linux/arch/arm64/include/asm/pgtable-hwdef.h
Catalin Marinas 8e620b0476 arm64: Distinguish between user and kernel XN bits
On AArch64, the meaning of the XN bit has changed to UXN (user). The PXN
(privileged) bit must be set to prevent kernel execution. Without the
PXN bit set, the CPU may speculatively access device memory. This patch
ensures that all the mappings that the kernel must not execute from
(including user mappings) have the PXN bit set.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2012-11-16 15:50:25 +00:00

97 lines
3.2 KiB
C

/*
* 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
#ifdef CONFIG_ARM64_64K_PAGES
#include <asm/pgtable-2level-hwdef.h>
#else
#include <asm/pgtable-3level-hwdef.h>
#endif
/*
* Hardware page table definitions.
*
* 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)
/*
* Section
*/
#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_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_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)
/*
* 40-bit physical address supported.
*/
#define PHYS_MASK_SHIFT (40)
#define PHYS_MASK ((UL(1) << PHYS_MASK_SHIFT) - 1)
/*
* TCR flags.
*/
#define TCR_TxSZ(x) (((UL(64) - (x)) << 16) | ((UL(64) - (x)) << 0))
#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_64K (UL(1) << 14)
#define TCR_TG1_64K (UL(1) << 30)
#define TCR_IPS_40BIT (UL(2) << 32)
#define TCR_ASID16 (UL(1) << 36)
#endif