1 files changed, 465 insertions, 0 deletions

diff --git a/drivers/net/ethernet/amazon/ena/ena_xdp.c b/drivers/net/ethernet/amazon/ena/ena_xdp.c
new file mode 100644
index 000000000000..d0c8a2dc9a67
--- /dev/null
+++ b/drivers/net/ethernet/amazon/ena/ena_xdp.c
@@ -0,0 +1,465 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/*
+ * Copyright 2015-2021 Amazon.com, Inc. or its affiliates. All rights reserved.
+ */
+
+#include "ena_xdp.h"
+
+static int validate_xdp_req_id(struct ena_ring *xdp_ring, u16 req_id)
+{
+	struct ena_tx_buffer *tx_info;
+
+	tx_info = &xdp_ring->tx_buffer_info[req_id];
+	if (likely(tx_info->xdpf))
+		return 0;
+
+	return handle_invalid_req_id(xdp_ring, req_id, tx_info, true);
+}
+
+static int ena_xdp_tx_map_frame(struct ena_ring *xdp_ring,
+				struct ena_tx_buffer *tx_info,
+				struct xdp_frame *xdpf,
+				struct ena_com_tx_ctx *ena_tx_ctx)
+{
+	struct ena_adapter *adapter = xdp_ring->adapter;
+	struct ena_com_buf *ena_buf;
+	int push_len = 0;
+	dma_addr_t dma;
+	void *data;
+	u32 size;
+
+	tx_info->xdpf = xdpf;
+	data = tx_info->xdpf->data;
+	size = tx_info->xdpf->len;
+
+	if (xdp_ring->tx_mem_queue_type == ENA_ADMIN_PLACEMENT_POLICY_DEV) {
+		/* Designate part of the packet for LLQ */
+		push_len = min_t(u32, size, xdp_ring->tx_max_header_size);
+
+		ena_tx_ctx->push_header = data;
+
+		size -= push_len;
+		data += push_len;
+	}
+
+	ena_tx_ctx->header_len = push_len;
+
+	if (size > 0) {
+		dma = dma_map_single(xdp_ring->dev,
+				     data,
+				     size,
+				     DMA_TO_DEVICE);
+		if (unlikely(dma_mapping_error(xdp_ring->dev, dma)))
+			goto error_report_dma_error;
+
+		tx_info->map_linear_data = 0;
+
+		ena_buf = tx_info->bufs;
+		ena_buf->paddr = dma;
+		ena_buf->len = size;
+
+		ena_tx_ctx->ena_bufs = ena_buf;
+		ena_tx_ctx->num_bufs = tx_info->num_of_bufs = 1;
+	}
+
+	return 0;
+
+error_report_dma_error:
+	ena_increase_stat(&xdp_ring->tx_stats.dma_mapping_err, 1,
+			  &xdp_ring->syncp);
+	netif_warn(adapter, tx_queued, adapter->netdev, "Failed to map xdp buff\n");
+
+	return -EINVAL;
+}
+
+int ena_xdp_xmit_frame(struct ena_ring *xdp_ring,
+		       struct net_device *dev,
+		       struct xdp_frame *xdpf,
+		       int flags)
+{
+	struct ena_com_tx_ctx ena_tx_ctx = {};
+	struct ena_tx_buffer *tx_info;
+	u16 next_to_use, req_id;
+	int rc;
+
+	next_to_use = xdp_ring->next_to_use;
+	req_id = xdp_ring->free_ids[next_to_use];
+	tx_info = &xdp_ring->tx_buffer_info[req_id];
+	tx_info->num_of_bufs = 0;
+
+	rc = ena_xdp_tx_map_frame(xdp_ring, tx_info, xdpf, &ena_tx_ctx);
+	if (unlikely(rc))
+		return rc;
+
+	ena_tx_ctx.req_id = req_id;
+
+	rc = ena_xmit_common(dev,
+			     xdp_ring,
+			     tx_info,
+			     &ena_tx_ctx,
+			     next_to_use,
+			     xdpf->len);
+	if (rc)
+		goto error_unmap_dma;
+
+	/* trigger the dma engine. ena_ring_tx_doorbell()
+	 * calls a memory barrier inside it.
+	 */
+	if (flags & XDP_XMIT_FLUSH)
+		ena_ring_tx_doorbell(xdp_ring);
+
+	return rc;
+
+error_unmap_dma:
+	ena_unmap_tx_buff(xdp_ring, tx_info);
+	tx_info->xdpf = NULL;
+	return rc;
+}
+
+int ena_xdp_xmit(struct net_device *dev, int n,
+		 struct xdp_frame **frames, u32 flags)
+{
+	struct ena_adapter *adapter = netdev_priv(dev);
+	struct ena_ring *xdp_ring;
+	int qid, i, nxmit = 0;
+
+	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
+		return -EINVAL;
+
+	if (!test_bit(ENA_FLAG_DEV_UP, &adapter->flags))
+		return -ENETDOWN;
+
+	/* We assume that all rings have the same XDP program */
+	if (!READ_ONCE(adapter->rx_ring->xdp_bpf_prog))
+		return -ENXIO;
+
+	qid = smp_processor_id() % adapter->xdp_num_queues;
+	qid += adapter->xdp_first_ring;
+	xdp_ring = &adapter->tx_ring[qid];
+
+	/* Other CPU ids might try to send thorugh this queue */
+	spin_lock(&xdp_ring->xdp_tx_lock);
+
+	for (i = 0; i < n; i++) {
+		if (ena_xdp_xmit_frame(xdp_ring, dev, frames[i], 0))
+			break;
+		nxmit++;
+	}
+
+	/* Ring doorbell to make device aware of the packets */
+	if (flags & XDP_XMIT_FLUSH)
+		ena_ring_tx_doorbell(xdp_ring);
+
+	spin_unlock(&xdp_ring->xdp_tx_lock);
+
+	/* Return number of packets sent */
+	return nxmit;
+}
+
+static void ena_init_all_xdp_queues(struct ena_adapter *adapter)
+{
+	adapter->xdp_first_ring = adapter->num_io_queues;
+	adapter->xdp_num_queues = adapter->num_io_queues;
+
+	ena_init_io_rings(adapter,
+			  adapter->xdp_first_ring,
+			  adapter->xdp_num_queues);
+}
+
+int ena_setup_and_create_all_xdp_queues(struct ena_adapter *adapter)
+{
+	u32 xdp_first_ring = adapter->xdp_first_ring;
+	u32 xdp_num_queues = adapter->xdp_num_queues;
+	int rc = 0;
+
+	rc = ena_setup_tx_resources_in_range(adapter, xdp_first_ring, xdp_num_queues);
+	if (rc)
+		goto setup_err;
+
+	rc = ena_create_io_tx_queues_in_range(adapter, xdp_first_ring, xdp_num_queues);
+	if (rc)
+		goto create_err;
+
+	return 0;
+
+create_err:
+	ena_free_all_io_tx_resources_in_range(adapter, xdp_first_ring, xdp_num_queues);
+setup_err:
+	return rc;
+}
+
+/* Provides a way for both kernel and bpf-prog to know
+ * more about the RX-queue a given XDP frame arrived on.
+ */
+static int ena_xdp_register_rxq_info(struct ena_ring *rx_ring)
+{
+	int rc;
+
+	rc = xdp_rxq_info_reg(&rx_ring->xdp_rxq, rx_ring->netdev, rx_ring->qid, 0);
+
+	if (rc) {
+		netif_err(rx_ring->adapter, ifup, rx_ring->netdev,
+			  "Failed to register xdp rx queue info. RX queue num %d rc: %d\n",
+			  rx_ring->qid, rc);
+		goto err;
+	}
+
+	rc = xdp_rxq_info_reg_mem_model(&rx_ring->xdp_rxq, MEM_TYPE_PAGE_SHARED, NULL);
+
+	if (rc) {
+		netif_err(rx_ring->adapter, ifup, rx_ring->netdev,
+			  "Failed to register xdp rx queue info memory model. RX queue num %d rc: %d\n",
+			  rx_ring->qid, rc);
+		xdp_rxq_info_unreg(&rx_ring->xdp_rxq);
+	}
+
+err:
+	return rc;
+}
+
+static void ena_xdp_unregister_rxq_info(struct ena_ring *rx_ring)
+{
+	xdp_rxq_info_unreg_mem_model(&rx_ring->xdp_rxq);
+	xdp_rxq_info_unreg(&rx_ring->xdp_rxq);
+}
+
+void ena_xdp_exchange_program_rx_in_range(struct ena_adapter *adapter,
+					  struct bpf_prog *prog,
+					  int first, int count)
+{
+	struct bpf_prog *old_bpf_prog;
+	struct ena_ring *rx_ring;
+	int i = 0;
+
+	for (i = first; i < count; i++) {
+		rx_ring = &adapter->rx_ring[i];
+		old_bpf_prog = xchg(&rx_ring->xdp_bpf_prog, prog);
+
+		if (!old_bpf_prog && prog) {
+			ena_xdp_register_rxq_info(rx_ring);
+			rx_ring->rx_headroom = XDP_PACKET_HEADROOM;
+		} else if (old_bpf_prog && !prog) {
+			ena_xdp_unregister_rxq_info(rx_ring);
+			rx_ring->rx_headroom = NET_SKB_PAD;
+		}
+	}
+}
+
+static void ena_xdp_exchange_program(struct ena_adapter *adapter,
+				     struct bpf_prog *prog)
+{
+	struct bpf_prog *old_bpf_prog = xchg(&adapter->xdp_bpf_prog, prog);
+
+	ena_xdp_exchange_program_rx_in_range(adapter,
+					     prog,
+					     0,
+					     adapter->num_io_queues);
+
+	if (old_bpf_prog)
+		bpf_prog_put(old_bpf_prog);
+}
+
+static int ena_destroy_and_free_all_xdp_queues(struct ena_adapter *adapter)
+{
+	bool was_up;
+	int rc;
+
+	was_up = test_bit(ENA_FLAG_DEV_UP, &adapter->flags);
+
+	if (was_up)
+		ena_down(adapter);
+
+	adapter->xdp_first_ring = 0;
+	adapter->xdp_num_queues = 0;
+	ena_xdp_exchange_program(adapter, NULL);
+	if (was_up) {
+		rc = ena_up(adapter);
+		if (rc)
+			return rc;
+	}
+	return 0;
+}
+
+static int ena_xdp_set(struct net_device *netdev, struct netdev_bpf *bpf)
+{
+	struct ena_adapter *adapter = netdev_priv(netdev);
+	struct bpf_prog *prog = bpf->prog;
+	struct bpf_prog *old_bpf_prog;
+	int rc, prev_mtu;
+	bool is_up;
+
+	is_up = test_bit(ENA_FLAG_DEV_UP, &adapter->flags);
+	rc = ena_xdp_allowed(adapter);
+	if (rc == ENA_XDP_ALLOWED) {
+		old_bpf_prog = adapter->xdp_bpf_prog;
+		if (prog) {
+			if (!is_up) {
+				ena_init_all_xdp_queues(adapter);
+			} else if (!old_bpf_prog) {
+				ena_down(adapter);
+				ena_init_all_xdp_queues(adapter);
+			}
+			ena_xdp_exchange_program(adapter, prog);
+
+			if (is_up && !old_bpf_prog) {
+				rc = ena_up(adapter);
+				if (rc)
+					return rc;
+			}
+			xdp_features_set_redirect_target(netdev, false);
+		} else if (old_bpf_prog) {
+			xdp_features_clear_redirect_target(netdev);
+			rc = ena_destroy_and_free_all_xdp_queues(adapter);
+			if (rc)
+				return rc;
+		}
+
+		prev_mtu = netdev->max_mtu;
+		netdev->max_mtu = prog ? ENA_XDP_MAX_MTU : adapter->max_mtu;
+
+		if (!old_bpf_prog)
+			netif_info(adapter, drv, adapter->netdev,
+				   "XDP program is set, changing the max_mtu from %d to %d",
+				   prev_mtu, netdev->max_mtu);
+
+	} else if (rc == ENA_XDP_CURRENT_MTU_TOO_LARGE) {
+		netif_err(adapter, drv, adapter->netdev,
+			  "Failed to set xdp program, the current MTU (%d) is larger than the maximum allowed MTU (%lu) while xdp is on",
+			  netdev->mtu, ENA_XDP_MAX_MTU);
+		NL_SET_ERR_MSG_MOD(bpf->extack,
+				   "Failed to set xdp program, the current MTU is larger than the maximum allowed MTU. Check the dmesg for more info");
+		return -EINVAL;
+	} else if (rc == ENA_XDP_NO_ENOUGH_QUEUES) {
+		netif_err(adapter, drv, adapter->netdev,
+			  "Failed to set xdp program, the Rx/Tx channel count should be at most half of the maximum allowed channel count. The current queue count (%d), the maximal queue count (%d)\n",
+			  adapter->num_io_queues, adapter->max_num_io_queues);
+		NL_SET_ERR_MSG_MOD(bpf->extack,
+				   "Failed to set xdp program, there is no enough space for allocating XDP queues, Check the dmesg for more info");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/* This is the main xdp callback, it's used by the kernel to set/unset the xdp
+ * program as well as to query the current xdp program id.
+ */
+int ena_xdp(struct net_device *netdev, struct netdev_bpf *bpf)
+{
+	switch (bpf->command) {
+	case XDP_SETUP_PROG:
+		return ena_xdp_set(netdev, bpf);
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int ena_clean_xdp_irq(struct ena_ring *xdp_ring, u32 budget)
+{
+	u32 total_done = 0;
+	u16 next_to_clean;
+	int tx_pkts = 0;
+	u16 req_id;
+	int rc;
+
+	if (unlikely(!xdp_ring))
+		return 0;
+	next_to_clean = xdp_ring->next_to_clean;
+
+	while (tx_pkts < budget) {
+		struct ena_tx_buffer *tx_info;
+		struct xdp_frame *xdpf;
+
+		rc = ena_com_tx_comp_req_id_get(xdp_ring->ena_com_io_cq,
+						&req_id);
+		if (rc) {
+			if (unlikely(rc == -EINVAL))
+				handle_invalid_req_id(xdp_ring, req_id, NULL,
+						      true);
+			break;
+		}
+
+		/* validate that the request id points to a valid xdp_frame */
+		rc = validate_xdp_req_id(xdp_ring, req_id);
+		if (rc)
+			break;
+
+		tx_info = &xdp_ring->tx_buffer_info[req_id];
+		xdpf = tx_info->xdpf;
+
+		tx_info->xdpf = NULL;
+		tx_info->last_jiffies = 0;
+		ena_unmap_tx_buff(xdp_ring, tx_info);
+
+		netif_dbg(xdp_ring->adapter, tx_done, xdp_ring->netdev,
+			  "tx_poll: q %d skb %p completed\n", xdp_ring->qid,
+			  xdpf);
+
+		tx_pkts++;
+		total_done += tx_info->tx_descs;
+
+		xdp_return_frame(xdpf);
+		xdp_ring->free_ids[next_to_clean] = req_id;
+		next_to_clean = ENA_TX_RING_IDX_NEXT(next_to_clean,
+						     xdp_ring->ring_size);
+	}
+
+	xdp_ring->next_to_clean = next_to_clean;
+	ena_com_comp_ack(xdp_ring->ena_com_io_sq, total_done);
+	ena_com_update_dev_comp_head(xdp_ring->ena_com_io_cq);
+
+	netif_dbg(xdp_ring->adapter, tx_done, xdp_ring->netdev,
+		  "tx_poll: q %d done. total pkts: %d\n",
+		  xdp_ring->qid, tx_pkts);
+
+	return tx_pkts;
+}
+
+/* This is the XDP napi callback. XDP queues use a separate napi callback
+ * than Rx/Tx queues.
+ */
+int ena_xdp_io_poll(struct napi_struct *napi, int budget)
+{
+	struct ena_napi *ena_napi = container_of(napi, struct ena_napi, napi);
+	u32 xdp_work_done, xdp_budget;
+	struct ena_ring *xdp_ring;
+	int napi_comp_call = 0;
+	int ret;
+
+	xdp_ring = ena_napi->xdp_ring;
+
+	xdp_budget = budget;
+
+	if (!test_bit(ENA_FLAG_DEV_UP, &xdp_ring->adapter->flags) ||
+	    test_bit(ENA_FLAG_TRIGGER_RESET, &xdp_ring->adapter->flags)) {
+		napi_complete_done(napi, 0);
+		return 0;
+	}
+
+	xdp_work_done = ena_clean_xdp_irq(xdp_ring, xdp_budget);
+
+	/* If the device is about to reset or down, avoid unmask
+	 * the interrupt and return 0 so NAPI won't reschedule
+	 */
+	if (unlikely(!test_bit(ENA_FLAG_DEV_UP, &xdp_ring->adapter->flags))) {
+		napi_complete_done(napi, 0);
+		ret = 0;
+	} else if (xdp_budget > xdp_work_done) {
+		napi_comp_call = 1;
+		if (napi_complete_done(napi, xdp_work_done))
+			ena_unmask_interrupt(xdp_ring, NULL);
+		ena_update_ring_numa_node(xdp_ring, NULL);
+		ret = xdp_work_done;
+	} else {
+		ret = xdp_budget;
+	}
+
+	u64_stats_update_begin(&xdp_ring->syncp);
+	xdp_ring->tx_stats.napi_comp += napi_comp_call;
+	xdp_ring->tx_stats.tx_poll++;
+	u64_stats_update_end(&xdp_ring->syncp);
+	xdp_ring->tx_stats.last_napi_jiffies = jiffies;
+
+	return ret;
+}