Re: [PATCH] powerpc: add support for folded p4d page tables

Christophe Leroy
2020-01-02T16:42:31Z

Mike Rapoport <rppt@kernel.org> a écrit :

> Any updates on this?

Checkpatch reported several points, see
https://patchwork.ozlabs.org/patch/1206344/

Christophe

>
> On Mon, Dec 09, 2019 at 05:09:08PM +0200, Mike Rapoport wrote:
>> From: Mike Rapoport <rppt@linux.ibm.com>
>>
>> Implement primitives necessary for the 4th level folding, add walks of p4d
>> level where appropriate and replace 5level-fixup.h with pgtable-nop4d.h.
>>
>> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
>> ---
>> arch/powerpc/include/asm/book3s/32/pgtable.h | 1 -
>> arch/powerpc/include/asm/book3s/64/hash.h | 4 +-
>> arch/powerpc/include/asm/book3s/64/pgalloc.h | 4 +-
>> arch/powerpc/include/asm/book3s/64/pgtable.h | 58 ++++++++++--------
>> arch/powerpc/include/asm/book3s/64/radix.h | 6 +-
>> arch/powerpc/include/asm/nohash/32/pgtable.h | 1 -
>> arch/powerpc/include/asm/nohash/64/pgalloc.h | 2 +-
>> .../include/asm/nohash/64/pgtable-4k.h | 32 +++++-----
>> arch/powerpc/include/asm/nohash/64/pgtable.h | 6 +-
>> arch/powerpc/include/asm/pgtable.h | 8 +++
>> arch/powerpc/kvm/book3s_64_mmu_radix.c | 59 ++++++++++++++++---
>> arch/powerpc/lib/code-patching.c | 7 ++-
>> arch/powerpc/mm/book3s32/mmu.c | 2 +-
>> arch/powerpc/mm/book3s32/tlb.c | 4 +-
>> arch/powerpc/mm/book3s64/hash_pgtable.c | 4 +-
>> arch/powerpc/mm/book3s64/radix_pgtable.c | 19 ++++--
>> arch/powerpc/mm/book3s64/subpage_prot.c | 6 +-
>> arch/powerpc/mm/hugetlbpage.c | 28 +++++----
>> arch/powerpc/mm/kasan/kasan_init_32.c | 8 +--
>> arch/powerpc/mm/mem.c | 4 +-
>> arch/powerpc/mm/nohash/40x.c | 4 +-
>> arch/powerpc/mm/nohash/book3e_pgtable.c | 15 +++--
>> arch/powerpc/mm/pgtable.c | 25 +++++++-
>> arch/powerpc/mm/pgtable_32.c | 28 +++++----
>> arch/powerpc/mm/pgtable_64.c | 10 ++--
>> arch/powerpc/mm/ptdump/hashpagetable.c | 20 ++++++-
>> arch/powerpc/mm/ptdump/ptdump.c | 22 ++++++-
>> arch/powerpc/xmon/xmon.c | 17 +++++-
>> 28 files changed, 284 insertions(+), 120 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h
>> b/arch/powerpc/include/asm/book3s/32/pgtable.h
>> index 0796533d37dd..e23de69bbaf8 100644
>> --- a/arch/powerpc/include/asm/book3s/32/pgtable.h
>> +++ b/arch/powerpc/include/asm/book3s/32/pgtable.h
>> @@ -2,7 +2,6 @@
>> #ifndef _ASM_POWERPC_BOOK3S_32_PGTABLE_H
>> #define _ASM_POWERPC_BOOK3S_32_PGTABLE_H
>>
>> -#define __ARCH_USE_5LEVEL_HACK
>> #include <asm-generic/pgtable-nopmd.h>
>>
>> #include <asm/book3s/32/hash.h>
>> diff --git a/arch/powerpc/include/asm/book3s/64/hash.h
>> b/arch/powerpc/include/asm/book3s/64/hash.h
>> index 2781ebf6add4..876d1528c2cf 100644
>> --- a/arch/powerpc/include/asm/book3s/64/hash.h
>> +++ b/arch/powerpc/include/asm/book3s/64/hash.h
>> @@ -134,9 +134,9 @@ static inline int get_region_id(unsigned long ea)
>>
>> #define hash__pmd_bad(pmd) (pmd_val(pmd) & H_PMD_BAD_BITS)
>> #define hash__pud_bad(pud) (pud_val(pud) & H_PUD_BAD_BITS)
>> -static inline int hash__pgd_bad(pgd_t pgd)
>> +static inline int hash__p4d_bad(p4d_t p4d)
>> {
>> - return (pgd_val(pgd) == 0);
>> + return (p4d_val(p4d) == 0);
>> }
>> #ifdef CONFIG_STRICT_KERNEL_RWX
>> extern void hash__mark_rodata_ro(void);
>> diff --git a/arch/powerpc/include/asm/book3s/64/pgalloc.h
>> b/arch/powerpc/include/asm/book3s/64/pgalloc.h
>> index f6968c811026..08603089ea5f 100644
>> --- a/arch/powerpc/include/asm/book3s/64/pgalloc.h
>> +++ b/arch/powerpc/include/asm/book3s/64/pgalloc.h
>> @@ -87,9 +87,9 @@ static inline void pgd_free(struct mm_struct *mm,
>> pgd_t *pgd)
>> kmem_cache_free(PGT_CACHE(PGD_INDEX_SIZE), pgd);
>> }
>>
>> -static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd,
>> pud_t *pud)
>> +static inline void p4d_populate(struct mm_struct *mm, p4d_t *pgd,
>> pud_t *pud)
>> {
>> - *pgd = __pgd(__pgtable_ptr_val(pud) | PGD_VAL_BITS);
>> + *pgd = __p4d(__pgtable_ptr_val(pud) | PGD_VAL_BITS);
>> }
>>
>> static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned
>> long addr)
>> diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h
>> b/arch/powerpc/include/asm/book3s/64/pgtable.h
>> index b01624e5c467..96fc48a42f4d 100644
>> --- a/arch/powerpc/include/asm/book3s/64/pgtable.h
>> +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
>> @@ -2,7 +2,7 @@
>> #ifndef _ASM_POWERPC_BOOK3S_64_PGTABLE_H_
>> #define _ASM_POWERPC_BOOK3S_64_PGTABLE_H_
>>
>> -#include <asm-generic/5level-fixup.h>
>> +#include <asm-generic/pgtable-nop4d.h>
>>
>> #ifndef __ASSEMBLY__
>> #include <linux/mmdebug.h>
>> @@ -251,7 +251,7 @@ extern unsigned long __pmd_frag_size_shift;
>> /* Bits to mask out from a PUD to get to the PMD page */
>> #define PUD_MASKED_BITS 0xc0000000000000ffUL
>> /* Bits to mask out from a PGD to get to the PUD page */
>> -#define PGD_MASKED_BITS 0xc0000000000000ffUL
>> +#define P4D_MASKED_BITS 0xc0000000000000ffUL
>>
>> /*
>> * Used as an indicator for rcu callback functions
>> @@ -949,54 +949,60 @@ static inline bool pud_access_permitted(pud_t
>> pud, bool write)
>> return pte_access_permitted(pud_pte(pud), write);
>> }
>>
>> -#define pgd_write(pgd) pte_write(pgd_pte(pgd))
>> +#define __p4d_raw(x) ((p4d_t) { __pgd_raw(x) })
>> +static inline __be64 p4d_raw(p4d_t x)
>> +{
>> + return pgd_raw(x.pgd);
>> +}
>> +
>> +#define p4d_write(p4d) pte_write(p4d_pte(p4d))
>>
>> -static inline void pgd_clear(pgd_t *pgdp)
>> +static inline void p4d_clear(p4d_t *p4dp)
>> {
>> - *pgdp = __pgd(0);
>> + *p4dp = __p4d(0);
>> }
>>
>> -static inline int pgd_none(pgd_t pgd)
>> +static inline int p4d_none(p4d_t p4d)
>> {
>> - return !pgd_raw(pgd);
>> + return !p4d_raw(p4d);
>> }
>>
>> -static inline int pgd_present(pgd_t pgd)
>> +static inline int p4d_present(p4d_t p4d)
>> {
>> - return !!(pgd_raw(pgd) & cpu_to_be64(_PAGE_PRESENT));
>> + return !!(p4d_raw(p4d) & cpu_to_be64(_PAGE_PRESENT));
>> }
>>
>> -static inline pte_t pgd_pte(pgd_t pgd)
>> +static inline pte_t p4d_pte(p4d_t p4d)
>> {
>> - return __pte_raw(pgd_raw(pgd));
>> + return __pte_raw(p4d_raw(p4d));
>> }
>>
>> -static inline pgd_t pte_pgd(pte_t pte)
>> +static inline p4d_t pte_p4d(pte_t pte)
>> {
>> - return __pgd_raw(pte_raw(pte));
>> + return __p4d_raw(pte_raw(pte));
>> }
>>
>> -static inline int pgd_bad(pgd_t pgd)
>> +static inline int p4d_bad(p4d_t p4d)
>> {
>> if (radix_enabled())
>> - return radix__pgd_bad(pgd);
>> - return hash__pgd_bad(pgd);
>> + return radix__p4d_bad(p4d);
>> + return hash__p4d_bad(p4d);
>> }
>>
>> -#define pgd_access_permitted pgd_access_permitted
>> -static inline bool pgd_access_permitted(pgd_t pgd, bool write)
>> +#define p4d_access_permitted p4d_access_permitted
>> +static inline bool p4d_access_permitted(p4d_t p4d, bool write)
>> {
>> - return pte_access_permitted(pgd_pte(pgd), write);
>> + return pte_access_permitted(p4d_pte(p4d), write);
>> }
>>
>> -extern struct page *pgd_page(pgd_t pgd);
>> +extern struct page *p4d_page(p4d_t p4d);
>>
>> /* Pointers in the page table tree are physical addresses */
>> #define __pgtable_ptr_val(ptr) __pa(ptr)
>>
>> #define pmd_page_vaddr(pmd) __va(pmd_val(pmd) & ~PMD_MASKED_BITS)
>> #define pud_page_vaddr(pud) __va(pud_val(pud) & ~PUD_MASKED_BITS)
>> -#define pgd_page_vaddr(pgd) __va(pgd_val(pgd) & ~PGD_MASKED_BITS)
>> +#define p4d_page_vaddr(p4d) __va(p4d_val(p4d) & ~P4D_MASKED_BITS)
>>
>> #define pgd_index(address) (((address) >> (PGDIR_SHIFT)) &
>> (PTRS_PER_PGD - 1))
>> #define pud_index(address) (((address) >> (PUD_SHIFT)) &
>> (PTRS_PER_PUD - 1))
>> @@ -1010,8 +1016,8 @@ extern struct page *pgd_page(pgd_t pgd);
>>
>> #define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address))
>>
>> -#define pud_offset(pgdp, addr) \
>> - (((pud_t *) pgd_page_vaddr(*(pgdp))) + pud_index(addr))
>> +#define pud_offset(p4dp, addr) \
>> + (((pud_t *) p4d_page_vaddr(*(p4dp))) + pud_index(addr))
>> #define pmd_offset(pudp,addr) \
>> (((pmd_t *) pud_page_vaddr(*(pudp))) + pmd_index(addr))
>> #define pte_offset_kernel(dir,addr) \
>> @@ -1366,6 +1372,12 @@ static inline bool pud_is_leaf(pud_t pud)
>> return !!(pud_raw(pud) & cpu_to_be64(_PAGE_PTE));
>> }
>>
>> +#define p4d_is_leaf p4d_is_leaf
>> +static inline bool p4d_is_leaf(p4d_t p4d)
>> +{
>> + return !!(p4d_raw(p4d) & cpu_to_be64(_PAGE_PTE));
>> +}
>> +
>> #define pgd_is_leaf pgd_is_leaf
>> static inline bool pgd_is_leaf(pgd_t pgd)
>> {
>> diff --git a/arch/powerpc/include/asm/book3s/64/radix.h
>> b/arch/powerpc/include/asm/book3s/64/radix.h
>> index d97db3ad9aae..9bca2ac64220 100644
>> --- a/arch/powerpc/include/asm/book3s/64/radix.h
>> +++ b/arch/powerpc/include/asm/book3s/64/radix.h
>> @@ -30,7 +30,7 @@
>> /* Don't have anything in the reserved bits and leaf bits */
>> #define RADIX_PMD_BAD_BITS 0x60000000000000e0UL
>> #define RADIX_PUD_BAD_BITS 0x60000000000000e0UL
>> -#define RADIX_PGD_BAD_BITS 0x60000000000000e0UL
>> +#define RADIX_P4D_BAD_BITS 0x60000000000000e0UL
>>
>> #define RADIX_PMD_SHIFT (PAGE_SHIFT + RADIX_PTE_INDEX_SIZE)
>> #define RADIX_PUD_SHIFT (RADIX_PMD_SHIFT + RADIX_PMD_INDEX_SIZE)
>> @@ -227,9 +227,9 @@ static inline int radix__pud_bad(pud_t pud)
>> }
>>
>>
>> -static inline int radix__pgd_bad(pgd_t pgd)
>> +static inline int radix__p4d_bad(p4d_t p4d)
>> {
>> - return !!(pgd_val(pgd) & RADIX_PGD_BAD_BITS);
>> + return !!(p4d_val(p4d) & RADIX_P4D_BAD_BITS);
>> }
>>
>> #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>> diff --git a/arch/powerpc/include/asm/nohash/32/pgtable.h
>> b/arch/powerpc/include/asm/nohash/32/pgtable.h
>> index 552b96eef0c8..a0edcc7b0700 100644
>> --- a/arch/powerpc/include/asm/nohash/32/pgtable.h
>> +++ b/arch/powerpc/include/asm/nohash/32/pgtable.h
>> @@ -2,7 +2,6 @@
>> #ifndef _ASM_POWERPC_NOHASH_32_PGTABLE_H
>> #define _ASM_POWERPC_NOHASH_32_PGTABLE_H
>>
>> -#define __ARCH_USE_5LEVEL_HACK
>> #include <asm-generic/pgtable-nopmd.h>
>>
>> #ifndef __ASSEMBLY__
>> diff --git a/arch/powerpc/include/asm/nohash/64/pgalloc.h
>> b/arch/powerpc/include/asm/nohash/64/pgalloc.h
>> index b9534a793293..668aee6017e7 100644
>> --- a/arch/powerpc/include/asm/nohash/64/pgalloc.h
>> +++ b/arch/powerpc/include/asm/nohash/64/pgalloc.h
>> @@ -15,7 +15,7 @@ struct vmemmap_backing {
>> };
>> extern struct vmemmap_backing *vmemmap_list;
>>
>> -#define pgd_populate(MM, PGD, PUD) pgd_set(PGD, (unsigned long)PUD)
>> +#define p4d_populate(MM, P4D, PUD) p4d_set(P4D, (unsigned long)PUD)
>>
>> static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned
>> long addr)
>> {
>> diff --git a/arch/powerpc/include/asm/nohash/64/pgtable-4k.h
>> b/arch/powerpc/include/asm/nohash/64/pgtable-4k.h
>> index c40ec32b8194..81b1c54e3cf1 100644
>> --- a/arch/powerpc/include/asm/nohash/64/pgtable-4k.h
>> +++ b/arch/powerpc/include/asm/nohash/64/pgtable-4k.h
>> @@ -2,7 +2,7 @@
>> #ifndef _ASM_POWERPC_NOHASH_64_PGTABLE_4K_H
>> #define _ASM_POWERPC_NOHASH_64_PGTABLE_4K_H
>>
>> -#include <asm-generic/5level-fixup.h>
>> +#include <asm-generic/pgtable-nop4d.h>
>>
>> /*
>> * Entries per page directory level. The PTE level must use a 64b record
>> @@ -45,41 +45,41 @@
>> #define PMD_MASKED_BITS 0
>> /* Bits to mask out from a PUD to get to the PMD page */
>> #define PUD_MASKED_BITS 0
>> -/* Bits to mask out from a PGD to get to the PUD page */
>> -#define PGD_MASKED_BITS 0
>> +/* Bits to mask out from a P4D to get to the PUD page */
>> +#define P4D_MASKED_BITS 0
>>
>>
>> /*
>> * 4-level page tables related bits
>> */
>>
>> -#define pgd_none(pgd) (!pgd_val(pgd))
>> -#define pgd_bad(pgd) (pgd_val(pgd) == 0)
>> -#define pgd_present(pgd) (pgd_val(pgd) != 0)
>> -#define pgd_page_vaddr(pgd) (pgd_val(pgd) & ~PGD_MASKED_BITS)
>> +#define p4d_none(p4d) (!p4d_val(p4d))
>> +#define p4d_bad(p4d) (p4d_val(p4d) == 0)
>> +#define p4d_present(p4d) (p4d_val(p4d) != 0)
>> +#define p4d_page_vaddr(p4d) (p4d_val(p4d) & ~P4D_MASKED_BITS)
>>
>> #ifndef __ASSEMBLY__
>>
>> -static inline void pgd_clear(pgd_t *pgdp)
>> +static inline void p4d_clear(p4d_t *p4dp)
>> {
>> - *pgdp = __pgd(0);
>> + *p4dp = __p4d(0);
>> }
>>
>> -static inline pte_t pgd_pte(pgd_t pgd)
>> +static inline pte_t p4d_pte(p4d_t p4d)
>> {
>> - return __pte(pgd_val(pgd));
>> + return __pte(p4d_val(p4d));
>> }
>>
>> -static inline pgd_t pte_pgd(pte_t pte)
>> +static inline p4d_t pte_p4d(pte_t pte)
>> {
>> - return __pgd(pte_val(pte));
>> + return __p4d(pte_val(pte));
>> }
>> -extern struct page *pgd_page(pgd_t pgd);
>> +extern struct page *p4d_page(p4d_t p4d);
>>
>> #endif /* !__ASSEMBLY__ */
>>
>> -#define pud_offset(pgdp, addr) \
>> - (((pud_t *) pgd_page_vaddr(*(pgdp))) + \
>> +#define pud_offset(p4dp, addr) \
>> + (((pud_t *) p4d_page_vaddr(*(p4dp))) + \
>> (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1)))
>>
>> #define pud_ERROR(e) \
>> diff --git a/arch/powerpc/include/asm/nohash/64/pgtable.h
>> b/arch/powerpc/include/asm/nohash/64/pgtable.h
>> index 9a33b8bd842d..b360f262b9c6 100644
>> --- a/arch/powerpc/include/asm/nohash/64/pgtable.h
>> +++ b/arch/powerpc/include/asm/nohash/64/pgtable.h
>> @@ -175,11 +175,11 @@ static inline pud_t pte_pud(pte_t pte)
>> return __pud(pte_val(pte));
>> }
>> #define pud_write(pud) pte_write(pud_pte(pud))
>> -#define pgd_write(pgd) pte_write(pgd_pte(pgd))
>> +#define p4d_write(pgd) pte_write(p4d_pte(p4d))
>>
>> -static inline void pgd_set(pgd_t *pgdp, unsigned long val)
>> +static inline void p4d_set(p4d_t *p4dp, unsigned long val)
>> {
>> - *pgdp = __pgd(val);
>> + *p4dp = __p4d(val);
>> }
>>
>> /*
>> diff --git a/arch/powerpc/include/asm/pgtable.h
>> b/arch/powerpc/include/asm/pgtable.h
>> index 0e4ec8cc37b7..f831b4d866c3 100644
>> --- a/arch/powerpc/include/asm/pgtable.h
>> +++ b/arch/powerpc/include/asm/pgtable.h
>> @@ -145,6 +145,14 @@ static inline bool pud_is_leaf(pud_t pud)
>> }
>> #endif
>>
>> +#ifndef p4d_is_leaf
>> +#define p4d_is_leaf p4d_is_leaf
>> +static inline bool p4d_is_leaf(p4d_t p4d)
>> +{
>> + return false;
>> +}
>> +#endif
>> +
>> #ifndef pgd_is_leaf
>> #define pgd_is_leaf pgd_is_leaf
>> static inline bool pgd_is_leaf(pgd_t pgd)
>> diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c
>> b/arch/powerpc/kvm/book3s_64_mmu_radix.c
>> index da857c8ba6e4..28e166cbd963 100644
>> --- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
>> +++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
>> @@ -496,17 +496,39 @@ static void kvmppc_unmap_free_pud(struct kvm
>> *kvm, pud_t *pud,
>> pud_free(kvm->mm, pud);
>> }
>>
>> +static void kvmppc_unmap_free_p4d(struct kvm *kvm, p4d_t *p4d,
>> + unsigned int lpid)
>> +{
>> + unsigned long iu;
>> + p4d_t *p = p4d;
>> +
>> + for (iu = 0; iu < PTRS_PER_P4D; ++iu, ++p) {
>> + if (!p4d_present(*p))
>> + continue;
>> + if (p4d_is_leaf(*p)) {
>> + p4d_clear(p);
>> + } else {
>> + pud_t *pud;
>> +
>> + pud = pud_offset(p, 0);
>> + kvmppc_unmap_free_pud(kvm, pud, lpid);
>> + p4d_clear(p);
>> + }
>> + }
>> + p4d_free(kvm->mm, p4d);
>> +}
>> +
>> void kvmppc_free_pgtable_radix(struct kvm *kvm, pgd_t *pgd,
>> unsigned int lpid)
>> {
>> unsigned long ig;
>>
>> for (ig = 0; ig < PTRS_PER_PGD; ++ig, ++pgd) {
>> - pud_t *pud;
>> + p4d_t *p4d;
>>
>> if (!pgd_present(*pgd))
>> continue;
>> - pud = pud_offset(pgd, 0);
>> - kvmppc_unmap_free_pud(kvm, pud, lpid);
>> + p4d = p4d_offset(pgd, 0);
>> + kvmppc_unmap_free_p4d(kvm, p4d, lpid);
>> pgd_clear(pgd);
>> }
>> }
>> @@ -568,6 +590,7 @@ int kvmppc_create_pte(struct kvm *kvm, pgd_t
>> *pgtable, pte_t pte,
>> unsigned long *rmapp, struct rmap_nested **n_rmap)
>> {
>> pgd_t *pgd;
>> + p4d_t *p4d, *new_p4d = NULL;
>> pud_t *pud, *new_pud = NULL;
>> pmd_t *pmd, *new_pmd = NULL;
>> pte_t *ptep, *new_ptep = NULL;
>> @@ -575,9 +598,15 @@ int kvmppc_create_pte(struct kvm *kvm, pgd_t
>> *pgtable, pte_t pte,
>>
>> /* Traverse the guest's 2nd-level tree, allocate new levels needed */
>> pgd = pgtable + pgd_index(gpa);
>> - pud = NULL;
>> + p4d = NULL;
>> if (pgd_present(*pgd))
>> - pud = pud_offset(pgd, gpa);
>> + p4d = p4d_offset(pgd, gpa);
>> + else
>> + new_p4d = p4d_alloc_one(kvm->mm, gpa);
>> +
>> + pud = NULL;
>> + if (p4d_present(*p4d))
>> + pud = pud_offset(p4d, gpa);
>> else
>> new_pud = pud_alloc_one(kvm->mm, gpa);
>>
>> @@ -599,12 +628,18 @@ int kvmppc_create_pte(struct kvm *kvm, pgd_t
>> *pgtable, pte_t pte,
>> /* Now traverse again under the lock and change the tree */
>> ret = -ENOMEM;
>> if (pgd_none(*pgd)) {
>> + if (!new_p4d)
>> + goto out_unlock;
>> + pgd_populate(kvm->mm, pgd, new_p4d);
>> + new_p4d = NULL;
>> + }
>> + if (p4d_none(*p4d)) {
>> if (!new_pud)
>> goto out_unlock;
>> - pgd_populate(kvm->mm, pgd, new_pud);
>> + p4d_populate(kvm->mm, p4d, new_pud);
>> new_pud = NULL;
>> }
>> - pud = pud_offset(pgd, gpa);
>> + pud = pud_offset(p4d, gpa);
>> if (pud_is_leaf(*pud)) {
>> unsigned long hgpa = gpa & PUD_MASK;
>>
>> @@ -1222,6 +1257,7 @@ static ssize_t debugfs_radix_read(struct file
>> *file, char __user *buf,
>> pgd_t *pgt;
>> struct kvm_nested_guest *nested;
>> pgd_t pgd, *pgdp;
>> + p4d_t p4d, *p4dp;
>> pud_t pud, *pudp;
>> pmd_t pmd, *pmdp;
>> pte_t *ptep;
>> @@ -1300,7 +1336,14 @@ static ssize_t debugfs_radix_read(struct
>> file *file, char __user *buf,
>> continue;
>> }
>>
>> - pudp = pud_offset(&pgd, gpa);
>> + p4dp = p4d_offset(&pgd, gpa);
>> + p4d = READ_ONCE(*p4dp);
>> + if (!(p4d_val(p4d) & _PAGE_PRESENT)) {
>> + gpa = (gpa & P4D_MASK) + P4D_SIZE;
>> + continue;
>> + }
>> +
>> + pudp = pud_offset(&p4d, gpa);
>> pud = READ_ONCE(*pudp);
>> if (!(pud_val(pud) & _PAGE_PRESENT)) {
>> gpa = (gpa & PUD_MASK) + PUD_SIZE;
>> diff --git a/arch/powerpc/lib/code-patching.c
>> b/arch/powerpc/lib/code-patching.c
>> index 3345f039a876..7a59f6863cec 100644
>> --- a/arch/powerpc/lib/code-patching.c
>> +++ b/arch/powerpc/lib/code-patching.c
>> @@ -107,13 +107,18 @@ static inline int unmap_patch_area(unsigned long addr)
>> pte_t *ptep;
>> pmd_t *pmdp;
>> pud_t *pudp;
>> + p4d_t *p4dp;
>> pgd_t *pgdp;
>>
>> pgdp = pgd_offset_k(addr);
>> if (unlikely(!pgdp))
>> return -EINVAL;
>>
>> - pudp = pud_offset(pgdp, addr);
>> + p4dp = p4d_offset(pgdp, addr);
>> + if (unlikely(!p4dp))
>> + return -EINVAL;
>> +
>> + pudp = pud_offset(p4dp, addr);
>> if (unlikely(!pudp))
>> return -EINVAL;
>>
>> diff --git a/arch/powerpc/mm/book3s32/mmu.c b/arch/powerpc/mm/book3s32/mmu.c
>> index 69b2419accef..7479960dc434 100644
>> --- a/arch/powerpc/mm/book3s32/mmu.c
>> +++ b/arch/powerpc/mm/book3s32/mmu.c
>> @@ -312,7 +312,7 @@ void hash_preload(struct mm_struct *mm,
>> unsigned long ea)
>>
>> if (!Hash)
>> return;
>> - pmd = pmd_offset(pud_offset(pgd_offset(mm, ea), ea), ea);
>> + pmd = pmd_offset(pud_offset(p4d_offset(pgd_offset(mm, ea), ea), ea), ea);
>> if (!pmd_none(*pmd))
>> add_hash_page(mm->context.id, ea, pmd_val(*pmd));
>> }
>> diff --git a/arch/powerpc/mm/book3s32/tlb.c b/arch/powerpc/mm/book3s32/tlb.c
>> index 2fcd321040ff..175bc33b41b7 100644
>> --- a/arch/powerpc/mm/book3s32/tlb.c
>> +++ b/arch/powerpc/mm/book3s32/tlb.c
>> @@ -87,7 +87,7 @@ static void flush_range(struct mm_struct *mm,
>> unsigned long start,
>> if (start >= end)
>> return;
>> end = (end - 1) | ~PAGE_MASK;
>> - pmd = pmd_offset(pud_offset(pgd_offset(mm, start), start), start);
>> + pmd = pmd_offset(pud_offset(p4d_offset(pgd_offset(mm, start),
>> start), start), start);
>> for (;;) {
>> pmd_end = ((start + PGDIR_SIZE) & PGDIR_MASK) - 1;
>> if (pmd_end > end)
>> @@ -145,7 +145,7 @@ void flush_tlb_page(struct vm_area_struct *vma,
>> unsigned long vmaddr)
>> return;
>> }
>> mm = (vmaddr < TASK_SIZE)? vma->vm_mm: &init_mm;
>> - pmd = pmd_offset(pud_offset(pgd_offset(mm, vmaddr), vmaddr), vmaddr);
>> + pmd = pmd_offset(pud_offset(p4d_offset(pgd_offset(mm, vmaddr),
>> vmaddr), vmaddr), vmaddr);
>> if (!pmd_none(*pmd))
>> flush_hash_pages(mm->context.id, vmaddr, pmd_val(*pmd), 1);
>> }
>> diff --git a/arch/powerpc/mm/book3s64/hash_pgtable.c
>> b/arch/powerpc/mm/book3s64/hash_pgtable.c
>> index 64733b9cb20a..9cd15937e88a 100644
>> --- a/arch/powerpc/mm/book3s64/hash_pgtable.c
>> +++ b/arch/powerpc/mm/book3s64/hash_pgtable.c
>> @@ -148,6 +148,7 @@ void hash__vmemmap_remove_mapping(unsigned long start,
>> int hash__map_kernel_page(unsigned long ea, unsigned long pa,
>> pgprot_t prot)
>> {
>> pgd_t *pgdp;
>> + p4d_t *p4dp;
>> pud_t *pudp;
>> pmd_t *pmdp;
>> pte_t *ptep;
>> @@ -155,7 +156,8 @@ int hash__map_kernel_page(unsigned long ea,
>> unsigned long pa, pgprot_t prot)
>> BUILD_BUG_ON(TASK_SIZE_USER64 > H_PGTABLE_RANGE);
>> if (slab_is_available()) {
>> pgdp = pgd_offset_k(ea);
>> - pudp = pud_alloc(&init_mm, pgdp, ea);
>> + p4dp = p4d_offset(pgdp, ea);
>> + pudp = pud_alloc(&init_mm, p4dp, ea);
>> if (!pudp)
>> return -ENOMEM;
>> pmdp = pmd_alloc(&init_mm, pudp, ea);
>> diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c
>> b/arch/powerpc/mm/book3s64/radix_pgtable.c
>> index 974109bb85db..c02427eab084 100644
>> --- a/arch/powerpc/mm/book3s64/radix_pgtable.c
>> +++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
>> @@ -64,17 +64,24 @@ static int early_map_kernel_page(unsigned long
>> ea, unsigned long pa,
>> {
>> unsigned long pfn = pa >> PAGE_SHIFT;
>> pgd_t *pgdp;
>> + p4d_t *p4dp;
>> pud_t *pudp;
>> pmd_t *pmdp;
>> pte_t *ptep;
>>
>> pgdp = pgd_offset_k(ea);
>> if (pgd_none(*pgdp)) {
>> + p4dp = early_alloc_pgtable(PGD_TABLE_SIZE, nid,
>> + region_start, region_end);
>> + pgd_populate(&init_mm, pgdp, p4dp);
>> + }
>> + p4dp = p4d_offset(pgdp, ea);
>> + if (p4d_none(*p4dp)) {
>> pudp = early_alloc_pgtable(PUD_TABLE_SIZE, nid,
>> region_start, region_end);
>> - pgd_populate(&init_mm, pgdp, pudp);
>> + p4d_populate(&init_mm, p4dp, pudp);
>> }
>> - pudp = pud_offset(pgdp, ea);
>> + pudp = pud_offset(p4dp, ea);
>> if (map_page_size == PUD_SIZE) {
>> ptep = (pte_t *)pudp;
>> goto set_the_pte;
>> @@ -114,6 +121,7 @@ static int __map_kernel_page(unsigned long ea,
>> unsigned long pa,
>> {
>> unsigned long pfn = pa >> PAGE_SHIFT;
>> pgd_t *pgdp;
>> + p4d_t *p4dp;
>> pud_t *pudp;
>> pmd_t *pmdp;
>> pte_t *ptep;
>> @@ -136,7 +144,8 @@ static int __map_kernel_page(unsigned long ea,
>> unsigned long pa,
>> * boot.
>> */
>> pgdp = pgd_offset_k(ea);
>> - pudp = pud_alloc(&init_mm, pgdp, ea);
>> + p4dp = p4d_offset(pgdp, ea);
>> + pudp = pud_alloc(&init_mm, p4dp, ea);
>> if (!pudp)
>> return -ENOMEM;
>> if (map_page_size == PUD_SIZE) {
>> @@ -173,6 +182,7 @@ void radix__change_memory_range(unsigned long
>> start, unsigned long end,
>> {
>> unsigned long idx;
>> pgd_t *pgdp;
>> + p4d_t *p4dp;
>> pud_t *pudp;
>> pmd_t *pmdp;
>> pte_t *ptep;
>> @@ -185,7 +195,8 @@ void radix__change_memory_range(unsigned long
>> start, unsigned long end,
>>
>> for (idx = start; idx < end; idx += PAGE_SIZE) {
>> pgdp = pgd_offset_k(idx);
>> - pudp = pud_alloc(&init_mm, pgdp, idx);
>> + p4dp = p4d_offset(pgdp, idx);
>> + pudp = pud_alloc(&init_mm, p4dp, idx);
>> if (!pudp)
>> continue;
>> if (pud_is_leaf(*pudp)) {
>> diff --git a/arch/powerpc/mm/book3s64/subpage_prot.c
>> b/arch/powerpc/mm/book3s64/subpage_prot.c
>> index 2ef24a53f4c9..27daeed1a141 100644
>> --- a/arch/powerpc/mm/book3s64/subpage_prot.c
>> +++ b/arch/powerpc/mm/book3s64/subpage_prot.c
>> @@ -54,6 +54,7 @@ static void hpte_flush_range(struct mm_struct
>> *mm, unsigned long addr,
>> int npages)
>> {
>> pgd_t *pgd;
>> + p4d_t *p4d;
>> pud_t *pud;
>> pmd_t *pmd;
>> pte_t *pte;
>> @@ -62,7 +63,10 @@ static void hpte_flush_range(struct mm_struct
>> *mm, unsigned long addr,
>> pgd = pgd_offset(mm, addr);
>> if (pgd_none(*pgd))
>> return;
>> - pud = pud_offset(pgd, addr);
>> + p4d = p4d_offset(pgd, addr);
>> + if (p4d_none(*p4d))
>> + return;
>> + pud = pud_offset(p4d, addr);
>> if (pud_none(*pud))
>> return;
>> pmd = pmd_offset(pud, addr);
>> diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
>> index 73d4873fc7f8..43d463f20fc3 100644
>> --- a/arch/powerpc/mm/hugetlbpage.c
>> +++ b/arch/powerpc/mm/hugetlbpage.c
>> @@ -112,6 +112,7 @@ static int __hugepte_alloc(struct mm_struct
>> *mm, hugepd_t *hpdp,
>> pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr,
>> unsigned long sz)
>> {
>> pgd_t *pg;
>> + p4d_t *p4;
>> pud_t *pu;
>> pmd_t *pm;
>> hugepd_t *hpdp = NULL;
>> @@ -121,20 +122,21 @@ pte_t *huge_pte_alloc(struct mm_struct *mm,
>> unsigned long addr, unsigned long sz
>>
>> addr &= ~(sz-1);
>> pg = pgd_offset(mm, addr);
>> + p4 = p4d_offset(pg, addr);
>>
>> #ifdef CONFIG_PPC_BOOK3S_64
>> if (pshift == PGDIR_SHIFT)
>> /* 16GB huge page */
>> - return (pte_t *) pg;
>> + return (pte_t *) p4;
>> else if (pshift > PUD_SHIFT) {
>> /*
>> * We need to use hugepd table
>> */
>> ptl = &mm->page_table_lock;
>> - hpdp = (hugepd_t *)pg;
>> + hpdp = (hugepd_t *)p4;
>> } else {
>> pdshift = PUD_SHIFT;
>> - pu = pud_alloc(mm, pg, addr);
>> + pu = pud_alloc(mm, p4, addr);
>> if (!pu)
>> return NULL;
>> if (pshift == PUD_SHIFT)
>> @@ -159,10 +161,10 @@ pte_t *huge_pte_alloc(struct mm_struct *mm,
>> unsigned long addr, unsigned long sz
>> #else
>> if (pshift >= PGDIR_SHIFT) {
>> ptl = &mm->page_table_lock;
>> - hpdp = (hugepd_t *)pg;
>> + hpdp = (hugepd_t *)p4;
>> } else {
>> pdshift = PUD_SHIFT;
>> - pu = pud_alloc(mm, pg, addr);
>> + pu = pud_alloc(mm, p4, addr);
>> if (!pu)
>> return NULL;
>> if (pshift >= PUD_SHIFT) {
>> @@ -384,7 +386,7 @@ static void hugetlb_free_pmd_range(struct
>> mmu_gather *tlb, pud_t *pud,
>> mm_dec_nr_pmds(tlb->mm);
>> }
>>
>> -static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd,
>> +static void hugetlb_free_pud_range(struct mmu_gather *tlb, p4d_t *p4d,
>> unsigned long addr, unsigned long end,
>> unsigned long floor, unsigned long ceiling)
>> {
>> @@ -394,7 +396,7 @@ static void hugetlb_free_pud_range(struct
>> mmu_gather *tlb, pgd_t *pgd,
>>
>> start = addr;
>> do {
>> - pud = pud_offset(pgd, addr);
>> + pud = pud_offset(p4d, addr);
>> next = pud_addr_end(addr, end);
>> if (!is_hugepd(__hugepd(pud_val(*pud)))) {
>> if (pud_none_or_clear_bad(pud))
>> @@ -429,8 +431,8 @@ static void hugetlb_free_pud_range(struct
>> mmu_gather *tlb, pgd_t *pgd,
>> if (end - 1 > ceiling - 1)
>> return;
>>
>> - pud = pud_offset(pgd, start);
>> - pgd_clear(pgd);
>> + pud = pud_offset(p4d, start);
>> + p4d_clear(p4d);
>> pud_free_tlb(tlb, pud, start);
>> mm_dec_nr_puds(tlb->mm);
>> }
>> @@ -443,6 +445,7 @@ void hugetlb_free_pgd_range(struct mmu_gather *tlb,
>> unsigned long floor, unsigned long ceiling)
>> {
>> pgd_t *pgd;
>> + p4d_t *p4d;
>> unsigned long next;
>>
>> /*
>> @@ -465,10 +468,11 @@ void hugetlb_free_pgd_range(struct mmu_gather *tlb,
>> do {
>> next = pgd_addr_end(addr, end);
>> pgd = pgd_offset(tlb->mm, addr);
>> + p4d = p4d_offset(pgd, addr);
>> if (!is_hugepd(__hugepd(pgd_val(*pgd)))) {
>> - if (pgd_none_or_clear_bad(pgd))
>> + if (p4d_none_or_clear_bad(p4d))
>> continue;
>> - hugetlb_free_pud_range(tlb, pgd, addr, next, floor, ceiling);
>> + hugetlb_free_pud_range(tlb, p4d, addr, next, floor, ceiling);
>> } else {
>> unsigned long more;
>> /*
>> @@ -481,7 +485,7 @@ void hugetlb_free_pgd_range(struct mmu_gather *tlb,
>> if (more > next)
>> next = more;
>>
>> - free_hugepd_range(tlb, (hugepd_t *)pgd, PGDIR_SHIFT,
>> + free_hugepd_range(tlb, (hugepd_t *)p4d, PGDIR_SHIFT,
>> addr, next, floor, ceiling);
>> }
>> } while (addr = next, addr != end);
>> diff --git a/arch/powerpc/mm/kasan/kasan_init_32.c
>> b/arch/powerpc/mm/kasan/kasan_init_32.c
>> index 0e6ed4413eea..cac0452cbe1f 100644
>> --- a/arch/powerpc/mm/kasan/kasan_init_32.c
>> +++ b/arch/powerpc/mm/kasan/kasan_init_32.c
>> @@ -36,7 +36,7 @@ static int __ref
>> kasan_init_shadow_page_tables(unsigned long k_start, unsigned l
>> unsigned long k_cur, k_next;
>> pgprot_t prot = slab_is_available() ? kasan_prot_ro() : PAGE_KERNEL;
>>
>> - pmd = pmd_offset(pud_offset(pgd_offset_k(k_start), k_start), k_start);
>> + pmd = pmd_offset(pud_offset(p4d_offset(pgd_offset_k(k_start),
>> k_start), k_start), k_start);
>>
>> for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd++) {
>> pte_t *new;
>> @@ -94,7 +94,7 @@ static int __ref kasan_init_region(void *start,
>> size_t size)
>> block = memblock_alloc(k_end - k_start, PAGE_SIZE);
>>
>> for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
>> - pmd_t *pmd = pmd_offset(pud_offset(pgd_offset_k(k_cur), k_cur), k_cur);
>> + pmd_t *pmd =
>> pmd_offset(pud_offset(p4d_offset(pgd_offset_k(k_cur), k_cur),
>> k_cur), k_cur);
>> void *va = block ? block + k_cur - k_start : kasan_get_one_page();
>> pte_t pte = pfn_pte(PHYS_PFN(__pa(va)), PAGE_KERNEL);
>>
>> @@ -118,7 +118,7 @@ static void __init kasan_remap_early_shadow_ro(void)
>> kasan_populate_pte(kasan_early_shadow_pte, prot);
>>
>> for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
>> - pmd_t *pmd = pmd_offset(pud_offset(pgd_offset_k(k_cur), k_cur), k_cur);
>> + pmd_t *pmd =
>> pmd_offset(pud_offset(p4d_offset(pgd_offset_k(k_cur), k_cur),
>> k_cur), k_cur);
>> pte_t *ptep = pte_offset_kernel(pmd, k_cur);
>>
>> if ((pte_val(*ptep) & PTE_RPN_MASK) != pa)
>> @@ -205,7 +205,7 @@ void __init kasan_early_init(void)
>> unsigned long addr = KASAN_SHADOW_START;
>> unsigned long end = KASAN_SHADOW_END;
>> unsigned long next;
>> - pmd_t *pmd = pmd_offset(pud_offset(pgd_offset_k(addr), addr), addr);
>> + pmd_t *pmd = pmd_offset(pud_offset(p4d_offset(pgd_offset_k(addr),
>> addr), addr), addr);
>>
>> BUILD_BUG_ON(KASAN_SHADOW_START & ~PGDIR_MASK);
>>
>> diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
>> index 9488b63dfc87..ed2e24e493b9 100644
>> --- a/arch/powerpc/mm/mem.c
>> +++ b/arch/powerpc/mm/mem.c
>> @@ -68,8 +68,8 @@ EXPORT_SYMBOL(kmap_prot);
>>
>> static inline pte_t *virt_to_kpte(unsigned long vaddr)
>> {
>> - return pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr),
>> - vaddr), vaddr), vaddr);
>> + return
>> pte_offset_kernel(pmd_offset(pud_offset(p4d_offset(pgd_offset_k(vaddr),
>> + vaddr), vaddr), vaddr), vaddr);
>> }
>> #endif
>>
>> diff --git a/arch/powerpc/mm/nohash/40x.c b/arch/powerpc/mm/nohash/40x.c
>> index f348104eb461..7aaf7155e350 100644
>> --- a/arch/powerpc/mm/nohash/40x.c
>> +++ b/arch/powerpc/mm/nohash/40x.c
>> @@ -104,7 +104,7 @@ unsigned long __init mmu_mapin_ram(unsigned
>> long base, unsigned long top)
>> pmd_t *pmdp;
>> unsigned long val = p | _PMD_SIZE_16M | _PAGE_EXEC | _PAGE_HWWRITE;
>>
>> - pmdp = pmd_offset(pud_offset(pgd_offset_k(v), v), v);
>> + pmdp = pmd_offset(pud_offset(p4d_offset(pgd_offset_k(v), v), v), v);
>> *pmdp++ = __pmd(val);
>> *pmdp++ = __pmd(val);
>> *pmdp++ = __pmd(val);
>> @@ -119,7 +119,7 @@ unsigned long __init mmu_mapin_ram(unsigned
>> long base, unsigned long top)
>> pmd_t *pmdp;
>> unsigned long val = p | _PMD_SIZE_4M | _PAGE_EXEC | _PAGE_HWWRITE;
>>
>> - pmdp = pmd_offset(pud_offset(pgd_offset_k(v), v), v);
>> + pmdp = pmd_offset(pud_offset(p4d_offset(pgd_offset_k(v), v), v), v);
>> *pmdp = __pmd(val);
>>
>> v += LARGE_PAGE_SIZE_4M;
>> diff --git a/arch/powerpc/mm/nohash/book3e_pgtable.c
>> b/arch/powerpc/mm/nohash/book3e_pgtable.c
>> index 4637fdd469cf..a62d59a928be 100644
>> --- a/arch/powerpc/mm/nohash/book3e_pgtable.c
>> +++ b/arch/powerpc/mm/nohash/book3e_pgtable.c
>> @@ -73,6 +73,7 @@ static void __init *early_alloc_pgtable(unsigned
>> long size)
>> int __ref map_kernel_page(unsigned long ea, unsigned long pa,
>> pgprot_t prot)
>> {
>> pgd_t *pgdp;
>> + p4d_t *p4dp;
>> pud_t *pudp;
>> pmd_t *pmdp;
>> pte_t *ptep;
>> @@ -80,7 +81,10 @@ int __ref map_kernel_page(unsigned long ea,
>> unsigned long pa, pgprot_t prot)
>> BUILD_BUG_ON(TASK_SIZE_USER64 > PGTABLE_RANGE);
>> if (slab_is_available()) {
>> pgdp = pgd_offset_k(ea);
>> - pudp = pud_alloc(&init_mm, pgdp, ea);
>> + p4dp = p4d_alloc(&init_mm, pgdp, ea);
>> + if (!p4dp)
>> + return -ENOMEM;
>> + pudp = pud_alloc(&init_mm, p4dp, ea);
>> if (!pudp)
>> return -ENOMEM;
>> pmdp = pmd_alloc(&init_mm, pudp, ea);
>> @@ -91,13 +95,16 @@ int __ref map_kernel_page(unsigned long ea,
>> unsigned long pa, pgprot_t prot)
>> return -ENOMEM;
>> } else {
>> pgdp = pgd_offset_k(ea);
>> -#ifndef __PAGETABLE_PUD_FOLDED
>> if (pgd_none(*pgdp)) {
>> pudp = early_alloc_pgtable(PUD_TABLE_SIZE);
>> pgd_populate(&init_mm, pgdp, pudp);
>> }
>> -#endif /* !__PAGETABLE_PUD_FOLDED */
>> - pudp = pud_offset(pgdp, ea);
>> + p4dp = p4d_offset(pgdp, ea);
>> + if (p4d_none(*p4dp)) {
>> + pmdp = early_alloc_pgtable(PMD_TABLE_SIZE);
>> + p4d_populate(&init_mm, p4dp, pmdp);
>> + }
>> + pudp = pud_offset(p4dp, ea);
>> if (pud_none(*pudp)) {
>> pmdp = early_alloc_pgtable(PMD_TABLE_SIZE);
>> pud_populate(&init_mm, pudp, pmdp);
>> diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
>> index e3759b69f81b..dca6a72da26a 100644
>> --- a/arch/powerpc/mm/pgtable.c
>> +++ b/arch/powerpc/mm/pgtable.c
>> @@ -265,6 +265,7 @@ int huge_ptep_set_access_flags(struct
>> vm_area_struct *vma,
>> void assert_pte_locked(struct mm_struct *mm, unsigned long addr)
>> {
>> pgd_t *pgd;
>> + p4d_t *p4d;
>> pud_t *pud;
>> pmd_t *pmd;
>>
>> @@ -272,7 +273,9 @@ void assert_pte_locked(struct mm_struct *mm,
>> unsigned long addr)
>> return;
>> pgd = mm->pgd + pgd_index(addr);
>> BUG_ON(pgd_none(*pgd));
>> - pud = pud_offset(pgd, addr);
>> + p4d = p4d_offset(pgd, addr);
>> + BUG_ON(p4d_none(*p4d));
>> + pud = pud_offset(p4d, addr);
>> BUG_ON(pud_none(*pud));
>> pmd = pmd_offset(pud, addr);
>> /*
>> @@ -313,6 +316,7 @@ pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
>> bool *is_thp, unsigned *hpage_shift)
>> {
>> pgd_t pgd, *pgdp;
>> + p4d_t p4d, *p4dp;
>> pud_t pud, *pudp;
>> pmd_t pmd, *pmdp;
>> pte_t *ret_pte;
>> @@ -346,13 +350,30 @@ pte_t *__find_linux_pte(pgd_t *pgdir,
>> unsigned long ea,
>> goto out_huge;
>> }
>>
>> + pdshift = P4D_SHIFT;
>> + p4dp = p4d_offset(&pgd, ea);
>> + p4d = READ_ONCE(*p4dp);
>> +
>> + if (p4d_none(p4d))
>> + return NULL;
>> +
>> + if (p4d_is_leaf(p4d)) {
>> + ret_pte = (pte_t *)p4dp;
>> + goto out;
>> + }
>> +
>> + if (is_hugepd(__hugepd(p4d_val(p4d)))) {
>> + hpdp = (hugepd_t *)&p4d;
>> + goto out_huge;
>> + }
>> +
>> /*
>> * Even if we end up with an unmap, the pgtable will not
>> * be freed, because we do an rcu free and here we are
>> * irq disabled
>> */
>> pdshift = PUD_SHIFT;
>> - pudp = pud_offset(&pgd, ea);
>> + pudp = pud_offset(&p4d, ea);
>> pud = READ_ONCE(*pudp);
>>
>> if (pud_none(pud))
>> diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
>> index 73b84166d06a..50d97127a801 100644
>> --- a/arch/powerpc/mm/pgtable_32.c
>> +++ b/arch/powerpc/mm/pgtable_32.c
>> @@ -63,7 +63,7 @@ int __ref map_kernel_page(unsigned long va,
>> phys_addr_t pa, pgprot_t prot)
>> int err = -ENOMEM;
>>
>> /* Use upper 10 bits of VA to index the first level map */
>> - pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va);
>> + pd = pmd_offset(pud_offset(p4d_offset(pgd_offset_k(va), va), va), va);
>> /* Use middle 10 bits of VA to index the second-level map */
>> if (likely(slab_is_available()))
>> pg = pte_alloc_kernel(pd, va);
>> @@ -130,6 +130,7 @@ static int
>> get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep,
>> pmd_t **pmdp)
>> {
>> pgd_t *pgd;
>> + p4d_t *p4d;
>> pud_t *pud;
>> pmd_t *pmd;
>> pte_t *pte;
>> @@ -137,17 +138,20 @@ get_pteptr(struct mm_struct *mm, unsigned
>> long addr, pte_t **ptep, pmd_t **pmdp)
>>
>> pgd = pgd_offset(mm, addr & PAGE_MASK);
>> if (pgd) {
>> - pud = pud_offset(pgd, addr & PAGE_MASK);
>> - if (pud && pud_present(*pud)) {
>> - pmd = pmd_offset(pud, addr & PAGE_MASK);
>> - if (pmd_present(*pmd)) {
>> - pte = pte_offset_map(pmd, addr & PAGE_MASK);
>> - if (pte) {
>> - retval = 1;
>> - *ptep = pte;
>> - if (pmdp)
>> - *pmdp = pmd;
>> - /* XXX caller needs to do pte_unmap, yuck */
>> + p4d = p4d_offset(pgd, addr & PAGE_MASK);
>> + if (p4d && p4d_present(*p4d)) {
>> + pud = pud_offset(p4d, addr & PAGE_MASK);
>> + if (pud && pud_present(*pud)) {
>> + pmd = pmd_offset(pud, addr & PAGE_MASK);
>> + if (pmd_present(*pmd)) {
>> + pte = pte_offset_map(pmd, addr & PAGE_MASK);
>> + if (pte) {
>> + retval = 1;
>> + *ptep = pte;
>> + if (pmdp)
>> + *pmdp = pmd;
>> + /* XXX caller needs to do pte_unmap, yuck */
>> + }
>> }
>> }
>> }
>> diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
>> index e78832dce7bb..1f86a88fd4bb 100644
>> --- a/arch/powerpc/mm/pgtable_64.c
>> +++ b/arch/powerpc/mm/pgtable_64.c
>> @@ -101,13 +101,13 @@ EXPORT_SYMBOL(__pte_frag_size_shift);
>>
>> #ifndef __PAGETABLE_PUD_FOLDED
>> /* 4 level page table */
>> -struct page *pgd_page(pgd_t pgd)
>> +struct page *p4d_page(p4d_t p4d)
>> {
>> - if (pgd_is_leaf(pgd)) {
>> - VM_WARN_ON(!pgd_huge(pgd));
>> - return pte_page(pgd_pte(pgd));
>> + if (p4d_is_leaf(p4d)) {
>> + VM_WARN_ON(!p4d_huge(p4d));
>> + return pte_page(p4d_pte(p4d));
>> }
>> - return virt_to_page(pgd_page_vaddr(pgd));
>> + return virt_to_page(p4d_page_vaddr(p4d));
>> }
>> #endif
>>
>> diff --git a/arch/powerpc/mm/ptdump/hashpagetable.c
>> b/arch/powerpc/mm/ptdump/hashpagetable.c
>> index a07278027c6f..ac360ad865a8 100644
>> --- a/arch/powerpc/mm/ptdump/hashpagetable.c
>> +++ b/arch/powerpc/mm/ptdump/hashpagetable.c
>> @@ -417,9 +417,9 @@ static void walk_pmd(struct pg_state *st, pud_t
>> *pud, unsigned long start)
>> }
>> }
>>
>> -static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start)
>> +static void walk_pud(struct pg_state *st, p4d_t *p4d, unsigned long start)
>> {
>> - pud_t *pud = pud_offset(pgd, 0);
>> + pud_t *pud = pud_offset(p4d, 0);
>> unsigned long addr;
>> unsigned int i;
>>
>> @@ -431,6 +431,20 @@ static void walk_pud(struct pg_state *st,
>> pgd_t *pgd, unsigned long start)
>> }
>> }
>>
>> +static void walk_p4d(struct pg_state *st, pgd_t *pgd, unsigned long start)
>> +{
>> + p4d_t *p4d = p4d_offset(pgd, 0);
>> + unsigned long addr;
>> + unsigned int i;
>> +
>> + for (i = 0; i < PTRS_PER_P4D; i++, p4d++) {
>> + addr = start + i * P4D_SIZE;
>> + if (!p4d_none(*p4d))
>> + /* p4d exists */
>> + walk_pud(st, p4d, addr);
>> + }
>> +}
>> +
>> static void walk_pagetables(struct pg_state *st)
>> {
>> pgd_t *pgd = pgd_offset_k(0UL);
>> @@ -445,7 +459,7 @@ static void walk_pagetables(struct pg_state *st)
>> addr = KERN_VIRT_START + i * PGDIR_SIZE;
>> if (!pgd_none(*pgd))
>> /* pgd exists */
>> - walk_pud(st, pgd, addr);
>> + walk_p4d(st, pgd, addr);
>> }
>> }
>>
>> diff --git a/arch/powerpc/mm/ptdump/ptdump.c
>> b/arch/powerpc/mm/ptdump/ptdump.c
>> index 2f9ddc29c535..5c2f3b916ac8 100644
>> --- a/arch/powerpc/mm/ptdump/ptdump.c
>> +++ b/arch/powerpc/mm/ptdump/ptdump.c
>> @@ -273,9 +273,9 @@ static void walk_pmd(struct pg_state *st, pud_t
>> *pud, unsigned long start)
>> }
>> }
>>
>> -static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start)
>> +static void walk_pud(struct pg_state *st, p4d_t *p4d, unsigned long start)
>> {
>> - pud_t *pud = pud_offset(pgd, 0);
>> + pud_t *pud = pud_offset(p4d, 0);
>> unsigned long addr;
>> unsigned int i;
>>
>> @@ -289,6 +289,22 @@ static void walk_pud(struct pg_state *st,
>> pgd_t *pgd, unsigned long start)
>> }
>> }
>>
>> +static void walk_p4d(struct pg_state *st, pgd_t *pgd, unsigned long start)
>> +{
>> + p4d_t *p4d = p4d_offset(pgd, 0);
>> + unsigned long addr;
>> + unsigned int i;
>> +
>> + for (i = 0; i < PTRS_PER_P4D; i++, p4d++) {
>> + addr = start + i * P4D_SIZE;
>> + if (!p4d_none(*p4d) && !p4d_is_leaf(*p4d))
>> + /* p4d exists */
>> + walk_pud(st, p4d, addr);
>> + else
>> + note_page(st, addr, 2, p4d_val(*p4d));
>> + }
>> +}
>> +
>> static void walk_pagetables(struct pg_state *st)
>> {
>> unsigned int i;
>> @@ -302,7 +318,7 @@ static void walk_pagetables(struct pg_state *st)
>> for (i = pgd_index(addr); i < PTRS_PER_PGD; i++, pgd++, addr +=
>> PGDIR_SIZE) {
>> if (!pgd_none(*pgd) && !pgd_is_leaf(*pgd))
>> /* pgd exists */
>> - walk_pud(st, pgd, addr);
>> + walk_p4d(st, pgd, addr);
>> else
>> note_page(st, addr, 1, pgd_val(*pgd));
>> }
>> diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
>> index a7056049709e..dd36e10efa65 100644
>> --- a/arch/powerpc/xmon/xmon.c
>> +++ b/arch/powerpc/xmon/xmon.c
>> @@ -3128,6 +3128,7 @@ static void show_pte(unsigned long addr)
>> struct task_struct *tsk = NULL;
>> struct mm_struct *mm;
>> pgd_t *pgdp, *pgdir;
>> + p4d_t *p4dp;
>> pud_t *pudp;
>> pmd_t *pmdp;
>> pte_t *ptep;
>> @@ -3172,7 +3173,21 @@ static void show_pte(unsigned long addr)
>> }
>> printf("pgdp @ 0x%px = 0x%016lx\n", pgdp, pgd_val(*pgdp));
>>
>> - pudp = pud_offset(pgdp, addr);
>> + p4dp = p4d_offset(pgdp, addr);
>> +
>> + if (p4d_none(*p4dp)) {
>> + printf("No valid P4D\n");
>> + return;
>> + }
>> +
>> + if (p4d_is_leaf(*p4dp)) {
>> + format_pte(p4dp, p4d_val(*p4dp));
>> + return;
>> + }
>> +
>> + printf("p4dp @ 0x%px = 0x%016lx\n", p4dp, p4d_val(*p4dp));
>> +
>> + pudp = pud_offset(p4dp, addr);
>>
>> if (pud_none(*pudp)) {
>> printf("No valid PUD\n");
>> --
>> 2.24.0
>>
>
> --
> Sincerely yours,
> Mike.