1 files changed, 105 insertions, 0 deletions
diff --git a/arch/arm/kernel/hibernate.c b/arch/arm/kernel/hibernate.c
new file mode 100644
index 000000000..2373020af
--- /dev/null
+++ b/arch/arm/kernel/hibernate.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Hibernation support specific for ARM
+ *
+ * Derived from work on ARM hibernation support by:
+ *
+ * Ubuntu project, hibernation support for mach-dove
+ * Copyright (C) 2010 Nokia Corporation (Hiroshi Doyu)
+ * Copyright (C) 2010 Texas Instruments, Inc. (Teerth Reddy et al.)
+ *  https://lkml.org/lkml/2010/6/18/4
+ *  https://lists.linux-foundation.org/pipermail/linux-pm/2010-June/027422.html
+ *  https://patchwork.kernel.org/patch/96442/
+ *
+ * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
+ */
+
+#include <linux/mm.h>
+#include <linux/suspend.h>
+#include <asm/system_misc.h>
+#include <asm/idmap.h>
+#include <asm/suspend.h>
+#include <asm/memory.h>
+#include <asm/sections.h>
+#include "reboot.h"
+
+int pfn_is_nosave(unsigned long pfn)
+{
+	unsigned long nosave_begin_pfn = virt_to_pfn(&__nosave_begin);
+	unsigned long nosave_end_pfn = virt_to_pfn(&__nosave_end - 1);
+
+	return (pfn >= nosave_begin_pfn) && (pfn <= nosave_end_pfn);
+}
+
+void notrace save_processor_state(void)
+{
+	WARN_ON(num_online_cpus() != 1);
+	local_fiq_disable();
+}
+
+void notrace restore_processor_state(void)
+{
+	local_fiq_enable();
+}
+
+/*
+ * Snapshot kernel memory and reset the system.
+ *
+ * swsusp_save() is executed in the suspend finisher so that the CPU
+ * context pointer and memory are part of the saved image, which is
+ * required by the resume kernel image to restart execution from
+ * swsusp_arch_suspend().
+ *
+ * soft_restart is not technically needed, but is used to get success
+ * returned from cpu_suspend.
+ *
+ * When soft reboot completes, the hibernation snapshot is written out.
+ */
+static int notrace arch_save_image(unsigned long unused)
+{
+	int ret;
+
+	ret = swsusp_save();
+	if (ret == 0)
+		_soft_restart(virt_to_idmap(cpu_resume), false);
+	return ret;
+}
+
+/*
+ * Save the current CPU state before suspend / poweroff.
+ */
+int notrace swsusp_arch_suspend(void)
+{
+	return cpu_suspend(0, arch_save_image);
+}
+
+/*
+ * Restore page contents for physical pages that were in use during loading
+ * hibernation image.  Switch to idmap_pgd so the physical page tables
+ * are overwritten with the same contents.
+ */
+static void notrace arch_restore_image(void *unused)
+{
+	struct pbe *pbe;
+
+	cpu_switch_mm(idmap_pgd, &init_mm);
+	for (pbe = restore_pblist; pbe; pbe = pbe->next)
+		copy_page(pbe->orig_address, pbe->address);
+
+	_soft_restart(virt_to_idmap(cpu_resume), false);
+}
+
+static u64 resume_stack[PAGE_SIZE/2/sizeof(u64)] __nosavedata;
+
+/*
+ * Resume from the hibernation image.
+ * Due to the kernel heap / data restore, stack contents change underneath
+ * and that would make function calls impossible; switch to a temporary
+ * stack within the nosave region to avoid that problem.
+ */
+int swsusp_arch_resume(void)
+{
+	call_with_stack(arch_restore_image, 0,
+		resume_stack + ARRAY_SIZE(resume_stack));
+	return 0;
+}