centos man page for vm_insert_page

VM_INSERT_PAGE(9)					    Memory Management in Linux						 VM_INSERT_PAGE(9)

NAME
       vm_insert_page - insert single page into user vma

SYNOPSIS
       int vm_insert_page(struct vm_area_struct * vma, unsigned long addr, struct page * page);

ARGUMENTS
       vma
	   user vma to map to

       addr
	   target user address of this page

       page
	   source kernel page

DESCRIPTION
       This allows drivers to insert individual pages they've allocated into a user vma.

       The page has to be a nice clean _individual_ kernel allocation. If you allocate a compound page, you need to have marked it as such
       (__GFP_COMP), or manually just split the page up yourself (see split_page).

       NOTE! Traditionally this was done with "remap_pfn_range" which took an arbitrary page protection parameter. This doesn't allow that. Your
       vma protection will have to be set up correctly, which means that if you want a shared writable mapping, you'd better ask for a shared
       writable mapping!

       The page does not need to be reserved.

       Usually this function is called from f_op->mmap handler under mm->mmap_sem write-lock, so it can change vma->vm_flags. Caller must set
       VM_MIXEDMAP on vma if it wants to call this function from other places, for example from page-fault handler.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014							 VM_INSERT_PAGE(9)