From: Tirthendu Sarkar <tirthendu.sarkar@xxxxxxxxx>
This patch is inspired from the multi-buffer support in non-zc path for
i40e as well as from the patch to support zc on ice. Each subsequent
frag is added to skb_shared_info of the first frag for possible xdp_prog
use as well to xsk buffer list for accessing the buffers in af_xdp.
For XDP_PASS, new pages are allocated for frags and contents are copied
from memory backed by xsk_buff_pool.
Replace next_to_clean with next_to_process as done in non-zc path and
advance it for every buffer and change the semantics of next_to_clean to
point to the first buffer of a packet. Driver will use next_to_process
in the same way next_to_clean was used previously.
For the non multi-buffer case, next_to_process and next_to_clean will
always be the same since each packet consists of a single buffer.
Signed-off-by: Tirthendu Sarkar <tirthendu.sarkar@xxxxxxxxx>
---
drivers/net/ethernet/intel/i40e/i40e_main.c | 5 --
drivers/net/ethernet/intel/i40e/i40e_txrx.c | 4 +-
drivers/net/ethernet/intel/i40e/i40e_txrx.h | 2 +
drivers/net/ethernet/intel/i40e/i40e_xsk.c | 91 ++++++++++++++++++---
4 files changed, 84 insertions(+), 18 deletions(-)
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 29ad1797adce..1bd72cdedc8a 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -3585,11 +3585,6 @@ static int i40e_configure_rx_ring(struct i40e_ring *ring)
if (ring->xsk_pool) {
ring->rx_buf_len =
xsk_pool_get_rx_frame_size(ring->xsk_pool);
- /* For AF_XDP ZC, we disallow packets to span on
- * multiple buffers, thus letting us skip that
- * handling in the fast-path.
- */
- chain_len = 1;
ret = xdp_rxq_info_reg_mem_model(&ring->xdp_rxq,
MEM_TYPE_XSK_BUFF_POOL,
NULL);
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 8b8bf4880faa..0b3a27f118fb 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -2284,8 +2284,8 @@ static struct sk_buff *i40e_build_skb(struct i40e_ring *rx_ring,
* If the buffer is an EOP buffer, this function exits returning false,
* otherwise return true indicating that this is in fact a non-EOP buffer.
*/
-static bool i40e_is_non_eop(struct i40e_ring *rx_ring,
- union i40e_rx_desc *rx_desc)
+bool i40e_is_non_eop(struct i40e_ring *rx_ring,
+ union i40e_rx_desc *rx_desc)
{
/* if we are the last buffer then there is nothing else to do */
#define I40E_RXD_EOF BIT(I40E_RX_DESC_STATUS_EOF_SHIFT)
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.h b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
index 8c3d24012c54..900b0d9ede9f 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
@@ -473,6 +473,8 @@ int __i40e_maybe_stop_tx(struct i40e_ring *tx_ring, int size);
bool __i40e_chk_linearize(struct sk_buff *skb);
int i40e_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames,
u32 flags);
+bool i40e_is_non_eop(struct i40e_ring *rx_ring,
+ union i40e_rx_desc *rx_desc);
/**
* i40e_get_head - Retrieve head from head writeback
diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index 05ec1181471e..89a8aca1153e 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -294,8 +294,14 @@ static struct sk_buff *i40e_construct_skb_zc(struct i40e_ring *rx_ring,
{
unsigned int totalsize = xdp->data_end - xdp->data_meta;
unsigned int metasize = xdp->data - xdp->data_meta;
+ struct skb_shared_info *sinfo = NULL;
struct sk_buff *skb;
+ u32 nr_frags = 0;
+ if (unlikely(xdp_buff_has_frags(xdp))) {
+ sinfo = xdp_get_shared_info_from_buff(xdp);
+ nr_frags = sinfo->nr_frags;
+ }
net_prefetch(xdp->data_meta);
/* allocate a skb to store the frags */
@@ -312,6 +318,28 @@ static struct sk_buff *i40e_construct_skb_zc(struct i40e_ring *rx_ring,
__skb_pull(skb, metasize);
}
+ if (likely(!xdp_buff_has_frags(xdp)))
+ goto out;
+
+ for (int i = 0; i < nr_frags; i++) {
+ struct skb_shared_info *skinfo = skb_shinfo(skb);
+ skb_frag_t *frag = &sinfo->frags[i];
+ struct page *page;
+ void *addr;
+
+ page = dev_alloc_page();
+ if (!page) {
+ dev_kfree_skb(skb);
+ return NULL;
+ }
+ addr = page_to_virt(page);
+
+ memcpy(addr, skb_frag_page(frag), skb_frag_size(frag));
+
+ __skb_fill_page_desc_noacc(skinfo, skinfo->nr_frags++,
+ addr, 0, skb_frag_size(frag));
+ }
+
out:
xsk_buff_free(xdp);
return skb;
@@ -322,14 +350,13 @@ static void i40e_handle_xdp_result_zc(struct i40e_ring *rx_ring,
union i40e_rx_desc *rx_desc,
unsigned int *rx_packets,
unsigned int *rx_bytes,
- unsigned int size,
unsigned int xdp_res,
bool *failure)
{
struct sk_buff *skb;
*rx_packets = 1;
- *rx_bytes = size;
+ *rx_bytes = xdp_get_buff_len(xdp_buff);
if (likely(xdp_res == I40E_XDP_REDIR) || xdp_res == I40E_XDP_TX)
return;
@@ -363,7 +390,6 @@ static void i40e_handle_xdp_result_zc(struct i40e_ring *rx_ring,
return;
}
- *rx_bytes = skb->len;
i40e_process_skb_fields(rx_ring, rx_desc, skb);
napi_gro_receive(&rx_ring->q_vector->napi, skb);
return;
@@ -374,6 +400,31 @@ static void i40e_handle_xdp_result_zc(struct i40e_ring *rx_ring,
WARN_ON_ONCE(1);
}
+static int
+i40e_add_xsk_frag(struct i40e_ring *rx_ring, struct xdp_buff *first,
+ struct xdp_buff *xdp, const unsigned int size)
+{
+ struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(first);
+
+ if (!xdp_buff_has_frags(first)) {
+ sinfo->nr_frags = 0;
+ sinfo->xdp_frags_size = 0;
+ xdp_buff_set_frags_flag(first);
+ }
+
+ if (unlikely(sinfo->nr_frags == MAX_SKB_FRAGS)) {
+ xsk_buff_free(first);
+ return -ENOMEM;
+ }
+
+ __skb_fill_page_desc_noacc(sinfo, sinfo->nr_frags++,
+ virt_to_page(xdp->data_hard_start), 0, size);
+ sinfo->xdp_frags_size += size;
+ xsk_buff_add_frag(xdp);
+
+ return 0;
+}
+
/**
* i40e_clean_rx_irq_zc - Consumes Rx packets from the hardware ring
* @rx_ring: Rx ring
@@ -384,13 +435,18 @@ static void i40e_handle_xdp_result_zc(struct i40e_ring *rx_ring,
int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget)
{
unsigned int total_rx_bytes = 0, total_rx_packets = 0;
+ u16 next_to_process = rx_ring->next_to_process;
u16 next_to_clean = rx_ring->next_to_clean;
u16 count_mask = rx_ring->count - 1;
unsigned int xdp_res, xdp_xmit = 0;
+ struct xdp_buff *first = NULL;
struct bpf_prog *xdp_prog;
bool failure = false;
u16 cleaned_count;
+ if (next_to_process != next_to_clean)
+ first = *i40e_rx_bi(rx_ring, next_to_clean);
+
/* NB! xdp_prog will always be !NULL, due to the fact that
* this path is enabled by setting an XDP program.
*/
@@ -404,7 +460,7 @@ int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget)
unsigned int size;
u64 qword;
- rx_desc = I40E_RX_DESC(rx_ring, next_to_clean);
+ rx_desc = I40E_RX_DESC(rx_ring, next_to_process);
qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
/* This memory barrier is needed to keep us from reading
@@ -417,9 +473,9 @@ int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget)
i40e_clean_programming_status(rx_ring,
rx_desc->raw.qword[0],
qword);
- bi = *i40e_rx_bi(rx_ring, next_to_clean);
+ bi = *i40e_rx_bi(rx_ring, next_to_process);
xsk_buff_free(bi);
- next_to_clean = (next_to_clean + 1) & count_mask;
+ next_to_process = (next_to_process + 1) & count_mask;
continue;
}
@@ -428,22 +484,35 @@ int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget)
if (!size)
break;
- bi = *i40e_rx_bi(rx_ring, next_to_clean);
+ bi = *i40e_rx_bi(rx_ring, next_to_process);
xsk_buff_set_size(bi, size);
xsk_buff_dma_sync_for_cpu(bi, rx_ring->xsk_pool);
- xdp_res = i40e_run_xdp_zc(rx_ring, bi, xdp_prog);
- i40e_handle_xdp_result_zc(rx_ring, bi, rx_desc, &rx_packets,
- &rx_bytes, size, xdp_res, &failure);
+ if (!first)
+ first = bi;
+ else if (i40e_add_xsk_frag(rx_ring, first, bi, size))
+ break;
+
+ next_to_process = (next_to_process + 1) & count_mask;
+
+ if (i40e_is_non_eop(rx_ring, rx_desc))
+ continue;
+
+ xdp_res = i40e_run_xdp_zc(rx_ring, first, xdp_prog);
+ i40e_handle_xdp_result_zc(rx_ring, first, rx_desc, &rx_packets,
+ &rx_bytes, xdp_res, &failure);
+ first->flags = 0;
+ next_to_clean = next_to_process;
if (failure)
break;
total_rx_packets += rx_packets;
total_rx_bytes += rx_bytes;
xdp_xmit |= xdp_res & (I40E_XDP_TX | I40E_XDP_REDIR);
- next_to_clean = (next_to_clean + 1) & count_mask;
+ first = NULL;
}
rx_ring->next_to_clean = next_to_clean;
+ rx_ring->next_to_process = next_to_process;
cleaned_count = (next_to_clean - rx_ring->next_to_use - 1) & count_mask;
if (cleaned_count >= I40E_RX_BUFFER_WRITE)
--
2.34.1
