summaryrefslogtreecommitdiff
path: root/arch/riscv/kernel/suspend_entry.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/riscv/kernel/suspend_entry.S')
-rw-r--r--arch/riscv/kernel/suspend_entry.S95
1 files changed, 95 insertions, 0 deletions
diff --git a/arch/riscv/kernel/suspend_entry.S b/arch/riscv/kernel/suspend_entry.S
new file mode 100644
index 000000000000..2d54f309c140
--- /dev/null
+++ b/arch/riscv/kernel/suspend_entry.S
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (c) 2022 Ventana Micro Systems Inc.
+ */
+
+#include <linux/linkage.h>
+#include <linux/cfi_types.h>
+#include <asm/asm.h>
+#include <asm/asm-offsets.h>
+#include <asm/assembler.h>
+#include <asm/csr.h>
+#include <asm/xip_fixup.h>
+
+ .text
+ .altmacro
+ .option norelax
+
+SYM_FUNC_START(__cpu_suspend_enter)
+ /* Save registers (except A0 and T0-T6) */
+ REG_S ra, (SUSPEND_CONTEXT_REGS + PT_RA)(a0)
+ REG_S sp, (SUSPEND_CONTEXT_REGS + PT_SP)(a0)
+ REG_S gp, (SUSPEND_CONTEXT_REGS + PT_GP)(a0)
+ REG_S tp, (SUSPEND_CONTEXT_REGS + PT_TP)(a0)
+ REG_S s0, (SUSPEND_CONTEXT_REGS + PT_S0)(a0)
+ REG_S s1, (SUSPEND_CONTEXT_REGS + PT_S1)(a0)
+ REG_S a1, (SUSPEND_CONTEXT_REGS + PT_A1)(a0)
+ REG_S a2, (SUSPEND_CONTEXT_REGS + PT_A2)(a0)
+ REG_S a3, (SUSPEND_CONTEXT_REGS + PT_A3)(a0)
+ REG_S a4, (SUSPEND_CONTEXT_REGS + PT_A4)(a0)
+ REG_S a5, (SUSPEND_CONTEXT_REGS + PT_A5)(a0)
+ REG_S a6, (SUSPEND_CONTEXT_REGS + PT_A6)(a0)
+ REG_S a7, (SUSPEND_CONTEXT_REGS + PT_A7)(a0)
+ REG_S s2, (SUSPEND_CONTEXT_REGS + PT_S2)(a0)
+ REG_S s3, (SUSPEND_CONTEXT_REGS + PT_S3)(a0)
+ REG_S s4, (SUSPEND_CONTEXT_REGS + PT_S4)(a0)
+ REG_S s5, (SUSPEND_CONTEXT_REGS + PT_S5)(a0)
+ REG_S s6, (SUSPEND_CONTEXT_REGS + PT_S6)(a0)
+ REG_S s7, (SUSPEND_CONTEXT_REGS + PT_S7)(a0)
+ REG_S s8, (SUSPEND_CONTEXT_REGS + PT_S8)(a0)
+ REG_S s9, (SUSPEND_CONTEXT_REGS + PT_S9)(a0)
+ REG_S s10, (SUSPEND_CONTEXT_REGS + PT_S10)(a0)
+ REG_S s11, (SUSPEND_CONTEXT_REGS + PT_S11)(a0)
+
+ /* Save CSRs */
+ csrr t0, CSR_EPC
+ REG_S t0, (SUSPEND_CONTEXT_REGS + PT_EPC)(a0)
+ csrr t0, CSR_STATUS
+ REG_S t0, (SUSPEND_CONTEXT_REGS + PT_STATUS)(a0)
+ csrr t0, CSR_TVAL
+ REG_S t0, (SUSPEND_CONTEXT_REGS + PT_BADADDR)(a0)
+ csrr t0, CSR_CAUSE
+ REG_S t0, (SUSPEND_CONTEXT_REGS + PT_CAUSE)(a0)
+
+ /* Return non-zero value */
+ li a0, 1
+
+ /* Return to C code */
+ ret
+SYM_FUNC_END(__cpu_suspend_enter)
+
+SYM_TYPED_FUNC_START(__cpu_resume_enter)
+ /* Load the global pointer */
+ load_global_pointer
+
+#ifdef CONFIG_MMU
+ /* Save A0 and A1 */
+ add t0, a0, zero
+ add t1, a1, zero
+
+ /* Enable MMU */
+ la a0, swapper_pg_dir
+ XIP_FIXUP_OFFSET a0
+ call relocate_enable_mmu
+
+ /* Restore A0 and A1 */
+ add a0, t0, zero
+ add a1, t1, zero
+#endif
+
+ /* Make A0 point to suspend context */
+ add a0, a1, zero
+
+ /* Restore CSRs */
+ suspend_restore_csrs
+
+ /* Restore registers (except A0 and T0-T6) */
+ suspend_restore_regs
+
+ /* Return zero value */
+ add a0, zero, zero
+
+ /* Return to C code */
+ ret
+SYM_FUNC_END(__cpu_resume_enter)