[mirror_ubuntu-kernels.git] / mm / sparse-vmemmap.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Virtual Memory Map support
 *
 * (C) 2007 sgi. Christoph Lameter.
 *
 * Virtual memory maps allow VM primitives pfn_to_page, page_to_pfn,
 * virt_to_page, page_address() to be implemented as a base offset
 * calculation without memory access.
 *
 * However, virtual mappings need a page table and TLBs. Many Linux
 * architectures already map their physical space using 1-1 mappings
 * via TLBs. For those arches the virtual memory map is essentially
 * for free if we use the same page size as the 1-1 mappings. In that
 * case the overhead consists of a few additional pages that are
 * allocated to create a view of memory for vmemmap.
 *
 * The architecture is expected to provide a vmemmap_populate() function
 * to instantiate the mapping.
 */
#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/memblock.h>
#include <linux/memremap.h>
#include <linux/highmem.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/vmalloc.h>
#include <linux/sched.h>
#include <linux/pgtable.h>
#include <linux/bootmem_info.h>

#include <asm/dma.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>

#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
/**
 * struct vmemmap_remap_walk - walk vmemmap page table
 *
 * @remap_pte:		called for each lowest-level entry (PTE).
 * @nr_walked:		the number of walked pte.
 * @reuse_page:		the page which is reused for the tail vmemmap pages.
 * @reuse_addr:		the virtual address of the @reuse_page page.
 * @vmemmap_pages:	the list head of the vmemmap pages that can be freed
 *			or is mapped from.
 */
struct vmemmap_remap_walk {
	void (*remap_pte)(pte_t *pte, unsigned long addr,
			  struct vmemmap_remap_walk *walk);
	unsigned long nr_walked;
	struct page *reuse_page;
	unsigned long reuse_addr;
	struct list_head *vmemmap_pages;
};

static int __split_vmemmap_huge_pmd(pmd_t *pmd, unsigned long start)
{
	pmd_t __pmd;
	int i;
	unsigned long addr = start;
	struct page *page = pmd_page(*pmd);
	pte_t *pgtable = pte_alloc_one_kernel(&init_mm);

	if (!pgtable)
		return -ENOMEM;

	pmd_populate_kernel(&init_mm, &__pmd, pgtable);

	for (i = 0; i < PMD_SIZE / PAGE_SIZE; i++, addr += PAGE_SIZE) {
		pte_t entry, *pte;
		pgprot_t pgprot = PAGE_KERNEL;

		entry = mk_pte(page + i, pgprot);
		pte = pte_offset_kernel(&__pmd, addr);
		set_pte_at(&init_mm, addr, pte, entry);
	}

	spin_lock(&init_mm.page_table_lock);
	if (likely(pmd_leaf(*pmd))) {
		/* Make pte visible before pmd. See comment in pmd_install(). */
		smp_wmb();
		pmd_populate_kernel(&init_mm, pmd, pgtable);
		flush_tlb_kernel_range(start, start + PMD_SIZE);
	} else {
		pte_free_kernel(&init_mm, pgtable);
	}
	spin_unlock(&init_mm.page_table_lock);

	return 0;
}

static int split_vmemmap_huge_pmd(pmd_t *pmd, unsigned long start)
{
	int leaf;

	spin_lock(&init_mm.page_table_lock);
	leaf = pmd_leaf(*pmd);
	spin_unlock(&init_mm.page_table_lock);

	if (!leaf)
		return 0;

	return __split_vmemmap_huge_pmd(pmd, start);
}

static void vmemmap_pte_range(pmd_t *pmd, unsigned long addr,
			      unsigned long end,
			      struct vmemmap_remap_walk *walk)
{
	pte_t *pte = pte_offset_kernel(pmd, addr);

	/*
	 * The reuse_page is found 'first' in table walk before we start
	 * remapping (which is calling @walk->remap_pte).
	 */
	if (!walk->reuse_page) {
		walk->reuse_page = pte_page(*pte);
		/*
		 * Because the reuse address is part of the range that we are
		 * walking, skip the reuse address range.
		 */
		addr += PAGE_SIZE;
		pte++;
		walk->nr_walked++;
	}

	for (; addr != end; addr += PAGE_SIZE, pte++) {
		walk->remap_pte(pte, addr, walk);
		walk->nr_walked++;
	}
}

static int vmemmap_pmd_range(pud_t *pud, unsigned long addr,
			     unsigned long end,
			     struct vmemmap_remap_walk *walk)
{
	pmd_t *pmd;
	unsigned long next;

	pmd = pmd_offset(pud, addr);
	do {
		int ret;

		ret = split_vmemmap_huge_pmd(pmd, addr & PMD_MASK);
		if (ret)
			return ret;

		next = pmd_addr_end(addr, end);
		vmemmap_pte_range(pmd, addr, next, walk);
	} while (pmd++, addr = next, addr != end);

	return 0;
}

static int vmemmap_pud_range(p4d_t *p4d, unsigned long addr,
			     unsigned long end,
			     struct vmemmap_remap_walk *walk)
{
	pud_t *pud;
	unsigned long next;

	pud = pud_offset(p4d, addr);
	do {
		int ret;

		next = pud_addr_end(addr, end);
		ret = vmemmap_pmd_range(pud, addr, next, walk);
		if (ret)
			return ret;
	} while (pud++, addr = next, addr != end);

	return 0;
}

static int vmemmap_p4d_range(pgd_t *pgd, unsigned long addr,
			     unsigned long end,
			     struct vmemmap_remap_walk *walk)
{
	p4d_t *p4d;
	unsigned long next;

	p4d = p4d_offset(pgd, addr);
	do {
		int ret;

		next = p4d_addr_end(addr, end);
		ret = vmemmap_pud_range(p4d, addr, next, walk);
		if (ret)
			return ret;
	} while (p4d++, addr = next, addr != end);

	return 0;
}

static int vmemmap_remap_range(unsigned long start, unsigned long end,
			       struct vmemmap_remap_walk *walk)
{
	unsigned long addr = start;
	unsigned long next;
	pgd_t *pgd;

	VM_BUG_ON(!IS_ALIGNED(start, PAGE_SIZE));
	VM_BUG_ON(!IS_ALIGNED(end, PAGE_SIZE));

	pgd = pgd_offset_k(addr);
	do {
		int ret;

		next = pgd_addr_end(addr, end);
		ret = vmemmap_p4d_range(pgd, addr, next, walk);
		if (ret)
			return ret;
	} while (pgd++, addr = next, addr != end);

	/*
	 * We only change the mapping of the vmemmap virtual address range
	 * [@start + PAGE_SIZE, end), so we only need to flush the TLB which
	 * belongs to the range.
	 */
	flush_tlb_kernel_range(start + PAGE_SIZE, end);

	return 0;
}

/*
 * Free a vmemmap page. A vmemmap page can be allocated from the memblock
 * allocator or buddy allocator. If the PG_reserved flag is set, it means
 * that it allocated from the memblock allocator, just free it via the
 * free_bootmem_page(). Otherwise, use __free_page().
 */
static inline void free_vmemmap_page(struct page *page)
{
	if (PageReserved(page))
		free_bootmem_page(page);
	else
		__free_page(page);
}

/* Free a list of the vmemmap pages */
static void free_vmemmap_page_list(struct list_head *list)
{
	struct page *page, *next;

	list_for_each_entry_safe(page, next, list, lru) {
		list_del(&page->lru);
		free_vmemmap_page(page);
	}
}

static void vmemmap_remap_pte(pte_t *pte, unsigned long addr,
			      struct vmemmap_remap_walk *walk)
{
	/*
	 * Remap the tail pages as read-only to catch illegal write operation
	 * to the tail pages.
	 */
	pgprot_t pgprot = PAGE_KERNEL_RO;
	pte_t entry = mk_pte(walk->reuse_page, pgprot);
	struct page *page = pte_page(*pte);

	list_add_tail(&page->lru, walk->vmemmap_pages);
	set_pte_at(&init_mm, addr, pte, entry);
}

/*
 * How many struct page structs need to be reset. When we reuse the head
 * struct page, the special metadata (e.g. page->flags or page->mapping)
 * cannot copy to the tail struct page structs. The invalid value will be
 * checked in the free_tail_pages_check(). In order to avoid the message
 * of "corrupted mapping in tail page". We need to reset at least 3 (one
 * head struct page struct and two tail struct page structs) struct page
 * structs.
 */
#define NR_RESET_STRUCT_PAGE		3

static inline void reset_struct_pages(struct page *start)
{
	int i;
	struct page *from = start + NR_RESET_STRUCT_PAGE;

	for (i = 0; i < NR_RESET_STRUCT_PAGE; i++)
		memcpy(start + i, from, sizeof(*from));
}

static void vmemmap_restore_pte(pte_t *pte, unsigned long addr,
				struct vmemmap_remap_walk *walk)
{
	pgprot_t pgprot = PAGE_KERNEL;
	struct page *page;
	void *to;

	BUG_ON(pte_page(*pte) != walk->reuse_page);

	page = list_first_entry(walk->vmemmap_pages, struct page, lru);
	list_del(&page->lru);
	to = page_to_virt(page);
	copy_page(to, (void *)walk->reuse_addr);
	reset_struct_pages(to);

	set_pte_at(&init_mm, addr, pte, mk_pte(page, pgprot));
}

/**
 * vmemmap_remap_free - remap the vmemmap virtual address range [@start, @end)
 *			to the page which @reuse is mapped to, then free vmemmap
 *			which the range are mapped to.
 * @start:	start address of the vmemmap virtual address range that we want
 *		to remap.
 * @end:	end address of the vmemmap virtual address range that we want to
 *		remap.
 * @reuse:	reuse address.
 *
 * Return: %0 on success, negative error code otherwise.
 */
int vmemmap_remap_free(unsigned long start, unsigned long end,
		       unsigned long reuse)
{
	int ret;
	LIST_HEAD(vmemmap_pages);
	struct vmemmap_remap_walk walk = {
		.remap_pte	= vmemmap_remap_pte,
		.reuse_addr	= reuse,
		.vmemmap_pages	= &vmemmap_pages,
	};

	/*
	 * In order to make remapping routine most efficient for the huge pages,
	 * the routine of vmemmap page table walking has the following rules
	 * (see more details from the vmemmap_pte_range()):
	 *
	 * - The range [@start, @end) and the range [@reuse, @reuse + PAGE_SIZE)
	 *   should be continuous.
	 * - The @reuse address is part of the range [@reuse, @end) that we are
	 *   walking which is passed to vmemmap_remap_range().
	 * - The @reuse address is the first in the complete range.
	 *
	 * So we need to make sure that @start and @reuse meet the above rules.
	 */
	BUG_ON(start - reuse != PAGE_SIZE);

	mmap_read_lock(&init_mm);
	ret = vmemmap_remap_range(reuse, end, &walk);
	if (ret && walk.nr_walked) {
		end = reuse + walk.nr_walked * PAGE_SIZE;
		/*
		 * vmemmap_pages contains pages from the previous
		 * vmemmap_remap_range call which failed.  These
		 * are pages which were removed from the vmemmap.
		 * They will be restored in the following call.
		 */
		walk = (struct vmemmap_remap_walk) {
			.remap_pte	= vmemmap_restore_pte,
			.reuse_addr	= reuse,
			.vmemmap_pages	= &vmemmap_pages,
		};

		vmemmap_remap_range(reuse, end, &walk);
	}
	mmap_read_unlock(&init_mm);

	free_vmemmap_page_list(&vmemmap_pages);

	return ret;
}

static int alloc_vmemmap_page_list(unsigned long start, unsigned long end,
				   gfp_t gfp_mask, struct list_head *list)
{
	unsigned long nr_pages = (end - start) >> PAGE_SHIFT;
	int nid = page_to_nid((struct page *)start);
	struct page *page, *next;

	while (nr_pages--) {
		page = alloc_pages_node(nid, gfp_mask, 0);
		if (!page)
			goto out;
		list_add_tail(&page->lru, list);
	}

	return 0;
out:
	list_for_each_entry_safe(page, next, list, lru)
		__free_pages(page, 0);
	return -ENOMEM;
}

/**
 * vmemmap_remap_alloc - remap the vmemmap virtual address range [@start, end)
 *			 to the page which is from the @vmemmap_pages
 *			 respectively.
 * @start:	start address of the vmemmap virtual address range that we want
 *		to remap.
 * @end:	end address of the vmemmap virtual address range that we want to
 *		remap.
 * @reuse:	reuse address.
 * @gfp_mask:	GFP flag for allocating vmemmap pages.
 *
 * Return: %0 on success, negative error code otherwise.
 */
int vmemmap_remap_alloc(unsigned long start, unsigned long end,
			unsigned long reuse, gfp_t gfp_mask)
{
	LIST_HEAD(vmemmap_pages);
	struct vmemmap_remap_walk walk = {
		.remap_pte	= vmemmap_restore_pte,
		.reuse_addr	= reuse,
		.vmemmap_pages	= &vmemmap_pages,
	};

	/* See the comment in the vmemmap_remap_free(). */
	BUG_ON(start - reuse != PAGE_SIZE);

	if (alloc_vmemmap_page_list(start, end, gfp_mask, &vmemmap_pages))
		return -ENOMEM;

	mmap_read_lock(&init_mm);
	vmemmap_remap_range(reuse, end, &walk);
	mmap_read_unlock(&init_mm);

	return 0;
}
#endif /* CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP */

/*
 * 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.
 * Uses the main allocators if they are available, else bootmem.
 */

static void * __ref __earlyonly_bootmem_alloc(int node,
				unsigned long size,
				unsigned long align,
				unsigned long goal)
{
	return memblock_alloc_try_nid_raw(size, align, goal,
					       MEMBLOCK_ALLOC_ACCESSIBLE, node);
}

void * __meminit vmemmap_alloc_block(unsigned long size, int node)
{
	/* If the main allocator is up use that, fallback to bootmem. */
	if (slab_is_available()) {
		gfp_t gfp_mask = GFP_KERNEL|__GFP_RETRY_MAYFAIL|__GFP_NOWARN;
		int order = get_order(size);
		static bool warned;
		struct page *page;

		page = alloc_pages_node(node, gfp_mask, order);
		if (page)
			return page_address(page);

		if (!warned) {
			warn_alloc(gfp_mask & ~__GFP_NOWARN, NULL,
				   "vmemmap alloc failure: order:%u", order);
			warned = true;
		}
		return NULL;
	} else
		return __earlyonly_bootmem_alloc(node, size, size,
				__pa(MAX_DMA_ADDRESS));
}

static void * __meminit altmap_alloc_block_buf(unsigned long size,
					       struct vmem_altmap *altmap);

/* need to make sure size is all the same during early stage */
void * __meminit vmemmap_alloc_block_buf(unsigned long size, int node,
					 struct vmem_altmap *altmap)
{
	void *ptr;

	if (altmap)
		return altmap_alloc_block_buf(size, altmap);

	ptr = sparse_buffer_alloc(size);
	if (!ptr)
		ptr = vmemmap_alloc_block(size, node);
	return ptr;
}

static unsigned long __meminit vmem_altmap_next_pfn(struct vmem_altmap *altmap)
{
	return altmap->base_pfn + altmap->reserve + altmap->alloc
		+ altmap->align;
}

static unsigned long __meminit vmem_altmap_nr_free(struct vmem_altmap *altmap)
{
	unsigned long allocated = altmap->alloc + altmap->align;

	if (altmap->free > allocated)
		return altmap->free - allocated;
	return 0;
}

static void * __meminit altmap_alloc_block_buf(unsigned long size,
					       struct vmem_altmap *altmap)
{
	unsigned long pfn, nr_pfns, nr_align;

	if (size & ~PAGE_MASK) {
		pr_warn_once("%s: allocations must be multiple of PAGE_SIZE (%ld)\n",
				__func__, size);
		return NULL;
	}

	pfn = vmem_altmap_next_pfn(altmap);
	nr_pfns = size >> PAGE_SHIFT;
	nr_align = 1UL << find_first_bit(&nr_pfns, BITS_PER_LONG);
	nr_align = ALIGN(pfn, nr_align) - pfn;
	if (nr_pfns + nr_align > vmem_altmap_nr_free(altmap))
		return NULL;

	altmap->alloc += nr_pfns;
	altmap->align += nr_align;
	pfn += nr_align;

	pr_debug("%s: pfn: %#lx alloc: %ld align: %ld nr: %#lx\n",
			__func__, pfn, altmap->alloc, altmap->align, nr_pfns);
	return __va(__pfn_to_phys(pfn));
}

void __meminit vmemmap_verify(pte_t *pte, int node,
				unsigned long start, unsigned long end)
{
	unsigned long pfn = pte_pfn(*pte);
	int actual_node = early_pfn_to_nid(pfn);

	if (node_distance(actual_node, node) > LOCAL_DISTANCE)
		pr_warn("[%lx-%lx] potential offnode page_structs\n",
			start, end - 1);
}

pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node,
				       struct vmem_altmap *altmap)
{
	pte_t *pte = pte_offset_kernel(pmd, addr);
	if (pte_none(*pte)) {
		pte_t entry;
		void *p;

		p = vmemmap_alloc_block_buf(PAGE_SIZE, node, altmap);
		if (!p)
			return NULL;
		entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL);
		set_pte_at(&init_mm, addr, pte, entry);
	}
	return pte;
}

static void * __meminit vmemmap_alloc_block_zero(unsigned long size, int node)
{
	void *p = vmemmap_alloc_block(size, node);

	if (!p)
		return NULL;
	memset(p, 0, size);

	return p;
}

pmd_t * __meminit vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node)
{
	pmd_t *pmd = pmd_offset(pud, addr);
	if (pmd_none(*pmd)) {
		void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
		if (!p)
			return NULL;
		pmd_populate_kernel(&init_mm, pmd, p);
	}
	return pmd;
}

pud_t * __meminit vmemmap_pud_populate(p4d_t *p4d, unsigned long addr, int node)
{
	pud_t *pud = pud_offset(p4d, addr);
	if (pud_none(*pud)) {
		void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
		if (!p)
			return NULL;
		pud_populate(&init_mm, pud, p);
	}
	return pud;
}

p4d_t * __meminit vmemmap_p4d_populate(pgd_t *pgd, unsigned long addr, int node)
{
	p4d_t *p4d = p4d_offset(pgd, addr);
	if (p4d_none(*p4d)) {
		void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
		if (!p)
			return NULL;
		p4d_populate(&init_mm, p4d, p);
	}
	return p4d;
}

pgd_t * __meminit vmemmap_pgd_populate(unsigned long addr, int node)
{
	pgd_t *pgd = pgd_offset_k(addr);
	if (pgd_none(*pgd)) {
		void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
		if (!p)
			return NULL;
		pgd_populate(&init_mm, pgd, p);
	}
	return pgd;
}

int __meminit vmemmap_populate_basepages(unsigned long start, unsigned long end,
					 int node, struct vmem_altmap *altmap)
{
	unsigned long addr = start;
	pgd_t *pgd;
	p4d_t *p4d;
	pud_t *pud;
	pmd_t *pmd;
	pte_t *pte;

	for (; addr < end; addr += PAGE_SIZE) {
		pgd = vmemmap_pgd_populate(addr, node);
		if (!pgd)
			return -ENOMEM;
		p4d = vmemmap_p4d_populate(pgd, addr, node);
		if (!p4d)
			return -ENOMEM;
		pud = vmemmap_pud_populate(p4d, addr, node);
		if (!pud)
			return -ENOMEM;
		pmd = vmemmap_pmd_populate(pud, addr, node);
		if (!pmd)
			return -ENOMEM;
		pte = vmemmap_pte_populate(pmd, addr, node, altmap);
		if (!pte)
			return -ENOMEM;
		vmemmap_verify(pte, node, addr, addr + PAGE_SIZE);
	}

	return 0;
}

struct page * __meminit __populate_section_memmap(unsigned long pfn,
		unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
{
	unsigned long start = (unsigned long) pfn_to_page(pfn);
	unsigned long end = start + nr_pages * sizeof(struct page);

	if (WARN_ON_ONCE(!IS_ALIGNED(pfn, PAGES_PER_SUBSECTION) ||
		!IS_ALIGNED(nr_pages, PAGES_PER_SUBSECTION)))
		return NULL;

	if (vmemmap_populate(start, end, nid, altmap))
		return NULL;

	return pfn_to_page(pfn);
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
8f6aac41 CL	2	/*
	3	* Virtual Memory Map support
	4	*
cde53535	5	* (C) 2007 sgi. Christoph Lameter.
8f6aac41 CL	6	*
	7	* Virtual memory maps allow VM primitives pfn_to_page, page_to_pfn,
	8	* virt_to_page, page_address() to be implemented as a base offset
	9	* calculation without memory access.
	10	*
	11	* However, virtual mappings need a page table and TLBs. Many Linux
	12	* architectures already map their physical space using 1-1 mappings
b595076a	13	* via TLBs. For those arches the virtual memory map is essentially
8f6aac41 CL	14	* for free if we use the same page size as the 1-1 mappings. In that
	15	* case the overhead consists of a few additional pages that are
	16	* allocated to create a view of memory for vmemmap.
	17	*
29c71111 AW	18	* The architecture is expected to provide a vmemmap_populate() function
29c71111 AW	19	* to instantiate the mapping.
8f6aac41 CL	20	*/
	21	#include <linux/mm.h>
	22	#include <linux/mmzone.h>
97ad1087	23	#include <linux/memblock.h>
4b94ffdc	24	#include <linux/memremap.h>
8f6aac41	25	#include <linux/highmem.h>
5a0e3ad6	26	#include <linux/slab.h>
8f6aac41 CL	27	#include <linux/spinlock.h>
8f6aac41 CL	28	#include <linux/vmalloc.h>
8bca44bb	29	#include <linux/sched.h>
f41f2ed4 MS	30	#include <linux/pgtable.h>
	31	#include <linux/bootmem_info.h>
	32
8f6aac41 CL	33	#include <asm/dma.h>
8f6aac41 CL	34	#include <asm/pgalloc.h>
f41f2ed4 MS	35	#include <asm/tlbflush.h>
f41f2ed4 MS	36
47010c04	37	#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
f41f2ed4 MS	38	/**
	39	* struct vmemmap_remap_walk - walk vmemmap page table
	40	*
	41	* @remap_pte: called for each lowest-level entry (PTE).
3bc2b6a7	42	* @nr_walked: the number of walked pte.
f41f2ed4 MS	43	* @reuse_page: the page which is reused for the tail vmemmap pages.
f41f2ed4 MS	44	* @reuse_addr: the virtual address of the @reuse_page page.
ad2fa371 MS	45	* @vmemmap_pages: the list head of the vmemmap pages that can be freed
ad2fa371 MS	46	* or is mapped from.
f41f2ed4 MS	47	*/
	48	struct vmemmap_remap_walk {
	49	void (remap_pte)(pte_t pte, unsigned long addr,
	50	struct vmemmap_remap_walk *walk);
3bc2b6a7	51	unsigned long nr_walked;
f41f2ed4 MS	52	struct page *reuse_page;
	53	unsigned long reuse_addr;
	54	struct list_head *vmemmap_pages;
	55	};
	56
d8d55f56	57	static int __split_vmemmap_huge_pmd(pmd_t *pmd, unsigned long start)
3bc2b6a7 MS	58	{
	59	pmd_t __pmd;
	60	int i;
	61	unsigned long addr = start;
	62	struct page page = pmd_page(pmd);
	63	pte_t *pgtable = pte_alloc_one_kernel(&init_mm);
	64
	65	if (!pgtable)
	66	return -ENOMEM;
	67
	68	pmd_populate_kernel(&init_mm, &__pmd, pgtable);
	69
	70	for (i = 0; i < PMD_SIZE / PAGE_SIZE; i++, addr += PAGE_SIZE) {
	71	pte_t entry, *pte;
	72	pgprot_t pgprot = PAGE_KERNEL;
	73
	74	entry = mk_pte(page + i, pgprot);
	75	pte = pte_offset_kernel(&__pmd, addr);
	76	set_pte_at(&init_mm, addr, pte, entry);
	77	}
	78
d8d55f56 MS	79	spin_lock(&init_mm.page_table_lock);
	80	if (likely(pmd_leaf(*pmd))) {
	81	/* Make pte visible before pmd. See comment in pmd_install(). */
	82	smp_wmb();
	83	pmd_populate_kernel(&init_mm, pmd, pgtable);
	84	flush_tlb_kernel_range(start, start + PMD_SIZE);
	85	} else {
	86	pte_free_kernel(&init_mm, pgtable);
	87	}
	88	spin_unlock(&init_mm.page_table_lock);
3bc2b6a7 MS	89
	90	return 0;
	91	}
	92
d8d55f56 MS	93	static int split_vmemmap_huge_pmd(pmd_t *pmd, unsigned long start)
	94	{
	95	int leaf;
	96
	97	spin_lock(&init_mm.page_table_lock);
	98	leaf = pmd_leaf(*pmd);
	99	spin_unlock(&init_mm.page_table_lock);
	100
	101	if (!leaf)
	102	return 0;
	103
	104	return __split_vmemmap_huge_pmd(pmd, start);
	105	}
	106
f41f2ed4 MS	107	static void vmemmap_pte_range(pmd_t *pmd, unsigned long addr,
	108	unsigned long end,
	109	struct vmemmap_remap_walk *walk)
	110	{
	111	pte_t *pte = pte_offset_kernel(pmd, addr);
	112
	113	/*
	114	* The reuse_page is found 'first' in table walk before we start
	115	* remapping (which is calling @walk->remap_pte).
	116	*/
	117	if (!walk->reuse_page) {
	118	walk->reuse_page = pte_page(*pte);
	119	/*
	120	* Because the reuse address is part of the range that we are
	121	* walking, skip the reuse address range.
	122	*/
	123	addr += PAGE_SIZE;
	124	pte++;
3bc2b6a7	125	walk->nr_walked++;
f41f2ed4 MS	126	}
f41f2ed4 MS	127
3bc2b6a7	128	for (; addr != end; addr += PAGE_SIZE, pte++) {
f41f2ed4	129	walk->remap_pte(pte, addr, walk);
3bc2b6a7 MS	130	walk->nr_walked++;
3bc2b6a7 MS	131	}
f41f2ed4 MS	132	}
f41f2ed4 MS	133
3bc2b6a7 MS	134	static int vmemmap_pmd_range(pud_t *pud, unsigned long addr,
	135	unsigned long end,
	136	struct vmemmap_remap_walk *walk)
f41f2ed4 MS	137	{
	138	pmd_t *pmd;
	139	unsigned long next;
	140
	141	pmd = pmd_offset(pud, addr);
	142	do {
d8d55f56 MS	143	int ret;
	144
	145	ret = split_vmemmap_huge_pmd(pmd, addr & PMD_MASK);
	146	if (ret)
	147	return ret;
f41f2ed4 MS	148
	149	next = pmd_addr_end(addr, end);
	150	vmemmap_pte_range(pmd, addr, next, walk);
	151	} while (pmd++, addr = next, addr != end);
3bc2b6a7 MS	152
3bc2b6a7 MS	153	return 0;
f41f2ed4 MS	154	}
f41f2ed4 MS	155
3bc2b6a7 MS	156	static int vmemmap_pud_range(p4d_t *p4d, unsigned long addr,
	157	unsigned long end,
	158	struct vmemmap_remap_walk *walk)
f41f2ed4 MS	159	{
	160	pud_t *pud;
	161	unsigned long next;
	162
	163	pud = pud_offset(p4d, addr);
	164	do {
3bc2b6a7 MS	165	int ret;
3bc2b6a7 MS	166
f41f2ed4	167	next = pud_addr_end(addr, end);
3bc2b6a7 MS	168	ret = vmemmap_pmd_range(pud, addr, next, walk);
	169	if (ret)
	170	return ret;
f41f2ed4	171	} while (pud++, addr = next, addr != end);
3bc2b6a7 MS	172
3bc2b6a7 MS	173	return 0;
f41f2ed4 MS	174	}
f41f2ed4 MS	175
3bc2b6a7 MS	176	static int vmemmap_p4d_range(pgd_t *pgd, unsigned long addr,
	177	unsigned long end,
	178	struct vmemmap_remap_walk *walk)
f41f2ed4 MS	179	{
	180	p4d_t *p4d;
	181	unsigned long next;
	182
	183	p4d = p4d_offset(pgd, addr);
	184	do {
3bc2b6a7 MS	185	int ret;
3bc2b6a7 MS	186
f41f2ed4	187	next = p4d_addr_end(addr, end);
3bc2b6a7 MS	188	ret = vmemmap_pud_range(p4d, addr, next, walk);
	189	if (ret)
	190	return ret;
f41f2ed4	191	} while (p4d++, addr = next, addr != end);
3bc2b6a7 MS	192
3bc2b6a7 MS	193	return 0;
f41f2ed4 MS	194	}
f41f2ed4 MS	195
3bc2b6a7 MS	196	static int vmemmap_remap_range(unsigned long start, unsigned long end,
3bc2b6a7 MS	197	struct vmemmap_remap_walk *walk)
f41f2ed4 MS	198	{
	199	unsigned long addr = start;
	200	unsigned long next;
	201	pgd_t *pgd;
	202
	203	VM_BUG_ON(!IS_ALIGNED(start, PAGE_SIZE));
	204	VM_BUG_ON(!IS_ALIGNED(end, PAGE_SIZE));
	205
	206	pgd = pgd_offset_k(addr);
	207	do {
3bc2b6a7 MS	208	int ret;
3bc2b6a7 MS	209
f41f2ed4	210	next = pgd_addr_end(addr, end);
3bc2b6a7 MS	211	ret = vmemmap_p4d_range(pgd, addr, next, walk);
	212	if (ret)
	213	return ret;
f41f2ed4 MS	214	} while (pgd++, addr = next, addr != end);
	215
	216	/*
	217	* We only change the mapping of the vmemmap virtual address range
	218	* [@start + PAGE_SIZE, end), so we only need to flush the TLB which
	219	* belongs to the range.
	220	*/
	221	flush_tlb_kernel_range(start + PAGE_SIZE, end);
3bc2b6a7 MS	222
3bc2b6a7 MS	223	return 0;
f41f2ed4 MS	224	}
	225
	226	/*
	227	* Free a vmemmap page. A vmemmap page can be allocated from the memblock
	228	* allocator or buddy allocator. If the PG_reserved flag is set, it means
	229	* that it allocated from the memblock allocator, just free it via the
	230	* free_bootmem_page(). Otherwise, use __free_page().
	231	*/
	232	static inline void free_vmemmap_page(struct page *page)
	233	{
	234	if (PageReserved(page))
	235	free_bootmem_page(page);
	236	else
	237	__free_page(page);
	238	}
	239
	240	/* Free a list of the vmemmap pages */
	241	static void free_vmemmap_page_list(struct list_head *list)
	242	{
	243	struct page page, next;
	244
	245	list_for_each_entry_safe(page, next, list, lru) {
	246	list_del(&page->lru);
	247	free_vmemmap_page(page);
	248	}
	249	}
	250
	251	static void vmemmap_remap_pte(pte_t *pte, unsigned long addr,
	252	struct vmemmap_remap_walk *walk)
	253	{
	254	/*
	255	* Remap the tail pages as read-only to catch illegal write operation
	256	* to the tail pages.
	257	*/
	258	pgprot_t pgprot = PAGE_KERNEL_RO;
	259	pte_t entry = mk_pte(walk->reuse_page, pgprot);
	260	struct page page = pte_page(pte);
	261
3bc2b6a7	262	list_add_tail(&page->lru, walk->vmemmap_pages);
f41f2ed4 MS	263	set_pte_at(&init_mm, addr, pte, entry);
	264	}
	265
e7d32485 MS	266	/*
	267	* How many struct page structs need to be reset. When we reuse the head
	268	* struct page, the special metadata (e.g. page->flags or page->mapping)
	269	* cannot copy to the tail struct page structs. The invalid value will be
	270	* checked in the free_tail_pages_check(). In order to avoid the message
	271	* of "corrupted mapping in tail page". We need to reset at least 3 (one
	272	* head struct page struct and two tail struct page structs) struct page
	273	* structs.
	274	*/
	275	#define NR_RESET_STRUCT_PAGE 3
	276
	277	static inline void reset_struct_pages(struct page *start)
	278	{
	279	int i;
	280	struct page *from = start + NR_RESET_STRUCT_PAGE;
	281
	282	for (i = 0; i < NR_RESET_STRUCT_PAGE; i++)
	283	memcpy(start + i, from, sizeof(*from));
	284	}
	285
3bc2b6a7 MS	286	static void vmemmap_restore_pte(pte_t *pte, unsigned long addr,
	287	struct vmemmap_remap_walk *walk)
	288	{
	289	pgprot_t pgprot = PAGE_KERNEL;
	290	struct page *page;
	291	void *to;
	292
	293	BUG_ON(pte_page(*pte) != walk->reuse_page);
	294
	295	page = list_first_entry(walk->vmemmap_pages, struct page, lru);
	296	list_del(&page->lru);
	297	to = page_to_virt(page);
	298	copy_page(to, (void *)walk->reuse_addr);
e7d32485	299	reset_struct_pages(to);
3bc2b6a7 MS	300
	301	set_pte_at(&init_mm, addr, pte, mk_pte(page, pgprot));
	302	}
	303
f41f2ed4 MS	304	/**
	305	* vmemmap_remap_free - remap the vmemmap virtual address range [@start, @end)
	306	* to the page which @reuse is mapped to, then free vmemmap
	307	* which the range are mapped to.
	308	* @start: start address of the vmemmap virtual address range that we want
	309	* to remap.
	310	* @end: end address of the vmemmap virtual address range that we want to
	311	* remap.
	312	* @reuse: reuse address.
	313	*
3bc2b6a7	314	* Return: %0 on success, negative error code otherwise.
f41f2ed4	315	*/
3bc2b6a7 MS	316	int vmemmap_remap_free(unsigned long start, unsigned long end,
3bc2b6a7 MS	317	unsigned long reuse)
f41f2ed4	318	{
3bc2b6a7	319	int ret;
f41f2ed4 MS	320	LIST_HEAD(vmemmap_pages);
	321	struct vmemmap_remap_walk walk = {
	322	.remap_pte = vmemmap_remap_pte,
	323	.reuse_addr = reuse,
	324	.vmemmap_pages = &vmemmap_pages,
	325	};
	326
	327	/*
	328	* In order to make remapping routine most efficient for the huge pages,
	329	* the routine of vmemmap page table walking has the following rules
	330	* (see more details from the vmemmap_pte_range()):
	331	*
	332	* - The range [@start, @end) and the range [@reuse, @reuse + PAGE_SIZE)
	333	* should be continuous.
	334	* - The @reuse address is part of the range [@reuse, @end) that we are
	335	* walking which is passed to vmemmap_remap_range().
	336	* - The @reuse address is the first in the complete range.
	337	*
	338	* So we need to make sure that @start and @reuse meet the above rules.
	339	*/
	340	BUG_ON(start - reuse != PAGE_SIZE);
	341
d8d55f56	342	mmap_read_lock(&init_mm);
3bc2b6a7	343	ret = vmemmap_remap_range(reuse, end, &walk);
3bc2b6a7 MS	344	if (ret && walk.nr_walked) {
	345	end = reuse + walk.nr_walked * PAGE_SIZE;
	346	/*
	347	* vmemmap_pages contains pages from the previous
	348	* vmemmap_remap_range call which failed. These
	349	* are pages which were removed from the vmemmap.
	350	* They will be restored in the following call.
	351	*/
	352	walk = (struct vmemmap_remap_walk) {
	353	.remap_pte = vmemmap_restore_pte,
	354	.reuse_addr = reuse,
	355	.vmemmap_pages = &vmemmap_pages,
	356	};
ad2fa371	357
3bc2b6a7 MS	358	vmemmap_remap_range(reuse, end, &walk);
	359	}
	360	mmap_read_unlock(&init_mm);
ad2fa371	361
3bc2b6a7	362	free_vmemmap_page_list(&vmemmap_pages);
ad2fa371	363
3bc2b6a7	364	return ret;
ad2fa371 MS	365	}
	366
	367	static int alloc_vmemmap_page_list(unsigned long start, unsigned long end,
	368	gfp_t gfp_mask, struct list_head *list)
	369	{
	370	unsigned long nr_pages = (end - start) >> PAGE_SHIFT;
	371	int nid = page_to_nid((struct page *)start);
	372	struct page page, next;
	373
	374	while (nr_pages--) {
	375	page = alloc_pages_node(nid, gfp_mask, 0);
	376	if (!page)
	377	goto out;
	378	list_add_tail(&page->lru, list);
	379	}
	380
	381	return 0;
	382	out:
	383	list_for_each_entry_safe(page, next, list, lru)
	384	__free_pages(page, 0);
	385	return -ENOMEM;
	386	}
	387
	388	/**
	389	* vmemmap_remap_alloc - remap the vmemmap virtual address range [@start, end)
	390	* to the page which is from the @vmemmap_pages
	391	* respectively.
	392	* @start: start address of the vmemmap virtual address range that we want
	393	* to remap.
	394	* @end: end address of the vmemmap virtual address range that we want to
	395	* remap.
	396	* @reuse: reuse address.
	397	* @gfp_mask: GFP flag for allocating vmemmap pages.
3bc2b6a7 MS	398	*
3bc2b6a7 MS	399	* Return: %0 on success, negative error code otherwise.
ad2fa371 MS	400	*/
	401	int vmemmap_remap_alloc(unsigned long start, unsigned long end,
	402	unsigned long reuse, gfp_t gfp_mask)
	403	{
	404	LIST_HEAD(vmemmap_pages);
	405	struct vmemmap_remap_walk walk = {
	406	.remap_pte = vmemmap_restore_pte,
	407	.reuse_addr = reuse,
	408	.vmemmap_pages = &vmemmap_pages,
	409	};
	410
	411	/* See the comment in the vmemmap_remap_free(). */
	412	BUG_ON(start - reuse != PAGE_SIZE);
	413
ad2fa371 MS	414	if (alloc_vmemmap_page_list(start, end, gfp_mask, &vmemmap_pages))
	415	return -ENOMEM;
	416
3bc2b6a7	417	mmap_read_lock(&init_mm);
ad2fa371	418	vmemmap_remap_range(reuse, end, &walk);
3bc2b6a7	419	mmap_read_unlock(&init_mm);
ad2fa371 MS	420
	421	return 0;
	422	}
47010c04	423	#endif /* CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP */
ad2fa371	424
8f6aac41 CL	425	/*
	426	* Allocate a block of memory to be used to back the virtual memory map
	427	* or to back the page tables that are used to create the mapping.
	428	* Uses the main allocators if they are available, else bootmem.
	429	*/
e0dc3a53	430
bd721ea7	431	static void * __ref __earlyonly_bootmem_alloc(int node,
e0dc3a53 KH	432	unsigned long size,
	433	unsigned long align,
	434	unsigned long goal)
	435	{
eb31d559	436	return memblock_alloc_try_nid_raw(size, align, goal,
97ad1087	437	MEMBLOCK_ALLOC_ACCESSIBLE, node);
e0dc3a53 KH	438	}
e0dc3a53 KH	439
8f6aac41 CL	440	void * __meminit vmemmap_alloc_block(unsigned long size, int node)
	441	{
	442	/* If the main allocator is up use that, fallback to bootmem. */
	443	if (slab_is_available()) {
fcdaf842 MH	444	gfp_t gfp_mask = GFP_KERNEL\|__GFP_RETRY_MAYFAIL\|__GFP_NOWARN;
	445	int order = get_order(size);
	446	static bool warned;
f52407ce SL	447	struct page *page;
f52407ce SL	448
fcdaf842	449	page = alloc_pages_node(node, gfp_mask, order);
8f6aac41 CL	450	if (page)
8f6aac41 CL	451	return page_address(page);
fcdaf842 MH	452
	453	if (!warned) {
	454	warn_alloc(gfp_mask & ~__GFP_NOWARN, NULL,
	455	"vmemmap alloc failure: order:%u", order);
	456	warned = true;
	457	}
8f6aac41 CL	458	return NULL;
8f6aac41 CL	459	} else
e0dc3a53	460	return __earlyonly_bootmem_alloc(node, size, size,
8f6aac41 CL	461	__pa(MAX_DMA_ADDRESS));
	462	}
	463
56993b4e AK	464	static void * __meminit altmap_alloc_block_buf(unsigned long size,
	465	struct vmem_altmap *altmap);
	466
9bdac914	467	/* need to make sure size is all the same during early stage */
56993b4e AK	468	void * __meminit vmemmap_alloc_block_buf(unsigned long size, int node,
56993b4e AK	469	struct vmem_altmap *altmap)
9bdac914	470	{
56993b4e AK	471	void *ptr;
	472
	473	if (altmap)
	474	return altmap_alloc_block_buf(size, altmap);
9bdac914	475
56993b4e	476	ptr = sparse_buffer_alloc(size);
35fd1eb1 PT	477	if (!ptr)
35fd1eb1 PT	478	ptr = vmemmap_alloc_block(size, node);
9bdac914 YL	479	return ptr;
	480	}
	481
4b94ffdc DW	482	static unsigned long __meminit vmem_altmap_next_pfn(struct vmem_altmap *altmap)
	483	{
	484	return altmap->base_pfn + altmap->reserve + altmap->alloc
	485	+ altmap->align;
	486	}
	487
	488	static unsigned long __meminit vmem_altmap_nr_free(struct vmem_altmap *altmap)
	489	{
	490	unsigned long allocated = altmap->alloc + altmap->align;
	491
	492	if (altmap->free > allocated)
	493	return altmap->free - allocated;
	494	return 0;
	495	}
	496
56993b4e AK	497	static void * __meminit altmap_alloc_block_buf(unsigned long size,
56993b4e AK	498	struct vmem_altmap *altmap)
4b94ffdc	499	{
eb804533	500	unsigned long pfn, nr_pfns, nr_align;
4b94ffdc DW	501
	502	if (size & ~PAGE_MASK) {
	503	pr_warn_once("%s: allocations must be multiple of PAGE_SIZE (%ld)\n",
	504	__func__, size);
	505	return NULL;
	506	}
	507
eb804533	508	pfn = vmem_altmap_next_pfn(altmap);
4b94ffdc	509	nr_pfns = size >> PAGE_SHIFT;
eb804533 CH	510	nr_align = 1UL << find_first_bit(&nr_pfns, BITS_PER_LONG);
	511	nr_align = ALIGN(pfn, nr_align) - pfn;
	512	if (nr_pfns + nr_align > vmem_altmap_nr_free(altmap))
	513	return NULL;
	514
	515	altmap->alloc += nr_pfns;
	516	altmap->align += nr_align;
	517	pfn += nr_align;
	518
4b94ffdc DW	519	pr_debug("%s: pfn: %#lx alloc: %ld align: %ld nr: %#lx\n",
4b94ffdc DW	520	__func__, pfn, altmap->alloc, altmap->align, nr_pfns);
eb804533	521	return __va(__pfn_to_phys(pfn));
4b94ffdc DW	522	}
4b94ffdc DW	523
8f6aac41 CL	524	void __meminit vmemmap_verify(pte_t *pte, int node,
	525	unsigned long start, unsigned long end)
	526	{
	527	unsigned long pfn = pte_pfn(*pte);
	528	int actual_node = early_pfn_to_nid(pfn);
	529
b41ad14c	530	if (node_distance(actual_node, node) > LOCAL_DISTANCE)
1170532b JP	531	pr_warn("[%lx-%lx] potential offnode page_structs\n",
1170532b JP	532	start, end - 1);
8f6aac41 CL	533	}
8f6aac41 CL	534
1d9cfee7 AK	535	pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node,
1d9cfee7 AK	536	struct vmem_altmap *altmap)
8f6aac41	537	{
29c71111 AW	538	pte_t *pte = pte_offset_kernel(pmd, addr);
	539	if (pte_none(*pte)) {
	540	pte_t entry;
1d9cfee7 AK	541	void *p;
1d9cfee7 AK	542
56993b4e	543	p = vmemmap_alloc_block_buf(PAGE_SIZE, node, altmap);
29c71111	544	if (!p)
9dce07f1	545	return NULL;
29c71111 AW	546	entry = pfn_pte(__pa(p) >> PAGE_SHIFT, PAGE_KERNEL);
	547	set_pte_at(&init_mm, addr, pte, entry);
	548	}
	549	return pte;
8f6aac41 CL	550	}
8f6aac41 CL	551
f7f99100 PT	552	static void * __meminit vmemmap_alloc_block_zero(unsigned long size, int node)
	553	{
	554	void *p = vmemmap_alloc_block(size, node);
	555
	556	if (!p)
	557	return NULL;
	558	memset(p, 0, size);
	559
	560	return p;
	561	}
	562
29c71111	563	pmd_t * __meminit vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node)
8f6aac41	564	{
29c71111 AW	565	pmd_t *pmd = pmd_offset(pud, addr);
29c71111 AW	566	if (pmd_none(*pmd)) {
f7f99100	567	void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
29c71111	568	if (!p)
9dce07f1	569	return NULL;
29c71111	570	pmd_populate_kernel(&init_mm, pmd, p);
8f6aac41	571	}
29c71111	572	return pmd;
8f6aac41	573	}
8f6aac41	574
c2febafc	575	pud_t * __meminit vmemmap_pud_populate(p4d_t *p4d, unsigned long addr, int node)
8f6aac41	576	{
c2febafc	577	pud_t *pud = pud_offset(p4d, addr);
29c71111	578	if (pud_none(*pud)) {
f7f99100	579	void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
29c71111	580	if (!p)
9dce07f1	581	return NULL;
29c71111 AW	582	pud_populate(&init_mm, pud, p);
	583	}
	584	return pud;
	585	}
8f6aac41	586
c2febafc KS	587	p4d_t * __meminit vmemmap_p4d_populate(pgd_t *pgd, unsigned long addr, int node)
	588	{
	589	p4d_t *p4d = p4d_offset(pgd, addr);
	590	if (p4d_none(*p4d)) {
f7f99100	591	void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
c2febafc KS	592	if (!p)
	593	return NULL;
	594	p4d_populate(&init_mm, p4d, p);
	595	}
	596	return p4d;
	597	}
	598
29c71111 AW	599	pgd_t * __meminit vmemmap_pgd_populate(unsigned long addr, int node)
	600	{
	601	pgd_t *pgd = pgd_offset_k(addr);
	602	if (pgd_none(*pgd)) {
f7f99100	603	void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node);
29c71111	604	if (!p)
9dce07f1	605	return NULL;
29c71111	606	pgd_populate(&init_mm, pgd, p);
8f6aac41	607	}
29c71111	608	return pgd;
8f6aac41 CL	609	}
8f6aac41 CL	610
1d9cfee7 AK	611	int __meminit vmemmap_populate_basepages(unsigned long start, unsigned long end,
1d9cfee7 AK	612	int node, struct vmem_altmap *altmap)
8f6aac41	613	{
0aad818b	614	unsigned long addr = start;
29c71111	615	pgd_t *pgd;
c2febafc	616	p4d_t *p4d;
29c71111 AW	617	pud_t *pud;
	618	pmd_t *pmd;
	619	pte_t *pte;
8f6aac41	620
29c71111 AW	621	for (; addr < end; addr += PAGE_SIZE) {
	622	pgd = vmemmap_pgd_populate(addr, node);
	623	if (!pgd)
	624	return -ENOMEM;
c2febafc KS	625	p4d = vmemmap_p4d_populate(pgd, addr, node);
	626	if (!p4d)
	627	return -ENOMEM;
	628	pud = vmemmap_pud_populate(p4d, addr, node);
29c71111 AW	629	if (!pud)
	630	return -ENOMEM;
	631	pmd = vmemmap_pmd_populate(pud, addr, node);
	632	if (!pmd)
	633	return -ENOMEM;
1d9cfee7	634	pte = vmemmap_pte_populate(pmd, addr, node, altmap);
29c71111 AW	635	if (!pte)
	636	return -ENOMEM;
	637	vmemmap_verify(pte, node, addr, addr + PAGE_SIZE);
8f6aac41	638	}
29c71111 AW	639
29c71111 AW	640	return 0;
8f6aac41	641	}
8f6aac41	642
e9c0a3f0 DW	643	struct page * __meminit __populate_section_memmap(unsigned long pfn,
e9c0a3f0 DW	644	unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
8f6aac41	645	{
6cda7204 WY	646	unsigned long start = (unsigned long) pfn_to_page(pfn);
	647	unsigned long end = start + nr_pages * sizeof(struct page);
	648
	649	if (WARN_ON_ONCE(!IS_ALIGNED(pfn, PAGES_PER_SUBSECTION) \|\|
	650	!IS_ALIGNED(nr_pages, PAGES_PER_SUBSECTION)))
	651	return NULL;
0aad818b	652
7b73d978	653	if (vmemmap_populate(start, end, nid, altmap))
8f6aac41 CL	654	return NULL;
8f6aac41 CL	655
e9c0a3f0	656	return pfn_to_page(pfn);
8f6aac41	657	}