efi: libstub: unify initrd loading between architectures

Use a EFI configuration table to pass the initrd to the core kernel,
instead of per-arch methods. This cleans up the code considerably, and
should make it easier for architectures to get rid of their reliance on
DT for doing EFI boot in the future.

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

1 files changed, 54 insertions, 45 deletions

diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c
index 63f3c2cd7058..a671eaad7503 100644
--- a/drivers/firmware/efi/libstub/efi-stub-helper.c
+++ b/drivers/firmware/efi/libstub/efi-stub-helper.c
@@ -550,20 +550,16 @@ static const struct {
  * * %EFI_SUCCESS if the initrd was loaded successfully, in which
  *   case @load_addr and @load_size are assigned accordingly
  * * %EFI_NOT_FOUND if no LoadFile2 protocol exists on the initrd device path
- * * %EFI_INVALID_PARAMETER if load_addr == NULL or load_size == NULL
  * * %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,
+efi_status_t efi_load_initrd_dev_path(struct linux_efi_initrd *initrd,
 				      unsigned long max)
 {
 	efi_guid_t lf2_proto_guid = EFI_LOAD_FILE2_PROTOCOL_GUID;
 	efi_device_path_protocol_t *dp;
 	efi_load_file2_protocol_t *lf2;
-	unsigned long initrd_addr;
-	unsigned long initrd_size;
 	efi_handle_t handle;
 	efi_status_t status;
 
@@ -577,42 +573,37 @@ efi_status_t efi_load_initrd_dev_path(unsigned long *load_addr,
 	if (status != EFI_SUCCESS)
 		return status;
 
-	status = efi_call_proto(lf2, load_file, dp, false, &initrd_size, NULL);
+	initrd->size = 0;
+	status = efi_call_proto(lf2, load_file, dp, false, &initrd->size, NULL);
 	if (status != EFI_BUFFER_TOO_SMALL)
 		return EFI_LOAD_ERROR;
 
-	status = efi_allocate_pages(initrd_size, &initrd_addr, max);
+	status = efi_allocate_pages(initrd->size, &initrd->base, max);
 	if (status != EFI_SUCCESS)
 		return status;
 
-	status = efi_call_proto(lf2, load_file, dp, false, &initrd_size,
-				(void *)initrd_addr);
+	status = efi_call_proto(lf2, load_file, dp, false, &initrd->size,
+				(void *)initrd->base);
 	if (status != EFI_SUCCESS) {
-		efi_free(initrd_size, initrd_addr);
+		efi_free(initrd->size, initrd->base);
 		return EFI_LOAD_ERROR;
 	}
-
-	*load_addr = initrd_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,
+				     struct linux_efi_initrd *initrd,
 				     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;
-	}
+	    (IS_ENABLED(CONFIG_X86) && (!efi_is_native() || image == NULL)))
+		return EFI_UNSUPPORTED;
 
 	return handle_cmdline_files(image, L"initrd=", sizeof(L"initrd=") - 2,
 				    soft_limit, hard_limit,
-				    load_addr, load_size);
+				    &initrd->base, &initrd->size);
 }
 
 static const struct {
@@ -659,42 +650,60 @@ static void efi_measure_initrd(unsigned long load_addr, unsigned long load_size)
 /**
  * efi_load_initrd() - Load initial RAM disk
  * @image:	EFI loaded image protocol
- * @load_addr:	pointer to loaded initrd
- * @load_size:	size of loaded initrd
  * @soft_limit:	preferred address for loading the initrd
  * @hard_limit:	upper limit address for loading the initrd
  *
  * Return:	status code
  */
 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)
+			     unsigned long hard_limit,
+			     const struct linux_efi_initrd **out)
 {
-	efi_status_t status;
+	efi_guid_t tbl_guid = LINUX_EFI_INITRD_MEDIA_GUID;
+	efi_status_t status = EFI_SUCCESS;
+	struct linux_efi_initrd initrd, *tbl;
 
-	if (efi_noinitrd) {
-		*load_addr = *load_size = 0;
-		status = EFI_SUCCESS;
-	} else {
-		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");
-			if (*load_size > 0)
-				efi_measure_initrd(*load_addr, *load_size);
-		} 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");
-		}
-		if (status != EFI_SUCCESS) {
-			efi_err("Failed to load initrd: 0x%lx\n", status);
-			*load_addr = *load_size = 0;
-		}
+	if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD) || efi_noinitrd)
+		return EFI_SUCCESS;
+
+	status = efi_load_initrd_dev_path(&initrd, hard_limit);
+	if (status == EFI_SUCCESS) {
+		efi_info("Loaded initrd from LINUX_EFI_INITRD_MEDIA_GUID device path\n");
+		if (initrd.size > 0)
+			efi_measure_initrd(initrd.base, initrd.size);
+	} else if (status == EFI_NOT_FOUND) {
+		status = efi_load_initrd_cmdline(image, &initrd, soft_limit,
+						 hard_limit);
+		/* command line loader disabled or no initrd= passed? */
+		if (status == EFI_UNSUPPORTED || status == EFI_NOT_READY)
+			return EFI_SUCCESS;
+		if (status == EFI_SUCCESS)
+			efi_info("Loaded initrd from command line option\n");
 	}
+	if (status != EFI_SUCCESS)
+		goto failed;
+
+	status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, sizeof(initrd),
+			     (void **)&tbl);
+	if (status != EFI_SUCCESS)
+		goto free_initrd;
+
+	*tbl = initrd;
+	status = efi_bs_call(install_configuration_table, &tbl_guid, tbl);
+	if (status != EFI_SUCCESS)
+		goto free_tbl;
+
+	if (out)
+		*out = tbl;
+	return EFI_SUCCESS;
 
+free_tbl:
+	efi_bs_call(free_pool, tbl);
+free_initrd:
+	efi_free(initrd.size, initrd.base);
+failed:
+	efi_err("Failed to load initrd: 0x%lx\n", status);
 	return status;
 }