The following commit has been merged into the efi/urgent branch of tip:

Commit-ID: 435d1a471598752446a72ad1201b3c980526d869 Gitweb: https://git.kernel.org/tip/435d1a471598752446a72ad1201b3c980526d869 Author: Peter Jones pjones@redhat.com AuthorDate: Mon, 15 Jun 2020 16:24:08 -04:00 Committer: Ard Biesheuvel ardb@kernel.org CommitterDate: Tue, 16 Jun 2020 11:01:07 +02:00

efi: Make it possible to disable efivar_ssdt entirely

In most cases, such as CONFIG_ACPI_CUSTOM_DSDT and CONFIG_ACPI_TABLE_UPGRADE, boot-time modifications to firmware tables are tied to specific Kconfig options. Currently this is not the case for modifying the ACPI SSDT via the efivar_ssdt kernel command line option and associated EFI variable.

This patch adds CONFIG_EFI_CUSTOM_SSDT_OVERLAYS, which defaults disabled, in order to allow enabling or disabling that feature during the build.

Cc: stable@vger.kernel.org Signed-off-by: Peter Jones pjones@redhat.com Link: https://lore.kernel.org/r/20200615202408.2242614-1-pjones@redhat.com Signed-off-by: Ard Biesheuvel ardb@kernel.org --- drivers/firmware/efi/Kconfig | 11 +++++++++++ drivers/firmware/efi/efi.c | 2 +- 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index e6fc022..3939699 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -278,3 +278,14 @@ config EFI_EARLYCON depends on SERIAL_EARLYCON && !ARM && !IA64 select FONT_SUPPORT select ARCH_USE_MEMREMAP_PROT + +config EFI_CUSTOM_SSDT_OVERLAYS + bool "Load custom ACPI SSDT overlay from an EFI variable" + depends on EFI_VARS && ACPI + default ACPI_TABLE_UPGRADE + help + Allow loading of an ACPI SSDT overlay from an EFI variable specified + by a kernel command line option. + + See Documentation/admin-guide/acpi/ssdt-overlays.rst for more + information. diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index edc5d36..5114cae 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -189,7 +189,7 @@ static void generic_ops_unregister(void) efivars_unregister(&generic_efivars); }

-#if IS_ENABLED(CONFIG_ACPI) +#ifdef CONFIG_EFI_CUSTOM_SSDT_OVERLAYS #define EFIVAR_SSDT_NAME_MAX 16 static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata; static int __init efivar_ssdt_setup(char *str)