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kernel-fxtec-pro1x/arch/arm64/include/asm/pgtable-hwdef.h
Catalin Marinas 2f4b829c62 arm64: Add support for hardware updates of the access and dirty pte bits 
The ARMv8.1 architecture extensions introduce support for hardware
updates of the access and dirty information in page table entries. With
TCR_EL1.HA enabled, when the CPU accesses an address with the PTE_AF bit
cleared in the page table, instead of raising an access flag fault the
CPU sets the actual page table entry bit. To ensure that kernel
modifications to the page tables do not inadvertently revert a change
introduced by hardware updates, the exclusive monitor (ldxr/stxr) is
adopted in the pte accessors.

When TCR_EL1.HD is enabled, a write access to a memory location with the
DBM (Dirty Bit Management) bit set in the corresponding pte
automatically clears the read-only bit (AP[2]). Such DBM bit maps onto
the Linux PTE_WRITE bit and to check whether a writable (DBM set) page
is dirty, the kernel tests the PTE_RDONLY bit. In order to allow
read-only and dirty pages, the kernel needs to preserve the software
dirty bit. The hardware dirty status is transferred to the software
dirty bit in ptep_set_wrprotect() (using load/store exclusive loop) and
pte_modify().

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27 11:08:39 +01:00

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/*
* Copyright (C) 2012 ARM Ltd.
*
* 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/>.
*/
#ifndef __ASM_PGTABLE_HWDEF_H
#define __ASM_PGTABLE_HWDEF_H
#define PTRS_PER_PTE (1 << (PAGE_SHIFT - 3))
/*
* PMD_SHIFT determines the size a level 2 page table entry can map.
*/
#if CONFIG_PGTABLE_LEVELS > 2
#define PMD_SHIFT ((PAGE_SHIFT - 3) * 2 + 3)
#define PMD_SIZE (_AC(1, UL) << PMD_SHIFT)
#define PMD_MASK (~(PMD_SIZE-1))
#define PTRS_PER_PMD PTRS_PER_PTE
#endif
/*
* PUD_SHIFT determines the size a level 1 page table entry can map.
*/
#if CONFIG_PGTABLE_LEVELS > 3
#define PUD_SHIFT ((PAGE_SHIFT - 3) * 3 + 3)
#define PUD_SIZE (_AC(1, UL) << PUD_SHIFT)
#define PUD_MASK (~(PUD_SIZE-1))
#define PTRS_PER_PUD PTRS_PER_PTE
#endif
/*
* PGDIR_SHIFT determines the size a top-level page table entry can map
* (depending on the configuration, this level can be 0, 1 or 2).
*/
#define PGDIR_SHIFT ((PAGE_SHIFT - 3) * CONFIG_PGTABLE_LEVELS + 3)
#define PGDIR_SIZE (_AC(1, UL) << PGDIR_SHIFT)
#define PGDIR_MASK (~(PGDIR_SIZE-1))
#define PTRS_PER_PGD (1 << (VA_BITS - PGDIR_SHIFT))
/*
* Section address mask and size definitions.
*/
#define SECTION_SHIFT PMD_SHIFT
#define SECTION_SIZE (_AC(1, UL) << SECTION_SHIFT)
#define SECTION_MASK (~(SECTION_SIZE-1))
/*
* Hardware page table definitions.
*
* Level 1 descriptor (PUD).
*/
#define PUD_TYPE_TABLE (_AT(pudval_t, 3) << 0)
#define PUD_TABLE_BIT (_AT(pgdval_t, 1) << 1)
#define PUD_TYPE_MASK (_AT(pgdval_t, 3) << 0)
#define PUD_TYPE_SECT (_AT(pgdval_t, 1) << 0)
/*
* Level 2 descriptor (PMD).
*/
#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)
/*
* Section
*/
#define PMD_SECT_VALID (_AT(pmdval_t, 1) << 0)
#define PMD_SECT_PROT_NONE (_AT(pmdval_t, 1) << 58)
#define PMD_SECT_USER (_AT(pmdval_t, 1) << 6) /* AP[1] */
#define PMD_SECT_RDONLY (_AT(pmdval_t, 1) << 7) /* AP[2] */
#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_UXN (_AT(pmdval_t, 1) << 54)
/*
* AttrIndx[2:0] encoding (mapping attributes defined in the MAIR* registers).
*/
#define PMD_ATTRINDX(t) (_AT(pmdval_t, (t)) << 2)
#define PMD_ATTRINDX_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_USER (_AT(pteval_t, 1) << 6) /* AP[1] */
#define PTE_RDONLY (_AT(pteval_t, 1) << 7) /* AP[2] */
#define PTE_SHARED (_AT(pteval_t, 3) << 8) /* SH[1:0], inner shareable */
#define PTE_AF (_AT(pteval_t, 1) << 10) /* Access Flag */
#define PTE_NG (_AT(pteval_t, 1) << 11) /* nG */
#define PTE_DBM (_AT(pteval_t, 1) << 51) /* Dirty Bit Management */
#define PTE_PXN (_AT(pteval_t, 1) << 53) /* Privileged XN */
#define PTE_UXN (_AT(pteval_t, 1) << 54) /* User XN */
/*
* AttrIndx[2:0] encoding (mapping attributes defined in the MAIR* registers).
*/
#define PTE_ATTRINDX(t) (_AT(pteval_t, (t)) << 2)
#define PTE_ATTRINDX_MASK (_AT(pteval_t, 7) << 2)
/*
* 2nd stage PTE definitions
*/
#define PTE_S2_RDONLY (_AT(pteval_t, 1) << 6) /* HAP[2:1] */
#define PTE_S2_RDWR (_AT(pteval_t, 3) << 6) /* HAP[2:1] */
#define PMD_S2_RDONLY (_AT(pmdval_t, 1) << 6) /* HAP[2:1] */
#define PMD_S2_RDWR (_AT(pmdval_t, 3) << 6) /* HAP[2:1] */
/*
* Memory Attribute override for Stage-2 (MemAttr[3:0])
*/
#define PTE_S2_MEMATTR(t) (_AT(pteval_t, (t)) << 2)
#define PTE_S2_MEMATTR_MASK (_AT(pteval_t, 0xf) << 2)
/*
* EL2/HYP PTE/PMD definitions
*/
#define PMD_HYP PMD_SECT_USER
#define PTE_HYP PTE_USER
/*
* Highest possible physical address supported.
*/
#define PHYS_MASK_SHIFT (48)
#define PHYS_MASK ((UL(1) << PHYS_MASK_SHIFT) - 1)
/*
* TCR flags.
*/
#define TCR_T0SZ_OFFSET 0
#define TCR_T1SZ_OFFSET 16
#define TCR_T0SZ(x) ((UL(64) - (x)) << TCR_T0SZ_OFFSET)
#define TCR_T1SZ(x) ((UL(64) - (x)) << TCR_T1SZ_OFFSET)
#define TCR_TxSZ(x) (TCR_T0SZ(x) | TCR_T1SZ(x))
#define TCR_TxSZ_WIDTH 6
#define TCR_IRGN_NC ((UL(0) << 8) | (UL(0) << 24))
#define TCR_IRGN_WBWA ((UL(1) << 8) | (UL(1) << 24))
#define TCR_IRGN_WT ((UL(2) << 8) | (UL(2) << 24))
#define TCR_IRGN_WBnWA ((UL(3) << 8) | (UL(3) << 24))
#define TCR_IRGN_MASK ((UL(3) << 8) | (UL(3) << 24))
#define TCR_ORGN_NC ((UL(0) << 10) | (UL(0) << 26))
#define TCR_ORGN_WBWA ((UL(1) << 10) | (UL(1) << 26))
#define TCR_ORGN_WT ((UL(2) << 10) | (UL(2) << 26))
#define TCR_ORGN_WBnWA ((UL(3) << 10) | (UL(3) << 26))
#define TCR_ORGN_MASK ((UL(3) << 10) | (UL(3) << 26))
#define TCR_SHARED ((UL(3) << 12) | (UL(3) << 28))
#define TCR_TG0_4K (UL(0) << 14)
#define TCR_TG0_64K (UL(1) << 14)
#define TCR_TG0_16K (UL(2) << 14)
#define TCR_TG1_16K (UL(1) << 30)
#define TCR_TG1_4K (UL(2) << 30)
#define TCR_TG1_64K (UL(3) << 30)
#define TCR_ASID16 (UL(1) << 36)
#define TCR_TBI0 (UL(1) << 37)
#define TCR_HA (UL(1) << 39)
#define TCR_HD (UL(1) << 40)
#endif
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