1 files changed, 73 insertions, 1 deletions

diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c
index 757badc..919822b 100644
--- a/drivers/firmware/efi/libstub/efi-stub-helper.c
+++ b/drivers/firmware/efi/libstub/efi-stub-helper.c
@@ -338,6 +338,69 @@ void efi_free(efi_system_table_t *sys_table_arg, unsigned long size,
 	efi_call_early(free_pages, addr, nr_pages);
 }
 
+static efi_status_t efi_file_size(efi_system_table_t *sys_table_arg, void *__fh,
+				  efi_char16_t *filename_16, void **handle,
+				  u64 *file_sz)
+{
+	efi_file_handle_t *h, *fh = __fh;
+	efi_file_info_t *info;
+	efi_status_t status;
+	efi_guid_t info_guid = EFI_FILE_INFO_ID;
+	unsigned long info_sz;
+
+	status = efi_call_proto(efi_file_handle, open, fh, &h, filename_16,
+				EFI_FILE_MODE_READ, (u64)0);
+	if (status != EFI_SUCCESS) {
+		efi_printk(sys_table_arg, "Failed to open file: ");
+		efi_char16_printk(sys_table_arg, filename_16);
+		efi_printk(sys_table_arg, "\n");
+		return status;
+	}
+
+	*handle = h;
+
+	info_sz = 0;
+	status = efi_call_proto(efi_file_handle, get_info, h, &info_guid,
+				&info_sz, NULL);
+	if (status != EFI_BUFFER_TOO_SMALL) {
+		efi_printk(sys_table_arg, "Failed to get file info size\n");
+		return status;
+	}
+
+grow:
+	status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
+				info_sz, (void **)&info);
+	if (status != EFI_SUCCESS) {
+		efi_printk(sys_table_arg, "Failed to alloc mem for file info\n");
+		return status;
+	}
+
+	status = efi_call_proto(efi_file_handle, get_info, h, &info_guid,
+				&info_sz, info);
+	if (status == EFI_BUFFER_TOO_SMALL) {
+		efi_call_early(free_pool, info);
+		goto grow;
+	}
+
+	*file_sz = info->file_size;
+	efi_call_early(free_pool, info);
+
+	if (status != EFI_SUCCESS)
+		efi_printk(sys_table_arg, "Failed to get initrd info\n");
+
+	return status;
+}
+
+static efi_status_t efi_file_read(void *handle, unsigned long *size, void *addr)
+{
+	return efi_call_proto(efi_file_handle, read, handle, size, addr);
+}
+
+static efi_status_t efi_file_close(void *handle)
+{
+	return efi_call_proto(efi_file_handle, close, handle);
+}
+
 /*
  * Parse the ASCII string 'cmdline' for EFI options, denoted by the efi=
  * option, e.g. efi=nochunk.
@@ -351,6 +414,14 @@ efi_status_t efi_parse_options(char *cmdline)
 	char *str;
 
 	/*
+	 * Currently, the only efi= option we look for is 'nochunk', which
+	 * is intended to work around known issues on certain x86 UEFI
+	 * versions. So ignore for now on other architectures.
+	 */
+	if (!IS_ENABLED(CONFIG_X86))
+		return EFI_SUCCESS;
+
+	/*
 	 * If no EFI parameters were specified on the cmdline we've got
 	 * nothing to do.
 	 */
@@ -523,7 +594,8 @@ efi_status_t handle_cmdline_files(efi_system_table_t *sys_table_arg,
 			size = files[j].size;
 			while (size) {
 				unsigned long chunksize;
-				if (size > __chunk_size)
+
+				if (IS_ENABLED(CONFIG_X86) && size > __chunk_size)
 					chunksize = __chunk_size;
 				else
 					chunksize = size;