[bpf-next V1-RFC PATCH 03/14] i40e: setup xdp_rxq_info

[Jesper Dangaard Brouer]

The i40e driver have a special "FDIR" RX-ring (I40E_VSI_FDIR) which is
a sideband channel for configuring/updating the flow director tables.
This (i40e_vsi_)type does not invoke XDP-ebpf code. Thus, mark this
type as a XDP RX-queue type RXQ_TYPE_SINK.

Driver hook points for xdp_rxq_info:
 * init+reg: i40e_setup_rx_descriptors (via i40e_vsi_setup_rx_resources)
 * unreg   : i40e_free_rx_resources    (via i40e_vsi_free_rx_resources)

Tested on actual hardware with samples/bpf program.

Cc: intel-wired-...@lists.osuosl.org
Cc: Björn Töpel <bjorn.to...@intel.com>
Cc: Jeff Kirsher <jeffrey.t.kirs...@intel.com>
Signed-off-by: Jesper Dangaard Brouer <bro...@redhat.com>
---
 drivers/net/ethernet/intel/i40e/i40e_txrx.c |   18 +++++++++++++++++-
 drivers/net/ethernet/intel/i40e/i40e_txrx.h |    3 +++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c 
b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 4566d66ffc7c..d1bfc4232ca9 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -27,6 +27,7 @@
 #include <linux/prefetch.h>
 #include <net/busy_poll.h>
 #include <linux/bpf_trace.h>
+#include <net/xdp.h>
 #include "i40e.h"
 #include "i40e_trace.h"
 #include "i40e_prototype.h"
@@ -1236,6 +1237,7 @@ void i40e_clean_rx_ring(struct i40e_ring *rx_ring)
 void i40e_free_rx_resources(struct i40e_ring *rx_ring)
 {
        i40e_clean_rx_ring(rx_ring);
+       xdp_rxq_info_unreg(&rx_ring->xdp_rxq);
        rx_ring->xdp_prog = NULL;
        kfree(rx_ring->rx_bi);
        rx_ring->rx_bi = NULL;
@@ -1283,6 +1285,18 @@ int i40e_setup_rx_descriptors(struct i40e_ring *rx_ring)
        rx_ring->next_to_clean = 0;
        rx_ring->next_to_use = 0;
 
+       /* XDP RX-queue info */
+       xdp_rxq_info_init(&rx_ring->xdp_rxq);
+
+       /* Flow director side channel does not invoke XDP/bpf */
+       if (rx_ring->vsi->type == I40E_VSI_FDIR)
+               xdp_rxq_info_type(&rx_ring->xdp_rxq, RXQ_TYPE_SINK);
+       else
+               rx_ring->xdp_rxq.dev = rx_ring->netdev;
+
+       rx_ring->xdp_rxq.queue_index = rx_ring->queue_index;
+       xdp_rxq_info_reg(&rx_ring->xdp_rxq);
+
        rx_ring->xdp_prog = rx_ring->vsi->xdp_prog;
 
        return 0;
@@ -2068,11 +2082,13 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, 
int budget)
        struct sk_buff *skb = rx_ring->skb;
        u16 cleaned_count = I40E_DESC_UNUSED(rx_ring);
        bool failure = false, xdp_xmit = false;
+       struct xdp_buff xdp;
+
+       xdp.rxq = &rx_ring->xdp_rxq;
 
        while (likely(total_rx_packets < (unsigned int)budget)) {
                struct i40e_rx_buffer *rx_buffer;
                union i40e_rx_desc *rx_desc;
-               struct xdp_buff xdp;
                unsigned int size;
                u16 vlan_tag;
                u8 rx_ptype;
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.h 
b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
index fbae1182e2ea..2d08760fc4ce 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
@@ -27,6 +27,8 @@
 #ifndef _I40E_TXRX_H_
 #define _I40E_TXRX_H_
 
+#include <net/xdp.h>
+
 /* Interrupt Throttling and Rate Limiting Goodies */
 
 #define I40E_MAX_ITR               0x0FF0  /* reg uses 2 usec resolution */
@@ -428,6 +430,7 @@ struct i40e_ring {
                                         */
 
        struct i40e_channel *ch;
+       struct xdp_rxq_info xdp_rxq;
 } ____cacheline_internodealigned_in_smp;
 
 static inline bool ring_uses_build_skb(struct i40e_ring *ring)