[PATCH v4 2/4] RISC-V: Factor out common code of __cpu_resume_enter()

From: Sia Jee Heng
Date: Mon Feb 20 2023 - 21:36:18 EST


The cpu_resume() function is very similar for the suspend to disk and
suspend to ram cases. Factor out the common code into restore_csr macro
and restore_reg macro.

Signed-off-by: Sia Jee Heng <jeeheng.sia@xxxxxxxxxxxxxxxx>
---
arch/riscv/include/asm/assembler.h | 62 ++++++++++++++++++++++++++++++
arch/riscv/kernel/suspend_entry.S | 34 ++--------------
2 files changed, 65 insertions(+), 31 deletions(-)
create mode 100644 arch/riscv/include/asm/assembler.h

diff --git a/arch/riscv/include/asm/assembler.h b/arch/riscv/include/asm/assembler.h
new file mode 100644
index 000000000000..727a97735493
--- /dev/null
+++ b/arch/riscv/include/asm/assembler.h
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2023 StarFive Technology Co., Ltd.
+ *
+ * Author: Jee Heng Sia <jeeheng.sia@xxxxxxxxxxxxxxxx>
+ */
+
+#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>
+
+/*
+ * restore_csr - restore hart's CSR value
+ */
+ .macro restore_csr
+ 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
+
+/*
+ * restore_reg - Restore registers (except A0 and T0-T6)
+ */
+ .macro restore_reg
+ 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
+
+#endif /* __ASM_ASSEMBLER_H */
diff --git a/arch/riscv/kernel/suspend_entry.S b/arch/riscv/kernel/suspend_entry.S
index aafcca58c19d..74a8fab8e0f6 100644
--- a/arch/riscv/kernel/suspend_entry.S
+++ b/arch/riscv/kernel/suspend_entry.S
@@ -7,6 +7,7 @@
#include <linux/linkage.h>
#include <asm/asm.h>
#include <asm/asm-offsets.h>
+#include <asm/assembler.h>
#include <asm/csr.h>
#include <asm/xip_fixup.h>

@@ -83,39 +84,10 @@ ENTRY(__cpu_resume_enter)
add a0, a1, zero

/* 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
+ restore_csr

/* Restore registers (except A0 and T0-T6) */
- 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)
+ restore_reg

/* Return zero value */
add a0, zero, zero
--
2.34.1