net: airoha: Fix ETS priomap validation

ETS Qdisc schedules SP bands in a priority order assigning band-0 the
highest priority (band-0 > band-1 > .. > band-n) while EN7581 arranges
SP bands in a priority order assigning band-7 the highest priority
(band-7 > band-6, .. > band-n).
Fix priomap check in airoha_qdma_set_tx_ets_sched routine in order to
align ETS Qdisc and airoha_eth driver SP priority ordering.

Fixes: b56e4d6 ("net: airoha: Enforce ETS Qdisc priomap")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Link: https://patch.msgid.link/20250331-airoha-ets-validate-priomap-v1-1-60a524488672@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: LorenzoBianconi

drivers/net/ethernet/airoha/airoha_eth.c

@@ -2028,7 +2028,7 @@ static int airoha_qdma_set_tx_ets_sched(struct airoha_gdm_port *port,
 	struct tc_ets_qopt_offload_replace_params *p = &opt->replace_params;
 	enum tx_sched_mode mode = TC_SCH_SP;
 	u16 w[AIROHA_NUM_QOS_QUEUES] = {};
-	int i, nstrict = 0, nwrr, qidx;
+	int i, nstrict = 0;
 
 	if (p->bands > AIROHA_NUM_QOS_QUEUES)
 		return -EINVAL;
@@ -2046,17 +2046,17 @@ static int airoha_qdma_set_tx_ets_sched(struct airoha_gdm_port *port,
 	 * lowest priorities with respect to SP ones.
 	 * e.g: WRR0, WRR1, .., WRRm, SP0, SP1, .., SPn
 	 */
-	nwrr = p->bands - nstrict;
-	qidx = nstrict && nwrr ? nstrict : 0;
-	for (i = 1; i <= p->bands; i++) {
-		if (p->priomap[i % AIROHA_NUM_QOS_QUEUES] != qidx)
+	for (i = 0; i < nstrict; i++) {
+		if (p->priomap[p->bands - i - 1] != i)
 			return -EINVAL;
-
-		qidx = i == nwrr ? 0 : qidx + 1;
 	}
 
-	for (i = 0; i < nwrr; i++)
+	for (i = 0; i < p->bands - nstrict; i++) {
+		if (p->priomap[i] != nstrict + i)
+			return -EINVAL;
+
 		w[i] = p->weights[nstrict + i];
+	}
 
 	if (!nstrict)
 		mode = TC_SCH_WRR8;