Commit 4f04d8f0 authored by Catalin Marinas's avatar Catalin Marinas

arm64: MMU definitions

The virtual memory layout is described in
Documentation/arm64/memory.txt. This patch adds the MMU definitions for
the 4KB and 64KB translation table configurations. The SECTION_SIZE is
2MB with 4KB page and 512MB with 64KB page configuration.

PHYS_OFFSET is calculated at run-time and stored in a variable (no
run-time code patching at this stage).

On the current implementation, both user and kernel address spaces are
512G (39-bit) each with a maximum of 256G for the RAM linear mapping.
Linux uses 3 levels of translation tables with the 4K page configuration
and 2 levels with the 64K configuration. Extending the memory space
beyond 39-bit with the 4K pages or 42-bit with 64K pages requires an
additional level of translation tables.

The SPARSEMEM configuration is global to all AArch64 platforms and
allows for 1GB sections with SPARSEMEM_VMEMMAP enabled by default.
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Acked-by: default avatarTony Lindgren <tony@atomide.com>
Acked-by: default avatarNicolas Pitre <nico@linaro.org>
Acked-by: default avatarOlof Johansson <olof@lixom.net>
Acked-by: default avatarSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
parent 60ffc30d
Memory Layout on AArch64 Linux
==============================
Author: Catalin Marinas <catalin.marinas@arm.com>
Date : 20 February 2012
This document describes the virtual memory layout used by the AArch64
Linux kernel. The architecture allows up to 4 levels of translation
tables with a 4KB page size and up to 3 levels with a 64KB page size.
AArch64 Linux uses 3 levels of translation tables with the 4KB page
configuration, allowing 39-bit (512GB) virtual addresses for both user
and kernel. With 64KB pages, only 2 levels of translation tables are
used but the memory layout is the same.
User addresses have bits 63:39 set to 0 while the kernel addresses have
the same bits set to 1. TTBRx selection is given by bit 63 of the
virtual address. The swapper_pg_dir contains only kernel (global)
mappings while the user pgd contains only user (non-global) mappings.
The swapper_pgd_dir address is written to TTBR1 and never written to
TTBR0.
AArch64 Linux memory layout:
Start End Size Use
-----------------------------------------------------------------------
0000000000000000 0000007fffffffff 512GB user
ffffff8000000000 ffffffbbfffcffff ~240GB vmalloc
ffffffbbfffd0000 ffffffbcfffdffff 64KB [guard page]
ffffffbbfffe0000 ffffffbcfffeffff 64KB PCI I/O space
ffffffbbffff0000 ffffffbcffffffff 64KB [guard page]
ffffffbc00000000 ffffffbdffffffff 8GB vmemmap
ffffffbe00000000 ffffffbffbffffff ~8GB [guard, future vmmemap]
ffffffbffc000000 ffffffbfffffffff 64MB modules
ffffffc000000000 ffffffffffffffff 256GB memory
Translation table lookup with 4KB pages:
+--------+--------+--------+--------+--------+--------+--------+--------+
|63 56|55 48|47 40|39 32|31 24|23 16|15 8|7 0|
+--------+--------+--------+--------+--------+--------+--------+--------+
| | | | | |
| | | | | v
| | | | | [11:0] in-page offset
| | | | +-> [20:12] L3 index
| | | +-----------> [29:21] L2 index
| | +---------------------> [38:30] L1 index
| +-------------------------------> [47:39] L0 index (not used)
+-------------------------------------------------> [63] TTBR0/1
Translation table lookup with 64KB pages:
+--------+--------+--------+--------+--------+--------+--------+--------+
|63 56|55 48|47 40|39 32|31 24|23 16|15 8|7 0|
+--------+--------+--------+--------+--------+--------+--------+--------+
| | | | |
| | | | v
| | | | [15:0] in-page offset
| | | +----------> [28:16] L3 index
| | +--------------------------> [41:29] L2 index (only 38:29 used)
| +-------------------------------> [47:42] L1 index (not used)
+-------------------------------------------------> [63] TTBR0/1
/*
* Based on arch/arm/include/asm/memory.h
*
* Copyright (C) 2000-2002 Russell King
* 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/>.
*
* Note: this file should not be included by non-asm/.h files
*/
#ifndef __ASM_MEMORY_H
#define __ASM_MEMORY_H
#include <linux/compiler.h>
#include <linux/const.h>
#include <linux/types.h>
#include <asm/sizes.h>
/*
* Allow for constants defined here to be used from assembly code
* by prepending the UL suffix only with actual C code compilation.
*/
#define UL(x) _AC(x, UL)
/*
* PAGE_OFFSET - the virtual address of the start of the kernel image.
* VA_BITS - the maximum number of bits for virtual addresses.
* TASK_SIZE - the maximum size of a user space task.
* TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
* The module space lives between the addresses given by TASK_SIZE
* and PAGE_OFFSET - it must be within 128MB of the kernel text.
*/
#define PAGE_OFFSET UL(0xffffffc000000000)
#define MODULES_END (PAGE_OFFSET)
#define MODULES_VADDR (MODULES_END - SZ_64M)
#define VA_BITS (39)
#define TASK_SIZE_64 (UL(1) << VA_BITS)
#ifdef CONFIG_COMPAT
#define TASK_SIZE_32 UL(0x100000000)
#define TASK_SIZE (test_thread_flag(TIF_32BIT) ? \
TASK_SIZE_32 : TASK_SIZE_64)
#else
#define TASK_SIZE TASK_SIZE_64
#endif /* CONFIG_COMPAT */
#define TASK_UNMAPPED_BASE (PAGE_ALIGN(TASK_SIZE / 4))
#if TASK_SIZE_64 > MODULES_VADDR
#error Top of 64-bit user space clashes with start of module space
#endif
/*
* Physical vs virtual RAM address space conversion. These are
* private definitions which should NOT be used outside memory.h
* files. Use virt_to_phys/phys_to_virt/__pa/__va instead.
*/
#define __virt_to_phys(x) (((phys_addr_t)(x) - PAGE_OFFSET + PHYS_OFFSET))
#define __phys_to_virt(x) ((unsigned long)((x) - PHYS_OFFSET + PAGE_OFFSET))
/*
* Convert a physical address to a Page Frame Number and back
*/
#define __phys_to_pfn(paddr) ((unsigned long)((paddr) >> PAGE_SHIFT))
#define __pfn_to_phys(pfn) ((phys_addr_t)(pfn) << PAGE_SHIFT)
/*
* Convert a page to/from a physical address
*/
#define page_to_phys(page) (__pfn_to_phys(page_to_pfn(page)))
#define phys_to_page(phys) (pfn_to_page(__phys_to_pfn(phys)))
/*
* Memory types available.
*/
#define MT_DEVICE_nGnRnE 0
#define MT_DEVICE_nGnRE 1
#define MT_DEVICE_GRE 2
#define MT_NORMAL_NC 3
#define MT_NORMAL 4
#ifndef __ASSEMBLY__
extern phys_addr_t memstart_addr;
/* PHYS_OFFSET - the physical address of the start of memory. */
#define PHYS_OFFSET ({ memstart_addr; })
/*
* PFNs are used to describe any physical page; this means
* PFN 0 == physical address 0.
*
* This is the PFN of the first RAM page in the kernel
* direct-mapped view. We assume this is the first page
* of RAM in the mem_map as well.
*/
#define PHYS_PFN_OFFSET (PHYS_OFFSET >> PAGE_SHIFT)
/*
* Note: Drivers should NOT use these. They are the wrong
* translation for translating DMA addresses. Use the driver
* DMA support - see dma-mapping.h.
*/
static inline phys_addr_t virt_to_phys(const volatile void *x)
{
return __virt_to_phys((unsigned long)(x));
}
static inline void *phys_to_virt(phys_addr_t x)
{
return (void *)(__phys_to_virt(x));
}
/*
* Drivers should NOT use these either.
*/
#define __pa(x) __virt_to_phys((unsigned long)(x))
#define __va(x) ((void *)__phys_to_virt((phys_addr_t)(x)))
#define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
/*
* virt_to_page(k) convert a _valid_ virtual address to struct page *
* virt_addr_valid(k) indicates whether a virtual address is valid
*/
#define ARCH_PFN_OFFSET PHYS_PFN_OFFSET
#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
#define virt_addr_valid(kaddr) (((void *)(kaddr) >= (void *)PAGE_OFFSET) && \
((void *)(kaddr) < (void *)high_memory))
#endif
#include <asm-generic/memory_model.h>
#endif
/*
* 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_MMU_H
#define __ASM_MMU_H
typedef struct {
unsigned int id;
raw_spinlock_t id_lock;
void *vdso;
} mm_context_t;
#define ASID(mm) ((mm)->context.id & 0xffff)
extern void paging_init(void);
extern void setup_mm_for_reboot(void);
#endif
/*
* 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_2LEVEL_HWDEF_H
#define __ASM_PGTABLE_2LEVEL_HWDEF_H
/*
* With LPAE and 64KB pages, there are 2 levels of page tables. Each level has
* 8192 entries of 8 bytes each, occupying a 64KB page. Levels 0 and 1 are not
* used. The 2nd level table (PGD for Linux) can cover a range of 4TB, each
* entry representing 512MB. The user and kernel address spaces are limited to
* 512GB and therefore we only use 1024 entries in the PGD.
*/
#define PTRS_PER_PTE 8192
#define PTRS_PER_PGD 1024
/*
* PGDIR_SHIFT determines the size a top-level page table entry can map.
*/
#define PGDIR_SHIFT 29
#define PGDIR_SIZE (_AC(1, UL) << PGDIR_SHIFT)
#define PGDIR_MASK (~(PGDIR_SIZE-1))
/*
* section address mask and size definitions.
*/
#define SECTION_SHIFT 29
#define SECTION_SIZE (_AC(1, UL) << SECTION_SHIFT)
#define SECTION_MASK (~(SECTION_SIZE-1))
#endif
/*
* 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_2LEVEL_TYPES_H
#define __ASM_PGTABLE_2LEVEL_TYPES_H
typedef u64 pteval_t;
typedef u64 pgdval_t;
typedef pgdval_t pmdval_t;
#undef STRICT_MM_TYPECHECKS
#ifdef STRICT_MM_TYPECHECKS
/*
* These are used to make use of C type-checking..
*/
typedef struct { pteval_t pte; } pte_t;
typedef struct { pgdval_t pgd; } pgd_t;
typedef struct { pteval_t pgprot; } pgprot_t;
#define pte_val(x) ((x).pte)
#define pgd_val(x) ((x).pgd)
#define pgprot_val(x) ((x).pgprot)
#define __pte(x) ((pte_t) { (x) } )
#define __pgd(x) ((pgd_t) { (x) } )
#define __pgprot(x) ((pgprot_t) { (x) } )
#else /* !STRICT_MM_TYPECHECKS */
typedef pteval_t pte_t;
typedef pgdval_t pgd_t;
typedef pteval_t pgprot_t;
#define pte_val(x) (x)
#define pgd_val(x) (x)
#define pgprot_val(x) (x)
#define __pte(x) (x)
#define __pgd(x) (x)
#define __pgprot(x) (x)
#endif /* STRICT_MM_TYPECHECKS */
#include <asm-generic/pgtable-nopmd.h>
#endif /* __ASM_PGTABLE_2LEVEL_TYPES_H */
/*
* 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_3LEVEL_HWDEF_H
#define __ASM_PGTABLE_3LEVEL_HWDEF_H
/*
* With LPAE and 4KB pages, there are 3 levels of page tables. Each level has
* 512 entries of 8 bytes each, occupying a 4K page. The first level table
* covers a range of 512GB, each entry representing 1GB. The user and kernel
* address spaces are limited to 512GB each.
*/
#define PTRS_PER_PTE 512
#define PTRS_PER_PMD 512
#define PTRS_PER_PGD 512
/*
* PGDIR_SHIFT determines the size a top-level page table entry can map.
*/
#define PGDIR_SHIFT 30
#define PGDIR_SIZE (_AC(1, UL) << PGDIR_SHIFT)
#define PGDIR_MASK (~(PGDIR_SIZE-1))
/*
* PMD_SHIFT determines the size a middle-level page table entry can map.
*/
#define PMD_SHIFT 21
#define PMD_SIZE (_AC(1, UL) << PMD_SHIFT)
#define PMD_MASK (~(PMD_SIZE-1))
/*
* section address mask and size definitions.
*/
#define SECTION_SHIFT 21
#define SECTION_SIZE (_AC(1, UL) << SECTION_SHIFT)
#define SECTION_MASK (~(SECTION_SIZE-1))
#endif
/*
* 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_3LEVEL_TYPES_H
#define __ASM_PGTABLE_3LEVEL_TYPES_H
typedef u64 pteval_t;
typedef u64 pmdval_t;
typedef u64 pgdval_t;
#undef STRICT_MM_TYPECHECKS
#ifdef STRICT_MM_TYPECHECKS
/*
* These are used to make use of C type-checking..
*/
typedef struct { pteval_t pte; } pte_t;
typedef struct { pmdval_t pmd; } pmd_t;
typedef struct { pgdval_t pgd; } pgd_t;
typedef struct { pteval_t pgprot; } pgprot_t;
#define pte_val(x) ((x).pte)
#define pmd_val(x) ((x).pmd)
#define pgd_val(x) ((x).pgd)
#define pgprot_val(x) ((x).pgprot)
#define __pte(x) ((pte_t) { (x) } )
#define __pmd(x) ((pmd_t) { (x) } )
#define __pgd(x) ((pgd_t) { (x) } )
#define __pgprot(x) ((pgprot_t) { (x) } )
#else /* !STRICT_MM_TYPECHECKS */
typedef pteval_t pte_t;
typedef pmdval_t pmd_t;
typedef pgdval_t pgd_t;
typedef pteval_t pgprot_t;
#define pte_val(x) (x)
#define pmd_val(x) (x)
#define pgd_val(x) (x)
#define pgprot_val(x) (x)
#define __pte(x) (x)
#define __pmd(x) (x)
#define __pgd(x) (x)
#define __pgprot(x) (x)
#endif /* STRICT_MM_TYPECHECKS */
#include <asm-generic/pgtable-nopud.h>
#endif /* __ASM_PGTABLE_3LEVEL_TYPES_H */
/*
* 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_XN (_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_XN (_AT(pteval_t, 1) << 54) /* 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
This diff is collapsed.
/*
* 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_SPARSEMEM_H
#define __ASM_SPARSEMEM_H
#ifdef CONFIG_SPARSEMEM
#define MAX_PHYSMEM_BITS 40
#define SECTION_SIZE_BITS 30
#endif
#endif
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment