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

Mike Rapoport
2020-01-02T08:11:09Z

Any updates on this?

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.