linux-stable/arch/riscv/include/asm/assembler.h
Sia Jee Heng c031721001
RISC-V: Add arch functions to support hibernation/suspend-to-disk
Low level Arch functions were created to support hibernation.
swsusp_arch_suspend() relies code from __cpu_suspend_enter() to write
cpu state onto the stack, then calling swsusp_save() to save the memory
image.

Arch specific hibernation header is implemented and is utilized by the
arch_hibernation_header_restore() and arch_hibernation_header_save()
functions. The arch specific hibernation header consists of satp, hartid,
and the cpu_resume address. The kernel built version is also need to be
saved into the hibernation image header to making sure only the same
kernel is restore when resume.

swsusp_arch_resume() creates a temporary page table that covering only
the linear map. It copies the restore code to a 'safe' page, then start
to restore the memory image. Once completed, it restores the original
kernel's page table. It then calls into __hibernate_cpu_resume()
to restore the CPU context. Finally, it follows the normal hibernation
path back to the hibernation core.

To enable hibernation/suspend to disk into RISCV, the below config
need to be enabled:
- CONFIG_HIBERNATION
- CONFIG_ARCH_HIBERNATION_HEADER
- CONFIG_ARCH_HIBERNATION_POSSIBLE

Signed-off-by: Sia Jee Heng <jeeheng.sia@starfivetech.com>
Reviewed-by: Ley Foon Tan <leyfoon.tan@starfivetech.com>
Reviewed-by: Mason Huo <mason.huo@starfivetech.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20230330064321.1008373-5-jeeheng.sia@starfivetech.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-29 11:25:13 -07:00

82 lines
2.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2023 StarFive Technology Co., Ltd.
*
* Author: Jee Heng Sia <jeeheng.sia@starfivetech.com>
*/
#ifndef __ASSEMBLY__
#error "Only include this from assembly code"
#endif
#ifndef __ASM_ASSEMBLER_H
#define __ASM_ASSEMBLER_H
#include <asm/asm.h>
#include <asm/asm-offsets.h>
#include <asm/csr.h>
/*
* suspend_restore_csrs - restore CSRs
*/
.macro suspend_restore_csrs
REG_L t0, (SUSPEND_CONTEXT_REGS + PT_EPC)(a0)
csrw CSR_EPC, t0
REG_L t0, (SUSPEND_CONTEXT_REGS + PT_STATUS)(a0)
csrw CSR_STATUS, t0
REG_L t0, (SUSPEND_CONTEXT_REGS + PT_BADADDR)(a0)
csrw CSR_TVAL, t0
REG_L t0, (SUSPEND_CONTEXT_REGS + PT_CAUSE)(a0)
csrw CSR_CAUSE, t0
.endm
/*
* suspend_restore_regs - Restore registers (except A0 and T0-T6)
*/
.macro suspend_restore_regs
REG_L ra, (SUSPEND_CONTEXT_REGS + PT_RA)(a0)
REG_L sp, (SUSPEND_CONTEXT_REGS + PT_SP)(a0)
REG_L gp, (SUSPEND_CONTEXT_REGS + PT_GP)(a0)
REG_L tp, (SUSPEND_CONTEXT_REGS + PT_TP)(a0)
REG_L s0, (SUSPEND_CONTEXT_REGS + PT_S0)(a0)
REG_L s1, (SUSPEND_CONTEXT_REGS + PT_S1)(a0)
REG_L a1, (SUSPEND_CONTEXT_REGS + PT_A1)(a0)
REG_L a2, (SUSPEND_CONTEXT_REGS + PT_A2)(a0)
REG_L a3, (SUSPEND_CONTEXT_REGS + PT_A3)(a0)
REG_L a4, (SUSPEND_CONTEXT_REGS + PT_A4)(a0)
REG_L a5, (SUSPEND_CONTEXT_REGS + PT_A5)(a0)
REG_L a6, (SUSPEND_CONTEXT_REGS + PT_A6)(a0)
REG_L a7, (SUSPEND_CONTEXT_REGS + PT_A7)(a0)
REG_L s2, (SUSPEND_CONTEXT_REGS + PT_S2)(a0)
REG_L s3, (SUSPEND_CONTEXT_REGS + PT_S3)(a0)
REG_L s4, (SUSPEND_CONTEXT_REGS + PT_S4)(a0)
REG_L s5, (SUSPEND_CONTEXT_REGS + PT_S5)(a0)
REG_L s6, (SUSPEND_CONTEXT_REGS + PT_S6)(a0)
REG_L s7, (SUSPEND_CONTEXT_REGS + PT_S7)(a0)
REG_L s8, (SUSPEND_CONTEXT_REGS + PT_S8)(a0)
REG_L s9, (SUSPEND_CONTEXT_REGS + PT_S9)(a0)
REG_L s10, (SUSPEND_CONTEXT_REGS + PT_S10)(a0)
REG_L s11, (SUSPEND_CONTEXT_REGS + PT_S11)(a0)
.endm
/*
* copy_page - copy 1 page (4KB) of data from source to destination
* @a0 - destination
* @a1 - source
*/
.macro copy_page a0, a1
lui a2, 0x1
add a2, a2, a0
1 :
REG_L t0, 0(a1)
REG_L t1, SZREG(a1)
REG_S t0, 0(a0)
REG_S t1, SZREG(a0)
addi a0, a0, 2 * SZREG
addi a1, a1, 2 * SZREG
bne a2, a0, 1b
.endm
#endif /* __ASM_ASSEMBLER_H */