target/linux/generic/backport-5.15/703-11-v5.17-net-phylink-add-pcs_validate-method.patch

   1 From 0d22d4b626a4eaa3196019092eb6c1919e9f8caa Mon Sep 17 00:00:00 2001
   2 From: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
   3 Date: Wed, 15 Dec 2021 15:34:20 +0000
   4 Subject: [PATCH] net: phylink: add pcs_validate() method
   5
   6 Add a hook for PCS to validate the link parameters. This avoids MAC
   7 drivers having to have knowledge of their PCS in their validate()
   8 method, thereby allowing several MAC drivers to be simplfied.
   9
  10 Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
  11 Signed-off-by: David S. Miller <davem@davemloft.net>
  12 ---
  13  drivers/net/phy/phylink.c | 31 +++++++++++++++++++++++++++++++
  14  include/linux/phylink.h   | 20 ++++++++++++++++++++
  15  2 files changed, 51 insertions(+)
  16
  17 --- a/drivers/net/phy/phylink.c
  18 +++ b/drivers/net/phy/phylink.c
  19 @@ -160,13 +160,44 @@ static int phylink_validate_mac_and_pcs(
  20                                         struct phylink_link_state *state)
  21  {
  22         struct phylink_pcs *pcs;
  23 +       int ret;
  24
  25 +       /* Get the PCS for this interface mode */
  26         if (pl->mac_ops->mac_select_pcs) {
  27                 pcs = pl->mac_ops->mac_select_pcs(pl->config, state->interface);
  28                 if (IS_ERR(pcs))
  29                         return PTR_ERR(pcs);
  30 +       } else {
  31 +               pcs = pl->pcs;
  32         }
  33
  34 +       if (pcs) {
  35 +               /* The PCS, if present, must be setup before phylink_create()
  36 +                * has been called. If the ops is not initialised, print an
  37 +                * error and backtrace rather than oopsing the kernel.
  38 +                */
  39 +               if (!pcs->ops) {
  40 +                       phylink_err(pl, "interface %s: uninitialised PCS\n",
  41 +                                   phy_modes(state->interface));
  42 +                       dump_stack();
  43 +                       return -EINVAL;
  44 +               }
  45 +
  46 +               /* Validate the link parameters with the PCS */
  47 +               if (pcs->ops->pcs_validate) {
  48 +                       ret = pcs->ops->pcs_validate(pcs, supported, state);
  49 +                       if (ret < 0 || phylink_is_empty_linkmode(supported))
  50 +                               return -EINVAL;
  51 +
  52 +                       /* Ensure the advertising mask is a subset of the
  53 +                        * supported mask.
  54 +                        */
  55 +                       linkmode_and(state->advertising, state->advertising,
  56 +                                    supported);
  57 +               }
  58 +       }
  59 +
  60 +       /* Then validate the link parameters with the MAC */
  61         pl->mac_ops->validate(pl->config, supported, state);
  62
  63         return phylink_is_empty_linkmode(supported) ? -EINVAL : 0;
  64 --- a/include/linux/phylink.h
  65 +++ b/include/linux/phylink.h
  66 @@ -398,6 +398,7 @@ struct phylink_pcs {
  67
  68  /**
  69   * struct phylink_pcs_ops - MAC PCS operations structure.
  70 + * @pcs_validate: validate the link configuration.
  71   * @pcs_get_state: read the current MAC PCS link state from the hardware.
  72   * @pcs_config: configure the MAC PCS for the selected mode and state.
  73   * @pcs_an_restart: restart 802.3z BaseX autonegotiation.
  74 @@ -405,6 +406,8 @@ struct phylink_pcs {
  75   *               (where necessary).
  76   */
  77  struct phylink_pcs_ops {
  78 +       int (*pcs_validate)(struct phylink_pcs *pcs, unsigned long *supported,
  79 +                           const struct phylink_link_state *state);
  80         void (*pcs_get_state)(struct phylink_pcs *pcs,
  81                               struct phylink_link_state *state);
  82         int (*pcs_config)(struct phylink_pcs *pcs, unsigned int mode,
  83 @@ -418,6 +421,23 @@ struct phylink_pcs_ops {
  84
  85  #if 0 /* For kernel-doc purposes only. */
  86  /**
  87 + * pcs_validate() - validate the link configuration.
  88 + * @pcs: a pointer to a &struct phylink_pcs.
  89 + * @supported: ethtool bitmask for supported link modes.
  90 + * @state: a const pointer to a &struct phylink_link_state.
  91 + *
  92 + * Validate the interface mode, and advertising's autoneg bit, removing any
  93 + * media ethtool link modes that would not be supportable from the supported
  94 + * mask. Phylink will propagate the changes to the advertising mask. See the
  95 + * &struct phylink_mac_ops validate() method.
  96 + *
  97 + * Returns -EINVAL if the interface mode/autoneg mode is not supported.
  98 + * Returns non-zero positive if the link state can be supported.
  99 + */
 100 +int pcs_validate(struct phylink_pcs *pcs, unsigned long *supported,
 101 +                const struct phylink_link_state *state);
 102 +
 103 +/**
 104   * pcs_get_state() - Read the current inband link state from the hardware
 105   * @pcs: a pointer to a &struct phylink_pcs.
 106   * @state: a pointer to a &struct phylink_link_state.