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linux/arch/riscv/include/asm/pgtable-bits.h

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 286 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 as published by the free software foundation version 2 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 97 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141901.025053186@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-29 07:18:00 -07:00
/* SPDX-License-Identifier: GPL-2.0-only */
RISC-V: Paging and MMU This patch contains code to manage the RISC-V MMU, including definitions of the page tables and the page walking code. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:06:09 -07:00
/*
* Copyright (C) 2012 Regents of the University of California
*/
#ifndef _ASM_RISCV_PGTABLE_BITS_H
#define _ASM_RISCV_PGTABLE_BITS_H
#define _PAGE_ACCESSED_OFFSET 6
#define _PAGE_PRESENT (1 << 0)
#define _PAGE_READ (1 << 1) /* Readable */
#define _PAGE_WRITE (1 << 2) /* Writable */
#define _PAGE_EXEC (1 << 3) /* Executable */
#define _PAGE_USER (1 << 4) /* User */
#define _PAGE_GLOBAL (1 << 5) /* Global */
#define _PAGE_ACCESSED (1 << 6) /* Set by hardware on any access */
#define _PAGE_DIRTY (1 << 7) /* Set by hardware on any write */
riscv: Improve PTDUMP to show RSW with non-zero value RSW field can be used to encode 2 bits of software defined information. Currently, PTDUMP only prints "RSW" when its value is 1 or 3. To fix this issue and improve the debugging experience with PTDUMP, we redefine _PAGE_SPECIAL to its original value and use _PAGE_SOFT as the RSW mask, allow it to print the RSW with any non-zero value. This patch also removes the val from the struct prot_bits as it is no longer needed. Signed-off-by: Yu Chien Peter Lin <peterlin@andestech.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20230921025022.3989723-2-peterlin@andestech.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-09-21 10:50:20 +08:00
#define _PAGE_SOFT (3 << 8) /* Reserved for software */
RISC-V: Paging and MMU This patch contains code to manage the RISC-V MMU, including definitions of the page tables and the page walking code. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:06:09 -07:00
riscv: Improve PTDUMP to show RSW with non-zero value RSW field can be used to encode 2 bits of software defined information. Currently, PTDUMP only prints "RSW" when its value is 1 or 3. To fix this issue and improve the debugging experience with PTDUMP, we redefine _PAGE_SPECIAL to its original value and use _PAGE_SOFT as the RSW mask, allow it to print the RSW with any non-zero value. This patch also removes the val from the struct prot_bits as it is no longer needed. Signed-off-by: Yu Chien Peter Lin <peterlin@andestech.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20230921025022.3989723-2-peterlin@andestech.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-09-21 10:50:20 +08:00
#define _PAGE_SPECIAL (1 << 8) /* RSW: 0x1 */
RISC-V: Paging and MMU This patch contains code to manage the RISC-V MMU, including definitions of the page tables and the page walking code. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:06:09 -07:00
#define _PAGE_TABLE _PAGE_PRESENT
riscv: Add pte bit to distinguish swap from invalid Previously, invalid PTEs and swap PTEs had the same binary representation, causing errors when attempting to unmap PROT_NONE mappings, including implicit unmap on exit. Typical error: swap_info_get: Bad swap file entry 40000000007a9879 BUG: Bad page map in process a.out pte:3d4c3cc0 pmd:3e521401 Cc: stable@vger.kernel.org Signed-off-by: Stefan O'Rear <sorear2@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-12-16 13:03:36 -05:00
/*
* _PAGE_PROT_NONE is set on not-present pages (and ignored by the hardware) to
* distinguish them from swapped out pages
*/
riscv/mm: Adjust PAGE_PROT_NONE to comply with THP semantics This is a preparation for enabling THP migration. As the commit b65399f6111b("arm64/mm: Change THP helpers to comply with generic MM semantics") mentioned, pmd_present() and pmd_trans_huge() are expected to behave in the following manner: ------------------------------------------------------------------------- | PMD states | pmd_present | pmd_trans_huge | ------------------------------------------------------------------------- | Mapped | Yes | Yes | ------------------------------------------------------------------------- | Splitting | Yes | Yes | ------------------------------------------------------------------------- | Migration/Swap | No | No | ------------------------------------------------------------------------- At present the PROT_NONE bit reuses the READ bit could not comply with above semantics with two problems: 1. When splitting a PMD THP, PMD is first invalidated with pmdp_invalidate()->pmd_mkinvalid(), which clears the PRESENT bit and PROT_NONE bit/READ bit, if the PMD is read-only, then the PAGE_LEAF property is also cleared, which results in pmd_present() return false. 2. When migrating, the swap entry only clear the PRESENT bit and PROT_NONE bit/READ bit, the W/X bit may be set, so _PAGE_LEAF may be true which results in pmd_present() return true. Solution: Adjust PROT_NONE bit from READ to GLOBAL bit can satisfy the above rules: 1. GLOBAL bit has no other meanings, not like the R/W/X bit, which is also relative with _PAGE_LEAF property. 2. GLOBAL bit is at bit 5, making swap entry start from bit 6, bit 0-5 are zero, which means the PRESENT, PROT_NONE, and PAGE_LEAF are all false, then the pmd_present() and pmd_trans_huge() return false when in migration/swap. Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2021-11-23 22:06:37 +08:00
#define _PAGE_PROT_NONE _PAGE_GLOBAL
riscv: Add pte bit to distinguish swap from invalid Previously, invalid PTEs and swap PTEs had the same binary representation, causing errors when attempting to unmap PROT_NONE mappings, including implicit unmap on exit. Typical error: swap_info_get: Bad swap file entry 40000000007a9879 BUG: Bad page map in process a.out pte:3d4c3cc0 pmd:3e521401 Cc: stable@vger.kernel.org Signed-off-by: Stefan O'Rear <sorear2@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-12-16 13:03:36 -05:00
riscv/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the offset. This reduces the maximum swap space per file: on 32bit to 16 GiB (was 32 GiB). Note that this bit does not conflict with swap PMDs and could also be used in swap PMD context later. While at it, mask the type in __swp_entry(). Link: https://lkml.kernel.org/r/20230113171026.582290-20-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-13 18:10:19 +01:00
/* Used for swap PTEs only. */
#define _PAGE_SWP_EXCLUSIVE _PAGE_ACCESSED
RISC-V: Paging and MMU This patch contains code to manage the RISC-V MMU, including definitions of the page tables and the page walking code. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:06:09 -07:00
#define _PAGE_PFN_SHIFT 10
riscv: mm: add _PAGE_LEAF macro In riscv, a page table entry is leaf when any bit of read, write, or execute bit is set. So add a macro:_PAGE_LEAF instead of (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC), which is frequently used to determine if it is a leaf page. This make code easier to read, without any functional change. Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-30 16:28:47 +08:00
/*
* when all of R/W/X are zero, the PTE is a pointer to the next level
* of the page table; otherwise, it is a leaf PTE.
*/
#define _PAGE_LEAF (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC)
RISC-V: Paging and MMU This patch contains code to manage the RISC-V MMU, including definitions of the page tables and the page walking code. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-07-10 18:06:09 -07:00
#endif /* _ASM_RISCV_PGTABLE_BITS_H */
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