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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Kernel page table mapping
*
* Copyright (C) 2015 ARM Ltd.
*/
#ifndef __ASM_KERNEL_PGTABLE_H
#define __ASM_KERNEL_PGTABLE_H
#include <asm/boot.h>
#include <asm/pgtable-hwdef.h>
#include <asm/sparsemem.h>
/*
* The physical and virtual addresses of the start of the kernel image are
* equal modulo 2 MiB (per the arm64 booting.txt requirements). Hence we can
* use section mapping with 4K (section size = 2M) but not with 16K (section
* size = 32M) or 64K (section size = 512M).
*/
#if defined(PMD_SIZE) && PMD_SIZE <= MIN_KIMG_ALIGN
#define SWAPPER_BLOCK_SHIFT PMD_SHIFT
#define SWAPPER_SKIP_LEVEL 1
#else
#define SWAPPER_BLOCK_SHIFT PAGE_SHIFT
#define SWAPPER_SKIP_LEVEL 0
#endif
#define SWAPPER_BLOCK_SIZE (UL(1) << SWAPPER_BLOCK_SHIFT)
#define SWAPPER_TABLE_SHIFT (SWAPPER_BLOCK_SHIFT + PAGE_SHIFT - 3)
#define SWAPPER_PGTABLE_LEVELS (CONFIG_PGTABLE_LEVELS - SWAPPER_SKIP_LEVEL)
#define IDMAP_VA_BITS 48
#define IDMAP_LEVELS ARM64_HW_PGTABLE_LEVELS(IDMAP_VA_BITS)
#define IDMAP_ROOT_LEVEL (4 - IDMAP_LEVELS)
/*
* A relocatable kernel may execute from an address that differs from the one at
* which it was linked. In the worst case, its runtime placement may intersect
* with two adjacent PGDIR entries, which means that an additional page table
* may be needed at each subordinate level.
*/
#define EXTRA_PAGE __is_defined(CONFIG_RELOCATABLE)
#define SPAN_NR_ENTRIES(vstart, vend, shift) \
((((vend) - 1) >> (shift)) - ((vstart) >> (shift)) + 1)
#define EARLY_ENTRIES(vstart, vend, shift, add) \
(SPAN_NR_ENTRIES(vstart, vend, shift) + (add))
#define EARLY_LEVEL(lvl, vstart, vend, add) \
(SWAPPER_PGTABLE_LEVELS > lvl ? EARLY_ENTRIES(vstart, vend, SWAPPER_BLOCK_SHIFT + lvl * (PAGE_SHIFT - 3), add) : 0)
#define EARLY_PAGES(vstart, vend, add) (1 /* PGDIR page */ \
+ EARLY_LEVEL(3, (vstart), (vend), add) /* each entry needs a next level page table */ \
+ EARLY_LEVEL(2, (vstart), (vend), add) /* each entry needs a next level page table */ \
+ EARLY_LEVEL(1, (vstart), (vend), add))/* each entry needs a next level page table */
#define INIT_DIR_SIZE (PAGE_SIZE * (EARLY_PAGES(KIMAGE_VADDR, _end, EXTRA_PAGE) + EARLY_SEGMENT_EXTRA_PAGES))
/* the initial ID map may need two extra pages if it needs to be extended */
#if VA_BITS < 48
#define INIT_IDMAP_DIR_SIZE ((INIT_IDMAP_DIR_PAGES + 2) * PAGE_SIZE)
#else
#define INIT_IDMAP_DIR_SIZE (INIT_IDMAP_DIR_PAGES * PAGE_SIZE)
#endif
#define INIT_IDMAP_DIR_PAGES EARLY_PAGES(KIMAGE_VADDR, _end + MAX_FDT_SIZE + SWAPPER_BLOCK_SIZE, 1)
/* The number of segments in the kernel image (text, rodata, inittext, initdata, data+bss) */
#define KERNEL_SEGMENT_COUNT 5
#if SWAPPER_BLOCK_SIZE > SEGMENT_ALIGN
#define EARLY_SEGMENT_EXTRA_PAGES (KERNEL_SEGMENT_COUNT + 1)
#else
#define EARLY_SEGMENT_EXTRA_PAGES 0
#endif
/*
* Initial memory map attributes.
*/
#define SWAPPER_PTE_FLAGS (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED | PTE_UXN)
#define SWAPPER_PMD_FLAGS (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S | PTE_UXN)
#ifdef CONFIG_ARM64_4K_PAGES
#define SWAPPER_RW_MMUFLAGS (PMD_ATTRINDX(MT_NORMAL) | SWAPPER_PMD_FLAGS | PTE_WRITE)
#define SWAPPER_RX_MMUFLAGS (SWAPPER_RW_MMUFLAGS | PMD_SECT_RDONLY)
#else
#define SWAPPER_RW_MMUFLAGS (PTE_ATTRINDX(MT_NORMAL) | SWAPPER_PTE_FLAGS | PTE_WRITE)
#define SWAPPER_RX_MMUFLAGS (SWAPPER_RW_MMUFLAGS | PTE_RDONLY)
#endif
#endif /* __ASM_KERNEL_PGTABLE_H */
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