> > +int kernel_unmap_pages_in_pgd(pgd_t *pgd, unsigned long address,
> > + unsigned long numpages)
> > +{
> > + int retval;
> > +
> > + /*
> > + * The typical sequence for unmapping is to find a pte through
> > + * lookup_address_in_pgd() (ideally, it should never return NULL
> because
> > + * the address is already mapped) and change it's protections.
> > + * As pfn is the *target* of a mapping, it's not useful while unmapping.
> > + */
> > + struct cpa_data cpa = {
> > + .vaddr = &address,
> > + .pgd = pgd,
> > + .numpages = numpages,
> > + .mask_set = __pgprot(0),
> > + .mask_clr = __pgprot(_PAGE_PRESENT | _PAGE_RW),
> > + .flags = 0,
> > + };
> > +
> > + retval = __change_page_attr_set_clr(&cpa, 0);
> > + __flush_tlb_all();
>
> So, just to clarify, 'pfn' is kept at 0 here? Might make sense to write it out
> explicitly like 'flags', even if it's not used by
> __change_page_attr_set_clr().
Sure! Makes sense. I will add it.
Regards,
Sai
