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-rw-r--r--mm/vmalloc.c38
1 files changed, 38 insertions, 0 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index af77e171e339..e4c59a30835b 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -166,6 +166,44 @@ int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
}
EXPORT_SYMBOL_GPL(map_vm_area);
+/*
+ * Map a vmalloc()-space virtual address to the physical page.
+ */
+struct page *vmalloc_to_page(void *vmalloc_addr)
+{
+ unsigned long addr = (unsigned long) vmalloc_addr;
+ struct page *page = NULL;
+ pgd_t *pgd = pgd_offset_k(addr);
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *ptep, pte;
+
+ if (!pgd_none(*pgd)) {
+ pud = pud_offset(pgd, addr);
+ if (!pud_none(*pud)) {
+ pmd = pmd_offset(pud, addr);
+ if (!pmd_none(*pmd)) {
+ ptep = pte_offset_map(pmd, addr);
+ pte = *ptep;
+ if (pte_present(pte))
+ page = pte_page(pte);
+ pte_unmap(ptep);
+ }
+ }
+ }
+ return page;
+}
+EXPORT_SYMBOL(vmalloc_to_page);
+
+/*
+ * Map a vmalloc()-space virtual address to the physical page frame number.
+ */
+unsigned long vmalloc_to_pfn(void *vmalloc_addr)
+{
+ return page_to_pfn(vmalloc_to_page(vmalloc_addr));
+}
+EXPORT_SYMBOL(vmalloc_to_pfn);
+
static struct vm_struct *__get_vm_area_node(unsigned long size, unsigned long flags,
unsigned long start, unsigned long end,
int node, gfp_t gfp_mask)