net: mvpp2: Add parsing support for different IPv4 IHL values

Add parser entries for different IPv4 IHL values.
Each entry will set the L4 header offset according to the IPv4 IHL field.
L3 header offset will set during the parsing of the IPv4 protocol.

Because of missed parser support for IP header length > 20, RX IPv4 checksum HW offload fails
and skb->ip_summed set to CHECKSUM_NONE(checksum done by Network stack).
This patch adds RX IPv4 checksum HW offload capability for frames with IP header length > 20.

v1 --> v2
- Improve commit message.

Suggested-by: Dana Vardi <danat@marvell.com>
Signed-off-by: Stefan Chulski <stefanc@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: mvpp2: add an entry to skip parser

This entry used when skipping the parser needed,
for example, the custom header pretended to ethernet header.

Suggested-by: Liron Himi <liron@marvell.com>
Signed-off-by: Stefan Chulski <stefanc@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: mvpp2: Add TCAM entry to drop flow control pause frames

Issue:
Flow control frame used to pause GoP(MAC) was delivered to the CPU
and created a load on the CPU. Since XOFF/XON frames are used only
by MAC, these frames should be dropped inside MAC.

Fix:
According to 802.3-2012 - IEEE Standard for Ethernet pause frame
has unique destination MAC address 01-80-C2-00-00-01.
Add TCAM parser entry to track and drop pause frames by destination MAC.

Fixes: 3f518509dedc ("ethernet: Add new driver for Marvell Armada 375 network unit")
Signed-off-by: Stefan Chulski <stefanc@marvell.com>
Link: https://lore.kernel.org/r/1608229817-21951-1-git-send-email-stefanc@marvell.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: mvpp2: debugfs: add hit counter stats for Header Parser entries

One helpful feature to help debug the Header Parser TCAM filter in PPv2
is to be able to see if the entries did match something when a packet
comes in. This can be done by using the built-in hit counter for TCAM
entries.

This commit implements reading the counter, and exposing its value on
debugfs for each filter entry.

The counter is a 16-bits clear-on-read value, located at:
.../mvpp2/<controller>/parser/XXX/hits

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: mvpp2: add a debugfs interface for the Header Parser

Marvell PPv2 Packer Header Parser has a TCAM based filter, that is not
trivial to configure and debug. Being able to dump TCAM entries from
userspace can be really helpful to help development of new features
and debug existing ones.

This commit adds a basic debugfs interface for the PPv2 driver, focusing
on TCAM related features.

<mnt>/mvpp2/ --- f2000000.ethernet
\- f4000000.ethernet --- parser --- 000 ...
| \- 001
| \- ...
| \- 255 --- ai
| \- header_data
| \- lookup_id
| \- sram
| \- valid
\- eth1 ...
\- eth2 --- mac_filter
\- parser_entries
\- vid_filter

There's one directory per PPv2 instance, named after pdev->name to make
sure names are uniques. In each of these directories, there's :

- one directory per interface on the controller, each containing :

- "mac_filter", which lists all filtered addresses for this port
(based on TCAM, not on the kernel's uc / mc lists)

- "parser_entries", which lists the indices of all valid TCAM
entries that have this port in their port map

- "vid_filter", which lists the vids allowed on this port, based on
TCAM

- one "parser" directory (the parser is common to all ports), containing :

- one directory per TCAM entry (256 of them, from 0 to 255), each
containing :

- "ai" : Contains the 1 byte Additional Info field from TCAM, and

- "header_data" : Contains the 8 bytes Header Data extracted from
the packet

- "lookup_id" : Contains the 4 bits LU_ID

- "sram" : contains the raw SRAM data, which is the result of the TCAM
lookup. This readonly at the moment.

- "valid" : Indicates if the entry is valid of not.

All entries are read-only, and everything is output in hex form.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: mvpp2: switch to SPDX identifiers

Use the appropriate SPDX license identifiers and drop the license text.
This patch is only cosmetic.

Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: mvpp2: split ingress traffic into multiple flows

The PPv2 classifier allows to perform classification operations on each
ingress packet, based on the flow the packet is assigned to.

The current code uses only 1 flow per port, and the only classification
action consists of assigning the rx queue to the packet, depending on the
port.

In preparation for adding RSS support, we have to split all incoming
traffic into different flows. Since RSS assigns a rx queue depending on
the hash of some header fields, we have to make sure that the hash is
generated in a consistent way for all packets in the same flow.

What we call a "flow" is actually a set of attributes attached to a
packet that depends on various L2/L3/L4 info.

This patch introduces 52 flows, wich are a combination of various L2, L3
and L4 attributes :
- Whether or not the packet has a VLAN tag
- Whether the packet is IPv4, IPv6 or something else
- Whether the packet is TCP, UDP or something else
- Whether or not the packet is fragmented at L3 level.

The flow is associated to a packet by the Header Parser. Each flow
corresponds to an entry in the decoding table. This entry then points to
the sequence of classification lookups to be performed by the
classifier, represented in the flow table.

For now, the only lookup we perform is a C2 lookup to set the default
rx queue.

Header parser Dec table
Ingress pkt +-------------+ flow id +----------------------------+
------------->| TCAM + SRAM |-------->|TCP IPv4 w/ VLAN, not frag |
+-------------+ |TCP IPv4 w/o VLAN, not frag |
|TCP IPv4 w/ VLAN, frag |--+
|etc. | |
+----------------------------+ |
|
Flow table |
+------------+ +---------------------+ |
To RxQ <---| Classifier |<-------| flow 0: C2 lookup |<--------+
+------------+ | flow 1: C2 lookup |
| | ... |
+------------+ | flow 51 : C2 lookup |
| C2 engine | +---------------------+
+------------+

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: mvpp2: fix include guards in mvpp2_prs.h

Include guards should be put before #includes. This doesn't fix any bug,
but prevent future compilation issues when adding new files in the mvpp2
driver

The Header Parser init function needs the platform_device definition,
and with the fixed include guards we need to add the missing include.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: mvpp2: prs: Drop unions representing TCAM and SRAM entries

PPv2's Header Parser use some large TCAM and SRAM entries, that are
duplicated in software so that we can write them to hardware only when
we are done modifying them.

Currently, PPv2 uses a union containing arrays of u32 and u8 to represent
these entries, to facilitate byte per byte access. This representation is
broken when we want to support big endian, and this makes the code
confusing to read.

This patch drops the union, and simply stores the TCAM and SRAM entries
as u32 arrays, each entry corresponding to a 32-bit register.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: mvpp2: Split the PPv2 driver to a dedicated directory

As the mvpp2 driver is growing, move this driver to a dedicated
directory and split it into several files.

Since this driver has a lot of register defines and structure
definitions, it can benefit from having all of this into a dedicated
header file, named mvpp2.h.

A good chunk of the mvpp2 code is dedicated to Header Parser handling, so
we introduce mvpp2_prs.h where all Header Parser definitions are located,
and mvpp2_prs.c containing the related code.

In the same way, mvpp2_cls.h and mvpp2_cls.c are created to contain
Classifier and RSS related code.

The former 'mvpp2.c' file is renamed 'mvpp2_main.c' so that we can keep
the driver binary named 'mvpp2'.

This commit is only about spliting the driver into multiple files and
doesn't introduce any new function, feature or fix besides removing
'static' keywords when needed.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Tested-by: Antoine Tenart <antoine.tenart@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>