[PATCH v3 2/2] net: macb: Clean up macb_validate
From: Sean Anderson <hidden>
Date: 2021-10-12 19:48:10
Subsystem:
atmel macb ethernet driver, networking drivers, the rest · Maintainers:
Théo Lebrun, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
As the number of interfaces grows, the number of if statements grows
ever more unweildy. Clean everything up a bit by using a switch
statement. This reduces the number of if statements, and the number of
times the same condition is checked. No functional change intended.
Signed-off-by: Sean Anderson <redacted>
---
This patch was originally submitted as [1].
There is another approach which could be used here. We could do
something like
macb_set_mode(bp, mask, iface)
{
switch (iface) {
case 10GBASER:
if (...)
phylink_set_10g_modes(mask);
else
return -EINVAL;
break;
case GMII:
/* etc etc */
}
return 0;
}
macb_validate(...)
{
if (state->interface == PHY_INTERFACE_MODE_NA) {
macb_set_mode(bp, mask, PHY_INTERFACE_MODE_10GBASER);
macb_set_mode(bp, mask, PHY_INTERFACE_MODE_GMII);
macb_set_mode(bp, mask, PHY_INTERFACE_MODE_MII);
} else if (macb_set_mode(bp, mask, state->interface)) {
bitmap_zero(supported, __ETHTOOL_LINK_MODE_MASK_NBITS);
return;
}
/* etc etc */
}
which has the advantage of much cleaner logic in the switch statement.
[1] https://lore.kernel.org/netdev/20211004191527.1610759-9-sean.anderson@seco.com/ (local)
Changes in v3:
- Remove labels/gotos in favor of explicit zeroing. Hopefully this
better illustrates the "linear" flow of the logic.
- Add comment with overview of the flow of the logic.
Changes in v2:
- Fix polarity of `one` being inverted
- Only set gigabit modes for NA if macb_is_gem()
drivers/net/ethernet/cadence/macb_main.c | 105 ++++++++++++-----------
1 file changed, 55 insertions(+), 50 deletions(-)
diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index cb0f86544955..9b2173c37edb 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c@@ -510,33 +510,65 @@ static void macb_validate(struct phylink_config *config, unsigned long *supported, struct phylink_link_state *state) { + bool one = state->interface != PHY_INTERFACE_MODE_NA; struct net_device *ndev = to_net_dev(config->dev); __ETHTOOL_DECLARE_LINK_MODE_MASK(mask) = { 0, }; struct macb *bp = netdev_priv(ndev); - /* We only support MII, RMII, GMII, RGMII & SGMII. */ - if (state->interface != PHY_INTERFACE_MODE_NA && - state->interface != PHY_INTERFACE_MODE_MII && - state->interface != PHY_INTERFACE_MODE_RMII && - state->interface != PHY_INTERFACE_MODE_GMII && - state->interface != PHY_INTERFACE_MODE_SGMII && - state->interface != PHY_INTERFACE_MODE_10GBASER && - !phy_interface_mode_is_rgmii(state->interface)) { - bitmap_zero(supported, __ETHTOOL_LINK_MODE_MASK_NBITS); - return; - } - - if (!macb_is_gem(bp) && - (state->interface == PHY_INTERFACE_MODE_GMII || - state->interface == PHY_INTERFACE_MODE_SGMII || - phy_interface_mode_is_rgmii(state->interface))) { - bitmap_zero(supported, __ETHTOOL_LINK_MODE_MASK_NBITS); - return; - } - - if (state->interface == PHY_INTERFACE_MODE_10GBASER && - !(bp->caps & MACB_CAPS_HIGH_SPEED && - bp->caps & MACB_CAPS_PCS)) { + /* There are three major types of interfaces we support: + * - (R)MII supporting 10/100 Mbit/s + * - GMII, RGMII, and SGMII supporting 10/100/1000 Mbit/s + * - 10GBASER supporting 10 Gbit/s only + * Because GMII and MII both support 10/100, GMII falls through to MII. + * + * If we can't support an interface mode, we just clear the supported + * mask and return. The major complication is that if we get + * PHY_INTERFACE_MODE_NA, we must return all modes we support. Because + * of this, NA starts at the top of the switch and falls all the way to + * the bottom, and doesn't return early if we don't support a + * particular mode. + */ + switch (state->interface) { + case PHY_INTERFACE_MODE_NA: + case PHY_INTERFACE_MODE_10GBASER: + if (bp->caps & MACB_CAPS_HIGH_SPEED && + bp->caps & MACB_CAPS_PCS && + bp->caps & MACB_CAPS_GIGABIT_MODE_AVAILABLE) { + phylink_set_10g_modes(mask); + phylink_set(mask, 10000baseKR_Full); + } else if (one) { + bitmap_zero(supported, __ETHTOOL_LINK_MODE_MASK_NBITS); + return; + } + if (one) + break; + fallthrough; + case PHY_INTERFACE_MODE_GMII: + case PHY_INTERFACE_MODE_RGMII: + case PHY_INTERFACE_MODE_RGMII_ID: + case PHY_INTERFACE_MODE_RGMII_RXID: + case PHY_INTERFACE_MODE_RGMII_TXID: + case PHY_INTERFACE_MODE_SGMII: + if (macb_is_gem(bp)) { + if (bp->caps & MACB_CAPS_GIGABIT_MODE_AVAILABLE) { + phylink_set(mask, 1000baseT_Full); + phylink_set(mask, 1000baseX_Full); + if (!(bp->caps & MACB_CAPS_NO_GIGABIT_HALF)) + phylink_set(mask, 1000baseT_Half); + } + } else if (one) { + bitmap_zero(supported, __ETHTOOL_LINK_MODE_MASK_NBITS); + return; + } + fallthrough; + case PHY_INTERFACE_MODE_MII: + case PHY_INTERFACE_MODE_RMII: + phylink_set(mask, 10baseT_Half); + phylink_set(mask, 10baseT_Full); + phylink_set(mask, 100baseT_Half); + phylink_set(mask, 100baseT_Full); + break; + default: bitmap_zero(supported, __ETHTOOL_LINK_MODE_MASK_NBITS); return; }
@@ -544,33 +576,6 @@ static void macb_validate(struct phylink_config *config, phylink_set_port_modes(mask); phylink_set(mask, Autoneg); phylink_set(mask, Asym_Pause); - - if (bp->caps & MACB_CAPS_GIGABIT_MODE_AVAILABLE && - (state->interface == PHY_INTERFACE_MODE_NA || - state->interface == PHY_INTERFACE_MODE_10GBASER)) { - phylink_set_10g_modes(mask); - phylink_set(mask, 10000baseKR_Full); - if (state->interface != PHY_INTERFACE_MODE_NA) - goto out; - } - - phylink_set(mask, 10baseT_Half); - phylink_set(mask, 10baseT_Full); - phylink_set(mask, 100baseT_Half); - phylink_set(mask, 100baseT_Full); - - if (bp->caps & MACB_CAPS_GIGABIT_MODE_AVAILABLE && - (state->interface == PHY_INTERFACE_MODE_NA || - state->interface == PHY_INTERFACE_MODE_GMII || - state->interface == PHY_INTERFACE_MODE_SGMII || - phy_interface_mode_is_rgmii(state->interface))) { - phylink_set(mask, 1000baseT_Full); - phylink_set(mask, 1000baseX_Full); - - if (!(bp->caps & MACB_CAPS_NO_GIGABIT_HALF)) - phylink_set(mask, 1000baseT_Half); - } -out: bitmap_and(supported, supported, mask, __ETHTOOL_LINK_MODE_MASK_NBITS); bitmap_and(state->advertising, state->advertising, mask, __ETHTOOL_LINK_MODE_MASK_NBITS);
--
2.25.1