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gve: Add RX context.
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This refactor moves the skb_head and skb_tail fields into a new
gve_rx_ctx struct. This new struct will contain information about the
current packet being processed. This is in preparation for
multi-descriptor RX packets.

Signed-off-by: David Awogbemila <awogbemila@google.com>
Signed-off-by: Jeroen de Borst <jeroendb@google.com>
Reviewed-by: Catherine Sullivan <csully@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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David Awogbemila authored and David S. Miller committed Oct 25, 2021
1 parent 233cdfb commit 1344e75
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Showing 2 changed files with 44 additions and 37 deletions.
13 changes: 10 additions & 3 deletions drivers/net/ethernet/google/gve/gve.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -142,6 +142,15 @@ struct gve_index_list {
s16 tail;
};

/* A single received packet split across multiple buffers may be
* reconstructed using the information in this structure.
*/
struct gve_rx_ctx {
/* head and tail of skb chain for the current packet or NULL if none */
struct sk_buff *skb_head;
struct sk_buff *skb_tail;
};

/* Contains datapath state used to represent an RX queue. */
struct gve_rx_ring {
struct gve_priv *gve;
Expand Down Expand Up @@ -206,9 +215,7 @@ struct gve_rx_ring {
dma_addr_t q_resources_bus; /* dma address for the queue resources */
struct u64_stats_sync statss; /* sync stats for 32bit archs */

/* head and tail of skb chain for the current packet or NULL if none */
struct sk_buff *skb_head;
struct sk_buff *skb_tail;
struct gve_rx_ctx ctx; /* Info for packet currently being processed in this ring. */
};

/* A TX desc ring entry */
Expand Down
68 changes: 34 additions & 34 deletions drivers/net/ethernet/google/gve/gve_rx_dqo.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -240,8 +240,8 @@ static int gve_rx_alloc_ring_dqo(struct gve_priv *priv, int idx)
rx->dqo.bufq.mask = buffer_queue_slots - 1;
rx->dqo.complq.num_free_slots = completion_queue_slots;
rx->dqo.complq.mask = completion_queue_slots - 1;
rx->skb_head = NULL;
rx->skb_tail = NULL;
rx->ctx.skb_head = NULL;
rx->ctx.skb_tail = NULL;

rx->dqo.num_buf_states = min_t(s16, S16_MAX, buffer_queue_slots * 4);
rx->dqo.buf_states = kvcalloc(rx->dqo.num_buf_states,
Expand Down Expand Up @@ -467,12 +467,12 @@ static void gve_rx_skb_hash(struct sk_buff *skb,

static void gve_rx_free_skb(struct gve_rx_ring *rx)
{
if (!rx->skb_head)
if (!rx->ctx.skb_head)
return;

dev_kfree_skb_any(rx->skb_head);
rx->skb_head = NULL;
rx->skb_tail = NULL;
dev_kfree_skb_any(rx->ctx.skb_head);
rx->ctx.skb_head = NULL;
rx->ctx.skb_tail = NULL;
}

/* Chains multi skbs for single rx packet.
Expand All @@ -483,7 +483,7 @@ static int gve_rx_append_frags(struct napi_struct *napi,
u16 buf_len, struct gve_rx_ring *rx,
struct gve_priv *priv)
{
int num_frags = skb_shinfo(rx->skb_tail)->nr_frags;
int num_frags = skb_shinfo(rx->ctx.skb_tail)->nr_frags;

if (unlikely(num_frags == MAX_SKB_FRAGS)) {
struct sk_buff *skb;
Expand All @@ -492,17 +492,17 @@ static int gve_rx_append_frags(struct napi_struct *napi,
if (!skb)
return -1;

skb_shinfo(rx->skb_tail)->frag_list = skb;
rx->skb_tail = skb;
skb_shinfo(rx->ctx.skb_tail)->frag_list = skb;
rx->ctx.skb_tail = skb;
num_frags = 0;
}
if (rx->skb_tail != rx->skb_head) {
rx->skb_head->len += buf_len;
rx->skb_head->data_len += buf_len;
rx->skb_head->truesize += priv->data_buffer_size_dqo;
if (rx->ctx.skb_tail != rx->ctx.skb_head) {
rx->ctx.skb_head->len += buf_len;
rx->ctx.skb_head->data_len += buf_len;
rx->ctx.skb_head->truesize += priv->data_buffer_size_dqo;
}

skb_add_rx_frag(rx->skb_tail, num_frags,
skb_add_rx_frag(rx->ctx.skb_tail, num_frags,
buf_state->page_info.page,
buf_state->page_info.page_offset,
buf_len, priv->data_buffer_size_dqo);
Expand Down Expand Up @@ -556,7 +556,7 @@ static int gve_rx_dqo(struct napi_struct *napi, struct gve_rx_ring *rx,
buf_len, DMA_FROM_DEVICE);

/* Append to current skb if one exists. */
if (rx->skb_head) {
if (rx->ctx.skb_head) {
if (unlikely(gve_rx_append_frags(napi, buf_state, buf_len, rx,
priv)) != 0) {
goto error;
Expand All @@ -567,11 +567,11 @@ static int gve_rx_dqo(struct napi_struct *napi, struct gve_rx_ring *rx,
}

if (eop && buf_len <= priv->rx_copybreak) {
rx->skb_head = gve_rx_copy(priv->dev, napi,
&buf_state->page_info, buf_len, 0);
if (unlikely(!rx->skb_head))
rx->ctx.skb_head = gve_rx_copy(priv->dev, napi,
&buf_state->page_info, buf_len, 0);
if (unlikely(!rx->ctx.skb_head))
goto error;
rx->skb_tail = rx->skb_head;
rx->ctx.skb_tail = rx->ctx.skb_head;

u64_stats_update_begin(&rx->statss);
rx->rx_copied_pkt++;
Expand All @@ -583,12 +583,12 @@ static int gve_rx_dqo(struct napi_struct *napi, struct gve_rx_ring *rx,
return 0;
}

rx->skb_head = napi_get_frags(napi);
if (unlikely(!rx->skb_head))
rx->ctx.skb_head = napi_get_frags(napi);
if (unlikely(!rx->ctx.skb_head))
goto error;
rx->skb_tail = rx->skb_head;
rx->ctx.skb_tail = rx->ctx.skb_head;

skb_add_rx_frag(rx->skb_head, 0, buf_state->page_info.page,
skb_add_rx_frag(rx->ctx.skb_head, 0, buf_state->page_info.page,
buf_state->page_info.page_offset, buf_len,
priv->data_buffer_size_dqo);
gve_dec_pagecnt_bias(&buf_state->page_info);
Expand Down Expand Up @@ -635,27 +635,27 @@ static int gve_rx_complete_skb(struct gve_rx_ring *rx, struct napi_struct *napi,
rx->gve->ptype_lut_dqo->ptypes[desc->packet_type];
int err;

skb_record_rx_queue(rx->skb_head, rx->q_num);
skb_record_rx_queue(rx->ctx.skb_head, rx->q_num);

if (feat & NETIF_F_RXHASH)
gve_rx_skb_hash(rx->skb_head, desc, ptype);
gve_rx_skb_hash(rx->ctx.skb_head, desc, ptype);

if (feat & NETIF_F_RXCSUM)
gve_rx_skb_csum(rx->skb_head, desc, ptype);
gve_rx_skb_csum(rx->ctx.skb_head, desc, ptype);

/* RSC packets must set gso_size otherwise the TCP stack will complain
* that packets are larger than MTU.
*/
if (desc->rsc) {
err = gve_rx_complete_rsc(rx->skb_head, desc, ptype);
err = gve_rx_complete_rsc(rx->ctx.skb_head, desc, ptype);
if (err < 0)
return err;
}

if (skb_headlen(rx->skb_head) == 0)
if (skb_headlen(rx->ctx.skb_head) == 0)
napi_gro_frags(napi);
else
napi_gro_receive(napi, rx->skb_head);
napi_gro_receive(napi, rx->ctx.skb_head);

return 0;
}
Expand Down Expand Up @@ -717,18 +717,18 @@ int gve_rx_poll_dqo(struct gve_notify_block *block, int budget)
/* Free running counter of completed descriptors */
rx->cnt++;

if (!rx->skb_head)
if (!rx->ctx.skb_head)
continue;

if (!compl_desc->end_of_packet)
continue;

work_done++;
pkt_bytes = rx->skb_head->len;
pkt_bytes = rx->ctx.skb_head->len;
/* The ethernet header (first ETH_HLEN bytes) is snipped off
* by eth_type_trans.
*/
if (skb_headlen(rx->skb_head))
if (skb_headlen(rx->ctx.skb_head))
pkt_bytes += ETH_HLEN;

/* gve_rx_complete_skb() will consume skb if successful */
Expand All @@ -741,8 +741,8 @@ int gve_rx_poll_dqo(struct gve_notify_block *block, int budget)
}

bytes += pkt_bytes;
rx->skb_head = NULL;
rx->skb_tail = NULL;
rx->ctx.skb_head = NULL;
rx->ctx.skb_tail = NULL;
}

gve_rx_post_buffers_dqo(rx);
Expand Down

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