diff options
Diffstat (limited to 'mm/sparse.c')
| -rw-r--r-- | mm/sparse.c | 779 |
1 files changed, 779 insertions, 0 deletions
diff --git a/mm/sparse.c b/mm/sparse.c new file mode 100644 index 000000000..ed60f0a37 --- /dev/null +++ b/mm/sparse.c @@ -0,0 +1,779 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * sparse memory mappings. + */ +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/mmzone.h> +#include <linux/bootmem.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_virt_alloc_node(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_virt_alloc(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); + } + } +} + +/* + * 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_virt_alloc_try_nid_nopanic(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_virt_alloc_node_nopanic(size, 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); + + if (map) + return map; + + map = memblock_virt_alloc_try_nid(size, + PAGE_SIZE, __pa(MAX_DMA_ADDRESS), + BOOTMEM_ALLOC_ACCESSIBLE, nid); + 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) +{ + WARN_ON(sparsemap_buf); /* forgot to call sparse_buffer_fini()? */ + sparsemap_buf = + memblock_virt_alloc_try_nid_raw(size, PAGE_SIZE, + __pa(MAX_DMA_ADDRESS), + BOOTMEM_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; + sparse_buffer_fini(); + 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 online */ +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 */ + +/* + * 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(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; + } + +#ifdef CONFIG_DEBUG_VM + /* + * Poison uninitialized struct pages in order to catch invalid flags + * combinations. + */ + memset(memmap, PAGE_POISON_PATTERN, sizeof(struct page) * PAGES_PER_SECTION); +#endif + + 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; + + 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 */ |