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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 503 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Enrico Weigelt <info@metux.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-03 07:44:50 +02:00
/* SPDX-License-Identifier: GPL-2.0-only */
arm64: MMU fault handling and page table management This patch adds support for the handling of the MMU faults (exception entry code introduced by a previous patch) and page table management. The user translation table is pointed to by TTBR0 and the kernel one (swapper_pg_dir) by TTBR1. There is no translation information shared or address space overlapping between user and kernel page tables. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-03-05 11:49:27 +00:00
/*
* Based on arch/arm/include/asm/pgalloc.h
*
* Copyright (C) 2000-2001 Russell King
* Copyright (C) 2012 ARM Ltd.
*/
#ifndef __ASM_PGALLOC_H
#define __ASM_PGALLOC_H
#include <asm/pgtable-hwdef.h>
#include <asm/processor.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
asm-generic: pgalloc: provide generic pgd_free() Most architectures define pgd_free() as a wrapper for free_page(). Provide a generic version in asm-generic/pgalloc.h and enable its use for most architectures. Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Pekka Enberg <penberg@kernel.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Joerg Roedel <joro@8bytes.org> Cc: Joerg Roedel <jroedel@suse.de> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Cc: Stafford Horne <shorne@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Matthew Wilcox <willy@infradead.org> Link: http://lkml.kernel.org/r/20200627143453.31835-7-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-06 23:22:47 -07:00
#define __HAVE_ARCH_PGD_FREE
asm-generic: pgalloc: provide generic pmd_alloc_one() and pmd_free_one() For most architectures that support >2 levels of page tables, pmd_alloc_one() is a wrapper for __get_free_pages(), sometimes with __GFP_ZERO and sometimes followed by memset(0) instead. More elaborate versions on arm64 and x86 account memory for the user page tables and call to pgtable_pmd_page_ctor() as the part of PMD page initialization. Move the arm64 version to include/asm-generic/pgalloc.h and use the generic version on several architectures. The pgtable_pmd_page_ctor() is a NOP when ARCH_ENABLE_SPLIT_PMD_PTLOCK is not enabled, so there is no functional change for most architectures except of the addition of __GFP_ACCOUNT for allocation of user page tables. The pmd_free() is a wrapper for free_page() in all the cases, so no functional change here. Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Pekka Enberg <penberg@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Joerg Roedel <joro@8bytes.org> Cc: Joerg Roedel <jroedel@suse.de> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Cc: Stafford Horne <shorne@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Link: http://lkml.kernel.org/r/20200627143453.31835-5-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-06 23:22:39 -07:00
#include <asm-generic/pgalloc.h>
arm64: switch to generic version of pte allocation The PTE allocations in arm64 are identical to the generic ones modulo the GFP flags. Using the generic pte_alloc_one() functions ensures that the user page tables are allocated with __GFP_ACCOUNT set. The arm64 definition of PGALLOC_GFP is removed and replaced with GFP_PGTABLE_USER for p[gum]d_alloc_one() for the user page tables and GFP_PGTABLE_KERNEL for the kernel page tables. The KVM memory cache is now using GFP_PGTABLE_USER. The mappings created with create_pgd_mapping() are now using GFP_PGTABLE_KERNEL. The conversion to the generic version of pte_free_kernel() removes the NULL check for pte. The pte_free() version on arm64 is identical to the generic one and can be simply dropped. [cai@lca.pw: fix a bogus GFP flag in pgd_alloc()] Link: https://lore.kernel.org/r/1559656836-24940-1-git-send-email-cai@lca.pw/ [and fix it more] Link: https://lore.kernel.org/linux-mm/20190617151252.GF16810@rapoport-lnx/ Link: http://lkml.kernel.org/r/1557296232-15361-5-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Guo Ren <ren_guo@c-sky.com> Cc: Helge Deller <deller@gmx.de> Cc: Ley Foon Tan <lftan@altera.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Sam Creasey <sammy@sammy.net> Cc: Vincent Chen <deanbo422@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-11 20:58:02 -07:00
arm64: move PGD_SIZE definition to pgalloc.h This will be used by KASAN latter. Signed-off-by: Andrey Ryabinin <ryabinin.a.a@gmail.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-12 18:52:57 +03:00
#define PGD_SIZE (PTRS_PER_PGD * sizeof(pgd_t))
arm64: pgalloc: consistently use PGALLOC_GFP We currently allocate different levels of page tables with a variety of differing flags, and the PGALLOC_GFP flags, intended for use when allocating any level of page table, are only used for ptes in pte_alloc_one. On x86, PGALLOC_GFP is used for all page table allocations. Currently the major differences are: * __GFP_NOTRACK -- Needed to ensure page tables are always accessible in the presence of kmemcheck to prevent recursive faults. Currently kmemcheck cannot be selected for arm64. * __GFP_REPEAT -- Causes the allocator to try to reclaim pages and retry upon a failure to allocate. * __GFP_ZERO -- Sometimes passed explicitly, sometimes zalloc variants are used. While we've no encountered issues so far, it would be preferable to be consistent. This patch ensures all levels of table are allocated in the same manner, with PGALLOC_GFP. Cc: Steve Capper <steve.capper@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-11-19 17:44:12 +00:00
arm64: expose number of page table levels on Kconfig level We would want to use number of page table level to define mm_struct. Let's expose it as CONFIG_PGTABLE_LEVELS. ARM64_PGTABLE_LEVELS is renamed to PGTABLE_LEVELS and defined before sourcing init/Kconfig: arch/Kconfig will define default value and it's sourced from init/Kconfig. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 15:45:39 -07:00
#if CONFIG_PGTABLE_LEVELS > 2
arm64: MMU fault handling and page table management This patch adds support for the handling of the MMU faults (exception entry code introduced by a previous patch) and page table management. The user translation table is pointed to by TTBR0 and the kernel one (swapper_pg_dir) by TTBR1. There is no translation information shared or address space overlapping between user and kernel page tables. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-03-05 11:49:27 +00:00
arm64: mm: Use READ_ONCE/WRITE_ONCE when accessing page tables In many cases, page tables can be accessed concurrently by either another CPU (due to things like fast gup) or by the hardware page table walker itself, which may set access/dirty bits. In such cases, it is important to use READ_ONCE/WRITE_ONCE when accessing page table entries so that entries cannot be torn, merged or subject to apparent loss of coherence due to compiler transformations. Whilst there are some scenarios where this cannot happen (e.g. pinned kernel mappings for the linear region), the overhead of using READ_ONCE /WRITE_ONCE everywhere is minimal and makes the code an awful lot easier to reason about. This patch consistently uses these macros in the arch code, as well as explicitly namespacing pointers to page table entries from the entries themselves by using adopting a 'p' suffix for the former (as is sometimes used elsewhere in the kernel source). Tested-by: Yury Norov <ynorov@caviumnetworks.com> Tested-by: Richard Ruigrok <rruigrok@codeaurora.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-15 11:14:56 +00:00
static inline void __pud_populate(pud_t *pudp, phys_addr_t pmdp, pudval_t prot)
arm64: MMU fault handling and page table management This patch adds support for the handling of the MMU faults (exception entry code introduced by a previous patch) and page table management. The user translation table is pointed to by TTBR0 and the kernel one (swapper_pg_dir) by TTBR1. There is no translation information shared or address space overlapping between user and kernel page tables. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-03-05 11:49:27 +00:00
{
arm64: mm: Use READ_ONCE/WRITE_ONCE when accessing page tables In many cases, page tables can be accessed concurrently by either another CPU (due to things like fast gup) or by the hardware page table walker itself, which may set access/dirty bits. In such cases, it is important to use READ_ONCE/WRITE_ONCE when accessing page table entries so that entries cannot be torn, merged or subject to apparent loss of coherence due to compiler transformations. Whilst there are some scenarios where this cannot happen (e.g. pinned kernel mappings for the linear region), the overhead of using READ_ONCE /WRITE_ONCE everywhere is minimal and makes the code an awful lot easier to reason about. This patch consistently uses these macros in the arch code, as well as explicitly namespacing pointers to page table entries from the entries themselves by using adopting a 'p' suffix for the former (as is sometimes used elsewhere in the kernel source). Tested-by: Yury Norov <ynorov@caviumnetworks.com> Tested-by: Richard Ruigrok <rruigrok@codeaurora.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-15 11:14:56 +00:00
set_pud(pudp, __pud(__phys_to_pud_val(pmdp) | prot));
arm64: MMU fault handling and page table management This patch adds support for the handling of the MMU faults (exception entry code introduced by a previous patch) and page table management. The user translation table is pointed to by TTBR0 and the kernel one (swapper_pg_dir) by TTBR1. There is no translation information shared or address space overlapping between user and kernel page tables. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-03-05 11:49:27 +00:00
}
arm64: mm: Use READ_ONCE/WRITE_ONCE when accessing page tables In many cases, page tables can be accessed concurrently by either another CPU (due to things like fast gup) or by the hardware page table walker itself, which may set access/dirty bits. In such cases, it is important to use READ_ONCE/WRITE_ONCE when accessing page table entries so that entries cannot be torn, merged or subject to apparent loss of coherence due to compiler transformations. Whilst there are some scenarios where this cannot happen (e.g. pinned kernel mappings for the linear region), the overhead of using READ_ONCE /WRITE_ONCE everywhere is minimal and makes the code an awful lot easier to reason about. This patch consistently uses these macros in the arch code, as well as explicitly namespacing pointers to page table entries from the entries themselves by using adopting a 'p' suffix for the former (as is sometimes used elsewhere in the kernel source). Tested-by: Yury Norov <ynorov@caviumnetworks.com> Tested-by: Richard Ruigrok <rruigrok@codeaurora.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-15 11:14:56 +00:00
static inline void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmdp)
arm64: mm: add __{pud,pgd}_populate We currently have __pmd_populate for creating a pmd table entry given the physical address of a pte, but don't have equivalents for the pud or pgd levels of table. To enable us to manipulate tables which are mapped outside of the linear mapping (where we have a PA, but not a linear map VA), it is useful to have these functions. This patch adds __{pud,pgd}_populate. As these should not be called when the kernel uses folded {pmd,pud}s, in these cases they expand to BUILD_BUG(). So long as the appropriate checks are made on the {pud,pgd} entry prior to attempting population, these should be optimized out at compile time. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-01-25 11:45:06 +00:00
{
arm64: mm: use XN table mapping attributes for user/kernel mappings As the kernel and user space page tables are strictly mutually exclusive when it comes to executable permissions, we can set the UXN table attribute on all table entries that are created while creating kernel mappings in the swapper page tables, and the PXN table attribute on all table entries that are created while creating user space mappings in user space page tables. While at it, get rid of a redundant comment. Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20210310104942.174584-4-ardb@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-03-10 11:49:42 +01:00
pudval_t pudval = PUD_TYPE_TABLE;
pudval |= (mm == &init_mm) ? PUD_TABLE_UXN : PUD_TABLE_PXN;
__pud_populate(pudp, __pa(pmdp), pudval);
arm64: mm: add __{pud,pgd}_populate We currently have __pmd_populate for creating a pmd table entry given the physical address of a pte, but don't have equivalents for the pud or pgd levels of table. To enable us to manipulate tables which are mapped outside of the linear mapping (where we have a PA, but not a linear map VA), it is useful to have these functions. This patch adds __{pud,pgd}_populate. As these should not be called when the kernel uses folded {pmd,pud}s, in these cases they expand to BUILD_BUG(). So long as the appropriate checks are made on the {pud,pgd} entry prior to attempting population, these should be optimized out at compile time. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-01-25 11:45:06 +00:00
}
#else
arm64: mm: Use READ_ONCE/WRITE_ONCE when accessing page tables In many cases, page tables can be accessed concurrently by either another CPU (due to things like fast gup) or by the hardware page table walker itself, which may set access/dirty bits. In such cases, it is important to use READ_ONCE/WRITE_ONCE when accessing page table entries so that entries cannot be torn, merged or subject to apparent loss of coherence due to compiler transformations. Whilst there are some scenarios where this cannot happen (e.g. pinned kernel mappings for the linear region), the overhead of using READ_ONCE /WRITE_ONCE everywhere is minimal and makes the code an awful lot easier to reason about. This patch consistently uses these macros in the arch code, as well as explicitly namespacing pointers to page table entries from the entries themselves by using adopting a 'p' suffix for the former (as is sometimes used elsewhere in the kernel source). Tested-by: Yury Norov <ynorov@caviumnetworks.com> Tested-by: Richard Ruigrok <rruigrok@codeaurora.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-15 11:14:56 +00:00
static inline void __pud_populate(pud_t *pudp, phys_addr_t pmdp, pudval_t prot)
arm64: mm: add __{pud,pgd}_populate We currently have __pmd_populate for creating a pmd table entry given the physical address of a pte, but don't have equivalents for the pud or pgd levels of table. To enable us to manipulate tables which are mapped outside of the linear mapping (where we have a PA, but not a linear map VA), it is useful to have these functions. This patch adds __{pud,pgd}_populate. As these should not be called when the kernel uses folded {pmd,pud}s, in these cases they expand to BUILD_BUG(). So long as the appropriate checks are made on the {pud,pgd} entry prior to attempting population, these should be optimized out at compile time. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-01-25 11:45:06 +00:00
{
BUILD_BUG();
}
arm64: expose number of page table levels on Kconfig level We would want to use number of page table level to define mm_struct. Let's expose it as CONFIG_PGTABLE_LEVELS. ARM64_PGTABLE_LEVELS is renamed to PGTABLE_LEVELS and defined before sourcing init/Kconfig: arch/Kconfig will define default value and it's sourced from init/Kconfig. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 15:45:39 -07:00
#endif /* CONFIG_PGTABLE_LEVELS > 2 */
arm64: MMU fault handling and page table management This patch adds support for the handling of the MMU faults (exception entry code introduced by a previous patch) and page table management. The user translation table is pointed to by TTBR0 and the kernel one (swapper_pg_dir) by TTBR1. There is no translation information shared or address space overlapping between user and kernel page tables. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-03-05 11:49:27 +00:00
arm64: expose number of page table levels on Kconfig level We would want to use number of page table level to define mm_struct. Let's expose it as CONFIG_PGTABLE_LEVELS. ARM64_PGTABLE_LEVELS is renamed to PGTABLE_LEVELS and defined before sourcing init/Kconfig: arch/Kconfig will define default value and it's sourced from init/Kconfig. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 15:45:39 -07:00
#if CONFIG_PGTABLE_LEVELS > 3
arm64: mm: Implement 4 levels of translation tables This patch implements 4 levels of translation tables since 3 levels of page tables with 4KB pages cannot support 40-bit physical address space described in [1] due to the following issue. It is a restriction that kernel logical memory map with 4KB + 3 levels (0xffffffc000000000-0xffffffffffffffff) cannot cover RAM region from 544GB to 1024GB in [1]. Specifically, ARM64 kernel fails to create mapping for this region in map_mem function since __phys_to_virt for this region reaches to address overflow. If SoC design follows the document, [1], over 32GB RAM would be placed from 544GB. Even 64GB system is supposed to use the region from 544GB to 576GB for only 32GB RAM. Naturally, it would reach to enable 4 levels of page tables to avoid hacking __virt_to_phys and __phys_to_virt. However, it is recommended 4 levels of page table should be only enabled if memory map is too sparse or there is about 512GB RAM. References ---------- [1]: Principles of ARM Memory Maps, White Paper, Issue C Signed-off-by: Jungseok Lee <jays.lee@samsung.com> Reviewed-by: Sungjinn Chung <sungjinn.chung@samsung.com> Acked-by: Kukjin Kim <kgene.kim@samsung.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Steve Capper <steve.capper@linaro.org> [catalin.marinas@arm.com: MEMBLOCK_INITIAL_LIMIT removed, same as PUD_SIZE] [catalin.marinas@arm.com: early_ioremap_init() updated for 4 levels] [catalin.marinas@arm.com: 48-bit VA depends on BROKEN until KVM is fixed] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Jungseok Lee <jungseoklee85@gmail.com>
2014-05-12 18:40:51 +09:00
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. [arnd@arndb.de: fix gcc-10 shift warning] Link: http://lkml.kernel.org/r/20200429185657.4085975-1-arnd@arndb.de Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: James Morse <james.morse@arm.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Julien Thierry <julien.thierry.kdev@gmail.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200414153455.21744-4-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04 16:46:23 -07:00
static inline void __p4d_populate(p4d_t *p4dp, phys_addr_t pudp, p4dval_t prot)
arm64: mm: Implement 4 levels of translation tables This patch implements 4 levels of translation tables since 3 levels of page tables with 4KB pages cannot support 40-bit physical address space described in [1] due to the following issue. It is a restriction that kernel logical memory map with 4KB + 3 levels (0xffffffc000000000-0xffffffffffffffff) cannot cover RAM region from 544GB to 1024GB in [1]. Specifically, ARM64 kernel fails to create mapping for this region in map_mem function since __phys_to_virt for this region reaches to address overflow. If SoC design follows the document, [1], over 32GB RAM would be placed from 544GB. Even 64GB system is supposed to use the region from 544GB to 576GB for only 32GB RAM. Naturally, it would reach to enable 4 levels of page tables to avoid hacking __virt_to_phys and __phys_to_virt. However, it is recommended 4 levels of page table should be only enabled if memory map is too sparse or there is about 512GB RAM. References ---------- [1]: Principles of ARM Memory Maps, White Paper, Issue C Signed-off-by: Jungseok Lee <jays.lee@samsung.com> Reviewed-by: Sungjinn Chung <sungjinn.chung@samsung.com> Acked-by: Kukjin Kim <kgene.kim@samsung.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Steve Capper <steve.capper@linaro.org> [catalin.marinas@arm.com: MEMBLOCK_INITIAL_LIMIT removed, same as PUD_SIZE] [catalin.marinas@arm.com: early_ioremap_init() updated for 4 levels] [catalin.marinas@arm.com: 48-bit VA depends on BROKEN until KVM is fixed] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Jungseok Lee <jungseoklee85@gmail.com>
2014-05-12 18:40:51 +09:00
{
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. [arnd@arndb.de: fix gcc-10 shift warning] Link: http://lkml.kernel.org/r/20200429185657.4085975-1-arnd@arndb.de Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: James Morse <james.morse@arm.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Julien Thierry <julien.thierry.kdev@gmail.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200414153455.21744-4-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04 16:46:23 -07:00
set_p4d(p4dp, __p4d(__phys_to_p4d_val(pudp) | prot));
arm64: mm: Implement 4 levels of translation tables This patch implements 4 levels of translation tables since 3 levels of page tables with 4KB pages cannot support 40-bit physical address space described in [1] due to the following issue. It is a restriction that kernel logical memory map with 4KB + 3 levels (0xffffffc000000000-0xffffffffffffffff) cannot cover RAM region from 544GB to 1024GB in [1]. Specifically, ARM64 kernel fails to create mapping for this region in map_mem function since __phys_to_virt for this region reaches to address overflow. If SoC design follows the document, [1], over 32GB RAM would be placed from 544GB. Even 64GB system is supposed to use the region from 544GB to 576GB for only 32GB RAM. Naturally, it would reach to enable 4 levels of page tables to avoid hacking __virt_to_phys and __phys_to_virt. However, it is recommended 4 levels of page table should be only enabled if memory map is too sparse or there is about 512GB RAM. References ---------- [1]: Principles of ARM Memory Maps, White Paper, Issue C Signed-off-by: Jungseok Lee <jays.lee@samsung.com> Reviewed-by: Sungjinn Chung <sungjinn.chung@samsung.com> Acked-by: Kukjin Kim <kgene.kim@samsung.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Steve Capper <steve.capper@linaro.org> [catalin.marinas@arm.com: MEMBLOCK_INITIAL_LIMIT removed, same as PUD_SIZE] [catalin.marinas@arm.com: early_ioremap_init() updated for 4 levels] [catalin.marinas@arm.com: 48-bit VA depends on BROKEN until KVM is fixed] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Jungseok Lee <jungseoklee85@gmail.com>
2014-05-12 18:40:51 +09:00
}
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. [arnd@arndb.de: fix gcc-10 shift warning] Link: http://lkml.kernel.org/r/20200429185657.4085975-1-arnd@arndb.de Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: James Morse <james.morse@arm.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Julien Thierry <julien.thierry.kdev@gmail.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200414153455.21744-4-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04 16:46:23 -07:00
static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4dp, pud_t *pudp)
arm64: mm: add __{pud,pgd}_populate We currently have __pmd_populate for creating a pmd table entry given the physical address of a pte, but don't have equivalents for the pud or pgd levels of table. To enable us to manipulate tables which are mapped outside of the linear mapping (where we have a PA, but not a linear map VA), it is useful to have these functions. This patch adds __{pud,pgd}_populate. As these should not be called when the kernel uses folded {pmd,pud}s, in these cases they expand to BUILD_BUG(). So long as the appropriate checks are made on the {pud,pgd} entry prior to attempting population, these should be optimized out at compile time. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-01-25 11:45:06 +00:00
{
arm64: mm: use XN table mapping attributes for user/kernel mappings As the kernel and user space page tables are strictly mutually exclusive when it comes to executable permissions, we can set the UXN table attribute on all table entries that are created while creating kernel mappings in the swapper page tables, and the PXN table attribute on all table entries that are created while creating user space mappings in user space page tables. While at it, get rid of a redundant comment. Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20210310104942.174584-4-ardb@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-03-10 11:49:42 +01:00
p4dval_t p4dval = P4D_TYPE_TABLE;
p4dval |= (mm == &init_mm) ? P4D_TABLE_UXN : P4D_TABLE_PXN;
__p4d_populate(p4dp, __pa(pudp), p4dval);
arm64: mm: add __{pud,pgd}_populate We currently have __pmd_populate for creating a pmd table entry given the physical address of a pte, but don't have equivalents for the pud or pgd levels of table. To enable us to manipulate tables which are mapped outside of the linear mapping (where we have a PA, but not a linear map VA), it is useful to have these functions. This patch adds __{pud,pgd}_populate. As these should not be called when the kernel uses folded {pmd,pud}s, in these cases they expand to BUILD_BUG(). So long as the appropriate checks are made on the {pud,pgd} entry prior to attempting population, these should be optimized out at compile time. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-01-25 11:45:06 +00:00
}
#else
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. [arnd@arndb.de: fix gcc-10 shift warning] Link: http://lkml.kernel.org/r/20200429185657.4085975-1-arnd@arndb.de Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: James Morse <james.morse@arm.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Julien Thierry <julien.thierry.kdev@gmail.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200414153455.21744-4-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04 16:46:23 -07:00
static inline void __p4d_populate(p4d_t *p4dp, phys_addr_t pudp, p4dval_t prot)
arm64: mm: add __{pud,pgd}_populate We currently have __pmd_populate for creating a pmd table entry given the physical address of a pte, but don't have equivalents for the pud or pgd levels of table. To enable us to manipulate tables which are mapped outside of the linear mapping (where we have a PA, but not a linear map VA), it is useful to have these functions. This patch adds __{pud,pgd}_populate. As these should not be called when the kernel uses folded {pmd,pud}s, in these cases they expand to BUILD_BUG(). So long as the appropriate checks are made on the {pud,pgd} entry prior to attempting population, these should be optimized out at compile time. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-01-25 11:45:06 +00:00
{
BUILD_BUG();
}
arm64: expose number of page table levels on Kconfig level We would want to use number of page table level to define mm_struct. Let's expose it as CONFIG_PGTABLE_LEVELS. ARM64_PGTABLE_LEVELS is renamed to PGTABLE_LEVELS and defined before sourcing init/Kconfig: arch/Kconfig will define default value and it's sourced from init/Kconfig. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14 15:45:39 -07:00
#endif /* CONFIG_PGTABLE_LEVELS > 3 */
arm64: mm: Implement 4 levels of translation tables This patch implements 4 levels of translation tables since 3 levels of page tables with 4KB pages cannot support 40-bit physical address space described in [1] due to the following issue. It is a restriction that kernel logical memory map with 4KB + 3 levels (0xffffffc000000000-0xffffffffffffffff) cannot cover RAM region from 544GB to 1024GB in [1]. Specifically, ARM64 kernel fails to create mapping for this region in map_mem function since __phys_to_virt for this region reaches to address overflow. If SoC design follows the document, [1], over 32GB RAM would be placed from 544GB. Even 64GB system is supposed to use the region from 544GB to 576GB for only 32GB RAM. Naturally, it would reach to enable 4 levels of page tables to avoid hacking __virt_to_phys and __phys_to_virt. However, it is recommended 4 levels of page table should be only enabled if memory map is too sparse or there is about 512GB RAM. References ---------- [1]: Principles of ARM Memory Maps, White Paper, Issue C Signed-off-by: Jungseok Lee <jays.lee@samsung.com> Reviewed-by: Sungjinn Chung <sungjinn.chung@samsung.com> Acked-by: Kukjin Kim <kgene.kim@samsung.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Steve Capper <steve.capper@linaro.org> [catalin.marinas@arm.com: MEMBLOCK_INITIAL_LIMIT removed, same as PUD_SIZE] [catalin.marinas@arm.com: early_ioremap_init() updated for 4 levels] [catalin.marinas@arm.com: 48-bit VA depends on BROKEN until KVM is fixed] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Jungseok Lee <jungseoklee85@gmail.com>
2014-05-12 18:40:51 +09:00
arm64: MMU fault handling and page table management This patch adds support for the handling of the MMU faults (exception entry code introduced by a previous patch) and page table management. The user translation table is pointed to by TTBR0 and the kernel one (swapper_pg_dir) by TTBR1. There is no translation information shared or address space overlapping between user and kernel page tables. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-03-05 11:49:27 +00:00
extern pgd_t *pgd_alloc(struct mm_struct *mm);
arm64: mm: Use READ_ONCE/WRITE_ONCE when accessing page tables In many cases, page tables can be accessed concurrently by either another CPU (due to things like fast gup) or by the hardware page table walker itself, which may set access/dirty bits. In such cases, it is important to use READ_ONCE/WRITE_ONCE when accessing page table entries so that entries cannot be torn, merged or subject to apparent loss of coherence due to compiler transformations. Whilst there are some scenarios where this cannot happen (e.g. pinned kernel mappings for the linear region), the overhead of using READ_ONCE /WRITE_ONCE everywhere is minimal and makes the code an awful lot easier to reason about. This patch consistently uses these macros in the arch code, as well as explicitly namespacing pointers to page table entries from the entries themselves by using adopting a 'p' suffix for the former (as is sometimes used elsewhere in the kernel source). Tested-by: Yury Norov <ynorov@caviumnetworks.com> Tested-by: Richard Ruigrok <rruigrok@codeaurora.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-15 11:14:56 +00:00
extern void pgd_free(struct mm_struct *mm, pgd_t *pgdp);
arm64: MMU fault handling and page table management This patch adds support for the handling of the MMU faults (exception entry code introduced by a previous patch) and page table management. The user translation table is pointed to by TTBR0 and the kernel one (swapper_pg_dir) by TTBR1. There is no translation information shared or address space overlapping between user and kernel page tables. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-03-05 11:49:27 +00:00
arm64: mm: Use READ_ONCE/WRITE_ONCE when accessing page tables In many cases, page tables can be accessed concurrently by either another CPU (due to things like fast gup) or by the hardware page table walker itself, which may set access/dirty bits. In such cases, it is important to use READ_ONCE/WRITE_ONCE when accessing page table entries so that entries cannot be torn, merged or subject to apparent loss of coherence due to compiler transformations. Whilst there are some scenarios where this cannot happen (e.g. pinned kernel mappings for the linear region), the overhead of using READ_ONCE /WRITE_ONCE everywhere is minimal and makes the code an awful lot easier to reason about. This patch consistently uses these macros in the arch code, as well as explicitly namespacing pointers to page table entries from the entries themselves by using adopting a 'p' suffix for the former (as is sometimes used elsewhere in the kernel source). Tested-by: Yury Norov <ynorov@caviumnetworks.com> Tested-by: Richard Ruigrok <rruigrok@codeaurora.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-15 11:14:56 +00:00
static inline void __pmd_populate(pmd_t *pmdp, phys_addr_t ptep,
arm64: MMU fault handling and page table management This patch adds support for the handling of the MMU faults (exception entry code introduced by a previous patch) and page table management. The user translation table is pointed to by TTBR0 and the kernel one (swapper_pg_dir) by TTBR1. There is no translation information shared or address space overlapping between user and kernel page tables. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-03-05 11:49:27 +00:00
pmdval_t prot)
{
arm64: mm: Use READ_ONCE/WRITE_ONCE when accessing page tables In many cases, page tables can be accessed concurrently by either another CPU (due to things like fast gup) or by the hardware page table walker itself, which may set access/dirty bits. In such cases, it is important to use READ_ONCE/WRITE_ONCE when accessing page table entries so that entries cannot be torn, merged or subject to apparent loss of coherence due to compiler transformations. Whilst there are some scenarios where this cannot happen (e.g. pinned kernel mappings for the linear region), the overhead of using READ_ONCE /WRITE_ONCE everywhere is minimal and makes the code an awful lot easier to reason about. This patch consistently uses these macros in the arch code, as well as explicitly namespacing pointers to page table entries from the entries themselves by using adopting a 'p' suffix for the former (as is sometimes used elsewhere in the kernel source). Tested-by: Yury Norov <ynorov@caviumnetworks.com> Tested-by: Richard Ruigrok <rruigrok@codeaurora.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-15 11:14:56 +00:00
set_pmd(pmdp, __pmd(__phys_to_pmd_val(ptep) | prot));
arm64: MMU fault handling and page table management This patch adds support for the handling of the MMU faults (exception entry code introduced by a previous patch) and page table management. The user translation table is pointed to by TTBR0 and the kernel one (swapper_pg_dir) by TTBR1. There is no translation information shared or address space overlapping between user and kernel page tables. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-03-05 11:49:27 +00:00
}
/*
* Populate the pmdp entry with a pointer to the pte. This pmd is part
* of the mm address space.
*/
static inline void
pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep)
{
arm64: mm: Fix VM_BUG_ON(mm != &init_mm) for trans_pgd trans_pgd_create_copy() can hit "VM_BUG_ON(mm != &init_mm)" in the function pmd_populate_kernel(). This is the combined consequence of commit 5de59884ac0e ("arm64: trans_pgd: pass NULL instead of init_mm to *_populate functions"), which replaced &init_mm with NULL and commit 59511cfd08f3 ("arm64: mm: use XN table mapping attributes for user/kernel mappings"), which introduced the VM_BUG_ON. Since the former sounds reasonable, it is better to work on the later. From the perspective of trans_pgd, two groups of functions are considered in the later one: pmd_populate_kernel() mm == NULL should be fixed, else it hits VM_BUG_ON() p?d_populate() mm == NULL means PXN, that is OK, since trans_pgd only copies a linear map, no execution will happen on the map. So it is good enough to just relax VM_BUG_ON() to disregard mm == NULL Fixes: 59511cfd08f3 ("arm64: mm: use XN table mapping attributes for user/kernel mappings") Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Cc: <stable@vger.kernel.org> # 5.13.x Cc: Ard Biesheuvel <ardb@kernel.org> Cc: James Morse <james.morse@arm.com> Cc: Matthias Brugger <mbrugger@suse.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Link: https://lore.kernel.org/r/20211112052214.9086-1-kernelfans@gmail.com Signed-off-by: Will Deacon <will@kernel.org>
2021-11-12 13:22:14 +08:00
VM_BUG_ON(mm && mm != &init_mm);
arm64: mm: use XN table mapping attributes for user/kernel mappings As the kernel and user space page tables are strictly mutually exclusive when it comes to executable permissions, we can set the UXN table attribute on all table entries that are created while creating kernel mappings in the swapper page tables, and the PXN table attribute on all table entries that are created while creating user space mappings in user space page tables. While at it, get rid of a redundant comment. Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20210310104942.174584-4-ardb@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-03-10 11:49:42 +01:00
__pmd_populate(pmdp, __pa(ptep), PMD_TYPE_TABLE | PMD_TABLE_UXN);
arm64: MMU fault handling and page table management This patch adds support for the handling of the MMU faults (exception entry code introduced by a previous patch) and page table management. The user translation table is pointed to by TTBR0 and the kernel one (swapper_pg_dir) by TTBR1. There is no translation information shared or address space overlapping between user and kernel page tables. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-03-05 11:49:27 +00:00
}
static inline void
pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep)
{
arm64: mm: use XN table mapping attributes for user/kernel mappings As the kernel and user space page tables are strictly mutually exclusive when it comes to executable permissions, we can set the UXN table attribute on all table entries that are created while creating kernel mappings in the swapper page tables, and the PXN table attribute on all table entries that are created while creating user space mappings in user space page tables. While at it, get rid of a redundant comment. Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20210310104942.174584-4-ardb@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-03-10 11:49:42 +01:00
VM_BUG_ON(mm == &init_mm);
__pmd_populate(pmdp, page_to_phys(ptep), PMD_TYPE_TABLE | PMD_TABLE_PXN);
arm64: MMU fault handling and page table management This patch adds support for the handling of the MMU faults (exception entry code introduced by a previous patch) and page table management. The user translation table is pointed to by TTBR0 and the kernel one (swapper_pg_dir) by TTBR1. There is no translation information shared or address space overlapping between user and kernel page tables. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-03-05 11:49:27 +00:00
}
#endif
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