Add qemu 2.4.0

[kvmfornfv.git] / qemu / roms / ipxe / src / net / iobpad.c

diff --git a/qemu/roms/ipxe/src/net/iobpad.c b/qemu/roms/ipxe/src/net/iobpad.c
new file mode 100644 (file)
index 0000000..9cc8328
--- /dev/null
+++ b/qemu/roms/ipxe/src/net/iobpad.c
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+/**
+ * @file
+ *
+ * I/O buffer padding
+ *
+ */
+
+#include <string.h>
+#include <ipxe/iobuf.h>
+
+/**
+ * Pad I/O buffer
+ *
+ * @v iobuf            I/O buffer
+ * @v min_len          Minimum length
+ *
+ * This function pads and aligns I/O buffers, for devices that
+ * aren't capable of padding in hardware, or that require specific
+ * alignment in TX buffers.  The packet data will end up aligned to a
+ * multiple of @c IOB_ALIGN.
+ *
+ * @c min_len must not exceed @v IOB_ZLEN.
+ */
+void iob_pad ( struct io_buffer *iobuf, size_t min_len ) {
+       void *data;
+       size_t len;
+       size_t headroom;
+       signed int pad_len;
+
+       assert ( min_len <= IOB_ZLEN );
+
+       /* Move packet data to start of I/O buffer.  This will both
+        * align the data (since I/O buffers are aligned to
+        * IOB_ALIGN) and give us sufficient space for the
+        * zero-padding
+        */
+       data = iobuf->data;
+       len = iob_len ( iobuf );
+       headroom = iob_headroom ( iobuf );
+       iob_push ( iobuf, headroom );
+       memmove ( iobuf->data, data, len );
+       iob_unput ( iobuf, headroom );
+
+       /* Pad to minimum packet length */
+       pad_len = ( min_len - iob_len ( iobuf ) );
+       if ( pad_len > 0 )
+               memset ( iob_put ( iobuf, pad_len ), 0, pad_len );
+}