arm64: hibernate: preserve kdump image around hibernation
Since arch_kexec_protect_crashkres() removes a mapping for crash dump
kernel image, the loaded data won't be preserved around hibernation.
In this patch, helper functions, crash_prepare_suspend()/
crash_post_resume(), are additionally called before/after hibernation so
that the relevant memory segments will be mapped again and preserved just
as the others are.
In addition, to minimize the size of hibernation image, crash_is_nosave()
is added to pfn_is_nosave() in order to recognize only the pages that hold
loaded crash dump kernel image as saveable. Hibernation excludes any pages
that are marked as Reserved and yet "nosave."
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 09d1920..89ba3cd 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -134,10 +134,35 @@ static void __init reserve_crashkernel(void)
crashk_res.start = crash_base;
crashk_res.end = crash_base + crash_size - 1;
}
+
+static void __init kexec_reserve_crashkres_pages(void)
+{
+#ifdef CONFIG_HIBERNATION
+ phys_addr_t addr;
+ struct page *page;
+
+ if (!crashk_res.end)
+ return;
+
+ /*
+ * To reduce the size of hibernation image, all the pages are
+ * marked as Reserved initially.
+ */
+ for (addr = crashk_res.start; addr < (crashk_res.end + 1);
+ addr += PAGE_SIZE) {
+ page = phys_to_page(addr);
+ SetPageReserved(page);
+ }
+#endif
+}
#else
static void __init reserve_crashkernel(void)
{
}
+
+static void __init kexec_reserve_crashkres_pages(void)
+{
+}
#endif /* CONFIG_KEXEC_CORE */
/*
@@ -517,6 +542,8 @@ void __init mem_init(void)
/* this will put all unused low memory onto the freelists */
free_all_bootmem();
+ kexec_reserve_crashkres_pages();
+
mem_init_print_info(NULL);
#define MLK(b, t) b, t, ((t) - (b)) >> 10