* Mike Rapoport <[email protected]> [260211 05:32]: > From: "Mike Rapoport (Microsoft)" <[email protected]> > > my_zero_pfn() is a silly name. > > Rename zero_pfn variable to zero_page_pfn and my_zero_pfn() function to > zero_pfn(). > > While on it, move extern declarations of zero_page_pfn outside the > functions that use it and add a comment about what ZERO_PAGE is. > > Signed-off-by: Mike Rapoport (Microsoft) <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]> > --- > arch/x86/kvm/mmu/spte.h | 2 +- > fs/dax.c | 2 +- > fs/proc/vmcore.c | 2 +- > include/linux/pgtable.h | 28 ++++++++++++++++++++-------- > mm/huge_memory.c | 2 +- > mm/memory.c | 2 +- > mm/migrate.c | 2 +- > mm/mm_init.c | 10 +++++----- > mm/userfaultfd.c | 4 ++-- > 9 files changed, 33 insertions(+), 21 deletions(-) > > diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h > index 91ce29fd6f1b..8c0ffa2cded6 100644 > --- a/arch/x86/kvm/mmu/spte.h > +++ b/arch/x86/kvm/mmu/spte.h > @@ -248,7 +248,7 @@ extern u64 __read_mostly > shadow_nonpresent_or_rsvd_lower_gfn_mask; > > static inline hpa_t kvm_mmu_get_dummy_root(void) > { > - return my_zero_pfn(0) << PAGE_SHIFT; > + return zero_pfn(0) << PAGE_SHIFT; > } > > static inline bool kvm_mmu_is_dummy_root(hpa_t shadow_page) > diff --git a/fs/dax.c b/fs/dax.c > index 289e6254aa30..b78cff9c91b3 100644 > --- a/fs/dax.c > +++ b/fs/dax.c > @@ -1360,7 +1360,7 @@ static vm_fault_t dax_load_hole(struct xa_state *xas, > struct vm_fault *vmf, > { > struct inode *inode = iter->inode; > unsigned long vaddr = vmf->address; > - unsigned long pfn = my_zero_pfn(vaddr); > + unsigned long pfn = zero_pfn(vaddr); > vm_fault_t ret; > > *entry = dax_insert_entry(xas, vmf, iter, *entry, pfn, DAX_ZERO_PAGE); > diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c > index f188bd900eb2..44d15436439f 100644 > --- a/fs/proc/vmcore.c > +++ b/fs/proc/vmcore.c > @@ -525,7 +525,7 @@ static int remap_oldmem_pfn_checked(struct vm_area_struct > *vma, > { > unsigned long map_size; > unsigned long pos_start, pos_end, pos; > - unsigned long zeropage_pfn = my_zero_pfn(0); > + unsigned long zeropage_pfn = zero_pfn(0); > size_t len = 0; > > pos_start = pfn; > diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h > index 08a88b0d56e5..9bacf4df9769 100644 > --- a/include/linux/pgtable.h > +++ b/include/linux/pgtable.h > @@ -1882,27 +1882,39 @@ static inline void > pfnmap_setup_cachemode_pfn(unsigned long pfn, pgprot_t *prot) > pfnmap_setup_cachemode(pfn, PAGE_SIZE, prot); > } > > +/* > + * ZERO_PAGE() is global shared page(s) that is always zero. It is used for > + * zero-mapped memory areas, CoW etc. > + * > + * On architectures that __HAVE_COLOR_ZERO_PAGE there are several such pages > + * for different ranges in the virtual address space. > + * > + * zero_page_pfn identifies the first (or the only) pfn for these pages. > + */ > #ifdef __HAVE_COLOR_ZERO_PAGE > static inline int is_zero_pfn(unsigned long pfn) > { > - extern unsigned long zero_pfn; > - unsigned long offset_from_zero_pfn = pfn - zero_pfn; > + extern unsigned long zero_page_pfn; > + unsigned long offset_from_zero_pfn = pfn - zero_page_pfn; > + > return offset_from_zero_pfn <= (zero_page_mask >> PAGE_SHIFT); > } > > -#define my_zero_pfn(addr) page_to_pfn(ZERO_PAGE(addr)) > +#define zero_pfn(addr) page_to_pfn(ZERO_PAGE(addr)) > > #else > static inline int is_zero_pfn(unsigned long pfn) > { > - extern unsigned long zero_pfn; > - return pfn == zero_pfn; > + extern unsigned long zero_page_pfn; > + > + return pfn == zero_page_pfn; > } > > -static inline unsigned long my_zero_pfn(unsigned long addr) > +static inline unsigned long zero_pfn(unsigned long addr) > { > - extern unsigned long zero_pfn; > - return zero_pfn; > + extern unsigned long zero_page_pfn; > + > + return zero_page_pfn; > } > #endif /* __HAVE_COLOR_ZERO_PAGE */ > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 44ff8a648afd..bc15fd152526 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -2968,7 +2968,7 @@ static void __split_huge_zero_page_pmd(struct > vm_area_struct *vma, > for (i = 0, addr = haddr; i < HPAGE_PMD_NR; i++, addr += PAGE_SIZE) { > pte_t entry; > > - entry = pfn_pte(my_zero_pfn(addr), vma->vm_page_prot); > + entry = pfn_pte(zero_pfn(addr), vma->vm_page_prot); > entry = pte_mkspecial(entry); > if (pmd_uffd_wp(old_pmd)) > entry = pte_mkuffd_wp(entry); > diff --git a/mm/memory.c b/mm/memory.c > index 51d2018a387a..ae610afa9cea 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -5165,7 +5165,7 @@ static vm_fault_t do_anonymous_page(struct vm_fault > *vmf) > /* Use the zero-page for reads */ > if (!(vmf->flags & FAULT_FLAG_WRITE) && > !mm_forbids_zeropage(vma->vm_mm)) { > - entry = pte_mkspecial(pfn_pte(my_zero_pfn(vmf->address), > + entry = pte_mkspecial(pfn_pte(zero_pfn(vmf->address), > vma->vm_page_prot)); > vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, > vmf->address, &vmf->ptl); > diff --git a/mm/migrate.c b/mm/migrate.c > index 1bf2cf8c44dd..739c4e03769b 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -321,7 +321,7 @@ static bool try_to_map_unused_to_zeropage(struct > page_vma_mapped_walk *pvmw, > if (!pages_identical(page, ZERO_PAGE(0))) > return false; > > - newpte = pte_mkspecial(pfn_pte(my_zero_pfn(pvmw->address), > + newpte = pte_mkspecial(pfn_pte(zero_pfn(pvmw->address), > pvmw->vma->vm_page_prot)); > > if (pte_swp_soft_dirty(old_pte)) > diff --git a/mm/mm_init.c b/mm/mm_init.c > index dcf9eff34f83..a0ca236eb4f5 100644 > --- a/mm/mm_init.c > +++ b/mm/mm_init.c > @@ -53,8 +53,8 @@ EXPORT_SYMBOL(mem_map); > void *high_memory; > EXPORT_SYMBOL(high_memory); > > -unsigned long zero_pfn __ro_after_init; > -EXPORT_SYMBOL(zero_pfn); > +unsigned long zero_page_pfn __ro_after_init; > +EXPORT_SYMBOL(zero_page_pfn); > > #ifdef CONFIG_DEBUG_MEMORY_INIT > int __meminitdata mminit_loglevel; > @@ -2670,12 +2670,12 @@ static void __init mem_init_print_info(void) > ); > } > > -static int __init init_zero_pfn(void) > +static int __init init_zero_page_pfn(void) > { > - zero_pfn = page_to_pfn(ZERO_PAGE(0)); > + zero_page_pfn = page_to_pfn(ZERO_PAGE(0)); > return 0; > } > -early_initcall(init_zero_pfn); > +early_initcall(init_zero_page_pfn); > > void __init __weak arch_mm_preinit(void) > { > diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c > index 927086bb4a3c..e19872e51878 100644 > --- a/mm/userfaultfd.c > +++ b/mm/userfaultfd.c > @@ -357,7 +357,7 @@ static int mfill_atomic_pte_zeropage(pmd_t *dst_pmd, > if (mm_forbids_zeropage(dst_vma->vm_mm)) > return mfill_atomic_pte_zeroed_folio(dst_pmd, dst_vma, > dst_addr); > > - _dst_pte = pte_mkspecial(pfn_pte(my_zero_pfn(dst_addr), > + _dst_pte = pte_mkspecial(pfn_pte(zero_pfn(dst_addr), > dst_vma->vm_page_prot)); > ret = -EAGAIN; > dst_pte = pte_offset_map_lock(dst_vma->vm_mm, dst_pmd, dst_addr, &ptl); > @@ -1229,7 +1229,7 @@ static int move_zeropage_pte(struct mm_struct *mm, > return -EAGAIN; > } > > - zero_pte = pte_mkspecial(pfn_pte(my_zero_pfn(dst_addr), > + zero_pte = pte_mkspecial(pfn_pte(zero_pfn(dst_addr), > dst_vma->vm_page_prot)); > ptep_clear_flush(src_vma, src_addr, src_pte); > set_pte_at(mm, dst_addr, dst_pte, zero_pte); > -- > 2.51.0 >
