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