mbox series

[net-next,v4,0/3] net: qualcomm: rmnet: Enable Mapv5

Message ID 1619121731-17782-1-git-send-email-sharathv@codeaurora.org
Headers show
Series net: qualcomm: rmnet: Enable Mapv5 | expand

Message

Sharath Chandra Vurukala April 22, 2021, 8:02 p.m. UTC
This series introduces the MAPv5 packet format.

  Patch 0 documents the MAPv4/v5.
  Patch 1 introduces the MAPv5 and the Inline checksum offload for RX/Ingress.
  Patch 2 introduces the MAPv5 and the Inline checksum offload for TX/Egress.

  A new checksum header format is used as part of MAPv5.For RX checksum offload,
  the checksum is verified by the HW and the validity is marked in the checksum
  header of MAPv5. For TX, the required metadata is filled up so hardware can
  compute the checksum.

  v1->v2:
  - Fixed the compilation errors, warnings reported by kernel test robot.
  - Checksum header definition is expanded to support big, little endian
          formats as mentioned by Jakub.

  v2->v3:
  - Fixed compilation errors reported by kernel bot for big endian flavor.

  v3->v4:
  - Made changes to use masks instead of C bit-fields as suggested by Jakub/Alex.

Sharath Chandra Vurukala (3):
  docs: networking: Add documentation for MAPv5
  net: ethernet: rmnet: Support for ingress MAPv5 checksum offload
  net: ethernet: rmnet: Add support for MAPv5 egress packets

 .../device_drivers/cellular/qualcomm/rmnet.rst     | 126 +++++++++++++++--
 drivers/net/ethernet/qualcomm/rmnet/rmnet_config.h |   4 +-
 .../net/ethernet/qualcomm/rmnet/rmnet_handlers.c   |  29 ++--
 drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h    |  11 +-
 .../net/ethernet/qualcomm/rmnet/rmnet_map_data.c   | 151 ++++++++++++++++++++-
 drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c    |   3 +-
 include/linux/if_rmnet.h                           |  27 +++-
 include/uapi/linux/if_link.h                       |   2 +
 8 files changed, 318 insertions(+), 35 deletions(-)

Comments

Alex Elder April 23, 2021, 12:54 a.m. UTC | #1
On 4/22/21 6:14 PM, subashab@codeaurora.org wrote:
> On 2021-04-22 14:14, Alex Elder wrote:

>> On 4/22/21 3:02 PM, Sharath Chandra Vurukala wrote:

>>> This series introduces the MAPv5 packet format.

>>>

>>>    Patch 0 documents the MAPv4/v5.

>>>    Patch 1 introduces the MAPv5 and the Inline checksum offload for 

>>> RX/Ingress.

>>>    Patch 2 introduces the MAPv5 and the Inline checksum offload for 

>>> TX/Egress.

>>

>> Was this supposed to be version 5?

>>

>> I already reviewed version 4.

>>

>> Please post version 5.  I am going to ignore this series.

>>

>>                     -Alex

>>

> 

> What are you talking about?

> 

> Patchwork shows that Sharath has posted upto v3 so far.


Sorry about that.  Sharath posted a series version 4 last week, which
I reviewed.  I mistakenly thought he had posted it for upstream review
and didn't realize he sent it to me (and others) privately.

Still, I said he should tag the second patch "Acked-by:" me and
he did not, so I assumed it was a repost of the same code.

I'll review this after all.

					-Alex

> 

> https://patchwork.kernel.org/project/netdevbpf/list/?submitter=197703&state=%2A&archive=both 

>
Alex Elder April 23, 2021, 12:31 p.m. UTC | #2
On 4/22/21 3:02 PM, Sharath Chandra Vurukala wrote:
> This series introduces the MAPv5 packet format.

> 

>    Patch 0 documents the MAPv4/v5.

>    Patch 1 introduces the MAPv5 and the Inline checksum offload for RX/Ingress.

>    Patch 2 introduces the MAPv5 and the Inline checksum offload for TX/Egress.

> 

>    A new checksum header format is used as part of MAPv5.For RX checksum offload,

>    the checksum is verified by the HW and the validity is marked in the checksum

>    header of MAPv5. For TX, the required metadata is filled up so hardware can

>    compute the checksum.


It turns out many of review comments from last week were
ignored without explanation.  So I will repeat some of them
this time.

I see one thing that I think might be a bug in the third
patch, but maybe I'm mistaken, and you can explain why.

I tested the code you supplied me last week, and with a
bug fix applied I found they worked for:
   IPA v3.5.1, IPv4 in loopback, checksum enabled and not
   IPA v4.2, IPv6 using LTE, checksum enabled and not
Both of the above tested ICMP, UDP, and TCP.  I will retest
with this series.

I did not test with IPA v4.5+, which is unfortunately
the main user of this new code.  I will try to do so
with your updated code, and if all testing passes I'll
send a message with "Tested-by" for you to add to your
patches.

					-Alex

>    v1->v2:

>    - Fixed the compilation errors, warnings reported by kernel test robot.

>    - Checksum header definition is expanded to support big, little endian

>            formats as mentioned by Jakub.

> 

>    v2->v3:

>    - Fixed compilation errors reported by kernel bot for big endian flavor.

> 

>    v3->v4:

>    - Made changes to use masks instead of C bit-fields as suggested by Jakub/Alex.

> 

> Sharath Chandra Vurukala (3):

>    docs: networking: Add documentation for MAPv5

>    net: ethernet: rmnet: Support for ingress MAPv5 checksum offload

>    net: ethernet: rmnet: Add support for MAPv5 egress packets

> 

>   .../device_drivers/cellular/qualcomm/rmnet.rst     | 126 +++++++++++++++--

>   drivers/net/ethernet/qualcomm/rmnet/rmnet_config.h |   4 +-

>   .../net/ethernet/qualcomm/rmnet/rmnet_handlers.c   |  29 ++--

>   drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h    |  11 +-

>   .../net/ethernet/qualcomm/rmnet/rmnet_map_data.c   | 151 ++++++++++++++++++++-

>   drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c    |   3 +-

>   include/linux/if_rmnet.h                           |  27 +++-

>   include/uapi/linux/if_link.h                       |   2 +

>   8 files changed, 318 insertions(+), 35 deletions(-)

>
Alex Elder April 23, 2021, 12:32 p.m. UTC | #3
On 4/22/21 3:02 PM, Sharath Chandra Vurukala wrote:
> Adding documentation explaining the new MAPv4/v5 packet formats

> and the corresponding checksum offload headers.

> 

> Signed-off-by: Sharath Chandra Vurukala <sharathv@codeaurora.org>



Thank you for updating this document, and in particular
for adding documentation for QMAPv4.

While I might suggest minor changes here or there to
wording, I think the document does a good enough job
of describing RMNet data structures.

My main interest right now is enabling inline checksum
offload functionality, so for now I'm content to just
acknowledge this patch.

Acked-by: Alex Elder <elder@linaro.org>


> ---

>   .../device_drivers/cellular/qualcomm/rmnet.rst     | 126 +++++++++++++++++++--

>   1 file changed, 114 insertions(+), 12 deletions(-)

> 

> diff --git a/Documentation/networking/device_drivers/cellular/qualcomm/rmnet.rst b/Documentation/networking/device_drivers/cellular/qualcomm/rmnet.rst

> index 70643b5..4118384 100644

> --- a/Documentation/networking/device_drivers/cellular/qualcomm/rmnet.rst

> +++ b/Documentation/networking/device_drivers/cellular/qualcomm/rmnet.rst

> @@ -27,34 +27,136 @@ these MAP frames and send them to appropriate PDN's.

>   2. Packet format

>   ================

>   

> -a. MAP packet (data / control)

> +a. MAP packet v1 (data / control)

>   

> -MAP header has the same endianness of the IP packet.

> +MAP header fields are in big endian format.

>   

>   Packet format::

>   

> -  Bit             0             1           2-7      8 - 15           16 - 31

> +  Bit             0             1           2-7      8-15           16-31

>     Function   Command / Data   Reserved     Pad   Multiplexer ID    Payload length

> -  Bit            32 - x

> -  Function     Raw  Bytes

> +

> +  Bit            32-x

> +  Function      Raw bytes

>   

>   Command (1)/ Data (0) bit value is to indicate if the packet is a MAP command

> -or data packet. Control packet is used for transport level flow control. Data

> +or data packet. Command packet is used for transport level flow control. Data

>   packets are standard IP packets.

>   

> -Reserved bits are usually zeroed out and to be ignored by receiver.

> +Reserved bits must be zero when sent and ignored when received.

>   

> -Padding is number of bytes to be added for 4 byte alignment if required by

> -hardware.

> +Padding is the number of bytes to be appended to the payload to

> +ensure 4 byte alignment.

>   

>   Multiplexer ID is to indicate the PDN on which data has to be sent.

>   

>   Payload length includes the padding length but does not include MAP header

>   length.

>   

> -b. MAP packet (command specific)::

> +b. Map packet v4 (data / control)

> +

> +MAP header fields are in big endian format.

> +

> +Packet format::

> +

> +  Bit             0             1           2-7      8-15           16-31

> +  Function   Command / Data   Reserved     Pad   Multiplexer ID    Payload length

> +

> +  Bit            32-(x-33)      (x-32)-x

> +  Function      Raw bytes      Checksum offload header

> +

> +Command (1)/ Data (0) bit value is to indicate if the packet is a MAP command

> +or data packet. Command packet is used for transport level flow control. Data

> +packets are standard IP packets.

> +

> +Reserved bits must be zero when sent and ignored when received.

> +

> +Padding is the number of bytes to be appended to the payload to

> +ensure 4 byte alignment.

> +

> +Multiplexer ID is to indicate the PDN on which data has to be sent.

> +

> +Payload length includes the padding length but does not include MAP header

> +length.

> +

> +Checksum offload header, has the information about the checksum processing done

> +by the hardware.Checksum offload header fields are in big endian format.

> +

> +Packet format::

> +

> +  Bit             0-14        15              16-31

> +  Function      Reserved   Valid     Checksum start offset

> +

> +  Bit                31-47                    48-64

> +  Function      Checksum length           Checksum value

> +

> +Reserved bits must be zero when sent and ignored when received.

> +

> +Valid bit indicates whether the partial checksum is calculated and is valid.

> +Set to 1, if its is valid. Set to 0 otherwise.

> +

> +Padding is the number of bytes to be appended to the payload to

> +ensure 4 byte alignment.

> +

> +Checksum start offset, Indicates the offset in bytes from the beginning of the

> +IP header, from which modem computed checksum.

> +

> +Checksum length is the Length in bytes starting from CKSUM_START_OFFSET,

> +over which checksum is computed.

> +

> +Checksum value, indicates the checksum computed.

> +

> +c. MAP packet v5 (data / control)

> +

> +MAP header fields are in big endian format.

> +

> +Packet format::

> +

> +  Bit             0             1         2-7      8-15           16-31

> +  Function   Command / Data  Next header  Pad   Multiplexer ID   Payload length

> +

> +  Bit            32-x

> +  Function      Raw bytes

> +

> +Command (1)/ Data (0) bit value is to indicate if the packet is a MAP command

> +or data packet. Command packet is used for transport level flow control. Data

> +packets are standard IP packets.

> +

> +Next header is used to indicate the presence of another header, currently is

> +limited to checksum header.

> +

> +Padding is the number of bytes to be appended to the payload to

> +ensure 4 byte alignment.

> +

> +Multiplexer ID is to indicate the PDN on which data has to be sent.

> +

> +Payload length includes the padding length but does not include MAP header

> +length.

> +

> +d. Checksum offload header v5

> +

> +Checksum offload header fields are in big endian format.

> +

> +  Bit            0 - 6          7               8-15              16-31

> +  Function     Header Type    Next Header     Checksum Valid    Reserved

> +

> +Header Type is to indicate the type of header, this usually is set to CHECKSUM

> +

> +Header types

> += ==========================================

> +0 Reserved

> +1 Reserved

> +2 checksum header

> +

> +Checksum Valid is to indicate whether the header checksum is valid. Value of 1

> +implies that checksum is calculated on this packet and is valid, value of 0

> +indicates that the calculated packet checksum is invalid.

> +

> +Reserved bits must be zero when sent and ignored when received.

> +

> +e. MAP packet v1/v5 (command specific)::

>   

> -    Bit             0             1           2-7      8 - 15           16 - 31

> +    Bit             0             1         2-7      8 - 15           16 - 31

>       Function   Command         Reserved     Pad   Multiplexer ID    Payload length

>       Bit          32 - 39        40 - 45    46 - 47       48 - 63

>       Function   Command name    Reserved   Command Type   Reserved

> @@ -74,7 +176,7 @@ Command types

>   3 is for error during processing of commands

>   = ==========================================

>   

> -c. Aggregation

> +f. Aggregation

>   

>   Aggregation is multiple MAP packets (can be data or command) delivered to

>   rmnet in a single linear skb. rmnet will process the individual

>
Alex Elder April 23, 2021, 12:32 p.m. UTC | #4
On 4/22/21 3:02 PM, Sharath Chandra Vurukala wrote:
> Adding support for processing of MAPv5 downlink packets.

> It involves parsing the Mapv5 packet and checking the csum header

> to know whether the hardware has validated the checksum and is

> valid or not.

> 

> Based on the checksum valid bit the corresponding stats are

> incremented and skb->ip_summed is marked either CHECKSUM_UNNECESSARY

> or left as CHEKSUM_NONE to let network stack revalidate the checksum

> and update the respective snmp stats.

> 

> Current MAPV1 header has been modified, the reserved field in the

> Mapv1 header is now used for next header indication.

> 

> Signed-off-by: Sharath Chandra Vurukala <sharathv@codeaurora.org>


I have a few minor things I recommend you fix.

I don't see any bugs, but I'm not going to offer
"Reviewed-by" until you've had a chance to either
update your patch or explain why you won't.

> ---

>   .../net/ethernet/qualcomm/rmnet/rmnet_handlers.c   | 17 ++++---

>   drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h    |  3 +-

>   .../net/ethernet/qualcomm/rmnet/rmnet_map_data.c   | 58 +++++++++++++++++++++-

>   include/linux/if_rmnet.h                           | 27 +++++++++-

>   include/uapi/linux/if_link.h                       |  1 +

>   5 files changed, 97 insertions(+), 9 deletions(-)

> 

> diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c

> index 0be5ac7..706a225 100644

> --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c

> +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c

> @@ -1,5 +1,5 @@

>   // SPDX-License-Identifier: GPL-2.0-only

> -/* Copyright (c) 2013-2018, The Linux Foundation. All rights reserved.

> +/* Copyright (c) 2013-2018, 2021, The Linux Foundation. All rights reserved.

>    *

>    * RMNET Data ingress/egress handler

>    */

> @@ -82,11 +82,16 @@ __rmnet_map_ingress_handler(struct sk_buff *skb,

>   

>   	skb->dev = ep->egress_dev;

>   

> -	/* Subtract MAP header */

> -	skb_pull(skb, sizeof(struct rmnet_map_header));

> -	rmnet_set_skb_proto(skb);

> -

> -	if (port->data_format & RMNET_FLAGS_INGRESS_MAP_CKSUMV4) {

> +	if ((port->data_format & RMNET_FLAGS_INGRESS_MAP_CKSUMV5) &&

> +	    (map_header->flags & MAP_NEXT_HEADER_FLAG)) {

> +		if (rmnet_map_process_next_hdr_packet(skb, len))

> +			goto free_skb;

> +		skb_pull(skb, sizeof(*map_header));

> +		rmnet_set_skb_proto(skb);

> +	} else if (port->data_format & RMNET_FLAGS_INGRESS_MAP_CKSUMV4) {

> +		/* Subtract MAP header */

> +		skb_pull(skb, sizeof(*map_header));

> +		rmnet_set_skb_proto(skb);

>   		if (!rmnet_map_checksum_downlink_packet(skb, len + pad))

>   			skb->ip_summed = CHECKSUM_UNNECESSARY;

>   	}

> diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h

> index 2aea153..1a399bf 100644

> --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h

> +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map.h

> @@ -1,5 +1,5 @@

>   /* SPDX-License-Identifier: GPL-2.0-only */

> -/* Copyright (c) 2013-2018, The Linux Foundation. All rights reserved.

> +/* Copyright (c) 2013-2018, 2021, The Linux Foundation. All rights reserved.

>    */

>   

>   #ifndef _RMNET_MAP_H_

> @@ -48,5 +48,6 @@ void rmnet_map_command(struct sk_buff *skb, struct rmnet_port *port);

>   int rmnet_map_checksum_downlink_packet(struct sk_buff *skb, u16 len);

>   void rmnet_map_checksum_uplink_packet(struct sk_buff *skb,

>   				      struct net_device *orig_dev);

> +int rmnet_map_process_next_hdr_packet(struct sk_buff *skb, u16 len);

>   

>   #endif /* _RMNET_MAP_H_ */

> diff --git a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c

> index 0ac2ff8..f427018 100644

> --- a/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c

> +++ b/drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c

> @@ -1,5 +1,5 @@

>   // SPDX-License-Identifier: GPL-2.0-only

> -/* Copyright (c) 2013-2018, The Linux Foundation. All rights reserved.

> +/* Copyright (c) 2013-2018, 2021, The Linux Foundation. All rights reserved.

>    *

>    * RMNET Data MAP protocol

>    */

> @@ -8,6 +8,7 @@

>   #include <linux/ip.h>

>   #include <linux/ipv6.h>

>   #include <net/ip6_checksum.h>

> +#include <linux/bitfield.h>

>   #include "rmnet_config.h"

>   #include "rmnet_map.h"

>   #include "rmnet_private.h"

> @@ -300,8 +301,11 @@ struct rmnet_map_header *rmnet_map_add_map_header(struct sk_buff *skb,

>   struct sk_buff *rmnet_map_deaggregate(struct sk_buff *skb,

>   				      struct rmnet_port *port)

>   {

> +	struct rmnet_map_v5_csum_header *next_hdr = NULL;

> +	unsigned char *data = skb->data;


If you define the data variable to have (void *) type you can
get rid of some casts below, and it won't need to use a cast
when assigned here either.

>   	struct rmnet_map_header *maph;

>   	struct sk_buff *skbn;

> +	u8 nexthdr_type;

>   	u32 packet_len;

>   

>   	if (skb->len == 0)

> @@ -312,6 +316,17 @@ struct sk_buff *rmnet_map_deaggregate(struct sk_buff *skb,

>   

>   	if (port->data_format & RMNET_FLAGS_INGRESS_MAP_CKSUMV4)

>   		packet_len += sizeof(struct rmnet_map_dl_csum_trailer);

This block should be surrounded by curly braces.  If one block
in an if statement (or chain of them) has them, they all should.

> +	else if (port->data_format & RMNET_FLAGS_INGRESS_MAP_CKSUMV5) {

> +		if (!(maph->flags & MAP_CMD_FLAG)) {

> +			packet_len += sizeof(struct rmnet_map_v5_csum_header);


		packet_len += sizeof(*next_hdr);

> +			if (maph->flags & MAP_NEXT_HEADER_FLAG)

> +				next_hdr = (struct rmnet_map_v5_csum_header *)

> +						(data + sizeof(*maph));



If data is a void pointer, this could be:
				next_hdr = data + sizeof(*maph);

> +			else

> +				/* Mapv5 data pkt without csum hdr is invalid */

> +				return NULL;

> +		}

> +	}

>   

>   	if (((int)skb->len - (int)packet_len) < 0)

>   		return NULL;

> @@ -320,6 +335,13 @@ struct sk_buff *rmnet_map_deaggregate(struct sk_buff *skb,

>   	if (!maph->pkt_len)

>   		return NULL;

>   

> +	if (next_hdr) {

> +		nexthdr_type = u8_get_bits(next_hdr->header_info,

> +				MAPV5_HDRINFO_HDR_TYPE_FMASK);


Consider fixing the alignment of the second argument
above.

> +		if (nexthdr_type != RMNET_MAP_HEADER_TYPE_CSUM_OFFLOAD)

> +			return NULL;

> +	}

> +

>   	skbn = alloc_skb(packet_len + RMNET_MAP_DEAGGR_SPACING, GFP_ATOMIC);

>   	if (!skbn)

>   		return NULL;

> @@ -414,3 +436,37 @@ void rmnet_map_checksum_uplink_packet(struct sk_buff *skb,

>   

>   	priv->stats.csum_sw++;

>   }

> +

> +/* Process a MAPv5 packet header */

> +int rmnet_map_process_next_hdr_packet(struct sk_buff *skb,

> +				      u16 len)

> +{

> +	struct rmnet_priv *priv = netdev_priv(skb->dev);

> +	struct rmnet_map_v5_csum_header *next_hdr;

> +	u8 nexthdr_type;

> +	int rc = 0;

> +

> +	next_hdr = (struct rmnet_map_v5_csum_header *)(skb->data +

> +			sizeof(struct rmnet_map_header));

> +

> +	nexthdr_type = u8_get_bits(next_hdr->header_info,

> +			MAPV5_HDRINFO_HDR_TYPE_FMASK);


The arguments in the above two assignments don't look
aligned very well.  Maybe it's just the way my mail
program is displaying it.

> +

> +	if (nexthdr_type == RMNET_MAP_HEADER_TYPE_CSUM_OFFLOAD) {

> +		if (unlikely(!(skb->dev->features & NETIF_F_RXCSUM))) {

> +			priv->stats.csum_sw++;

> +		} else if (next_hdr->csum_info & MAPV5_CSUMINFO_VALID_FLAG) {

> +			priv->stats.csum_ok++;

> +			skb->ip_summed = CHECKSUM_UNNECESSARY;

> +		} else {

> +			priv->stats.csum_valid_unset++;

> +		}

> +

> +		/* Pull csum v5 header */

> +		skb_pull(skb, sizeof(struct rmnet_map_v5_csum_header));


		skb_pull(skb, sizeof(*next_hdr);

> +	} else

> +		return -EINVAL;


Please add curly braces here too.

> +

> +	return rc;

> +}

> +

> diff --git a/include/linux/if_rmnet.h b/include/linux/if_rmnet.h

> index 4efb537..f82e37e 100644

> --- a/include/linux/if_rmnet.h

> +++ b/include/linux/if_rmnet.h

> @@ -1,5 +1,5 @@

>   /* SPDX-License-Identifier: GPL-2.0-only

> - * Copyright (c) 2013-2019, The Linux Foundation. All rights reserved.

> + * Copyright (c) 2013-2019, 2021 The Linux Foundation. All rights reserved.

>    */

>   

>   #ifndef _LINUX_IF_RMNET_H_

> @@ -14,8 +14,10 @@ struct rmnet_map_header {

>   /* rmnet_map_header flags field:

>    *  PAD_LEN:	number of pad bytes following packet data

>    *  CMD:	1 = packet contains a MAP command; 0 = packet contains data

> + *  NEXT_HEADER	1 = packet contains V5 CSUM header 0 = no V5 CSUM header

>    */

>   #define MAP_PAD_LEN_MASK		GENMASK(5, 0)

> +#define MAP_NEXT_HEADER_FLAG		BIT(6)

>   #define MAP_CMD_FLAG			BIT(7)

>   

>   struct rmnet_map_dl_csum_trailer {

> @@ -45,4 +47,27 @@ struct rmnet_map_ul_csum_header {

>   #define MAP_CSUM_UL_UDP_FLAG		BIT(14)

>   #define MAP_CSUM_UL_ENABLED_FLAG	BIT(15)

>   

> +/* MAP CSUM headers */

> +struct rmnet_map_v5_csum_header {

> +	u8 header_info;

> +	u8 csum_info;

> +	__be16 reserved;

> +} __aligned(1);

> +

> +/* v5 header_info field

> + * NEXT_HEADER:  Represents whether there is any other header

> + * HEADER TYPE: represents the type of this header

> + *

> + * csum_info field

> + * CSUM_VALID_OR_REQ:

> + * 1 = for UL, checksum computation is requested.

> + * 1 = for DL, validated the checksum and has found it valid

> + */

> +

> +#define MAPV5_HDRINFO_NXT_HDR_FLAG	BIT(0)

> +#define MAPV5_HDRINFO_HDR_TYPE_SHIFT	1

> +#define MAPV5_HDRINFO_HDR_TYPE_FMASK	GENMASK(7, MAPV5_HDRINFO_HDR_TYPE_SHIFT)


This is the only place you use MAPV5_HDRINFO_TYPE_SHIFT.
Defining and using it here immediately after its definition
subtracts, rather than adds value.  Just do:

#define MAPV5_HDRINFO_HDR_TYPE_FMASK	GENMASK(7, 1)

					-Alex

> +#define MAPV5_CSUMINFO_VALID_FLAG	BIT(7)

> +

> +#define RMNET_MAP_HEADER_TYPE_CSUM_OFFLOAD 2

>   #endif /* !(_LINUX_IF_RMNET_H_) */

> diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h

> index 91c8dda..21529b3 100644

> --- a/include/uapi/linux/if_link.h

> +++ b/include/uapi/linux/if_link.h

> @@ -1235,6 +1235,7 @@ enum {

>   #define RMNET_FLAGS_INGRESS_MAP_COMMANDS          (1U << 1)

>   #define RMNET_FLAGS_INGRESS_MAP_CKSUMV4           (1U << 2)

>   #define RMNET_FLAGS_EGRESS_MAP_CKSUMV4            (1U << 3)

> +#define RMNET_FLAGS_INGRESS_MAP_CKSUMV5           (1U << 4)

>   

>   enum {

>   	IFLA_RMNET_UNSPEC,

>