net: hns3: fix possible mismatches resp of mailbox

Currently, the mailbox synchronous communication between VF and PF use
the following fields to maintain communication:
1. Origin_mbx_msg which was combined by message code and subcode, used
to match request and response.
2. Received_resp which means whether received response.

There may possible mismatches of the following situation:
1. VF sends message A with code=1 subcode=1.
2. PF was blocked about 500ms when processing the message A.
3. VF will detect message A timeout because it can't get the response
within 500ms.
4. VF sends message B with code=1 subcode=1 which equal message A.
5. PF processes the first message A and send the response message to
VF.
6. VF will identify the response matched the message B because the
code/subcode is the same. This will lead to mismatch of request and
response.

To fix the above bug, we use the following scheme:
1. The message sent from VF was labelled with match_id which was a
unique 16-bit non-zero value.
2. The response sent from PF will label with match_id which got from
the request.
3. The VF uses the match_id to match request and response message.

As for PF driver, it only needs to copy the match_id from request to
response.

Fixes: dde1a86e93ca ("net: hns3: Add mailbox support to PF driver")
Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

0 files changed, 0 insertions, 0 deletions