firewire: core: add common inline functions to serialize/deserialize asynchronous packet header

In both core and 1394 OHCI driver, some hard-coded values and macros are
used to serialize/deserialize the header of asynchronous packets. It is
inconvenient to reuse them.

This commit adds some helper inline functions with their tests for the
purpose.

Link: https://lore.kernel.org/r/20240428071347.409202-2-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

drivers/firewire/.kunitconfig

@@ -3,3 +3,4 @@ CONFIG_PCI=y
 CONFIG_FIREWIRE=y
 CONFIG_FIREWIRE_KUNIT_UAPI_TEST=y
 CONFIG_FIREWIRE_KUNIT_DEVICE_ATTRIBUTE_TEST=y
+CONFIG_FIREWIRE_KUNIT_PACKET_SERDES_TEST=y

drivers/firewire/Kconfig

@@ -50,6 +50,22 @@ config FIREWIRE_KUNIT_DEVICE_ATTRIBUTE_TEST
 	  For more information on KUnit and unit tests in general, refer
 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
 
+config FIREWIRE_KUNIT_PACKET_SERDES_TEST
+	tristate "KUnit tests for packet serialization/deserialization" if !KUNIT_ALL_TESTS
+	depends on FIREWIRE && KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  This builds the KUnit tests for packet serialization and
+	  deserialization.
+
+	  KUnit tests run during boot and output the results to the debug
+	  log in TAP format (https://testanything.org/). Only useful for
+	  kernel devs running KUnit test harness and are not for inclusion
+	  into a production build.
+
+	  For more information on KUnit and unit tests in general, refer
+	  to the KUnit documentation in Documentation/dev-tools/kunit/.
+
 config FIREWIRE_OHCI
 	tristate "OHCI-1394 controllers"
 	depends on PCI && FIREWIRE && MMU

drivers/firewire/Makefile

@@ -17,4 +17,7 @@ obj-$(CONFIG_FIREWIRE_NOSY) += nosy.o
 obj-$(CONFIG_PROVIDE_OHCI1394_DMA_INIT) += init_ohci1394_dma.o
 
 firewire-uapi-test-objs += uapi-test.o
+firewire-packet-serdes-test-objs += packet-serdes-test.o
+
 obj-$(CONFIG_FIREWIRE_KUNIT_UAPI_TEST) += firewire-uapi-test.o
+obj-$(CONFIG_FIREWIRE_KUNIT_PACKET_SERDES_TEST) += firewire-packet-serdes-test.o

drivers/firewire/packet-header-definitions.h

+// SPDX-License-Identifier: GPL-2.0-or-later
+//
+// packet-header-definitions.h - The definitions of header fields for IEEE 1394 packet.
+//
+// Copyright (c) 2024 Takashi Sakamoto
+
+#ifndef _FIREWIRE_PACKET_HEADER_DEFINITIONS_H
+#define _FIREWIRE_PACKET_HEADER_DEFINITIONS_H
+
+#define ASYNC_HEADER_QUADLET_COUNT		4
+
+#define ASYNC_HEADER_Q0_DESTINATION_SHIFT	16
+#define ASYNC_HEADER_Q0_DESTINATION_MASK	0xffff0000
+#define ASYNC_HEADER_Q0_TLABEL_SHIFT		10
+#define ASYNC_HEADER_Q0_TLABEL_MASK		0x0000fc00
+#define ASYNC_HEADER_Q0_RETRY_SHIFT		8
+#define ASYNC_HEADER_Q0_RETRY_MASK		0x00000300
+#define ASYNC_HEADER_Q0_TCODE_SHIFT		4
+#define ASYNC_HEADER_Q0_TCODE_MASK		0x000000f0
+#define ASYNC_HEADER_Q0_PRIORITY_SHIFT		0
+#define ASYNC_HEADER_Q0_PRIORITY_MASK		0x0000000f
+#define ASYNC_HEADER_Q1_SOURCE_SHIFT		16
+#define ASYNC_HEADER_Q1_SOURCE_MASK		0xffff0000
+#define ASYNC_HEADER_Q1_RCODE_SHIFT		12
+#define ASYNC_HEADER_Q1_RCODE_MASK		0x0000f000
+#define ASYNC_HEADER_Q1_RCODE_SHIFT		12
+#define ASYNC_HEADER_Q1_RCODE_MASK		0x0000f000
+#define ASYNC_HEADER_Q1_OFFSET_HIGH_SHIFT	0
+#define ASYNC_HEADER_Q1_OFFSET_HIGH_MASK	0x0000ffff
+#define ASYNC_HEADER_Q3_DATA_LENGTH_SHIFT	16
+#define ASYNC_HEADER_Q3_DATA_LENGTH_MASK	0xffff0000
+#define ASYNC_HEADER_Q3_EXTENDED_TCODE_SHIFT	0
+#define ASYNC_HEADER_Q3_EXTENDED_TCODE_MASK	0x0000ffff
+
+static inline unsigned int async_header_get_destination(const u32 header[ASYNC_HEADER_QUADLET_COUNT])
+{
+	return (header[0] & ASYNC_HEADER_Q0_DESTINATION_MASK) >> ASYNC_HEADER_Q0_DESTINATION_SHIFT;
+}
+
+static inline unsigned int async_header_get_tlabel(const u32 header[ASYNC_HEADER_QUADLET_COUNT])
+{
+	return (header[0] & ASYNC_HEADER_Q0_TLABEL_MASK) >> ASYNC_HEADER_Q0_TLABEL_SHIFT;
+}
+
+static inline unsigned int async_header_get_retry(const u32 header[ASYNC_HEADER_QUADLET_COUNT])
+{
+	return (header[0] & ASYNC_HEADER_Q0_RETRY_MASK) >> ASYNC_HEADER_Q0_RETRY_SHIFT;
+}
+
+static inline unsigned int async_header_get_tcode(const u32 header[ASYNC_HEADER_QUADLET_COUNT])
+{
+	return (header[0] & ASYNC_HEADER_Q0_TCODE_MASK) >> ASYNC_HEADER_Q0_TCODE_SHIFT;
+}
+
+static inline unsigned int async_header_get_priority(const u32 header[ASYNC_HEADER_QUADLET_COUNT])
+{
+	return (header[0] & ASYNC_HEADER_Q0_PRIORITY_MASK) >> ASYNC_HEADER_Q0_PRIORITY_SHIFT;
+}
+
+static inline unsigned int async_header_get_source(const u32 header[ASYNC_HEADER_QUADLET_COUNT])
+{
+	return (header[1] & ASYNC_HEADER_Q1_SOURCE_MASK) >> ASYNC_HEADER_Q1_SOURCE_SHIFT;
+}
+
+static inline unsigned int async_header_get_rcode(const u32 header[ASYNC_HEADER_QUADLET_COUNT])
+{
+	return (header[1] & ASYNC_HEADER_Q1_RCODE_MASK) >> ASYNC_HEADER_Q1_RCODE_SHIFT;
+}
+
+static inline u64 async_header_get_offset(const u32 header[ASYNC_HEADER_QUADLET_COUNT])
+{
+	u32 hi = (header[1] & ASYNC_HEADER_Q1_OFFSET_HIGH_MASK) >> ASYNC_HEADER_Q1_OFFSET_HIGH_SHIFT;
+	return (((u64)hi) << 32) | ((u64)header[2]);
+}
+
+static inline u32 async_header_get_quadlet_data(const u32 header[ASYNC_HEADER_QUADLET_COUNT])
+{
+	return header[3];
+}
+
+static inline unsigned int async_header_get_data_length(const u32 header[ASYNC_HEADER_QUADLET_COUNT])
+{
+	return (header[3] & ASYNC_HEADER_Q3_DATA_LENGTH_MASK) >> ASYNC_HEADER_Q3_DATA_LENGTH_SHIFT;
+}
+
+static inline unsigned int async_header_get_extended_tcode(const u32 header[ASYNC_HEADER_QUADLET_COUNT])
+{
+	return (header[3] & ASYNC_HEADER_Q3_EXTENDED_TCODE_MASK) >> ASYNC_HEADER_Q3_EXTENDED_TCODE_SHIFT;
+}
+
+static inline void async_header_set_destination(u32 header[ASYNC_HEADER_QUADLET_COUNT],
+						unsigned int destination)
+{
+	header[0] &= ~ASYNC_HEADER_Q0_DESTINATION_MASK;
+	header[0] |= (((u32)destination) << ASYNC_HEADER_Q0_DESTINATION_SHIFT) & ASYNC_HEADER_Q0_DESTINATION_MASK;
+}
+
+static inline void async_header_set_tlabel(u32 header[ASYNC_HEADER_QUADLET_COUNT],
+					   unsigned int tlabel)
+{
+	header[0] &= ~ASYNC_HEADER_Q0_TLABEL_MASK;
+	header[0] |= (((u32)tlabel) << ASYNC_HEADER_Q0_TLABEL_SHIFT) & ASYNC_HEADER_Q0_TLABEL_MASK;
+}
+
+static inline void async_header_set_retry(u32 header[ASYNC_HEADER_QUADLET_COUNT],
+					  unsigned int retry)
+{
+	header[0] &= ~ASYNC_HEADER_Q0_RETRY_MASK;
+	header[0] |= (((u32)retry) << ASYNC_HEADER_Q0_RETRY_SHIFT) & ASYNC_HEADER_Q0_RETRY_MASK;
+}
+
+static inline void async_header_set_tcode(u32 header[ASYNC_HEADER_QUADLET_COUNT],
+					  unsigned int tcode)
+{
+	header[0] &= ~ASYNC_HEADER_Q0_TCODE_MASK;
+	header[0] |= (((u32)tcode) << ASYNC_HEADER_Q0_TCODE_SHIFT) & ASYNC_HEADER_Q0_TCODE_MASK;
+}
+
+static inline void async_header_set_priority(u32 header[ASYNC_HEADER_QUADLET_COUNT],
+					     unsigned int priority)
+{
+	header[0] &= ~ASYNC_HEADER_Q0_PRIORITY_MASK;
+	header[0] |= (((u32)priority) << ASYNC_HEADER_Q0_PRIORITY_SHIFT) & ASYNC_HEADER_Q0_PRIORITY_MASK;
+}
+
+
+static inline void async_header_set_source(u32 header[ASYNC_HEADER_QUADLET_COUNT],
+					   unsigned int source)
+{
+	header[1] &= ~ASYNC_HEADER_Q1_SOURCE_MASK;
+	header[1] |= (((u32)source) << ASYNC_HEADER_Q1_SOURCE_SHIFT) & ASYNC_HEADER_Q1_SOURCE_MASK;
+}
+
+static inline void async_header_set_rcode(u32 header[ASYNC_HEADER_QUADLET_COUNT],
+					  unsigned int rcode)
+{
+	header[1] &= ~ASYNC_HEADER_Q1_RCODE_MASK;
+	header[1] |= (((u32)rcode) << ASYNC_HEADER_Q1_RCODE_SHIFT) & ASYNC_HEADER_Q1_RCODE_MASK;
+}
+
+static inline void async_header_set_offset(u32 header[ASYNC_HEADER_QUADLET_COUNT], u64 offset)
+{
+	u32 hi = (u32)(offset >> 32);
+	header[1] &= ~ASYNC_HEADER_Q1_OFFSET_HIGH_MASK;
+	header[1] |= (hi << ASYNC_HEADER_Q1_OFFSET_HIGH_SHIFT) & ASYNC_HEADER_Q1_OFFSET_HIGH_MASK;
+	header[2] = (u32)(offset & 0x00000000ffffffff);
+}
+
+static inline void async_header_set_quadlet_data(u32 header[ASYNC_HEADER_QUADLET_COUNT], u32 quadlet_data)
+{
+	header[3] = quadlet_data;
+}
+
+static inline void async_header_set_data_length(u32 header[ASYNC_HEADER_QUADLET_COUNT],
+						unsigned int data_length)
+{
+	header[3] &= ~ASYNC_HEADER_Q3_DATA_LENGTH_MASK;
+	header[3] |= (((u32)data_length) << ASYNC_HEADER_Q3_DATA_LENGTH_SHIFT) & ASYNC_HEADER_Q3_DATA_LENGTH_MASK;
+}
+
+static inline void async_header_set_extended_tcode(u32 header[ASYNC_HEADER_QUADLET_COUNT],
+						   unsigned int extended_tcode)
+{
+	header[3] &= ~ASYNC_HEADER_Q3_EXTENDED_TCODE_MASK;
+	header[3] |= (((u32)extended_tcode) << ASYNC_HEADER_Q3_EXTENDED_TCODE_SHIFT) & ASYNC_HEADER_Q3_EXTENDED_TCODE_MASK;
+}
+
+#endif // _FIREWIRE_PACKET_HEADER_DEFINITIONS_H