follow_pfn - look up PFN at a user virtual address
2. SYNOPSIS ▲
int follow_pfn(struct vm_area_struct * vma , unsigned long address , unsigned long * pfn );
3. ARGUMENTS ▲
user virtual address
location to store found PFN
4. DESCRIPTION ▲
Only IO mappings and raw PFN mappings are allowed.
Returns zero and the pfn at pfn on success, -ve otherwise.
5. COPYRIGHT ▲