1 files changed, 484 insertions, 0 deletions

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
new file mode 100644
index 000000000..aa56db138
--- /dev/null
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
@@ -0,0 +1,484 @@
+/* Broadcom NetXtreme-C/E network driver.
+ *
+ * Copyright (c) 2016-2017 Broadcom Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/pci.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/if_vlan.h>
+#include <linux/bpf.h>
+#include <linux/bpf_trace.h>
+#include <linux/filter.h>
+#include <net/page_pool.h>
+#include "bnxt_hsi.h"
+#include "bnxt.h"
+#include "bnxt_xdp.h"
+
+DEFINE_STATIC_KEY_FALSE(bnxt_xdp_locking_key);
+
+struct bnxt_sw_tx_bd *bnxt_xmit_bd(struct bnxt *bp,
+				   struct bnxt_tx_ring_info *txr,
+				   dma_addr_t mapping, u32 len,
+				   struct xdp_buff *xdp)
+{
+	struct skb_shared_info *sinfo;
+	struct bnxt_sw_tx_bd *tx_buf;
+	struct tx_bd *txbd;
+	int num_frags = 0;
+	u32 flags;
+	u16 prod;
+	int i;
+
+	if (xdp && xdp_buff_has_frags(xdp)) {
+		sinfo = xdp_get_shared_info_from_buff(xdp);
+		num_frags = sinfo->nr_frags;
+	}
+
+	/* fill up the first buffer */
+	prod = txr->tx_prod;
+	tx_buf = &txr->tx_buf_ring[prod];
+	tx_buf->nr_frags = num_frags;
+	if (xdp)
+		tx_buf->page = virt_to_head_page(xdp->data);
+
+	txbd = &txr->tx_desc_ring[TX_RING(prod)][TX_IDX(prod)];
+	flags = (len << TX_BD_LEN_SHIFT) |
+		((num_frags + 1) << TX_BD_FLAGS_BD_CNT_SHIFT) |
+		bnxt_lhint_arr[len >> 9];
+	txbd->tx_bd_len_flags_type = cpu_to_le32(flags);
+	txbd->tx_bd_opaque = prod;
+	txbd->tx_bd_haddr = cpu_to_le64(mapping);
+
+	/* now let us fill up the frags into the next buffers */
+	for (i = 0; i < num_frags ; i++) {
+		skb_frag_t *frag = &sinfo->frags[i];
+		struct bnxt_sw_tx_bd *frag_tx_buf;
+		struct pci_dev *pdev = bp->pdev;
+		dma_addr_t frag_mapping;
+		int frag_len;
+
+		prod = NEXT_TX(prod);
+		txr->tx_prod = prod;
+
+		/* first fill up the first buffer */
+		frag_tx_buf = &txr->tx_buf_ring[prod];
+		frag_tx_buf->page = skb_frag_page(frag);
+
+		txbd = &txr->tx_desc_ring[TX_RING(prod)][TX_IDX(prod)];
+
+		frag_len = skb_frag_size(frag);
+		frag_mapping = skb_frag_dma_map(&pdev->dev, frag, 0,
+						frag_len, DMA_TO_DEVICE);
+
+		if (unlikely(dma_mapping_error(&pdev->dev, frag_mapping)))
+			return NULL;
+
+		dma_unmap_addr_set(frag_tx_buf, mapping, frag_mapping);
+
+		flags = frag_len << TX_BD_LEN_SHIFT;
+		txbd->tx_bd_len_flags_type = cpu_to_le32(flags);
+		txbd->tx_bd_haddr = cpu_to_le64(frag_mapping);
+
+		len = frag_len;
+	}
+
+	flags &= ~TX_BD_LEN;
+	txbd->tx_bd_len_flags_type = cpu_to_le32(((len) << TX_BD_LEN_SHIFT) | flags |
+			TX_BD_FLAGS_PACKET_END);
+	/* Sync TX BD */
+	wmb();
+	prod = NEXT_TX(prod);
+	txr->tx_prod = prod;
+
+	return tx_buf;
+}
+
+static void __bnxt_xmit_xdp(struct bnxt *bp, struct bnxt_tx_ring_info *txr,
+			    dma_addr_t mapping, u32 len, u16 rx_prod,
+			    struct xdp_buff *xdp)
+{
+	struct bnxt_sw_tx_bd *tx_buf;
+
+	tx_buf = bnxt_xmit_bd(bp, txr, mapping, len, xdp);
+	tx_buf->rx_prod = rx_prod;
+	tx_buf->action = XDP_TX;
+
+}
+
+static void __bnxt_xmit_xdp_redirect(struct bnxt *bp,
+				     struct bnxt_tx_ring_info *txr,
+				     dma_addr_t mapping, u32 len,
+				     struct xdp_frame *xdpf)
+{
+	struct bnxt_sw_tx_bd *tx_buf;
+
+	tx_buf = bnxt_xmit_bd(bp, txr, mapping, len, NULL);
+	tx_buf->action = XDP_REDIRECT;
+	tx_buf->xdpf = xdpf;
+	dma_unmap_addr_set(tx_buf, mapping, mapping);
+	dma_unmap_len_set(tx_buf, len, 0);
+}
+
+void bnxt_tx_int_xdp(struct bnxt *bp, struct bnxt_napi *bnapi, int nr_pkts)
+{
+	struct bnxt_tx_ring_info *txr = bnapi->tx_ring;
+	struct bnxt_rx_ring_info *rxr = bnapi->rx_ring;
+	bool rx_doorbell_needed = false;
+	struct bnxt_sw_tx_bd *tx_buf;
+	u16 tx_cons = txr->tx_cons;
+	u16 last_tx_cons = tx_cons;
+	int i, j, frags;
+
+	for (i = 0; i < nr_pkts; i++) {
+		tx_buf = &txr->tx_buf_ring[tx_cons];
+
+		if (tx_buf->action == XDP_REDIRECT) {
+			struct pci_dev *pdev = bp->pdev;
+
+			dma_unmap_single(&pdev->dev,
+					 dma_unmap_addr(tx_buf, mapping),
+					 dma_unmap_len(tx_buf, len),
+					 DMA_TO_DEVICE);
+			xdp_return_frame(tx_buf->xdpf);
+			tx_buf->action = 0;
+			tx_buf->xdpf = NULL;
+		} else if (tx_buf->action == XDP_TX) {
+			rx_doorbell_needed = true;
+			last_tx_cons = tx_cons;
+
+			frags = tx_buf->nr_frags;
+			for (j = 0; j < frags; j++) {
+				tx_cons = NEXT_TX(tx_cons);
+				tx_buf = &txr->tx_buf_ring[tx_cons];
+				page_pool_recycle_direct(rxr->page_pool, tx_buf->page);
+			}
+		}
+		tx_cons = NEXT_TX(tx_cons);
+	}
+	txr->tx_cons = tx_cons;
+	if (rx_doorbell_needed) {
+		tx_buf = &txr->tx_buf_ring[last_tx_cons];
+		bnxt_db_write(bp, &rxr->rx_db, tx_buf->rx_prod);
+
+	}
+}
+
+bool bnxt_xdp_attached(struct bnxt *bp, struct bnxt_rx_ring_info *rxr)
+{
+	struct bpf_prog *xdp_prog = READ_ONCE(rxr->xdp_prog);
+
+	return !!xdp_prog;
+}
+
+void bnxt_xdp_buff_init(struct bnxt *bp, struct bnxt_rx_ring_info *rxr,
+			u16 cons, u8 *data_ptr, unsigned int len,
+			struct xdp_buff *xdp)
+{
+	u32 buflen = BNXT_RX_PAGE_SIZE;
+	struct bnxt_sw_rx_bd *rx_buf;
+	struct pci_dev *pdev;
+	dma_addr_t mapping;
+	u32 offset;
+
+	pdev = bp->pdev;
+	rx_buf = &rxr->rx_buf_ring[cons];
+	offset = bp->rx_offset;
+
+	mapping = rx_buf->mapping - bp->rx_dma_offset;
+	dma_sync_single_for_cpu(&pdev->dev, mapping + offset, len, bp->rx_dir);
+
+	xdp_init_buff(xdp, buflen, &rxr->xdp_rxq);
+	xdp_prepare_buff(xdp, data_ptr - offset, offset, len, false);
+}
+
+void bnxt_xdp_buff_frags_free(struct bnxt_rx_ring_info *rxr,
+			      struct xdp_buff *xdp)
+{
+	struct skb_shared_info *shinfo;
+	int i;
+
+	if (!xdp || !xdp_buff_has_frags(xdp))
+		return;
+	shinfo = xdp_get_shared_info_from_buff(xdp);
+	for (i = 0; i < shinfo->nr_frags; i++) {
+		struct page *page = skb_frag_page(&shinfo->frags[i]);
+
+		page_pool_recycle_direct(rxr->page_pool, page);
+	}
+	shinfo->nr_frags = 0;
+}
+
+/* returns the following:
+ * true    - packet consumed by XDP and new buffer is allocated.
+ * false   - packet should be passed to the stack.
+ */
+bool bnxt_rx_xdp(struct bnxt *bp, struct bnxt_rx_ring_info *rxr, u16 cons,
+		 struct xdp_buff xdp, struct page *page, u8 **data_ptr,
+		 unsigned int *len, u8 *event)
+{
+	struct bpf_prog *xdp_prog = READ_ONCE(rxr->xdp_prog);
+	struct bnxt_tx_ring_info *txr;
+	struct bnxt_sw_rx_bd *rx_buf;
+	struct pci_dev *pdev;
+	dma_addr_t mapping;
+	u32 tx_needed = 1;
+	void *orig_data;
+	u32 tx_avail;
+	u32 offset;
+	u32 act;
+
+	if (!xdp_prog)
+		return false;
+
+	pdev = bp->pdev;
+	offset = bp->rx_offset;
+
+	txr = rxr->bnapi->tx_ring;
+	/* BNXT_RX_PAGE_MODE(bp) when XDP enabled */
+	orig_data = xdp.data;
+
+	act = bpf_prog_run_xdp(xdp_prog, &xdp);
+
+	tx_avail = bnxt_tx_avail(bp, txr);
+	/* If the tx ring is not full, we must not update the rx producer yet
+	 * because we may still be transmitting on some BDs.
+	 */
+	if (tx_avail != bp->tx_ring_size)
+		*event &= ~BNXT_RX_EVENT;
+
+	*len = xdp.data_end - xdp.data;
+	if (orig_data != xdp.data) {
+		offset = xdp.data - xdp.data_hard_start;
+		*data_ptr = xdp.data_hard_start + offset;
+	}
+
+	switch (act) {
+	case XDP_PASS:
+		return false;
+
+	case XDP_TX:
+		rx_buf = &rxr->rx_buf_ring[cons];
+		mapping = rx_buf->mapping - bp->rx_dma_offset;
+		*event = 0;
+
+		if (unlikely(xdp_buff_has_frags(&xdp))) {
+			struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(&xdp);
+
+			tx_needed += sinfo->nr_frags;
+			*event = BNXT_AGG_EVENT;
+		}
+
+		if (tx_avail < tx_needed) {
+			trace_xdp_exception(bp->dev, xdp_prog, act);
+			bnxt_xdp_buff_frags_free(rxr, &xdp);
+			bnxt_reuse_rx_data(rxr, cons, page);
+			return true;
+		}
+
+		dma_sync_single_for_device(&pdev->dev, mapping + offset, *len,
+					   bp->rx_dir);
+
+		*event |= BNXT_TX_EVENT;
+		__bnxt_xmit_xdp(bp, txr, mapping + offset, *len,
+				NEXT_RX(rxr->rx_prod), &xdp);
+		bnxt_reuse_rx_data(rxr, cons, page);
+		return true;
+	case XDP_REDIRECT:
+		/* if we are calling this here then we know that the
+		 * redirect is coming from a frame received by the
+		 * bnxt_en driver.
+		 */
+		rx_buf = &rxr->rx_buf_ring[cons];
+		mapping = rx_buf->mapping - bp->rx_dma_offset;
+		dma_unmap_page_attrs(&pdev->dev, mapping,
+				     BNXT_RX_PAGE_SIZE, bp->rx_dir,
+				     DMA_ATTR_WEAK_ORDERING);
+
+		/* if we are unable to allocate a new buffer, abort and reuse */
+		if (bnxt_alloc_rx_data(bp, rxr, rxr->rx_prod, GFP_ATOMIC)) {
+			trace_xdp_exception(bp->dev, xdp_prog, act);
+			bnxt_xdp_buff_frags_free(rxr, &xdp);
+			bnxt_reuse_rx_data(rxr, cons, page);
+			return true;
+		}
+
+		if (xdp_do_redirect(bp->dev, &xdp, xdp_prog)) {
+			trace_xdp_exception(bp->dev, xdp_prog, act);
+			page_pool_recycle_direct(rxr->page_pool, page);
+			return true;
+		}
+
+		*event |= BNXT_REDIRECT_EVENT;
+		break;
+	default:
+		bpf_warn_invalid_xdp_action(bp->dev, xdp_prog, act);
+		fallthrough;
+	case XDP_ABORTED:
+		trace_xdp_exception(bp->dev, xdp_prog, act);
+		fallthrough;
+	case XDP_DROP:
+		bnxt_xdp_buff_frags_free(rxr, &xdp);
+		bnxt_reuse_rx_data(rxr, cons, page);
+		break;
+	}
+	return true;
+}
+
+int bnxt_xdp_xmit(struct net_device *dev, int num_frames,
+		  struct xdp_frame **frames, u32 flags)
+{
+	struct bnxt *bp = netdev_priv(dev);
+	struct bpf_prog *xdp_prog = READ_ONCE(bp->xdp_prog);
+	struct pci_dev *pdev = bp->pdev;
+	struct bnxt_tx_ring_info *txr;
+	dma_addr_t mapping;
+	int nxmit = 0;
+	int ring;
+	int i;
+
+	if (!test_bit(BNXT_STATE_OPEN, &bp->state) ||
+	    !bp->tx_nr_rings_xdp ||
+	    !xdp_prog)
+		return -EINVAL;
+
+	ring = smp_processor_id() % bp->tx_nr_rings_xdp;
+	txr = &bp->tx_ring[ring];
+
+	if (READ_ONCE(txr->dev_state) == BNXT_DEV_STATE_CLOSING)
+		return -EINVAL;
+
+	if (static_branch_unlikely(&bnxt_xdp_locking_key))
+		spin_lock(&txr->xdp_tx_lock);
+
+	for (i = 0; i < num_frames; i++) {
+		struct xdp_frame *xdp = frames[i];
+
+		if (!bnxt_tx_avail(bp, txr))
+			break;
+
+		mapping = dma_map_single(&pdev->dev, xdp->data, xdp->len,
+					 DMA_TO_DEVICE);
+
+		if (dma_mapping_error(&pdev->dev, mapping))
+			break;
+
+		__bnxt_xmit_xdp_redirect(bp, txr, mapping, xdp->len, xdp);
+		nxmit++;
+	}
+
+	if (flags & XDP_XMIT_FLUSH) {
+		/* Sync BD data before updating doorbell */
+		wmb();
+		bnxt_db_write(bp, &txr->tx_db, txr->tx_prod);
+	}
+
+	if (static_branch_unlikely(&bnxt_xdp_locking_key))
+		spin_unlock(&txr->xdp_tx_lock);
+
+	return nxmit;
+}
+
+/* Under rtnl_lock */
+static int bnxt_xdp_set(struct bnxt *bp, struct bpf_prog *prog)
+{
+	struct net_device *dev = bp->dev;
+	int tx_xdp = 0, rc, tc;
+	struct bpf_prog *old;
+
+	if (prog && !prog->aux->xdp_has_frags &&
+	    bp->dev->mtu > BNXT_MAX_PAGE_MODE_MTU) {
+		netdev_warn(dev, "MTU %d larger than %d without XDP frag support.\n",
+			    bp->dev->mtu, BNXT_MAX_PAGE_MODE_MTU);
+		return -EOPNOTSUPP;
+	}
+	if (!(bp->flags & BNXT_FLAG_SHARED_RINGS)) {
+		netdev_warn(dev, "ethtool rx/tx channels must be combined to support XDP.\n");
+		return -EOPNOTSUPP;
+	}
+	if (prog)
+		tx_xdp = bp->rx_nr_rings;
+
+	tc = netdev_get_num_tc(dev);
+	if (!tc)
+		tc = 1;
+	rc = bnxt_check_rings(bp, bp->tx_nr_rings_per_tc, bp->rx_nr_rings,
+			      true, tc, tx_xdp);
+	if (rc) {
+		netdev_warn(dev, "Unable to reserve enough TX rings to support XDP.\n");
+		return rc;
+	}
+	if (netif_running(dev))
+		bnxt_close_nic(bp, true, false);
+
+	old = xchg(&bp->xdp_prog, prog);
+	if (old)
+		bpf_prog_put(old);
+
+	if (prog) {
+		bnxt_set_rx_skb_mode(bp, true);
+	} else {
+		int rx, tx;
+
+		bnxt_set_rx_skb_mode(bp, false);
+		bnxt_get_max_rings(bp, &rx, &tx, true);
+		if (rx > 1) {
+			bp->flags &= ~BNXT_FLAG_NO_AGG_RINGS;
+			bp->dev->hw_features |= NETIF_F_LRO;
+		}
+	}
+	bp->tx_nr_rings_xdp = tx_xdp;
+	bp->tx_nr_rings = bp->tx_nr_rings_per_tc * tc + tx_xdp;
+	bp->cp_nr_rings = max_t(int, bp->tx_nr_rings, bp->rx_nr_rings);
+	bnxt_set_tpa_flags(bp);
+	bnxt_set_ring_params(bp);
+
+	if (netif_running(dev))
+		return bnxt_open_nic(bp, true, false);
+
+	return 0;
+}
+
+int bnxt_xdp(struct net_device *dev, struct netdev_bpf *xdp)
+{
+	struct bnxt *bp = netdev_priv(dev);
+	int rc;
+
+	switch (xdp->command) {
+	case XDP_SETUP_PROG:
+		rc = bnxt_xdp_set(bp, xdp->prog);
+		break;
+	default:
+		rc = -EINVAL;
+		break;
+	}
+	return rc;
+}
+
+struct sk_buff *
+bnxt_xdp_build_skb(struct bnxt *bp, struct sk_buff *skb, u8 num_frags,
+		   struct page_pool *pool, struct xdp_buff *xdp,
+		   struct rx_cmp_ext *rxcmp1)
+{
+	struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
+
+	if (!skb)
+		return NULL;
+	skb_checksum_none_assert(skb);
+	if (RX_CMP_L4_CS_OK(rxcmp1)) {
+		if (bp->dev->features & NETIF_F_RXCSUM) {
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+			skb->csum_level = RX_CMP_ENCAP(rxcmp1);
+		}
+	}
+	xdp_update_skb_shared_info(skb, num_frags,
+				   sinfo->xdp_frags_size,
+				   BNXT_RX_PAGE_SIZE * sinfo->nr_frags,
+				   xdp_buff_is_frag_pfmemalloc(xdp));
+	return skb;
+}