ionic: add tx/rx-push support with device Component Memory Buffers

The ionic device has on-board memory (CMB) that can be used
for descriptors as a way to speed descriptor access for faster
packet processing.  It is rumored to improve latency and/or
packets-per-second for some profiles of small packet traffic,
although your mileage may vary.

Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 151 insertions, 10 deletions

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_lif.c b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
index e0f28087671a..957027e546b3 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_lif.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
@@ -26,9 +26,12 @@
 static const u8 ionic_qtype_versions[IONIC_QTYPE_MAX] = {
 	[IONIC_QTYPE_ADMINQ]  = 0,   /* 0 = Base version with CQ support */
 	[IONIC_QTYPE_NOTIFYQ] = 0,   /* 0 = Base version */
-	[IONIC_QTYPE_RXQ]     = 0,   /* 0 = Base version with CQ+SG support */
-	[IONIC_QTYPE_TXQ]     = 1,   /* 0 = Base version with CQ+SG support
-				      * 1 =   ... with Tx SG version 1
+	[IONIC_QTYPE_RXQ]     = 2,   /* 0 = Base version with CQ+SG support
+				      * 2 =       ... with CMB rings
+				      */
+	[IONIC_QTYPE_TXQ]     = 3,   /* 0 = Base version with CQ+SG support
+				      * 1 =       ... with Tx SG version 1
+				      * 3 =       ... with CMB rings
 				      */
 };
 
@@ -397,6 +400,15 @@ static void ionic_qcq_free(struct ionic_lif *lif, struct ionic_qcq *qcq)
 		qcq->q_base_pa = 0;
 	}
 
+	if (qcq->cmb_q_base) {
+		iounmap(qcq->cmb_q_base);
+		ionic_put_cmb(lif, qcq->cmb_pgid, qcq->cmb_order);
+		qcq->cmb_pgid = 0;
+		qcq->cmb_order = 0;
+		qcq->cmb_q_base = NULL;
+		qcq->cmb_q_base_pa = 0;
+	}
+
 	if (qcq->cq_base) {
 		dma_free_coherent(dev, qcq->cq_size, qcq->cq_base, qcq->cq_base_pa);
 		qcq->cq_base = NULL;
@@ -608,6 +620,7 @@ static int ionic_qcq_alloc(struct ionic_lif *lif, unsigned int type,
 		ionic_cq_map(&new->cq, cq_base, cq_base_pa);
 		ionic_cq_bind(&new->cq, &new->q);
 	} else {
+		/* regular DMA q descriptors */
 		new->q_size = PAGE_SIZE + (num_descs * desc_size);
 		new->q_base = dma_alloc_coherent(dev, new->q_size, &new->q_base_pa,
 						 GFP_KERNEL);
@@ -620,6 +633,33 @@ static int ionic_qcq_alloc(struct ionic_lif *lif, unsigned int type,
 		q_base_pa = ALIGN(new->q_base_pa, PAGE_SIZE);
 		ionic_q_map(&new->q, q_base, q_base_pa);
 
+		if (flags & IONIC_QCQ_F_CMB_RINGS) {
+			/* on-chip CMB q descriptors */
+			new->cmb_q_size = num_descs * desc_size;
+			new->cmb_order = order_base_2(new->cmb_q_size / PAGE_SIZE);
+
+			err = ionic_get_cmb(lif, &new->cmb_pgid, &new->cmb_q_base_pa,
+					    new->cmb_order);
+			if (err) {
+				netdev_err(lif->netdev,
+					   "Cannot allocate queue order %d from cmb: err %d\n",
+					   new->cmb_order, err);
+				goto err_out_free_q;
+			}
+
+			new->cmb_q_base = ioremap_wc(new->cmb_q_base_pa, new->cmb_q_size);
+			if (!new->cmb_q_base) {
+				netdev_err(lif->netdev, "Cannot map queue from cmb\n");
+				ionic_put_cmb(lif, new->cmb_pgid, new->cmb_order);
+				err = -ENOMEM;
+				goto err_out_free_q;
+			}
+
+			new->cmb_q_base_pa -= idev->phy_cmb_pages;
+			ionic_q_cmb_map(&new->q, new->cmb_q_base, new->cmb_q_base_pa);
+		}
+
+		/* cq DMA descriptors */
 		new->cq_size = PAGE_SIZE + (num_descs * cq_desc_size);
 		new->cq_base = dma_alloc_coherent(dev, new->cq_size, &new->cq_base_pa,
 						  GFP_KERNEL);
@@ -658,6 +698,10 @@ static int ionic_qcq_alloc(struct ionic_lif *lif, unsigned int type,
 err_out_free_cq:
 	dma_free_coherent(dev, new->cq_size, new->cq_base, new->cq_base_pa);
 err_out_free_q:
+	if (new->cmb_q_base) {
+		iounmap(new->cmb_q_base);
+		ionic_put_cmb(lif, new->cmb_pgid, new->cmb_order);
+	}
 	dma_free_coherent(dev, new->q_size, new->q_base, new->q_base_pa);
 err_out_free_cq_info:
 	vfree(new->cq.info);
@@ -739,6 +783,8 @@ static void ionic_qcq_sanitize(struct ionic_qcq *qcq)
 	qcq->cq.tail_idx = 0;
 	qcq->cq.done_color = 1;
 	memset(qcq->q_base, 0, qcq->q_size);
+	if (qcq->cmb_q_base)
+		memset_io(qcq->cmb_q_base, 0, qcq->cmb_q_size);
 	memset(qcq->cq_base, 0, qcq->cq_size);
 	memset(qcq->sg_base, 0, qcq->sg_size);
 }
@@ -758,6 +804,7 @@ static int ionic_lif_txq_init(struct ionic_lif *lif, struct ionic_qcq *qcq)
 			.index = cpu_to_le32(q->index),
 			.flags = cpu_to_le16(IONIC_QINIT_F_IRQ |
 					     IONIC_QINIT_F_SG),
+			.intr_index = cpu_to_le16(qcq->intr.index),
 			.pid = cpu_to_le16(q->pid),
 			.ring_size = ilog2(q->num_descs),
 			.ring_base = cpu_to_le64(q->base_pa),
@@ -766,17 +813,19 @@ static int ionic_lif_txq_init(struct ionic_lif *lif, struct ionic_qcq *qcq)
 			.features = cpu_to_le64(q->features),
 		},
 	};
-	unsigned int intr_index;
 	int err;
 
-	intr_index = qcq->intr.index;
-
-	ctx.cmd.q_init.intr_index = cpu_to_le16(intr_index);
+	if (qcq->flags & IONIC_QCQ_F_CMB_RINGS) {
+		ctx.cmd.q_init.flags |= cpu_to_le16(IONIC_QINIT_F_CMB);
+		ctx.cmd.q_init.ring_base = cpu_to_le64(qcq->cmb_q_base_pa);
+	}
 
 	dev_dbg(dev, "txq_init.pid %d\n", ctx.cmd.q_init.pid);
 	dev_dbg(dev, "txq_init.index %d\n", ctx.cmd.q_init.index);
 	dev_dbg(dev, "txq_init.ring_base 0x%llx\n", ctx.cmd.q_init.ring_base);
 	dev_dbg(dev, "txq_init.ring_size %d\n", ctx.cmd.q_init.ring_size);
+	dev_dbg(dev, "txq_init.cq_ring_base 0x%llx\n", ctx.cmd.q_init.cq_ring_base);
+	dev_dbg(dev, "txq_init.sg_ring_base 0x%llx\n", ctx.cmd.q_init.sg_ring_base);
 	dev_dbg(dev, "txq_init.flags 0x%x\n", ctx.cmd.q_init.flags);
 	dev_dbg(dev, "txq_init.ver %d\n", ctx.cmd.q_init.ver);
 	dev_dbg(dev, "txq_init.intr_index %d\n", ctx.cmd.q_init.intr_index);
@@ -834,6 +883,11 @@ static int ionic_lif_rxq_init(struct ionic_lif *lif, struct ionic_qcq *qcq)
 	};
 	int err;
 
+	if (qcq->flags & IONIC_QCQ_F_CMB_RINGS) {
+		ctx.cmd.q_init.flags |= cpu_to_le16(IONIC_QINIT_F_CMB);
+		ctx.cmd.q_init.ring_base = cpu_to_le64(qcq->cmb_q_base_pa);
+	}
+
 	dev_dbg(dev, "rxq_init.pid %d\n", ctx.cmd.q_init.pid);
 	dev_dbg(dev, "rxq_init.index %d\n", ctx.cmd.q_init.index);
 	dev_dbg(dev, "rxq_init.ring_base 0x%llx\n", ctx.cmd.q_init.ring_base);
@@ -2010,8 +2064,13 @@ static int ionic_txrx_alloc(struct ionic_lif *lif)
 		sg_desc_sz = sizeof(struct ionic_txq_sg_desc);
 
 	flags = IONIC_QCQ_F_TX_STATS | IONIC_QCQ_F_SG;
+
+	if (test_bit(IONIC_LIF_F_CMB_TX_RINGS, lif->state))
+		flags |= IONIC_QCQ_F_CMB_RINGS;
+
 	if (test_bit(IONIC_LIF_F_SPLIT_INTR, lif->state))
 		flags |= IONIC_QCQ_F_INTR;
+
 	for (i = 0; i < lif->nxqs; i++) {
 		err = ionic_qcq_alloc(lif, IONIC_QTYPE_TXQ, i, "tx", flags,
 				      num_desc, desc_sz, comp_sz, sg_desc_sz,
@@ -2032,6 +2091,9 @@ static int ionic_txrx_alloc(struct ionic_lif *lif)
 
 	flags = IONIC_QCQ_F_RX_STATS | IONIC_QCQ_F_SG | IONIC_QCQ_F_INTR;
 
+	if (test_bit(IONIC_LIF_F_CMB_RX_RINGS, lif->state))
+		flags |= IONIC_QCQ_F_CMB_RINGS;
+
 	num_desc = lif->nrxq_descs;
 	desc_sz = sizeof(struct ionic_rxq_desc);
 	comp_sz = sizeof(struct ionic_rxq_comp);
@@ -2707,6 +2769,55 @@ static const struct net_device_ops ionic_netdev_ops = {
 	.ndo_get_vf_stats       = ionic_get_vf_stats,
 };
 
+static int ionic_cmb_reconfig(struct ionic_lif *lif,
+			      struct ionic_queue_params *qparam)
+{
+	struct ionic_queue_params start_qparams;
+	int err = 0;
+
+	/* When changing CMB queue parameters, we're using limited
+	 * on-device memory and don't have extra memory to use for
+	 * duplicate allocations, so we free it all first then
+	 * re-allocate with the new parameters.
+	 */
+
+	/* Checkpoint for possible unwind */
+	ionic_init_queue_params(lif, &start_qparams);
+
+	/* Stop and free the queues */
+	ionic_stop_queues_reconfig(lif);
+	ionic_txrx_free(lif);
+
+	/* Set up new qparams */
+	ionic_set_queue_params(lif, qparam);
+
+	if (netif_running(lif->netdev)) {
+		/* Alloc and start the new configuration */
+		err = ionic_txrx_alloc(lif);
+		if (err) {
+			dev_warn(lif->ionic->dev,
+				 "CMB reconfig failed, restoring values: %d\n", err);
+
+			/* Back out the changes */
+			ionic_set_queue_params(lif, &start_qparams);
+			err = ionic_txrx_alloc(lif);
+			if (err) {
+				dev_err(lif->ionic->dev,
+					"CMB restore failed: %d\n", err);
+				goto errout;
+			}
+		}
+
+		ionic_start_queues_reconfig(lif);
+	} else {
+		/* This was detached in ionic_stop_queues_reconfig() */
+		netif_device_attach(lif->netdev);
+	}
+
+errout:
+	return err;
+}
+
 static void ionic_swap_queues(struct ionic_qcq *a, struct ionic_qcq *b)
 {
 	/* only swapping the queues, not the napi, flags, or other stuff */
@@ -2749,6 +2860,11 @@ int ionic_reconfigure_queues(struct ionic_lif *lif,
 	unsigned int flags, i;
 	int err = 0;
 
+	/* Are we changing q params while CMB is on */
+	if ((test_bit(IONIC_LIF_F_CMB_TX_RINGS, lif->state) && qparam->cmb_tx) ||
+	    (test_bit(IONIC_LIF_F_CMB_RX_RINGS, lif->state) && qparam->cmb_rx))
+		return ionic_cmb_reconfig(lif, qparam);
+
 	/* allocate temporary qcq arrays to hold new queue structs */
 	if (qparam->nxqs != lif->nxqs || qparam->ntxq_descs != lif->ntxq_descs) {
 		tx_qcqs = devm_kcalloc(lif->ionic->dev, lif->ionic->ntxqs_per_lif,
@@ -2785,6 +2901,16 @@ int ionic_reconfigure_queues(struct ionic_lif *lif,
 			sg_desc_sz = sizeof(struct ionic_txq_sg_desc);
 
 		for (i = 0; i < qparam->nxqs; i++) {
+			/* If missing, short placeholder qcq needed for swap */
+			if (!lif->txqcqs[i]) {
+				flags = IONIC_QCQ_F_TX_STATS | IONIC_QCQ_F_SG;
+				err = ionic_qcq_alloc(lif, IONIC_QTYPE_TXQ, i, "tx", flags,
+						      4, desc_sz, comp_sz, sg_desc_sz,
+						      lif->kern_pid, &lif->txqcqs[i]);
+				if (err)
+					goto err_out;
+			}
+
 			flags = lif->txqcqs[i]->flags & ~IONIC_QCQ_F_INTR;
 			err = ionic_qcq_alloc(lif, IONIC_QTYPE_TXQ, i, "tx", flags,
 					      num_desc, desc_sz, comp_sz, sg_desc_sz,
@@ -2804,6 +2930,16 @@ int ionic_reconfigure_queues(struct ionic_lif *lif,
 			comp_sz *= 2;
 
 		for (i = 0; i < qparam->nxqs; i++) {
+			/* If missing, short placeholder qcq needed for swap */
+			if (!lif->rxqcqs[i]) {
+				flags = IONIC_QCQ_F_RX_STATS | IONIC_QCQ_F_SG;
+				err = ionic_qcq_alloc(lif, IONIC_QTYPE_RXQ, i, "rx", flags,
+						      4, desc_sz, comp_sz, sg_desc_sz,
+						      lif->kern_pid, &lif->rxqcqs[i]);
+				if (err)
+					goto err_out;
+			}
+
 			flags = lif->rxqcqs[i]->flags & ~IONIC_QCQ_F_INTR;
 			err = ionic_qcq_alloc(lif, IONIC_QTYPE_RXQ, i, "rx", flags,
 					      num_desc, desc_sz, comp_sz, sg_desc_sz,
@@ -2853,10 +2989,15 @@ int ionic_reconfigure_queues(struct ionic_lif *lif,
 			lif->tx_coalesce_hw = lif->rx_coalesce_hw;
 		}
 
-		/* clear existing interrupt assignments */
+		/* Clear existing interrupt assignments.  We check for NULL here
+		 * because we're checking the whole array for potential qcqs, not
+		 * just those qcqs that have just been set up.
+		 */
 		for (i = 0; i < lif->ionic->ntxqs_per_lif; i++) {
-			ionic_qcq_intr_free(lif, lif->txqcqs[i]);
-			ionic_qcq_intr_free(lif, lif->rxqcqs[i]);
+			if (lif->txqcqs[i])
+				ionic_qcq_intr_free(lif, lif->txqcqs[i]);
+			if (lif->rxqcqs[i])
+				ionic_qcq_intr_free(lif, lif->rxqcqs[i]);
 		}
 
 		/* re-assign the interrupts */