At present, ksz8795.c and ksz9477.c have separate dsa_switch_ops
structure initialization. This patch modifies the files such a way that
ksz switches has common dsa_switch_ops in the ksz_common.c file.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch moves the enabling the multicast storm protection from
individual setup function to ksz_setup function.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch move the 10% broadcast protection from the individual setup
to ksz_setup. In the ksz9477, broadcast protection is updated in reset
function.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch move the common initialization of switches to ksz_setup and
perform the switch specific initialization using the ksz_dev_ops
function pointer.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to transmit the STP BPDU packet to the CPU port, the STP
address 01-80-c2-00-00-00 has to be added to static alu table for
ksz8795 series switch. For the ksz9477 switch, there is reserved
multicast table which handles forwarding the particular set of
multicast address to cpu port. So enabling the multicast reserved table
and updated the cpu port index. The stp addr is enabled during the setup
phase using the enable_stp_addr pointer in struct ksz_dev_ops.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To have the common set of initialization in ksz_setup, introduced the
new config_cpu_port member to ksz_dev_ops. Since both the ksz8795.c and
ksz9477.c configuring the cpu port in the setup function, introduced the
member.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch renames the shutdown to reset in ksz_dev_ops in order to use
the reset dev_ops in the ksz_setup.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch assigns the get_phy_flags & mtu  hook of ksz8795 and ksz9477
in dsa_switch_ops to ksz_common.  For get_phy_flags hooks,checks whether
the chip is ksz8863/kss8793 then it returns error for port1.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>

This patch makes the dsa_switch_hook for fdbs to use ksz_common.c file.
And from ksz_common, individual switches fdb functions are called using
the dev->dev_ops. And removed the r_dyn_mac_table, r_sta_mac_table and
w_sta_mac_table from ksz_dev_ops as it is used only in ksz8795.c
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>

ksz_mdb_add/del in ksz_common.c is specific for the ksz8795.c file. The
ksz9477 has its separate ksz9477_port_mdb_add/del functions.  This patch
moves the ksz8795 specific mdb functionality from ksz_common to ksz8795.
And this dsa_switch_ops hooks for ksz8795/ksz9477 are invoked through
the ksz_port_mdb_add/del.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>

This patch assigns the phylink_get_caps in ksz8795 and ksz9477 to
ksz_phylink_get_caps. And update their mac_capabilities in the
respective ksz_dev_ops.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>

At present, P_STP_CTRL register value is passed as parameter to
ksz_port_stp_state from the individual dsa_switch_ops hooks. This patch
update the function to retrieve the register value through the
ksz_chip_data member.
And add the static to ksz_update_port_member since it is not called
outside the ksz_common.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>

This patch updates the common port mirror add/del dsa_switch_ops in
ksz_common.c. The individual switches implementation is executed based
on the ksz_dev_ops function pointers.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>

This patch moves the vlan dsa_switch_ops such as vlan_add, vlan_del and
vlan_filtering from the individual files ksz8795.c, ksz9477.c to
ksz_common.c file.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>

This patch move the dsa hook get_tag_protocol to ksz_common file. And
the tag_protocol is returned based on the dev->chip_id.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>

KSZ87xx and KSZ88xx have chip_id representation at reg location 0. And
KSZ9477 compatible switch and LAN937x switch have same chip_id detection
at location 0x01 and 0x02. To have the common switch detect
functionality for ksz switches, ksz_switch_detect function is
introduced.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>

The name, regs_size and overrides members in struct ksz_device are
unused. Hence remove it.
And host_mask is used in only place of ksz8795.c file, which can be
replaced by dev->info->cpu_ports
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch add the support for phylink_get_caps for ksz8795 and ksz9477
series switch. It updates the struct ksz_switch_chip with the details of
the internal phys and xmii interface. Then during the get_caps based on
the bits set in the structure, corresponding phy mode is set.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

mib->cnt_ptr resetting is handled in multiple places as part of
port_init_cnt(). Hence moved mib->cnt_ptr code to ksz common layer
and removed from individual product files.
Signed-off-by: NPrasanna Vengateshan <prasanna.vengateshan@microchip.com>
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ksz8795 and ksz9477 uses the same algorithm for copying the ethtool
strings. Hence moved to ksz_common to remove the redundant code.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ksz8795 and ksz9477 init function initializes the memory to dev->ports,
mib counters and assigns the ds real number of ports. Since both the
routines are same, moved the allocation of port memory to
ksz_switch_register after init.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ksz88xx family has one set of mib_names. The ksz87xx, ksz9477,
LAN937x based switches has one set of mib_names. In order to remove
redundant declaration, moved the struct mib_names to ksz_chip_data
structure.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch moves the ksz_chip_data in ksz8795 and ksz9477 to ksz_common.
At present, the dev->chip_id is iterated with the ksz_chip_data and then
copy its value to the ksz_dev structure. These values are declared as
constant.
Instead of copying the values and referencing it, this patch update the
dev->info to the ksz_chip_data based on the chip_id in the init
function. And also update the ksz_chip_data values for the LAN937x based
switches.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The port_cnt value in the structure is not used in the switch_init.
Instead it uses the fls(chip->cpu_port), this is due to one of port in
the ksz8794 unavailable. The cpu_port for the 8794 is 0x10, fls(0x10) =
5, hence updating it directly in the ksz_chip_data structure in order to
same with all the other switches in ksz8795.c and ksz9477.c files.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ksz8795 and ksz9477 uses the same algorithm for the
port_stp_state_set function except the register address is different. So
moved the algorithm to the ksz_common.c and used the dev_ops for
register read and write. This function can also used for the lan937x
part. Hence making it generic for all the parts.
Signed-off-by: NArun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20220424112831.11504-1-arun.ramadoss@microchip.comSigned-off-by: NPaolo Abeni <pabeni@redhat.com>

Drivers might have error messages to propagate to user space, most
common being that they support a single mirror port.

Propagate the netlink extack so that they can inform user space in a
verbal way of their limitations.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

According to erratum described in DS80000687C[1]: "Module 2: Link drops with
some EEE link partners.", we need to "Disable the EEE next page
exchange in EEE Global Register 2"

1 - https://ww1.microchip.com/downloads/en/DeviceDoc/KSZ87xx-Errata-DS80000687C.pdfSigned-off-by: NOleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20220316125529.1489045-1-o.rempel@pengutronix.deSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Populate the supported interfaces and MAC capabilities for the
Microchip KSZ8795 DSA switch and remove the old validate implementation
to allow DSA to use phylink_generic_validate() for this switch driver.
Signed-off-by: NRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sock.h is pretty heavily used (5k objects rebuilt on x86 after
it's touched). We can drop the include of filter.h from it and
add a forward declaration of struct sk_filter instead.
This decreases the number of rebuilt objects when bpf.h
is touched from ~5k to ~1k.

There's a lot of missing includes this was masking. Primarily
in networking tho, this time.
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NMarc Kleine-Budde <mkl@pengutronix.de>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Acked-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Acked-by: NStefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/bpf/20211229004913.513372-1-kuba@kernel.org

Current driver version is able to handle only one bridge at time.
Configuring two bridges on two different ports would end up shorting this
bridges by HW. To reproduce it:

	ip l a name br0 type bridge
	ip l a name br1 type bridge
	ip l s dev br0 up
	ip l s dev br1 up
	ip l s lan1 master br0
	ip l s dev lan1 up
	ip l s lan2 master br1
	ip l s dev lan2 up

	Ping on lan1 and get response on lan2, which should not happen.

This happened, because current driver version is storing one global "Port VLAN
Membership" and applying it to all ports which are members of any
bridge.
To solve this issue, we need to handle each port separately.

This patch is dropping the global port member storage and calculating
membership dynamically depending on STP state and bridge participation.

Note: STP support was broken before this patch and should be fixed
separately.

Fixes: c2e86691 ("net: dsa: microchip: break KSZ9477 DSA driver into two files")
Signed-off-by: NOleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20211126123926.2981028-1-o.rempel@pengutronix.deSigned-off-by: NJakub Kicinski <kuba@kernel.org>

This converts instances of
	bitmap_foo(args..., __ETHTOOL_LINK_MODE_MASK_NBITS)
to
	linkmode_foo(args...)

I manually fixed up some lines to prevent them from being excessively
long. Otherwise, this change was generated with the following semantic
patch:

// Generated with
// echo linux/linkmode.h > includes
// git grep -Flf includes include/ | cut -f 2- -d / | cat includes - \
// | sort | uniq | tee new_includes | wc -l && mv new_includes includes
// and repeating until the number stopped going up
@i@
@@

(
 #include <linux/acpi_mdio.h>
|
 #include <linux/brcmphy.h>
|
 #include <linux/dsa/loop.h>
|
 #include <linux/dsa/sja1105.h>
|
 #include <linux/ethtool.h>
|
 #include <linux/ethtool_netlink.h>
|
 #include <linux/fec.h>
|
 #include <linux/fs_enet_pd.h>
|
 #include <linux/fsl/enetc_mdio.h>
|
 #include <linux/fwnode_mdio.h>
|
 #include <linux/linkmode.h>
|
 #include <linux/lsm_audit.h>
|
 #include <linux/mdio-bitbang.h>
|
 #include <linux/mdio.h>
|
 #include <linux/mdio-mux.h>
|
 #include <linux/mii.h>
|
 #include <linux/mii_timestamper.h>
|
 #include <linux/mlx5/accel.h>
|
 #include <linux/mlx5/cq.h>
|
 #include <linux/mlx5/device.h>
|
 #include <linux/mlx5/driver.h>
|
 #include <linux/mlx5/eswitch.h>
|
 #include <linux/mlx5/fs.h>
|
 #include <linux/mlx5/port.h>
|
 #include <linux/mlx5/qp.h>
|
 #include <linux/mlx5/rsc_dump.h>
|
 #include <linux/mlx5/transobj.h>
|
 #include <linux/mlx5/vport.h>
|
 #include <linux/of_mdio.h>
|
 #include <linux/of_net.h>
|
 #include <linux/pcs-lynx.h>
|
 #include <linux/pcs/pcs-xpcs.h>
|
 #include <linux/phy.h>
|
 #include <linux/phy_led_triggers.h>
|
 #include <linux/phylink.h>
|
 #include <linux/platform_data/bcmgenet.h>
|
 #include <linux/platform_data/xilinx-ll-temac.h>
|
 #include <linux/pxa168_eth.h>
|
 #include <linux/qed/qed_eth_if.h>
|
 #include <linux/qed/qed_fcoe_if.h>
|
 #include <linux/qed/qed_if.h>
|
 #include <linux/qed/qed_iov_if.h>
|
 #include <linux/qed/qed_iscsi_if.h>
|
 #include <linux/qed/qed_ll2_if.h>
|
 #include <linux/qed/qed_nvmetcp_if.h>
|
 #include <linux/qed/qed_rdma_if.h>
|
 #include <linux/sfp.h>
|
 #include <linux/sh_eth.h>
|
 #include <linux/smsc911x.h>
|
 #include <linux/soc/nxp/lpc32xx-misc.h>
|
 #include <linux/stmmac.h>
|
 #include <linux/sunrpc/svc_rdma.h>
|
 #include <linux/sxgbe_platform.h>
|
 #include <net/cfg80211.h>
|
 #include <net/dsa.h>
|
 #include <net/mac80211.h>
|
 #include <net/selftests.h>
|
 #include <rdma/ib_addr.h>
|
 #include <rdma/ib_cache.h>
|
 #include <rdma/ib_cm.h>
|
 #include <rdma/ib_hdrs.h>
|
 #include <rdma/ib_mad.h>
|
 #include <rdma/ib_marshall.h>
|
 #include <rdma/ib_pack.h>
|
 #include <rdma/ib_pma.h>
|
 #include <rdma/ib_sa.h>
|
 #include <rdma/ib_smi.h>
|
 #include <rdma/ib_umem.h>
|
 #include <rdma/ib_umem_odp.h>
|
 #include <rdma/ib_verbs.h>
|
 #include <rdma/iw_cm.h>
|
 #include <rdma/mr_pool.h>
|
 #include <rdma/opa_addr.h>
|
 #include <rdma/opa_port_info.h>
|
 #include <rdma/opa_smi.h>
|
 #include <rdma/opa_vnic.h>
|
 #include <rdma/rdma_cm.h>
|
 #include <rdma/rdma_cm_ib.h>
|
 #include <rdma/rdmavt_cq.h>
|
 #include <rdma/rdma_vt.h>
|
 #include <rdma/rdmavt_qp.h>
|
 #include <rdma/rw.h>
|
 #include <rdma/tid_rdma_defs.h>
|
 #include <rdma/uverbs_ioctl.h>
|
 #include <rdma/uverbs_named_ioctl.h>
|
 #include <rdma/uverbs_std_types.h>
|
 #include <rdma/uverbs_types.h>
|
 #include <soc/mscc/ocelot.h>
|
 #include <soc/mscc/ocelot_ptp.h>
|
 #include <soc/mscc/ocelot_vcap.h>
|
 #include <trace/events/ib_mad.h>
|
 #include <trace/events/rdma_core.h>
|
 #include <trace/events/rdma.h>
|
 #include <trace/events/rpcrdma.h>
|
 #include <uapi/linux/ethtool.h>
|
 #include <uapi/linux/ethtool_netlink.h>
|
 #include <uapi/linux/mdio.h>
|
 #include <uapi/linux/mii.h>
)

@depends on i@
expression list args;
@@

(
- bitmap_zero(args, __ETHTOOL_LINK_MODE_MASK_NBITS)
+ linkmode_zero(args)
|
- bitmap_copy(args, __ETHTOOL_LINK_MODE_MASK_NBITS)
+ linkmode_copy(args)
|
- bitmap_and(args, __ETHTOOL_LINK_MODE_MASK_NBITS)
+ linkmode_and(args)
|
- bitmap_or(args, __ETHTOOL_LINK_MODE_MASK_NBITS)
+ linkmode_or(args)
|
- bitmap_empty(args, ETHTOOL_LINK_MODE_MASK_NBITS)
+ linkmode_empty(args)
|
- bitmap_andnot(args, __ETHTOOL_LINK_MODE_MASK_NBITS)
+ linkmode_andnot(args)
|
- bitmap_equal(args, __ETHTOOL_LINK_MODE_MASK_NBITS)
+ linkmode_equal(args)
|
- bitmap_intersects(args, __ETHTOOL_LINK_MODE_MASK_NBITS)
+ linkmode_intersects(args)
|
- bitmap_subset(args, __ETHTOOL_LINK_MODE_MASK_NBITS)
+ linkmode_subset(args)
)

Add missing linux/mii.h include to mellanox. -DaveM
Signed-off-by: NSean Anderson <sean.anderson@seco.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The magic number 4 in VLAN table lookup was the number of entries we
can read and write at once.  Using phy_port_cnt here doesn't make
sense and presumably broke VLAN filtering for 3-port switches.  Change
it back to 4.

Fixes: 4ce2a984 ("net: dsa: microchip: ksz8795: use phy_port_cnt ...")
Signed-off-by: NBen Hutchings <ben.hutchings@mind.be>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently ksz8_port_vlan_filtering() sets or clears the VLAN Enable
hardware flag.  That controls discarding of packets with a VID that
has not been enabled for any port on the switch.

Since it is a global flag, set the dsa_switch::vlan_filtering_is_global
flag so that the DSA core understands this can't be controlled per
port.

When VLAN filtering is enabled, the switch should also discard packets
with a VID that's not enabled on the ingress port.  Set or clear each
external port's VLAN Ingress Filter flag in ksz8_port_vlan_filtering()
to make that happen.

Fixes: e66f840c ("net: dsa: ksz: Add Microchip KSZ8795 DSA driver")
Signed-off-by: NBen Hutchings <ben.hutchings@mind.be>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

On the CPU port, we can support both tagged and untagged VLANs at the
same time by doing any necessary untagging in software rather than
hardware.  To enable that, keep the CPU port's Remove Tag flag cleared
and set the dsa_switch::untag_bridge_pvid flag.

Fixes: e66f840c ("net: dsa: ksz: Add Microchip KSZ8795 DSA driver")
Signed-off-by: NBen Hutchings <ben.hutchings@mind.be>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a VLAN is deleted from a port, the flags in struct
switchdev_obj_port_vlan are always 0.  ksz8_port_vlan_del() copies the
BRIDGE_VLAN_INFO_UNTAGGED flag to the port's Tag Removal flag, and
therefore always clears it.

In case there are multiple VLANs configured as untagged on this port -
which seems useless, but is allowed - deleting one of them changes the
remaining VLANs to be tagged.

It's only ever necessary to change this flag when a VLAN is added to
the port, so leave it unchanged in ksz8_port_vlan_del().

Fixes: e66f840c ("net: dsa: ksz: Add Microchip KSZ8795 DSA driver")
Signed-off-by: NBen Hutchings <ben.hutchings@mind.be>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The switches supported by ksz8795 only have a per-port flag for Tag
Removal.  This means it is not possible to support both tagged and
untagged VLANs on the same port.  Reject attempts to add a VLAN that
requires the flag to be changed, unless there are no VLANs currently
configured.

VID 0 is excluded from this check since it is untagged regardless of
the state of the flag.

On the CPU port we could support tagged and untagged VLANs at the same
time.  This will be enabled by a later patch.

Fixes: e66f840c ("net: dsa: ksz: Add Microchip KSZ8795 DSA driver")
Signed-off-by: NBen Hutchings <ben.hutchings@mind.be>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ksz8795 has never actually enabled PVID tag insertion, and it also
programmed the PVID incorrectly.  To fix this:

* Allow tag insertion to be controlled per ingress port.  On most
  chips, set bit 2 in Global Control 19.  On KSZ88x3 this control
  flag doesn't exist.

* When adding a PVID:
  - Set the appropriate register bits to enable tag insertion on
    egress at every other port if this was the packet's ingress port.
  - Mask *out* the VID from the default tag, before or-ing in the new
    PVID.

* When removing a PVID:
  - Clear the same control bits to disable tag insertion.
  - Don't update the default tag.  This wasn't doing anything useful.

Fixes: e66f840c ("net: dsa: ksz: Add Microchip KSZ8795 DSA driver")
Signed-off-by: NBen Hutchings <ben.hutchings@mind.be>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch support for cable test for the ksz886x switches and the
ksz8081 PHY.

The patch was tested on a KSZ8873RLL switch with following results:

- port 1:
  - provides invalid values, thus return -ENOTSUPP
    (Errata: DS80000830A: "LinkMD does not work on Port 1",
     http://ww1.microchip.com/downloads/en/DeviceDoc/KSZ8873-Errata-DS80000830A.pdf)

- port 2:
  - can detect distance
  - can detect open on each wire of pair A (wire 1 and 2)
  - can detect open only on one wire of pair B (only wire 3)
  - can detect short between wires of a pair (wires 1 + 2 or 3 + 6)
  - short between pairs is detected as open.
    For example short between wires 2 + 3 is detected as open.
Signed-off-by: NOleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add mapping for LINK_MD register to enable cable testing functionality.
Signed-off-by: NOleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add support for MDI-X status and configuration
Signed-off-by: NOleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>