[PATCH] efi/libstub: arm: Omit arch specific config table matching array on arm64

[PATCH] efi/libstub: arm: Omit arch specific config table matching array on arm64

[Ard Biesheuvel]

On arm64, the EFI stub is built into the kernel proper, and so the stub
can refer to its symbols directly. Therefore, the practice of using EFI
configuration tables to pass information between them is never needed,
so we can omit any code consuming such tables when building for arm64.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---

This will be applied before 'efi/libstub: arm: Print CPU boot mode and MMU 
state at boot' [v3] sent out today

 drivers/firmware/efi/arm-init.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c
index c697e70ca7e7..6f4baf70db16 100644
--- a/drivers/firmware/efi/arm-init.c
+++ b/drivers/firmware/efi/arm-init.c
@@ -62,7 +62,8 @@ static void __init init_screen_info(void)
 {
 	struct screen_info *si;
 
-	if (screen_info_table != EFI_INVALID_TABLE_ADDR) {
+	if (IS_ENABLED(CONFIG_ARM) &&
+	    screen_info_table != EFI_INVALID_TABLE_ADDR) {
 		si = early_memremap_ro(screen_info_table, sizeof(*si));
 		if (!si) {
 			pr_err("Could not map screen_info config table\n");
@@ -116,7 +117,8 @@ static int __init uefi_init(u64 efi_system_table)
 		goto out;
 	}
 	retval = efi_config_parse_tables(config_tables, systab->nr_tables,
-					 arch_tables);
+					 IS_ENABLED(CONFIG_ARM) ? arch_tables
+								: NULL);
 
 	early_memunmap(config_tables, table_size);
 out:
-- 
2.27.0

Re: [PATCH] efi/libstub: arm: Omit arch specific config table matching array on arm64

[Leif Lindholm]

On Tue, Jun 16, 2020 at 13:00:30 +0200, Ard Biesheuvel wrote:
> On arm64, the EFI stub is built into the kernel proper, and so the stub
> can refer to its symbols directly. Therefore, the practice of using EFI
> configuration tables to pass information between them is never needed,
> so we can omit any code consuming such tables when building for arm64.
> 
> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
>
> ---
> 
> This will be applied before 'efi/libstub: arm: Print CPU boot mode and MMU 
> state at boot' [v3] sent out today

With that, for *both* patches:
Reviewed-by: Leif Lindholm <leif@nuviainc.com>

>  drivers/firmware/efi/arm-init.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c
> index c697e70ca7e7..6f4baf70db16 100644
> --- a/drivers/firmware/efi/arm-init.c
> +++ b/drivers/firmware/efi/arm-init.c
> @@ -62,7 +62,8 @@ static void __init init_screen_info(void)
>  {
>  	struct screen_info *si;
>  
> -	if (screen_info_table != EFI_INVALID_TABLE_ADDR) {
> +	if (IS_ENABLED(CONFIG_ARM) &&
> +	    screen_info_table != EFI_INVALID_TABLE_ADDR) {
>  		si = early_memremap_ro(screen_info_table, sizeof(*si));
>  		if (!si) {
>  			pr_err("Could not map screen_info config table\n");
> @@ -116,7 +117,8 @@ static int __init uefi_init(u64 efi_system_table)
>  		goto out;
>  	}
>  	retval = efi_config_parse_tables(config_tables, systab->nr_tables,
> -					 arch_tables);
> +					 IS_ENABLED(CONFIG_ARM) ? arch_tables
> +								: NULL);
>  
>  	early_memunmap(config_tables, table_size);
>  out:
> -- 
> 2.27.0
>