3 files changed, 18 insertions, 12 deletions

diff --git a/sys/dev/cxgbe/adapter.h b/sys/dev/cxgbe/adapter.h
index 9efaa70c6e38..fd5487b01179 100644
--- a/sys/dev/cxgbe/adapter.h
+++ b/sys/dev/cxgbe/adapter.h
@@ -685,7 +685,9 @@ struct sge_wrq {
 
 #define INVALID_NM_RXQ_CNTXT_ID ((uint16_t)(-1))
 struct sge_nm_rxq {
-	volatile int nm_state;	/* NM_OFF, NM_ON, or NM_BUSY */
+	/* Items used by the driver rx ithread are in this cacheline. */
+	volatile int nm_state __aligned(CACHE_LINE_SIZE);	/* NM_OFF, NM_ON, or NM_BUSY */
+	u_int nid;		/* netmap ring # for this queue */
 	struct vi_info *vi;
 
 	struct iq_desc *iq_desc;
@@ -694,19 +696,22 @@ struct sge_nm_rxq {
 	uint16_t iq_cidx;
 	uint16_t iq_sidx;
 	uint8_t iq_gen;
+	uint32_t fl_sidx;
 
-	__be64  *fl_desc;
+	/* Items used by netmap rxsync are in this cacheline. */
+	__be64  *fl_desc __aligned(CACHE_LINE_SIZE);
 	uint16_t fl_cntxt_id;
-	uint32_t fl_cidx;
 	uint32_t fl_pidx;
-	uint32_t fl_sidx;
+	uint32_t fl_sidx2;	/* copy of fl_sidx */
 	uint32_t fl_db_val;
-	u_int fl_hwidx:4;
-
 	u_int fl_db_saved;
-	u_int nid;		/* netmap ring # for this queue */
+	u_int fl_hwidx:4;
 
-	/* infrequently used items after this */
+	/*
+	 * fl_cidx is used by both the ithread and rxsync, the rest are not used
+	 * in the rx fast path.
+	 */
+	uint32_t fl_cidx __aligned(CACHE_LINE_SIZE);
 
 	bus_dma_tag_t iq_desc_tag;
 	bus_dmamap_t iq_desc_map;
@@ -716,7 +721,7 @@ struct sge_nm_rxq {
 	bus_dma_tag_t fl_desc_tag;
 	bus_dmamap_t fl_desc_map;
 	bus_addr_t fl_ba;
-} __aligned(CACHE_LINE_SIZE);
+};
 
 #define INVALID_NM_TXQ_CNTXT_ID ((u_int)(-1))
 struct sge_nm_txq {
diff --git a/sys/dev/cxgbe/t4_netmap.c b/sys/dev/cxgbe/t4_netmap.c
index 221ad823eb7f..c108d9b6a14d 100644
--- a/sys/dev/cxgbe/t4_netmap.c
+++ b/sys/dev/cxgbe/t4_netmap.c
@@ -921,7 +921,7 @@ cxgbe_netmap_rxsync(struct netmap_kring *kring, int flags)
 		MPASS((n & 7) == 0);
 
 		IDXINCR(kring->nr_hwcur, n, kring->nkr_num_slots);
-		IDXINCR(nm_rxq->fl_pidx, n, nm_rxq->fl_sidx);
+		IDXINCR(nm_rxq->fl_pidx, n, nm_rxq->fl_sidx2);
 
 		while (n > 0) {
 			for (i = 0; i < 8; i++, fl_pidx++, slot++) {
@@ -929,10 +929,10 @@ cxgbe_netmap_rxsync(struct netmap_kring *kring, int flags)
 				MPASS(ba != 0);
 				nm_rxq->fl_desc[fl_pidx] = htobe64(ba | hwidx);
 				slot->flags &= ~NS_BUF_CHANGED;
-				MPASS(fl_pidx <= nm_rxq->fl_sidx);
+				MPASS(fl_pidx <= nm_rxq->fl_sidx2);
 			}
 			n -= 8;
-			if (fl_pidx == nm_rxq->fl_sidx) {
+			if (fl_pidx == nm_rxq->fl_sidx2) {
 				fl_pidx = 0;
 				slot = &ring->slot[0];
 			}
diff --git a/sys/dev/cxgbe/t4_sge.c b/sys/dev/cxgbe/t4_sge.c
index b4187a98b4a9..9943ea62a0e3 100644
--- a/sys/dev/cxgbe/t4_sge.c
+++ b/sys/dev/cxgbe/t4_sge.c
@@ -3655,6 +3655,7 @@ alloc_nm_rxq(struct vi_info *vi, struct sge_nm_rxq *nm_rxq, int intr_idx,
 	nm_rxq->iq_gen = F_RSPD_GEN;
 	nm_rxq->fl_pidx = nm_rxq->fl_cidx = 0;
 	nm_rxq->fl_sidx = na->num_rx_desc;
+	nm_rxq->fl_sidx2 = nm_rxq->fl_sidx;	/* copy for rxsync cacheline */
 	nm_rxq->intr_idx = intr_idx;
 	nm_rxq->iq_cntxt_id = INVALID_NM_RXQ_CNTXT_ID;