[PATCH v7 4/4] RISC-V: Add arch functions to support hibernation/suspend-to-disk
Andrew Jones
ajones at ventanamicro.com
Mon Mar 27 06:10:25 PDT 2023
On Thu, Mar 23, 2023 at 12:56:04PM +0800, Sia Jee Heng wrote:
> 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_ARCH_HIBERNATION_HEADER
> - CONFIG_ARCH_HIBERNATION_POSSIBLE
>
> Signed-off-by: Sia Jee Heng <jeeheng.sia at starfivetech.com>
> Reviewed-by: Ley Foon Tan <leyfoon.tan at starfivetech.com>
> Reviewed-by: Mason Huo <mason.huo at starfivetech.com>
> Reviewed-by: Conor Dooley <conor.dooley at microchip.com>
> ---
> arch/riscv/Kconfig | 6 +
> arch/riscv/include/asm/assembler.h | 20 ++
> arch/riscv/include/asm/suspend.h | 19 ++
> arch/riscv/kernel/Makefile | 1 +
> arch/riscv/kernel/asm-offsets.c | 5 +
> arch/riscv/kernel/hibernate-asm.S | 77 ++++++
> arch/riscv/kernel/hibernate.c | 427 +++++++++++++++++++++++++++++
> 7 files changed, 555 insertions(+)
> create mode 100644 arch/riscv/kernel/hibernate-asm.S
> create mode 100644 arch/riscv/kernel/hibernate.c
>
Reviewed-by: Andrew Jones <ajones at ventanamicro.com>
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