net: microchip: sparx5: correctly free skb in xmit

consume_skb on transmitted, kfree_skb on dropped, do not free on
TX_BUSY.

Previously the xmit function could return -EBUSY without freeing, which
supposedly is interpreted as a drop. And was using kfree on successfully
transmitted packets.

sparx5_fdma_xmit and sparx5_inject returns error code, where -EBUSY
indicates TX_BUSY and any other error code indicates dropped.

Fixes: f3cad2611a77 ("net: sparx5: add hostmode with phylink support")
Signed-off-by: Casper Andersson <casper.casan@gmail.com>
Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

eth: switch to netif_napi_add_weight()

Switch all Ethernet drivers which use custom napi weights
to the new API.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: sparx5: switchdev: fix possible NULL pointer dereference

As the possible failure of the allocation, devm_kzalloc() may return NULL
pointer.
Therefore, it should be better to check the 'db' in order to prevent
the dereference of NULL pointer.

Fixes: 10615907e9b51 ("net: sparx5: switchdev: adding frame DMA functionality")
Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: sparx5: Update extraction/injection for timestamping

Update both the extraction and injection to do timestamping of the
frames. The extraction is always doing the timestamping while for
injection is doing the timestamping only if it is configured.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: sparx5: switchdev: adding frame DMA functionality

This add frame DMA functionality to the Sparx5 platform.

Ethernet frames can be extracted or injected autonomously to or from the
device’s DDR3/DDR3L memory and/or PCIe memory space. Linked list data
structures in memory are used for injecting or extracting Ethernet frames.
The FDMA generates interrupts when frame extraction or injection is done
and when the linked lists need updating.

The FDMA implements two extraction channels, one per switch core port
towards the VCore CPU system and a total of six injection channels.
Extraction channels are mapped one-to-one to the CPU ports, while injection
channels can be individually assigned to any CPU port.

- FDMA channel 0 through 5 corresponds to CPU port 0 injection direction
FDMA_CH_CFG[channel].CH_INJ_PORT is set to 0.
- FDMA channel 0 through 5 corresponds to CPU port 1 injection direction when
FDMA_CH_CFG[channel].CH_INJ_PORT is set to 1.
- FDMA channel 6 corresponds to CPU port 0 extraction direction.
- FDMA channel 7 corresponds to CPU port 1 extraction direction.

The FDMA implements a strict priority scheme among channels. Extraction
channels are prioritized over injection channels and secondarily channels
with higher channel number are prioritized over channels with lower number.
On the other hand, ports are being served on an equal-bandwidth principle
both on injection and extraction directions. The equal-bandwidth principle
will not force an equal bandwidth. Instead, it ensures that the ports
perform at their best considering the operating conditions.

When more than one injection channel is enabled for injection on the same
CPU port, priority determines which channel can inject data. Ownership
is re-arbitrated on frame boundaries.

The FDMA processes linked lists of DMA Control Block Structures (DCBs). The
DCBs have the same basic structure for both injection and extraction. A DCB
must be placed on a 64-bit word-aligned address in memory. Each DCB has a
per-channel configurable amount of associated data blocks in memory, where
the frame data is stored.

The data blocks that are used by extraction channels must be placed on
64-bit word aligned addresses in memory, and their length must be a
multiple of 128 bytes.

A DCB carries the pointer to the next DCB of the linked list, the INFO word
which holds information for the DCB, and a pair of status word and memory
pointer for every data block that it is associated with.

Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>