[PATCH API-NEXT v4] api: ones complement metadata

[psavol]

Added packet metadata for ones complement sum over IP
payload in a packet. Some NICs calculate the sum
during packet input (at least for IP fragments) and
store the value into the packet descriptor. This offloads
L4 checksum calculation for IP fragments as SW does not
need sum all payload data, but just combine pre-calculated
sums from packet descriptors and remove extra header fields
from the sum.

[Bill-Fischofer-Linaro]

@psavol please rebase to avoid merge conflict.

[lumag]

@psavol it would be nice if you can provide an example code, how this API function will fit into packet reassembly example.

[psavol]

From commit log: "This offloads L4 checksum
calculation for IP fragments as SW does not need sum
all payload data, but just combine pre-calculated
sums from packet descriptors and remove extra header fields
from the sum."

odp_packet_t frag[4];

uint32_t chksum = 0;

for (i = 0; i < 4; i++) {
  uint16_t sum;
  odp_packet_data_range_t range;

  sum =odp_packet_ones_comp(frag[i], &range);
  if (range.length == ip_payload_len)
     chksum += sum;
  else {
    // tune the sum according to offset/len, or when length == 0 calculate the sum in SW
   }
}

// fold the chksum, etc...

[muvarov]

From: "Savolainen, Petri (Nokia - FI/Espoo)" 
 Ping.

> -----Original Message-----
> From: lng-odp [mailto:lng-odp-bounces@lists.linaro.org] On Behalf Of
> Github ODP bot
> Sent: Thursday, October 26, 2017 3:00 PM
> To: lng-odp@lists.linaro.org
> Subject: [lng-odp] [PATCH API-NEXT v3 0/3] api: ones complement metadata
> 
> Added packet metadata for ones complement sum over IP
> payload in a packet. Some NICs calculate the sum
> during packet input (at least for IP fragments) and
> store the value into the packet descriptor. This offloads
> L4 checksum calculation for IP fragments as SW does not
> need sum all payload data, but just combine pre-calculated
> sums from packet descriptors and remove extra header fields
> from the sum.
> 
> ----------------github------------------------
> /** Email created from pull request 242 (psavol:next-checksum-metadata)
>  ** https://github.com/Linaro/odp/pull/242
>  ** Patch: https://github.com/Linaro/odp/pull/242.patch
>  ** Base sha: 63d92eb289261d1534b5b9e1e04291faa5e45d30
>  ** Merge commit sha: 5c16247e4ce2735df80c66f11dd9c9708e8c905f
>  **/
> ----------------/github------------------------
> 
> ----------------checkpatch.pl------------------------
> total: 0 errors, 0 warnings, 0 checks, 26 lines checked
> 
> 
> to_send-p-000.patch has no obvious style problems and is ready for
> submission.
> total: 0 errors, 0 warnings, 0 checks, 14 lines checked
> 
> 
> to_send-p-001.patch has no obvious style problems and is ready for
> submission.
> total: 0 errors, 0 warnings, 0 checks, 55 lines checked
> 
> 
> to_send-p-002.patch has no obvious style problems and is ready for
> submission.
> ----------------/checkpatch.pl------------------------
 

[lumag]

@muvarov @Bill-Fischofer-Linaro this was approved long ago. Can we get this in?

[muvarov]

please rename it without odp_. And I would move it inside loop and make it volatile then declaring somewhere on the top.

[psavol]

This is "static volatile uint64_t test_pktio_dummy_u64" in v4

[muvarov]

Merged.