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path: root/drivers/net/ethernet/sfc/siena/rx.c
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Diffstat (limited to 'drivers/net/ethernet/sfc/siena/rx.c')
-rw-r--r--drivers/net/ethernet/sfc/siena/rx.c400
1 files changed, 400 insertions, 0 deletions
diff --git a/drivers/net/ethernet/sfc/siena/rx.c b/drivers/net/ethernet/sfc/siena/rx.c
new file mode 100644
index 000000000..98d3c0743
--- /dev/null
+++ b/drivers/net/ethernet/sfc/siena/rx.c
@@ -0,0 +1,400 @@
+// 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_siena_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_siena_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_siena_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_siena_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_siena_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_siena_xdp_tx_buffers(efx, 1, &xdpf, true);
+ if (unlikely(err != 1)) {
+ efx_siena_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_siena_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_siena_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_siena_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_siena_rx_packet(struct efx_channel *channel)
+{
+ struct efx_nic *efx = channel->efx;
+ struct efx_rx_buffer *rx_buf =
+ efx_rx_buffer(&channel->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));
+
+ /* 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)) {
+ struct efx_rx_queue *rx_queue;
+
+ efx_siena_loopback_rx_packet(efx, eh, rx_buf->len);
+ rx_queue = efx_channel_get_rx_queue(channel);
+ efx_siena_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_siena_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;
+}