[efi] Provide efi_devpath_len()

Signed-off-by: Michael Brown <mcb30@ipxe.org>

3 files changed, 15 insertions, 12 deletions

diff --git a/src/interface/efi/efi_debug.c b/src/interface/efi/efi_debug.c
index ed18ff92..069ca3fc 100644
--- a/src/interface/efi/efi_debug.c
+++ b/src/interface/efi/efi_debug.c
@@ -359,9 +359,6 @@ const __attribute__ (( pure )) char *
 efi_devpath_text ( EFI_DEVICE_PATH_PROTOCOL *path ) {
 	EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
 	static char text[256];
-	void *start;
-	void *end;
-	size_t max_len;
 	size_t len;
 	CHAR16 *wtext;
 
@@ -374,13 +371,8 @@ efi_devpath_text ( EFI_DEVICE_PATH_PROTOCOL *path ) {
 	/* If we have no DevicePathToText protocol then use a raw hex string */
 	if ( ! efidpt ) {
 		DBG ( "[No DevicePathToText]" );
-		start = path;
-		end = efi_devpath_end ( path );
-		len = ( end - start );
-		max_len = ( ( sizeof ( text ) - 1 /* NUL */ ) / 2 /* "xx" */ );
-		if ( len > max_len )
-			len = max_len;
-		base16_encode ( start, len, text, sizeof ( text ) );
+		len = efi_devpath_len ( path );
+		base16_encode ( path, len, text, sizeof ( text ) );
 		return text;
 	}
 
diff --git a/src/interface/efi/efi_snp.c b/src/interface/efi/efi_snp.c
index 2ff1e974..5729a39c 100644
--- a/src/interface/efi/efi_snp.c
+++ b/src/interface/efi/efi_snp.c
@@ -1033,8 +1033,7 @@ static int efi_snp_probe ( struct net_device *netdev ) {
 	}
 
 	/* Allocate the new device path */
-	path_end = efi_devpath_end ( path.path );
-	path_prefix_len = ( ( ( void * ) path_end ) - ( ( void * ) path.path ));
+	path_prefix_len = efi_devpath_len ( path.path );
 	snpdev->path = zalloc ( path_prefix_len + sizeof ( *macpath ) +
 				sizeof ( *path_end ) );
 	if ( ! snpdev->path ) {
diff --git a/src/interface/efi/efi_utils.c b/src/interface/efi/efi_utils.c
index 1bebaa56..4dc75414 100644
--- a/src/interface/efi/efi_utils.c
+++ b/src/interface/efi/efi_utils.c
@@ -51,6 +51,18 @@ EFI_DEVICE_PATH_PROTOCOL * efi_devpath_end ( EFI_DEVICE_PATH_PROTOCOL *path ) {
 }
 
 /**
+ * Find length of device path (excluding terminator)
+ *
+ * @v path		Path to device
+ * @ret path_len	Length of device path
+ */
+size_t efi_devpath_len ( EFI_DEVICE_PATH_PROTOCOL *path ) {
+	EFI_DEVICE_PATH_PROTOCOL *end = efi_devpath_end ( path );
+
+	return ( ( ( void * ) end ) - ( ( void * ) path ) );
+}
+
+/**
  * Locate parent device supporting a given protocol
  *
  * @v device		EFI device handle