xtensa: add hibernation support

Define ARCH_HIBERNATION_POSSIBLE in Kconfig and implement hibernation
callbacks.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/arch/xtensa/kernel/hibernate.c b/arch/xtensa/kernel/hibernate.c
new file mode 100644
index 000000000000..06984327d6e2
--- /dev/null
+++ b/arch/xtensa/kernel/hibernate.c
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/mm.h>
+#include <linux/suspend.h>
+#include <asm/coprocessor.h>
+
+int pfn_is_nosave(unsigned long pfn)
+{
+	unsigned long nosave_begin_pfn = PFN_DOWN(__pa(&__nosave_begin));
+	unsigned long nosave_end_pfn = PFN_UP(__pa(&__nosave_end));
+
+	return	(pfn >= nosave_begin_pfn) && (pfn < nosave_end_pfn);
+}
+
+void notrace save_processor_state(void)
+{
+	WARN_ON(num_online_cpus() != 1);
+#if XTENSA_HAVE_COPROCESSORS
+	local_coprocessors_flush_release_all();
+#endif
+}
+
+void notrace restore_processor_state(void)
+{
+}