Re: [PATCH v17 06/23] powerpc: mm: Add p?d_leaf() definitions
From: Michael Ellerman <mpe@ellerman.id.au>
Date: 2019-12-19 11:49:24
Also in:
linux-arm-kernel, linux-mm, lkml
Steven Price [off-list ref] 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 <benh@kernel.crashing.org> CC: Paul Mackerras <redacted> CC: Michael Ellerman <mpe@ellerman.id.au> CC: linuxppc-dev@lists.ozlabs.org CC: kvm-ppc@vger.kernel.org Signed-off-by: Steven Price <steven.price@arm.com> --- 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
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
cheers
quoted hunk ↗ jump to hunk
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