From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8D1F6C433DF for ; Sat, 16 May 2020 17:20:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 54E61206D4 for ; Sat, 16 May 2020 17:20:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589649642; bh=IeA0raojPlenut/DBeELqvxBTfUPBQNLD0csXWioRdc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=icvmW1RGFwYipzQe+davykW3dCl3fwVHIU3H2VQO6xFj6xX4/HllfRCGKSK5pVuUN M91NC6RKFpX/BluFDueZiqkOj7rHnrVpj4DS43daMZVrzH6b8XaHy4EmlRDlsFwV/U JYDpSXzYKK/kHdUpVK8EkPPObR8b0PqK42FEszDI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726528AbgEPRUk (ORCPT ); Sat, 16 May 2020 13:20:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:47832 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726276AbgEPRUj (ORCPT ); Sat, 16 May 2020 13:20:39 -0400 Received: from kernel.org (unknown [77.124.237.152]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B1B2C2065C; Sat, 16 May 2020 17:20:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589649636; bh=IeA0raojPlenut/DBeELqvxBTfUPBQNLD0csXWioRdc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mz+/82TnbME6MlnCBfzsUOaa/kaMz5TR1zUyfpDbt8BKxlL3IqD0HD1zOKZH2cA9f WC3ywud25HOyCHsaBpFeqJQpncrNn5YrWhGvhqxyf4aHKZuOoUwKjXyGxPRtjhW4k+ inpQi8O88x+nVu6LFQ/DYfDFiCHUwS4EqVIbMplE= Date: Sat, 16 May 2020 20:20:15 +0300 From: Mike Rapoport To: Andrew Morton Cc: Arnd Bergmann , Benjamin Herrenschmidt , Brian Cain , Catalin Marinas , Christophe Leroy , Fenghua Yu , Geert Uytterhoeven , Guan Xuetao , James Morse , Jonas Bonn , Julien Thierry , Ley Foon Tan , Marc Zyngier , Michael Ellerman , Paul Mackerras , Rich Felker , Russell King , Stafford Horne , Stefan Kristiansson , Suzuki K Poulose , Tony Luck , Will Deacon , Yoshinori Sato , kvmarm@lists.cs.columbia.edu, kvm-ppc@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-sh@vger.kernel.org, nios2-dev@lists.rocketboards.org, openrisc@lists.librecores.org, uclinux-h8-devel@lists.sourceforge.jp, Mike Rapoport Subject: Re: [PATCH v4 03/14] arm64: add support for folded p4d page tables Message-ID: <20200516172015.GA1118872@kernel.org> References: <20200414153455.21744-1-rppt@kernel.org> <20200414153455.21744-4-rppt@kernel.org> <20200515114012.49f45aa01efb7d8b918bc0f5@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200515114012.49f45aa01efb7d8b918bc0f5@linux-foundation.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 15, 2020 at 11:40:12AM -0700, Andrew Morton wrote: > On Tue, 14 Apr 2020 18:34:44 +0300 Mike Rapoport wrote: > > > Implement primitives necessary for the 4th level folding, add walks of p4d > > level where appropriate, replace 5level-fixup.h with pgtable-nop4d.h and > > remove __ARCH_USE_5LEVEL_HACK. > > This needed some rework due to arm changes in linux-next. Please check > my handiwork and test it once I've merged this into linux-next? Looks ok to me. It passed defconfig and a couple of randconfig builds and qemu-system-aarch64 boots find with this. > Rejects were > > --- arch/arm64/include/asm/pgtable.h~arm64-add-support-for-folded-p4d-page-tables > +++ arch/arm64/include/asm/pgtable.h > @@ -596,49 +604,50 @@ static inline phys_addr_t pud_page_paddr > > #define pud_ERROR(pud) __pud_error(__FILE__, __LINE__, pud_val(pud)) > > -#define pgd_none(pgd) (!pgd_val(pgd)) > -#define pgd_bad(pgd) (!(pgd_val(pgd) & 2)) > -#define pgd_present(pgd) (pgd_val(pgd)) > +#define p4d_none(p4d) (!p4d_val(p4d)) > +#define p4d_bad(p4d) (!(p4d_val(p4d) & 2)) > +#define p4d_present(p4d) (p4d_val(p4d)) > > -static inline void set_pgd(pgd_t *pgdp, pgd_t pgd) > +static inline void set_p4d(p4d_t *p4dp, p4d_t p4d) > { > - if (in_swapper_pgdir(pgdp)) { > - set_swapper_pgd(pgdp, pgd); > + if (in_swapper_pgdir(p4dp)) { > + set_swapper_pgd((pgd_t *)p4dp, __pgd(p4d_val(p4d))); > return; > } > > - WRITE_ONCE(*pgdp, pgd); > + WRITE_ONCE(*p4dp, p4d); > dsb(ishst); > isb(); > } > > -static inline void pgd_clear(pgd_t *pgdp) > +static inline void p4d_clear(p4d_t *p4dp) > { > - set_pgd(pgdp, __pgd(0)); > + set_p4d(p4dp, __p4d(0)); > } > > -static inline phys_addr_t pgd_page_paddr(pgd_t pgd) > +static inline phys_addr_t p4d_page_paddr(p4d_t p4d) > { > - return __pgd_to_phys(pgd); > + return __p4d_to_phys(p4d); > } > > /* Find an entry in the frst-level page table. */ > #define pud_index(addr) (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1)) > > -#define pud_offset_phys(dir, addr) (pgd_page_paddr(READ_ONCE(*(dir))) + pud_index(addr) * sizeof(pud_t)) > +#define pud_offset_phys(dir, addr) (p4d_page_paddr(READ_ONCE(*(dir))) + pud_index(addr) * sizeof(pud_t)) > #define pud_offset(dir, addr) ((pud_t *)__va(pud_offset_phys((dir), (addr)))) > > #define pud_set_fixmap(addr) ((pud_t *)set_fixmap_offset(FIX_PUD, addr)) > -#define pud_set_fixmap_offset(pgd, addr) pud_set_fixmap(pud_offset_phys(pgd, addr)) > +#define pud_set_fixmap_offset(p4d, addr) pud_set_fixmap(pud_offset_phys(p4d, addr)) > #define pud_clear_fixmap() clear_fixmap(FIX_PUD) > > -#define pgd_page(pgd) pfn_to_page(__phys_to_pfn(__pgd_to_phys(pgd))) > +#define p4d_page(p4d) pfn_to_page(__phys_to_pfn(__p4d_to_phys(p4d))) > > /* use ONLY for statically allocated translation tables */ > #define pud_offset_kimg(dir,addr) ((pud_t *)__phys_to_kimg(pud_offset_phys((dir), (addr)))) > > #else > > +#define p4d_page_paddr(p4d) ({ BUILD_BUG(); 0;}) > #define pgd_page_paddr(pgd) ({ BUILD_BUG(); 0;}) > > /* Match pud_offset folding in */ > > > > and > > --- arch/arm64/kvm/mmu.c~arm64-add-support-for-folded-p4d-page-tables > +++ arch/arm64/kvm/mmu.c > @@ -469,7 +517,7 @@ static void stage2_flush_memslot(struct > do { > next = stage2_pgd_addr_end(kvm, addr, end); > if (!stage2_pgd_none(kvm, *pgd)) > - stage2_flush_puds(kvm, pgd, addr, next); > + stage2_flush_p4ds(kvm, pgd, addr, next); > } while (pgd++, addr = next, addr != end); > } > > > > Result: > > From: Mike Rapoport > Subject: arm64: add support for folded p4d page tables > > Implement primitives necessary for the 4th level folding, add walks of p4d > level where appropriate, replace 5level-fixup.h with pgtable-nop4d.h and > remove __ARCH_USE_5LEVEL_HACK. > > Link: http://lkml.kernel.org/r/20200414153455.21744-4-rppt@kernel.org > Signed-off-by: Mike Rapoport > Cc: Arnd Bergmann > Cc: Benjamin Herrenschmidt > Cc: Brian Cain > Cc: Catalin Marinas > Cc: Christophe Leroy > Cc: Fenghua Yu > Cc: Geert Uytterhoeven > Cc: Guan Xuetao > Cc: James Morse > Cc: Jonas Bonn > Cc: Julien Thierry > Cc: Ley Foon Tan > Cc: Marc Zyngier > Cc: Michael Ellerman > Cc: Paul Mackerras > Cc: Rich Felker > Cc: Russell King > Cc: Stafford Horne > Cc: Stefan Kristiansson > Cc: Suzuki K Poulose > Cc: Tony Luck > Cc: Will Deacon > Cc: Yoshinori Sato > Signed-off-by: Andrew Morton > --- > > arch/arm64/include/asm/kvm_mmu.h | 10 - > arch/arm64/include/asm/pgalloc.h | 10 - > arch/arm64/include/asm/pgtable-types.h | 5 > arch/arm64/include/asm/pgtable.h | 37 ++- > arch/arm64/include/asm/stage2_pgtable.h | 48 +++-- > arch/arm64/kernel/hibernate.c | 44 +++- > arch/arm64/kvm/mmu.c | 209 ++++++++++++++++++---- > arch/arm64/mm/fault.c | 9 > arch/arm64/mm/hugetlbpage.c | 15 + > arch/arm64/mm/kasan_init.c | 26 ++ > arch/arm64/mm/mmu.c | 52 +++-- > arch/arm64/mm/pageattr.c | 7 > 12 files changed, 368 insertions(+), 104 deletions(-) > > --- a/arch/arm64/include/asm/kvm_mmu.h~arm64-add-support-for-folded-p4d-page-tables > +++ a/arch/arm64/include/asm/kvm_mmu.h > @@ -172,8 +172,8 @@ void kvm_clear_hyp_idmap(void); > __pmd(__phys_to_pmd_val(__pa(ptep)) | PMD_TYPE_TABLE) > #define kvm_mk_pud(pmdp) \ > __pud(__phys_to_pud_val(__pa(pmdp)) | PMD_TYPE_TABLE) > -#define kvm_mk_pgd(pudp) \ > - __pgd(__phys_to_pgd_val(__pa(pudp)) | PUD_TYPE_TABLE) > +#define kvm_mk_p4d(pmdp) \ > + __p4d(__phys_to_p4d_val(__pa(pmdp)) | PUD_TYPE_TABLE) > > #define kvm_set_pud(pudp, pud) set_pud(pudp, pud) > > @@ -299,6 +299,12 @@ static inline bool kvm_s2pud_young(pud_t > #define hyp_pud_table_empty(pudp) kvm_page_empty(pudp) > #endif > > +#ifdef __PAGETABLE_P4D_FOLDED > +#define hyp_p4d_table_empty(p4dp) (0) > +#else > +#define hyp_p4d_table_empty(p4dp) kvm_page_empty(p4dp) > +#endif > + > struct kvm; > > #define kvm_flush_dcache_to_poc(a,l) __flush_dcache_area((a), (l)) > --- a/arch/arm64/include/asm/pgalloc.h~arm64-add-support-for-folded-p4d-page-tables > +++ a/arch/arm64/include/asm/pgalloc.h > @@ -73,17 +73,17 @@ static inline void pud_free(struct mm_st > free_page((unsigned long)pudp); > } > > -static inline void __pgd_populate(pgd_t *pgdp, phys_addr_t pudp, pgdval_t prot) > +static inline void __p4d_populate(p4d_t *p4dp, phys_addr_t pudp, p4dval_t prot) > { > - set_pgd(pgdp, __pgd(__phys_to_pgd_val(pudp) | prot)); > + set_p4d(p4dp, __p4d(__phys_to_p4d_val(pudp) | prot)); > } > > -static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgdp, pud_t *pudp) > +static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4dp, pud_t *pudp) > { > - __pgd_populate(pgdp, __pa(pudp), PUD_TYPE_TABLE); > + __p4d_populate(p4dp, __pa(pudp), PUD_TYPE_TABLE); > } > #else > -static inline void __pgd_populate(pgd_t *pgdp, phys_addr_t pudp, pgdval_t prot) > +static inline void __p4d_populate(p4d_t *p4dp, phys_addr_t pudp, p4dval_t prot) > { > BUILD_BUG(); > } > --- a/arch/arm64/include/asm/pgtable.h~arm64-add-support-for-folded-p4d-page-tables > +++ a/arch/arm64/include/asm/pgtable.h > @@ -298,6 +298,11 @@ static inline pte_t pgd_pte(pgd_t pgd) > return __pte(pgd_val(pgd)); > } > > +static inline pte_t p4d_pte(p4d_t p4d) > +{ > + return __pte(p4d_val(p4d)); > +} > + > static inline pte_t pud_pte(pud_t pud) > { > return __pte(pud_val(pud)); > @@ -401,6 +406,9 @@ static inline pmd_t pmd_mkdevmap(pmd_t p > > #define set_pmd_at(mm, addr, pmdp, pmd) set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd)) > > +#define __p4d_to_phys(p4d) __pte_to_phys(p4d_pte(p4d)) > +#define __phys_to_p4d_val(phys) __phys_to_pte_val(phys) > + > #define __pgd_to_phys(pgd) __pte_to_phys(pgd_pte(pgd)) > #define __phys_to_pgd_val(phys) __phys_to_pte_val(phys) > > @@ -592,49 +600,50 @@ static inline phys_addr_t pud_page_paddr > > #define pud_ERROR(pud) __pud_error(__FILE__, __LINE__, pud_val(pud)) > > -#define pgd_none(pgd) (!pgd_val(pgd)) > -#define pgd_bad(pgd) (!(pgd_val(pgd) & 2)) > -#define pgd_present(pgd) (pgd_val(pgd)) > +#define p4d_none(p4d) (!p4d_val(p4d)) > +#define p4d_bad(p4d) (!(p4d_val(p4d) & 2)) > +#define p4d_present(p4d) (p4d_val(p4d)) > > -static inline void set_pgd(pgd_t *pgdp, pgd_t pgd) > +static inline void set_p4d(p4d_t *p4dp, p4d_t p4d) > { > - if (in_swapper_pgdir(pgdp)) { > - set_swapper_pgd(pgdp, pgd); > + if (in_swapper_pgdir(p4dp)) { > + set_swapper_pgd((pgd_t *)p4dp, __pgd(p4d_val(p4d))); > return; > } > > - WRITE_ONCE(*pgdp, pgd); > + WRITE_ONCE(*p4dp, p4d); > dsb(ishst); > isb(); > } > > -static inline void pgd_clear(pgd_t *pgdp) > +static inline void p4d_clear(p4d_t *p4dp) > { > - set_pgd(pgdp, __pgd(0)); > + set_p4d(p4dp, __p4d(0)); > } > > -static inline phys_addr_t pgd_page_paddr(pgd_t pgd) > +static inline phys_addr_t p4d_page_paddr(p4d_t p4d) > { > - return __pgd_to_phys(pgd); > + return __p4d_to_phys(p4d); > } > > /* Find an entry in the frst-level page table. */ > #define pud_index(addr) (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1)) > > -#define pud_offset_phys(dir, addr) (pgd_page_paddr(READ_ONCE(*(dir))) + pud_index(addr) * sizeof(pud_t)) > +#define pud_offset_phys(dir, addr) (p4d_page_paddr(READ_ONCE(*(dir))) + pud_index(addr) * sizeof(pud_t)) > #define pud_offset(dir, addr) ((pud_t *)__va(pud_offset_phys((dir), (addr)))) > > #define pud_set_fixmap(addr) ((pud_t *)set_fixmap_offset(FIX_PUD, addr)) > -#define pud_set_fixmap_offset(pgd, addr) pud_set_fixmap(pud_offset_phys(pgd, addr)) > +#define pud_set_fixmap_offset(p4d, addr) pud_set_fixmap(pud_offset_phys(p4d, addr)) > #define pud_clear_fixmap() clear_fixmap(FIX_PUD) > > -#define pgd_page(pgd) phys_to_page(__pgd_to_phys(pgd)) > +#define p4d_page(p4d) pfn_to_page(__phys_to_pfn(__p4d_to_phys(p4d))) > > /* use ONLY for statically allocated translation tables */ > #define pud_offset_kimg(dir,addr) ((pud_t *)__phys_to_kimg(pud_offset_phys((dir), (addr)))) > > #else > > +#define p4d_page_paddr(p4d) ({ BUILD_BUG(); 0;}) > #define pgd_page_paddr(pgd) ({ BUILD_BUG(); 0;}) > > /* Match pud_offset folding in */ > --- a/arch/arm64/include/asm/pgtable-types.h~arm64-add-support-for-folded-p4d-page-tables > +++ a/arch/arm64/include/asm/pgtable-types.h > @@ -14,6 +14,7 @@ > typedef u64 pteval_t; > typedef u64 pmdval_t; > typedef u64 pudval_t; > +typedef u64 p4dval_t; > typedef u64 pgdval_t; > > /* > @@ -44,13 +45,11 @@ typedef struct { pteval_t pgprot; } pgpr > #define __pgprot(x) ((pgprot_t) { (x) } ) > > #if CONFIG_PGTABLE_LEVELS == 2 > -#define __ARCH_USE_5LEVEL_HACK > #include > #elif CONFIG_PGTABLE_LEVELS == 3 > -#define __ARCH_USE_5LEVEL_HACK > #include > #elif CONFIG_PGTABLE_LEVELS == 4 > -#include > +#include > #endif > > #endif /* __ASM_PGTABLE_TYPES_H */ > --- a/arch/arm64/include/asm/stage2_pgtable.h~arm64-add-support-for-folded-p4d-page-tables > +++ a/arch/arm64/include/asm/stage2_pgtable.h > @@ -68,41 +68,67 @@ static inline bool kvm_stage2_has_pud(st > #define S2_PUD_SIZE (1UL << S2_PUD_SHIFT) > #define S2_PUD_MASK (~(S2_PUD_SIZE - 1)) > > -static inline bool stage2_pgd_none(struct kvm *kvm, pgd_t pgd) > +#define stage2_pgd_none(kvm, pgd) pgd_none(pgd) > +#define stage2_pgd_clear(kvm, pgd) pgd_clear(pgd) > +#define stage2_pgd_present(kvm, pgd) pgd_present(pgd) > +#define stage2_pgd_populate(kvm, pgd, p4d) pgd_populate(NULL, pgd, p4d) > + > +static inline p4d_t *stage2_p4d_offset(struct kvm *kvm, > + pgd_t *pgd, unsigned long address) > +{ > + return p4d_offset(pgd, address); > +} > + > +static inline void stage2_p4d_free(struct kvm *kvm, p4d_t *p4d) > +{ > +} > + > +static inline bool stage2_p4d_table_empty(struct kvm *kvm, p4d_t *p4dp) > +{ > + return false; > +} > + > +static inline phys_addr_t stage2_p4d_addr_end(struct kvm *kvm, > + phys_addr_t addr, phys_addr_t end) > +{ > + return end; > +} > + > +static inline bool stage2_p4d_none(struct kvm *kvm, p4d_t p4d) > { > if (kvm_stage2_has_pud(kvm)) > - return pgd_none(pgd); > + return p4d_none(p4d); > else > return 0; > } > > -static inline void stage2_pgd_clear(struct kvm *kvm, pgd_t *pgdp) > +static inline void stage2_p4d_clear(struct kvm *kvm, p4d_t *p4dp) > { > if (kvm_stage2_has_pud(kvm)) > - pgd_clear(pgdp); > + p4d_clear(p4dp); > } > > -static inline bool stage2_pgd_present(struct kvm *kvm, pgd_t pgd) > +static inline bool stage2_p4d_present(struct kvm *kvm, p4d_t p4d) > { > if (kvm_stage2_has_pud(kvm)) > - return pgd_present(pgd); > + return p4d_present(p4d); > else > return 1; > } > > -static inline void stage2_pgd_populate(struct kvm *kvm, pgd_t *pgd, pud_t *pud) > +static inline void stage2_p4d_populate(struct kvm *kvm, p4d_t *p4d, pud_t *pud) > { > if (kvm_stage2_has_pud(kvm)) > - pgd_populate(NULL, pgd, pud); > + p4d_populate(NULL, p4d, pud); > } > > static inline pud_t *stage2_pud_offset(struct kvm *kvm, > - pgd_t *pgd, unsigned long address) > + p4d_t *p4d, unsigned long address) > { > if (kvm_stage2_has_pud(kvm)) > - return pud_offset(pgd, address); > + return pud_offset(p4d, address); > else > - return (pud_t *)pgd; > + return (pud_t *)p4d; > } > > static inline void stage2_pud_free(struct kvm *kvm, pud_t *pud) > --- a/arch/arm64/kernel/hibernate.c~arm64-add-support-for-folded-p4d-page-tables > +++ a/arch/arm64/kernel/hibernate.c > @@ -184,6 +184,7 @@ static int trans_pgd_map_page(pgd_t *tra > pgprot_t pgprot) > { > pgd_t *pgdp; > + p4d_t *p4dp; > pud_t *pudp; > pmd_t *pmdp; > pte_t *ptep; > @@ -196,7 +197,15 @@ static int trans_pgd_map_page(pgd_t *tra > pgd_populate(&init_mm, pgdp, pudp); > } > > - pudp = pud_offset(pgdp, dst_addr); > + p4dp = p4d_offset(pgdp, dst_addr); > + if (p4d_none(READ_ONCE(*p4dp))) { > + pudp = (void *)get_safe_page(GFP_ATOMIC); > + if (!pudp) > + return -ENOMEM; > + p4d_populate(&init_mm, p4dp, pudp); > + } > + > + pudp = pud_offset(p4dp, dst_addr); > if (pud_none(READ_ONCE(*pudp))) { > pmdp = (void *)get_safe_page(GFP_ATOMIC); > if (!pmdp) > @@ -419,7 +428,7 @@ static int copy_pmd(pud_t *dst_pudp, pud > return 0; > } > > -static int copy_pud(pgd_t *dst_pgdp, pgd_t *src_pgdp, unsigned long start, > +static int copy_pud(p4d_t *dst_p4dp, p4d_t *src_p4dp, unsigned long start, > unsigned long end) > { > pud_t *dst_pudp; > @@ -427,15 +436,15 @@ static int copy_pud(pgd_t *dst_pgdp, pgd > unsigned long next; > unsigned long addr = start; > > - if (pgd_none(READ_ONCE(*dst_pgdp))) { > + if (p4d_none(READ_ONCE(*dst_p4dp))) { > dst_pudp = (pud_t *)get_safe_page(GFP_ATOMIC); > if (!dst_pudp) > return -ENOMEM; > - pgd_populate(&init_mm, dst_pgdp, dst_pudp); > + p4d_populate(&init_mm, dst_p4dp, dst_pudp); > } > - dst_pudp = pud_offset(dst_pgdp, start); > + dst_pudp = pud_offset(dst_p4dp, start); > > - src_pudp = pud_offset(src_pgdp, start); > + src_pudp = pud_offset(src_p4dp, start); > do { > pud_t pud = READ_ONCE(*src_pudp); > > @@ -454,6 +463,27 @@ static int copy_pud(pgd_t *dst_pgdp, pgd > return 0; > } > > +static int copy_p4d(pgd_t *dst_pgdp, pgd_t *src_pgdp, unsigned long start, > + unsigned long end) > +{ > + p4d_t *dst_p4dp; > + p4d_t *src_p4dp; > + unsigned long next; > + unsigned long addr = start; > + > + dst_p4dp = p4d_offset(dst_pgdp, start); > + src_p4dp = p4d_offset(src_pgdp, start); > + do { > + next = p4d_addr_end(addr, end); > + if (p4d_none(READ_ONCE(*src_p4dp))) > + continue; > + if (copy_pud(dst_p4dp, src_p4dp, addr, next)) > + return -ENOMEM; > + } while (dst_p4dp++, src_p4dp++, addr = next, addr != end); > + > + return 0; > +} > + > static int copy_page_tables(pgd_t *dst_pgdp, unsigned long start, > unsigned long end) > { > @@ -466,7 +496,7 @@ static int copy_page_tables(pgd_t *dst_p > next = pgd_addr_end(addr, end); > if (pgd_none(READ_ONCE(*src_pgdp))) > continue; > - if (copy_pud(dst_pgdp, src_pgdp, addr, next)) > + if (copy_p4d(dst_pgdp, src_pgdp, addr, next)) > return -ENOMEM; > } while (dst_pgdp++, src_pgdp++, addr = next, addr != end); > > --- a/arch/arm64/kvm/mmu.c~arm64-add-support-for-folded-p4d-page-tables > +++ a/arch/arm64/kvm/mmu.c > @@ -158,13 +158,22 @@ static void *mmu_memory_cache_alloc(stru > > static void clear_stage2_pgd_entry(struct kvm *kvm, pgd_t *pgd, phys_addr_t addr) > { > - pud_t *pud_table __maybe_unused = stage2_pud_offset(kvm, pgd, 0UL); > + p4d_t *p4d_table __maybe_unused = stage2_p4d_offset(kvm, pgd, 0UL); > stage2_pgd_clear(kvm, pgd); > kvm_tlb_flush_vmid_ipa(kvm, addr); > - stage2_pud_free(kvm, pud_table); > + stage2_p4d_free(kvm, p4d_table); > put_page(virt_to_page(pgd)); > } > > +static void clear_stage2_p4d_entry(struct kvm *kvm, p4d_t *p4d, phys_addr_t addr) > +{ > + pud_t *pud_table __maybe_unused = stage2_pud_offset(kvm, p4d, 0); > + stage2_p4d_clear(kvm, p4d); > + kvm_tlb_flush_vmid_ipa(kvm, addr); > + stage2_pud_free(kvm, pud_table); > + put_page(virt_to_page(p4d)); > +} > + > static void clear_stage2_pud_entry(struct kvm *kvm, pud_t *pud, phys_addr_t addr) > { > pmd_t *pmd_table __maybe_unused = stage2_pmd_offset(kvm, pud, 0); > @@ -208,12 +217,20 @@ static inline void kvm_pud_populate(pud_ > dsb(ishst); > } > > -static inline void kvm_pgd_populate(pgd_t *pgdp, pud_t *pudp) > +static inline void kvm_p4d_populate(p4d_t *p4dp, pud_t *pudp) > { > - WRITE_ONCE(*pgdp, kvm_mk_pgd(pudp)); > + WRITE_ONCE(*p4dp, kvm_mk_p4d(pudp)); > dsb(ishst); > } > > +static inline void kvm_pgd_populate(pgd_t *pgdp, p4d_t *p4dp) > +{ > +#ifndef __PAGETABLE_P4D_FOLDED > + WRITE_ONCE(*pgdp, kvm_mk_pgd(p4dp)); > + dsb(ishst); > +#endif > +} > + > /* > * Unmapping vs dcache management: > * > @@ -293,13 +310,13 @@ static void unmap_stage2_pmds(struct kvm > clear_stage2_pud_entry(kvm, pud, start_addr); > } > > -static void unmap_stage2_puds(struct kvm *kvm, pgd_t *pgd, > +static void unmap_stage2_puds(struct kvm *kvm, p4d_t *p4d, > phys_addr_t addr, phys_addr_t end) > { > phys_addr_t next, start_addr = addr; > pud_t *pud, *start_pud; > > - start_pud = pud = stage2_pud_offset(kvm, pgd, addr); > + start_pud = pud = stage2_pud_offset(kvm, p4d, addr); > do { > next = stage2_pud_addr_end(kvm, addr, end); > if (!stage2_pud_none(kvm, *pud)) { > @@ -317,6 +334,23 @@ static void unmap_stage2_puds(struct kvm > } while (pud++, addr = next, addr != end); > > if (stage2_pud_table_empty(kvm, start_pud)) > + clear_stage2_p4d_entry(kvm, p4d, start_addr); > +} > + > +static void unmap_stage2_p4ds(struct kvm *kvm, pgd_t *pgd, > + phys_addr_t addr, phys_addr_t end) > +{ > + phys_addr_t next, start_addr = addr; > + p4d_t *p4d, *start_p4d; > + > + start_p4d = p4d = stage2_p4d_offset(kvm, pgd, addr); > + do { > + next = stage2_p4d_addr_end(kvm, addr, end); > + if (!stage2_p4d_none(kvm, *p4d)) > + unmap_stage2_puds(kvm, p4d, addr, next); > + } while (p4d++, addr = next, addr != end); > + > + if (stage2_p4d_table_empty(kvm, start_p4d)) > clear_stage2_pgd_entry(kvm, pgd, start_addr); > } > > @@ -351,7 +385,7 @@ static void unmap_stage2_range(struct kv > break; > next = stage2_pgd_addr_end(kvm, addr, end); > if (!stage2_pgd_none(kvm, *pgd)) > - unmap_stage2_puds(kvm, pgd, addr, next); > + unmap_stage2_p4ds(kvm, pgd, addr, next); > /* > * If the range is too large, release the kvm->mmu_lock > * to prevent starvation and lockup detector warnings. > @@ -391,13 +425,13 @@ static void stage2_flush_pmds(struct kvm > } while (pmd++, addr = next, addr != end); > } > > -static void stage2_flush_puds(struct kvm *kvm, pgd_t *pgd, > +static void stage2_flush_puds(struct kvm *kvm, p4d_t *p4d, > phys_addr_t addr, phys_addr_t end) > { > pud_t *pud; > phys_addr_t next; > > - pud = stage2_pud_offset(kvm, pgd, addr); > + pud = stage2_pud_offset(kvm, p4d, addr); > do { > next = stage2_pud_addr_end(kvm, addr, end); > if (!stage2_pud_none(kvm, *pud)) { > @@ -409,6 +443,20 @@ static void stage2_flush_puds(struct kvm > } while (pud++, addr = next, addr != end); > } > > +static void stage2_flush_p4ds(struct kvm *kvm, pgd_t *pgd, > + phys_addr_t addr, phys_addr_t end) > +{ > + p4d_t *p4d; > + phys_addr_t next; > + > + p4d = stage2_p4d_offset(kvm, pgd, addr); > + do { > + next = stage2_p4d_addr_end(kvm, addr, end); > + if (!stage2_p4d_none(kvm, *p4d)) > + stage2_flush_puds(kvm, p4d, addr, next); > + } while (p4d++, addr = next, addr != end); > +} > + > static void stage2_flush_memslot(struct kvm *kvm, > struct kvm_memory_slot *memslot) > { > @@ -421,7 +469,7 @@ static void stage2_flush_memslot(struct > do { > next = stage2_pgd_addr_end(kvm, addr, end); > if (!stage2_pgd_none(kvm, *pgd)) > - stage2_flush_puds(kvm, pgd, addr, next); > + stage2_flush_p4ds(kvm, pgd, addr, next); > > if (next != end) > cond_resched_lock(&kvm->mmu_lock); > @@ -454,12 +502,21 @@ static void stage2_flush_vm(struct kvm * > > static void clear_hyp_pgd_entry(pgd_t *pgd) > { > - pud_t *pud_table __maybe_unused = pud_offset(pgd, 0UL); > + p4d_t *p4d_table __maybe_unused = p4d_offset(pgd, 0UL); > pgd_clear(pgd); > - pud_free(NULL, pud_table); > + p4d_free(NULL, p4d_table); > put_page(virt_to_page(pgd)); > } > > +static void clear_hyp_p4d_entry(p4d_t *p4d) > +{ > + pud_t *pud_table __maybe_unused = pud_offset(p4d, 0); > + VM_BUG_ON(p4d_huge(*p4d)); > + p4d_clear(p4d); > + pud_free(NULL, pud_table); > + put_page(virt_to_page(p4d)); > +} > + > static void clear_hyp_pud_entry(pud_t *pud) > { > pmd_t *pmd_table __maybe_unused = pmd_offset(pud, 0); > @@ -511,12 +568,12 @@ static void unmap_hyp_pmds(pud_t *pud, p > clear_hyp_pud_entry(pud); > } > > -static void unmap_hyp_puds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end) > +static void unmap_hyp_puds(p4d_t *p4d, phys_addr_t addr, phys_addr_t end) > { > phys_addr_t next; > pud_t *pud, *start_pud; > > - start_pud = pud = pud_offset(pgd, addr); > + start_pud = pud = pud_offset(p4d, addr); > do { > next = pud_addr_end(addr, end); > /* Hyp doesn't use huge puds */ > @@ -525,6 +582,23 @@ static void unmap_hyp_puds(pgd_t *pgd, p > } while (pud++, addr = next, addr != end); > > if (hyp_pud_table_empty(start_pud)) > + clear_hyp_p4d_entry(p4d); > +} > + > +static void unmap_hyp_p4ds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end) > +{ > + phys_addr_t next; > + p4d_t *p4d, *start_p4d; > + > + start_p4d = p4d = p4d_offset(pgd, addr); > + do { > + next = p4d_addr_end(addr, end); > + /* Hyp doesn't use huge p4ds */ > + if (!p4d_none(*p4d)) > + unmap_hyp_puds(p4d, addr, next); > + } while (p4d++, addr = next, addr != end); > + > + if (hyp_p4d_table_empty(start_p4d)) > clear_hyp_pgd_entry(pgd); > } > > @@ -548,7 +622,7 @@ static void __unmap_hyp_range(pgd_t *pgd > do { > next = pgd_addr_end(addr, end); > if (!pgd_none(*pgd)) > - unmap_hyp_puds(pgd, addr, next); > + unmap_hyp_p4ds(pgd, addr, next); > } while (pgd++, addr = next, addr != end); > } > > @@ -658,7 +732,7 @@ static int create_hyp_pmd_mappings(pud_t > return 0; > } > > -static int create_hyp_pud_mappings(pgd_t *pgd, unsigned long start, > +static int create_hyp_pud_mappings(p4d_t *p4d, unsigned long start, > unsigned long end, unsigned long pfn, > pgprot_t prot) > { > @@ -669,7 +743,7 @@ static int create_hyp_pud_mappings(pgd_t > > addr = start; > do { > - pud = pud_offset(pgd, addr); > + pud = pud_offset(p4d, addr); > > if (pud_none_or_clear_bad(pud)) { > pmd = pmd_alloc_one(NULL, addr); > @@ -691,12 +765,45 @@ static int create_hyp_pud_mappings(pgd_t > return 0; > } > > +static int create_hyp_p4d_mappings(pgd_t *pgd, unsigned long start, > + unsigned long end, unsigned long pfn, > + pgprot_t prot) > +{ > + p4d_t *p4d; > + pud_t *pud; > + unsigned long addr, next; > + int ret; > + > + addr = start; > + do { > + p4d = p4d_offset(pgd, addr); > + > + if (p4d_none(*p4d)) { > + pud = pud_alloc_one(NULL, addr); > + if (!pud) { > + kvm_err("Cannot allocate Hyp pud\n"); > + return -ENOMEM; > + } > + kvm_p4d_populate(p4d, pud); > + get_page(virt_to_page(p4d)); > + } > + > + next = p4d_addr_end(addr, end); > + ret = create_hyp_pud_mappings(p4d, addr, next, pfn, prot); > + if (ret) > + return ret; > + pfn += (next - addr) >> PAGE_SHIFT; > + } while (addr = next, addr != end); > + > + return 0; > +} > + > static int __create_hyp_mappings(pgd_t *pgdp, unsigned long ptrs_per_pgd, > unsigned long start, unsigned long end, > unsigned long pfn, pgprot_t prot) > { > pgd_t *pgd; > - pud_t *pud; > + p4d_t *p4d; > unsigned long addr, next; > int err = 0; > > @@ -707,18 +814,18 @@ static int __create_hyp_mappings(pgd_t * > pgd = pgdp + kvm_pgd_index(addr, ptrs_per_pgd); > > if (pgd_none(*pgd)) { > - pud = pud_alloc_one(NULL, addr); > - if (!pud) { > - kvm_err("Cannot allocate Hyp pud\n"); > + p4d = p4d_alloc_one(NULL, addr); > + if (!p4d) { > + kvm_err("Cannot allocate Hyp p4d\n"); > err = -ENOMEM; > goto out; > } > - kvm_pgd_populate(pgd, pud); > + kvm_pgd_populate(pgd, p4d); > get_page(virt_to_page(pgd)); > } > > next = pgd_addr_end(addr, end); > - err = create_hyp_pud_mappings(pgd, addr, next, pfn, prot); > + err = create_hyp_p4d_mappings(pgd, addr, next, pfn, prot); > if (err) > goto out; > pfn += (next - addr) >> PAGE_SHIFT; > @@ -1015,22 +1122,40 @@ void kvm_free_stage2_pgd(struct kvm *kvm > free_pages_exact(pgd, stage2_pgd_size(kvm)); > } > > -static pud_t *stage2_get_pud(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, > +static p4d_t *stage2_get_p4d(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, > phys_addr_t addr) > { > pgd_t *pgd; > - pud_t *pud; > + p4d_t *p4d; > > pgd = kvm->arch.pgd + stage2_pgd_index(kvm, addr); > if (stage2_pgd_none(kvm, *pgd)) { > if (!cache) > return NULL; > - pud = mmu_memory_cache_alloc(cache); > - stage2_pgd_populate(kvm, pgd, pud); > + p4d = mmu_memory_cache_alloc(cache); > + stage2_pgd_populate(kvm, pgd, p4d); > get_page(virt_to_page(pgd)); > } > > - return stage2_pud_offset(kvm, pgd, addr); > + return stage2_p4d_offset(kvm, pgd, addr); > +} > + > +static pud_t *stage2_get_pud(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, > + phys_addr_t addr) > +{ > + p4d_t *p4d; > + pud_t *pud; > + > + p4d = stage2_get_p4d(kvm, cache, addr); > + if (stage2_p4d_none(kvm, *p4d)) { > + if (!cache) > + return NULL; > + pud = mmu_memory_cache_alloc(cache); > + stage2_p4d_populate(kvm, p4d, pud); > + get_page(virt_to_page(p4d)); > + } > + > + return stage2_pud_offset(kvm, p4d, addr); > } > > static pmd_t *stage2_get_pmd(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, > @@ -1423,18 +1548,18 @@ static void stage2_wp_pmds(struct kvm *k > } > > /** > - * stage2_wp_puds - write protect PGD range > + * stage2_wp_puds - write protect P4D range > * @pgd: pointer to pgd entry > * @addr: range start address > * @end: range end address > */ > -static void stage2_wp_puds(struct kvm *kvm, pgd_t *pgd, > +static void stage2_wp_puds(struct kvm *kvm, p4d_t *p4d, > phys_addr_t addr, phys_addr_t end) > { > pud_t *pud; > phys_addr_t next; > > - pud = stage2_pud_offset(kvm, pgd, addr); > + pud = stage2_pud_offset(kvm, p4d, addr); > do { > next = stage2_pud_addr_end(kvm, addr, end); > if (!stage2_pud_none(kvm, *pud)) { > @@ -1449,6 +1574,26 @@ static void stage2_wp_puds(struct kvm * > } > > /** > + * stage2_wp_p4ds - write protect PGD range > + * @pgd: pointer to pgd entry > + * @addr: range start address > + * @end: range end address > + */ > +static void stage2_wp_p4ds(struct kvm *kvm, pgd_t *pgd, > + phys_addr_t addr, phys_addr_t end) > +{ > + p4d_t *p4d; > + phys_addr_t next; > + > + p4d = stage2_p4d_offset(kvm, pgd, addr); > + do { > + next = stage2_p4d_addr_end(kvm, addr, end); > + if (!stage2_p4d_none(kvm, *p4d)) > + stage2_wp_puds(kvm, p4d, addr, next); > + } while (p4d++, addr = next, addr != end); > +} > + > +/** > * stage2_wp_range() - write protect stage2 memory region range > * @kvm: The KVM pointer > * @addr: Start address of range > @@ -1475,7 +1620,7 @@ static void stage2_wp_range(struct kvm * > break; > next = stage2_pgd_addr_end(kvm, addr, end); > if (stage2_pgd_present(kvm, *pgd)) > - stage2_wp_puds(kvm, pgd, addr, next); > + stage2_wp_p4ds(kvm, pgd, addr, next); > } while (pgd++, addr = next, addr != end); > } > > --- a/arch/arm64/mm/fault.c~arm64-add-support-for-folded-p4d-page-tables > +++ a/arch/arm64/mm/fault.c > @@ -145,6 +145,7 @@ static void show_pte(unsigned long addr) > pr_alert("[%016lx] pgd=%016llx", addr, pgd_val(pgd)); > > do { > + p4d_t *p4dp, p4d; > pud_t *pudp, pud; > pmd_t *pmdp, pmd; > pte_t *ptep, pte; > @@ -152,7 +153,13 @@ static void show_pte(unsigned long addr) > if (pgd_none(pgd) || pgd_bad(pgd)) > break; > > - pudp = pud_offset(pgdp, addr); > + p4dp = p4d_offset(pgdp, addr); > + p4d = READ_ONCE(*p4dp); > + pr_cont(", p4d=%016llx", p4d_val(p4d)); > + if (p4d_none(p4d) || p4d_bad(p4d)) > + break; > + > + pudp = pud_offset(p4dp, addr); > pud = READ_ONCE(*pudp); > pr_cont(", pud=%016llx", pud_val(pud)); > if (pud_none(pud) || pud_bad(pud)) > --- a/arch/arm64/mm/hugetlbpage.c~arm64-add-support-for-folded-p4d-page-tables > +++ a/arch/arm64/mm/hugetlbpage.c > @@ -67,11 +67,13 @@ static int find_num_contig(struct mm_str > pte_t *ptep, size_t *pgsize) > { > pgd_t *pgdp = pgd_offset(mm, addr); > + p4d_t *p4dp; > pud_t *pudp; > pmd_t *pmdp; > > *pgsize = PAGE_SIZE; > - pudp = pud_offset(pgdp, addr); > + p4dp = p4d_offset(pgdp, addr); > + pudp = pud_offset(p4dp, addr); > pmdp = pmd_offset(pudp, addr); > if ((pte_t *)pmdp == ptep) { > *pgsize = PMD_SIZE; > @@ -217,12 +219,14 @@ pte_t *huge_pte_alloc(struct mm_struct * > unsigned long addr, unsigned long sz) > { > pgd_t *pgdp; > + p4d_t *p4dp; > pud_t *pudp; > pmd_t *pmdp; > pte_t *ptep = NULL; > > pgdp = pgd_offset(mm, addr); > - pudp = pud_alloc(mm, pgdp, addr); > + p4dp = p4d_offset(pgdp, addr); > + pudp = pud_alloc(mm, p4dp, addr); > if (!pudp) > return NULL; > > @@ -261,6 +265,7 @@ pte_t *huge_pte_offset(struct mm_struct > unsigned long addr, unsigned long sz) > { > pgd_t *pgdp; > + p4d_t *p4dp; > pud_t *pudp, pud; > pmd_t *pmdp, pmd; > > @@ -268,7 +273,11 @@ pte_t *huge_pte_offset(struct mm_struct > if (!pgd_present(READ_ONCE(*pgdp))) > return NULL; > > - pudp = pud_offset(pgdp, addr); > + p4dp = p4d_offset(pgdp, addr); > + if (!p4d_present(READ_ONCE(*p4dp))) > + return NULL; > + > + pudp = pud_offset(p4dp, addr); > pud = READ_ONCE(*pudp); > if (sz != PUD_SIZE && pud_none(pud)) > return NULL; > --- a/arch/arm64/mm/kasan_init.c~arm64-add-support-for-folded-p4d-page-tables > +++ a/arch/arm64/mm/kasan_init.c > @@ -84,17 +84,17 @@ static pmd_t *__init kasan_pmd_offset(pu > return early ? pmd_offset_kimg(pudp, addr) : pmd_offset(pudp, addr); > } > > -static pud_t *__init kasan_pud_offset(pgd_t *pgdp, unsigned long addr, int node, > +static pud_t *__init kasan_pud_offset(p4d_t *p4dp, unsigned long addr, int node, > bool early) > { > - if (pgd_none(READ_ONCE(*pgdp))) { > + if (p4d_none(READ_ONCE(*p4dp))) { > phys_addr_t pud_phys = early ? > __pa_symbol(kasan_early_shadow_pud) > : kasan_alloc_zeroed_page(node); > - __pgd_populate(pgdp, pud_phys, PMD_TYPE_TABLE); > + __p4d_populate(p4dp, pud_phys, PMD_TYPE_TABLE); > } > > - return early ? pud_offset_kimg(pgdp, addr) : pud_offset(pgdp, addr); > + return early ? pud_offset_kimg(p4dp, addr) : pud_offset(p4dp, addr); > } > > static void __init kasan_pte_populate(pmd_t *pmdp, unsigned long addr, > @@ -126,11 +126,11 @@ static void __init kasan_pmd_populate(pu > } while (pmdp++, addr = next, addr != end && pmd_none(READ_ONCE(*pmdp))); > } > > -static void __init kasan_pud_populate(pgd_t *pgdp, unsigned long addr, > +static void __init kasan_pud_populate(p4d_t *p4dp, unsigned long addr, > unsigned long end, int node, bool early) > { > unsigned long next; > - pud_t *pudp = kasan_pud_offset(pgdp, addr, node, early); > + pud_t *pudp = kasan_pud_offset(p4dp, addr, node, early); > > do { > next = pud_addr_end(addr, end); > @@ -138,6 +138,18 @@ static void __init kasan_pud_populate(pg > } while (pudp++, addr = next, addr != end && pud_none(READ_ONCE(*pudp))); > } > > +static void __init kasan_p4d_populate(pgd_t *pgdp, unsigned long addr, > + unsigned long end, int node, bool early) > +{ > + unsigned long next; > + p4d_t *p4dp = p4d_offset(pgdp, addr); > + > + do { > + next = p4d_addr_end(addr, end); > + kasan_pud_populate(p4dp, addr, next, node, early); > + } while (p4dp++, addr = next, addr != end); > +} > + > static void __init kasan_pgd_populate(unsigned long addr, unsigned long end, > int node, bool early) > { > @@ -147,7 +159,7 @@ static void __init kasan_pgd_populate(un > pgdp = pgd_offset_k(addr); > do { > next = pgd_addr_end(addr, end); > - kasan_pud_populate(pgdp, addr, next, node, early); > + kasan_p4d_populate(pgdp, addr, next, node, early); > } while (pgdp++, addr = next, addr != end); > } > > --- a/arch/arm64/mm/mmu.c~arm64-add-support-for-folded-p4d-page-tables > +++ a/arch/arm64/mm/mmu.c > @@ -290,18 +290,19 @@ static void alloc_init_pud(pgd_t *pgdp, > { > unsigned long next; > pud_t *pudp; > - pgd_t pgd = READ_ONCE(*pgdp); > + p4d_t *p4dp = p4d_offset(pgdp, addr); > + p4d_t p4d = READ_ONCE(*p4dp); > > - if (pgd_none(pgd)) { > + if (p4d_none(p4d)) { > phys_addr_t pud_phys; > BUG_ON(!pgtable_alloc); > pud_phys = pgtable_alloc(PUD_SHIFT); > - __pgd_populate(pgdp, pud_phys, PUD_TYPE_TABLE); > - pgd = READ_ONCE(*pgdp); > + __p4d_populate(p4dp, pud_phys, PUD_TYPE_TABLE); > + p4d = READ_ONCE(*p4dp); > } > - BUG_ON(pgd_bad(pgd)); > + BUG_ON(p4d_bad(p4d)); > > - pudp = pud_set_fixmap_offset(pgdp, addr); > + pudp = pud_set_fixmap_offset(p4dp, addr); > do { > pud_t old_pud = READ_ONCE(*pudp); > > @@ -672,6 +673,7 @@ static void __init map_kernel(pgd_t *pgd > READ_ONCE(*pgd_offset_k(FIXADDR_START))); > } else if (CONFIG_PGTABLE_LEVELS > 3) { > pgd_t *bm_pgdp; > + p4d_t *bm_p4dp; > pud_t *bm_pudp; > /* > * The fixmap shares its top level pgd entry with the kernel > @@ -681,7 +683,8 @@ static void __init map_kernel(pgd_t *pgd > */ > BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES)); > bm_pgdp = pgd_offset_raw(pgdp, FIXADDR_START); > - bm_pudp = pud_set_fixmap_offset(bm_pgdp, FIXADDR_START); > + bm_p4dp = p4d_offset(bm_pgdp, FIXADDR_START); > + bm_pudp = pud_set_fixmap_offset(bm_p4dp, FIXADDR_START); > pud_populate(&init_mm, bm_pudp, lm_alias(bm_pmd)); > pud_clear_fixmap(); > } else { > @@ -715,6 +718,7 @@ void __init paging_init(void) > int kern_addr_valid(unsigned long addr) > { > pgd_t *pgdp; > + p4d_t *p4dp; > pud_t *pudp, pud; > pmd_t *pmdp, pmd; > pte_t *ptep, pte; > @@ -726,7 +730,11 @@ int kern_addr_valid(unsigned long addr) > if (pgd_none(READ_ONCE(*pgdp))) > return 0; > > - pudp = pud_offset(pgdp, addr); > + p4dp = p4d_offset(pgdp, addr); > + if (p4d_none(READ_ONCE(*p4dp))) > + return 0; > + > + pudp = pud_offset(p4dp, addr); > pud = READ_ONCE(*pudp); > if (pud_none(pud)) > return 0; > @@ -1069,6 +1077,7 @@ int __meminit vmemmap_populate(unsigned > unsigned long addr = start; > unsigned long next; > pgd_t *pgdp; > + p4d_t *p4dp; > pud_t *pudp; > pmd_t *pmdp; > > @@ -1079,7 +1088,11 @@ int __meminit vmemmap_populate(unsigned > if (!pgdp) > return -ENOMEM; > > - pudp = vmemmap_pud_populate(pgdp, addr, node); > + p4dp = vmemmap_p4d_populate(pgdp, addr, node); > + if (!p4dp) > + return -ENOMEM; > + > + pudp = vmemmap_pud_populate(p4dp, addr, node); > if (!pudp) > return -ENOMEM; > > @@ -1114,11 +1127,12 @@ void vmemmap_free(unsigned long start, u > static inline pud_t * fixmap_pud(unsigned long addr) > { > pgd_t *pgdp = pgd_offset_k(addr); > - pgd_t pgd = READ_ONCE(*pgdp); > + p4d_t *p4dp = p4d_offset(pgdp, addr); > + p4d_t p4d = READ_ONCE(*p4dp); > > - BUG_ON(pgd_none(pgd) || pgd_bad(pgd)); > + BUG_ON(p4d_none(p4d) || p4d_bad(p4d)); > > - return pud_offset_kimg(pgdp, addr); > + return pud_offset_kimg(p4dp, addr); > } > > static inline pmd_t * fixmap_pmd(unsigned long addr) > @@ -1144,25 +1158,27 @@ static inline pte_t * fixmap_pte(unsigne > */ > void __init early_fixmap_init(void) > { > - pgd_t *pgdp, pgd; > + pgd_t *pgdp; > + p4d_t *p4dp, p4d; > pud_t *pudp; > pmd_t *pmdp; > unsigned long addr = FIXADDR_START; > > pgdp = pgd_offset_k(addr); > - pgd = READ_ONCE(*pgdp); > + p4dp = p4d_offset(pgdp, addr); > + p4d = READ_ONCE(*p4dp); > if (CONFIG_PGTABLE_LEVELS > 3 && > - !(pgd_none(pgd) || pgd_page_paddr(pgd) == __pa_symbol(bm_pud))) { > + !(p4d_none(p4d) || p4d_page_paddr(p4d) == __pa_symbol(bm_pud))) { > /* > * We only end up here if the kernel mapping and the fixmap > * share the top level pgd entry, which should only happen on > * 16k/4 levels configurations. > */ > BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES)); > - pudp = pud_offset_kimg(pgdp, addr); > + pudp = pud_offset_kimg(p4dp, addr); > } else { > - if (pgd_none(pgd)) > - __pgd_populate(pgdp, __pa_symbol(bm_pud), PUD_TYPE_TABLE); > + if (p4d_none(p4d)) > + __p4d_populate(p4dp, __pa_symbol(bm_pud), PUD_TYPE_TABLE); > pudp = fixmap_pud(addr); > } > if (pud_none(READ_ONCE(*pudp))) > --- a/arch/arm64/mm/pageattr.c~arm64-add-support-for-folded-p4d-page-tables > +++ a/arch/arm64/mm/pageattr.c > @@ -198,6 +198,7 @@ void __kernel_map_pages(struct page *pag > bool kernel_page_present(struct page *page) > { > pgd_t *pgdp; > + p4d_t *p4dp; > pud_t *pudp, pud; > pmd_t *pmdp, pmd; > pte_t *ptep; > @@ -210,7 +211,11 @@ bool kernel_page_present(struct page *pa > if (pgd_none(READ_ONCE(*pgdp))) > return false; > > - pudp = pud_offset(pgdp, addr); > + p4dp = p4d_offset(pgdp, addr); > + if (p4d_none(READ_ONCE(*p4dp))) > + return false; > + > + pudp = pud_offset(p4dp, addr); > pud = READ_ONCE(*pudp); > if (pud_none(pud)) > return false; > _ > -- Sincerely yours, Mike.