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  1. 07 Apr, 2016 21 commits
  3. 06 Apr, 2016 19 commits
    • Stefan Assmann's avatar
      e1000: call ndo_stop() instead of dev_close() when running offline selftest · 1f2f83f8
      Stefan Assmann authored 
      Calling dev_close() causes IFF_UP to be cleared which will remove the
interfaces routes and some addresses. That's probably not what the user
intended when running the offline selftest. Besides this does not happen
if the interface is brought down before the test, so the current
behaviour is inconsistent.
Instead call the net_device_ops ndo_stop function directly and avoid
touching IFF_UP at all.
Signed-off-by: default avatarStefan Assmann <sassmann@kpanic.de>
Tested-by: default avatarAaron Brown <aaron.f.brown@intel.com>
Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
      1f2f83f8
    • David S. Miller's avatar
      Merge branch 'mlxsw-dcb' · 58a01d4d
      David S. Miller authored 
      Jiri Pirko says:

====================
mlxsw: Introduce support for Data Center Bridging

Ido says:

This patchset introduces support for Quality of Service (QoS) as part of the
IEEE Data Center Bridiging (DCB) standards.

Patches 1-9 do the required device initialization. Specifically, patches 1-6
initialize the ports' headroom buffers, which are used at ingress to store
incoming packets while they go through the switch's pipeline. Patches 7-9
complete them by initializing the egress scheduling.

The pipeline mentioned above determines the packet's egress port(s) and
traffic class. Ideally, once out of the pipeline the packet moves to the
switch's shared buffer (to be introduced in Jiri's patchset, currently
default values are used) and scheduled for transmission according to its
traffic class. The egress scheduling is configured according to the 802.1Qaz
standard, which is part of the DCB infrastructure supported by Linux. This
is introduced in patches 10-12.

Even after going through the pipeline packets are not always eligible to
enter the shared buffer. This is determined by the amount of available space
and the quotas associated with the packet. However, if flow control is
enabled and the packet is associated with the lossless flow, then it will
stay in the headroom and won't be discarded. This is introduced in patches
13-17.

Please check individual commit messages for more info, as I tried to keep
them pretty detailed.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      58a01d4d
    • Ido Schimmel's avatar
      mlxsw: spectrum: Add IEEE 802.1Qbb PFC support · d81a6bdb
      Ido Schimmel authored 
      Implement the appropriate DCB ops and allow a user to configure certain
traffic classes as lossless.

The operation configures PFC for both the egress (respecting PFC frames)
and ingress (sending PFC frames) parts of the port.

At egress, when a PFC frame is received for a PFC enabled priority, then
all the priorities mapped to the same TC are stopped.

At ingress, the priority group (PG) buffers to which the enabled PFC
priorities are mapped are configured to be lossless. PFC frames will be
transmitted when the Xoff threshold is crossed.

The user-supplied delay parameter is used to determine the PG's size
according to the following formula:

PG_SIZE = PG_SIZE_LOSSY + delay * CELL_FACTOR + MTU

In the worst case scenario the delay will be made up of packets that
are all of size CELL_SIZE + 1, which means each packet will require
almost twice its true size when buffered in the switch. We therefore
multiply this value by the "cell factor", which is close to 2.

Another MTU is added in case the transmitting host already started
transmitting a maximum length frame when the PFC packet was received.

As with PAUSE enabled ports, when the port's MTU is changed both the
PGs' size and threshold are adjusted accordingly.
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      d81a6bdb
    • Ido Schimmel's avatar
      mlxsw: reg: Introduce per priority counters · 34dba0a5
      Ido Schimmel authored 
      We are going to add support for PFC as part of DCB ops, which requires us
to report the number of PFC frames sent and received per priority.

Add per priority counters in order to report number of PFC frames sent
and received per priority.
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      34dba0a5
    • Ido Schimmel's avatar
      mlxsw: spectrum: Add support for PAUSE frames · 9f7ec052
      Ido Schimmel authored 
      When a packet ingress the switch it's placed in its assigned priority
group (PG) buffer in the port's headroom buffer while it goes through
the switch's pipeline. After going through the pipeline - which
determines its egress port(s) and traffic class - it's moved to the
switch's shared buffer awaiting transmission.

However, some packets are not eligible to enter the shared buffer due to
exceeded quotas or insufficient space. Marking their associated PGs as
lossless will cause the packets to accumulate in the PG buffer. Another
reason for packets accumulation are complicated pipelines (e.g.
involving a lot of ACLs).

To prevent packets from being dropped a user can enable PAUSE frames on
the port. This will mark all the active PGs as lossless and set their
size according to the maximum delay, as it's not configured by user.

                         +----------------+   +
                         |                |   |
                         |                |   |
                         |                |   |
                         |                |   |
                         |                |   |
                         |                |   | Delay
                         |                |   |
                         |                |   |
                         |                |   |
                         |                |   |
                         |                |   |
    Xon/Xoff threshold   +----------------+   +
                         |                |   |
                         |                |   | 2 * MTU
                         |                |   |
                         +----------------+   +

The delay (612 [Cells]) was calculated according to worst-case scenario
involving maximum MTU and 100m cables.

After marking the PGs as lossless the device is configured to respect
incoming PAUSE frames (Rx PAUSE) and generate PAUSE frames (Tx PAUSE)
according to user's settings.

Whenever the port's headroom configuration changes we take into account
the PAUSE configuration, so that we correctly set the PG's type (lossy /
lossless), size and threshold. This can happen when:

a) The port's MTU changes, as it directly affects the PG's size.

b) A PG is created following user configuration, by binding a priority
to it.

Note that the relevant SUPPORTED flags were already mistakenly set by
the driver before this commit.
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      9f7ec052
    • Ido Schimmel's avatar
      mlxsw: reg: Add lossless settings for PBMC register · 155f9de2
      Ido Schimmel authored 
      When configuring PAUSE frames and PFC we'll need to configure the
Xon/Xoff threshold for the priority group (PG) buffers.

Add the Xon/Xoff threshold fields to the PBMC register so that we can
configure these when needed.
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      155f9de2
    • Ido Schimmel's avatar
      mlxsw: reg: Add Port Flow Control Configuration register · 6f253d83
      Ido Schimmel authored 
      Add the Port Flow Control Configuration (PFCC) register, which
configures both flow control and Priority-based Flow Control (PFC).
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      6f253d83
    • Ido Schimmel's avatar
      mlxsw: spectrum: Allow setting maximum rate for a TC · cc7cf517
      Ido Schimmel authored 
      Allow a user to set maximum rate for a particular TC using DCB ops.
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      cc7cf517
    • Ido Schimmel's avatar
      mlxsw: spectrum: Add IEEE 802.1Qaz ETS support · 8e8dfe9f
      Ido Schimmel authored 
      Implement the appropriate DCB ops and allow a user to configure:
	* Priority to traffic class (TC) mapping with a total of 8
	  supported TCs
	* Transmission selection algorithm (TSA) for each TC and the
	  corresponding weights in case of weighted round robin (WRR)

As previously explained, we treat the priority group (PG) buffer in the
port's headroom as the ingress counterpart of the egress TC. Therefore,
when a certain priority to TC mapping is configured, we also configure
the port's headroom buffer.
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      8e8dfe9f
    • Ido Schimmel's avatar
      mlxsw: spectrum: Introduce support for Data Center Bridging (DCB) · f00817df
      Ido Schimmel authored 
      Introduce basic infrastructure for DCB and add the missing ops in
following patches.
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      f00817df
    • Ido Schimmel's avatar
      mlxsw: spectrum: Initialize egress scheduling · 90183b98
      Ido Schimmel authored 
      Before introducing support for DCB ops we should first make sure we
initialize the relevant parts in the device correctly. Specifically, the
egress scheduling.

The device supports a superset of the 802.1Qaz standard with 4 hierarchy
levels that can be linked to each other in multiple ways and with
different transmission selection algorithms (TSA) employed between them.

However, since we only intend to support the 802.1Qaz standard we
flatten the hierarchies and let the user configure via DCB ops the TSA
and max rate shaper at the subgroup hierarchy (see figure below) and the
mapping between switch priority to traffic class. By default, all switch
priorities are mapped to traffic class 0, strict priority is employed
and max shaper is disabled.

Default configuration:

         switch priority 0      ...         switch priority 7
                 +                                  +
                 |                                  |
                 +----------------------------------+
                 |
              +--v--+                          +-----+
Traffic Class |     |                          |     |
  Hierarchy   | TC0 |           ...            | TC7 |
              |     |                          |     |
              +--+--+                          +--+--+
                 |                                |
              +--v--+                          +--v--+
  Subgroup    | SG0 |                          | SG7 |
  Hierarchy   |     |                          |     |
              +-----+                          +-----+
              | TSA |                          | TSA |
              +-----+           ...            +-----+
              | MAX |                          | MAX |
              +--+--+                          +--+--+
                 |                                |
                 +---------------+----------------+
                                 |
                              +--v--+
                      Group   |     |
                    Hierarchy | GR0 |
                              |     |
                              +--+--+
                                 |
                              +--v--+
                      Port    |     |
                    Hierarchy | PR0 |
                              |     |
                              +-----+
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      90183b98
    • Ido Schimmel's avatar
      mlxsw: reg: Add QoS Switch Traffic Class Table register · 2c63a555
      Ido Schimmel authored 
      As part of DCB ops we'll have to configure the priority to traffic class
mapping of a port.

Add the QoS Switch Traffic Class Table (QTCT) register, which configures
the mapping between the packet switch priority and traffic class on the
transmit port.
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      2c63a555
    • Ido Schimmel's avatar
      mlxsw: reg: Add QoS ETS Element Configuration register · b9b7cee4
      Ido Schimmel authored 
      We are going to introduce support for DCB, so we need to be able to
configure the traffic selection algorithm (TSA) used by each traffic
class (TC), as well as the bandwidth percentage allocated to each TC in
case of ETS.

Add the QoS ETS Element Configuration register, which controls the
above parameters.
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      b9b7cee4
    • Ido Schimmel's avatar
      mlxsw: spectrum: Set port's shared buffer size to 0 · d6b7c13b
      Ido Schimmel authored 
      In addition to the priority group (PG) buffers in the headroom, the
device enables the allocation of headroom shared buffer, which can
be shared between different PGs.

However, we are not going to use the headroom shared buffer and instead
allow the user to use its size for PGs or the switch's shared buffer.
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      d6b7c13b
    • Ido Schimmel's avatar
      mlxsw: reg: Use correct PBMC register length · 7ad7cd61
      Ido Schimmel authored 
      The last field of the PBMC register is at offset 0x64 and its size is
0x8, so the correct register's length is 0x6C bytes.
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      7ad7cd61
    • Ido Schimmel's avatar
      mlxsw: spectrum: Correctly configure headroom size · ff6551ec
      Ido Schimmel authored 
      When packets ingress the switch they are assigned a switch priority and
directed to the corresponding priority group (PG) buffer in the port's
headroom buffer.

Since we now map all switch priorities to priority group 0 (PG0) by
default, there is no need to allocate the other priority groups during
initialization. The only exception is PG9, which is used for control
traffic.

At minimum, the PG should be able to store the currently classified
packet (pipeline latency isn't 0) and also the packets arriving during
the classification time. However, an incoming packet will not be
buffered if there is no available MTU-sized buffer space for storing it.

The buffer needed to accommodate for pipeline latency is variable and
needs to take into account both the current link speed and current
latency of the pipeline, which is time-dependent. Testing showed that
setting the PG's size to twice the current MTU is optimal.

Since PG9 is used strictly for control packets and not subject to flow
control, we are not going to resize it according to user configuration,
so we simply set it according to worst case scenario, which is twice the
maximum MTU.

In any case, later patches in the series will allow a user to direct
lossless flows to other PGs than PG0 and set their size to accommodate
for round-trip propagation delay.

The above change also requires us to resize the PG buffer whenever the
port's MTU is changed.
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      ff6551ec
    • Ido Schimmel's avatar
      mlxsw: spectrum: Add bytes to cells helper · 1a198449
      Ido Schimmel authored 
      Buffers in the switch store packets in units called buffer cells. Add a
helper to convert from bytes to cells, so that the actual number of
cells required (result is round up) is returned.

Also, drop the SB (shared buffer) acronym from the BYTES_PER_CELL macro,
as this unit is also used in the ports' buffers and not only the
switch's shared buffer.
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      1a198449
    • Ido Schimmel's avatar
      mlxsw: spectrum: Map all switch priorities to priority group 0 · dd6cb0f9
      Ido Schimmel authored 
      During transmission, the skb's priority is used to map the skb to a
traffic class, where the idea is to group priorities with similar
characteristics (e.g. lossy, lossless) to the same traffic class. By
default, all priorities are mapped to traffic class 0.

In the device, we model the skb's priority as the switch priority, which
is assigned to a packet according to its PCP value and ingress port
(untagged packets are assigned the port's default switch priority - 0).

At ingress, the packet is directed to a priority group (PG) buffer in
the port's headroom buffer according to the packet's switch priority and
switch priority to buffer mapping.

While it's possible to configure the egress mapping between skb's
priority (switch priority) and traffic class, there is no mechanism to
configure the ingress mapping to a PG.

In order to keep things simple and since grouping certain priorities into
a traffic class at egress also implies they should be grouped the same
at ingress, treat a PG as the ingress counterpart of an egress traffic
class.

Having established the above, during initialization map all the switch
priorities to PG0 in accordance with the Linux defaults for traffic
class mapping.
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      dd6cb0f9
    • Ido Schimmel's avatar
      mlxsw: reg: Add Port Prio To Buffer register · b98ff151
      Ido Schimmel authored 
      When packets ingress the switch they are assigned a switch priority
number that dictates the packet's priority group (PG) buffer in the
port's headroom buffer.

Add the Port Prio To Buffer (PPTB) register, which configures the switch
priority to PG mapping.
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      b98ff151
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