Convert the Marvell mvneta ethernet driver to use the finalised link
parameters in mac_link_up() rather than the parameters in mac_config().
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Propagate the resolved link parameters via the mac_link_up() call for
MACs that do not automatically track their PCS state. We propagate the
link parameters via function arguments so that inappropriate members
of struct phylink_link_state can't be accessed, and creating a new
structure just for this adds needless complexity to the API.
Tested-by: NAndre Przywara <andre.przywara@arm.com>
Tested-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Tested-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Functions starting with __ usually indicate those which are exported,
but should not be called directly. Update some of those declared in the
API and make it more readable.

page_pool_unmap_page() and page_pool_release_page() were doing
exactly the same thing calling __page_pool_clean_page().  Let's
rename __page_pool_clean_page() to page_pool_release_page() and
export it in order to show up on perf logs and get rid of
page_pool_unmap_page().

Finally rename __page_pool_put_page() to page_pool_put_page() since we
can now directly call it from drivers and rename the existing
page_pool_put_page() to page_pool_put_full_page() since they do the same
thing but the latter is trying to sync the full DMA area.

This patch also updates netsec, mvneta and stmmac drivers which use
those functions.
Suggested-by: NJonathan Lemon <jonathan.lemon@gmail.com>
Acked-by: NToke Høiland-Jørgensen <toke@redhat.com>
Acked-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NIlias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce "rx" prefix in the name scheme for xdp counters
on rx path.
Differentiate between XDP_TX and ndo_xdp_xmit counters
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Acked-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Get rid of xdp_ret in mvneta_swbm_rx_frame routine since now
we can rely on xdp_stats to flush in case of xdp_redirect
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add xdp_redirect, xdp_pass, xdp_drop and xdp_tx counters
to ethtool statistics
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce mvneta_stats structure in mvneta_update_stats routine signature
in order to collect all the rx stats and update them at the end at the
napi loop. mvneta_stats will be reused adding xdp statistics support to
ethtool.
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In oreder to avoid unnecessary instructions rely on open-coding updating
per-cpu stats in mvneta_tx/mvneta_xdp_submit_frame and mvneta_rx_hwbm
routines. This patch will be used to add xdp support to ethtool for the
mvneta driver
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

mvneta_ethtool_update_stats routine is currently reporting
skb_alloc_error and refill_error only for the first rx queue.
Fix the issue moving skb_alloc_err and refill_err in
mvneta_pcpu_stats structure.
Moreover this patch will be used to introduce xdp statistics
to ethtool for the mvneta driver

Fixes: 17a96da6 ("net: mvneta: discriminate error cause for missed packet")
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move rx_dropped and rx_errors counters in mvneta_pcpu_stats in order to
avoid possible races updating statistics

Fixes: 562e2f46 ("net: mvneta: Improve the buffer allocation method for SWBM")
Fixes: dc35a10f ("net: mvneta: bm: add support for hardware buffer management")
Fixes: c5aff182 ("net: mvneta: driver for Marvell Armada 370/XP network unit")
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to fix XDP support if sw buffer management is used as fallback
for hw bm devices, define MVNETA_SKB_HEADROOM as maximum between
XDP_PACKET_HEADROOM and NET_SKB_PAD and let the hw aligns the IP header
to 4-byte boundary.
Fix rx_offset_correction initialization if mvneta_bm_port_init fails in
mvneta_resume routine

Fixes: 0db51da7 ("net: mvneta: add basic XDP support")
Tested-by: NSven Auhagen <sven.auhagen@voleatech.de>
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Recently XDP Support was added to the mvneta driver
for software buffer management only.
It is still possible to attach an XDP program if
hardware buffer management is used.
It is not doing anything at that point.

The patch disallows attaching XDP programs to mvneta
if hardware buffer management is used.

I am sorry about that. It is my first submission and I am having
some troubles with the format of my emails.

v4 -> v5:
- Remove extra tabs

v3 -> v4:
- Please ignore v3 I accidentally submitted
  my other patch with git-send-mail and v4 is correct

v2 -> v3:
- My mailserver corrupted the patch
  resubmission with git-send-email

v1 -> v2:
- Fixing the patches indentation
Signed-off-by: NSven Auhagen <sven.auhagen@voleatech.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Page pool API will start syncing (if requested) starting from
page->dma_addr + pool->p.offset. Fix dma sync length in
mvneta_run_xdp since we do not need to account xdp headroom

Fixes: 07e13edb ("net: mvneta: get rid of huge dma sync in mvneta_rx_refill")
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Acked-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With 'commit 44768dec ("page_pool: handle page recycle for NUMA_NO_NODE
condition")' we can safely change nid to NUMA_NO_NODE and accommodate
future NUMA aware hardware using mvneta network interface
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Acked-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Rename the mac_link_state() method to mac_pcs_get_state() to make it
clear that it should be returning the MACs PCS current state, which
is used for inband negotiation rather than just reading back what the
MAC has been configured for. Update the documentation to explicitly
mention that this is for inband.

We drop the return value as well; most of phylink doesn't check the
return value and it is not clear what it should do on error - instead
arrange for state->link to be false.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

Get rid of costly dma_sync_single_for_device in mvneta_rx_refill
since now the driver can let page_pool API to manage needed DMA
sync with a proper size.

- XDP_DROP DMA sync managed by mvneta driver:	~420Kpps
- XDP_DROP DMA sync managed by page_pool API:	~585Kpps
Tested-by: NMatteo Croce <mcroce@redhat.com>
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Acked-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rely on page_pool_recycle_direct and not on xdp_return_buff in
mvneta_run_xdp. This is a preliminary patch to limit the dma sync len
to the one strictly necessary
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Acked-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix build_skb for bm capable devices when they fall-back using swbm path
(e.g. when bm properties are configured in device tree but
CONFIG_MVNETA_BM_ENABLE is not set). In this case rx_offset_correction is
overwritten so we need to use it building skb instead of
MVNETA_SKB_HEADROOM directly

Fixes: 8dc9a088 ("net: mvneta: rely on build_skb in mvneta_rx_swbm poll routine")
Fixes: 0db51da7 ("net: mvneta: add basic XDP support")
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Reported-by: NAndrew Lunn <andrew@lunn.ch>
Tested-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Before this change of_get_phy_mode() returned an enum,
phy_interface_t. On error, -ENODEV etc, is returned. If the result of
the function is stored in a variable of type phy_interface_t, and the
compiler has decided to represent this as an unsigned int, comparision
with -ENODEV etc, is a signed vs unsigned comparision.

Fix this problem by changing the API. Make the function return an
error, or 0 on success, and pass a pointer, of type phy_interface_t,
where the phy mode should be stored.

v2:
Return with *interface set to PHY_INTERFACE_MODE_NA on error.
Add error checks to all users of of_get_phy_mode()
Fixup a few reverse christmas tree errors
Fixup a few slightly malformed reverse christmas trees

v3:
Fix 0-day reported errors.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement XDP_TX verdict and ndo_xdp_xmit net_device_ops function
pointer
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allow tx buffer array to contain both skb and xdp buffers in order to
enable xdp frame recycling adding XDP_TX verdict support
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move data buffer prefetch in mvneta_swbm_rx_frame after
dma_sync_single_range_for_cpu
Signed-off-by: NIlias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add basic XDP support to mvneta driver for devices that rely on software
buffer management. Currently supported verdicts are:
- XDP_DROP
- XDP_PASS
- XDP_REDIRECT
- XDP_ABORTED

- iptables drop:
$iptables -t raw -I PREROUTING -p udp --dport 9 -j DROP
$nstat -n && sleep 1 && nstat
IpInReceives		151169		0.0
IpExtInOctets		6953544		0.0
IpExtInNoECTPkts	151165		0.0

- XDP_DROP via xdp1
$./samples/bpf/xdp1 3
proto 0:	421419 pkt/s
proto 0:	421444 pkt/s
proto 0:	421393 pkt/s
proto 0:	421440 pkt/s
proto 0:	421184 pkt/s
Tested-by: NMatteo Croce <mcroce@redhat.com>
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Refactor mvneta_rx_swbm code introducing mvneta_swbm_rx_frame and
mvneta_swbm_add_rx_fragment routines. Rely on build_skb in oreder to
allocate skb since the previous patch introduced buffer recycling using
the page_pool API.
This patch fixes even an issue in the original driver where dma buffers
are accessed before dma sync.
mvneta driver can run on not cache coherent devices so it is
necessary to sync DMA buffers before sending them to the device
in order to avoid memory corruptions. Running perf analysis we can
see a performance cost associated with this DMA-sync (anyway it is
already there in the original driver code). In follow up patches we
will add more logic to reduce DMA-sync as much as possible.
Signed-off-by: NIlias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use the page_pool api for allocations and DMA handling instead of
__dev_alloc_page()/dma_map_page() and free_page()/dma_unmap_page().
Pages are unmapped using page_pool_release_page before packets
go into the network stack.

The page_pool API offers buffer recycling capabilities for XDP but
allocates one page per packet, unless the driver splits and manages
the allocated page.
This is a preliminary patch to add XDP support to mvneta driver
Signed-off-by: NIlias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce mvneta_update_stats routine to collect {rx/tx} statistics
(packets and bytes). This is a preliminary patch to add XDP support to
mvneta driver
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

devm_platform_ioremap_resource() wraps platform_get_resource() and
devm_ioremap_resource() in a single helper, let's use that helper to
simplify the code.
Signed-off-by: NJisheng Zhang <Jisheng.Zhang@synaptics.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In preparation for unifying the skb_frag and bio_vec, use the fine
accessors which already exist and use skb_frag_t instead of
struct skb_frag_struct.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Based on review, `lock' is only acquired in hwbm_pool_add() which is
invoked via ->probe(), ->resume() and ->ndo_change_mtu(). Based on this
the lock can become a mutex and there is no need to disable interrupts
during the procedure.
Now that the lock is a mutex, hwbm_pool_add() no longer invokes
hwbm_pool_refill() in an atomic context so we can pass GFP_KERNEL to
hwbm_pool_refill() and remove the `gfp' argument from hwbm_pool_add().

Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The phylink_config structure will encapsulate a pointer to a struct
device and the operation type requested for this instance of PHYLINK.
This patch does not make any functional changes, it just transitions the
PHYLINK internals and all its users to the new API.

A pointer to a phylink_config structure will be passed to
phylink_create() instead of the net_device directly. Also, the same
phylink_config pointer will be passed back to all phylink_mac_ops
callbacks instead of the net_device. Using this mechanism, a PHYLINK
user can get the original net_device using a structure such as
'to_net_dev(config->dev)' or directly the structure containing the
phylink_config using a container_of call.

At the moment, only the PHYLINK_NETDEV is defined as a valid operation
type for PHYLINK. In this mode, a valid reference to a struct device
linked to the original net_device should be passed to PHYLINK through
the phylink_config structure.

This API changes is mainly driven by the necessity of adding a new
operation type in PHYLINK that disconnects the phy_device from the
net_device and also works when the net_device is lacking.
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: NVladimir Oltean <olteanv@gmail.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: NMaxime Chevallier <maxime.chevallier@bootlin.com>
Tested-by: NMaxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix below issues in err code path of probe:
1. we don't need to unregister_netdev() because the netdev isn't
registered.
2. when register_netdev() fails, we also need to destroy bm pool for
HWBM case.

Fixes: dc35a10f ("net: mvneta: bm: add support for hardware buffer management")
Signed-off-by: NJisheng Zhang <Jisheng.Zhang@synaptics.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch fixes following (similar) warning reported by kbuild test robot:

 In function ‘memcpy’,
  inlined from ‘smsc75xx_init_mac_address’ at drivers/net/usb/smsc75xx.c:778:3,
  inlined from ‘smsc75xx_bind’ at drivers/net/usb/smsc75xx.c:1501:2:
  ./include/linux/string.h:355:9: warning: argument 2 null where non-null expected [-Wnonnull]
  return __builtin_memcpy(p, q, size);
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
  drivers/net/usb/smsc75xx.c: In function ‘smsc75xx_bind’:
  ./include/linux/string.h:355:9: note: in a call to built-in function ‘__builtin_memcpy’

I've replaced the offending memcpy with ether_addr_copy, because I'm
100% sure, that of_get_mac_address can't return NULL as it returns valid
pointer or ERR_PTR encoded value, nothing else.

I'm hesitant to just change IS_ERR into IS_ERR_OR_NULL check, as this
would make the warning disappear also, but it would be confusing to
check for impossible return value just to make a compiler happy.

I'm now changing all occurencies of memcpy to ether_addr_copy after the
of_get_mac_address call, as it's very likely, that we're going to get
similar reports from kbuild test robot in the future.

Fixes: a51645f7 ("net: ethernet: support of_get_mac_address new ERR_PTR error")
Reported-by: Nkbuild test robot <lkp@intel.com>
Signed-off-by: NPetr Štetiar <ynezz@true.cz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There was NVMEM support added to of_get_mac_address, so it could now
return ERR_PTR encoded error values, so we need to adjust all current
users of of_get_mac_address to this new fact.

While at it, remove superfluous is_valid_ether_addr as the MAC address
returned from of_get_mac_address is always valid and checked by
is_valid_ether_addr anyway.

Fixes: d01f449c ("of_net: add NVMEM support to of_get_mac_address")
Signed-off-by: NPetr Štetiar <ynezz@true.cz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It allows some of the code to be simplified.

Tested on Turris Omnia.
Signed-off-by: NRosen Penev <rosenp@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are two reasons for this.

First, the xmit_more flag conceptually doesn't fit into the skb, as
xmit_more is not a property related to the skb.
Its only a hint to the driver that the stack is about to transmit another
packet immediately.

Second, it was only done this way to not have to pass another argument
to ndo_start_xmit().

We can place xmit_more in the softnet data, next to the device recursion.
The recursion counter is already written to on each transmit. The "more"
indicator is placed right next to it.

Drivers can use the netdev_xmit_more() helper instead of skb->xmit_more
to check the "more packets coming" hint.

skb->xmit_more is retained (but always 0) to not cause build breakage.

This change takes care of the simple s/skb->xmit_more/netdev_xmit_more()/
conversions.  Remaining drivers are converted in the next patches.
Suggested-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some PHYs will use the 2500BaseX PHY_INTERFACE_MODE when being linked
with a partner using 2.5GBaseT.

Since we can't autonegotiate this speed between the MAC and the PHY, we
need to have the proper comphy support enabled, to make sure we can
safely advertise 2.5G and 1G in BaseT and be able to switch between both
corresponding PHY interface modes. This is now possible since comphy
support was added to this driver.

This commit adds the 2500BaseT mode to the list of supported modes when
using 2500BaseX, and was tested on a setup with an Armada385 and a
88E2010 PHY, both with and without the comphy node in the DT.
Signed-off-by: NMaxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The comphy driver for Armada 3700 by Miquèl Raynal (which is currently
in linux-next) does not actually set comphy mode when phy_set_mode_ext
is called. The mode is set at next call of phy_power_on.

Update the driver to semantics similar to mvpp2: helper
mvneta_comphy_init sets comphy mode and powers it on.
When mode is to be changed in mvneta_mac_config, first power the comphy
off, then call mvneta_comphy_init (which sets the mode to new one).

Only do this when new mode is different from old mode.

This should also work for Armada 38x, since in that comphy driver
methods power_on and power_off are unimplemented.
Signed-off-by: NMarek Behún <marek.behun@nic.cz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Booting 4.20 on SolidRun Clearfog issues this warning with DMA API
debug enabled:

WARNING: CPU: 0 PID: 555 at kernel/dma/debug.c:1230 check_sync+0x514/0x5bc
mvneta f1070000.ethernet: DMA-API: device driver tries to sync DMA memory it has not allocated [device address=0x000000002dd7dc00] [size=240 bytes]
Modules linked in: ahci mv88e6xxx dsa_core xhci_plat_hcd xhci_hcd devlink armada_thermal marvell_cesa des_generic ehci_orion phy_armada38x_comphy mcp3021 spi_orion evbug sfp mdio_i2c ip_tables x_tables
CPU: 0 PID: 555 Comm: bridge-network- Not tainted 4.20.0+ #291
Hardware name: Marvell Armada 380/385 (Device Tree)
[<c0019638>] (unwind_backtrace) from [<c0014888>] (show_stack+0x10/0x14)
[<c0014888>] (show_stack) from [<c07f54e0>] (dump_stack+0x9c/0xd4)
[<c07f54e0>] (dump_stack) from [<c00312bc>] (__warn+0xf8/0x124)
[<c00312bc>] (__warn) from [<c00313b0>] (warn_slowpath_fmt+0x38/0x48)
[<c00313b0>] (warn_slowpath_fmt) from [<c00b0370>] (check_sync+0x514/0x5bc)
[<c00b0370>] (check_sync) from [<c00b04f8>] (debug_dma_sync_single_range_for_cpu+0x6c/0x74)
[<c00b04f8>] (debug_dma_sync_single_range_for_cpu) from [<c051bd14>] (mvneta_poll+0x298/0xf58)
[<c051bd14>] (mvneta_poll) from [<c0656194>] (net_rx_action+0x128/0x424)
[<c0656194>] (net_rx_action) from [<c000a230>] (__do_softirq+0xf0/0x540)
[<c000a230>] (__do_softirq) from [<c00386e0>] (irq_exit+0x124/0x144)
[<c00386e0>] (irq_exit) from [<c009b5e0>] (__handle_domain_irq+0x58/0xb0)
[<c009b5e0>] (__handle_domain_irq) from [<c03a63c4>] (gic_handle_irq+0x48/0x98)
[<c03a63c4>] (gic_handle_irq) from [<c0009a10>] (__irq_svc+0x70/0x98)
...

This appears to be caused by mvneta_rx_hwbm() calling
dma_sync_single_range_for_cpu() with the wrong struct device pointer,
as the buffer manager device pointer is used to map and unmap the
buffer.  Fix this.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add support for the common phy binding, so that we can reconfigure the
comphy according to the desired ethernet speed.  This will allow us to
support 1000base-X and 2500base-X SFPs dynamically on SolidRun Clearfog.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Recent changes in the mvneta driver reworked allocation
and handling of the ingress buffers to use entire pages.
Apart from that in SW BM scenario the HW must be informed
via PRXDQS about the biggest possible incoming buffer
that can be propagated by RX descriptors.

The BufferSize field was filled according to the MTU-dependent
pkt_size value. Later change to PAGE_SIZE broke RX operation
when usin 64K pages, as the field is simply too small.

This patch conditionally limits the value passed to the BufferSize
of the PRXDQS register, depending on the PAGE_SIZE used.
On the occasion remove now unused frag_size field of the mvneta_port
structure.

Fixes: 562e2f46 ("net: mvneta: Improve the buffer allocation method for SWBM")
Signed-off-by: NMarcin Wojtas <mw@semihalf.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>