Alistair Popple wrote: > DAX no longer requires device PTEs as it always has a ZONE_DEVICE page > associated with the PTE that can be reference counted normally. Other users > of pte_devmap are drivers that set PFN_DEV when calling vmf_insert_mixed() > which ensures vm_normal_page() returns NULL for these entries. > > There is no reason to distinguish these pte_devmap users so in order to > free up a PTE bit use pte_special instead for entries created with > vmf_insert_mixed(). This will ensure vm_normal_page() will continue to > return NULL for these pages. > > Architectures that don't support pte_special also don't support pte_devmap > so those will continue to rely on pfn_valid() to determine if the page can > be mapped. Looks good, Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx>
