diff options
Diffstat (limited to 'drivers/net/phy/linkmode.c')
| -rw-r--r-- | drivers/net/phy/linkmode.c | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/drivers/net/phy/linkmode.c b/drivers/net/phy/linkmode.c new file mode 100644 index 000000000000..f60560fe3499 --- /dev/null +++ b/drivers/net/phy/linkmode.c @@ -0,0 +1,95 @@ +// SPDX-License-Identifier: GPL-2.0+ +#include <linux/linkmode.h> + +/** + * linkmode_resolve_pause - resolve the allowable pause modes + * @local_adv: local advertisement in ethtool format + * @partner_adv: partner advertisement in ethtool format + * @tx_pause: pointer to bool to indicate whether transmit pause should be + * enabled. + * @rx_pause: pointer to bool to indicate whether receive pause should be + * enabled. + * + * Flow control is resolved according to our and the link partners + * advertisements using the following drawn from the 802.3 specs: + * Local device Link partner + * Pause AsymDir Pause AsymDir Result + * 0 X 0 X Disabled + * 0 1 1 0 Disabled + * 0 1 1 1 TX + * 1 0 0 X Disabled + * 1 X 1 X TX+RX + * 1 1 0 1 RX + */ +void linkmode_resolve_pause(const unsigned long *local_adv, + const unsigned long *partner_adv, + bool *tx_pause, bool *rx_pause) +{ + __ETHTOOL_DECLARE_LINK_MODE_MASK(m); + + linkmode_and(m, local_adv, partner_adv); + if (linkmode_test_bit(ETHTOOL_LINK_MODE_Pause_BIT, m)) { + *tx_pause = true; + *rx_pause = true; + } else if (linkmode_test_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT, m)) { + *tx_pause = linkmode_test_bit(ETHTOOL_LINK_MODE_Pause_BIT, + partner_adv); + *rx_pause = linkmode_test_bit(ETHTOOL_LINK_MODE_Pause_BIT, + local_adv); + } else { + *tx_pause = false; + *rx_pause = false; + } +} +EXPORT_SYMBOL_GPL(linkmode_resolve_pause); + +/** + * linkmode_set_pause - set the pause mode advertisement + * @advertisement: advertisement in ethtool format + * @tx: boolean from ethtool struct ethtool_pauseparam tx_pause member + * @rx: boolean from ethtool struct ethtool_pauseparam rx_pause member + * + * Configure the advertised Pause and Asym_Pause bits according to the + * capabilities of provided in @tx and @rx. + * + * We convert as follows: + * tx rx Pause AsymDir + * 0 0 0 0 + * 0 1 1 1 + * 1 0 0 1 + * 1 1 1 0 + * + * Note: this translation from ethtool tx/rx notation to the advertisement + * is actually very problematical. Here are some examples: + * + * For tx=0 rx=1, meaning transmit is unsupported, receive is supported: + * + * Local device Link partner + * Pause AsymDir Pause AsymDir Result + * 1 1 1 0 TX + RX - but we have no TX support. + * 1 1 0 1 Only this gives RX only + * + * For tx=1 rx=1, meaning we have the capability to transmit and receive + * pause frames: + * + * Local device Link partner + * Pause AsymDir Pause AsymDir Result + * 1 0 0 1 Disabled - but since we do support tx and rx, + * this should resolve to RX only. + * + * Hence, asking for: + * rx=1 tx=0 gives Pause+AsymDir advertisement, but we may end up + * resolving to tx+rx pause or only rx pause depending on + * the partners advertisement. + * rx=0 tx=1 gives AsymDir only, which will only give tx pause if + * the partners advertisement allows it. + * rx=1 tx=1 gives Pause only, which will only allow tx+rx pause + * if the other end also advertises Pause. + */ +void linkmode_set_pause(unsigned long *advertisement, bool tx, bool rx) +{ + linkmode_mod_bit(ETHTOOL_LINK_MODE_Pause_BIT, advertisement, rx); + linkmode_mod_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT, advertisement, + rx ^ tx); +} +EXPORT_SYMBOL_GPL(linkmode_set_pause); |