection_map[0] : NULL; |
| |
| subsection_mask_set(map, pfn, nr_pages); |
| if (subsection_map) |
| bitmap_and(tmp, map, subsection_map, SUBSECTIONS_PER_SECTION); |
| |
| if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION), |
| "section already deactivated (%#lx + %ld)\n", |
| pfn, nr_pages)) |
| return; |
| |
| /* |
| * There are 3 cases to handle across two configurations |
| * (SPARSEMEM_VMEMMAP={y,n}): |
| * |
| * 1/ deactivation of a partial hot-added section (only possible |
| * in the SPARSEMEM_VMEMMAP=y case). |
| * a/ section was present at memory init |
| * b/ section was hot-added post memory init |
| * 2/ deactivation of a complete hot-added section |
| * 3/ deactivation of a complete section from memory init |
| * |
| * For 1/, when subsection_map does not empty we will not be |
| * freeing the usage map, but still need to free the vmemmap |
| * range. |
| * |
| * For 2/ and 3/ the SPARSEMEM_VMEMMAP={y,n} cases are unified |
| */ |
| bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION); |
| empty = bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION); |
| if (empty) { |
| unsigned long section_nr = pfn_to_section_nr(pfn); |
| |
| /* |
| * When removing an early section, the usage map is kept (as the |
| * usage maps of other sections fall into the same page). It |
| * will be re-used when re-adding the section - which is then no |
| * longer an early section. If the usage map is PageReserved, it |
| * was allocated during boot. |
| */ |
| if (!PageReserved(virt_to_page(ms->usage))) { |
| kfree(ms->usage); |
| ms->usage = NULL; |
| } |
| memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); |
| /* |
| * Mark the section invalid so that valid_section() |
| * return false. This prevents code from dereferencing |
| * ms->usage array. |
| */ |
| ms->section_mem_map &= ~SECTION_HAS_MEM_MAP; |
| } |
| |
| if (section_is_early && memmap) |
| free_map_bootmem(memmap); |
| else |
| depopulate_section_memmap(pfn, nr_pages, altmap); |
| |
| if (empty) |
| ms->section_mem_map = (unsigned long)NULL; |
| } |
| |
| static struct page * __meminit section_activate(int nid, unsigned long pfn, |
| unsigned long nr_pages, struct vmem_altmap *altmap) |
| { |
| DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 }; |
| struct mem_section *ms = __pfn_to_section(pfn); |
| struct mem_section_usage *usage = NULL; |
| unsigned long *subsection_map; |
| struct page *memmap; |
| int rc = 0; |
| |
| subsection_mask_set(map, pfn, nr_pages); |
| |
| if (!ms->usage) { |
| usage = kzalloc(mem_section_usage_size(), GFP_KERNEL); |
| if (!usage) |
| return ERR_PTR(-ENOMEM); |
| ms->usage = usage; |
| } |
| subsection_map = &ms->usage->subsection_map[0]; |
| |
| if (bitmap_empty(map, SUBSECTIONS_PER_SECTION)) |
| rc = -EINVAL; |
| else if (bitmap_intersects(map, subsection_map, SUBSECTIONS_PER_SECTION)) |
| rc = -EEXIST; |
| else |
| bitmap_or(subsection_map, map, subsection_map, |
| SUBSECTIONS_PER_SECTION); |
| |
| if (rc) { |
| if (usage) |
| ms->usage = NULL; |
| kfree(usage); |
| return ERR_PTR(rc); |
| } |
| |
| /* |
| * The early init code does not consider partially populated |
| * initial sections, it simply assumes that memory will never be |
| * referenced. If we hot-add memory into such a section then we |
| * do not need to populate the memmap and can simply reuse what |
| * is already there. |
| */ |
| if (nr_pages < PAGES_PER_SECTION && early_section(ms)) |
| return pfn_to_page(pfn); |
| |
| memmap = populate_section_memmap(pfn, nr_pages, nid, altmap); |
| if (!memmap) { |
| section_deactivate(pfn, nr_pages, altmap); |
| return ERR_PTR(-ENOMEM); |
| } |
| |
| return memmap; |
| } |
| |
| /** |
| * sparse_add_section - add a memory section, or populate an existing one |
| * @nid: The node to add section on |
| * @start_pfn: start pfn of the memory range |
| * @nr_pages: number of pfns to add in the section |
| * @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_section(int nid, unsigned long start_pfn, |
| unsigned long nr_pages, struct vmem_altmap *altmap) |
| { |
| unsigned long section_nr = pfn_to_section_nr(start_pfn); |
| struct mem_section *ms; |
| struct page *memmap; |
| int ret; |
| |
| ret = sparse_index_init(section_nr, nid); |
| if (ret < 0) |
| return ret; |
| |
| memmap = section_activate(nid, start_pfn, nr_pages, altmap); |
| if (IS_ERR(memmap)) |
| return PTR_ERR(memmap); |
| |
| /* |
| * Poison uninitialized struct pages in order to catch invalid flags |
| * combinations. |
| */ |
| page_init_poison(memmap, sizeof(struct page) * nr_pages); |
| |
| ms = __nr_to_section(section_nr); |
| set_section_nid(section_nr, nid); |
| section_mark_present(ms); |
| |
| /* Align memmap to section boundary in the subsection case */ |
| if (section_nr_to_pfn(section_nr) != start_pfn) |
| memmap = pfn_to_kaddr(section_nr_to_pfn(section_nr)); |
| sparse_init_one_section(ms, section_nr, memmap, ms->usage, 0); |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_MEMORY_FAILURE |
| static void clear_hwpoisoned_pages(struct page *memmap, int nr_pages) |
| { |
| int i; |
| |
| /* |
| * 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])) { |
| num_poisoned_pages_dec(); |
| ClearPageHWPoison(&memmap[i]); |
| } |
| } |
| } |
| #else |
| static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages) |
| { |
| } |
| #endif |
| |
| void sparse_remove_section(struct mem_section *ms, unsigned long pfn, |
| unsigned long nr_pages, unsigned long map_offset, |
| struct vmem_altmap *altmap) |
| { |
| clear_hwpoisoned_pages(pfn_to_page(pfn) + map_offset, |
| nr_pages - map_offset); |
| section_deactivate(pfn, nr_pages, altmap); |
| } |
| #endif /* CONFIG_MEMORY_HOTPLUG */ |