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  1. 27 Jul, 2018 3 commits
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  5. 25 Jul, 2018 7 commits
    • David S. Miller's avatar
      Merge branch 'mlxsw-Introduce-algorithmic-TCAM-support' · 756cd366
      David S. Miller authored 
      Ido Schimmel says:

====================
mlxsw: Introduce algorithmic TCAM support

The Spectrum-2 ASIC uses an algorithmic TCAM (A-TCAM) where multiple
exact matches lookups are performed instead of a single lookup as with
standard circuit TCAM (C-TCAM) memory. This allows for higher scale and
reduced power consumption.

The lookups are performed by masking a packet using different masks
(e.g., {dst_ip/24, ethtype}) defined for the region and looking for an
exact match. Eventually, the rule with the highest priority will be
picked.

Since the number of masks per-region is limited, the ASIC includes a
C-TCAM that can be used as a spill area for rules that do not fit into
the A-TCAM.

The driver currently uses a C-TCAM only mode which is similar to
Spectrum-1. However, this mode severely limits both the number of
supported ACL rules and the performance of the ACL lookup.

This patch set introduces initial support for the A-TCAM mode where the
C-TCAM is only used for rule spillage.

The first five patches add the registers and ASIC resources needed in
order to make use of the A-TCAM.

Next three patches are the "meat" and add the eRP core which is used to
manage the masks used by each ACL region. The individual commit messages
are lengthy and aim to thoroughly explain the subject.

The next seven patches perform small adjustments in the code and the
related data structures and are meant to prepare the code base to the
introduction of the A-TCAM in the last two patches.

Various A-TCAM optimization will be the focus of follow-up patch sets:

* Pruning - Used to reduce the number of lookups. Each rule will include
  a prune vector that indicates which masks should not be considered for
  further lookups as they cannot result in a higher priority match

* Bloom filter - Used to reduce the number of lookups. Before performing
  a lookup with a given mask the ASIC will consult a bloom filter
  (managed by the driver) that indicates whether a match might exist using
  the considered mask

* Masks aggregation - Used to increase scale and reduce lookups. Masks
  that only differ by up to eight consecutive bits (delta bits) can be
  aggregated into a single mask. The delta bits then become a part of the
  rule's key. For example, dst_ip/16 and dst_ip/17 can be represented as
  dst_ip/16 with a delta bit of one. Rules using the aggregated mask then
  specify whether the 17-th bit should be masked or not and its value
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      756cd366
    • Ido Schimmel's avatar
      mlxsw: spectrum_acl: Start using A-TCAM · a0a777b9
      Ido Schimmel authored 
      Now that all the pieces are in place we can start using the A-TCAM
instead of only using the C-TCAM. This allows for much higher scale and
better performance (to be improved further by follow-up patch sets).

Perform the integration with the A-TCAM and the eRP core by reverting
the changes introduced by "mlxsw: spectrum_acl: Enable C-TCAM only mode
in eRP core" and add calls from the C-TCAM code into the eRP core.
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Reviewed-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      a0a777b9
    • Ido Schimmel's avatar
      mlxsw: spectrum_acl: Add A-TCAM rule insertion and deletion · a8758b67
      Ido Schimmel authored 
      Implement rule insertion and deletion into the A-TCAM before we flip the
driver to start using the A-TCAM.

Rule insertion into the A-TCAM is very similar to C-TCAM, but there are
subtle differences between regions of different sizes (i.e., different
number of key blocks).

Specifically, as explained in "mlxsw: spectrum_acl: Allow encoding a
partial key", in 12 key blocks regions a rule is split into two and the
two halves of the rule are linked using a "large entry key ID".

Such differences are abstracted away by using different region
operations per region type.
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Reviewed-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      a8758b67
    • Ido Schimmel's avatar
      mlxsw: spectrum_acl: Pass C-TCAM region and entry to insert function · a20ff8eb
      Ido Schimmel authored 
      When A-TCAM will be used together with C-TCAM, the C-TCAM code will need
to call into the eRP core in order to get an eRP for an inserted entry.

The eRP core takes an A-TCAM region as one of its arguments, so pass the
C-TCAM region to the insertion function which will later allow us to
derive the A-TCAM region, given it contains the C-TCAM one.
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Reviewed-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      a20ff8eb
    • Ido Schimmel's avatar
      mlxsw: spectrum_acl: Add A-TCAM region initialization · 6d240650
      Ido Schimmel authored 
      Before we start using the A-TCAM we need to make sure the region is
properly initialized.

This includes the setting of its type (which affects the size of its eRP
table, for example) and its registration with the eRP core.
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Reviewed-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      6d240650
    • Ido Schimmel's avatar
      mlxsw: spectrum_acl: Make global TCAM resources available to regions · f58df510
      Ido Schimmel authored 
      Each TCAM region currently uses its own resources and there is no
sharing between the different regions.

This is going to change with A-TCAM as each region will need to allocate
an eRP table from the global eRP tables array.

Make the global TCAM resources available to each region by passing the
TCAM private data to the region initialization routine.
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Reviewed-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      f58df510
    • Ido Schimmel's avatar
      mlxsw: spectrum_acl: Encapsulate C-TCAM region in A-TCAM region · 57e56d36
      Ido Schimmel authored 
      In Spectrum-2 the C-TCAM is only used for rules that can't fit in the
A-TCAM due to a limited number of masks per A-TCAM region.

In addition, rules inserted into the C-TCAM may affect rules residing in
the A-TCAM, by clearing their C-TCAM prune bit.

The two regions are thus closely related and can be thought of as if the
C-TCAM region is encapsulated in the A-TCAM one.

Change the data structures to reflect that before introducing A-TCAM
support and make C-TCAM region initialization part of the A-TCAM region
initialization sequence.
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Reviewed-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      57e56d36
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