[PATCH net-next 00/14] cleanups and RX path rewrite

[PATCH net-next 00/14] cleanups and RX path rewrite

[Jakub Kicinski]

Hi!

This series lays groundwork for upcoming XDP support by updating
the RX path not to pre-allocate sk_buffs.  I start with few
cleanups, removal of NFP3200-related code being the most significant.
Patch 7 moves to alloc_frag() and build_skb() APIs.  Again, a number
of small cleanups follow.  The set ends with adding support for
different number of RX and TX rings.

Jakub Kicinski (14):
  nfp: simplify nfp_net_poll()
  nfp: remove support for nfp3200
  nfp: remove unnecessary call to ether_setup()
  nfp: remove inline attributes and dead code
  nfp: centralize the buffer size calculation
  nfp: add buffer drop/recycle helper for RX
  nfp: use alloc_frag() and build_skb()
  nfp: add separate buffer allocation function for napi
  nfp: use AND instead of modulo to get ring indexes
  nfp: create separate define for max number of vectors
  nfp: use unsigned int for vector/ring counts
  nfp: remove nfp_net_irqs_wanted()
  nfp: replace num_irqs with max_r_vecs
  nfp: bring back support for different ring counts

 drivers/net/ethernet/netronome/nfp/nfp_net.h       |  43 +-
 .../net/ethernet/netronome/nfp/nfp_net_common.c    | 471 ++++++++++-----------
 drivers/net/ethernet/netronome/nfp/nfp_net_ctrl.h  |  13 +-
 .../net/ethernet/netronome/nfp/nfp_net_debugfs.c   |   9 +-
 .../net/ethernet/netronome/nfp/nfp_netvf_main.c    |  45 +-
 5 files changed, 263 insertions(+), 318 deletions(-)

-- 
1.9.1

[PATCH net-next 01/14] nfp: simplify nfp_net_poll()

[Jakub Kicinski]

There are few variables in nfp_net_poll() which are used only
once or unused but set.  Remove them.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
 drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index d365760fa75b..f6a42c14a1f0 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -1525,21 +1525,15 @@ static int nfp_net_poll(struct napi_struct *napi, int budget)
 {
 	struct nfp_net_r_vector *r_vec =
 		container_of(napi, struct nfp_net_r_vector, napi);
-	struct nfp_net_rx_ring *rx_ring = r_vec->rx_ring;
-	struct nfp_net_tx_ring *tx_ring = r_vec->tx_ring;
-	struct nfp_net *nn = r_vec->nfp_net;
-	struct netdev_queue *txq;
 	unsigned int pkts_polled;
 
-	tx_ring = &nn->tx_rings[rx_ring->idx];
-	txq = netdev_get_tx_queue(nn->netdev, tx_ring->idx);
-	nfp_net_tx_complete(tx_ring);
+	nfp_net_tx_complete(r_vec->tx_ring);
 
-	pkts_polled = nfp_net_rx(rx_ring, budget);
+	pkts_polled = nfp_net_rx(r_vec->rx_ring, budget);
 
 	if (pkts_polled < budget) {
 		napi_complete_done(napi, pkts_polled);
-		nfp_net_irq_unmask(nn, r_vec->irq_idx);
+		nfp_net_irq_unmask(r_vec->nfp_net, r_vec->irq_idx);
 	}
 
 	return pkts_polled;
-- 
1.9.1

[PATCH net-next 02/14] nfp: remove support for nfp3200

[Jakub Kicinski]

Drop all code related to nfp3200.  It was never widely deployed
as a NIC.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
 drivers/net/ethernet/netronome/nfp/nfp_net.h       |  7 +-
 .../net/ethernet/netronome/nfp/nfp_net_common.c    | 95 ++--------------------
 drivers/net/ethernet/netronome/nfp/nfp_net_ctrl.h  | 13 +--
 .../net/ethernet/netronome/nfp/nfp_netvf_main.c    | 45 ++--------
 4 files changed, 22 insertions(+), 138 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net.h b/drivers/net/ethernet/netronome/nfp/nfp_net.h
index ed824e11a1e3..808c38ae4991 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net.h
@@ -421,7 +421,6 @@ struct nfp_stat_pair {
  * @netdev:             Backpointer to net_device structure
  * @nfp_fallback:       Is the driver used in fallback mode?
  * @is_vf:              Is the driver attached to a VF?
- * @is_nfp3200:         Is the driver for a NFP-3200 card?
  * @fw_loaded:          Is the firmware loaded?
  * @bpf_offload_skip_sw:  Offloaded BPF program will not be rerun by cls_bpf
  * @ctrl:               Local copy of the control register/word.
@@ -487,7 +486,6 @@ struct nfp_net {
 
 	unsigned nfp_fallback:1;
 	unsigned is_vf:1;
-	unsigned is_nfp3200:1;
 	unsigned fw_loaded:1;
 	unsigned bpf_offload_skip_sw:1;
 
@@ -593,16 +591,13 @@ static inline void nn_writeb(struct nfp_net *nn, int off, u8 val)
 	writeb(val, nn->ctrl_bar + off);
 }
 
-/* NFP-3200 can't handle 16-bit accesses too well */
 static inline u16 nn_readw(struct nfp_net *nn, int off)
 {
-	WARN_ON_ONCE(nn->is_nfp3200);
 	return readw(nn->ctrl_bar + off);
 }
 
 static inline void nn_writew(struct nfp_net *nn, int off, u16 val)
 {
-	WARN_ON_ONCE(nn->is_nfp3200);
 	writew(val, nn->ctrl_bar + off);
 }
 
@@ -650,7 +645,7 @@ static inline void nn_pci_flush(struct nfp_net *nn)
 #define NFP_QCP_QUEUE_STS_HI			0x000c
 #define NFP_QCP_QUEUE_STS_HI_WRITEPTR_mask	0x3ffff
 
-/* The offset of a QCP queues in the PCIe Target (same on NFP3200 and NFP6000 */
+/* The offset of a QCP queues in the PCIe Target */
 #define NFP_PCIE_QUEUE(_q) (0x80000 + (NFP_QCP_QUEUE_ADDR_SZ * ((_q) & 0xff)))
 
 /* nfp_qcp_ptr - Read or Write Pointer of a queue */
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index f6a42c14a1f0..4e4b6e3b30d7 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -249,43 +249,14 @@ int nfp_net_reconfig(struct nfp_net *nn, u32 update)
  */
 
 /**
- * nfp_net_irq_unmask_msix() - Unmask MSI-X after automasking
- * @nn:       NFP Network structure
- * @entry_nr: MSI-X table entry
- *
- * Clear the MSI-X table mask bit for the given entry bypassing Linux irq
- * handling subsystem.  Use *only* to reenable automasked vectors.
- */
-static void nfp_net_irq_unmask_msix(struct nfp_net *nn, unsigned int entry_nr)
-{
-	struct list_head *msi_head = &nn->pdev->dev.msi_list;
-	struct msi_desc *entry;
-	u32 off;
-
-	/* All MSI-Xs have the same mask_base */
-	entry = list_first_entry(msi_head, struct msi_desc, list);
-
-	off = (PCI_MSIX_ENTRY_SIZE * entry_nr) +
-		PCI_MSIX_ENTRY_VECTOR_CTRL;
-	writel(0, entry->mask_base + off);
-	readl(entry->mask_base);
-}
-
-/**
  * nfp_net_irq_unmask() - Unmask automasked interrupt
  * @nn:       NFP Network structure
  * @entry_nr: MSI-X table entry
  *
- * If MSI-X auto-masking is enabled clear the mask bit, otherwise
- * clear the ICR for the entry.
+ * Clear the ICR for the IRQ entry.
  */
 static void nfp_net_irq_unmask(struct nfp_net *nn, unsigned int entry_nr)
 {
-	if (nn->ctrl & NFP_NET_CFG_CTRL_MSIXAUTO) {
-		nfp_net_irq_unmask_msix(nn, entry_nr);
-		return;
-	}
-
 	nn_writeb(nn, NFP_NET_CFG_ICR(entry_nr), NFP_NET_CFG_ICR_UNMASKED);
 	nn_pci_flush(nn);
 }
@@ -1368,20 +1339,6 @@ static void nfp_net_set_hash(struct net_device *netdev, struct sk_buff *skb,
  * more cleanly separate packet receive code from other bookkeeping
  * functions performed in the napi poll function.
  *
- * There are differences between the NFP-3200 firmware and the
- * NFP-6000 firmware.  The NFP-3200 firmware uses a dedicated RX queue
- * to indicate that new packets have arrived.  The NFP-6000 does not
- * have this queue and uses the DD bit in the RX descriptor. This
- * method cannot be used on the NFP-3200 as it causes a race
- * condition: The RX ring write pointer on the NFP-3200 is updated
- * after packets (and descriptors) have been DMAed.  If the DD bit is
- * used and subsequently the read pointer is updated this may lead to
- * the RX queue to underflow (if the firmware has not yet update the
- * write pointer).  Therefore we use slightly ugly conditional code
- * below to handle the differences.  We may, in the future update the
- * NFP-3200 firmware to behave the same as the firmware on the
- * NFP-6000.
- *
  * Return: Number of packets received.
  */
 static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget)
@@ -1389,41 +1346,19 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget)
 	struct nfp_net_r_vector *r_vec = rx_ring->r_vec;
 	struct nfp_net *nn = r_vec->nfp_net;
 	unsigned int data_len, meta_len;
-	int avail = 0, pkts_polled = 0;
 	struct sk_buff *skb, *new_skb;
 	struct nfp_net_rx_desc *rxd;
 	dma_addr_t new_dma_addr;
-	u32 qcp_wr_p;
+	int pkts_polled = 0;
 	int idx;
 
-	if (nn->is_nfp3200) {
-		/* Work out how many packets arrived */
-		qcp_wr_p = nfp_qcp_wr_ptr_read(rx_ring->qcp_rx);
-		idx = rx_ring->rd_p % rx_ring->cnt;
-
-		if (qcp_wr_p == idx)
-			/* No new packets */
-			return 0;
-
-		if (qcp_wr_p > idx)
-			avail = qcp_wr_p - idx;
-		else
-			avail = qcp_wr_p + rx_ring->cnt - idx;
-	} else {
-		avail = budget + 1;
-	}
-
-	while (avail > 0 && pkts_polled < budget) {
+	while (pkts_polled < budget) {
 		idx = rx_ring->rd_p % rx_ring->cnt;
 
 		rxd = &rx_ring->rxds[idx];
-		if (!(rxd->rxd.meta_len_dd & PCIE_DESC_RX_DD)) {
-			if (nn->is_nfp3200)
-				nn_dbg(nn, "RX descriptor not valid (DD)%d:%u rxd[0]=%#x rxd[1]=%#x\n",
-				       rx_ring->idx, idx,
-				       rxd->vals[0], rxd->vals[1]);
+		if (!(rxd->rxd.meta_len_dd & PCIE_DESC_RX_DD))
 			break;
-		}
+
 		/* Memory barrier to ensure that we won't do other reads
 		 * before the DD bit.
 		 */
@@ -1431,7 +1366,6 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget)
 
 		rx_ring->rd_p++;
 		pkts_polled++;
-		avail--;
 
 		skb = rx_ring->rxbufs[idx].skb;
 
@@ -1508,9 +1442,6 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget)
 		napi_gro_receive(&rx_ring->r_vec->napi, skb);
 	}
 
-	if (nn->is_nfp3200)
-		nfp_qcp_rd_ptr_add(rx_ring->qcp_rx, pkts_polled);
-
 	return pkts_polled;
 }
 
@@ -1895,9 +1826,8 @@ static void nfp_net_write_mac_addr(struct nfp_net *nn)
 {
 	nn_writel(nn, NFP_NET_CFG_MACADDR + 0,
 		  get_unaligned_be32(nn->netdev->dev_addr));
-	/* We can't do writew for NFP-3200 compatibility */
-	nn_writel(nn, NFP_NET_CFG_MACADDR + 4,
-		  get_unaligned_be16(nn->netdev->dev_addr + 4) << 16);
+	nn_writew(nn, NFP_NET_CFG_MACADDR + 6,
+		  get_unaligned_be16(nn->netdev->dev_addr + 4));
 }
 
 static void nfp_net_vec_clear_ring_data(struct nfp_net *nn, unsigned int idx)
@@ -2675,8 +2605,7 @@ static void nfp_net_del_vxlan_port(struct net_device *netdev,
  */
 void nfp_net_info(struct nfp_net *nn)
 {
-	nn_info(nn, "Netronome %s %sNetdev: TxQs=%d/%d RxQs=%d/%d\n",
-		nn->is_nfp3200 ? "NFP-32xx" : "NFP-6xxx",
+	nn_info(nn, "Netronome NFP-6xxx %sNetdev: TxQs=%d/%d RxQs=%d/%d\n",
 		nn->is_vf ? "VF " : "",
 		nn->num_tx_rings, nn->max_tx_rings,
 		nn->num_rx_rings, nn->max_rx_rings);
@@ -2891,13 +2820,7 @@ int nfp_net_netdev_init(struct net_device *netdev)
 		nn->ctrl |= NFP_NET_CFG_CTRL_IRQMOD;
 	}
 
-	/* On NFP-3200 enable MSI-X auto-masking, if supported and the
-	 * interrupts are not shared.
-	 */
-	if (nn->is_nfp3200 && nn->cap & NFP_NET_CFG_CTRL_MSIXAUTO)
-		nn->ctrl |= NFP_NET_CFG_CTRL_MSIXAUTO;
-
-	/* On NFP4000/NFP6000, determine RX packet/metadata boundary offset */
+	/* Determine RX packet/metadata boundary offset */
 	if (nn->fw_ver.major >= 2)
 		nn->rx_offset = nn_readl(nn, NFP_NET_CFG_RX_OFFSET);
 	else
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_ctrl.h b/drivers/net/ethernet/netronome/nfp/nfp_net_ctrl.h
index 93b10b441acb..385ba355c965 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_ctrl.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_ctrl.h
@@ -50,7 +50,7 @@
 /**
  * Configuration BAR size.
  *
- * The configuration BAR is 8K in size, but on the NFP6000, due to
+ * The configuration BAR is 8K in size, but due to
  * THB-350, 32k needs to be reserved.
  */
 #define NFP_NET_CFG_BAR_SZ              (32 * 1024)
@@ -186,18 +186,13 @@
 #define NFP_NET_CFG_START_RXQ           0x004c
 
 /**
- * NFP-3200 workaround (0x0050 - 0x0058)
- * @NFP_NET_CFG_SPARE_ADDR:  DMA address for ME code to use (e.g. YDS-155 fix)
- */
-#define NFP_NET_CFG_SPARE_ADDR          0x0050
-/**
- * NFP6000/NFP4000 - Prepend configuration
+ * Prepend configuration
  */
 #define NFP_NET_CFG_RX_OFFSET		0x0050
 #define NFP_NET_CFG_RX_OFFSET_DYNAMIC		0	/* Prepend mode */
 
 /**
- * NFP6000/NFP4000 - VXLAN/UDP encap configuration
+ * VXLAN/UDP encap configuration
  * @NFP_NET_CFG_VXLAN_PORT:	Base address of table of tunnels' UDP dst ports
  * @NFP_NET_CFG_VXLAN_SZ:	Size of the UDP port table in bytes
  */
@@ -205,7 +200,7 @@
 #define NFP_NET_CFG_VXLAN_SZ		  0x0008
 
 /**
- * NFP6000 - BPF section
+ * BPF section
  * @NFP_NET_CFG_BPF_ABI:	BPF ABI version
  * @NFP_NET_CFG_BPF_CAP:	BPF capabilities
  * @NFP_NET_CFG_BPF_MAX_LEN:	Maximum size of JITed BPF code in bytes
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_netvf_main.c b/drivers/net/ethernet/netronome/nfp/nfp_netvf_main.c
index 2800bbf65a89..d065235034d4 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_netvf_main.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_netvf_main.c
@@ -63,9 +63,7 @@ static void nfp_netvf_get_mac_addr(struct nfp_net *nn)
 	u8 mac_addr[ETH_ALEN];
 
 	put_unaligned_be32(nn_readl(nn, NFP_NET_CFG_MACADDR + 0), &mac_addr[0]);
-	/* We can't do readw for NFP-3200 compatibility */
-	put_unaligned_be16(nn_readl(nn, NFP_NET_CFG_MACADDR + 4) >> 16,
-			   &mac_addr[4]);
+	put_unaligned_be16(nn_readw(nn, NFP_NET_CFG_MACADDR + 6), &mac_addr[4]);
 
 	if (!is_valid_ether_addr(mac_addr)) {
 		eth_hw_addr_random(nn->netdev);
@@ -86,7 +84,6 @@ static int nfp_netvf_pci_probe(struct pci_dev *pdev,
 	int tx_bar_no, rx_bar_no;
 	u8 __iomem *ctrl_bar;
 	struct nfp_net *nn;
-	int is_nfp3200;
 	u32 startq;
 	int stride;
 	int err;
@@ -101,15 +98,6 @@ static int nfp_netvf_pci_probe(struct pci_dev *pdev,
 		goto err_pci_disable;
 	}
 
-	switch (pdev->device) {
-	case PCI_DEVICE_NFP6000VF:
-		is_nfp3200 = 0;
-		break;
-	default:
-		err = -ENODEV;
-		goto err_pci_regions;
-	}
-
 	pci_set_master(pdev);
 
 	err = dma_set_mask_and_coherent(&pdev->dev,
@@ -149,15 +137,9 @@ static int nfp_netvf_pci_probe(struct pci_dev *pdev,
 	} else {
 		switch (fw_ver.major) {
 		case 1 ... 4:
-			if (is_nfp3200) {
-				stride = 2;
-				tx_bar_no = NFP_NET_Q0_BAR;
-				rx_bar_no = NFP_NET_Q1_BAR;
-			} else {
-				stride = 4;
-				tx_bar_no = NFP_NET_Q0_BAR;
-				rx_bar_no = tx_bar_no;
-			}
+			stride = 4;
+			tx_bar_no = NFP_NET_Q0_BAR;
+			rx_bar_no = tx_bar_no;
 			break;
 		default:
 			dev_err(&pdev->dev, "Unsupported Firmware ABI %d.%d.%d.%d\n",
@@ -189,20 +171,10 @@ static int nfp_netvf_pci_probe(struct pci_dev *pdev,
 		max_rx_rings = (rx_bar_sz / NFP_QCP_QUEUE_ADDR_SZ) / 2;
 	}
 
-	/* XXX Implement a workaround for THB-350 here.  Ideally, we
-	 * have a different PCI ID for A rev VFs.
-	 */
-	switch (pdev->device) {
-	case PCI_DEVICE_NFP6000VF:
-		startq = readl(ctrl_bar + NFP_NET_CFG_START_TXQ);
-		tx_bar_off = NFP_PCIE_QUEUE(startq);
-		startq = readl(ctrl_bar + NFP_NET_CFG_START_RXQ);
-		rx_bar_off = NFP_PCIE_QUEUE(startq);
-		break;
-	default:
-		err = -ENODEV;
-		goto err_ctrl_unmap;
-	}
+	startq = readl(ctrl_bar + NFP_NET_CFG_START_TXQ);
+	tx_bar_off = NFP_PCIE_QUEUE(startq);
+	startq = readl(ctrl_bar + NFP_NET_CFG_START_RXQ);
+	rx_bar_off = NFP_PCIE_QUEUE(startq);
 
 	/* Allocate and initialise the netdev */
 	nn = nfp_net_netdev_alloc(pdev, max_tx_rings, max_rx_rings);
@@ -214,7 +186,6 @@ static int nfp_netvf_pci_probe(struct pci_dev *pdev,
 	nn->fw_ver = fw_ver;
 	nn->ctrl_bar = ctrl_bar;
 	nn->is_vf = 1;
-	nn->is_nfp3200 = is_nfp3200;
 	nn->stride_tx = stride;
 	nn->stride_rx = stride;
 
-- 
1.9.1

[PATCH net-next 03/14] nfp: remove unnecessary call to ether_setup()

[Jakub Kicinski]

ether_setup() will be invoked by alloc_etherdev_mqs(), no need
to call it again.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
 drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index 4e4b6e3b30d7..bd28e42bee2b 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -2839,7 +2839,6 @@ int nfp_net_netdev_init(struct net_device *netdev)
 		return err;
 
 	/* Finalise the netdev setup */
-	ether_setup(netdev);
 	netdev->netdev_ops = &nfp_net_netdev_ops;
 	netdev->watchdog_timeo = msecs_to_jiffies(5 * 1000);
 
-- 
1.9.1

[PATCH net-next 04/14] nfp: remove inline attributes and dead code

[Jakub Kicinski]

Don't declare functions as static inline in .c files and
remove dead code it was hiding.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
 drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 15 +--------------
 1 file changed, 1 insertion(+), 14 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index bd28e42bee2b..025483fb9103 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -576,7 +576,7 @@ static void nfp_net_aux_irq_free(struct nfp_net *nn, u32 ctrl_offset,
  *
  * Return: True if the ring is full.
  */
-static inline int nfp_net_tx_full(struct nfp_net_tx_ring *tx_ring, int dcnt)
+static int nfp_net_tx_full(struct nfp_net_tx_ring *tx_ring, int dcnt)
 {
 	return (tx_ring->wr_p - tx_ring->rd_p) >= (tx_ring->cnt - dcnt);
 }
@@ -1032,19 +1032,6 @@ static void nfp_net_tx_timeout(struct net_device *netdev)
  */
 
 /**
- * nfp_net_rx_space() - return the number of free slots on the RX ring
- * @rx_ring:   RX ring structure
- *
- * Make sure we leave at least one slot free.
- *
- * Return: True if there is space on the RX ring
- */
-static inline int nfp_net_rx_space(struct nfp_net_rx_ring *rx_ring)
-{
-	return (rx_ring->cnt - 1) - (rx_ring->wr_p - rx_ring->rd_p);
-}
-
-/**
  * nfp_net_rx_alloc_one() - Allocate and map skb for RX
  * @rx_ring:	RX ring structure of the skb
  * @dma_addr:	Pointer to storage for DMA address (output param)
-- 
1.9.1

[PATCH net-next 05/14] nfp: centralize the buffer size calculation

[Jakub Kicinski]

Add a helper function to calculate the buffer size at run time.
Buffer lengths will now depend on the FW prepend configuration
instead of assuming the most space consuming configuration and
defaulting to 2k buffers at initialization time.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
 drivers/net/ethernet/netronome/nfp/nfp_net.h       |  1 -
 .../net/ethernet/netronome/nfp/nfp_net_common.c    | 29 ++++++++++++++++------
 2 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net.h b/drivers/net/ethernet/netronome/nfp/nfp_net.h
index 808c38ae4991..9b90fab8a6df 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net.h
@@ -75,7 +75,6 @@
 
 /* Default size for MTU and freelist buffer sizes */
 #define NFP_NET_DEFAULT_MTU		1500
-#define NFP_NET_DEFAULT_RX_BUFSZ	2048
 
 /* Maximum number of bytes prepended to a packet */
 #define NFP_NET_MAX_PREPEND		64
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index 025483fb9103..77c645abb827 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -1030,6 +1030,19 @@ static void nfp_net_tx_timeout(struct net_device *netdev)
 
 /* Receive processing
  */
+static unsigned int
+nfp_net_calc_fl_bufsz(struct nfp_net *nn, unsigned int mtu)
+{
+	unsigned int fl_bufsz;
+
+	if (nn->rx_offset == NFP_NET_CFG_RX_OFFSET_DYNAMIC)
+		fl_bufsz = NFP_NET_MAX_PREPEND;
+	else
+		fl_bufsz = nn->rx_offset;
+	fl_bufsz += ETH_HLEN + VLAN_HLEN * 2 + mtu;
+
+	return fl_bufsz;
+}
 
 /**
  * nfp_net_rx_alloc_one() - Allocate and map skb for RX
@@ -2191,7 +2204,7 @@ static int nfp_net_change_mtu(struct net_device *netdev, int new_mtu)
 
 	old_mtu = netdev->mtu;
 	old_fl_bufsz = nn->fl_bufsz;
-	new_fl_bufsz = NFP_NET_MAX_PREPEND + ETH_HLEN + VLAN_HLEN * 2 + new_mtu;
+	new_fl_bufsz = nfp_net_calc_fl_bufsz(nn, new_mtu);
 
 	if (!netif_running(netdev)) {
 		netdev->mtu = new_mtu;
@@ -2731,12 +2744,18 @@ int nfp_net_netdev_init(struct net_device *netdev)
 
 	nfp_net_write_mac_addr(nn);
 
+	/* Determine RX packet/metadata boundary offset */
+	if (nn->fw_ver.major >= 2)
+		nn->rx_offset = nn_readl(nn, NFP_NET_CFG_RX_OFFSET);
+	else
+		nn->rx_offset = NFP_NET_RX_OFFSET;
+
 	/* Set default MTU and Freelist buffer size */
 	if (nn->max_mtu < NFP_NET_DEFAULT_MTU)
 		netdev->mtu = nn->max_mtu;
 	else
 		netdev->mtu = NFP_NET_DEFAULT_MTU;
-	nn->fl_bufsz = NFP_NET_DEFAULT_RX_BUFSZ;
+	nn->fl_bufsz = nfp_net_calc_fl_bufsz(nn, netdev->mtu);
 
 	/* Advertise/enable offloads based on capabilities
 	 *
@@ -2807,12 +2826,6 @@ int nfp_net_netdev_init(struct net_device *netdev)
 		nn->ctrl |= NFP_NET_CFG_CTRL_IRQMOD;
 	}
 
-	/* Determine RX packet/metadata boundary offset */
-	if (nn->fw_ver.major >= 2)
-		nn->rx_offset = nn_readl(nn, NFP_NET_CFG_RX_OFFSET);
-	else
-		nn->rx_offset = NFP_NET_RX_OFFSET;
-
 	/* Stash the re-configuration queue away.  First odd queue in TX Bar */
 	nn->qcp_cfg = nn->tx_bar + NFP_QCP_QUEUE_ADDR_SZ;
 
-- 
1.9.1

[PATCH net-next 06/14] nfp: add buffer drop/recycle helper for RX

[Jakub Kicinski]

nfp_net_rx() is quite long already and about to get longer.
Move buffer drop/recycle to a helper.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
 .../net/ethernet/netronome/nfp/nfp_net_common.c    | 27 ++++++++++++++--------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index 77c645abb827..abd4f17e89c7 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -1330,6 +1330,20 @@ static void nfp_net_set_hash(struct net_device *netdev, struct sk_buff *skb,
 	return data;
 }
 
+static void
+nfp_net_rx_drop(struct nfp_net_r_vector *r_vec, struct nfp_net_rx_ring *rx_ring,
+		struct nfp_net_rx_buf *rxbuf, struct sk_buff *skb)
+{
+	u64_stats_update_begin(&r_vec->rx_sync);
+	r_vec->rx_drops++;
+	u64_stats_update_end(&r_vec->rx_sync);
+
+	if (rxbuf)
+		nfp_net_rx_give_one(rx_ring, rxbuf->skb, rxbuf->dma_addr);
+	if (skb)
+		dev_kfree_skb_any(skb);
+}
+
 /**
  * nfp_net_rx() - receive up to @budget packets on @rx_ring
  * @rx_ring:   RX ring to receive from
@@ -1372,11 +1386,8 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget)
 		new_skb = nfp_net_rx_alloc_one(rx_ring, &new_dma_addr,
 					       nn->fl_bufsz);
 		if (!new_skb) {
-			nfp_net_rx_give_one(rx_ring, rx_ring->rxbufs[idx].skb,
-					    rx_ring->rxbufs[idx].dma_addr);
-			u64_stats_update_begin(&r_vec->rx_sync);
-			r_vec->rx_drops++;
-			u64_stats_update_end(&r_vec->rx_sync);
+			nfp_net_rx_drop(r_vec, rx_ring, &rx_ring->rxbufs[idx],
+					NULL);
 			continue;
 		}
 
@@ -1420,12 +1431,8 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget)
 
 			end = nfp_net_parse_meta(nn->netdev, skb, meta_len);
 			if (unlikely(end != skb->data)) {
-				u64_stats_update_begin(&r_vec->rx_sync);
-				r_vec->rx_drops++;
-				u64_stats_update_end(&r_vec->rx_sync);
-
-				dev_kfree_skb_any(skb);
 				nn_warn_ratelimit(nn, "invalid RX packet metadata\n");
+				nfp_net_rx_drop(r_vec, rx_ring, NULL, skb);
 				continue;
 			}
 		}
-- 
1.9.1

[PATCH net-next 07/14] nfp: use alloc_frag() and build_skb()

[Jakub Kicinski]

Speed up RX processing by moving to the alloc_frag()/build_skb()
paradigm.  Since we're no longer mapping the entire buffer for
DMA add helpers which take care of calculating offsets and
lengths.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
 drivers/net/ethernet/netronome/nfp/nfp_net.h       |   8 +-
 .../net/ethernet/netronome/nfp/nfp_net_common.c    | 115 +++++++++++++--------
 .../net/ethernet/netronome/nfp/nfp_net_debugfs.c   |   9 +-
 3 files changed, 82 insertions(+), 50 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net.h b/drivers/net/ethernet/netronome/nfp/nfp_net.h
index 9b90fab8a6df..9ca066b29f07 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net.h
@@ -101,6 +101,10 @@
 /* Offload definitions */
 #define NFP_NET_N_VXLAN_PORTS	(NFP_NET_CFG_VXLAN_SZ / sizeof(__be16))
 
+#define NFP_NET_RX_BUF_HEADROOM	(NET_SKB_PAD + NET_IP_ALIGN)
+#define NFP_NET_RX_BUF_NON_DATA	(NFP_NET_RX_BUF_HEADROOM +		\
+				 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
+
 /* Forward declarations */
 struct nfp_net;
 struct nfp_net_r_vector;
@@ -277,11 +281,11 @@ struct nfp_net_rx_hash {
 
 /**
  * struct nfp_net_rx_buf - software RX buffer descriptor
- * @skb:	sk_buff associated with this buffer
+ * @frag:	page fragment buffer
  * @dma_addr:	DMA mapping address of the buffer
  */
 struct nfp_net_rx_buf {
-	struct sk_buff *skb;
+	void *frag;
 	dma_addr_t dma_addr;
 };
 
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index abd4f17e89c7..449ec798a9b7 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -50,6 +50,7 @@
 #include <linux/interrupt.h>
 #include <linux/ip.h>
 #include <linux/ipv6.h>
+#include <linux/page_ref.h>
 #include <linux/pci.h>
 #include <linux/pci_regs.h>
 #include <linux/msi.h>
@@ -80,6 +81,22 @@ void nfp_net_get_fw_version(struct nfp_net_fw_version *fw_ver,
 	put_unaligned_le32(reg, fw_ver);
 }
 
+static dma_addr_t
+nfp_net_dma_map_rx(struct nfp_net *nn, void *frag, unsigned int bufsz,
+		   int direction)
+{
+	return dma_map_single(&nn->pdev->dev, frag + NFP_NET_RX_BUF_HEADROOM,
+			      bufsz - NFP_NET_RX_BUF_NON_DATA, direction);
+}
+
+static void
+nfp_net_dma_unmap_rx(struct nfp_net *nn, dma_addr_t dma_addr,
+		     unsigned int bufsz, int direction)
+{
+	dma_unmap_single(&nn->pdev->dev, dma_addr,
+			 bufsz - NFP_NET_RX_BUF_NON_DATA, direction);
+}
+
 /* Firmware reconfig
  *
  * Firmware reconfig may take a while so we have two versions of it -
@@ -1035,64 +1052,67 @@ static void nfp_net_tx_timeout(struct net_device *netdev)
 {
 	unsigned int fl_bufsz;
 
+	fl_bufsz = NFP_NET_RX_BUF_HEADROOM;
 	if (nn->rx_offset == NFP_NET_CFG_RX_OFFSET_DYNAMIC)
-		fl_bufsz = NFP_NET_MAX_PREPEND;
+		fl_bufsz += NFP_NET_MAX_PREPEND;
 	else
-		fl_bufsz = nn->rx_offset;
+		fl_bufsz += nn->rx_offset;
 	fl_bufsz += ETH_HLEN + VLAN_HLEN * 2 + mtu;
 
+	fl_bufsz = SKB_DATA_ALIGN(fl_bufsz);
+	fl_bufsz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+
 	return fl_bufsz;
 }
 
 /**
- * nfp_net_rx_alloc_one() - Allocate and map skb for RX
+ * nfp_net_rx_alloc_one() - Allocate and map page frag for RX
  * @rx_ring:	RX ring structure of the skb
  * @dma_addr:	Pointer to storage for DMA address (output param)
  * @fl_bufsz:	size of freelist buffers
  *
- * This function will allcate a new skb, map it for DMA.
+ * This function will allcate a new page frag, map it for DMA.
  *
- * Return: allocated skb or NULL on failure.
+ * Return: allocated page frag or NULL on failure.
  */
-static struct sk_buff *
+static void *
 nfp_net_rx_alloc_one(struct nfp_net_rx_ring *rx_ring, dma_addr_t *dma_addr,
 		     unsigned int fl_bufsz)
 {
 	struct nfp_net *nn = rx_ring->r_vec->nfp_net;
-	struct sk_buff *skb;
+	void *frag;
 
-	skb = netdev_alloc_skb(nn->netdev, fl_bufsz);
-	if (!skb) {
-		nn_warn_ratelimit(nn, "Failed to alloc receive SKB\n");
+	frag = netdev_alloc_frag(fl_bufsz);
+	if (!frag) {
+		nn_warn_ratelimit(nn, "Failed to alloc receive page frag\n");
 		return NULL;
 	}
 
-	*dma_addr = dma_map_single(&nn->pdev->dev, skb->data,
-				   fl_bufsz, DMA_FROM_DEVICE);
+	*dma_addr = nfp_net_dma_map_rx(nn, frag, fl_bufsz, DMA_FROM_DEVICE);
 	if (dma_mapping_error(&nn->pdev->dev, *dma_addr)) {
-		dev_kfree_skb_any(skb);
+		skb_free_frag(frag);
 		nn_warn_ratelimit(nn, "Failed to map DMA RX buffer\n");
 		return NULL;
 	}
 
-	return skb;
+	return frag;
 }
 
 /**
  * nfp_net_rx_give_one() - Put mapped skb on the software and hardware rings
  * @rx_ring:	RX ring structure
- * @skb:	Skb to put on rings
+ * @frag:	page fragment buffer
  * @dma_addr:	DMA address of skb mapping
  */
 static void nfp_net_rx_give_one(struct nfp_net_rx_ring *rx_ring,
-				struct sk_buff *skb, dma_addr_t dma_addr)
+				void *frag, dma_addr_t dma_addr)
 {
 	unsigned int wr_idx;
 
 	wr_idx = rx_ring->wr_p % rx_ring->cnt;
 
 	/* Stash SKB and DMA address away */
-	rx_ring->rxbufs[wr_idx].skb = skb;
+	rx_ring->rxbufs[wr_idx].frag = frag;
 	rx_ring->rxbufs[wr_idx].dma_addr = dma_addr;
 
 	/* Fill freelist descriptor */
@@ -1127,9 +1147,9 @@ static void nfp_net_rx_ring_reset(struct nfp_net_rx_ring *rx_ring)
 	wr_idx = rx_ring->wr_p % rx_ring->cnt;
 	last_idx = rx_ring->cnt - 1;
 	rx_ring->rxbufs[wr_idx].dma_addr = rx_ring->rxbufs[last_idx].dma_addr;
-	rx_ring->rxbufs[wr_idx].skb = rx_ring->rxbufs[last_idx].skb;
+	rx_ring->rxbufs[wr_idx].frag = rx_ring->rxbufs[last_idx].frag;
 	rx_ring->rxbufs[last_idx].dma_addr = 0;
-	rx_ring->rxbufs[last_idx].skb = NULL;
+	rx_ring->rxbufs[last_idx].frag = NULL;
 
 	memset(rx_ring->rxds, 0, sizeof(*rx_ring->rxds) * rx_ring->cnt);
 	rx_ring->wr_p = 0;
@@ -1149,7 +1169,6 @@ static void nfp_net_rx_ring_reset(struct nfp_net_rx_ring *rx_ring)
 static void
 nfp_net_rx_ring_bufs_free(struct nfp_net *nn, struct nfp_net_rx_ring *rx_ring)
 {
-	struct pci_dev *pdev = nn->pdev;
 	unsigned int i;
 
 	for (i = 0; i < rx_ring->cnt - 1; i++) {
@@ -1157,14 +1176,14 @@ static void nfp_net_rx_ring_reset(struct nfp_net_rx_ring *rx_ring)
 		 * fails to allocate enough buffers and calls here to free
 		 * already allocated ones.
 		 */
-		if (!rx_ring->rxbufs[i].skb)
+		if (!rx_ring->rxbufs[i].frag)
 			continue;
 
-		dma_unmap_single(&pdev->dev, rx_ring->rxbufs[i].dma_addr,
-				 rx_ring->bufsz, DMA_FROM_DEVICE);
-		dev_kfree_skb_any(rx_ring->rxbufs[i].skb);
+		nfp_net_dma_unmap_rx(nn, rx_ring->rxbufs[i].dma_addr,
+				     rx_ring->bufsz, DMA_FROM_DEVICE);
+		skb_free_frag(rx_ring->rxbufs[i].frag);
 		rx_ring->rxbufs[i].dma_addr = 0;
-		rx_ring->rxbufs[i].skb = NULL;
+		rx_ring->rxbufs[i].frag = NULL;
 	}
 }
 
@@ -1182,10 +1201,10 @@ static void nfp_net_rx_ring_reset(struct nfp_net_rx_ring *rx_ring)
 	rxbufs = rx_ring->rxbufs;
 
 	for (i = 0; i < rx_ring->cnt - 1; i++) {
-		rxbufs[i].skb =
+		rxbufs[i].frag =
 			nfp_net_rx_alloc_one(rx_ring, &rxbufs[i].dma_addr,
 					     rx_ring->bufsz);
-		if (!rxbufs[i].skb) {
+		if (!rxbufs[i].frag) {
 			nfp_net_rx_ring_bufs_free(nn, rx_ring);
 			return -ENOMEM;
 		}
@@ -1203,7 +1222,7 @@ static void nfp_net_rx_ring_fill_freelist(struct nfp_net_rx_ring *rx_ring)
 	unsigned int i;
 
 	for (i = 0; i < rx_ring->cnt - 1; i++)
-		nfp_net_rx_give_one(rx_ring, rx_ring->rxbufs[i].skb,
+		nfp_net_rx_give_one(rx_ring, rx_ring->rxbufs[i].frag,
 				    rx_ring->rxbufs[i].dma_addr);
 }
 
@@ -1338,8 +1357,13 @@ static void nfp_net_set_hash(struct net_device *netdev, struct sk_buff *skb,
 	r_vec->rx_drops++;
 	u64_stats_update_end(&r_vec->rx_sync);
 
+	/* skb is build based on the frag, free_skb() would free the frag
+	 * so to be able to reuse it we need an extra ref.
+	 */
+	if (skb && rxbuf && skb->head == rxbuf->frag)
+		page_ref_inc(virt_to_head_page(rxbuf->frag));
 	if (rxbuf)
-		nfp_net_rx_give_one(rx_ring, rxbuf->skb, rxbuf->dma_addr);
+		nfp_net_rx_give_one(rx_ring, rxbuf->frag, rxbuf->dma_addr);
 	if (skb)
 		dev_kfree_skb_any(skb);
 }
@@ -1360,10 +1384,12 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget)
 	struct nfp_net_r_vector *r_vec = rx_ring->r_vec;
 	struct nfp_net *nn = r_vec->nfp_net;
 	unsigned int data_len, meta_len;
-	struct sk_buff *skb, *new_skb;
+	struct nfp_net_rx_buf *rxbuf;
 	struct nfp_net_rx_desc *rxd;
 	dma_addr_t new_dma_addr;
+	struct sk_buff *skb;
 	int pkts_polled = 0;
+	void *new_frag;
 	int idx;
 
 	while (pkts_polled < budget) {
@@ -1381,21 +1407,23 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget)
 		rx_ring->rd_p++;
 		pkts_polled++;
 
-		skb = rx_ring->rxbufs[idx].skb;
-
-		new_skb = nfp_net_rx_alloc_one(rx_ring, &new_dma_addr,
-					       nn->fl_bufsz);
-		if (!new_skb) {
-			nfp_net_rx_drop(r_vec, rx_ring, &rx_ring->rxbufs[idx],
-					NULL);
+		rxbuf =	&rx_ring->rxbufs[idx];
+		skb = build_skb(rxbuf->frag, nn->fl_bufsz);
+		if (unlikely(!skb)) {
+			nfp_net_rx_drop(r_vec, rx_ring, rxbuf, NULL);
+			continue;
+		}
+		new_frag = nfp_net_rx_alloc_one(rx_ring, &new_dma_addr,
+						nn->fl_bufsz);
+		if (unlikely(!new_frag)) {
+			nfp_net_rx_drop(r_vec, rx_ring, rxbuf, skb);
 			continue;
 		}
 
-		dma_unmap_single(&nn->pdev->dev,
-				 rx_ring->rxbufs[idx].dma_addr,
-				 nn->fl_bufsz, DMA_FROM_DEVICE);
+		nfp_net_dma_unmap_rx(nn, rx_ring->rxbufs[idx].dma_addr,
+				     nn->fl_bufsz, DMA_FROM_DEVICE);
 
-		nfp_net_rx_give_one(rx_ring, new_skb, new_dma_addr);
+		nfp_net_rx_give_one(rx_ring, new_frag, new_dma_addr);
 
 		/*         < meta_len >
 		 *  <-- [rx_offset] -->
@@ -1413,9 +1441,10 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget)
 		data_len = le16_to_cpu(rxd->rxd.data_len);
 
 		if (nn->rx_offset == NFP_NET_CFG_RX_OFFSET_DYNAMIC)
-			skb_reserve(skb, meta_len);
+			skb_reserve(skb, NFP_NET_RX_BUF_HEADROOM + meta_len);
 		else
-			skb_reserve(skb, nn->rx_offset);
+			skb_reserve(skb,
+				    NFP_NET_RX_BUF_HEADROOM + nn->rx_offset);
 		skb_put(skb, data_len - meta_len);
 
 		/* Stats update */
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_debugfs.c b/drivers/net/ethernet/netronome/nfp/nfp_net_debugfs.c
index f7c9a5bc4aa3..180cf70f0093 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_debugfs.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_debugfs.c
@@ -44,8 +44,8 @@ static int nfp_net_debugfs_rx_q_read(struct seq_file *file, void *data)
 	struct nfp_net_r_vector *r_vec = file->private;
 	struct nfp_net_rx_ring *rx_ring;
 	struct nfp_net_rx_desc *rxd;
-	struct sk_buff *skb;
 	struct nfp_net *nn;
+	void *frag;
 	int i;
 
 	rtnl_lock();
@@ -73,10 +73,9 @@ static int nfp_net_debugfs_rx_q_read(struct seq_file *file, void *data)
 		seq_printf(file, "%04d: 0x%08x 0x%08x", i,
 			   rxd->vals[0], rxd->vals[1]);
 
-		skb = READ_ONCE(rx_ring->rxbufs[i].skb);
-		if (skb)
-			seq_printf(file, " skb->head=%p skb->data=%p",
-				   skb->head, skb->data);
+		frag = READ_ONCE(rx_ring->rxbufs[i].frag);
+		if (frag)
+			seq_printf(file, " frag=%p", frag);
 
 		if (rx_ring->rxbufs[i].dma_addr)
 			seq_printf(file, " dma_addr=%pad",
-- 
1.9.1

[PATCH net-next 08/14] nfp: add separate buffer allocation function for napi

[Jakub Kicinski]

Introduce a separate buffer allocation function to be called
from NAPI.  We can make assumptions about the context and
buffer size.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
 .../net/ethernet/netronome/nfp/nfp_net_common.c    | 23 ++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index 449ec798a9b7..b43d2dbae368 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -1098,6 +1098,26 @@ static void nfp_net_tx_timeout(struct net_device *netdev)
 	return frag;
 }
 
+static void *nfp_net_napi_alloc_one(struct nfp_net *nn, dma_addr_t *dma_addr)
+{
+	void *frag;
+
+	frag = napi_alloc_frag(nn->fl_bufsz);
+	if (!frag) {
+		nn_warn_ratelimit(nn, "Failed to alloc receive page frag\n");
+		return NULL;
+	}
+
+	*dma_addr = nfp_net_dma_map_rx(nn, frag, nn->fl_bufsz, DMA_FROM_DEVICE);
+	if (dma_mapping_error(&nn->pdev->dev, *dma_addr)) {
+		skb_free_frag(frag);
+		nn_warn_ratelimit(nn, "Failed to map DMA RX buffer\n");
+		return NULL;
+	}
+
+	return frag;
+}
+
 /**
  * nfp_net_rx_give_one() - Put mapped skb on the software and hardware rings
  * @rx_ring:	RX ring structure
@@ -1413,8 +1433,7 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget)
 			nfp_net_rx_drop(r_vec, rx_ring, rxbuf, NULL);
 			continue;
 		}
-		new_frag = nfp_net_rx_alloc_one(rx_ring, &new_dma_addr,
-						nn->fl_bufsz);
+		new_frag = nfp_net_napi_alloc_one(nn, &new_dma_addr);
 		if (unlikely(!new_frag)) {
 			nfp_net_rx_drop(r_vec, rx_ring, rxbuf, skb);
 			continue;
-- 
1.9.1

[PATCH net-next 09/14] nfp: use AND instead of modulo to get ring indexes

[Jakub Kicinski]

We already force ring sizes to be power of 2 so replace
modulo operations with AND (size - 1) in index calculations.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
 drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index b43d2dbae368..7225ab61a120 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -778,7 +778,7 @@ static int nfp_net_tx(struct sk_buff *skb, struct net_device *netdev)
 	if (dma_mapping_error(&nn->pdev->dev, dma_addr))
 		goto err_free;
 
-	wr_idx = tx_ring->wr_p % tx_ring->cnt;
+	wr_idx = tx_ring->wr_p & (tx_ring->cnt - 1);
 
 	/* Stash the soft descriptor of the head then initialize it */
 	txbuf = &tx_ring->txbufs[wr_idx];
@@ -822,7 +822,7 @@ static int nfp_net_tx(struct sk_buff *skb, struct net_device *netdev)
 			if (dma_mapping_error(&nn->pdev->dev, dma_addr))
 				goto err_unmap;
 
-			wr_idx = (wr_idx + 1) % tx_ring->cnt;
+			wr_idx = (wr_idx + 1) & (tx_ring->cnt - 1);
 			tx_ring->txbufs[wr_idx].skb = skb;
 			tx_ring->txbufs[wr_idx].dma_addr = dma_addr;
 			tx_ring->txbufs[wr_idx].fidx = f;
@@ -917,7 +917,7 @@ static void nfp_net_tx_complete(struct nfp_net_tx_ring *tx_ring)
 		todo = qcp_rd_p + tx_ring->cnt - tx_ring->qcp_rd_p;
 
 	while (todo--) {
-		idx = tx_ring->rd_p % tx_ring->cnt;
+		idx = tx_ring->rd_p & (tx_ring->cnt - 1);
 		tx_ring->rd_p++;
 
 		skb = tx_ring->txbufs[idx].skb;
@@ -992,7 +992,7 @@ static void nfp_net_tx_complete(struct nfp_net_tx_ring *tx_ring)
 		int nr_frags, fidx, idx;
 		struct sk_buff *skb;
 
-		idx = tx_ring->rd_p % tx_ring->cnt;
+		idx = tx_ring->rd_p & (tx_ring->cnt - 1);
 		skb = tx_ring->txbufs[idx].skb;
 		nr_frags = skb_shinfo(skb)->nr_frags;
 		fidx = tx_ring->txbufs[idx].fidx;
@@ -1129,7 +1129,7 @@ static void nfp_net_rx_give_one(struct nfp_net_rx_ring *rx_ring,
 {
 	unsigned int wr_idx;
 
-	wr_idx = rx_ring->wr_p % rx_ring->cnt;
+	wr_idx = rx_ring->wr_p & (rx_ring->cnt - 1);
 
 	/* Stash SKB and DMA address away */
 	rx_ring->rxbufs[wr_idx].frag = frag;
@@ -1164,7 +1164,7 @@ static void nfp_net_rx_ring_reset(struct nfp_net_rx_ring *rx_ring)
 	unsigned int wr_idx, last_idx;
 
 	/* Move the empty entry to the end of the list */
-	wr_idx = rx_ring->wr_p % rx_ring->cnt;
+	wr_idx = rx_ring->wr_p & (rx_ring->cnt - 1);
 	last_idx = rx_ring->cnt - 1;
 	rx_ring->rxbufs[wr_idx].dma_addr = rx_ring->rxbufs[last_idx].dma_addr;
 	rx_ring->rxbufs[wr_idx].frag = rx_ring->rxbufs[last_idx].frag;
@@ -1413,7 +1413,7 @@ static int nfp_net_rx(struct nfp_net_rx_ring *rx_ring, int budget)
 	int idx;
 
 	while (pkts_polled < budget) {
-		idx = rx_ring->rd_p % rx_ring->cnt;
+		idx = rx_ring->rd_p & (rx_ring->cnt - 1);
 
 		rxd = &rx_ring->rxds[idx];
 		if (!(rxd->rxd.meta_len_dd & PCIE_DESC_RX_DD))
-- 
1.9.1

[PATCH net-next 10/14] nfp: create separate define for max number of vectors

[Jakub Kicinski]

We are currently using define for max TX rings to allocate IRQ
vectors.  It's OK since the max number of rings for TX and RX
are currently the same, but lets make the code nicer by taking
max of the two.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
 drivers/net/ethernet/netronome/nfp/nfp_net.h | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net.h b/drivers/net/ethernet/netronome/nfp/nfp_net.h
index 9ca066b29f07..55a497c02237 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net.h
@@ -87,6 +87,9 @@
 /* Queue/Ring definitions */
 #define NFP_NET_MAX_TX_RINGS	64	/* Max. # of Tx rings per device */
 #define NFP_NET_MAX_RX_RINGS	64	/* Max. # of Rx rings per device */
+#define NFP_NET_MAX_R_VECS	(NFP_NET_MAX_TX_RINGS > NFP_NET_MAX_RX_RINGS ? \
+				 NFP_NET_MAX_TX_RINGS : NFP_NET_MAX_RX_RINGS)
+#define NFP_NET_MAX_IRQS	(NFP_NET_NON_Q_VECTORS + NFP_NET_MAX_R_VECS)
 
 #define NFP_NET_MIN_TX_DESCS	256	/* Min. # of Tx descs per ring */
 #define NFP_NET_MIN_RX_DESCS	256	/* Min. # of Rx descs per ring */
@@ -539,9 +542,8 @@ struct nfp_net {
 
 	u8 num_irqs;
 	u8 num_r_vecs;
-	struct nfp_net_r_vector r_vecs[NFP_NET_MAX_TX_RINGS];
-	struct msix_entry irq_entries[NFP_NET_NON_Q_VECTORS +
-				      NFP_NET_MAX_TX_RINGS];
+	struct nfp_net_r_vector r_vecs[NFP_NET_MAX_R_VECS];
+	struct msix_entry irq_entries[NFP_NET_MAX_IRQS];
 
 	irq_handler_t lsc_handler;
 	char lsc_name[IFNAMSIZ + 8];
-- 
1.9.1

[PATCH net-next 11/14] nfp: use unsigned int for vector/ring counts

[Jakub Kicinski]

Use unsigned int consistently for vector/ring counts.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
 drivers/net/ethernet/netronome/nfp/nfp_net.h        | 17 +++++++++--------
 drivers/net/ethernet/netronome/nfp/nfp_net_common.c |  5 +++--
 2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net.h b/drivers/net/ethernet/netronome/nfp/nfp_net.h
index 55a497c02237..0ea6ebd329cf 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net.h
@@ -528,11 +528,11 @@ struct nfp_net {
 	struct timer_list rx_filter_stats_timer;
 	spinlock_t rx_filter_lock;
 
-	int max_tx_rings;
-	int max_rx_rings;
+	unsigned int max_tx_rings;
+	unsigned int max_rx_rings;
 
-	int num_tx_rings;
-	int num_rx_rings;
+	unsigned int num_tx_rings;
+	unsigned int num_rx_rings;
 
 	int stride_tx;
 	int stride_rx;
@@ -540,8 +540,8 @@ struct nfp_net {
 	int txd_cnt;
 	int rxd_cnt;
 
-	u8 num_irqs;
-	u8 num_r_vecs;
+	unsigned int num_irqs;
+	unsigned int num_r_vecs;
 	struct nfp_net_r_vector r_vecs[NFP_NET_MAX_R_VECS];
 	struct msix_entry irq_entries[NFP_NET_MAX_IRQS];
 
@@ -757,8 +757,9 @@ static inline u32 nfp_qcp_wr_ptr_read(u8 __iomem *q)
 void nfp_net_get_fw_version(struct nfp_net_fw_version *fw_ver,
 			    void __iomem *ctrl_bar);
 
-struct nfp_net *nfp_net_netdev_alloc(struct pci_dev *pdev,
-				     int max_tx_rings, int max_rx_rings);
+struct nfp_net *
+nfp_net_netdev_alloc(struct pci_dev *pdev,
+		     unsigned int max_tx_rings, unsigned int max_rx_rings);
 void nfp_net_netdev_free(struct nfp_net *nn);
 int nfp_net_netdev_init(struct net_device *netdev);
 void nfp_net_netdev_clean(struct net_device *netdev);
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index 7225ab61a120..49a1f54e0787 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -318,8 +318,8 @@ static int nfp_net_msix_alloc(struct nfp_net *nn, int nr_vecs)
  */
 static int nfp_net_irqs_wanted(struct nfp_net *nn)
 {
+	unsigned int vecs;
 	int ncpus;
-	int vecs;
 
 	ncpus = num_online_cpus();
 
@@ -2701,7 +2701,8 @@ void nfp_net_info(struct nfp_net *nn)
  * Return: NFP Net device structure, or ERR_PTR on error.
  */
 struct nfp_net *nfp_net_netdev_alloc(struct pci_dev *pdev,
-				     int max_tx_rings, int max_rx_rings)
+				     unsigned int max_tx_rings,
+				     unsigned int max_rx_rings)
 {
 	struct net_device *netdev;
 	struct nfp_net *nn;
-- 
1.9.1

[PATCH net-next 12/14] nfp: remove nfp_net_irqs_wanted()

[Jakub Kicinski]

nfp_net_irqs_wanted() doesn't really encapsulate much logic,
remove it and inline the calculations.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
 .../net/ethernet/netronome/nfp/nfp_net_common.c    | 27 ++++------------------
 1 file changed, 4 insertions(+), 23 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index 49a1f54e0787..f26c3927746f 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -308,28 +308,6 @@ static int nfp_net_msix_alloc(struct nfp_net *nn, int nr_vecs)
 }
 
 /**
- * nfp_net_irqs_wanted() - Work out how many interrupt vectors we want
- * @nn:       NFP Network structure
- *
- * We want a vector per CPU (or ring), whatever is smaller plus
- * NFP_NET_NON_Q_VECTORS for LSC etc.
- *
- * Return: Number of interrupts wanted
- */
-static int nfp_net_irqs_wanted(struct nfp_net *nn)
-{
-	unsigned int vecs;
-	int ncpus;
-
-	ncpus = num_online_cpus();
-
-	vecs = max_t(int, nn->num_tx_rings, nn->num_rx_rings);
-	vecs = min_t(int, vecs, ncpus);
-
-	return vecs + NFP_NET_NON_Q_VECTORS;
-}
-
-/**
  * nfp_net_irqs_alloc() - allocates MSI-X irqs
  * @nn:       NFP Network structure
  *
@@ -339,7 +317,7 @@ int nfp_net_irqs_alloc(struct nfp_net *nn)
 {
 	int wanted_irqs;
 
-	wanted_irqs = nfp_net_irqs_wanted(nn);
+	wanted_irqs = nn->num_r_vecs + NFP_NET_NON_Q_VECTORS;
 
 	nn->num_irqs = nfp_net_msix_alloc(nn, wanted_irqs);
 	if (nn->num_irqs == 0) {
@@ -2726,6 +2704,9 @@ struct nfp_net *nfp_net_netdev_alloc(struct pci_dev *pdev,
 	nn->num_tx_rings = min_t(int, nqs, max_tx_rings);
 	nn->num_rx_rings = min_t(int, nqs, max_rx_rings);
 
+	nn->num_r_vecs = max(nn->num_tx_rings, nn->num_rx_rings);
+	nn->num_r_vecs = min_t(unsigned int, nn->num_r_vecs, num_online_cpus());
+
 	nn->txd_cnt = NFP_NET_TX_DESCS_DEFAULT;
 	nn->rxd_cnt = NFP_NET_RX_DESCS_DEFAULT;
 
-- 
1.9.1

[PATCH net-next 13/14] nfp: replace num_irqs with max_r_vecs

[Jakub Kicinski]

num_irqs is not used anywhere, replace it with max_r_vecs which holds
number of allocated RX/TX vectors and is going to be useful soon.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
 drivers/net/ethernet/netronome/nfp/nfp_net.h        |  4 ++--
 drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 14 ++++++++------
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net.h b/drivers/net/ethernet/netronome/nfp/nfp_net.h
index 0ea6ebd329cf..e8713254786b 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net.h
@@ -456,7 +456,7 @@ struct nfp_stat_pair {
  * @rxd_cnt:            Size of the RX ring in number of descriptors
  * @tx_rings:           Array of pre-allocated TX ring structures
  * @rx_rings:           Array of pre-allocated RX ring structures
- * @num_irqs:	        Number of allocated interrupt vectors
+ * @max_r_vecs:	        Number of allocated interrupt vectors for RX/TX
  * @num_r_vecs:         Number of used ring vectors
  * @r_vecs:             Pre-allocated array of ring vectors
  * @irq_entries:        Pre-allocated array of MSI-X entries
@@ -540,7 +540,7 @@ struct nfp_net {
 	int txd_cnt;
 	int rxd_cnt;
 
-	unsigned int num_irqs;
+	unsigned int max_r_vecs;
 	unsigned int num_r_vecs;
 	struct nfp_net_r_vector r_vecs[NFP_NET_MAX_R_VECS];
 	struct msix_entry irq_entries[NFP_NET_MAX_IRQS];
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index f26c3927746f..4b866fc874b6 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -316,22 +316,24 @@ static int nfp_net_msix_alloc(struct nfp_net *nn, int nr_vecs)
 int nfp_net_irqs_alloc(struct nfp_net *nn)
 {
 	int wanted_irqs;
+	unsigned int n;
 
 	wanted_irqs = nn->num_r_vecs + NFP_NET_NON_Q_VECTORS;
 
-	nn->num_irqs = nfp_net_msix_alloc(nn, wanted_irqs);
-	if (nn->num_irqs == 0) {
+	n = nfp_net_msix_alloc(nn, wanted_irqs);
+	if (n == 0) {
 		nn_err(nn, "Failed to allocate MSI-X IRQs\n");
 		return 0;
 	}
 
-	nn->num_r_vecs = nn->num_irqs - NFP_NET_NON_Q_VECTORS;
+	nn->max_r_vecs = n - NFP_NET_NON_Q_VECTORS;
+	nn->num_r_vecs = nn->max_r_vecs;
 
-	if (nn->num_irqs < wanted_irqs)
+	if (n < wanted_irqs)
 		nn_warn(nn, "Unable to allocate %d vectors. Got %d instead\n",
-			wanted_irqs, nn->num_irqs);
+			wanted_irqs, n);
 
-	return nn->num_irqs;
+	return n;
 }
 
 /**
-- 
1.9.1

[PATCH net-next 14/14] nfp: bring back support for different ring counts

[Jakub Kicinski]

We used to always allocate the same number of TX and RX rings
so the support for having r_vectors without one of the rings
was dropped.  That makes us, however, unnecessarily limited
to 8 TX rings (8 is the Linux RSS default) most of the time.
Also we are about to add channel count configuration via
ethtool, so bring that support back.  TX rings can now default
to num_online_cpus() and RX rings to netif_get_num_default_rss_queues().

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
 .../net/ethernet/netronome/nfp/nfp_net_common.c    | 118 +++++++++++++--------
 1 file changed, 71 insertions(+), 47 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index 4b866fc874b6..97e0bbef13d1 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -483,13 +483,13 @@ static void nfp_net_irqs_assign(struct net_device *netdev)
 	struct nfp_net_r_vector *r_vec;
 	int r;
 
-	/* Assumes nn->num_tx_rings == nn->num_rx_rings */
-	if (nn->num_tx_rings > nn->num_r_vecs) {
-		nn_warn(nn, "More rings (%d) than vectors (%d).\n",
-			nn->num_tx_rings, nn->num_r_vecs);
-		nn->num_tx_rings = nn->num_r_vecs;
-		nn->num_rx_rings = nn->num_r_vecs;
-	}
+	if (nn->num_rx_rings > nn->num_r_vecs ||
+	    nn->num_tx_rings > nn->num_r_vecs)
+		nn_warn(nn, "More rings (%d,%d) than vectors (%d).\n",
+			nn->num_rx_rings, nn->num_tx_rings, nn->num_r_vecs);
+
+	nn->num_rx_rings = min(nn->num_r_vecs, nn->num_rx_rings);
+	nn->num_tx_rings = min(nn->num_r_vecs, nn->num_tx_rings);
 
 	nn->lsc_handler = nfp_net_irq_lsc;
 	nn->exn_handler = nfp_net_irq_exn;
@@ -1491,11 +1491,12 @@ static int nfp_net_poll(struct napi_struct *napi, int budget)
 {
 	struct nfp_net_r_vector *r_vec =
 		container_of(napi, struct nfp_net_r_vector, napi);
-	unsigned int pkts_polled;
-
-	nfp_net_tx_complete(r_vec->tx_ring);
+	unsigned int pkts_polled = 0;
 
-	pkts_polled = nfp_net_rx(r_vec->rx_ring, budget);
+	if (r_vec->tx_ring)
+		nfp_net_tx_complete(r_vec->tx_ring);
+	if (r_vec->rx_ring)
+		pkts_polled = nfp_net_rx(r_vec->rx_ring, budget);
 
 	if (pkts_polled < budget) {
 		napi_complete_done(napi, pkts_polled);
@@ -1743,7 +1744,7 @@ static void nfp_net_rx_ring_free(struct nfp_net_rx_ring *rx_ring)
 	if (!rings)
 		return;
 
-	for (r = 0; r < nn->num_r_vecs; r++) {
+	for (r = 0; r < nn->num_rx_rings; r++) {
 		nfp_net_rx_ring_bufs_free(nn, &rings[r]);
 		nfp_net_rx_ring_free(&rings[r]);
 	}
@@ -1758,11 +1759,19 @@ static void nfp_net_rx_ring_free(struct nfp_net_rx_ring *rx_ring)
 	struct msix_entry *entry = &nn->irq_entries[r_vec->irq_idx];
 	int err;
 
-	r_vec->tx_ring = &nn->tx_rings[idx];
-	nfp_net_tx_ring_init(r_vec->tx_ring, r_vec, idx);
+	if (idx < nn->num_tx_rings) {
+		r_vec->tx_ring = &nn->tx_rings[idx];
+		nfp_net_tx_ring_init(r_vec->tx_ring, r_vec, idx);
+	} else {
+		r_vec->tx_ring = NULL;
+	}
 
-	r_vec->rx_ring = &nn->rx_rings[idx];
-	nfp_net_rx_ring_init(r_vec->rx_ring, r_vec, idx);
+	if (idx < nn->num_rx_rings) {
+		r_vec->rx_ring = &nn->rx_rings[idx];
+		nfp_net_rx_ring_init(r_vec->rx_ring, r_vec, idx);
+	} else {
+		r_vec->rx_ring = NULL;
+	}
 
 	snprintf(r_vec->name, sizeof(r_vec->name),
 		 "%s-rxtx-%d", nn->netdev->name, idx);
@@ -1839,13 +1848,13 @@ void nfp_net_coalesce_write_cfg(struct nfp_net *nn)
 	/* copy RX interrupt coalesce parameters */
 	value = (nn->rx_coalesce_max_frames << 16) |
 		(factor * nn->rx_coalesce_usecs);
-	for (i = 0; i < nn->num_r_vecs; i++)
+	for (i = 0; i < nn->num_rx_rings; i++)
 		nn_writel(nn, NFP_NET_CFG_RXR_IRQ_MOD(i), value);
 
 	/* copy TX interrupt coalesce parameters */
 	value = (nn->tx_coalesce_max_frames << 16) |
 		(factor * nn->tx_coalesce_usecs);
-	for (i = 0; i < nn->num_r_vecs; i++)
+	for (i = 0; i < nn->num_tx_rings; i++)
 		nn_writel(nn, NFP_NET_CFG_TXR_IRQ_MOD(i), value);
 }
 
@@ -1903,27 +1912,33 @@ static void nfp_net_clear_config_and_disable(struct nfp_net *nn)
 	if (err)
 		nn_err(nn, "Could not disable device: %d\n", err);
 
-	for (r = 0; r < nn->num_r_vecs; r++) {
+	for (r = 0; r < nn->num_rx_rings; r++)
 		nfp_net_rx_ring_reset(nn->r_vecs[r].rx_ring);
+	for (r = 0; r < nn->num_tx_rings; r++)
 		nfp_net_tx_ring_reset(nn, nn->r_vecs[r].tx_ring);
+	for (r = 0; r < nn->num_r_vecs; r++)
 		nfp_net_vec_clear_ring_data(nn, r);
-	}
 
 	nn->ctrl = new_ctrl;
 }
 
 static void
-nfp_net_vec_write_ring_data(struct nfp_net *nn, struct nfp_net_r_vector *r_vec,
-			    unsigned int idx)
+nfp_net_rx_ring_hw_cfg_write(struct nfp_net *nn,
+			     struct nfp_net_rx_ring *rx_ring, unsigned int idx)
 {
 	/* Write the DMA address, size and MSI-X info to the device */
-	nn_writeq(nn, NFP_NET_CFG_RXR_ADDR(idx), r_vec->rx_ring->dma);
-	nn_writeb(nn, NFP_NET_CFG_RXR_SZ(idx), ilog2(r_vec->rx_ring->cnt));
-	nn_writeb(nn, NFP_NET_CFG_RXR_VEC(idx), r_vec->irq_idx);
+	nn_writeq(nn, NFP_NET_CFG_RXR_ADDR(idx), rx_ring->dma);
+	nn_writeb(nn, NFP_NET_CFG_RXR_SZ(idx), ilog2(rx_ring->cnt));
+	nn_writeb(nn, NFP_NET_CFG_RXR_VEC(idx), rx_ring->r_vec->irq_idx);
+}
 
-	nn_writeq(nn, NFP_NET_CFG_TXR_ADDR(idx), r_vec->tx_ring->dma);
-	nn_writeb(nn, NFP_NET_CFG_TXR_SZ(idx), ilog2(r_vec->tx_ring->cnt));
-	nn_writeb(nn, NFP_NET_CFG_TXR_VEC(idx), r_vec->irq_idx);
+static void
+nfp_net_tx_ring_hw_cfg_write(struct nfp_net *nn,
+			     struct nfp_net_tx_ring *tx_ring, unsigned int idx)
+{
+	nn_writeq(nn, NFP_NET_CFG_TXR_ADDR(idx), tx_ring->dma);
+	nn_writeb(nn, NFP_NET_CFG_TXR_SZ(idx), ilog2(tx_ring->cnt));
+	nn_writeb(nn, NFP_NET_CFG_TXR_VEC(idx), tx_ring->r_vec->irq_idx);
 }
 
 static int __nfp_net_set_config_and_enable(struct nfp_net *nn)
@@ -1948,8 +1963,10 @@ static int __nfp_net_set_config_and_enable(struct nfp_net *nn)
 		update |= NFP_NET_CFG_UPDATE_IRQMOD;
 	}
 
-	for (r = 0; r < nn->num_r_vecs; r++)
-		nfp_net_vec_write_ring_data(nn, &nn->r_vecs[r], r);
+	for (r = 0; r < nn->num_tx_rings; r++)
+		nfp_net_tx_ring_hw_cfg_write(nn, &nn->tx_rings[r], r);
+	for (r = 0; r < nn->num_rx_rings; r++)
+		nfp_net_rx_ring_hw_cfg_write(nn, &nn->rx_rings[r], r);
 
 	nn_writeq(nn, NFP_NET_CFG_TXRS_ENABLE, nn->num_tx_rings == 64 ?
 		  0xffffffffffffffffULL : ((u64)1 << nn->num_tx_rings) - 1);
@@ -1975,7 +1992,7 @@ static int __nfp_net_set_config_and_enable(struct nfp_net *nn)
 
 	nn->ctrl = new_ctrl;
 
-	for (r = 0; r < nn->num_r_vecs; r++)
+	for (r = 0; r < nn->num_rx_rings; r++)
 		nfp_net_rx_ring_fill_freelist(nn->r_vecs[r].rx_ring);
 
 	/* Since reconfiguration requests while NFP is down are ignored we
@@ -2067,20 +2084,22 @@ static int nfp_net_netdev_open(struct net_device *netdev)
 	for (r = 0; r < nn->num_r_vecs; r++) {
 		err = nfp_net_prepare_vector(nn, &nn->r_vecs[r], r);
 		if (err)
-			goto err_free_prev_vecs;
-
+			goto err_cleanup_vec_p;
+	}
+	for (r = 0; r < nn->num_tx_rings; r++) {
 		err = nfp_net_tx_ring_alloc(nn->r_vecs[r].tx_ring, nn->txd_cnt);
 		if (err)
-			goto err_cleanup_vec_p;
-
+			goto err_free_tx_ring_p;
+	}
+	for (r = 0; r < nn->num_rx_rings; r++) {
 		err = nfp_net_rx_ring_alloc(nn->r_vecs[r].rx_ring,
 					    nn->fl_bufsz, nn->rxd_cnt);
 		if (err)
-			goto err_free_tx_ring_p;
+			goto err_flush_free_rx_ring_p;
 
 		err = nfp_net_rx_ring_bufs_alloc(nn, nn->r_vecs[r].rx_ring);
 		if (err)
-			goto err_flush_rx_ring_p;
+			goto err_free_rx_ring_p;
 	}
 
 	err = netif_set_real_num_tx_queues(netdev, nn->num_tx_rings);
@@ -2113,17 +2132,21 @@ static int nfp_net_netdev_open(struct net_device *netdev)
 	return 0;
 
 err_free_rings:
-	r = nn->num_r_vecs;
-err_free_prev_vecs:
+	r = nn->num_rx_rings;
+err_flush_free_rx_ring_p:
 	while (r--) {
 		nfp_net_rx_ring_bufs_free(nn, nn->r_vecs[r].rx_ring);
-err_flush_rx_ring_p:
+err_free_rx_ring_p:
 		nfp_net_rx_ring_free(nn->r_vecs[r].rx_ring);
+	}
+	r = nn->num_tx_rings;
 err_free_tx_ring_p:
+	while (r--)
 		nfp_net_tx_ring_free(nn->r_vecs[r].tx_ring);
+	r = nn->num_r_vecs;
 err_cleanup_vec_p:
+	while (r--)
 		nfp_net_cleanup_vector(nn, &nn->r_vecs[r]);
-	}
 	kfree(nn->tx_rings);
 err_free_rx_rings:
 	kfree(nn->rx_rings);
@@ -2162,12 +2185,14 @@ static void nfp_net_close_free_all(struct nfp_net *nn)
 {
 	unsigned int r;
 
-	for (r = 0; r < nn->num_r_vecs; r++) {
+	for (r = 0; r < nn->num_rx_rings; r++) {
 		nfp_net_rx_ring_bufs_free(nn, nn->r_vecs[r].rx_ring);
 		nfp_net_rx_ring_free(nn->r_vecs[r].rx_ring);
+	}
+	for (r = 0; r < nn->num_tx_rings; r++)
 		nfp_net_tx_ring_free(nn->r_vecs[r].tx_ring);
+	for (r = 0; r < nn->num_r_vecs; r++)
 		nfp_net_cleanup_vector(nn, &nn->r_vecs[r]);
-	}
 
 	kfree(nn->rx_rings);
 	kfree(nn->tx_rings);
@@ -2686,7 +2711,6 @@ struct nfp_net *nfp_net_netdev_alloc(struct pci_dev *pdev,
 {
 	struct net_device *netdev;
 	struct nfp_net *nn;
-	int nqs;
 
 	netdev = alloc_etherdev_mqs(sizeof(struct nfp_net),
 				    max_tx_rings, max_rx_rings);
@@ -2702,9 +2726,9 @@ struct nfp_net *nfp_net_netdev_alloc(struct pci_dev *pdev,
 	nn->max_tx_rings = max_tx_rings;
 	nn->max_rx_rings = max_rx_rings;
 
-	nqs = netif_get_num_default_rss_queues();
-	nn->num_tx_rings = min_t(int, nqs, max_tx_rings);
-	nn->num_rx_rings = min_t(int, nqs, max_rx_rings);
+	nn->num_tx_rings = min_t(unsigned int, max_tx_rings, num_online_cpus());
+	nn->num_rx_rings = min_t(unsigned int, max_rx_rings,
+				 netif_get_num_default_rss_queues());
 
 	nn->num_r_vecs = max(nn->num_tx_rings, nn->num_rx_rings);
 	nn->num_r_vecs = min_t(unsigned int, nn->num_r_vecs, num_online_cpus());
-- 
1.9.1

Re: [PATCH net-next 00/14] cleanups and RX path rewrite

[David Miller]

From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Mon, 31 Oct 2016 20:43:08 +0000

> This series lays groundwork for upcoming XDP support by updating
> the RX path not to pre-allocate sk_buffs.  I start with few
> cleanups, removal of NFP3200-related code being the most significant.
> Patch 7 moves to alloc_frag() and build_skb() APIs.  Again, a number
> of small cleanups follow.  The set ends with adding support for
> different number of RX and TX rings.

Series applied, thank you.