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  1. 19 Jan, 2023 7 commits
    • Vladimir Oltean's avatar
      net: enetc: split ring resource allocation from assignment · f3ce29e1
      Vladimir Oltean authored 
      We have a few instances in the enetc driver where the ring resources
(BD ring iomem, software BD ring, software TSO headers, basically
everything except RX buffers) need to be reallocated. For example, when
RX timestamping is enabled, the RX BD format changes to an extended one
(twice as large).

Currently, this is done using a simplistic enetc_close() -> enetc_open()
procedure. But this is quite crude, since it also invokes phylink_stop()
-> phylink_start(), the link is lost, and a few seconds need to pass for
autoneg to complete again.

In fact it's bad also due to the improper (yolo) error checking. In case
we fail to allocate new resources, we've already freed the old ones, so
the interface is more or less stuck.

To avoid that, we need a system where reconfiguration is possible in a
way in which resources are allocated upfront. This means that there will
be a higher memory usage temporarily, but the assignment of resources to
rings can be done when both the old and new resources are still available.

Introduce a struct enetc_bdr_resource which holds the resources for a
ring, be it RX or TX. This structure duplicates a lot of fields from
struct enetc_bdr (and access to the same fields in the ring structure
was left duplicated, to not change cache characteristics in the fast
path).

When enetc_alloc_tx_resources() runs, it returns an array of resource
elements (one per TX ring), in addition to the existing priv->tx_res.
To populate priv->tx_res with that array, one must call
enetc_assign_tx_resources(), and this also frees the old resources.
Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      f3ce29e1
    • Vladimir Oltean's avatar
      net: enetc: bring "bool extended" to top-level in enetc_open() · d075db51
      Vladimir Oltean authored 
      Extended RX buffer descriptors are necessary if they carry RX
timestamps, which will be true when PTP timestamping is enabled.

Right now, the rx_ring->ext_en is set from the function that allocates
ring resources (enetc_alloc_rx_resources() -> enetc_alloc_rxbdr()), and
also used later, in enetc_setup_rxbdr(). It is also used in the
enetc_rxbd() and enetc_rxbd_next() fast path helpers.

We want to decouple resource allocation from BD ring setup, but both
procedures depend on BD size (extended or not). Move the "extended"
boolean to enetc_open() and pass it both to the RX allocation procedure
as well as to the RX ring setup procedure. The latter will set
rx_ring->ext_en from now on.
Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      d075db51
    • Vladimir Oltean's avatar
      net: enetc: drop redundant enetc_free_tx_frame() call from enetc_free_txbdr() · bbd6043f
      Vladimir Oltean authored 
      The call path in enetc_close() is:

enetc_close()
-> enetc_free_rxtx_rings()
   -> enetc_free_tx_ring()
      -> enetc_free_tx_frame()
-> enetc_free_tx_resources()
   -> enetc_free_txbdr()
      -> enetc_free_tx_frame()

The enetc_free_tx_frame() function is written such that the second call
exits without doing anything, but nonetheless, it is completely
redundant. Delete it. This makes the TX teardown path more similar to
the RX one, where rx_swbd freeing is done in enetc_free_rx_ring(), not
in enetc_free_rxbdr().
Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      bbd6043f
    • Vladimir Oltean's avatar
      net: enetc: rx_swbd and tx_swbd are never NULL in enetc_free_rxtx_rings() · 2c338710
      Vladimir Oltean authored 
      The call path in enetc_close() is:

enetc_close()
-> enetc_free_rxtx_rings()
   -> enetc_free_rx_ring()
      -> tests whether rx_ring->rx_swbd is NULL
   -> enetc_free_tx_ring()
      -> tests whether tx_ring->tx_swbd is NULL
-> enetc_free_rx_resources()
   -> enetc_free_rxbdr()
      -> sets rxr->rx_swbd to NULL
-> enetc_free_tx_resources()
   -> enetc_free_txbdr()
      -> setx txr->tx_swbd to NULL

From the above, it is clear that due to the function ordering, the
checks for NULL are redundant, since the software buffer descriptor
arrays have not yet been set to NULL. Drop these checks.
Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      2c338710
    • Vladimir Oltean's avatar
      net: enetc: create enetc_dma_free_bdr() · 0d6cfd0f
      Vladimir Oltean authored 
      This is a refactoring change which introduces the opposite function of
enetc_dma_alloc_bdr().
Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      0d6cfd0f
    • Vladimir Oltean's avatar
      net: enetc: set up RX ring indices from enetc_setup_rxbdr() · fbf1cff9
      Vladimir Oltean authored 
      There is only one place which needs to set up indices in the RX ring.
Be consistent with what was done in the TX path and do this in
enetc_setup_rxbdr().
Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      fbf1cff9
    • Vladimir Oltean's avatar
      net: enetc: set next_to_clean/next_to_use just from enetc_setup_txbdr() · 1cbf19c5
      Vladimir Oltean authored 
      enetc_alloc_txbdr() deals with allocating resources necessary for a TX
ring to work (the array of software BDs and the array of TSO headers).

The next_to_clean and next_to_use pointers are overwritten with proper
values which are read from hardware here:

enetc_open
-> enetc_alloc_tx_resources
   -> enetc_alloc_txbdr
      -> set to zero
-> enetc_setup_bdrs
   -> enetc_setup_txbdr
      -> read from hardware

So their initialization with zeroes is pointless and confusing.
Delete it.

Consequently, since enetc_setup_txbdr() has no opposite cleanup
function, also delete the resetting of these indices from
enetc_free_tx_ring().
Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
      1cbf19c5
  3. 18 Jan, 2023 33 commits
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