On 11/28/22 11:37, Alexander Gordeev wrote: > On Fri, Nov 25, 2022 at 09:15:02AM +0530, Anshuman Khandual wrote: > > Hi Anshuman, > >> In __gmap_segment_gaddr() pmd level page table page is being extracted from >> the pmd pointer, similar to pmd_pgtable_page() implementation. This reduces >> some redundancy by directly using pmd_pgtable_page() instead, though first >> making it available. > > [...] > >> diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c >> index 02d15c8dc92e..8947451ae021 100644 >> --- a/arch/s390/mm/gmap.c >> +++ b/arch/s390/mm/gmap.c >> @@ -336,12 +336,11 @@ static int gmap_alloc_table(struct gmap *gmap, unsigned long *table, >> static unsigned long __gmap_segment_gaddr(unsigned long *entry) >> { >> struct page *page; >> - unsigned long offset, mask; >> + unsigned long offset; >> >> offset = (unsigned long) entry / sizeof(unsigned long); >> offset = (offset & (PTRS_PER_PMD - 1)) * PMD_SIZE; >> - mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1); >> - page = virt_to_page((void *)((unsigned long) entry & mask)); >> + page = pmd_pgtable_page((pmd_t *) entry); >> return page->index + offset; >> } > > Looks okay to me. > >> diff --git a/include/linux/mm.h b/include/linux/mm.h >> index e9e387caffac..5ead9e997510 100644 >> --- a/include/linux/mm.h >> +++ b/include/linux/mm.h >> @@ -2403,7 +2403,7 @@ static inline void pgtable_pte_page_dtor(struct page *page) >> >> #if USE_SPLIT_PMD_PTLOCKS >> >> -static struct page *pmd_pgtable_page(pmd_t *pmd) >> +static inline struct page *pmd_pgtable_page(pmd_t *pmd) >> { >> unsigned long mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1); >> return virt_to_page((void *)((unsigned long) pmd & mask)); > > This chunk does not appear to belong to this patch. Should not this helper be made a 'static inline' before using it else where ?