net: ethernet: ti: Fix mixed module-builtin object

With CONFIG_TI_K3_AM65_CPSW_NUSS=y and CONFIG_TI_ICSSG_PRUETH=m,
k3-cppi-desc-pool.o is linked to a module and also to vmlinux even though
the expected CFLAGS are different between builtins and modules.

The build system is complaining about the following:

k3-cppi-desc-pool.o is added to multiple modules: icssg-prueth
ti-am65-cpsw-nuss

Introduce the new module, k3-cppi-desc-pool, to provide the common
functions to ti-am65-cpsw-nuss and icssg-prueth.

Fixes: 128d5874c082 ("net: ti: icssg-prueth: Add ICSSG ethernet driver")
Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
Link: https://lore.kernel.org/r/20231018064936.3146846-1-danishanwar@ti.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net: ethernet: ti: fix return value check in k3_cppi_desc_pool_create_name()

In case of error, the function gen_pool_create() returns NULL pointer
not ERR_PTR(). The IS_ERR() test in the return value check should be
replaced with NULL test.

Fixes: 93a76530316a ("net: ethernet: ti: introduce am65x/j721e gigabit eth subsystem driver")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ethernet: ti: introduce am65x/j721e gigabit eth subsystem driver

The TI AM65x/J721E SoCs Gigabit Ethernet Switch subsystem (CPSW2G NUSS) has
two ports - One Ethernet port (port 1) with selectable RGMII and RMII
interfaces and an internal Communications Port Programming Interface (CPPI)
port (Host port 0) and with ALE in between. It also contains
- Management Data Input/Output (MDIO) interface for physical layer device
(PHY) management;
- Updated Address Lookup Engine (ALE) module;
- (TBD) New version of Common platform time sync (CPTS) module.

On the TI am65x/J721E SoCs CPSW NUSS Ethernet subsystem into device MCU
domain named MCU_CPSW0.

Host Port 0 CPPI Packet Streaming Interface interface supports 8 TX
channels and one RX channels operating by TI am654 NAVSS Unified DMA
Peripheral Root Complex (UDMA-P) controller.

Introduced driver provides standard Linux net_device to user space and supports:
- ifconfig up/down
- MAC address configuration
- ethtool operation:
--driver
--change
--register-dump
--negotiate phy
--statistics
--set-eee phy
--show-ring
--show-channels
--set-channels
- net_device ioctl mii-control
- promisc mode

- rx checksum offload for non-fragmented IPv4/IPv6 TCP/UDP packets.
The CPSW NUSS can verify IPv4/IPv6 TCP/UDP packets checksum and fills
csum information for each packet in psdata[2] word:
- BIT(16) CHECKSUM_ERROR - indicates csum error
- BIT(17) FRAGMENT - indicates fragmented packet
- BIT(18) TCP_UDP_N - Indicates TCP packet was detected
- BIT(19) IPV6_VALID, BIT(20) IPV4_VALID - indicates IPv6/IPv4 packet
- BIT(15, 0) CHECKSUM_ADD - This is the value that was summed
during the checksum computation. This value is FFFFh for non fragmented
IPV4/6 UDP/TCP packets with no checksum error.

RX csum offload can be disabled:
ethtool -K <dev> rx-checksum on|off

- tx checksum offload support for IPv4/IPv6 TCP/UDP packets (J721E only).
TX csum HW offload can be enabled/disabled:
ethtool -K <dev> tx-checksum-ip-generic on|off

- multiq and switch between round robin/prio modes for cppi tx queues by
using Netdev private flag "p0-rx-ptype-rrobin" to switch between
Round Robin and Fixed priority modes:
# ethtool --show-priv-flags eth0
Private flags for eth0:
p0-rx-ptype-rrobin: on
# ethtool --set-priv-flags eth0 p0-rx-ptype-rrobin off

Number of TX DMA channels can be changed using "ethtool -L eth0 tx <N>".

- GRO support: the napi_gro_receive() and napi_complete_done() are used.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Tested-by: Murali Karicheri <m-karicheri2@ti.com>
Tested-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>