linux_dsm_epyc7002/drivers/net/ethernet/qualcomm/rmnet/rmnet_private.h
Subash Abhinov Kasiviswanathan c597897b08 net: qualcomm: rmnet: Define the MAPv4 packet formats
The MAPv4 packet format adds support for RX / TX checksum offload.
For a bi-directional UDP stream at a rate of 570 / 146 Mbps, roughly
10% CPU cycles are saved.

For receive path, there is a checksum trailer appended to the end of
the MAP packet. The valid field indicates if hardware has computed
the checksum. csum_start_offset indicates the offset from the start
of the IP header from which hardware has computed checksum.
csum_length is the number of bytes over which the checksum was
computed and the resulting value is csum_value.

In the transmit path, a header is appended between the end of the MAP
header and the start of the IP packet. csum_start_offset is the offset
in bytes from which hardware will compute the checksum if the
csum_enabled bit is set. udp_ip4_ind indicates if the checksum
value of 0 is valid or not. csum_insert_offset is the offset from the
csum_start_offset where hardware will insert the computed checksum.

The use of this additional packet format for checksum offload is
explained in subsequent patches.

Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-08 13:58:49 -05:00

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C

/* Copyright (c) 2013-2014, 2016-2017 The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#ifndef _RMNET_PRIVATE_H_
#define _RMNET_PRIVATE_H_
#define RMNET_MAX_PACKET_SIZE 16384
#define RMNET_DFLT_PACKET_SIZE 1500
#define RMNET_NEEDED_HEADROOM 16
#define RMNET_TX_QUEUE_LEN 1000
/* Constants */
#define RMNET_INGRESS_FORMAT_DEAGGREGATION BIT(0)
#define RMNET_INGRESS_FORMAT_MAP_COMMANDS BIT(1)
#define RMNET_INGRESS_FORMAT_MAP_CKSUMV4 BIT(2)
#define RMNET_EGRESS_FORMAT_MAP_CKSUMV4 BIT(3)
/* Replace skb->dev to a virtual rmnet device and pass up the stack */
#define RMNET_EPMODE_VND (1)
/* Pass the frame directly to another device with dev_queue_xmit() */
#define RMNET_EPMODE_BRIDGE (2)
#endif /* _RMNET_PRIVATE_H_ */