@@ -3227,13 +3227,6 @@ static inline void print_vma_addr(char *prefix, unsigned long rip)
}
#endif
-#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
-int vmemmap_remap_free(unsigned long start, unsigned long end,
- unsigned long reuse);
-int vmemmap_remap_alloc(unsigned long start, unsigned long end,
- unsigned long reuse, gfp_t gfp_mask);
-#endif
-
void *sparse_buffer_alloc(unsigned long size);
struct page * __populate_section_memmap(unsigned long pfn,
unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
@@ -10,9 +10,31 @@
*/
#define pr_fmt(fmt) "HugeTLB: " fmt
-#include <linux/memory.h>
+#include <linux/pgtable.h>
+#include <linux/bootmem_info.h>
+#include <asm/pgalloc.h>
+#include <asm/tlbflush.h>
#include "hugetlb_vmemmap.h"
+/**
+ * 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;
+};
+
/*
* There are a lot of struct page structures associated with each HugeTLB page.
* For tail pages, the value of compound_head is the same. So we can reuse first
@@ -23,6 +45,381 @@
#define RESERVE_VMEMMAP_NR 1U
#define RESERVE_VMEMMAP_SIZE (RESERVE_VMEMMAP_NR << PAGE_SHIFT)
+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))) {
+ /*
+ * Higher order allocations from buddy allocator must be able to
+ * be treated as indepdenent small pages (as they can be freed
+ * individually).
+ */
+ if (!PageReserved(page))
+ split_page(page, get_order(PMD_SIZE));
+
+ /* 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(!PAGE_ALIGNED(start));
+ VM_BUG_ON(!PAGE_ALIGNED(end));
+
+ 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.
+ */
+static 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.
+ */
+static 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;
+}
+
DEFINE_STATIC_KEY_FALSE(hugetlb_optimize_vmemmap_key);
EXPORT_SYMBOL(hugetlb_optimize_vmemmap_key);
@@ -27,408 +27,9 @@
#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))) {
- /*
- * Higher order allocations from buddy allocator must be able to
- * be treated as indepdenent small pages (as they can be freed
- * individually).
- */
- if (!PageReserved(page))
- split_page(page, get_order(PMD_SIZE));
-
- /* 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(!PAGE_ALIGNED(start));
- VM_BUG_ON(!PAGE_ALIGNED(end));
-
- 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