hmm_pfn_to_page
if (bo->tbo.ttm->pages[i] != hmm_pfn_to_page(e->range->hmm_pfns[i])) {
ttm->pages[i] = range ? hmm_pfn_to_page(range->hmm_pfns[i]) : NULL;
page = hmm_pfn_to_page(hmm_pfns[i]);
struct page *page = hmm_pfn_to_page(pfns[i]);