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aquantia: Remove the build_skb path 

When performing IPv6 forwarding, there is an expectation that SKBs
will have some headroom. When forwarding a packet from the aquantia
driver, this does not always happen, triggering a kernel warning.

aq_ring.c has this code (edited slightly for brevity):

if (buff->is_eop && buff->len <= AQ_CFG_RX_FRAME_MAX - AQ_SKB_ALIGN) {
    skb = build_skb(aq_buf_vaddr(&buff->rxdata), AQ_CFG_RX_FRAME_MAX);
} else {
    skb = napi_alloc_skb(napi, AQ_CFG_RX_HDR_SIZE);

There is a significant difference between the SKB produced by these
2 code paths. When napi_alloc_skb creates an SKB, there is a certain
amount of headroom reserved. However, this is not done in the
build_skb codepath.

As the hardware buffer that build_skb is built around does not
handle the presence of the SKB header, this code path is being
removed and the napi_alloc_skb path will always be used. This code
path does have to copy the packet header into the SKB, but it adds
the packet data as a frag.

Fixes: 018423e90b ("net: ethernet: aquantia: Add ring support code")
Signed-off-by: Lincoln Ramsay <lincoln.ramsay@opengear.com>
Link: https://lore.kernel.org/r/MWHPR1001MB23184F3EAFA413E0D1910EC9E8FC0@MWHPR1001MB2318.namprd10.prod.outlook.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Lincoln Ramsay 2020-11-23 21:40:43 +00:00 committed by Jakub Kicinski
parent d549699048
commit 9bd2702d29
1 changed files with 50 additions and 72 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

122
drivers/net/ethernet/aquantia/atlantic/aq_ring.c
View File

@ -413,85 +413,63 @@ int aq_ring_rx_clean(struct aq_ring_s *self,
buff->rxdata.pg_off,
buff->len, DMA_FROM_DEVICE);
/* for single fragment packets use build_skb() */
if (buff->is_eop &&
buff->len <= AQ_CFG_RX_FRAME_MAX - AQ_SKB_ALIGN) {
skb = build_skb(aq_buf_vaddr(&buff->rxdata),
skb = napi_alloc_skb(napi, AQ_CFG_RX_HDR_SIZE);
if (unlikely(!skb)) {
u64_stats_update_begin(&self->stats.rx.syncp);
self->stats.rx.skb_alloc_fails++;
u64_stats_update_end(&self->stats.rx.syncp);
err = -ENOMEM;
goto err_exit;
}
if (is_ptp_ring)
buff->len -=
aq_ptp_extract_ts(self->aq_nic, skb,
aq_buf_vaddr(&buff->rxdata),
buff->len);
hdr_len = buff->len;
if (hdr_len > AQ_CFG_RX_HDR_SIZE)
hdr_len = eth_get_headlen(skb->dev,
aq_buf_vaddr(&buff->rxdata),
AQ_CFG_RX_HDR_SIZE);
memcpy(__skb_put(skb, hdr_len), aq_buf_vaddr(&buff->rxdata),
ALIGN(hdr_len, sizeof(long)));
if (buff->len - hdr_len > 0) {
skb_add_rx_frag(skb, 0, buff->rxdata.page,
buff->rxdata.pg_off + hdr_len,
buff->len - hdr_len,
AQ_CFG_RX_FRAME_MAX);
if (unlikely(!skb)) {
u64_stats_update_begin(&self->stats.rx.syncp);
self->stats.rx.skb_alloc_fails++;
u64_stats_update_end(&self->stats.rx.syncp);
err = -ENOMEM;
goto err_exit;
}
if (is_ptp_ring)
buff->len -=
aq_ptp_extract_ts(self->aq_nic, skb,
aq_buf_vaddr(&buff->rxdata),
buff->len);
skb_put(skb, buff->len);
page_ref_inc(buff->rxdata.page);
} else {
skb = napi_alloc_skb(napi, AQ_CFG_RX_HDR_SIZE);
if (unlikely(!skb)) {
u64_stats_update_begin(&self->stats.rx.syncp);
self->stats.rx.skb_alloc_fails++;
u64_stats_update_end(&self->stats.rx.syncp);
err = -ENOMEM;
goto err_exit;
}
if (is_ptp_ring)
buff->len -=
aq_ptp_extract_ts(self->aq_nic, skb,
aq_buf_vaddr(&buff->rxdata),
buff->len);
}
hdr_len = buff->len;
if (hdr_len > AQ_CFG_RX_HDR_SIZE)
hdr_len = eth_get_headlen(skb->dev,
aq_buf_vaddr(&buff->rxdata),
AQ_CFG_RX_HDR_SIZE);
if (!buff->is_eop) {
buff_ = buff;
i = 1U;
do {
next_ = buff_->next;
buff_ = &self->buff_ring[next_];
memcpy(__skb_put(skb, hdr_len), aq_buf_vaddr(&buff->rxdata),
ALIGN(hdr_len, sizeof(long)));
if (buff->len - hdr_len > 0) {
skb_add_rx_frag(skb, 0, buff->rxdata.page,
buff->rxdata.pg_off + hdr_len,
buff->len - hdr_len,
dma_sync_single_range_for_cpu(aq_nic_get_dev(self->aq_nic),
buff_->rxdata.daddr,
buff_->rxdata.pg_off,
buff_->len,
DMA_FROM_DEVICE);
skb_add_rx_frag(skb, i++,
buff_->rxdata.page,
buff_->rxdata.pg_off,
buff_->len,
AQ_CFG_RX_FRAME_MAX);
page_ref_inc(buff->rxdata.page);
}
page_ref_inc(buff_->rxdata.page);
buff_->is_cleaned = 1;
if (!buff->is_eop) {
buff_ = buff;
i = 1U;
do {
next_ = buff_->next,
buff_ = &self->buff_ring[next_];
buff->is_ip_cso &= buff_->is_ip_cso;
buff->is_udp_cso &= buff_->is_udp_cso;
buff->is_tcp_cso &= buff_->is_tcp_cso;
buff->is_cso_err |= buff_->is_cso_err;
dma_sync_single_range_for_cpu(
aq_nic_get_dev(self->aq_nic),
buff_->rxdata.daddr,
buff_->rxdata.pg_off,
buff_->len,
DMA_FROM_DEVICE);
skb_add_rx_frag(skb, i++,
buff_->rxdata.page,
buff_->rxdata.pg_off,
buff_->len,
AQ_CFG_RX_FRAME_MAX);
page_ref_inc(buff_->rxdata.page);
buff_->is_cleaned = 1;
buff->is_ip_cso &= buff_->is_ip_cso;
buff->is_udp_cso &= buff_->is_udp_cso;
buff->is_tcp_cso &= buff_->is_tcp_cso;
buff->is_cso_err |= buff_->is_cso_err;
} while (!buff_->is_eop);
}
} while (!buff_->is_eop);
}
if (buff->is_vlan)