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sfc: support FEC configuration through ethtool
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As well as 'auto' and the forced 'off', 'rs' and 'baser' states, we also
 handle combinations of settings (since the fecparam->fec field is a
 bitmask), where auto|rs and auto|baser specify a preferred FEC mode but
 will fall back to the other if the cable or link partner doesn't support
 it.  rs|baser (with or without auto bit) means prefer FEC even where
 auto wouldn't use it, but let FW choose which encoding to use.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Edward Cree authored and David S. Miller committed Mar 14, 2018
1 parent f215347 commit 7f61e6c
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32 changes: 32 additions & 0 deletions drivers/net/ethernet/sfc/ethtool.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1488,6 +1488,36 @@ static int efx_ethtool_get_module_info(struct net_device *net_dev,
return ret;
}

static int efx_ethtool_get_fecparam(struct net_device *net_dev,
struct ethtool_fecparam *fecparam)
{
struct efx_nic *efx = netdev_priv(net_dev);
int rc;

if (!efx->phy_op || !efx->phy_op->get_fecparam)
return -EOPNOTSUPP;
mutex_lock(&efx->mac_lock);
rc = efx->phy_op->get_fecparam(efx, fecparam);
mutex_unlock(&efx->mac_lock);

return rc;
}

static int efx_ethtool_set_fecparam(struct net_device *net_dev,
struct ethtool_fecparam *fecparam)
{
struct efx_nic *efx = netdev_priv(net_dev);
int rc;

if (!efx->phy_op || !efx->phy_op->get_fecparam)
return -EOPNOTSUPP;
mutex_lock(&efx->mac_lock);
rc = efx->phy_op->set_fecparam(efx, fecparam);
mutex_unlock(&efx->mac_lock);

return rc;
}

const struct ethtool_ops efx_ethtool_ops = {
.get_drvinfo = efx_ethtool_get_drvinfo,
.get_regs_len = efx_ethtool_get_regs_len,
Expand Down Expand Up @@ -1523,4 +1553,6 @@ const struct ethtool_ops efx_ethtool_ops = {
.get_module_eeprom = efx_ethtool_get_module_eeprom,
.get_link_ksettings = efx_ethtool_get_link_ksettings,
.set_link_ksettings = efx_ethtool_set_link_ksettings,
.get_fecparam = efx_ethtool_get_fecparam,
.set_fecparam = efx_ethtool_set_fecparam,
};
150 changes: 150 additions & 0 deletions drivers/net/ethernet/sfc/mcdi_port.c
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Original file line number Diff line number Diff line change
Expand Up @@ -352,6 +352,64 @@ static void efx_mcdi_phy_decode_link(struct efx_nic *efx,
link_state->speed = speed;
}

/* The semantics of the ethtool FEC mode bitmask are not well defined,
* particularly the meaning of combinations of bits. Which means we get to
* define our own semantics, as follows:
* OFF overrides any other bits, and means "disable all FEC" (with the
* exception of 25G KR4/CR4, where it is not possible to reject it if AN
* partner requests it).
* AUTO on its own means use cable requirements and link partner autoneg with
* fw-default preferences for the cable type.
* AUTO and either RS or BASER means use the specified FEC type if cable and
* link partner support it, otherwise autoneg/fw-default.
* RS or BASER alone means use the specified FEC type if cable and link partner
* support it and either requests it, otherwise no FEC.
* Both RS and BASER (whether AUTO or not) means use FEC if cable and link
* partner support it, preferring RS to BASER.
*/
static u32 ethtool_fec_caps_to_mcdi(u32 ethtool_cap)
{
u32 ret = 0;

if (ethtool_cap & ETHTOOL_FEC_OFF)
return 0;

if (ethtool_cap & ETHTOOL_FEC_AUTO)
ret |= (1 << MC_CMD_PHY_CAP_BASER_FEC_LBN) |
(1 << MC_CMD_PHY_CAP_25G_BASER_FEC_LBN) |
(1 << MC_CMD_PHY_CAP_RS_FEC_LBN);
if (ethtool_cap & ETHTOOL_FEC_RS)
ret |= (1 << MC_CMD_PHY_CAP_RS_FEC_LBN) |
(1 << MC_CMD_PHY_CAP_RS_FEC_REQUESTED_LBN);
if (ethtool_cap & ETHTOOL_FEC_BASER)
ret |= (1 << MC_CMD_PHY_CAP_BASER_FEC_LBN) |
(1 << MC_CMD_PHY_CAP_25G_BASER_FEC_LBN) |
(1 << MC_CMD_PHY_CAP_BASER_FEC_REQUESTED_LBN) |
(1 << MC_CMD_PHY_CAP_25G_BASER_FEC_REQUESTED_LBN);
return ret;
}

/* Invert ethtool_fec_caps_to_mcdi. There are two combinations that function
* can never produce, (baser xor rs) and neither req; the implementation below
* maps both of those to AUTO. This should never matter, and it's not clear
* what a better mapping would be anyway.
*/
static u32 mcdi_fec_caps_to_ethtool(u32 caps, bool is_25g)
{
bool rs = caps & (1 << MC_CMD_PHY_CAP_RS_FEC_LBN),
rs_req = caps & (1 << MC_CMD_PHY_CAP_RS_FEC_REQUESTED_LBN),
baser = is_25g ? caps & (1 << MC_CMD_PHY_CAP_25G_BASER_FEC_LBN)
: caps & (1 << MC_CMD_PHY_CAP_BASER_FEC_LBN),
baser_req = is_25g ? caps & (1 << MC_CMD_PHY_CAP_25G_BASER_FEC_REQUESTED_LBN)
: caps & (1 << MC_CMD_PHY_CAP_BASER_FEC_REQUESTED_LBN);

if (!baser && !rs)
return ETHTOOL_FEC_OFF;
return (rs_req ? ETHTOOL_FEC_RS : 0) |
(baser_req ? ETHTOOL_FEC_BASER : 0) |
(baser == baser_req && rs == rs_req ? 0 : ETHTOOL_FEC_AUTO);
}

static int efx_mcdi_phy_probe(struct efx_nic *efx)
{
struct efx_mcdi_phy_data *phy_data;
Expand Down Expand Up @@ -438,6 +496,13 @@ static int efx_mcdi_phy_probe(struct efx_nic *efx)
MCDI_DWORD(outbuf, GET_LINK_OUT_FLAGS),
MCDI_DWORD(outbuf, GET_LINK_OUT_FCNTL));

/* Record the initial FEC configuration (or nearest approximation
* representable in the ethtool configuration space)
*/
efx->fec_config = mcdi_fec_caps_to_ethtool(caps,
efx->link_state.speed == 25000 ||
efx->link_state.speed == 50000);

/* Default to Autonegotiated flow control if the PHY supports it */
efx->wanted_fc = EFX_FC_RX | EFX_FC_TX;
if (phy_data->supported_cap & (1 << MC_CMD_PHY_CAP_AN_LBN))
Expand All @@ -458,6 +523,8 @@ int efx_mcdi_port_reconfigure(struct efx_nic *efx)
ethtool_linkset_to_mcdi_cap(efx->link_advertising) :
phy_cfg->forced_cap);

caps |= ethtool_fec_caps_to_mcdi(efx->fec_config);

return efx_mcdi_set_link(efx, caps, efx_get_mcdi_phy_flags(efx),
efx->loopback_mode, 0);
}
Expand Down Expand Up @@ -584,6 +651,8 @@ efx_mcdi_phy_set_link_ksettings(struct efx_nic *efx,
}
}

caps |= ethtool_fec_caps_to_mcdi(efx->fec_config);

rc = efx_mcdi_set_link(efx, caps, efx_get_mcdi_phy_flags(efx),
efx->loopback_mode, 0);
if (rc)
Expand All @@ -599,6 +668,85 @@ efx_mcdi_phy_set_link_ksettings(struct efx_nic *efx,
return 0;
}

static int efx_mcdi_phy_get_fecparam(struct efx_nic *efx,
struct ethtool_fecparam *fec)
{
MCDI_DECLARE_BUF(outbuf, MC_CMD_GET_LINK_OUT_V2_LEN);
u32 caps, active, speed; /* MCDI format */
bool is_25g = false;
size_t outlen;
int rc;

BUILD_BUG_ON(MC_CMD_GET_LINK_IN_LEN != 0);
rc = efx_mcdi_rpc(efx, MC_CMD_GET_LINK, NULL, 0,
outbuf, sizeof(outbuf), &outlen);
if (rc)
return rc;
if (outlen < MC_CMD_GET_LINK_OUT_V2_LEN)
return -EOPNOTSUPP;

/* behaviour for 25G/50G links depends on 25G BASER bit */
speed = MCDI_DWORD(outbuf, GET_LINK_OUT_V2_LINK_SPEED);
is_25g = speed == 25000 || speed == 50000;

caps = MCDI_DWORD(outbuf, GET_LINK_OUT_V2_CAP);
fec->fec = mcdi_fec_caps_to_ethtool(caps, is_25g);
/* BASER is never supported on 100G */
if (speed == 100000)
fec->fec &= ~ETHTOOL_FEC_BASER;

active = MCDI_DWORD(outbuf, GET_LINK_OUT_V2_FEC_TYPE);
switch (active) {
case MC_CMD_FEC_NONE:
fec->active_fec = ETHTOOL_FEC_OFF;
break;
case MC_CMD_FEC_BASER:
fec->active_fec = ETHTOOL_FEC_BASER;
break;
case MC_CMD_FEC_RS:
fec->active_fec = ETHTOOL_FEC_RS;
break;
default:
netif_warn(efx, hw, efx->net_dev,
"Firmware reports unrecognised FEC_TYPE %u\n",
active);
/* We don't know what firmware has picked. AUTO is as good a
* "can't happen" value as any other.
*/
fec->active_fec = ETHTOOL_FEC_AUTO;
break;
}

return 0;
}

static int efx_mcdi_phy_set_fecparam(struct efx_nic *efx,
const struct ethtool_fecparam *fec)
{
struct efx_mcdi_phy_data *phy_cfg = efx->phy_data;
u32 caps;
int rc;

/* Work out what efx_mcdi_phy_set_link_ksettings() would produce from
* saved advertising bits
*/
if (test_bit(ETHTOOL_LINK_MODE_Autoneg_BIT, efx->link_advertising))
caps = (ethtool_linkset_to_mcdi_cap(efx->link_advertising) |
1 << MC_CMD_PHY_CAP_AN_LBN);
else
caps = phy_cfg->forced_cap;

caps |= ethtool_fec_caps_to_mcdi(fec->fec);
rc = efx_mcdi_set_link(efx, caps, efx_get_mcdi_phy_flags(efx),
efx->loopback_mode, 0);
if (rc)
return rc;

/* Record the new FEC setting for subsequent set_link calls */
efx->fec_config = fec->fec;
return 0;
}

static int efx_mcdi_phy_test_alive(struct efx_nic *efx)
{
MCDI_DECLARE_BUF(outbuf, MC_CMD_GET_PHY_STATE_OUT_LEN);
Expand Down Expand Up @@ -977,6 +1125,8 @@ static const struct efx_phy_operations efx_mcdi_phy_ops = {
.remove = efx_mcdi_phy_remove,
.get_link_ksettings = efx_mcdi_phy_get_link_ksettings,
.set_link_ksettings = efx_mcdi_phy_set_link_ksettings,
.get_fecparam = efx_mcdi_phy_get_fecparam,
.set_fecparam = efx_mcdi_phy_set_fecparam,
.test_alive = efx_mcdi_phy_test_alive,
.run_tests = efx_mcdi_phy_run_tests,
.test_name = efx_mcdi_phy_test_name,
Expand Down
8 changes: 8 additions & 0 deletions drivers/net/ethernet/sfc/net_driver.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -627,6 +627,8 @@ static inline bool efx_link_state_equal(const struct efx_link_state *left,
* Serialised by the mac_lock.
* @get_link_ksettings: Get ethtool settings. Serialised by the mac_lock.
* @set_link_ksettings: Set ethtool settings. Serialised by the mac_lock.
* @get_fecparam: Get Forward Error Correction settings. Serialised by mac_lock.
* @set_fecparam: Set Forward Error Correction settings. Serialised by mac_lock.
* @set_npage_adv: Set abilities advertised in (Extended) Next Page
* (only needed where AN bit is set in mmds)
* @test_alive: Test that PHY is 'alive' (online)
Expand All @@ -645,6 +647,9 @@ struct efx_phy_operations {
struct ethtool_link_ksettings *cmd);
int (*set_link_ksettings)(struct efx_nic *efx,
const struct ethtool_link_ksettings *cmd);
int (*get_fecparam)(struct efx_nic *efx, struct ethtool_fecparam *fec);
int (*set_fecparam)(struct efx_nic *efx,
const struct ethtool_fecparam *fec);
void (*set_npage_adv) (struct efx_nic *efx, u32);
int (*test_alive) (struct efx_nic *efx);
const char *(*test_name) (struct efx_nic *efx, unsigned int index);
Expand Down Expand Up @@ -820,6 +825,8 @@ struct efx_rss_context {
* @mdio_bus: PHY MDIO bus ID (only used by Siena)
* @phy_mode: PHY operating mode. Serialised by @mac_lock.
* @link_advertising: Autonegotiation advertising flags
* @fec_config: Forward Error Correction configuration flags. For bit positions
* see &enum ethtool_fec_config_bits.
* @link_state: Current state of the link
* @n_link_state_changes: Number of times the link has changed state
* @unicast_filter: Flag for Falcon-arch simple unicast filter.
Expand Down Expand Up @@ -972,6 +979,7 @@ struct efx_nic {
enum efx_phy_mode phy_mode;

__ETHTOOL_DECLARE_LINK_MODE_MASK(link_advertising);
u32 fec_config;
struct efx_link_state link_state;
unsigned int n_link_state_changes;

Expand Down

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