Messages in this thread | | | From | JeeHeng Sia <> | Subject | RE: [PATCH v7 4/4] RISC-V: Add arch functions to support hibernation/suspend-to-disk | Date | Tue, 28 Mar 2023 06:23:51 +0000 |
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> -----Original Message----- > From: Andrew Jones <ajones@ventanamicro.com> > Sent: Monday, March 27, 2023 9:23 PM > To: JeeHeng Sia <jeeheng.sia@starfivetech.com> > Cc: paul.walmsley@sifive.com; palmer@dabbelt.com; aou@eecs.berkeley.edu; linux-riscv@lists.infradead.org; linux- > kernel@vger.kernel.org; Leyfoon Tan <leyfoon.tan@starfivetech.com>; Mason Huo <mason.huo@starfivetech.com>; Conor Dooley > <conor.dooley@microchip.com> > Subject: Re: [PATCH v7 4/4] RISC-V: Add arch functions to support hibernation/suspend-to-disk > > On Mon, Mar 27, 2023 at 03:10:25PM +0200, Andrew Jones wrote: > > 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@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> > > > --- > > > 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@ventanamicro.com> > > Actually, I forgot to point out something. As hibernation depends on > suspend.c for save/restore_csrs, we need something like > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 73cca7f17f6f..f1d2289df660 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -54,7 +54,7 @@ config RISCV > select CLINT_TIMER if !MMU > select CLONE_BACKWARDS > select COMMON_CLK > - select CPU_PM if CPU_IDLE > + select CPU_PM if CPU_IDLE || HIBERNATION Sure. Will add it > select EDAC_SUPPORT > select GENERIC_ARCH_TOPOLOGY > select GENERIC_ATOMIC64 if !64BIT > > > Thanks, > drew
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