Re: [PATCH v2 02/10] xen/x86: move reusable EFI stub functions from x86 to common

[Stefano Stabellini <sstabellini@kernel.org>]

On Mon, 18 Apr 2022, Wei Chen wrote:
> Most of the functions in x86 EFI stub.c can be reused for other
> architectures. So we move them to common and keep the x86 specific
> function in stub-x86.c.
> 
> Signed-off-by: Wei Chen <wei.chen@arm.com>

Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>


> ---
> v1 -> v2:
> 1. Drop the copy of stub.c from Arm EFI.
> 2. Share common codes of x86 EFI stub for other architectures.
> ---
>  xen/arch/x86/efi/Makefile               |  4 +--
>  xen/arch/x86/efi/{stub.c => stub-x86.c} | 37 ------------------------
>  xen/common/efi/stub.c                   | 38 +++++++++++++++++++++++++
>  3 files changed, 40 insertions(+), 39 deletions(-)
>  rename xen/arch/x86/efi/{stub.c => stub-x86.c} (71%)
>  create mode 100644 xen/common/efi/stub.c
> 
> diff --git a/xen/arch/x86/efi/Makefile b/xen/arch/x86/efi/Makefile
> index 034ec87895..5ca3a0b4a4 100644
> --- a/xen/arch/x86/efi/Makefile
> +++ b/xen/arch/x86/efi/Makefile
> @@ -11,8 +11,8 @@ $(obj)/boot.init.o: $(obj)/buildid.o
>  $(call cc-option-add,cflags-stack-boundary,CC,-mpreferred-stack-boundary=4)
>  $(addprefix $(obj)/,$(EFIOBJ-y)): CFLAGS_stack_boundary := $(cflags-stack-boundary)
>  
> -obj-y := stub.o
> +obj-y := stub.o stub-x86.o
>  obj-$(XEN_BUILD_EFI) := $(filter-out %.init.o,$(EFIOBJ-y))
>  obj-bin-$(XEN_BUILD_EFI) := $(filter %.init.o,$(EFIOBJ-y))
>  extra-$(XEN_BUILD_EFI) += buildid.o relocs-dummy.o
> -nocov-$(XEN_BUILD_EFI) += stub.o
> +nocov-$(XEN_BUILD_EFI) += stub.o stub-x86.o
> diff --git a/xen/arch/x86/efi/stub.c b/xen/arch/x86/efi/stub-x86.c
> similarity index 71%
> rename from xen/arch/x86/efi/stub.c
> rename to xen/arch/x86/efi/stub-x86.c
> index 9984932626..2cd5c8d4dc 100644
> --- a/xen/arch/x86/efi/stub.c
> +++ b/xen/arch/x86/efi/stub-x86.c
> @@ -1,7 +1,5 @@
>  #include <xen/efi.h>
> -#include <xen/errno.h>
>  #include <xen/init.h>
> -#include <xen/lib.h>
>  #include <asm/asm_defns.h>
>  #include <asm/efibind.h>
>  #include <asm/page.h>
> @@ -45,11 +43,6 @@ void __init noreturn efi_multiboot2(EFI_HANDLE ImageHandle,
>      unreachable();
>  }
>  
> -bool efi_enabled(unsigned int feature)
> -{
> -    return false;
> -}
> -
>  void __init efi_init_memory(void) { }
>  
>  bool efi_boot_mem_unused(unsigned long *start, unsigned long *end)
> @@ -61,33 +54,3 @@ bool efi_boot_mem_unused(unsigned long *start, unsigned long *end)
>  }
>  
>  void efi_update_l4_pgtable(unsigned int l4idx, l4_pgentry_t l4e) { }
> -
> -bool efi_rs_using_pgtables(void)
> -{
> -    return false;
> -}
> -
> -unsigned long efi_get_time(void)
> -{
> -    BUG();
> -    return 0;
> -}
> -
> -void efi_halt_system(void) { }
> -void efi_reset_system(bool warm) { }
> -
> -int efi_get_info(uint32_t idx, union xenpf_efi_info *info)
> -{
> -    return -ENOSYS;
> -}
> -
> -int efi_compat_get_info(uint32_t idx, union compat_pf_efi_info *)
> -    __attribute__((__alias__("efi_get_info")));
> -
> -int efi_runtime_call(struct xenpf_efi_runtime_call *op)
> -{
> -    return -ENOSYS;
> -}
> -
> -int efi_compat_runtime_call(struct compat_pf_efi_runtime_call *)
> -    __attribute__((__alias__("efi_runtime_call")));
> diff --git a/xen/common/efi/stub.c b/xen/common/efi/stub.c
> new file mode 100644
> index 0000000000..6e4f4de9af
> --- /dev/null
> +++ b/xen/common/efi/stub.c
> @@ -0,0 +1,38 @@
> +#include <xen/efi.h>
> +#include <xen/errno.h>
> +#include <xen/lib.h>
> +
> +bool efi_enabled(unsigned int feature)
> +{
> +    return false;
> +}
> +
> +bool efi_rs_using_pgtables(void)
> +{
> +    return false;
> +}
> +
> +unsigned long efi_get_time(void)
> +{
> +    BUG();
> +    return 0;
> +}
> +
> +void efi_halt_system(void) { }
> +void efi_reset_system(bool warm) { }
> +
> +int efi_get_info(uint32_t idx, union xenpf_efi_info *info)
> +{
> +    return -ENOSYS;
> +}
> +
> +int efi_compat_get_info(uint32_t idx, union compat_pf_efi_info *)
> +    __attribute__((__alias__("efi_get_info")));
> +
> +int efi_runtime_call(struct xenpf_efi_runtime_call *op)
> +{
> +    return -ENOSYS;
> +}
> +
> +int efi_compat_runtime_call(struct compat_pf_efi_runtime_call *)
> +    __attribute__((__alias__("efi_runtime_call")));
> -- 
> 2.25.1
> 
>