1 files changed, 409 insertions, 0 deletions

diff --git a/drivers/net/ethernet/sfc/rx.c b/drivers/net/ethernet/sfc/rx.c
new file mode 100644
index 0000000000..f77a2d3ef3
--- /dev/null
+++ b/drivers/net/ethernet/sfc/rx.c
@@ -0,0 +1,409 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/****************************************************************************
+ * Driver for Solarflare network controllers and boards
+ * Copyright 2005-2006 Fen Systems Ltd.
+ * Copyright 2005-2013 Solarflare Communications Inc.
+ */
+
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/slab.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <linux/prefetch.h>
+#include <linux/moduleparam.h>
+#include <linux/iommu.h>
+#include <net/ip.h>
+#include <net/checksum.h>
+#include <net/xdp.h>
+#include <linux/bpf_trace.h>
+#include "net_driver.h"
+#include "efx.h"
+#include "rx_common.h"
+#include "filter.h"
+#include "nic.h"
+#include "selftest.h"
+#include "workarounds.h"
+
+/* Preferred number of descriptors to fill at once */
+#define EFX_RX_PREFERRED_BATCH 8U
+
+/* Maximum rx prefix used by any architecture. */
+#define EFX_MAX_RX_PREFIX_SIZE 16
+
+/* Size of buffer allocated for skb header area. */
+#define EFX_SKB_HEADERS  128u
+
+/* Each packet can consume up to ceil(max_frame_len / buffer_size) buffers */
+#define EFX_RX_MAX_FRAGS DIV_ROUND_UP(EFX_MAX_FRAME_LEN(EFX_MAX_MTU), \
+				      EFX_RX_USR_BUF_SIZE)
+
+static void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue,
+				     struct efx_rx_buffer *rx_buf,
+				     int len)
+{
+	struct efx_nic *efx = rx_queue->efx;
+	unsigned max_len = rx_buf->len - efx->type->rx_buffer_padding;
+
+	if (likely(len <= max_len))
+		return;
+
+	/* The packet must be discarded, but this is only a fatal error
+	 * if the caller indicated it was
+	 */
+	rx_buf->flags |= EFX_RX_PKT_DISCARD;
+
+	if (net_ratelimit())
+		netif_err(efx, rx_err, efx->net_dev,
+			  "RX queue %d overlength RX event (%#x > %#x)\n",
+			  efx_rx_queue_index(rx_queue), len, max_len);
+
+	efx_rx_queue_channel(rx_queue)->n_rx_overlength++;
+}
+
+/* Allocate and construct an SKB around page fragments */
+static struct sk_buff *efx_rx_mk_skb(struct efx_channel *channel,
+				     struct efx_rx_buffer *rx_buf,
+				     unsigned int n_frags,
+				     u8 *eh, int hdr_len)
+{
+	struct efx_nic *efx = channel->efx;
+	struct sk_buff *skb;
+
+	/* Allocate an SKB to store the headers */
+	skb = netdev_alloc_skb(efx->net_dev,
+			       efx->rx_ip_align + efx->rx_prefix_size +
+			       hdr_len);
+	if (unlikely(skb == NULL)) {
+		atomic_inc(&efx->n_rx_noskb_drops);
+		return NULL;
+	}
+
+	EFX_WARN_ON_ONCE_PARANOID(rx_buf->len < hdr_len);
+
+	memcpy(skb->data + efx->rx_ip_align, eh - efx->rx_prefix_size,
+	       efx->rx_prefix_size + hdr_len);
+	skb_reserve(skb, efx->rx_ip_align + efx->rx_prefix_size);
+	__skb_put(skb, hdr_len);
+
+	/* Append the remaining page(s) onto the frag list */
+	if (rx_buf->len > hdr_len) {
+		rx_buf->page_offset += hdr_len;
+		rx_buf->len -= hdr_len;
+
+		for (;;) {
+			skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
+					rx_buf->page, rx_buf->page_offset,
+					rx_buf->len, efx->rx_buffer_truesize);
+			rx_buf->page = NULL;
+
+			if (skb_shinfo(skb)->nr_frags == n_frags)
+				break;
+
+			rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
+		}
+	} else {
+		__free_pages(rx_buf->page, efx->rx_buffer_order);
+		rx_buf->page = NULL;
+		n_frags = 0;
+	}
+
+	/* Move past the ethernet header */
+	skb->protocol = eth_type_trans(skb, efx->net_dev);
+
+	skb_mark_napi_id(skb, &channel->napi_str);
+
+	return skb;
+}
+
+void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,
+		   unsigned int n_frags, unsigned int len, u16 flags)
+{
+	struct efx_nic *efx = rx_queue->efx;
+	struct efx_channel *channel = efx_rx_queue_channel(rx_queue);
+	struct efx_rx_buffer *rx_buf;
+
+	rx_queue->rx_packets++;
+
+	rx_buf = efx_rx_buffer(rx_queue, index);
+	rx_buf->flags |= flags;
+
+	/* Validate the number of fragments and completed length */
+	if (n_frags == 1) {
+		if (!(flags & EFX_RX_PKT_PREFIX_LEN))
+			efx_rx_packet__check_len(rx_queue, rx_buf, len);
+	} else if (unlikely(n_frags > EFX_RX_MAX_FRAGS) ||
+		   unlikely(len <= (n_frags - 1) * efx->rx_dma_len) ||
+		   unlikely(len > n_frags * efx->rx_dma_len) ||
+		   unlikely(!efx->rx_scatter)) {
+		/* If this isn't an explicit discard request, either
+		 * the hardware or the driver is broken.
+		 */
+		WARN_ON(!(len == 0 && rx_buf->flags & EFX_RX_PKT_DISCARD));
+		rx_buf->flags |= EFX_RX_PKT_DISCARD;
+	}
+
+	netif_vdbg(efx, rx_status, efx->net_dev,
+		   "RX queue %d received ids %x-%x len %d %s%s\n",
+		   efx_rx_queue_index(rx_queue), index,
+		   (index + n_frags - 1) & rx_queue->ptr_mask, len,
+		   (rx_buf->flags & EFX_RX_PKT_CSUMMED) ? " [SUMMED]" : "",
+		   (rx_buf->flags & EFX_RX_PKT_DISCARD) ? " [DISCARD]" : "");
+
+	/* Discard packet, if instructed to do so.  Process the
+	 * previous receive first.
+	 */
+	if (unlikely(rx_buf->flags & EFX_RX_PKT_DISCARD)) {
+		efx_rx_flush_packet(channel);
+		efx_discard_rx_packet(channel, rx_buf, n_frags);
+		return;
+	}
+
+	if (n_frags == 1 && !(flags & EFX_RX_PKT_PREFIX_LEN))
+		rx_buf->len = len;
+
+	/* Release and/or sync the DMA mapping - assumes all RX buffers
+	 * consumed in-order per RX queue.
+	 */
+	efx_sync_rx_buffer(efx, rx_buf, rx_buf->len);
+
+	/* Prefetch nice and early so data will (hopefully) be in cache by
+	 * the time we look at it.
+	 */
+	prefetch(efx_rx_buf_va(rx_buf));
+
+	rx_buf->page_offset += efx->rx_prefix_size;
+	rx_buf->len -= efx->rx_prefix_size;
+
+	if (n_frags > 1) {
+		/* Release/sync DMA mapping for additional fragments.
+		 * Fix length for last fragment.
+		 */
+		unsigned int tail_frags = n_frags - 1;
+
+		for (;;) {
+			rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
+			if (--tail_frags == 0)
+				break;
+			efx_sync_rx_buffer(efx, rx_buf, efx->rx_dma_len);
+		}
+		rx_buf->len = len - (n_frags - 1) * efx->rx_dma_len;
+		efx_sync_rx_buffer(efx, rx_buf, rx_buf->len);
+	}
+
+	/* All fragments have been DMA-synced, so recycle pages. */
+	rx_buf = efx_rx_buffer(rx_queue, index);
+	efx_recycle_rx_pages(channel, rx_buf, n_frags);
+
+	/* Pipeline receives so that we give time for packet headers to be
+	 * prefetched into cache.
+	 */
+	efx_rx_flush_packet(channel);
+	channel->rx_pkt_n_frags = n_frags;
+	channel->rx_pkt_index = index;
+}
+
+static void efx_rx_deliver(struct efx_channel *channel, u8 *eh,
+			   struct efx_rx_buffer *rx_buf,
+			   unsigned int n_frags)
+{
+	struct sk_buff *skb;
+	u16 hdr_len = min_t(u16, rx_buf->len, EFX_SKB_HEADERS);
+
+	skb = efx_rx_mk_skb(channel, rx_buf, n_frags, eh, hdr_len);
+	if (unlikely(skb == NULL)) {
+		struct efx_rx_queue *rx_queue;
+
+		rx_queue = efx_channel_get_rx_queue(channel);
+		efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
+		return;
+	}
+	skb_record_rx_queue(skb, channel->rx_queue.core_index);
+
+	/* Set the SKB flags */
+	skb_checksum_none_assert(skb);
+	if (likely(rx_buf->flags & EFX_RX_PKT_CSUMMED)) {
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+		skb->csum_level = !!(rx_buf->flags & EFX_RX_PKT_CSUM_LEVEL);
+	}
+
+	efx_rx_skb_attach_timestamp(channel, skb);
+
+	if (channel->type->receive_skb)
+		if (channel->type->receive_skb(channel, skb))
+			return;
+
+	/* Pass the packet up */
+	if (channel->rx_list != NULL)
+		/* Add to list, will pass up later */
+		list_add_tail(&skb->list, channel->rx_list);
+	else
+		/* No list, so pass it up now */
+		netif_receive_skb(skb);
+}
+
+/** efx_do_xdp: perform XDP processing on a received packet
+ *
+ * Returns true if packet should still be delivered.
+ */
+static bool efx_do_xdp(struct efx_nic *efx, struct efx_channel *channel,
+		       struct efx_rx_buffer *rx_buf, u8 **ehp)
+{
+	u8 rx_prefix[EFX_MAX_RX_PREFIX_SIZE];
+	struct efx_rx_queue *rx_queue;
+	struct bpf_prog *xdp_prog;
+	struct xdp_frame *xdpf;
+	struct xdp_buff xdp;
+	u32 xdp_act;
+	s16 offset;
+	int err;
+
+	xdp_prog = rcu_dereference_bh(efx->xdp_prog);
+	if (!xdp_prog)
+		return true;
+
+	rx_queue = efx_channel_get_rx_queue(channel);
+
+	if (unlikely(channel->rx_pkt_n_frags > 1)) {
+		/* We can't do XDP on fragmented packets - drop. */
+		efx_free_rx_buffers(rx_queue, rx_buf,
+				    channel->rx_pkt_n_frags);
+		if (net_ratelimit())
+			netif_err(efx, rx_err, efx->net_dev,
+				  "XDP is not possible with multiple receive fragments (%d)\n",
+				  channel->rx_pkt_n_frags);
+		channel->n_rx_xdp_bad_drops++;
+		return false;
+	}
+
+	dma_sync_single_for_cpu(&efx->pci_dev->dev, rx_buf->dma_addr,
+				rx_buf->len, DMA_FROM_DEVICE);
+
+	/* Save the rx prefix. */
+	EFX_WARN_ON_PARANOID(efx->rx_prefix_size > EFX_MAX_RX_PREFIX_SIZE);
+	memcpy(rx_prefix, *ehp - efx->rx_prefix_size,
+	       efx->rx_prefix_size);
+
+	xdp_init_buff(&xdp, efx->rx_page_buf_step, &rx_queue->xdp_rxq_info);
+	/* No support yet for XDP metadata */
+	xdp_prepare_buff(&xdp, *ehp - EFX_XDP_HEADROOM, EFX_XDP_HEADROOM,
+			 rx_buf->len, false);
+
+	xdp_act = bpf_prog_run_xdp(xdp_prog, &xdp);
+
+	offset = (u8 *)xdp.data - *ehp;
+
+	switch (xdp_act) {
+	case XDP_PASS:
+		/* Fix up rx prefix. */
+		if (offset) {
+			*ehp += offset;
+			rx_buf->page_offset += offset;
+			rx_buf->len -= offset;
+			memcpy(*ehp - efx->rx_prefix_size, rx_prefix,
+			       efx->rx_prefix_size);
+		}
+		break;
+
+	case XDP_TX:
+		/* Buffer ownership passes to tx on success. */
+		xdpf = xdp_convert_buff_to_frame(&xdp);
+		err = efx_xdp_tx_buffers(efx, 1, &xdpf, true);
+		if (unlikely(err != 1)) {
+			efx_free_rx_buffers(rx_queue, rx_buf, 1);
+			if (net_ratelimit())
+				netif_err(efx, rx_err, efx->net_dev,
+					  "XDP TX failed (%d)\n", err);
+			channel->n_rx_xdp_bad_drops++;
+			trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);
+		} else {
+			channel->n_rx_xdp_tx++;
+		}
+		break;
+
+	case XDP_REDIRECT:
+		err = xdp_do_redirect(efx->net_dev, &xdp, xdp_prog);
+		if (unlikely(err)) {
+			efx_free_rx_buffers(rx_queue, rx_buf, 1);
+			if (net_ratelimit())
+				netif_err(efx, rx_err, efx->net_dev,
+					  "XDP redirect failed (%d)\n", err);
+			channel->n_rx_xdp_bad_drops++;
+			trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);
+		} else {
+			channel->n_rx_xdp_redirect++;
+		}
+		break;
+
+	default:
+		bpf_warn_invalid_xdp_action(efx->net_dev, xdp_prog, xdp_act);
+		efx_free_rx_buffers(rx_queue, rx_buf, 1);
+		channel->n_rx_xdp_bad_drops++;
+		trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);
+		break;
+
+	case XDP_ABORTED:
+		trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);
+		fallthrough;
+	case XDP_DROP:
+		efx_free_rx_buffers(rx_queue, rx_buf, 1);
+		channel->n_rx_xdp_drops++;
+		break;
+	}
+
+	return xdp_act == XDP_PASS;
+}
+
+/* Handle a received packet.  Second half: Touches packet payload. */
+void __efx_rx_packet(struct efx_channel *channel)
+{
+	struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
+	struct efx_nic *efx = channel->efx;
+	struct efx_rx_buffer *rx_buf =
+		efx_rx_buffer(rx_queue, channel->rx_pkt_index);
+	u8 *eh = efx_rx_buf_va(rx_buf);
+
+	/* Read length from the prefix if necessary.  This already
+	 * excludes the length of the prefix itself.
+	 */
+	if (rx_buf->flags & EFX_RX_PKT_PREFIX_LEN) {
+		rx_buf->len = le16_to_cpup((__le16 *)
+					   (eh + efx->rx_packet_len_offset));
+		/* A known issue may prevent this being filled in;
+		 * if that happens, just drop the packet.
+		 * Must do that in the driver since passing a zero-length
+		 * packet up to the stack may cause a crash.
+		 */
+		if (unlikely(!rx_buf->len)) {
+			efx_free_rx_buffers(rx_queue, rx_buf,
+					    channel->rx_pkt_n_frags);
+			channel->n_rx_frm_trunc++;
+			goto out;
+		}
+	}
+
+	/* If we're in loopback test, then pass the packet directly to the
+	 * loopback layer, and free the rx_buf here
+	 */
+	if (unlikely(efx->loopback_selftest)) {
+		efx_loopback_rx_packet(efx, eh, rx_buf->len);
+		efx_free_rx_buffers(rx_queue, rx_buf,
+				    channel->rx_pkt_n_frags);
+		goto out;
+	}
+
+	if (!efx_do_xdp(efx, channel, rx_buf, &eh))
+		goto out;
+
+	if (unlikely(!(efx->net_dev->features & NETIF_F_RXCSUM)))
+		rx_buf->flags &= ~EFX_RX_PKT_CSUMMED;
+
+	if ((rx_buf->flags & EFX_RX_PKT_TCP) && !channel->type->receive_skb)
+		efx_rx_packet_gro(channel, rx_buf, channel->rx_pkt_n_frags, eh, 0);
+	else
+		efx_rx_deliver(channel, eh, rx_buf, channel->rx_pkt_n_frags);
+out:
+	channel->rx_pkt_n_frags = 0;
+}