efi/libstub: Add missing prototype for PE/COFF entry point

Fix a missing prototype warning by adding a forward declaration
for the PE/COFF entrypoint, and while at it, align the function
name between the x86 and ARM versions of the stub.

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

arch/arm/boot/compressed/efi-header.S

@@ -60,7 +60,7 @@ optional_header:
 		.long	__pecoff_code_size		@ SizeOfCode
 		.long	__pecoff_data_size		@ SizeOfInitializedData
 		.long	0				@ SizeOfUninitializedData
-		.long	efi_entry - start		@ AddressOfEntryPoint
+		.long	efi_pe_entry - start		@ AddressOfEntryPoint
 		.long	start_offset			@ BaseOfCode
 		.long	__pecoff_data_start - start	@ BaseOfData
 

arch/arm64/kernel/efi-entry.S

@@ -14,7 +14,7 @@
 
 SYM_CODE_START(efi_enter_kernel)
 	/*
-	 * efi_entry() will have copied the kernel image if necessary and we
+	 * efi_pe_entry() will have copied the kernel image if necessary and we
 	 * end up here with device tree address in x1 and the kernel entry
 	 * point stored in x0. Save those values in registers which are
 	 * callee preserved.

arch/arm64/kernel/efi-header.S

@@ -27,7 +27,7 @@ optional_header:
 	.long	__initdata_begin - efi_header_end	// SizeOfCode
 	.long	__pecoff_data_size			// SizeOfInitializedData
 	.long	0					// SizeOfUninitializedData
-	.long	__efistub_efi_entry - _head		// AddressOfEntryPoint
+	.long	__efistub_efi_pe_entry - _head		// AddressOfEntryPoint
 	.long	efi_header_end - _head			// BaseOfCode
 
 extra_header_fields:

drivers/firmware/efi/libstub/efi-stub.c

@@ -140,7 +140,8 @@ asmlinkage void __noreturn efi_enter_kernel(unsigned long entrypoint,
  * for both archictectures, with the arch-specific code provided in the
  * handle_kernel_image() function.
  */
-efi_status_t efi_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg)
+efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
+				   efi_system_table_t *sys_table_arg)
 {
 	efi_loaded_image_t *image;
 	efi_status_t status;

drivers/firmware/efi/libstub/efistub.h

@@ -40,6 +40,9 @@ extern bool efi_novamap;
 
 extern const efi_system_table_t *efi_system_table;
 
+efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
+				   efi_system_table_t *sys_table_arg);
+
 #ifndef ARCH_HAS_EFISTUB_WRAPPERS
 
 #define efi_is_native()		(true)