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authorPalmer Dabbelt <palmer@rivosinc.com>2023-04-29 20:25:15 +0200
committerPalmer Dabbelt <palmer@rivosinc.com>2023-04-29 20:27:33 +0200
commit38dab744f77f6d61f6d08334f83948ce9faadd3a (patch)
treebc4306801de01cfe70049c5b6daf1081cf7e16de /arch/riscv/include/asm
parentriscv: Adjust dependencies of HAVE_DYNAMIC_FTRACE selection (diff)
parentRISC-V: Add arch functions to support hibernation/suspend-to-disk (diff)
downloadlinux-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.h82
-rw-r--r--arch/riscv/include/asm/suspend.h22
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