Commit c0317210 authored by Sia Jee Heng's avatar Sia Jee Heng Committed by Palmer Dabbelt

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: default avatarSia Jee Heng <jeeheng.sia@starfivetech.com>
Reviewed-by: default avatarLey Foon Tan <leyfoon.tan@starfivetech.com>
Reviewed-by: default avatarMason Huo <mason.huo@starfivetech.com>
Reviewed-by: default avatarConor Dooley <conor.dooley@microchip.com>
Reviewed-by: default avatarAndrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20230330064321.1008373-5-jeeheng.sia@starfivetech.comSigned-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent a15c90b6
...@@ -54,7 +54,7 @@ config RISCV ...@@ -54,7 +54,7 @@ config RISCV
select CLINT_TIMER if !MMU select CLINT_TIMER if !MMU
select CLONE_BACKWARDS select CLONE_BACKWARDS
select COMMON_CLK select COMMON_CLK
select CPU_PM if CPU_IDLE select CPU_PM if CPU_IDLE || HIBERNATION
select EDAC_SUPPORT select EDAC_SUPPORT
select GENERIC_ARCH_TOPOLOGY select GENERIC_ARCH_TOPOLOGY
select GENERIC_ATOMIC64 if !64BIT select GENERIC_ATOMIC64 if !64BIT
...@@ -707,6 +707,12 @@ menu "Power management options" ...@@ -707,6 +707,12 @@ menu "Power management options"
source "kernel/power/Kconfig" source "kernel/power/Kconfig"
config ARCH_HIBERNATION_POSSIBLE
def_bool y
config ARCH_HIBERNATION_HEADER
def_bool HIBERNATION
endmenu # "Power management options" endmenu # "Power management options"
menu "CPU Power Management" menu "CPU Power Management"
......
...@@ -59,4 +59,24 @@ ...@@ -59,4 +59,24 @@
REG_L s11, (SUSPEND_CONTEXT_REGS + PT_S11)(a0) REG_L s11, (SUSPEND_CONTEXT_REGS + PT_S11)(a0)
.endm .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 */ #endif /* __ASM_ASSEMBLER_H */
...@@ -21,6 +21,11 @@ struct suspend_context { ...@@ -21,6 +21,11 @@ struct suspend_context {
#endif #endif
}; };
/*
* Used by hibernation core and cleared during resume sequence
*/
extern int in_suspend;
/* Low-level CPU suspend entry function */ /* Low-level CPU suspend entry function */
int __cpu_suspend_enter(struct suspend_context *context); int __cpu_suspend_enter(struct suspend_context *context);
...@@ -36,4 +41,18 @@ int __cpu_resume_enter(unsigned long hartid, unsigned long context); ...@@ -36,4 +41,18 @@ int __cpu_resume_enter(unsigned long hartid, unsigned long context);
/* Used to save and restore the CSRs */ /* Used to save and restore the CSRs */
void suspend_save_csrs(struct suspend_context *context); void suspend_save_csrs(struct suspend_context *context);
void suspend_restore_csrs(struct suspend_context *context); void suspend_restore_csrs(struct suspend_context *context);
/* Low-level API to support hibernation */
int swsusp_arch_suspend(void);
int swsusp_arch_resume(void);
int arch_hibernation_header_save(void *addr, unsigned int max_size);
int arch_hibernation_header_restore(void *addr);
int __hibernate_cpu_resume(void);
/* Used to resume on the CPU we hibernated on */
int hibernate_resume_nonboot_cpu_disable(void);
asmlinkage void hibernate_restore_image(unsigned long resume_satp, unsigned long satp_temp,
unsigned long cpu_resume);
asmlinkage int hibernate_core_restore_code(void);
#endif #endif
...@@ -64,6 +64,7 @@ obj-$(CONFIG_MODULES) += module.o ...@@ -64,6 +64,7 @@ obj-$(CONFIG_MODULES) += module.o
obj-$(CONFIG_MODULE_SECTIONS) += module-sections.o obj-$(CONFIG_MODULE_SECTIONS) += module-sections.o
obj-$(CONFIG_CPU_PM) += suspend_entry.o suspend.o obj-$(CONFIG_CPU_PM) += suspend_entry.o suspend.o
obj-$(CONFIG_HIBERNATION) += hibernate.o hibernate-asm.o
obj-$(CONFIG_FUNCTION_TRACER) += mcount.o ftrace.o obj-$(CONFIG_FUNCTION_TRACER) += mcount.o ftrace.o
obj-$(CONFIG_DYNAMIC_FTRACE) += mcount-dyn.o obj-$(CONFIG_DYNAMIC_FTRACE) += mcount-dyn.o
......
...@@ -9,6 +9,7 @@ ...@@ -9,6 +9,7 @@
#include <linux/kbuild.h> #include <linux/kbuild.h>
#include <linux/mm.h> #include <linux/mm.h>
#include <linux/sched.h> #include <linux/sched.h>
#include <linux/suspend.h>
#include <asm/kvm_host.h> #include <asm/kvm_host.h>
#include <asm/thread_info.h> #include <asm/thread_info.h>
#include <asm/ptrace.h> #include <asm/ptrace.h>
...@@ -116,6 +117,10 @@ void asm_offsets(void) ...@@ -116,6 +117,10 @@ void asm_offsets(void)
OFFSET(SUSPEND_CONTEXT_REGS, suspend_context, regs); OFFSET(SUSPEND_CONTEXT_REGS, suspend_context, regs);
OFFSET(HIBERN_PBE_ADDR, pbe, address);
OFFSET(HIBERN_PBE_ORIG, pbe, orig_address);
OFFSET(HIBERN_PBE_NEXT, pbe, next);
OFFSET(KVM_ARCH_GUEST_ZERO, kvm_vcpu_arch, guest_context.zero); OFFSET(KVM_ARCH_GUEST_ZERO, kvm_vcpu_arch, guest_context.zero);
OFFSET(KVM_ARCH_GUEST_RA, kvm_vcpu_arch, guest_context.ra); OFFSET(KVM_ARCH_GUEST_RA, kvm_vcpu_arch, guest_context.ra);
OFFSET(KVM_ARCH_GUEST_SP, kvm_vcpu_arch, guest_context.sp); OFFSET(KVM_ARCH_GUEST_SP, kvm_vcpu_arch, guest_context.sp);
......
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Hibernation low level support for RISCV.
*
* Copyright (C) 2023 StarFive Technology Co., Ltd.
*
* Author: Jee Heng Sia <jeeheng.sia@starfivetech.com>
*/
#include <asm/asm.h>
#include <asm/asm-offsets.h>
#include <asm/assembler.h>
#include <asm/csr.h>
#include <linux/linkage.h>
/*
* int __hibernate_cpu_resume(void)
* Switch back to the hibernated image's page table prior to restoring the CPU
* context.
*
* Always returns 0
*/
ENTRY(__hibernate_cpu_resume)
/* switch to hibernated image's page table. */
csrw CSR_SATP, s0
sfence.vma
REG_L a0, hibernate_cpu_context
suspend_restore_csrs
suspend_restore_regs
/* Return zero value. */
mv a0, zero
ret
END(__hibernate_cpu_resume)
/*
* Prepare to restore the image.
* a0: satp of saved page tables.
* a1: satp of temporary page tables.
* a2: cpu_resume.
*/
ENTRY(hibernate_restore_image)
mv s0, a0
mv s1, a1
mv s2, a2
REG_L s4, restore_pblist
REG_L a1, relocated_restore_code
jalr a1
END(hibernate_restore_image)
/*
* The below code will be executed from a 'safe' page.
* It first switches to the temporary page table, then starts to copy the pages
* back to the original memory location. Finally, it jumps to __hibernate_cpu_resume()
* to restore the CPU context.
*/
ENTRY(hibernate_core_restore_code)
/* switch to temp page table. */
csrw satp, s1
sfence.vma
.Lcopy:
/* The below code will restore the hibernated image. */
REG_L a1, HIBERN_PBE_ADDR(s4)
REG_L a0, HIBERN_PBE_ORIG(s4)
copy_page a0, a1
REG_L s4, HIBERN_PBE_NEXT(s4)
bnez s4, .Lcopy
jalr s2
END(hibernate_core_restore_code)
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