sfc: coding style cleanups in mcdi_port_common.c

The code recently moved into this file contained a number of coding style
issues, about which checkpatch and xmastree complained. Fix them.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

sfc: handle limited FEC support

If the reported PHY capabilities do not include a given FEC mode, don't
attempt to select that FEC mode anyway. If the user tries to set a mode
through ethtool that is not supported, return an error.
The _REQUESTED bits don't appear in the supported caps, but are implied
by the corresponding FEC bits.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

sfc: remove phy_op indirection

Originally there were several implementations of PHY operations for the
several different PHYs used on Falcon boards. But Falcon is now in a
separate driver, and all sfc NICs since then have had MCDI-managed PHYs.
Thus, there is no need to indirect through function pointers in
efx->phy_op; we can simply call the efx_mcdi_phy_* functions directly.

This also hooks up these functions for EF100, which was previously using
the dummy_phy_ops.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

sfc: move definition of EFX_MC_STATS_GENERATION_INVALID

Saves a whole #include from nic.c.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

sfc: commonise some MAC configuration code

Refactor it a little as we go, and introduce efx_mcdi_set_mtu() which we
will later use for ef100 to change MTU without touching other MAC settings.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

sfc: commonise MCDI MAC stats handling

Most of it was already declared in mcdi_port_common.h, so just move the
implementations to mcdi_port_common.c.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

sfc: move a couple more functions

Signed-off-by: Alexandru-Mihai Maftei <amaftei@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

sfc: move various functions

Signed-off-by: Alexandru-Mihai Maftei <amaftei@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

sfc: add new headers in preparation for code split

New headers contain prototypes of functions that will be common between
ef10 and upcoming driver.
Removed static modifier from the affected functions.
Some function prototypes were removed from existing headers.

Signed-off-by: Alexandru-Mihai Maftei <amaftei@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>