net: airoha: Introduce Airoha NPU support

Packet Processor Engine (PPE) module available on EN7581 SoC populates
the PPE table with 5-tuples flower rules learned from traffic forwarded
between the GDM ports connected to the Packet Switch Engine (PSE) module.
The airoha_eth driver can enable hw acceleration of learned 5-tuples
rules if the user configure them in netfilter flowtable (netfilter
flowtable support will be added with subsequent patches).
airoha_eth driver configures and collects data from the PPE module via a
Network Processor Unit (NPU) RISC-V module available on the EN7581 SoC.
Introduce basic support for Airoha NPU module.

Tested-by: Sayantan Nandy <sayantan.nandy@airoha.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/airoha/Kconfig

@@ -7,9 +7,18 @@ config NET_VENDOR_AIROHA
 
 if NET_VENDOR_AIROHA
 
+config NET_AIROHA_NPU
+	tristate "Airoha NPU support"
+	select WANT_DEV_COREDUMP
+	select REGMAP_MMIO
+	help
+	  This driver supports Airoha Network Processor (NPU) available
+	  on the Airoha Soc family.
+
 config NET_AIROHA
 	tristate "Airoha SoC Gigabit Ethernet support"
 	depends on NET_DSA || !NET_DSA
+	select NET_AIROHA_NPU
 	select PAGE_POOL
 	help
 	  This driver supports the gigabit ethernet MACs in the

drivers/net/ethernet/airoha/Makefile

@@ -4,3 +4,4 @@
 #
 
 obj-$(CONFIG_NET_AIROHA) += airoha_eth.o
+obj-$(CONFIG_NET_AIROHA_NPU) += airoha_npu.o

drivers/net/ethernet/airoha/airoha_eth.h

@@ -240,6 +240,8 @@ struct airoha_eth {
 	unsigned long state;
 	void __iomem *fe_regs;
 
+	struct airoha_npu __rcu *npu;
+
 	struct reset_control_bulk_data rsts[AIROHA_MAX_NUM_RSTS];
 	struct reset_control_bulk_data xsi_rsts[AIROHA_MAX_NUM_XSI_RSTS];