octeontx2-pf: Fix graceful exit during PFC configuration failure

During PFC configuration failure the code was not handling a graceful
exit. This patch fixes the same and add proper code for a graceful exit.

Fixes: 99c969a83d82 ("octeontx2-pf: Add egress PFC support")
Signed-off-by: Suman Ghosh <sumang@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

cteonxt2-pf: Fix backpressure config for multiple PFC priorities to work simultaneously

MAC (CGX or RPM) asserts backpressure at TL3 or TL2 node of the egress
hierarchical scheduler tree depending on link level config done. If
there are multiple PFC priorities enabled at a time and for all such
flows to backoff, each priority will have to assert backpressure at
different TL3/TL2 scheduler nodes and these flows will need to submit
egress pkts to these nodes.

Current PFC configuration has an issue where in only one backpressure
scheduler node is being allocated which is resulting in only one PFC
priority to work. This patch fixes this issue.

Fixes: 99c969a83d82 ("octeontx2-pf: Add egress PFC support")
Signed-off-by: Suman Ghosh <sumang@marvell.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20230824081032.436432-4-sumang@marvell.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

octeontx2-pf: Fix PFC TX scheduler free

During PFC TX schedulers free, flag TXSCHQ_FREE_ALL was being set
which caused free up all schedulers other than the PFC schedulers.
This patch fixes that to free only the PFC Tx schedulers.

Fixes: 99c969a83d82 ("octeontx2-pf: Add egress PFC support")
Signed-off-by: Suman Ghosh <sumang@marvell.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20230824081032.436432-2-sumang@marvell.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

octeontx2-pf: Add egress PFC support

As of now all transmit queues transmit packets out of same scheduler
queue hierarchy. Due to this PFC frames sent by peer are not handled
properly, either all transmit queues are backpressured or none.
To fix this when user enables PFC for a given priority map relavant
transmit queue to a different scheduler queue hierarcy, so that
backpressure is applied only to the traffic egressing out of that TXQ.

Signed-off-by: Suman Ghosh <sumang@marvell.com>
Link: https://lore.kernel.org/r/20220830120304.158060-1-sumang@marvell.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

octeontx2-pf: PFC config support with DCBx

Data centric bridging designed to eliminate packet loss due to
queue overflow by adding enhancements to ethernet network such as
proprity flow control etc. This patch adds support for management
of Priority flow control(PFC) on Octeontx2 and CN10K interfaces.

To enable PFC for all priorities
dcb pfc set dev eth0 prio-pfc all:on/off

To enable PFC on selected priorites
dcb pfc set dev eth0 prio-pfc 0:on/off 1:on/off ..7:on/off

With the ntuple commands user can map Priority to receive queues.
On queue overflow NIX will assert backpressure such that PFC pause frames
are genarated with mapped priority.

To map priority 7 to Queue 1
ethtool -U eth0 flow-type ether dst xx:xx:xx:xx:xx:xx vlan 0xe00a
m 0x1fff queue 1

Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Signed-off-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>