moxart_ether: pass struct device to DMA API functions

The DMA API generally relies on a struct device to work properly, and
only barely works without one for legacy reasons. Pass the easily
available struct device from the platform_device to remedy this.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: moxa: Add spaces preferred around that '{+,-}'

This patch fixes all checkpatch occurences of
"CHECK: spaces preferred around that '{+,-}' (ctx:VxV)"
in moxart_ether code.

Signed-off-by: SZ Lin <sz.lin@moxa.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: moxa: Use net_device_stats from struct net_device

Instead of using a private copy of struct net_device_stats in struct
moxart_mac_priv_t, use stats from struct net_device. Also remove the now
unnecessary .ndo_get_stats function.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: moxa: fix TX overrun memory leak

moxart_mac_start_xmit() doesn't care where tx_tail is, tx_head can
catch and pass tx_tail, which is bad because moxart_tx_finished()
isn't guaranteed to catch up on freeing resources from tx_tail.

Add a check in moxart_mac_start_xmit() stopping the queue at the
end of the circular buffer. Also add a check in moxart_tx_finished()
waking the queue if the buffer has TX_WAKE_THRESHOLD or more
free descriptors.

While we're at it, move spin_lock_irq() to happen before our
descriptor pointer is assigned in moxart_mac_start_xmit().

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=99451

Signed-off-by: Jonas Jensen <jonas.jensen@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: moxart: use correct accessors for DMA memory

The moxart ethernet driver confuses coherent DMA buffers with
MMIO registers.

moxart_ether.c: In function 'moxart_mac_setup_desc_ring':
moxart_ether.c:146:428: error: passing argument 1 of '__fswab32' makes integer from pointer without a cast [-Werror=int-conversion]
moxart_ether.c:74:39: warning: incorrect type in argument 3 (different address spaces)
moxart_ether.c:74:39: expected void *cpu_addr
moxart_ether.c:74:39: got void [noderef] <asn:2>*tx_desc_base

This leaves the basic logic alone and uses normal pointers for
the virtual address of the descriptor. As we cannot use readl/writel
to access them, we also introduce our own moxart_desc_read
moxart_desc_write helpers that perform the same endianess swap
as the original code, but without the address space conversion.

The barriers are made explicit here where needed: Even in the worst-case
scenario, we just have to use a rmb() after checking ownership so
we don't read any input data before we are sure it is value, and we
use wmb() before transferring ownership back to the device.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Add MOXA ART SoCs ethernet driver

The MOXA UC-711X hardware(s) has an ethernet controller that seem
to be developed internally. The IC used is "RTL8201CP".

Since there is no public documentation, this driver is mostly the
one published by MOXA that has been heavily cleaned up / ported
from linux 2.6.9.

Signed-off-by: Jonas Jensen <jonas.jensen@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>