linux/arch/arm/include/asm/pgtable-3level-hwdef.h

130 lines
4.3 KiB
C
Raw Permalink Normal View History

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* arch/arm/include/asm/pgtable-3level-hwdef.h
*
* Copyright (C) 2011 ARM Ltd.
* Author: Catalin Marinas <catalin.marinas@arm.com>
*/
#ifndef _ASM_PGTABLE_3LEVEL_HWDEF_H
#define _ASM_PGTABLE_3LEVEL_HWDEF_H
/*
* Hardware page table definitions.
*
* + Level 1/2 descriptor
* - common
*/
mm/arm: use macros to define pmd/pud helpers It's already confusing that ARM 2-level v.s. 3-level defines SECT bit differently on pmd/puds. Always use a macro which is much clearer. Link: https://lkml.kernel.org/r/20240318200404.448346-7-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Cc: Bjorn Andersson <andersson@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Konrad Dybcio <konrad.dybcio@linaro.org> Cc: Fabio Estevam <festevam@denx.de> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Mark Salter <msalter@redhat.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-18 16:03:56 -04:00
#define PUD_TABLE_BIT (_AT(pmdval_t, 1) << 1)
#define PMD_TYPE_MASK (_AT(pmdval_t, 3) << 0)
#define PMD_TYPE_FAULT (_AT(pmdval_t, 0) << 0)
#define PMD_TYPE_TABLE (_AT(pmdval_t, 3) << 0)
#define PMD_TYPE_SECT (_AT(pmdval_t, 1) << 0)
#define PMD_TABLE_BIT (_AT(pmdval_t, 1) << 1)
#define PMD_BIT4 (_AT(pmdval_t, 0))
#define PMD_DOMAIN(x) (_AT(pmdval_t, 0))
#define PMD_APTABLE_SHIFT (61)
#define PMD_APTABLE (_AT(pgdval_t, 3) << PGD_APTABLE_SHIFT)
#define PMD_PXNTABLE (_AT(pgdval_t, 1) << 59)
/*
* - section
*/
#define PMD_SECT_BUFFERABLE (_AT(pmdval_t, 1) << 2)
#define PMD_SECT_CACHEABLE (_AT(pmdval_t, 1) << 3)
#define PMD_SECT_USER (_AT(pmdval_t, 1) << 6) /* AP[1] */
#define PMD_SECT_AP2 (_AT(pmdval_t, 1) << 7) /* read only */
#define PMD_SECT_S (_AT(pmdval_t, 3) << 8)
#define PMD_SECT_AF (_AT(pmdval_t, 1) << 10)
#define PMD_SECT_nG (_AT(pmdval_t, 1) << 11)
#define PMD_SECT_PXN (_AT(pmdval_t, 1) << 53)
#define PMD_SECT_XN (_AT(pmdval_t, 1) << 54)
#define PMD_SECT_AP_WRITE (_AT(pmdval_t, 0))
#define PMD_SECT_AP_READ (_AT(pmdval_t, 0))
#define PMD_SECT_AP1 (_AT(pmdval_t, 1) << 6)
#define PMD_SECT_TEX(x) (_AT(pmdval_t, 0))
/*
* AttrIndx[2:0] encoding (mapping attributes defined in the MAIR* registers).
*/
#define PMD_SECT_UNCACHED (_AT(pmdval_t, 0) << 2) /* strongly ordered */
#define PMD_SECT_BUFFERED (_AT(pmdval_t, 1) << 2) /* normal non-cacheable */
#define PMD_SECT_WT (_AT(pmdval_t, 2) << 2) /* normal inner write-through */
#define PMD_SECT_WB (_AT(pmdval_t, 3) << 2) /* normal inner write-back */
#define PMD_SECT_WBWA (_AT(pmdval_t, 7) << 2) /* normal inner write-alloc */
#define PMD_SECT_CACHE_MASK (_AT(pmdval_t, 7) << 2)
/*
* + Level 3 descriptor (PTE)
*/
#define PTE_TYPE_MASK (_AT(pteval_t, 3) << 0)
#define PTE_TYPE_FAULT (_AT(pteval_t, 0) << 0)
#define PTE_TYPE_PAGE (_AT(pteval_t, 3) << 0)
#define PTE_TABLE_BIT (_AT(pteval_t, 1) << 1)
#define PTE_BUFFERABLE (_AT(pteval_t, 1) << 2) /* AttrIndx[0] */
#define PTE_CACHEABLE (_AT(pteval_t, 1) << 3) /* AttrIndx[1] */
#define PTE_AP2 (_AT(pteval_t, 1) << 7) /* AP[2] */
#define PTE_EXT_SHARED (_AT(pteval_t, 3) << 8) /* SH[1:0], inner shareable */
#define PTE_EXT_AF (_AT(pteval_t, 1) << 10) /* Access Flag */
#define PTE_EXT_NG (_AT(pteval_t, 1) << 11) /* nG */
#define PTE_EXT_PXN (_AT(pteval_t, 1) << 53) /* PXN */
#define PTE_EXT_XN (_AT(pteval_t, 1) << 54) /* XN */
/*
* 40-bit physical address supported.
*/
#define PHYS_MASK_SHIFT (40)
#define PHYS_MASK ((1ULL << PHYS_MASK_SHIFT) - 1)
ARM: 9358/2: Implement PAN for LPAE by TTBR0 page table walks disablement With LPAE enabled, privileged no-access cannot be enforced using CPU domains as such feature is not available. This patch implements PAN by disabling TTBR0 page table walks while in kernel mode. The ARM architecture allows page table walks to be split between TTBR0 and TTBR1. With LPAE enabled, the split is defined by a combination of TTBCR T0SZ and T1SZ bits. Currently, an LPAE-enabled kernel uses TTBR0 for user addresses and TTBR1 for kernel addresses with the VMSPLIT_2G and VMSPLIT_3G configurations. The main advantage for the 3:1 split is that TTBR1 is reduced to 2 levels, so potentially faster TLB refill (though usually the first level entries are already cached in the TLB). The PAN support on LPAE-enabled kernels uses TTBR0 when running in user space or in kernel space during user access routines (TTBCR T0SZ and T1SZ are both 0). When running user accesses are disabled in kernel mode, TTBR0 page table walks are disabled by setting TTBCR.EPD0. TTBR1 is used for kernel accesses (including loadable modules; anything covered by swapper_pg_dir) by reducing the TTBCR.T0SZ to the minimum (2^(32-7) = 32MB). To avoid user accesses potentially hitting stale TLB entries, the ASID is switched to 0 (reserved) by setting TTBCR.A1 and using the ASID value in TTBR1. The difference from a non-PAN kernel is that with the 3:1 memory split, TTBR1 always uses 3 levels of page tables. As part of the change we are using preprocessor elif definied() clauses so balance these clauses by converting relevant precedingt ifdef clauses to if defined() clauses. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Florian Fainelli <florian.fainelli@broadcom.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2024-03-25 08:31:13 +01:00
#ifndef CONFIG_CPU_TTBR0_PAN
/*
* TTBR0/TTBR1 split (PAGE_OFFSET):
* 0x40000000: T0SZ = 2, T1SZ = 0 (not used)
* 0x80000000: T0SZ = 0, T1SZ = 1
* 0xc0000000: T0SZ = 0, T1SZ = 2
*
* Only use this feature if PHYS_OFFSET <= PAGE_OFFSET, otherwise
* booting secondary CPUs would end up using TTBR1 for the identity
* mapping set up in TTBR0.
*/
#if defined CONFIG_VMSPLIT_2G
#define TTBR1_OFFSET 16 /* skip two L1 entries */
#elif defined CONFIG_VMSPLIT_3G
#define TTBR1_OFFSET (4096 * (1 + 3)) /* only L2, skip pgd + 3*pmd */
#else
#define TTBR1_OFFSET 0
#endif
#define TTBR1_SIZE (((PAGE_OFFSET >> 30) - 1) << 16)
ARM: 9358/2: Implement PAN for LPAE by TTBR0 page table walks disablement With LPAE enabled, privileged no-access cannot be enforced using CPU domains as such feature is not available. This patch implements PAN by disabling TTBR0 page table walks while in kernel mode. The ARM architecture allows page table walks to be split between TTBR0 and TTBR1. With LPAE enabled, the split is defined by a combination of TTBCR T0SZ and T1SZ bits. Currently, an LPAE-enabled kernel uses TTBR0 for user addresses and TTBR1 for kernel addresses with the VMSPLIT_2G and VMSPLIT_3G configurations. The main advantage for the 3:1 split is that TTBR1 is reduced to 2 levels, so potentially faster TLB refill (though usually the first level entries are already cached in the TLB). The PAN support on LPAE-enabled kernels uses TTBR0 when running in user space or in kernel space during user access routines (TTBCR T0SZ and T1SZ are both 0). When running user accesses are disabled in kernel mode, TTBR0 page table walks are disabled by setting TTBCR.EPD0. TTBR1 is used for kernel accesses (including loadable modules; anything covered by swapper_pg_dir) by reducing the TTBCR.T0SZ to the minimum (2^(32-7) = 32MB). To avoid user accesses potentially hitting stale TLB entries, the ASID is switched to 0 (reserved) by setting TTBCR.A1 and using the ASID value in TTBR1. The difference from a non-PAN kernel is that with the 3:1 memory split, TTBR1 always uses 3 levels of page tables. As part of the change we are using preprocessor elif definied() clauses so balance these clauses by converting relevant precedingt ifdef clauses to if defined() clauses. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Florian Fainelli <florian.fainelli@broadcom.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2024-03-25 08:31:13 +01:00
#else
/*
* With CONFIG_CPU_TTBR0_PAN enabled, TTBR1 is only used during uaccess
* disabled regions when TTBR0 is disabled.
*/
#define TTBR1_OFFSET 0 /* pointing to swapper_pg_dir */
#define TTBR1_SIZE 0 /* TTBR1 size controlled via TTBCR.T0SZ */
#endif
/*
* TTBCR register bits.
*
* The ORGN0 and IRGN0 bits enables different forms of caching when
* walking the translation table. Clearing these bits (which is claimed
* to be the reset default) means "normal memory, [outer|inner]
* non-cacheable"
*/
#define TTBCR_EAE (1 << 31)
#define TTBCR_IMP (1 << 30)
#define TTBCR_SH1_MASK (3 << 28)
#define TTBCR_ORGN1_MASK (3 << 26)
#define TTBCR_IRGN1_MASK (3 << 24)
#define TTBCR_EPD1 (1 << 23)
#define TTBCR_A1 (1 << 22)
#define TTBCR_T1SZ_MASK (7 << 16)
#define TTBCR_SH0_MASK (3 << 12)
#define TTBCR_ORGN0_MASK (3 << 10)
#define TTBCR_IRGN0_MASK (3 << 8)
#define TTBCR_EPD0 (1 << 7)
#define TTBCR_T0SZ_MASK (7 << 0)
#endif