[PATCH net] octeontx2-af: skip CPT ctx flush command when no CPT LFs are attached

[PATCH net] octeontx2-af: skip CPT ctx flush command when no CPT LFs are attached

[kmahammadraf]

From: Srujana Challa <schalla@marvell.com>

CPT inline inbound LF command submission was attempted even when no CPT
LFs were mapped to the CPT PF. In that case, sending the uplink mailbox
message is unnecessary and can lead to avoidable failures/timeouts during
CPT context flush flow.

Add a guard in cpt_inline_inb_lf_cmd_send() to check mapped CPT LF count
for the CPT PF and return early when it is zero.

Signed-off-by: kmahammadraf <kmahammadraf@marvell.com>
Signed-off-by: Srujana Challa <schalla@marvell.com>
---
---
 drivers/net/ethernet/marvell/octeontx2/af/rvu_cpt.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/marvell/octeontx2/af/rvu_cpt.c b/drivers/net/ethernet/marvell/octeontx2/af/rvu_cpt.c
index f404117bf6c8..751643176c6d 100644
--- a/drivers/net/ethernet/marvell/octeontx2/af/rvu_cpt.c
+++ b/drivers/net/ethernet/marvell/octeontx2/af/rvu_cpt.c
@@ -1144,15 +1144,23 @@ int rvu_cpt_lf_teardown(struct rvu *rvu, u16 pcifunc, int blkaddr, int lf, int s
 static int cpt_inline_inb_lf_cmd_send(struct rvu *rvu, int blkaddr,
 				      int nix_blkaddr)
 {
-	int cpt_pf_num = rvu->cpt_pf_num;
+	int cpt_pf_num = rvu->cpt_pf_num, num_lfs;
 	struct cpt_inst_lmtst_req *req;
 	dma_addr_t res_daddr;
 	int timeout = 3000;
+	u16 pcifunc;
 	u8 cpt_idx;
 	u64 *inst;
 	u16 *res;
 	int rc;
 
+	pcifunc = (cpt_pf_num & RVU_OTX2_PFVF_PF_MASK) <<
+	      RVU_OTX2_PFVF_PF_SHIFT;
+	num_lfs = rvu_get_rsrc_mapcount(rvu_get_pfvf(rvu, pcifunc),
+					blkaddr);
+	if (num_lfs == 0)
+		return 0;
+
 	res = kzalloc(CPT_RES_LEN, GFP_KERNEL);
 	if (!res)
 		return -ENOMEM;
-- 
2.25.1

Re: [PATCH net] octeontx2-af: skip CPT ctx flush command when no CPT LFs are attached

[netdev-bot+sinfo]

Hi!

This is an automated message. This series looks like a fix, but its
commit messages seem to be missing some information:

 - How the issue was discovered, e.g. hit in production, hit during
   development, syzbot report, manual code inspection, LLM or static
   analysis tool scan.

 - Whether the issue was actually triggered, or is only theoretical
   (e.g. found by code inspection). If it was triggered please include
   the symptoms, like the stack trace or error messages.

 - What hardware the change was tested on. For driver fixes please
   mention the device (and if relevant firmware version) used for
   testing, or say that the change was not tested on real hardware.

Please do not repost the series just to address the above. Instead,
reply to this email with the missing information, so that reviewers
can take it into account. If the series needs another revision for
other reasons, please include the information in the commit messages
then.

The evaluation is done by an LLM so it may be wrong, if you think
that is the case please reply and explain.