Steven Price <steven.price@xxxxxxx> writes: > Exposing the pud/pgd levels of the page tables to walk_page_range() means > we may come across the exotic large mappings that come with large areas > of contiguous memory (such as the kernel's linear map). > > For architectures that don't provide all p?d_leaf() macros, provide > generic do nothing default that are suitable where there cannot be leaf > pages at that level. Futher patches will add implementations for > individual architectures. > > The name p?d_leaf() is chosen to minimize the confusion with existing > uses of "large" pages and "huge" pages which do not necessary mean that > the entry is a leaf (for example it may be a set of contiguous entries > that only take 1 TLB slot). For the purpose of walking the page tables > we don't need to know how it will be represented in the TLB, but we do > need to know for sure if it is a leaf of the tree. > > Signed-off-by: Steven Price <steven.price@xxxxxxx> > Acked-by: Mark Rutland <mark.rutland@xxxxxxx> > --- > include/asm-generic/pgtable.h | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) > > diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h > index 798ea36a0549..e2e2bef07dd2 100644 > --- a/include/asm-generic/pgtable.h > +++ b/include/asm-generic/pgtable.h > @@ -1238,4 +1238,24 @@ static inline bool arch_has_pfn_modify_check(void) > #define mm_pmd_folded(mm) __is_defined(__PAGETABLE_PMD_FOLDED) > #endif > > +/* > + * p?d_leaf() - true if this entry is a final mapping to a physical address. > + * This differs from p?d_huge() by the fact that they are always available (if > + * the architecture supports large pages at the appropriate level) even > + * if CONFIG_HUGETLB_PAGE is not defined. > + * Only meaningful when called on a valid entry. > + */ > +#ifndef pgd_leaf > +#define pgd_leaf(x) 0 > +#endif > +#ifndef p4d_leaf > +#define p4d_leaf(x) 0 > +#endif > +#ifndef pud_leaf > +#define pud_leaf(x) 0 > +#endif > +#ifndef pmd_leaf > +#define pmd_leaf(x) 0 > +#endif Any reason you made these #defines rather than static inlines? cheers
