[PATCH 0/3] RISC-V Hibernation Support

[Conor Dooley]

Hey folks,
Just passing on some issues that automation picked up.


On 6 January 2023 06:05:32 GMT, Sia Jee Heng <jeeheng.sia at starfivetech.com> wrote:
>This series adds RISC-V Hibernation/suspend to disk support.
>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_hibernation_header_restore() and arch_hibernation_header_save()
>functions are implemented to prevent kernel crash when resume,
>the kernel built version is 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, 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
>
>
>At high-level, this series includes the following changes:
>1) Change suspend_save_csrs() and suspend_restore_csrs()
>   to public function as these functions are common to
>   suspend/hibernation. (patch 1)
>2) Enhance kernel_page_present() function to support huge page. (patch 2)
>3) Add arch/riscv low level functions to support
>   hibernation/suspend to disk. (patch 3)
>
>The above patches are based on kernel v6.2-rc2 and are tested on
>Starfive VF2 SBC board.
>
>Sia Jee Heng (3):
>  RISC-V: Change suspend_save_csrs and suspend_restore_csrs to public
>    function
>  RISC-V: mm: Enable huge page support to kernel_page_present() function

Unfortunately this breaks rv32_defconfig
https://patchwork.kernel.org/project/linux-riscv/patch/20230106060535.104321-3-jeeheng.sia@starfivetech.com/

>  RISC-V: Add arch functions to support hibernation/suspend-to-disk

This one then breaks rv64 allmodconfig too :/

https://patchwork.kernel.org/project/linux-riscv/patch/20230106060535.104321-4-jeeheng.sia@starfivetech.com/

Thanks,
Conor.

>
> arch/riscv/Kconfig                |   7 +
> arch/riscv/include/asm/suspend.h  |  23 ++
> arch/riscv/kernel/Makefile        |   2 +-
> arch/riscv/kernel/asm-offsets.c   |   5 +
> arch/riscv/kernel/hibernate-asm.S | 123 +++++++++++
> arch/riscv/kernel/hibernate.c     | 353 ++++++++++++++++++++++++++++++
> arch/riscv/kernel/suspend.c       |   4 +-
> arch/riscv/mm/pageattr.c          |   6 +
> 8 files changed, 520 insertions(+), 3 deletions(-)
> create mode 100644 arch/riscv/kernel/hibernate-asm.S
> create mode 100644 arch/riscv/kernel/hibernate.c
>
>
>base-commit: 1f5abbd77e2c1787e74b7c2caffac97def78ba52