146 lines
5.1 KiB
C
146 lines
5.1 KiB
C
|
/* 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 linear mapping and the start of memory are both 2M aligned (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).
|
||
|
|
*/
|
||
|
|
|
||
|
|
/*
|
||
|
|
* The idmap and swapper page tables need some space reserved in the kernel
|
||
|
|
* image. Both require pgd, pud (4 levels only) and pmd tables to (section)
|
||
|
|
* map the kernel. With the 64K page configuration, swapper and idmap need to
|
||
|
|
* map to pte level. The swapper also maps the FDT (see __create_page_tables
|
||
|
|
* for more information). Note that the number of ID map translation levels
|
||
|
|
* could be increased on the fly if system RAM is out of reach for the default
|
||
|
|
* VA range, so pages required to map highest possible PA are reserved in all
|
||
|
|
* cases.
|
||
|
|
*/
|
||
|
|
#ifdef CONFIG_ARM64_4K_PAGES
|
||
|
|
#define SWAPPER_PGTABLE_LEVELS (CONFIG_PGTABLE_LEVELS - 1)
|
||
|
|
#else
|
||
|
|
#define SWAPPER_PGTABLE_LEVELS (CONFIG_PGTABLE_LEVELS)
|
||
|
|
#endif
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
* If KASLR is enabled, then an offset K is added to the kernel address
|
||
|
|
* space. The bottom 21 bits of this offset are zero to guarantee 2MB
|
||
|
|
* alignment for PA and VA.
|
||
|
|
*
|
||
|
|
* For each pagetable level of the swapper, we know that the shift will
|
||
|
|
* be larger than 21 (for the 4KB granule case we use section maps thus
|
||
|
|
* the smallest shift is actually 30) thus there is the possibility that
|
||
|
|
* KASLR can increase the number of pagetable entries by 1, so we make
|
||
|
|
* room for this extra entry.
|
||
|
|
*
|
||
|
|
* Note KASLR cannot increase the number of required entries for a level
|
||
|
|
* by more than one because it increments both the virtual start and end
|
||
|
|
* addresses equally (the extra entry comes from the case where the end
|
||
|
|
* address is just pushed over a boundary and the start address isn't).
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifdef CONFIG_RANDOMIZE_BASE
|
||
|
|
#define EARLY_KASLR (1)
|
||
|
|
#else
|
||
|
|
#define EARLY_KASLR (0)
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#define EARLY_ENTRIES(vstart, vend, shift, add) \
|
||
|
|
((((vend) - 1) >> (shift)) - ((vstart) >> (shift)) + 1 + add)
|
||
|
|
|
||
|
|
#define EARLY_PGDS(vstart, vend, add) (EARLY_ENTRIES(vstart, vend, PGDIR_SHIFT, add))
|
||
|
|
|
||
|
|
#if SWAPPER_PGTABLE_LEVELS > 3
|
||
|
|
#define EARLY_PUDS(vstart, vend, add) (EARLY_ENTRIES(vstart, vend, PUD_SHIFT, add))
|
||
|
|
#else
|
||
|
|
#define EARLY_PUDS(vstart, vend, add) (0)
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#if SWAPPER_PGTABLE_LEVELS > 2
|
||
|
|
#define EARLY_PMDS(vstart, vend, add) (EARLY_ENTRIES(vstart, vend, SWAPPER_TABLE_SHIFT, add))
|
||
|
|
#else
|
||
|
|
#define EARLY_PMDS(vstart, vend, add) (0)
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#define EARLY_PAGES(vstart, vend, add) ( 1 /* PGDIR page */ \
|
||
|
|
+ EARLY_PGDS((vstart), (vend), add) /* each PGDIR needs a next level page table */ \
|
||
|
|
+ EARLY_PUDS((vstart), (vend), add) /* each PUD needs a next level page table */ \
|
||
|
|
+ EARLY_PMDS((vstart), (vend), add)) /* each PMD needs a next level page table */
|
||
|
|
#define INIT_DIR_SIZE (PAGE_SIZE * EARLY_PAGES(KIMAGE_VADDR, _end, EARLY_KASLR))
|
||
|
|
|
||
|
|
/* 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)
|
||
|
|
|
||
|
|
/* Initial memory map size */
|
||
|
|
#ifdef CONFIG_ARM64_4K_PAGES
|
||
|
|
#define SWAPPER_BLOCK_SHIFT PMD_SHIFT
|
||
|
|
#define SWAPPER_BLOCK_SIZE PMD_SIZE
|
||
|
|
#define SWAPPER_TABLE_SHIFT PUD_SHIFT
|
||
|
|
#else
|
||
|
|
#define SWAPPER_BLOCK_SHIFT PAGE_SHIFT
|
||
|
|
#define SWAPPER_BLOCK_SIZE PAGE_SIZE
|
||
|
|
#define SWAPPER_TABLE_SHIFT PMD_SHIFT
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Initial memory map attributes.
|
||
|
|
*/
|
||
|
|
#define SWAPPER_PTE_FLAGS (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED)
|
||
|
|
#define SWAPPER_PMD_FLAGS (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S)
|
||
|
|
|
||
|
|
#ifdef CONFIG_ARM64_4K_PAGES
|
||
|
|
#define SWAPPER_RW_MMUFLAGS (PMD_ATTRINDX(MT_NORMAL) | SWAPPER_PMD_FLAGS)
|
||
|
|
#define SWAPPER_RX_MMUFLAGS (SWAPPER_RW_MMUFLAGS | PMD_SECT_RDONLY)
|
||
|
|
#else
|
||
|
|
#define SWAPPER_RW_MMUFLAGS (PTE_ATTRINDX(MT_NORMAL) | SWAPPER_PTE_FLAGS)
|
||
|
|
#define SWAPPER_RX_MMUFLAGS (SWAPPER_RW_MMUFLAGS | PTE_RDONLY)
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/*
|
||
|
|
* To make optimal use of block mappings when laying out the linear
|
||
|
|
* mapping, round down the base of physical memory to a size that can
|
||
|
|
* be mapped efficiently, i.e., either PUD_SIZE (4k granule) or PMD_SIZE
|
||
|
|
* (64k granule), or a multiple that can be mapped using contiguous bits
|
||
|
|
* in the page tables: 32 * PMD_SIZE (16k granule)
|
||
|
|
*/
|
||
|
|
#if defined(CONFIG_ARM64_4K_PAGES)
|
||
|
|
#define ARM64_MEMSTART_SHIFT PUD_SHIFT
|
||
|
|
#elif defined(CONFIG_ARM64_16K_PAGES)
|
||
|
|
#define ARM64_MEMSTART_SHIFT CONT_PMD_SHIFT
|
||
|
|
#else
|
||
|
|
#define ARM64_MEMSTART_SHIFT PMD_SHIFT
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/*
|
||
|
|
* sparsemem vmemmap imposes an additional requirement on the alignment of
|
||
|
|
* memstart_addr, due to the fact that the base of the vmemmap region
|
||
|
|
* has a direct correspondence, and needs to appear sufficiently aligned
|
||
|
|
* in the virtual address space.
|
||
|
|
*/
|
||
|
|
#if ARM64_MEMSTART_SHIFT < SECTION_SIZE_BITS
|
||
|
|
#define ARM64_MEMSTART_ALIGN (1UL << SECTION_SIZE_BITS)
|
||
|
|
#else
|
||
|
|
#define ARM64_MEMSTART_ALIGN (1UL << ARM64_MEMSTART_SHIFT)
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#endif /* __ASM_KERNEL_PGTABLE_H */
|