Saeed Mahameed says:
====================
mlx5-updates-2019-08-09
This series includes update to mlx5 ethernet and core driver:
In first #11 patches, Vlad submits part 2 of 3 part series to allow
TC flow handling for concurrent execution.
1) TC flow handling for concurrent execution (part 2)
Vald Says:
==========
Refactor data structures that are shared between flows in tc.
Currently, all cls API hardware offloads driver callbacks require caller
to hold rtnl lock when calling them. Cls API has already been updated to
update software filters in parallel (on classifiers that support
unlocked execution), however hardware offloads code still obtains rtnl
lock before calling driver tc callbacks. This set implements support for
unlocked execution of tc hairpin, mod_hdr and encap subsystem. The
changed implemented in these subsystems are very similar in general.
The main difference is that hairpin is accessed through mlx5e_tc_table
(legacy mode), mod_hdr is accessed through both mlx5e_tc_table and
mlx5_esw_offload (legacy and switchdev modes) and encap is only accessed
through mlx5_esw_offload (switchdev mode).
1.1) Hairpin handling and structure mlx5e_hairpin_entry refactored in
following way:
- Hairpin structure is extended with atomic reference counter. This
approach allows to lookup of hairpin entry and obtain reference to it
with hairpin_tbl_lock protection and then continue using the entry
unlocked (including provisioning to hardware).
- To support unlocked provisioning of hairpin entry to hardware, the entry
is extended with 'res_ready' completion and is inserted to hairpin_tbl
before calling the firmware. With this approach any concurrent users that
attempt to use the same hairpin entry wait for completion first to
prevent access to entries that are not fully initialized.
- Hairpin entry is extended with new flows_lock spinlock to protect the
list when multiple concurrent tc instances update flows attached to
the same hairpin entry.
1.2) Modify header handling code and structure mlx5e_mod_hdr_entry
are refactored in the following way:
- Mod_hdr structure is extended with atomic reference counter. This
approach allows to lookup of mod_hdr entry and obtain reference to it
with mod_hdr_tbl_lock protection and then continue using the entry
unlocked (including provisioning to hardware).
- To support unlocked provisioning of mod_hdr entry to hardware, the entry
is extended with 'res_ready' completion and is inserted to mod_hdr_tbl
before calling the firmware. With this approach any concurrent users that
attempt to use the same mod_hdr entry wait for completion first to
prevent access to entries that are not fully initialized.
- Mod_Hdr entry is extended with new flows_lock spinlock to protect the
list when multiple concurrent tc instances update flows attached to
the same mod_hdr entry.
1.3) Encapsulation handling code and Structure mlx5e_encap_entry
are refactored in the following way:
- encap structure is extended with atomic reference counter. This
approach allows to lookup of encap entry and obtain reference to it
with encap_tbl_lock protection and then continue using the entry
unlocked (including provisioning to hardware).
- To support unlocked provisioning of encap entry to hardware, the entry is
extended with 'res_ready' completion and is inserted to encap_tbl before
calling the firmware. With this approach any concurrent users that
attempt to use the same encap entry wait for completion first to prevent
access to entries that are not fully initialized.
- As a difference from approach used to refactor hairpin and mod_hdr,
encap entry is not extended with any per-entry fine-grained lock.
Instead, encap_table_lock is used to synchronize all operations on
encap table and instances of mlx5e_encap_entry. This is necessary
because single flow can be attached to multiple encap entries
simultaneously. During new flow creation or neigh update event all of
encaps that flow is attached to must be accessed together as in atomic
manner, which makes usage of per-entry lock infeasible.
- Encap entry is extended with new flows_lock spinlock to protect the
list when multiple concurrent tc instances update flows attached to
the same encap entry.
==========
3) Parav improves the way port representors report their parent ID and
port index.
4) Use refcount_t for refcount in vxlan data base from Chuhong Yuan
====================
Signed-off-by: David S. Miller <davem@davemloft.net>