On 19/12/2019 11:49, Michael Ellerman wrote: > Steven Price <[email protected]> writes: >> walk_page_range() is going to be allowed to walk page tables other than >> those of user space. For this it needs to know when it has reached a >> 'leaf' entry in the page tables. This information is provided by the >> p?d_leaf() functions/macros. >> >> For powerpc p?d_is_leaf() functions already exist. Export them using the >> new p?d_leaf() name. >> >> CC: Benjamin Herrenschmidt <[email protected]> >> CC: Paul Mackerras <[email protected]> >> CC: Michael Ellerman <[email protected]> >> CC: [email protected] >> CC: [email protected] >> Signed-off-by: Steven Price <[email protected]> >> --- >> arch/powerpc/include/asm/book3s/64/pgtable.h | 3 +++ >> 1 file changed, 3 insertions(+) > > We have fallback versions of our pmd_is_leaf() etc. in > arch/powerpc/include/asm/pgtable.h, eg: > > #ifndef pmd_is_leaf > #define pmd_is_leaf pmd_is_leaf > static inline bool pmd_is_leaf(pmd_t pmd) > { > return false; > } > #endif > > Because we support several different MMUs and most of them don't need to > do anything. > > So we could put the compatibility #defines to your names along with the > fallback versions in asm/pgtable.h, rather than in > asm/book3s/64/pgtable.h > > But I see you also have fallbacks for your versions, so it probably > doesn't matter either way. > > So I'm OK with this version, unless you think there's a compelling > reason to do the compatibility #defines in our asm/pgtable.h
I was thinking that (assuming this series actually gets merged this time), the p?d_is_leaf() versions could be removed and replaced by p?d_leaf() in the future. Since the fallbacks are in the asm-generic code it makes sense for the pmd_leaf() definitions to be next to the non-fallback versions. > Acked-by: Michael Ellerman <[email protected]> Thanks! Steve > cheers > > >> diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h >> b/arch/powerpc/include/asm/book3s/64/pgtable.h >> index b01624e5c467..201a69e6a355 100644 >> --- a/arch/powerpc/include/asm/book3s/64/pgtable.h >> +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h >> @@ -1355,18 +1355,21 @@ static inline bool is_pte_rw_upgrade(unsigned long >> old_val, unsigned long new_va >> * Like pmd_huge() and pmd_large(), but works regardless of config options >> */ >> #define pmd_is_leaf pmd_is_leaf >> +#define pmd_leaf pmd_is_leaf >> static inline bool pmd_is_leaf(pmd_t pmd) >> { >> return !!(pmd_raw(pmd) & cpu_to_be64(_PAGE_PTE)); >> } >> >> #define pud_is_leaf pud_is_leaf >> +#define pud_leaf pud_is_leaf >> static inline bool pud_is_leaf(pud_t pud) >> { >> return !!(pud_raw(pud) & cpu_to_be64(_PAGE_PTE)); >> } >> >> #define pgd_is_leaf pgd_is_leaf >> +#define pgd_leaf pgd_is_leaf >> static inline bool pgd_is_leaf(pgd_t pgd) >> { >> return !!(pgd_raw(pgd) & cpu_to_be64(_PAGE_PTE)); >> -- >> 2.20.1 > > _______________________________________________ > linux-arm-kernel mailing list > [email protected] > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >
