From: David Woodhouse <dwmw@amazon.co.uk>
Date: Mon, 11 Mar 2024 13:04:07 +0000 (+0000)
Subject: arm64: acpi: Honour firmware_signature field of FACS, if it exists
X-Git-Tag: v6.10-rc1~182^2~6^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=fbaad243b5368f19c1e96dc9d914eefaebcb6ecc;p=thirdparty%2Fkernel%2Flinux.git

arm64: acpi: Honour firmware_signature field of FACS, if it exists

If the firmware_signature changes then OSPM should not attempt to resume
from hibernate, but should instead perform a clean reboot. Set the global
swsusp_hardware_signature to allow the generic code to include the value
in the swsusp header on disk, and perform the appropriate check on resume.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20240412073530.2222496-3-dwmw2@infradead.org
Signed-off-by: Will Deacon <will@kernel.org>
---

diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index dba8fcec7f33d..e0e7b93c16cc4 100644
--- a/arch/arm64/kernel/acpi.c
+++ b/arch/arm64/kernel/acpi.c
@@ -26,6 +26,7 @@
 #include <linux/libfdt.h>
 #include <linux/smp.h>
 #include <linux/serial_core.h>
+#include <linux/suspend.h>
 #include <linux/pgtable.h>
 
 #include <acpi/ghes.h>
@@ -227,6 +228,15 @@ done:
 		if (earlycon_acpi_spcr_enable)
 			early_init_dt_scan_chosen_stdout();
 	} else {
+#ifdef CONFIG_HIBERNATION
+		struct acpi_table_header *facs = NULL;
+		acpi_get_table(ACPI_SIG_FACS, 1, &facs);
+		if (facs) {
+			swsusp_hardware_signature =
+				((struct acpi_table_facs *)facs)->hardware_signature;
+			acpi_put_table(facs);
+		}
+#endif
 		acpi_parse_spcr(earlycon_acpi_spcr_enable, true);
 		if (IS_ENABLED(CONFIG_ACPI_BGRT))
 			acpi_table_parse(ACPI_SIG_BGRT, acpi_parse_bgrt);