linux-stable/arch/riscv/include/asm/kasan.h
Alexandre Ghiti e8a62cc26d
riscv: Implement sv48 support
By adding a new 4th level of page table, give the possibility to 64bit
kernel to address 2^48 bytes of virtual address: in practice, that offers
128TB of virtual address space to userspace and allows up to 64TB of
physical memory.

If the underlying hardware does not support sv48, we will automatically
fallback to a standard 3-level page table by folding the new PUD level into
PGDIR level. In order to detect HW capabilities at runtime, we
use SATP feature that ignores writes with an unsupported mode.

Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-01-19 17:54:09 -08:00

45 lines
1.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (C) 2019 Andes Technology Corporation */
#ifndef __ASM_KASAN_H
#define __ASM_KASAN_H
#ifndef __ASSEMBLY__
#ifdef CONFIG_KASAN
/*
* The following comment was copied from arm64:
* KASAN_SHADOW_START: beginning of the kernel virtual addresses.
* KASAN_SHADOW_END: KASAN_SHADOW_START + 1/N of kernel virtual addresses,
* where N = (1 << KASAN_SHADOW_SCALE_SHIFT).
*
* KASAN_SHADOW_OFFSET:
* This value is used to map an address to the corresponding shadow
* address by the following formula:
* shadow_addr = (address >> KASAN_SHADOW_SCALE_SHIFT) + KASAN_SHADOW_OFFSET
*
* (1 << (64 - KASAN_SHADOW_SCALE_SHIFT)) shadow addresses that lie in range
* [KASAN_SHADOW_OFFSET, KASAN_SHADOW_END) cover all 64-bits of virtual
* addresses. So KASAN_SHADOW_OFFSET should satisfy the following equation:
* KASAN_SHADOW_OFFSET = KASAN_SHADOW_END -
* (1ULL << (64 - KASAN_SHADOW_SCALE_SHIFT))
*/
#define KASAN_SHADOW_SCALE_SHIFT 3
#define KASAN_SHADOW_SIZE (UL(1) << ((VA_BITS - 1) - KASAN_SHADOW_SCALE_SHIFT))
/*
* Depending on the size of the virtual address space, the region may not be
* aligned on PGDIR_SIZE, so force its alignment to ease its population.
*/
#define KASAN_SHADOW_START ((KASAN_SHADOW_END - KASAN_SHADOW_SIZE) & PGDIR_MASK)
#define KASAN_SHADOW_END MODULES_LOWEST_VADDR
#define KASAN_SHADOW_OFFSET _AC(CONFIG_KASAN_SHADOW_OFFSET, UL)
void kasan_init(void);
asmlinkage void kasan_early_init(void);
void kasan_swapper_init(void);
#endif
#endif
#endif /* __ASM_KASAN_H */