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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /arch/riscv/kernel/hibernate-asm.S
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/riscv/kernel/hibernate-asm.S')
-rw-r--r--arch/riscv/kernel/hibernate-asm.S76
1 files changed, 76 insertions, 0 deletions
diff --git a/arch/riscv/kernel/hibernate-asm.S b/arch/riscv/kernel/hibernate-asm.S
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+/* 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_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
+
+ jr 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
+
+ jr s2
+END(hibernate_core_restore_code)