/* 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_PGTABLE_LEVELS		(CONFIG_PGTABLE_LEVELS - SWAPPER_SKIP_LEVEL)#define INIT_IDMAP_PGTABLE_LEVELS	(IDMAP_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(lvl, vstart, vend) \	SPAN_NR_ENTRIES(vstart, vend, SWAPPER_BLOCK_SHIFT + lvl * PTDESC_TABLE_SHIFT) #define EARLY_LEVEL(lvl, lvls, vstart, vend, add) \	((lvls) > (lvl) ? EARLY_ENTRIES(lvl, vstart, vend) + (add) : 0) #define EARLY_PAGES(lvls, vstart, vend, add) (1 	/* PGDIR page */				\	+ EARLY_LEVEL(3, (lvls), (vstart), (vend), add) /* each entry needs a next level page table */	\	+ EARLY_LEVEL(2, (lvls), (vstart), (vend), add)	/* each entry needs a next level page table */	\	+ EARLY_LEVEL(1, (lvls), (vstart), (vend), add))/* each entry needs a next level page table */#define INIT_DIR_SIZE (PAGE_SIZE * (EARLY_PAGES(SWAPPER_PGTABLE_LEVELS, KIMAGE_VADDR, _end, EXTRA_PAGE) \				    + EARLY_SEGMENT_EXTRA_PAGES)) #define INIT_IDMAP_DIR_PAGES	(EARLY_PAGES(INIT_IDMAP_PGTABLE_LEVELS, KIMAGE_VADDR, kimage_limit, 1))#define INIT_IDMAP_DIR_SIZE	((INIT_IDMAP_DIR_PAGES + EARLY_IDMAP_EXTRA_PAGES) * PAGE_SIZE) #define INIT_IDMAP_FDT_PAGES	(EARLY_PAGES(INIT_IDMAP_PGTABLE_LEVELS, 0UL, UL(MAX_FDT_SIZE), 1) - 1)#define INIT_IDMAP_FDT_SIZE	((INIT_IDMAP_FDT_PAGES + EARLY_IDMAP_EXTRA_FDT_PAGES) * PAGE_SIZE) /* 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/* * KERNEL_SEGMENT_COUNT counts the permanent kernel VMAs. The early mapping * has one additional split, [_text, _stext). Reserve one more page for the * SWAPPER_BLOCK_SIZE-unaligned boundaries. */#define EARLY_SEGMENT_EXTRA_PAGES (KERNEL_SEGMENT_COUNT + 2)/* * The initial ID map consists of the kernel image, mapped as two separate * segments, and may appear misaligned wrt the swapper block size. This means * we need 3 additional pages. The DT could straddle a swapper block boundary, * so it may need 2. */#define EARLY_IDMAP_EXTRA_PAGES		3#define EARLY_IDMAP_EXTRA_FDT_PAGES	2#else#define EARLY_SEGMENT_EXTRA_PAGES	0#define EARLY_IDMAP_EXTRA_PAGES		0#define EARLY_IDMAP_EXTRA_FDT_PAGES	0#endif #endif	/* __ASM_KERNEL_PGTABLE_H */