diff --git a/include/linux/mm.h b/include/linux/mm.h index 5657670..1f26af5 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1642,6 +1642,7 @@ int vmemmap_populate(struct page *start_page, unsigned long pages, int node); void vmemmap_populate_print_last(void); void register_page_bootmem_memmap(unsigned long section_nr, struct page *map, unsigned long size); +void vmemmap_free(struct page *memmap, unsigned long nr_pages); enum mf_flags { MF_COUNT_INCREASED = 1 << 0, diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c index 1b7e22a..242cb28 100644 --- a/mm/sparse-vmemmap.c +++ b/mm/sparse-vmemmap.c @@ -29,6 +29,10 @@ #include #include +#ifdef CONFIG_MEMORY_HOTREMOVE +#include +#endif + /* * Allocate a block of memory to be used to back the virtual memory map * or to back the page tables that are used to create the mapping. @@ -224,3 +228,213 @@ void __init sparse_mem_maps_populate_node(struct page **map_map, vmemmap_buf_end = NULL; } } + +#ifdef CONFIG_MEMORY_HOTREMOVE +static void vmemmap_free_pages(struct page *page, int order) +{ + struct zone *zone; + unsigned long magic; + + magic = (unsigned long) page->lru.next; + if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) { + put_page_bootmem(page); + + zone = page_zone(page); + zone_span_writelock(zone); + zone->present_pages++; + zone_span_writeunlock(zone); + totalram_pages++; + } else { + if (is_vmalloc_addr(page_address(page))) + vfree(page_address(page)); + else + free_pages((unsigned long)page_address(page), order); + } +} + +static void free_pte_table(pmd_t *pmd) +{ + pte_t *pte, *pte_start; + int i; + + pte_start = (pte_t *)pmd_page_vaddr(*pmd); + for (i = 0; i < PTRS_PER_PTE; i++) { + pte = pte_start + i; + if (pte_val(*pte)) + return; + } + + /* free a pte talbe */ + vmemmap_free_pages(pmd_page(*pmd), 0); + spin_lock(&init_mm.page_table_lock); + pmd_clear(pmd); + spin_unlock(&init_mm.page_table_lock); +} + +static void free_pmd_table(pud_t *pud) +{ + pmd_t *pmd, *pmd_start; + int i; + + pmd_start = (pmd_t *)pud_page_vaddr(*pud); + for (i = 0; i < PTRS_PER_PMD; i++) { + pmd = pmd_start + i; + if (pmd_val(*pmd)) + return; + } + + /* free a pmd talbe */ + vmemmap_free_pages(pud_page(*pud), 0); + spin_lock(&init_mm.page_table_lock); + pud_clear(pud); + spin_unlock(&init_mm.page_table_lock); +} + +static void free_pud_table(pgd_t *pgd) +{ + pud_t *pud, *pud_start; + int i; + + pud_start = (pud_t *)pgd_page_vaddr(*pgd); + for (i = 0; i < PTRS_PER_PUD; i++) { + pud = pud_start + i; + if (pud_val(*pud)) + return; + } + + /* free a pud table */ + vmemmap_free_pages(pgd_page(*pgd), 0); + spin_lock(&init_mm.page_table_lock); + pgd_clear(pgd); + spin_unlock(&init_mm.page_table_lock); +} + +static int split_large_page(pte_t *kpte, unsigned long address, pte_t *pbase) +{ + struct page *page = pmd_page(*(pmd_t *)kpte); + int i = 0; + unsigned long magic; + unsigned long section_nr; + + __split_large_page(kpte, address, pbase); + __flush_tlb_all(); + + magic = (unsigned long) page->lru.next; + if (magic == SECTION_INFO) { + section_nr = pfn_to_section_nr(page_to_pfn(page)); + while (i < PTRS_PER_PMD) { + page++; + i++; + get_page_bootmem(section_nr, page, SECTION_INFO); + } + } + + return 0; +} + +static void vmemmap_pte_remove(pmd_t *pmd, unsigned long addr, unsigned long end) +{ + pte_t *pte; + unsigned long next; + + pte = pte_offset_kernel(pmd, addr); + for (; addr < end; pte++, addr += PAGE_SIZE) { + next = (addr + PAGE_SIZE) & PAGE_MASK; + if (next > end) + next = end; + + if (pte_none(*pte)) + continue; + if (IS_ALIGNED(addr, PAGE_SIZE) && + IS_ALIGNED(end, PAGE_SIZE)) { + vmemmap_free_pages(pte_page(*pte), 0); + spin_lock(&init_mm.page_table_lock); + pte_clear(&init_mm, addr, pte); + spin_unlock(&init_mm.page_table_lock); + } + } + + free_pte_table(pmd); + __flush_tlb_all(); +} + +static void vmemmap_pmd_remove(pud_t *pud, unsigned long addr, unsigned long end) +{ + unsigned long next; + pmd_t *pmd; + + pmd = pmd_offset(pud, addr); + for (; addr < end; addr = next, pmd++) { + next = pmd_addr_end(addr, end); + if (pmd_none(*pmd)) + continue; + + if (cpu_has_pse) { + unsigned long pte_base; + + if (IS_ALIGNED(addr, PMD_SIZE) && + IS_ALIGNED(next, PMD_SIZE)) { + vmemmap_free_pages(pmd_page(*pmd), + get_order(PMD_SIZE)); + spin_lock(&init_mm.page_table_lock); + pmd_clear(pmd); + spin_unlock(&init_mm.page_table_lock); + continue; + } + + /* + * We use 2M page, but we need to remove part of them, + * so split 2M page to 4K page. + */ + pte_base = get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK); + split_large_page((pte_t *)pmd, addr, (pte_t *)pte_base); + __flush_tlb_all(); + + spin_lock(&init_mm.page_table_lock); + pmd_populate_kernel(&init_mm, pmd, (pte_t *)pte_base); + spin_unlock(&init_mm.page_table_lock); + } + + vmemmap_pte_remove(pmd, addr, next); + } + + free_pmd_table(pud); + __flush_tlb_all(); +} + +static void vmemmap_pud_remove(pgd_t *pgd, unsigned long addr, unsigned long end) +{ + unsigned long next; + pud_t *pud; + + pud = pud_offset(pgd, addr); + for (; addr < end; addr = next, pud++) { + next = pud_addr_end(addr, end); + if (pud_none(*pud)) + continue; + + vmemmap_pmd_remove(pud, addr, next); + } + + free_pud_table(pgd); + __flush_tlb_all(); +} + +void vmemmap_free(struct page *memmap, unsigned long nr_pages) +{ + unsigned long addr = (unsigned long)memmap; + unsigned long end = (unsigned long)(memmap + nr_pages); + unsigned long next; + + for (; addr < end; addr = next) { + pgd_t *pgd = pgd_offset_k(addr); + + next = pgd_addr_end(addr, end); + if (!pgd_present(*pgd)) + continue; + + vmemmap_pud_remove(pgd, addr, next); + sync_global_pgds(addr, next); + } +} +#endif diff --git a/mm/sparse.c b/mm/sparse.c index fac95f2..3a16d68 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -613,12 +613,13 @@ static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid, /* 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) +static void __kfree_section_memmap(struct page *page, unsigned long nr_pages) { - return; /* XXX: Not implemented yet */ + vmemmap_free(page, nr_pages); } static void free_map_bootmem(struct page *page, unsigned long nr_pages) { + vmemmap_free(page, nr_pages); } #else static struct page *__kmalloc_section_memmap(unsigned long nr_pages)