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author | Palmer Dabbelt <palmer@rivosinc.com> | 2023-04-29 20:25:15 +0200 |
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committer | Palmer Dabbelt <palmer@rivosinc.com> | 2023-04-29 20:27:33 +0200 |
commit | 38dab744f77f6d61f6d08334f83948ce9faadd3a (patch) | |
tree | bc4306801de01cfe70049c5b6daf1081cf7e16de /arch/riscv/include/asm | |
parent | riscv: Adjust dependencies of HAVE_DYNAMIC_FTRACE selection (diff) | |
parent | RISC-V: Add arch functions to support hibernation/suspend-to-disk (diff) | |
download | linux-38dab744f77f6d61f6d08334f83948ce9faadd3a.tar.xz linux-38dab744f77f6d61f6d08334f83948ce9faadd3a.zip |
Merge patch series "RISC-V Hibernation Support"
Sia Jee Heng <jeeheng.sia@starfivetech.com> says:
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 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
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) Refactor the common code in the __cpu_resume_enter() function and
__hibernate_cpu_resume() function. The common code are used by
hibernation and suspend. (patch 2)
3) Enhance kernel_page_present() function to support huge page. (patch 3)
4) Add arch/riscv low level functions to support
hibernation/suspend to disk. (patch 4)
* b4-shazam-merge:
RISC-V: Add arch functions to support hibernation/suspend-to-disk
RISC-V: mm: Enable huge page support to kernel_page_present() function
RISC-V: Factor out common code of __cpu_resume_enter()
RISC-V: Change suspend_save_csrs and suspend_restore_csrs to public function
Link: https://lore.kernel.org/r/20230330064321.1008373-1-jeeheng.sia@starfivetech.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/include/asm')
-rw-r--r-- | arch/riscv/include/asm/assembler.h | 82 | ||||
-rw-r--r-- | arch/riscv/include/asm/suspend.h | 22 |
2 files changed, 104 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/assembler.h b/arch/riscv/include/asm/assembler.h new file mode 100644 index 000000000000..44b1457d3e95 --- /dev/null +++ b/arch/riscv/include/asm/assembler.h @@ -0,0 +1,82 @@ +/* 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 */ diff --git a/arch/riscv/include/asm/suspend.h b/arch/riscv/include/asm/suspend.h index 8be391c2aecb..02f87867389a 100644 --- a/arch/riscv/include/asm/suspend.h +++ b/arch/riscv/include/asm/suspend.h @@ -21,6 +21,11 @@ struct suspend_context { #endif }; +/* + * Used by hibernation core and cleared during resume sequence + */ +extern int in_suspend; + /* Low-level CPU suspend entry function */ int __cpu_suspend_enter(struct suspend_context *context); @@ -33,4 +38,21 @@ int cpu_suspend(unsigned long arg, /* Low-level CPU resume entry function */ int __cpu_resume_enter(unsigned long hartid, unsigned long context); +/* Used to save and restore the CSRs */ +void suspend_save_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 |