Index: uspace/drv/bus/usb/xhci/hw_struct/common.h
===================================================================
--- uspace/drv/bus/usb/xhci/hw_struct/common.h	(revision 51b26930c84c2241464ca1f71a493b6531980d4e)
+++ uspace/drv/bus/usb/xhci/hw_struct/common.h	(revision 51b26930c84c2241464ca1f71a493b6531980d4e)
@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2017 Ondrej Hlavaty
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** @addtogroup drvusbxhci
+ * @{
+ */
+/** @file
+ * @brief Common macros for HW structures.
+ *
+ * There are a lot of data structures that are defined on bit-basis.
+ * Therefore, we provide macros to define getters and setters.
+ */
+
+#ifndef XHCI_COMMON_H
+#define XHCI_COMMON_H
+
+#include <assert.h>
+#include <bitops.h>
+#include <ddi.h>
+#include <byteorder.h>
+
+#define host2xhci(size, val) host2uint##size##_t_le((val))
+#define xhci2host(size, val) uint##size##_t_le2host((val))
+
+/**
+ * 4 bytes, little-endian.
+ */
+typedef ioport32_t xhci_dword_t __attribute__((aligned(4)));
+
+/**
+ * 8 bytes, little-endian.
+ */
+typedef volatile uint64_t xhci_qword_t __attribute__((aligned(8)));
+
+#define XHCI_DWORD_EXTRACT(field, hi, lo) (BIT_RANGE_EXTRACT(uint32_t, hi, lo, xhci2host(32, field)))
+
+/**
+ * Common base for setters on xhci_dword_t storage.
+ *
+ * Not thread-safe, proper synchronization over this dword must be assured.
+ */
+static inline void xhci_dword_set_bits(xhci_dword_t *storage, uint32_t value, unsigned hi, unsigned lo)
+{
+	const uint32_t mask = host2xhci(32, BIT_RANGE(uint32_t, hi, lo));
+	const uint32_t set = host2xhci(32, value << lo);
+	*storage = (*storage & ~mask) | set;
+}
+
+/**
+ * Setter for whole qword.
+ */
+static inline void xhci_qword_set(xhci_qword_t *storage, uint64_t value)
+{
+	*storage = host2xhci(64, value);
+}
+
+#endif
+
+/**
+ * @}
+ */