target/linux/generic/backport-6.6/715-24-v6.5-net-phylink-add-PCS-negotiation-mode.patch

   1 From 79b07c3e9c4a2272927be8848c26b372516e1958 Mon Sep 17 00:00:00 2001
   2 From: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
   3 Date: Fri, 16 Jun 2023 13:06:22 +0100
   4 Subject: [PATCH 21/21] net: phylink: add PCS negotiation mode
   5
   6 PCS have to work out whether they should enable PCS negotiation by
   7 looking at the "mode" and "interface" arguments, and the Autoneg bit
   8 in the advertising mask.
   9
  10 This leads to some complex logic, so lets pull that out into phylink
  11 and instead pass a "neg_mode" argument to the PCS configuration and
  12 link up methods, instead of the "mode" argument.
  13
  14 In order to transition drivers, add a "neg_mode" flag to the phylink
  15 PCS structure to PCS can indicate whether they want to be passed the
  16 neg_mode or the old mode argument.
  17
  18 Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
  19 Link: https://lore.kernel.org/r/E1qA8De-00EaFA-Ht@rmk-PC.armlinux.org.uk
  20 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
  21 ---
  22  drivers/net/phy/phylink.c |  45 +++++++++++++----
  23  include/linux/phylink.h   | 104 +++++++++++++++++++++++++++++++++++---
  24  2 files changed, 132 insertions(+), 17 deletions(-)
  25
  26 --- a/drivers/net/phy/phylink.c
  27 +++ b/drivers/net/phy/phylink.c
  28 @@ -71,6 +71,7 @@ struct phylink {
  29         struct mutex state_mutex;
  30         struct phylink_link_state phy_state;
  31         struct work_struct resolve;
  32 +       unsigned int pcs_neg_mode;
  33
  34         bool mac_link_dropped;
  35         bool using_mac_select_pcs;
  36 @@ -991,23 +992,23 @@ static void phylink_resolve_an_pause(str
  37         }
  38  }
  39
  40 -static int phylink_pcs_config(struct phylink_pcs *pcs, unsigned int mode,
  41 +static int phylink_pcs_config(struct phylink_pcs *pcs, unsigned int neg_mode,
  42                               const struct phylink_link_state *state,
  43                               bool permit_pause_to_mac)
  44  {
  45         if (!pcs)
  46                 return 0;
  47
  48 -       return pcs->ops->pcs_config(pcs, mode, state->interface,
  49 +       return pcs->ops->pcs_config(pcs, neg_mode, state->interface,
  50                                     state->advertising, permit_pause_to_mac);
  51  }
  52
  53 -static void phylink_pcs_link_up(struct phylink_pcs *pcs, unsigned int mode,
  54 +static void phylink_pcs_link_up(struct phylink_pcs *pcs, unsigned int neg_mode,
  55                                 phy_interface_t interface, int speed,
  56                                 int duplex)
  57  {
  58         if (pcs && pcs->ops->pcs_link_up)
  59 -               pcs->ops->pcs_link_up(pcs, mode, interface, speed, duplex);
  60 +               pcs->ops->pcs_link_up(pcs, neg_mode, interface, speed, duplex);
  61  }
  62
  63  static void phylink_pcs_poll_stop(struct phylink *pl)
  64 @@ -1057,10 +1058,15 @@ static void phylink_major_config(struct
  65         struct phylink_pcs *pcs = NULL;
  66         bool pcs_changed = false;
  67         unsigned int rate_kbd;
  68 +       unsigned int neg_mode;
  69         int err;
  70
  71         phylink_dbg(pl, "major config %s\n", phy_modes(state->interface));
  72
  73 +       pl->pcs_neg_mode = phylink_pcs_neg_mode(pl->cur_link_an_mode,
  74 +                                               state->interface,
  75 +                                               state->advertising);
  76 +
  77         if (pl->using_mac_select_pcs) {
  78                 pcs = pl->mac_ops->mac_select_pcs(pl->config, state->interface);
  79                 if (IS_ERR(pcs)) {
  80 @@ -1093,9 +1099,12 @@ static void phylink_major_config(struct
  81
  82         phylink_mac_config(pl, state);
  83
  84 -       err = phylink_pcs_config(pl->pcs, pl->cur_link_an_mode, state,
  85 -                                !!(pl->link_config.pause &
  86 -                                   MLO_PAUSE_AN));
  87 +       neg_mode = pl->cur_link_an_mode;
  88 +       if (pl->pcs && pl->pcs->neg_mode)
  89 +               neg_mode = pl->pcs_neg_mode;
  90 +
  91 +       err = phylink_pcs_config(pl->pcs, neg_mode, state,
  92 +                                !!(pl->link_config.pause & MLO_PAUSE_AN));
  93         if (err < 0)
  94                 phylink_err(pl, "pcs_config failed: %pe\n",
  95                             ERR_PTR(err));
  96 @@ -1130,6 +1139,7 @@ static void phylink_major_config(struct
  97   */
  98  static int phylink_change_inband_advert(struct phylink *pl)
  99  {
 100 +       unsigned int neg_mode;
 101         int ret;
 102
 103         if (test_bit(PHYLINK_DISABLE_STOPPED, &pl->phylink_disable_state))
 104 @@ -1148,12 +1158,20 @@ static int phylink_change_inband_advert(
 105                     __ETHTOOL_LINK_MODE_MASK_NBITS, pl->link_config.advertising,
 106                     pl->link_config.pause);
 107
 108 +       /* Recompute the PCS neg mode */
 109 +       pl->pcs_neg_mode = phylink_pcs_neg_mode(pl->cur_link_an_mode,
 110 +                                       pl->link_config.interface,
 111 +                                       pl->link_config.advertising);
 112 +
 113 +       neg_mode = pl->cur_link_an_mode;
 114 +       if (pl->pcs->neg_mode)
 115 +               neg_mode = pl->pcs_neg_mode;
 116 +
 117         /* Modern PCS-based method; update the advert at the PCS, and
 118          * restart negotiation if the pcs_config() helper indicates that
 119          * the programmed advertisement has changed.
 120          */
 121 -       ret = phylink_pcs_config(pl->pcs, pl->cur_link_an_mode,
 122 -                                &pl->link_config,
 123 +       ret = phylink_pcs_config(pl->pcs, neg_mode, &pl->link_config,
 124                                  !!(pl->link_config.pause & MLO_PAUSE_AN));
 125         if (ret < 0)
 126                 return ret;
 127 @@ -1256,6 +1274,7 @@ static void phylink_link_up(struct phyli
 128                             struct phylink_link_state link_state)
 129  {
 130         struct net_device *ndev = pl->netdev;
 131 +       unsigned int neg_mode;
 132         int speed, duplex;
 133         bool rx_pause;
 134
 135 @@ -1286,8 +1305,12 @@ static void phylink_link_up(struct phyli
 136
 137         pl->cur_interface = link_state.interface;
 138
 139 -       phylink_pcs_link_up(pl->pcs, pl->cur_link_an_mode, pl->cur_interface,
 140 -                           speed, duplex);
 141 +       neg_mode = pl->cur_link_an_mode;
 142 +       if (pl->pcs && pl->pcs->neg_mode)
 143 +               neg_mode = pl->pcs_neg_mode;
 144 +
 145 +       phylink_pcs_link_up(pl->pcs, neg_mode, pl->cur_interface, speed,
 146 +                           duplex);
 147
 148         pl->mac_ops->mac_link_up(pl->config, pl->phydev, pl->cur_link_an_mode,
 149                                  pl->cur_interface, speed, duplex,
 150 --- a/include/linux/phylink.h
 151 +++ b/include/linux/phylink.h
 152 @@ -21,6 +21,24 @@ enum {
 153         MLO_AN_FIXED,   /* Fixed-link mode */
 154         MLO_AN_INBAND,  /* In-band protocol */
 155
 156 +       /* PCS "negotiation" mode.
 157 +        *  PHYLINK_PCS_NEG_NONE - protocol has no inband capability
 158 +        *  PHYLINK_PCS_NEG_OUTBAND - some out of band or fixed link setting
 159 +        *  PHYLINK_PCS_NEG_INBAND_DISABLED - inband mode disabled, e.g.
 160 +        *                                    1000base-X with autoneg off
 161 +        *  PHYLINK_PCS_NEG_INBAND_ENABLED - inband mode enabled
 162 +        * Additionally, this can be tested using bitmasks:
 163 +        *  PHYLINK_PCS_NEG_INBAND - inband mode selected
 164 +        *  PHYLINK_PCS_NEG_ENABLED - negotiation mode enabled
 165 +        */
 166 +       PHYLINK_PCS_NEG_NONE = 0,
 167 +       PHYLINK_PCS_NEG_ENABLED = BIT(4),
 168 +       PHYLINK_PCS_NEG_OUTBAND = BIT(5),
 169 +       PHYLINK_PCS_NEG_INBAND = BIT(6),
 170 +       PHYLINK_PCS_NEG_INBAND_DISABLED = PHYLINK_PCS_NEG_INBAND,
 171 +       PHYLINK_PCS_NEG_INBAND_ENABLED = PHYLINK_PCS_NEG_INBAND |
 172 +                                        PHYLINK_PCS_NEG_ENABLED,
 173 +
 174         /* MAC_SYM_PAUSE and MAC_ASYM_PAUSE are used when configuring our
 175          * autonegotiation advertisement. They correspond to the PAUSE and
 176          * ASM_DIR bits defined by 802.3, respectively.
 177 @@ -80,6 +98,70 @@ static inline bool phylink_autoneg_inban
 178  }
 179
 180  /**
 181 + * phylink_pcs_neg_mode() - helper to determine PCS inband mode
 182 + * @mode: one of %MLO_AN_FIXED, %MLO_AN_PHY, %MLO_AN_INBAND.
 183 + * @interface: interface mode to be used
 184 + * @advertising: adertisement ethtool link mode mask
 185 + *
 186 + * Determines the negotiation mode to be used by the PCS, and returns
 187 + * one of:
 188 + * %PHYLINK_PCS_NEG_NONE: interface mode does not support inband
 189 + * %PHYLINK_PCS_NEG_OUTBAND: an out of band mode (e.g. reading the PHY)
 190 + *   will be used.
 191 + * %PHYLINK_PCS_NEG_INBAND_DISABLED: inband mode selected but autoneg disabled
 192 + * %PHYLINK_PCS_NEG_INBAND_ENABLED: inband mode selected and autoneg enabled
 193 + *
 194 + * Note: this is for cases where the PCS itself is involved in negotiation
 195 + * (e.g. Clause 37, SGMII and similar) not Clause 73.
 196 + */
 197 +static inline unsigned int phylink_pcs_neg_mode(unsigned int mode,
 198 +                                               phy_interface_t interface,
 199 +                                               const unsigned long *advertising)
 200 +{
 201 +       unsigned int neg_mode;
 202 +
 203 +       switch (interface) {
 204 +       case PHY_INTERFACE_MODE_SGMII:
 205 +       case PHY_INTERFACE_MODE_QSGMII:
 206 +       case PHY_INTERFACE_MODE_QUSGMII:
 207 +       case PHY_INTERFACE_MODE_USXGMII:
 208 +               /* These protocols are designed for use with a PHY which
 209 +                * communicates its negotiation result back to the MAC via
 210 +                * inband communication. Note: there exist PHYs that run
 211 +                * with SGMII but do not send the inband data.
 212 +                */
 213 +               if (!phylink_autoneg_inband(mode))
 214 +                       neg_mode = PHYLINK_PCS_NEG_OUTBAND;
 215 +               else
 216 +                       neg_mode = PHYLINK_PCS_NEG_INBAND_ENABLED;
 217 +               break;
 218 +
 219 +       case PHY_INTERFACE_MODE_1000BASEX:
 220 +       case PHY_INTERFACE_MODE_2500BASEX:
 221 +               /* 1000base-X is designed for use media-side for Fibre
 222 +                * connections, and thus the Autoneg bit needs to be
 223 +                * taken into account. We also do this for 2500base-X
 224 +                * as well, but drivers may not support this, so may
 225 +                * need to override this.
 226 +                */
 227 +               if (!phylink_autoneg_inband(mode))
 228 +                       neg_mode = PHYLINK_PCS_NEG_OUTBAND;
 229 +               else if (linkmode_test_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
 230 +                                          advertising))
 231 +                       neg_mode = PHYLINK_PCS_NEG_INBAND_ENABLED;
 232 +               else
 233 +                       neg_mode = PHYLINK_PCS_NEG_INBAND_DISABLED;
 234 +               break;
 235 +
 236 +       default:
 237 +               neg_mode = PHYLINK_PCS_NEG_NONE;
 238 +               break;
 239 +       }
 240 +
 241 +       return neg_mode;
 242 +}
 243 +
 244 +/**
 245   * struct phylink_link_state - link state structure
 246   * @advertising: ethtool bitmask containing advertised link modes
 247   * @lp_advertising: ethtool bitmask containing link partner advertised link
 248 @@ -436,6 +518,7 @@ struct phylink_pcs_ops;
 249  /**
 250   * struct phylink_pcs - PHYLINK PCS instance
 251   * @ops: a pointer to the &struct phylink_pcs_ops structure
 252 + * @neg_mode: provide PCS neg mode via "mode" argument
 253   * @poll: poll the PCS for link changes
 254   *
 255   * This structure is designed to be embedded within the PCS private data,
 256 @@ -443,6 +526,7 @@ struct phylink_pcs_ops;
 257   */
 258  struct phylink_pcs {
 259         const struct phylink_pcs_ops *ops;
 260 +       bool neg_mode;
 261         bool poll;
 262  };
 263
 264 @@ -460,12 +544,12 @@ struct phylink_pcs_ops {
 265                             const struct phylink_link_state *state);
 266         void (*pcs_get_state)(struct phylink_pcs *pcs,
 267                               struct phylink_link_state *state);
 268 -       int (*pcs_config)(struct phylink_pcs *pcs, unsigned int mode,
 269 +       int (*pcs_config)(struct phylink_pcs *pcs, unsigned int neg_mode,
 270                           phy_interface_t interface,
 271                           const unsigned long *advertising,
 272                           bool permit_pause_to_mac);
 273         void (*pcs_an_restart)(struct phylink_pcs *pcs);
 274 -       void (*pcs_link_up)(struct phylink_pcs *pcs, unsigned int mode,
 275 +       void (*pcs_link_up)(struct phylink_pcs *pcs, unsigned int neg_mode,
 276                             phy_interface_t interface, int speed, int duplex);
 277  };
 278
 279 @@ -508,7 +592,7 @@ void pcs_get_state(struct phylink_pcs *p
 280  /**
 281   * pcs_config() - Configure the PCS mode and advertisement
 282   * @pcs: a pointer to a &struct phylink_pcs.
 283 - * @mode: one of %MLO_AN_FIXED, %MLO_AN_PHY, %MLO_AN_INBAND.
 284 + * @neg_mode: link negotiation mode (see below)
 285   * @interface: interface mode to be used
 286   * @advertising: adertisement ethtool link mode mask
 287   * @permit_pause_to_mac: permit forwarding pause resolution to MAC
 288 @@ -526,8 +610,12 @@ void pcs_get_state(struct phylink_pcs *p
 289   * For 1000BASE-X, the advertisement should be programmed into the PCS.
 290   *
 291   * For most 10GBASE-R, there is no advertisement.
 292 + *
 293 + * The %neg_mode argument should be tested via the phylink_mode_*() family of
 294 + * functions, or for PCS that set pcs->neg_mode true, should be tested
 295 + * against the %PHYLINK_PCS_NEG_* definitions.
 296   */
 297 -int pcs_config(struct phylink_pcs *pcs, unsigned int mode,
 298 +int pcs_config(struct phylink_pcs *pcs, unsigned int neg_mode,
 299                phy_interface_t interface, const unsigned long *advertising,
 300                bool permit_pause_to_mac);
 301
 302 @@ -543,7 +631,7 @@ void pcs_an_restart(struct phylink_pcs *
 303  /**
 304   * pcs_link_up() - program the PCS for the resolved link configuration
 305   * @pcs: a pointer to a &struct phylink_pcs.
 306 - * @mode: link autonegotiation mode
 307 + * @neg_mode: link negotiation mode (see below)
 308   * @interface: link &typedef phy_interface_t mode
 309   * @speed: link speed
 310   * @duplex: link duplex
 311 @@ -552,8 +640,12 @@ void pcs_an_restart(struct phylink_pcs *
 312   * the resolved link parameters. For example, a PCS operating in SGMII
 313   * mode without in-band AN needs to be manually configured for the link
 314   * and duplex setting. Otherwise, this should be a no-op.
 315 + *
 316 + * The %mode argument should be tested via the phylink_mode_*() family of
 317 + * functions, or for PCS that set pcs->neg_mode true, should be tested
 318 + * against the %PHYLINK_PCS_NEG_* definitions.
 319   */
 320 -void pcs_link_up(struct phylink_pcs *pcs, unsigned int mode,
 321 +void pcs_link_up(struct phylink_pcs *pcs, unsigned int neg_mode,
 322                  phy_interface_t interface, int speed, int duplex);
 323  #endif
 324