common/cnxk: always use single interrupt ID with NIX

[ upstream commit 89d3557 ]

An errata exists whereby, in certain cases NIX may use an
incorrect QINT_IDX for SQ interrupts. As a result, the
interrupt may not be delivered to software, or may not be
associated with the correct SQ.
When NIX uses an incorrect QINT_IDX :
1. NIX_LF_QINT(0..63)_CNT[COUNT] will be incremented for
incorrect QINT.
2. NIX_LF_QINT(0..63)_INT[INTR] will be set for incorrect
QINT.

Fixes: ae06070 ("common/cnxk: add NIX Tx queue management API")

Signed-off-by: Harman Kalra <hkalra@marvell.com>
Acked-by: Jerin Jacob <jerinj@marvell.com>

drivers/common/cnxk/roc_nix_queue.c

@@ -695,7 +695,11 @@ sq_cn9k_init(struct nix *nix, struct roc_nix_sq *sq, uint32_t rr_quantum,
 	aq->sq.sq_int_ena |= BIT(NIX_SQINT_MNQ_ERR);
 
 	/* Many to one reduction */
-	aq->sq.qint_idx = sq->qid % nix->qints;
+	/* Assigning QINT 0 to all the SQs, an errata exists where NIXTX can
+	 * send incorrect QINT_IDX when reporting queue interrupt (QINT). This
+	 * might result in software missing the interrupt.
+	 */
+	aq->sq.qint_idx = 0;
 }
 
 static int
@@ -794,8 +798,11 @@ sq_init(struct nix *nix, struct roc_nix_sq *sq, uint32_t rr_quantum,
 	aq->sq.sq_int_ena |= BIT(NIX_SQINT_SEND_ERR);
 	aq->sq.sq_int_ena |= BIT(NIX_SQINT_MNQ_ERR);
 
-	/* Many to one reduction */
-	aq->sq.qint_idx = sq->qid % nix->qints;
+	/* Assigning QINT 0 to all the SQs, an errata exists where NIXTX can
+	 * send incorrect QINT_IDX when reporting queue interrupt (QINT). This
+	 * might result in software missing the interrupt.
+	 */
+	aq->sq.qint_idx = 0;
 }
 
 static int