firewire: core: add tests for serialization/deserialization of phy config packet

In the protocol of IEEE 1394, phy configuration packet is broadcasted to
the bus to configure all PHYs residing on the bus. It includes two
purposes; selecting root node and optimizing gap count.

This commit adds some helper function to serialize/deserialize the
content of phy configuration packet, as well as some KUnit tests for it.

Link: https://lore.kernel.org/r/20240606235133.231543-2-o-takashi@sakamocchi.jpSigned-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>

drivers/firewire/packet-serdes-test.c

@@ -248,6 +248,29 @@ static void deserialize_phy_packet_self_id_extended(u32 quadlet, unsigned int *p
 	*has_more_packets = phy_packet_self_id_get_more_packets(quadlet);
 }
 
+static void serialize_phy_packet_phy_config(u32 *quadlet, unsigned int packet_identifier,
+					    unsigned int root_id, bool has_force_root_node,
+					    bool has_gap_count_optimization, unsigned int gap_count)
+{
+	phy_packet_set_packet_identifier(quadlet, packet_identifier);
+	phy_packet_phy_config_set_root_id(quadlet, root_id);
+	phy_packet_phy_config_set_force_root_node(quadlet, has_force_root_node);
+	phy_packet_phy_config_set_gap_count_optimization(quadlet, has_gap_count_optimization);
+	phy_packet_phy_config_set_gap_count(quadlet, gap_count);
+}
+
+static void deserialize_phy_packet_phy_config(u32 quadlet, unsigned int *packet_identifier,
+					      unsigned int *root_id, bool *has_force_root_node,
+					      bool *has_gap_count_optimization,
+					      unsigned int *gap_count)
+{
+	*packet_identifier = phy_packet_get_packet_identifier(quadlet);
+	*root_id = phy_packet_phy_config_get_root_id(quadlet);
+	*has_force_root_node = phy_packet_phy_config_get_force_root_node(quadlet);
+	*has_gap_count_optimization = phy_packet_phy_config_get_gap_count_optimization(quadlet);
+	*gap_count = phy_packet_phy_config_get_gap_count(quadlet);
+}
+
 static void test_async_header_write_quadlet_request(struct kunit *test)
 {
 	static const u32 expected[ASYNC_HEADER_QUADLET_COUNT] = {
@@ -811,6 +834,60 @@ static void test_phy_packet_self_id_zero_and_one(struct kunit *test)
 	KUNIT_EXPECT_MEMEQ(test, quadlets, expected, sizeof(expected));
 }
 
+static void test_phy_packet_phy_config_force_root_node(struct kunit *test)
+{
+	const u32 expected = 0x02800000;
+	u32 quadlet = 0;
+
+	unsigned int packet_identifier;
+	unsigned int root_id;
+	bool has_force_root_node;
+	bool has_gap_count_optimization;
+	unsigned int gap_count;
+
+	deserialize_phy_packet_phy_config(expected, &packet_identifier, &root_id,
+					  &has_force_root_node, &has_gap_count_optimization,
+					  &gap_count);
+
+	KUNIT_EXPECT_EQ(test, PHY_PACKET_PACKET_IDENTIFIER_PHY_CONFIG, packet_identifier);
+	KUNIT_EXPECT_EQ(test, 0x02, root_id);
+	KUNIT_EXPECT_TRUE(test, has_force_root_node);
+	KUNIT_EXPECT_FALSE(test, has_gap_count_optimization);
+	KUNIT_EXPECT_EQ(test, 0, gap_count);
+
+	serialize_phy_packet_phy_config(&quadlet, packet_identifier, root_id, has_force_root_node,
+					has_gap_count_optimization, gap_count);
+
+	KUNIT_EXPECT_EQ(test, quadlet, expected);
+}
+
+static void test_phy_packet_phy_config_gap_count_optimization(struct kunit *test)
+{
+	const u32 expected = 0x034f0000;
+	u32 quadlet = 0;
+
+	unsigned int packet_identifier;
+	unsigned int root_id;
+	bool has_force_root_node;
+	bool has_gap_count_optimization;
+	unsigned int gap_count;
+
+	deserialize_phy_packet_phy_config(expected, &packet_identifier, &root_id,
+					  &has_force_root_node, &has_gap_count_optimization,
+					  &gap_count);
+
+	KUNIT_EXPECT_EQ(test, PHY_PACKET_PACKET_IDENTIFIER_PHY_CONFIG, packet_identifier);
+	KUNIT_EXPECT_EQ(test, 0x03, root_id);
+	KUNIT_EXPECT_FALSE(test, has_force_root_node);
+	KUNIT_EXPECT_TRUE(test, has_gap_count_optimization);
+	KUNIT_EXPECT_EQ(test, 0x0f, gap_count);
+
+	serialize_phy_packet_phy_config(&quadlet, packet_identifier, root_id, has_force_root_node,
+					has_gap_count_optimization, gap_count);
+
+	KUNIT_EXPECT_EQ(test, quadlet, expected);
+}
+
 static struct kunit_case packet_serdes_test_cases[] = {
 	KUNIT_CASE(test_async_header_write_quadlet_request),
 	KUNIT_CASE(test_async_header_write_block_request),
@@ -825,6 +902,8 @@ static struct kunit_case packet_serdes_test_cases[] = {
 	KUNIT_CASE(test_phy_packet_self_id_zero_case0),
 	KUNIT_CASE(test_phy_packet_self_id_zero_case1),
 	KUNIT_CASE(test_phy_packet_self_id_zero_and_one),
+	KUNIT_CASE(test_phy_packet_phy_config_force_root_node),
+	KUNIT_CASE(test_phy_packet_phy_config_gap_count_optimization),
 	{}
 };
 

drivers/firewire/phy-packet-definitions.h

@@ -21,6 +21,61 @@ static inline void phy_packet_set_packet_identifier(u32 *quadlet, unsigned int p
 	*quadlet |= (packet_identifier << PACKET_IDENTIFIER_SHIFT) & PACKET_IDENTIFIER_MASK;
 }
 
+#define PHY_PACKET_PACKET_IDENTIFIER_PHY_CONFIG		0
+
+#define PHY_CONFIG_ROOT_ID_MASK				0x3f000000
+#define PHY_CONFIG_ROOT_ID_SHIFT			24
+#define PHY_CONFIG_FORCE_ROOT_NODE_MASK			0x00800000
+#define PHY_CONFIG_FORCE_ROOT_NODE_SHIFT		23
+#define PHY_CONFIG_GAP_COUNT_OPTIMIZATION_MASK		0x00400000
+#define PHY_CONFIG_GAP_COUNT_OPTIMIZATION_SHIFT		22
+#define PHY_CONFIG_GAP_COUNT_MASK			0x003f0000
+#define PHY_CONFIG_GAP_COUNT_SHIFT			16
+
+static inline unsigned int phy_packet_phy_config_get_root_id(u32 quadlet)
+{
+	return (quadlet & PHY_CONFIG_ROOT_ID_MASK) >> PHY_CONFIG_ROOT_ID_SHIFT;
+}
+
+static inline void phy_packet_phy_config_set_root_id(u32 *quadlet, unsigned int root_id)
+{
+	*quadlet &= ~PHY_CONFIG_ROOT_ID_MASK;
+	*quadlet |= (root_id << PHY_CONFIG_ROOT_ID_SHIFT) & PHY_CONFIG_ROOT_ID_MASK;
+}
+
+static inline bool phy_packet_phy_config_get_force_root_node(u32 quadlet)
+{
+	return (quadlet & PHY_CONFIG_FORCE_ROOT_NODE_MASK) >> PHY_CONFIG_FORCE_ROOT_NODE_SHIFT;
+}
+
+static inline void phy_packet_phy_config_set_force_root_node(u32 *quadlet, bool has_force_root_node)
+{
+	*quadlet &= ~PHY_CONFIG_FORCE_ROOT_NODE_MASK;
+	*quadlet |= (has_force_root_node << PHY_CONFIG_FORCE_ROOT_NODE_SHIFT) & PHY_CONFIG_FORCE_ROOT_NODE_MASK;
+}
+
+static inline bool phy_packet_phy_config_get_gap_count_optimization(u32 quadlet)
+{
+	return (quadlet & PHY_CONFIG_GAP_COUNT_OPTIMIZATION_MASK) >> PHY_CONFIG_GAP_COUNT_OPTIMIZATION_SHIFT;
+}
+
+static inline void phy_packet_phy_config_set_gap_count_optimization(u32 *quadlet, bool has_gap_count_optimization)
+{
+	*quadlet &= ~PHY_CONFIG_GAP_COUNT_OPTIMIZATION_MASK;
+	*quadlet |= (has_gap_count_optimization << PHY_CONFIG_GAP_COUNT_OPTIMIZATION_SHIFT) & PHY_CONFIG_GAP_COUNT_OPTIMIZATION_MASK;
+}
+
+static inline unsigned int phy_packet_phy_config_get_gap_count(u32 quadlet)
+{
+	return (quadlet & PHY_CONFIG_GAP_COUNT_MASK) >> PHY_CONFIG_GAP_COUNT_SHIFT;
+}
+
+static inline void phy_packet_phy_config_set_gap_count(u32 *quadlet, unsigned int gap_count)
+{
+	*quadlet &= ~PHY_CONFIG_GAP_COUNT_MASK;
+	*quadlet |= (gap_count << PHY_CONFIG_GAP_COUNT_SHIFT) & PHY_CONFIG_GAP_COUNT_MASK;
+}
+
 #define PHY_PACKET_PACKET_IDENTIFIER_SELF_ID		2
 
 #define SELF_ID_PHY_ID_MASK				0x3f000000