[net PATCH v3] octeontx2-af: Validate NIX maximum LFs correctly

[Subbaraya Sundeep]

NIX maximum number of LFs can be set via devlink command
but that can be done before assigning any LFs to a PF/VF.
The condition used to check whether any LFs are assigned is
incorrect. This patch fixes that condition.

Fixes: dd7842878633 ("octeontx2-af: Add new devlink param to configure maximum usable NIX block LFs")
Signed-off-by: Subbaraya Sundeep <sbhatta@xxxxxxxxxxx>
---
v3 changes:
	None, updated changelog
v2 changes:
	Fixed AI review by updating error message
	Updated comment to mention modifying NIXLFs has to be done prior
	to attaching NIXLFs to any PFs/VFs.

 .../marvell/octeontx2/af/rvu_devlink.c        | 27 +++++++++++++------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/marvell/octeontx2/af/rvu_devlink.c b/drivers/net/ethernet/marvell/octeontx2/af/rvu_devlink.c
index 6494a9ee2f0d..3b47ecb44d51 100644
--- a/drivers/net/ethernet/marvell/octeontx2/af/rvu_devlink.c
+++ b/drivers/net/ethernet/marvell/octeontx2/af/rvu_devlink.c
@@ -1510,7 +1510,9 @@ static int rvu_af_dl_nix_maxlf_validate(struct devlink *devlink, u32 id,
 	struct rvu_devlink *rvu_dl = devlink_priv(devlink);
 	struct rvu *rvu = rvu_dl->rvu;
 	u16 max_nix0_lf, max_nix1_lf;
-	struct npc_mcam *mcam;
+	struct rvu_block *block;
+	int blkaddr = 0;
+	int free_lfs;
 	u64 cfg;
 
 	cfg = rvu_read64(rvu, BLKADDR_NIX0, NIX_AF_CONST2);
@@ -1518,14 +1520,23 @@ static int rvu_af_dl_nix_maxlf_validate(struct devlink *devlink, u32 id,
 	cfg = rvu_read64(rvu, BLKADDR_NIX1, NIX_AF_CONST2);
 	max_nix1_lf = cfg & 0xFFF;
 
-	/* Do not allow user to modify maximum NIX LFs while mcam entries
-	 * have already been assigned.
+	/* Do not allow user to modify maximum NIX LFs while NIX LFs
+	 * have already been assigned. Note that modifying NIX LFs count
+	 * can be done only before any LF attach requests from PFs and VFs
+	 * and not later or concurrently.
 	 */
-	mcam = &rvu->hw->mcam;
-	if (mcam->bmap_fcnt < mcam->bmap_entries) {
-		NL_SET_ERR_MSG_MOD(extack,
-				   "mcam entries have already been assigned, can't resize");
-		return -EPERM;
+	blkaddr = rvu_get_next_nix_blkaddr(rvu, blkaddr);
+	while (blkaddr) {
+		block = &rvu->hw->block[blkaddr];
+
+		free_lfs = rvu_rsrc_free_count(&block->lf);
+		if (free_lfs != block->lf.max) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "NIX LFs already assigned, can't resize");
+			return -EPERM;
+		}
+
+		blkaddr = rvu_get_next_nix_blkaddr(rvu, blkaddr);
 	}
 
 	if (max_nix0_lf && val.vu16 > max_nix0_lf) {
-- 
2.48.1