efi/libstub: Unify initrd loading across architectures

Factor out the initrd loading into a common function that can be called
both from the generic efi-stub.c and the x86-specific x86-stub.c.
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200430182843.2510180-10-nivedita@alum.mit.eduSigned-off-by: Ard Biesheuvel <ardb@kernel.org>

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

@@ -331,6 +331,7 @@ static const struct {
  *		%EFI_OUT_OF_RESOURCES if memory allocation failed
  *		%EFI_LOAD_ERROR in all other cases
  */
+static
 efi_status_t efi_load_initrd_dev_path(unsigned long *load_addr,
 				      unsigned long *load_size,
 				      unsigned long max)
@@ -343,9 +344,6 @@ efi_status_t efi_load_initrd_dev_path(unsigned long *load_addr,
 	efi_handle_t handle;
 	efi_status_t status;
 
-	if (!load_addr || !load_size)
-		return EFI_INVALID_PARAMETER;
-
 	dp = (efi_device_path_protocol_t *)&initrd_dev_path;
 	status = efi_bs_call(locate_device_path, &lf2_proto_guid, &dp, &handle);
 	if (status != EFI_SUCCESS)
@@ -375,3 +373,45 @@ efi_status_t efi_load_initrd_dev_path(unsigned long *load_addr,
 	*load_size = initrd_size;
 	return EFI_SUCCESS;
 }
+
+static
+efi_status_t efi_load_initrd_cmdline(efi_loaded_image_t *image,
+				     unsigned long *load_addr,
+				     unsigned long *load_size,
+				     unsigned long soft_limit,
+				     unsigned long hard_limit)
+{
+	if (!IS_ENABLED(CONFIG_EFI_GENERIC_STUB_INITRD_CMDLINE_LOADER) ||
+	    (IS_ENABLED(CONFIG_X86) && (!efi_is_native() || image == NULL))) {
+		*load_addr = *load_size = 0;
+		return EFI_SUCCESS;
+	}
+
+	return handle_cmdline_files(image, L"initrd=", sizeof(L"initrd=") - 2,
+				    soft_limit, hard_limit,
+				    load_addr, load_size);
+}
+
+efi_status_t efi_load_initrd(efi_loaded_image_t *image,
+			     unsigned long *load_addr,
+			     unsigned long *load_size,
+			     unsigned long soft_limit,
+			     unsigned long hard_limit)
+{
+	efi_status_t status;
+
+	if (!load_addr || !load_size)
+		return EFI_INVALID_PARAMETER;
+
+	status = efi_load_initrd_dev_path(load_addr, load_size, hard_limit);
+	if (status == EFI_SUCCESS) {
+		efi_info("Loaded initrd from LINUX_EFI_INITRD_MEDIA_GUID device path\n");
+	} else if (status == EFI_NOT_FOUND) {
+		status = efi_load_initrd_cmdline(image, load_addr, load_size,
+						 soft_limit, hard_limit);
+		if (status == EFI_SUCCESS && *load_size > 0)
+			efi_info("Loaded initrd from command line option\n");
+	}
+
+	return status;
+}

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

@@ -265,16 +265,8 @@ efi_status_t efi_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg)
 
 	if (!efi_noinitrd) {
 		max_addr = efi_get_max_initrd_addr(dram_base, image_addr);
-		status = efi_load_initrd_dev_path(&initrd_addr, &initrd_size,
-						  max_addr);
-		if (status == EFI_SUCCESS) {
-			efi_info("Loaded initrd from LINUX_EFI_INITRD_MEDIA_GUID device path\n");
-		} else if (status == EFI_NOT_FOUND) {
-			status = efi_load_initrd(image, &initrd_addr, &initrd_size,
-						 ULONG_MAX, max_addr);
-			if (status == EFI_SUCCESS && initrd_size > 0)
-				efi_info("Loaded initrd from command line option\n");
-		}
+		status = efi_load_initrd(image, &initrd_addr, &initrd_size,
+					 ULONG_MAX, max_addr);
 		if (status != EFI_SUCCESS)
 			efi_err("Failed to load initrd!\n");
 	}

drivers/firmware/efi/libstub/efistub.h

@@ -677,21 +677,10 @@ static inline efi_status_t efi_load_dtb(efi_loaded_image_t *image,
 				    ULONG_MAX, ULONG_MAX, load_addr, load_size);
 }
 
-static inline efi_status_t efi_load_initrd(efi_loaded_image_t *image,
-					   unsigned long *load_addr,
-					   unsigned long *load_size,
-					   unsigned long soft_limit,
-					   unsigned long hard_limit)
-{
-	if (!IS_ENABLED(CONFIG_EFI_GENERIC_STUB_INITRD_CMDLINE_LOADER))
-		return EFI_SUCCESS;
-
-	return handle_cmdline_files(image, L"initrd=", sizeof(L"initrd=") - 2,
-				    soft_limit, hard_limit, load_addr, load_size);
-}
-
-efi_status_t efi_load_initrd_dev_path(unsigned long *load_addr,
-				      unsigned long *load_size,
-				      unsigned long max);
+efi_status_t efi_load_initrd(efi_loaded_image_t *image,
+			     unsigned long *load_addr,
+			     unsigned long *load_size,
+			     unsigned long soft_limit,
+			     unsigned long hard_limit);
 
 #endif

drivers/firmware/efi/libstub/x86-stub.c

@@ -755,17 +755,8 @@ unsigned long efi_main(efi_handle_t handle,
 	if (!efi_noinitrd) {
 		unsigned long addr, size;
 
-		status = efi_load_initrd_dev_path(&addr, &size, ULONG_MAX);
-		if (status == EFI_NOT_FOUND) {
-			if (efi_is_native() && image != NULL) {
-				status = efi_load_initrd(image, &addr, &size,
-							 hdr->initrd_addr_max,
-							 ULONG_MAX);
-			} else {
-				addr = size = 0;
-				status = EFI_SUCCESS;
-			}
-		}
+		status = efi_load_initrd(image, &addr, &size,
+					 hdr->initrd_addr_max, ULONG_MAX);
 
 		if (status != EFI_SUCCESS) {
 			efi_err("Failed to load initrd!\n");