ethernet: fix PTP_1588_CLOCK dependencies

The 'imply' keyword does not do what most people think it does, it only
politely asks Kconfig to turn on another symbol, but does not prevent
it from being disabled manually or built as a loadable module when the
user is built-in. In the ICE driver, the latter now causes a link failure:

aarch64-linux-ld: drivers/net/ethernet/intel/ice/ice_main.o: in function `ice_eth_ioctl':
ice_main.c:(.text+0x13b0): undefined reference to `ice_ptp_get_ts_config'
ice_main.c:(.text+0x13b0): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `ice_ptp_get_ts_config'
aarch64-linux-ld: ice_main.c:(.text+0x13bc): undefined reference to `ice_ptp_set_ts_config'
ice_main.c:(.text+0x13bc): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `ice_ptp_set_ts_config'
aarch64-linux-ld: drivers/net/ethernet/intel/ice/ice_main.o: in function `ice_prepare_for_reset':
ice_main.c:(.text+0x31fc): undefined reference to `ice_ptp_release'
ice_main.c:(.text+0x31fc): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `ice_ptp_release'
aarch64-linux-ld: drivers/net/ethernet/intel/ice/ice_main.o: in function `ice_rebuild':

This is a recurring problem in many drivers, and we have discussed
it several times befores, without reaching a consensus. I'm providing
a link to the previous email thread for reference, which discusses
some related problems.

To solve the dependency issue better than the 'imply' keyword, introduce a
separate Kconfig symbol "CONFIG_PTP_1588_CLOCK_OPTIONAL" that any driver
can depend on if it is able to use PTP support when available, but works
fine without it. Whenever CONFIG_PTP_1588_CLOCK=m, those drivers are
then prevented from being built-in, the same way as with a 'depends on
PTP_1588_CLOCK || !PTP_1588_CLOCK' dependency that does the same trick,
but that can be rather confusing when you first see it.

Since this should cover the dependencies correctly, the IS_REACHABLE()
hack in the header is no longer needed now, and can be turned back
into a normal IS_ENABLED() check. Any driver that gets the dependency
wrong will now cause a link time failure rather than being unable to use
PTP support when that is in a loadable module.

However, the two recently added ptp_get_vclocks_index() and
ptp_convert_timestamp() interfaces are only called from builtin code with
ethtool and socket timestamps, so keep the current behavior by stubbing
those out completely when PTP is in a loadable module. This should be
addressed properly in a follow-up.

As Richard suggested, we may want to actually turn PTP support into a
'bool' option later on, preventing it from being a loadable module
altogether, which would be one way to solve the problem with the ethtool
interface.

Fixes: 06c16d89d2cb ("ice: register 1588 PTP clock device object for E810 devices")
Link: https://lore.kernel.org/netdev/20210804121318.337276-1-arnd@kernel.org/
Link: https://lore.kernel.org/netdev/CAK8P3a06enZOf=XyZ+zcAwBczv41UuCTz+=0FMf2gBz1_cOnZQ@mail.gmail.com/
Link: https://lore.kernel.org/netdev/CAK8P3a3=eOxE-K25754+fB_-i_0BZzf9a9RfPTX3ppSwu9WZXw@mail.gmail.com/
Link: https://lore.kernel.org/netdev/20210726084540.3282344-1-arnd@kernel.org/
Acked-by: Shannon Nelson <snelson@pensando.io>
Acked-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20210812183509.1362782-1-arnd@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

ethernet: select CONFIG_CRC32 as needed

A number of ethernet drivers require crc32 functionality to be
avaialable in the kernel, causing a link error otherwise:

arm-linux-gnueabi-ld: drivers/net/ethernet/agere/et131x.o: in function `et1310_setup_device_for_multicast':
et131x.c:(.text+0x5918): undefined reference to `crc32_le'
arm-linux-gnueabi-ld: drivers/net/ethernet/cadence/macb_main.o: in function `macb_start_xmit':
macb_main.c:(.text+0x4b88): undefined reference to `crc32_le'
arm-linux-gnueabi-ld: drivers/net/ethernet/faraday/ftgmac100.o: in function `ftgmac100_set_rx_mode':
ftgmac100.c:(.text+0x2b38): undefined reference to `crc32_le'
arm-linux-gnueabi-ld: drivers/net/ethernet/freescale/fec_main.o: in function `set_multicast_list':
fec_main.c:(.text+0x6120): undefined reference to `crc32_le'
arm-linux-gnueabi-ld: drivers/net/ethernet/freescale/fman/fman_dtsec.o: in function `dtsec_add_hash_mac_address':
fman_dtsec.c:(.text+0x830): undefined reference to `crc32_le'
arm-linux-gnueabi-ld: drivers/net/ethernet/freescale/fman/fman_dtsec.o:fman_dtsec.c:(.text+0xb68): more undefined references to `crc32_le' follow
arm-linux-gnueabi-ld: drivers/net/ethernet/netronome/nfp/nfpcore/nfp_hwinfo.o: in function `nfp_hwinfo_read':
nfp_hwinfo.c:(.text+0x250): undefined reference to `crc32_be'
arm-linux-gnueabi-ld: nfp_hwinfo.c:(.text+0x288): undefined reference to `crc32_be'
arm-linux-gnueabi-ld: drivers/net/ethernet/netronome/nfp/nfpcore/nfp_resource.o: in function `nfp_resource_acquire':
nfp_resource.c:(.text+0x144): undefined reference to `crc32_be'
arm-linux-gnueabi-ld: nfp_resource.c:(.text+0x158): undefined reference to `crc32_be'
arm-linux-gnueabi-ld: drivers/net/ethernet/nxp/lpc_eth.o: in function `lpc_eth_set_multicast_list':
lpc_eth.c:(.text+0x1934): undefined reference to `crc32_le'
arm-linux-gnueabi-ld: drivers/net/ethernet/rocker/rocker_ofdpa.o: in function `ofdpa_flow_tbl_do':
rocker_ofdpa.c:(.text+0x2e08): undefined reference to `crc32_le'
arm-linux-gnueabi-ld: drivers/net/ethernet/rocker/rocker_ofdpa.o: in function `ofdpa_flow_tbl_del':
rocker_ofdpa.c:(.text+0x3074): undefined reference to `crc32_le'
arm-linux-gnueabi-ld: drivers/net/ethernet/rocker/rocker_ofdpa.o: in function `ofdpa_port_fdb':
arm-linux-gnueabi-ld: drivers/net/ethernet/mellanox/mlx5/core/steering/dr_ste.o: in function `mlx5dr_ste_calc_hash_index':
dr_ste.c:(.text+0x354): undefined reference to `crc32_le'
arm-linux-gnueabi-ld: drivers/net/ethernet/microchip/lan743x_main.o: in function `lan743x_netdev_set_multicast':
lan743x_main.c:(.text+0x5dc4): undefined reference to `crc32_le'

Add the missing 'select CRC32' entries in Kconfig for each of them.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: Madalin Bucur <madalin.bucur@oss.nxp.com>
Acked-by: Mark Einon <mark.einon@gmail.com>
Acked-by: Simon Horman <simon.horman@netronome.com>
Link: https://lore.kernel.org/r/20201203232114.1485603-1-arnd@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

treewide: replace '---help---' in Kconfig files with 'help'

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

a) 4 spaces + '---help---'
b) 7 spaces + '---help---'
c) 8 spaces + '---help---'
d) 1 space + 1 tab + '---help---'
e) 1 tab + '---help---' (correct indentation)
f) 1 tab + 1 space + '---help---'
g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

$ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

net: Make PTP-specific drivers depend on PTP_1588_CLOCK

Commit d1cbfd771ce8 ("ptp_clock: Allow for it to be optional") changed
all PTP-capable Ethernet drivers from `select PTP_1588_CLOCK` to `imply
PTP_1588_CLOCK`, "in order to break the hard dependency between the PTP
clock subsystem and ethernet drivers capable of being clock providers."
As a result it is possible to build PTP-capable Ethernet drivers without
the PTP subsystem by deselecting PTP_1588_CLOCK. Drivers are required to
handle the missing dependency gracefully.

Some PTP-capable Ethernet drivers (e.g., TI_CPSW) factor their PTP code
out into separate drivers (e.g., TI_CPTS_MOD). The above commit also
changed these PTP-specific drivers to `imply PTP_1588_CLOCK`, making it
possible to build them without the PTP subsystem. But as Grygorii
Strashko noted in [1]:

On Wed, Apr 22, 2020 at 02:16:11PM +0300, Grygorii Strashko wrote:

> Another question is that CPTS completely nonfunctional in this case and
> it was never expected that somebody will even try to use/run such
> configuration (except for random build purposes).

In my view, enabling a PTP-specific driver without the PTP subsystem is
a configuration error made possible by the above commit. Kconfig should
not allow users to create a configuration with missing dependencies that
results in "completely nonfunctional" drivers.

I audited all network drivers that call ptp_clock_register() but merely
`imply PTP_1588_CLOCK` and found five PTP-specific drivers that are
likely nonfunctional without PTP_1588_CLOCK:

NET_DSA_MV88E6XXX_PTP
NET_DSA_SJA1105_PTP
MACB_USE_HWSTAMP
CAVIUM_PTP
TI_CPTS_MOD

Note how these symbols all reference PTP or timestamping in their name;
this is a clue that they depend on PTP_1588_CLOCK.

Change them from `imply PTP_1588_CLOCK` [2] to `depends on PTP_1588_CLOCK`.
I'm not using `select PTP_1588_CLOCK` here because PTP_1588_CLOCK has
its own dependencies, which `select` would not transitively apply.

Additionally, remove the `select NET_PTP_CLASSIFY` from CPTS_TI_MOD;
PTP_1588_CLOCK already selects that.

[1]: https://lore.kernel.org/lkml/c04458ed-29ee-1797-3a11-7f3f560553e6@ti.com/

[2]: NET_DSA_SJA1105_PTP had never declared any type of dependency on
PTP_1588_CLOCK (`imply` or otherwise); adding a `depends on PTP_1588_CLOCK`
here seems appropriate.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Fixes: d1cbfd771ce8 ("ptp_clock: Allow for it to be optional")
Signed-off-by: Clay McClure <clay@daemons.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: macb: convert to phylink

This patch converts the MACB Ethernet driver to the Phylink framework.
The MAC configuration is moved to the Phylink ops and Phylink helpers
are now used in the ethtools functions. This helps to access the flow
control and pauseparam logic and this will be helpful in the future for
boards using this controller with SFP cages.

Tested-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: macb: Kconfig: Rename Atmel to Cadence

The help text makes it look like NET_VENDOR_CADENCE enables support for
Atmel devices, when in reality it's a driver written by Atmel that
supports Cadence devices. This may confuse users that have this device
on a non-Atmel SoC.

The fix is just s/Atmel/Cadence/, but I did go and re-wrap the Kconfig
help text as that change caused it to go over 80 characters.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: macb: Kconfig: Make MACB depend on COMMON_CLK

commit c218ad559020 ("macb: Add support for SiFive FU540-C000") added a
dependency on the common clock framework to the macb driver, but didn't
express that dependency in Kconfig. As a result macb now fails to
compile on systems without COMMON_CLK, which specifically causes a build
failure on powerpc allyesconfig.

This patch adds the dependency, which results in the macb driver no
longer being selectable on systems without the common clock framework.
All known systems that have this device already support the common clock
framework, so this should not cause trouble for any uses. Supporting
both the FU540-C000 and systems without COMMON_CLK is quite ugly.

I've build tested this on powerpc allyesconfig and RISC-V defconfig
(which selects MACB), but I have not even booted the resulting kernels.

Fixes: c218ad559020 ("macb: Add support for SiFive FU540-C000")
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net: ethernet: Add missing VENDOR to Cadence and Packet Engines symbols

The vendor guard Kconfig symbols for Cadence and Packet Engines use a
"NET_" prefix, while all other vendor guards use a "NET_VENDOR_"
prefix. Hence make them consistent with the rest, and add the missing
trailing "S" for Packet Engines while at it.

As these options don't directly affect the kernel build, and default to
"y", this change has no impact on kernels built with existing
(def)configs.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: macb: Add support for PTP timestamps in DMA descriptors

This patch adds support for PTP timestamps in
DMA buffer descriptors. It checks capability at runtime
and uses appropriate buffer descriptor.

Signed-off-by: Rafal Ozieblo <rafalo@cadence.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: macb: Added PCI wrapper for Platform Driver.

There are hardware PCI implementations of Cadence GEM network
controller. This patch will allow to use such hardware with reuse of
existing Platform Driver.

Signed-off-by: Bartosz Folta <bfolta@cadence.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net: remove all references to obsolete Ethernet-HOWTO

This howto made sense in the 1990s when users had to manually configure
ISA cards with jumpers or vendor utilities, but with the implementation
of PCI it became increasingly less and less relevant, to the point where
it has been well over a decade since I last updated it. And there is
no value in anyone else taking over updating it either.

However the references to it continue to spread as boiler plate text
from one Kconfig file into the next. We are not doing end users any
favours by pointing them at this old document, so lets kill it with
fire, once and for all, to hopefully stop any further spread.

No code is changed in this commit, just Kconfig help text.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/macb: merge at91_ether driver into macb driver

macb and at91_ether drivers can be compiled as modules, but the at91_ether
driver use some functions and variables defined in the macb one, thus
creating a dependency on the macb driver.

Since these drivers are sharing the same logic we can easily merge
at91_ether into macb.

In order to factorize common probing logic we've added an ->init() function
to struct macb_config (the structure associated with the compatible
string), and moved macb specific init code from macb_probe to macb_init.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: cadence: Remove Kconfig dependency on ARCH

Remove Kconfig dependency and enable driver for
all ARCHs.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Sören Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: macb: Remove obsolete comment from Kconfig

The Kconfig file says that Gigabit mode is not supported, but it has been
supported since commit 140b7552fdff04bbceeb842f0e04f0b4015fe97b ("net/macb:
Add support for Gigabit Ethernet mode").

Signed-off-by: James Byrne <james.byrne@origamienergy.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ARM: at91/Kconfig: remove ARCH_AT91RM9200 option for drivers

The precise selection is useless, so we simply remove these dependencies.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Boris BREZILLON <boris.brezillon@free-electrons.com>

net: cadence: Fix architecture dependencies

I was told that the Cadence macb driver is also useful on Microblaze.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mark Brown <broonie@kernel.org>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: cadence: Add architecture dependencies

The Cadence ethernet chipsets are only used on specific ARM
architectures. Add Kconfig dependencies so that drivers for these
chipsets are only buildable on the relevant architectures.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove GENERIC_HARDIRQ config option

After the last architecture switched to generic hard irqs the config
options HAVE_GENERIC_HARDIRQS & GENERIC_HARDIRQS and the related code
for !CONFIG_GENERIC_HARDIRQS can be removed.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

at91_ether: Do not select NET_CORE

This has no dependency on any of the drivers under NET_CORE.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ethernet: MACB should depend on HAS_DMA

If NO_DMA=y:

drivers/built-in.o: In function `macb_free_consistent':
drivers/net/ethernet/cadence/macb.c:878: undefined reference to `dma_free_coherent'
drivers/net/ethernet/cadence/macb.c:883: undefined reference to `dma_free_coherent'
drivers/net/ethernet/cadence/macb.c:888: undefined reference to `dma_free_coherent'
drivers/built-in.o: In function `macb_alloc_consistent':
drivers/net/ethernet/cadence/macb.c:905: undefined reference to `dma_alloc_coherent'
drivers/built-in.o: In function `macb_tx_interrupt':
drivers/net/ethernet/cadence/macb.c:515: undefined reference to `dma_unmap_single'
drivers/built-in.o: In function `macb_tx_error_task':
drivers/net/ethernet/cadence/macb.c:457: undefined reference to `dma_unmap_single'
drivers/built-in.o: In function `macb_start_xmit':
drivers/net/ethernet/cadence/macb.c:838: undefined reference to `dma_map_single'

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ethernet: ARM_AT91_ETHER should depend on HAS_DMA

If NO_DMA=y:

drivers/built-in.o: In function `at91ether_start':
drivers/net/ethernet/cadence/at91_ether.c:49: undefined reference to `dma_alloc_coherent'
drivers/net/ethernet/cadence/at91_ether.c:60: undefined reference to `dma_free_coherent'
drivers/built-in.o: In function `at91ether_interrupt':
drivers/net/ethernet/cadence/at91_ether.c:250: undefined reference to `dma_unmap_single'
drivers/built-in.o: In function `at91ether_start_xmit':
drivers/net/ethernet/cadence/at91_ether.c:169: undefined reference to `dma_map_single'
drivers/built-in.o: In function `at91ether_close':
drivers/net/ethernet/cadence/at91_ether.c:145: undefined reference to `dma_free_coherent'

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net,AT91RM9200: add missing GENERIC_HARDIRQS dependency

The AT91RM9200 driver call devm_request_irq() and therefore should
depend on GENERIC_HARDIRQS to prevent link/compile errors on plaforms
without GENERIC_HARDIRQS.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

net/cadence: depend on HAS_IOMEM

Fixes the following build failure on S390:
In file included from drivers/net/ethernet/cadence/at91_ether.c:35:0:
drivers/net/ethernet/cadence/macb.h: In function 'macb_is_gem':
drivers/net/ethernet/cadence/macb.h:563:2: error: implicit declaration of function '__raw_readl' [-Werror=implicit-function-declaration]
drivers/net/ethernet/cadence/at91_ether.c: In function 'update_mac_address':
drivers/net/ethernet/cadence/at91_ether.c:119:2: error: implicit declaration of function '__raw_writel' [-Werror=implicit-function-declaration]
cc1: some warnings being treated as errors

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Joachim Eastwood <manabian@gmail.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/at91_ether: add pdata flag for reverse Eth addr

This will allow us to remove the last mach include from at91_ether
and also make it easier to share address setup with macb.

Signed-off-by: Joachim Eastwood <manabian@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/at91_ether: select MACB in Kconfig

Now that HAVE_NET_MACB is gone let's just select MACB to
satisfy the dependecies in at91_ether.

Signed-off-by: Joachim Eastwood <manabian@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/cadence: get rid of HAVE_NET_MACB

macb is a platform driver and there is nothing that prevents
this driver from being built on non-ARM/AVR32 platforms.

Signed-off-by: Joachim Eastwood <manabian@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/at91_ether: compile macb for exported functions

Comile macb as well as at91_ether to access exported functions.

Signed-off-by: Joachim Eastwood <manabian@gmail.com>

macb: initial support for Cadence GEM

The Cadence GEM is based on the MACB Ethernet controller but has a few
small changes with regards to register and bitfield placement. This
patch detects the presence of a GEM by reading the module ID register
and setting a flag appropriately.

This handles the new HW address, USRIO and hash register base register
locations in GEM.

v3: - convert to macb_is_gem() inline rather than storing a boolean
flag
- handle rx_overrun stats for gem

Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Tested-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

net/cadence: enable by default NET_ATMEL

so the defconfig of the atmel continue to have the support of the network
as before

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

MII: fix Kconfig dependencies for MII

MII Kconfig option is apart of the core networking drivers and
by default NET_CORE is enabled so drivers selecting MII will
have MII enabled as well. It was found using the randconfig
option during testing, MII would be selected but NET_CORE
could be disabled. This caused a dependency error.

Resolved the dependency by selecting NET_CORE when MII is
selected.

Reported-by: Emil Tantilov <emil.s.tantilov@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

macb: Move the Atmel driver

Move the Atmel driver into drivers/net/ethernet/cadence/ and
make the necessary Kconfig and Makefile changes.

CC: Nicolas Ferre <nicolas.ferre@atmel.com>
CC: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>