__vm_insert

static vm_fault_t __vm_insert_mixed(struct vm_area_struct *vma,
        unsigned long addr, pfn_t pfn, bool mkwrite)
{
    pgprot_t pgprot = vma->vm_page_prot;
    int err;
 
    BUG_ON(!vm_mixed_ok(vma, pfn));
 
    if (addr < vma->vm_start || addr >= vma->vm_end)
        return VM_FAULT_SIGBUS;
 
    track_pfn_insert(vma, &pgprot, pfn);
 
    if (!pfn_modify_allowed(pfn_t_to_pfn(pfn), pgprot))
        return VM_FAULT_SIGBUS;
 
    /*
     * If we don't have pte special, then we have to use the pfn_valid()
     * based VM_MIXEDMAP scheme (see vm_normal_page), and thus we *must*
     * refcount the page if pfn_valid is true (hence insert_page rather
     * than insert_pfn).  If a zero_pfn were inserted into a VM_MIXEDMAP
     * without pte special, it would there be refcounted as a normal page.
     */
    if (!IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) &&
        !pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
        struct page *page;
 
        /*
         * At this point we are committed to insert_page()
         * regardless of whether the caller specified flags that
         * result in pfn_t_has_page() == false.
         */
        page = pfn_to_page(pfn_t_to_pfn(pfn));
        err = insert_page(vma, addr, page, pgprot);
    } else {
        return insert_pfn(vma, addr, pfn, pgprot, mkwrite);
    }
 
    if (err == -ENOMEM)
        return VM_FAULT_OOM;
    if (err < 0 && err != -EBUSY)
        return VM_FAULT_SIGBUS;
 
    return VM_FAULT_NOPAGE;
}
函数源码
