[PATCH v2 2/2] arm64: acpi: Honour firmware_signature field of FACS, if it exists

From: David Woodhouse
Date: Fri Apr 12 2024 - 04:06:56 EST


From: David Woodhouse <dwmw@xxxxxxxxxxxx>

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@xxxxxxxxxxxx>
Acked-by: Sudeep Holla <sudeep.holla@xxxxxxx>
---
arch/arm64/kernel/acpi.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
index dba8fcec7f33..e0e7b93c16cc 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 @@ void __init acpi_boot_table_init(void)
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);
--
2.44.0