On Wed, Dec 18, 2019 at 07:01:31PM +0200, Ard Biesheuvel wrote:
> The various pointers we stash in the efi_config struct which we
> retrieve using __efi_early() are simply copies of the ones in
> the EFI system table, which we have started accessing directly
> in the previous patch. So drop all the __efi_early() related
> plumbing, except for the access to a boolean which tells us
> whether the firmware is 64-bit or not.
>
> Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
> ---
> arch/x86/boot/compressed/eboot.c | 36 ++++++++------------
> arch/x86/boot/compressed/head_32.S | 2 +-
> arch/x86/boot/compressed/head_64.S | 4 +--
> arch/x86/include/asm/efi.h | 23 +++++--------
> 4 files changed, 26 insertions(+), 39 deletions(-)
>
> diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
> index 2bcab1ef5a56..53e67334c4c3 100644
> --- a/arch/x86/boot/compressed/eboot.c
> +++ b/arch/x86/boot/compressed/eboot.c
> @@ -20,11 +20,17 @@
>
> static efi_system_table_t *sys_table;
>
> -static struct efi_config *efi_early;
> +struct efi_config {
> + u64 image_handle;
> + u64 table;
> + bool is64;
> +} __packed;
>
> -__pure const struct efi_config *__efi_early(void)
> +static bool is64;
> +
> +__pure bool __efi_early_is64(void)
> {
> - return efi_early;
> + return is64;
> }
>
> __pure efi_system_table_t *efi_system_table(void)
This predates your series, but looking at the generated code I noticed
that pure isn't enough to let gcc optimize out repeated calls to is64
and system_table. Declaring them as __attribute_const__ would allow
optimization. They don't quite meet gcc's requirements for that as they
access global non-const variables, but it seems like it ought to be
safe, especially if we stop using the functions within eboot.c itself?
