Buffer manager (BM) is a dedicated hardware unit that can be used by all
ethernet ports of Armada XP and 38x SoC's. It allows to offload CPU on RX
path by sparing DRAM access on refilling buffer pool, hardware-based
filling of descriptor ring data and better memory utilization due to HW
arbitration for using 'short' pools for small packets.

Tests performed with A388 SoC working as a network bridge between two
packet generators showed increase of maximum processed 64B packets by
~20k (~555k packets with BM enabled vs ~535 packets without BM). Also
when pushing 1500B-packets with a line rate achieved, CPU load decreased
from around 25% without BM to 20% with BM.

BM comprise up to 4 buffer pointers' (BP) rings kept in DRAM, which
are called external BP pools - BPPE. Allocating and releasing buffer
pointers (BP) to/from BPPE is performed indirectly by write/read access
to a dedicated internal SRAM, where internal BP pools (BPPI) are placed.
BM hardware controls status of BPPE automatically, as well as assigning
proper buffers to RX descriptors. For more details please refer to
Functional Specification of Armada XP or 38x SoC.

In order to enable support for a separate hardware block, common for all
ports, a new driver has to be implemented ('mvneta_bm'). It provides
initialization sequence of address space, clocks, registers, SRAM,
empty pools' structures and also obtaining optional configuration
from DT (please refer to device tree binding documentation). mvneta_bm
exposes also a necessary API to mvneta driver, as well as a dedicated
structure with BM information (bm_priv), whose presence is used as a
flag notifying of BM usage by port. It has to be ensured that mvneta_bm
probe is executed prior to the ones in ports' driver. In case BM is not
used or its probe fails, mvneta falls back to use software buffer
management.

A sequence executed in mvneta_probe function is modified in order to have
an access to needed resources before possible port's BM initialization is
done. According to port-pools mapping provided by DT appropriate registers
are configured and the buffer pools are filled. RX path is modified
accordingly. Becaues the hardware allows a wide variety of configuration
options, following assumptions are made:
* using BM mechanisms can be selectively disabled/enabled basing
  on DT configuration among the ports
* 'long' pool's single buffer size is tied to port's MTU
* using 'long' pool by port is obligatory and it cannot be shared
* using 'short' pool for smaller packets is optional
* one 'short' pool can be shared among all ports

This commit enables hardware buffer management operation cooperating with
existing mvneta driver. New device tree binding documentation is added and
the one of mvneta is updated accordingly.

[gregory.clement@free-electrons.com: removed the suspend/resume part]
Signed-off-by: NMarcin Wojtas <mw@semihalf.com>
Signed-off-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJisheng Zhang <jszhang@marvell.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since Armada 38x SoC can support IP checksum for jumbo frames only on
a single port, it means that this feature should be enabled per-port,
rather than for the whole SoC.

This patch enables setting custom TX IP checksum limit by adding new
optional property to the mvneta device tree node. If not used, by
default 1600B is set for "marvell,armada-370-neta" and 9800B for other
strings, which ensures backward compatibility. Binding documentation
is updated accordingly.
Signed-off-by: NMarcin Wojtas <mw@semihalf.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The mvneta driver supports the Ethernet IP found in the Armada 370, XP,
380 and 385 SoCs. Since at least one more hardware feature is available
for the Armada XP SoCs then a way to identify them is needed.

This patch introduces a new compatible string "marvell,armada-xp-neta".
Signed-off-by: NSimon Guinot <simon.guinot@sequanux.org>
Fixes: c5aff182 ("net: mvneta: driver for Marvell Armada 370/XP network unit")
Cc: <stable@vger.kernel.org> # v3.8+
Acked-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Acked-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is an attempt to gather the Ethernet related bindings in one file,
like it's done in the MMC and some other subsystems. It should save some of
the trouble of documenting several properties over and over in each binding
document, instead only making reference to the main file.

I have used the Embedded Power Architecture(TM) Platform Requirements (ePAPR)
standard as a base for the properties description, also documenting some ad-hoc
properties that have been introduced over time despite having direct analogs in
ePAPR.
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that the Armada 370/XP platform has gained proper integration with
the clock framework, we add clk support in the Marvell Armada 370/XP
Ethernet driver.

Since the existing Device Tree binding that exposes a
'clock-frequency' property has never been exposed in any stable kernel
release, we take the freedom of removing this property to replace it
with the standard 'clocks' clock pointer property.

The Device Tree binding documentation is updated accordingly.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>

This patch contains a new network driver for the network unit of the
ARM Marvell Armada 370 and the Armada XP. Both SoCs use the PJ4B
processor, a Marvell-developed ARM core that implements the ARMv7
instruction set.

Compared to previous ARM Marvell SoCs (Kirkwood, Orion, Discovery),
the network unit in Armada 370 and Armada XP is highly different. This
is the reason why this new 'mvneta' driver is needed, while the older
ARM Marvell SoCs use the 'mv643xx_eth' driver.

Here is an overview of the most important hardware changes that
require a new, specific, driver for the network unit of Armada 370/XP:

 - The new network unit has a completely different design and layout
   for the RX and TX descriptors. They are now organized as a simple
   array (each RX and TX queue has base address and size of this
   array) rather than a linked list as in the old SoCs.

 - The new network unit has a different RXQ and TXQ management: this
   management is done using special read/write counter registers,
   while in the Old SocS, it was done using the Ownership bit in RX
   and TX descriptors.

 - The new network unit has different interrupt registers

 - The new network unit way of cleaning of interrupts is not done by
   writing to the cause register, but by updating per-queue counters

 - The new network unit has different GMAC registers (link, speed,
   duplex configuration) and different WRR registers.

 - The new network unit has lots of new units like PnC (Parser and
   Classifier), PMT, BM (Memory Buffer Management), xPON, and more.

The driver proposed in the current patch only handles the basic
features. Additional hardware features will progressively be supported
as needed.

This code has originally been written by Rami Rosen
<rosenr@marvell.com>, and then reviewed and cleaned up by Thomas
Petazzoni <thomas.petazzoni@free-electrons.com>.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>