[Intel-wired-lan] [PATCH v3 0/9] igc: Add XDP support

[Intel-wired-lan] [PATCH v3 0/9] igc: Add XDP support

[Andre Guedes]

Hi all,

This is the third version of this series which adds XDP support to igc driver.

The main changes from v2 are:

    - Moved functions that belong to the driver's hot path to igc_main.c to
      allow the compiler to inline them if convenient.
    - Squashed ndo_xdp_xmit patch into XDP_REDIRECT patch.

v2 is here:

    https://patchwork.ozlabs.org/project/intel-wired-lan/cover/20201028201943.93147-1-andre.guedes at intel.com/

v1 is here:

    https://patchwork.ozlabs.org/project/intel-wired-lan/cover/20201009025349.4037-1-andre.guedes at intel.com/

Cheers,
Andre


Andre Guedes (9):
  igc: Fix igc_ptp_rx_pktstamp()
  igc: Remove unused argument from igc_tx_cmd_type()
  igc: Introduce igc_rx_buffer_flip() helper
  igc: Introduce igc_get_rx_frame_truesize() helper
  igc: Refactor rx timestamp handling
  igc: Add set/clear large buffer helpers
  igc: Add initial XDP support
  igc: Add support for XDP_TX action
  igc: Add support for XDP_REDIRECT action

 drivers/net/ethernet/intel/igc/Makefile   |   2 +-
 drivers/net/ethernet/intel/igc/igc.h      |  18 +-
 drivers/net/ethernet/intel/igc/igc_main.c | 431 +++++++++++++++++++---
 drivers/net/ethernet/intel/igc/igc_ptp.c  |  89 +++--
 drivers/net/ethernet/intel/igc/igc_xdp.c  |  60 +++
 drivers/net/ethernet/intel/igc/igc_xdp.h  |  13 +
 6 files changed, 512 insertions(+), 101 deletions(-)
 create mode 100644 drivers/net/ethernet/intel/igc/igc_xdp.c
 create mode 100644 drivers/net/ethernet/intel/igc/igc_xdp.h

-- 
2.28.0

[Intel-wired-lan] [PATCH v3 1/9] igc: Fix igc_ptp_rx_pktstamp()

[Andre Guedes]

The comment describing the timestamps layout in the packet buffer is
wrong and the code is actually retrieving the timestamp in Timer 1
reference instead of Timer 0. This hasn't been a big issue so far
because hardware is configured to report both timestamps using Timer 0
(see IGC_SRRCTL register configuration in igc_ptp_enable_rx_timestamp()
helper). This patch fixes the comment and the code so we retrieve the
timestamp in Timer 0 reference as expected.

This patch also takes the opportunity to get rid of the hw.mac.type check
since it is not required.

Fixes: 81b055205e8ba ("igc: Add support for RX timestamping")
Signed-off-by: Andre Guedes <andre.guedes@intel.com>
---
 drivers/net/ethernet/intel/igc/igc.h     |  2 +-
 drivers/net/ethernet/intel/igc/igc_ptp.c | 72 +++++++++++++-----------
 2 files changed, 41 insertions(+), 33 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
index 83d59b08e883..b66dda992d32 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -552,7 +552,7 @@ void igc_ptp_init(struct igc_adapter *adapter);
 void igc_ptp_reset(struct igc_adapter *adapter);
 void igc_ptp_suspend(struct igc_adapter *adapter);
 void igc_ptp_stop(struct igc_adapter *adapter);
-void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, void *va,
+void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, u32 *va,
 			 struct sk_buff *skb);
 int igc_ptp_set_ts_config(struct net_device *netdev, struct ifreq *ifr);
 int igc_ptp_get_ts_config(struct net_device *netdev, struct ifreq *ifr);
diff --git a/drivers/net/ethernet/intel/igc/igc_ptp.c b/drivers/net/ethernet/intel/igc/igc_ptp.c
index d73c4aaac610..79873f6df335 100644
--- a/drivers/net/ethernet/intel/igc/igc_ptp.c
+++ b/drivers/net/ethernet/intel/igc/igc_ptp.c
@@ -154,46 +154,54 @@ static void igc_ptp_systim_to_hwtstamp(struct igc_adapter *adapter,
 }
 
 /**
- * igc_ptp_rx_pktstamp - retrieve Rx per packet timestamp
+ * igc_ptp_rx_pktstamp - Retrieve timestamp from rx packet buffer
  * @q_vector: Pointer to interrupt specific structure
  * @va: Pointer to address containing Rx buffer
  * @skb: Buffer containing timestamp and packet
  *
- * This function is meant to retrieve the first timestamp from the
- * first buffer of an incoming frame. The value is stored in little
- * endian format starting on byte 0. There's a second timestamp
- * starting on byte 8.
- **/
-void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, void *va,
+ * This function retrieves the timestamp saved in the beginning of packet
+ * buffer. While two timestamps are available, one in timer0 reference and the
+ * other in timer1 reference, this function considers only the timestamp in
+ * timer0 reference.
+ */
+void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, u32 *va,
 			 struct sk_buff *skb)
 {
 	struct igc_adapter *adapter = q_vector->adapter;
-	__le64 *regval = (__le64 *)va;
-	int adjust = 0;
-
-	/* The timestamp is recorded in little endian format.
-	 * DWORD: | 0          | 1           | 2          | 3
-	 * Field: | Timer0 Low | Timer0 High | Timer1 Low | Timer1 High
+	u64 regval;
+	int adjust;
+
+	/* Timestamps are saved in little endian at the beginning of the packet
+	 * buffer following the layout:
+	 *
+	 * | 0              | 1              | 2              | 3              |
+	 * | Timer1 SYSTIML | Timer1 SYSTIMH | Timer0 SYSTIML | Timer0 SYSTIMH |
+	 *
+	 * SYSTIML holds the nanoseconds part while SYSTIMH holds the seconds
+	 * part of the timestamp.
 	 */
-	igc_ptp_systim_to_hwtstamp(adapter, skb_hwtstamps(skb),
-				   le64_to_cpu(regval[0]));
-
-	/* adjust timestamp for the RX latency based on link speed */
-	if (adapter->hw.mac.type == igc_i225) {
-		switch (adapter->link_speed) {
-		case SPEED_10:
-			adjust = IGC_I225_RX_LATENCY_10;
-			break;
-		case SPEED_100:
-			adjust = IGC_I225_RX_LATENCY_100;
-			break;
-		case SPEED_1000:
-			adjust = IGC_I225_RX_LATENCY_1000;
-			break;
-		case SPEED_2500:
-			adjust = IGC_I225_RX_LATENCY_2500;
-			break;
-		}
+	regval = le32_to_cpu(va[2]);
+	regval |= (u64)le32_to_cpu(va[3]) << 32;
+	igc_ptp_systim_to_hwtstamp(adapter, skb_hwtstamps(skb), regval);
+
+	/* Adjust timestamp for the RX latency based on link speed */
+	switch (adapter->link_speed) {
+	case SPEED_10:
+		adjust = IGC_I225_RX_LATENCY_10;
+		break;
+	case SPEED_100:
+		adjust = IGC_I225_RX_LATENCY_100;
+		break;
+	case SPEED_1000:
+		adjust = IGC_I225_RX_LATENCY_1000;
+		break;
+	case SPEED_2500:
+		adjust = IGC_I225_RX_LATENCY_2500;
+		break;
+	default:
+		adjust = 0;
+		netdev_warn_once(adapter->netdev, "Imprecise timestamp\n");
+		break;
 	}
 	skb_hwtstamps(skb)->hwtstamp =
 		ktime_sub_ns(skb_hwtstamps(skb)->hwtstamp, adjust);
-- 
2.28.0

[Intel-wired-lan] [PATCH v3 2/9] igc: Remove unused argument from igc_tx_cmd_type()

[Andre Guedes]

The 'skb' argument from igc_tx_cmd_type() is not used so this patch
removes it.

Signed-off-by: Andre Guedes <andre.guedes@intel.com>
---
 drivers/net/ethernet/intel/igc/igc_main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 240565aee2a3..5ce9253cca19 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -1042,7 +1042,7 @@ static inline int igc_maybe_stop_tx(struct igc_ring *tx_ring, const u16 size)
 	 ((u32)((_input) & (_flag)) * ((_result) / (_flag))) :	\
 	 ((u32)((_input) & (_flag)) / ((_flag) / (_result))))
 
-static u32 igc_tx_cmd_type(struct sk_buff *skb, u32 tx_flags)
+static u32 igc_tx_cmd_type(u32 tx_flags)
 {
 	/* set type for advanced descriptor with frame checksum insertion */
 	u32 cmd_type = IGC_ADVTXD_DTYP_DATA |
@@ -1091,7 +1091,7 @@ static int igc_tx_map(struct igc_ring *tx_ring,
 	u16 i = tx_ring->next_to_use;
 	unsigned int data_len, size;
 	dma_addr_t dma;
-	u32 cmd_type = igc_tx_cmd_type(skb, tx_flags);
+	u32 cmd_type = igc_tx_cmd_type(tx_flags);
 
 	tx_desc = IGC_TX_DESC(tx_ring, i);
 
-- 
2.28.0

[Intel-wired-lan] [PATCH v3 3/9] igc: Introduce igc_rx_buffer_flip() helper

[Andre Guedes]

The igc driver implements the same page recycling scheme from other
Intel drivers which reuses the page by flipping the buffer. The code
to handle buffer flips is duplicated in many locations so this patch
introduces the igc_rx_buffer_flip() helper and uses it where applicable.

Signed-off-by: Andre Guedes <andre.guedes@intel.com>
---
 drivers/net/ethernet/intel/igc/igc_main.c | 42 +++++++++++------------
 1 file changed, 20 insertions(+), 22 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 5ce9253cca19..31dc58a82cf3 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -1513,6 +1513,16 @@ static struct igc_rx_buffer *igc_get_rx_buffer(struct igc_ring *rx_ring,
 	return rx_buffer;
 }
 
+static void igc_rx_buffer_flip(struct igc_rx_buffer *buffer,
+			       unsigned int truesize)
+{
+#if (PAGE_SIZE < 8192)
+	buffer->page_offset ^= truesize;
+#else
+	buffer->page_offset += truesize;
+#endif
+}
+
 /**
  * igc_add_rx_frag - Add contents of Rx buffer to sk_buff
  * @rx_ring: rx descriptor ring to transact packets on
@@ -1527,20 +1537,18 @@ static void igc_add_rx_frag(struct igc_ring *rx_ring,
 			    struct sk_buff *skb,
 			    unsigned int size)
 {
+	unsigned int truesize;
 #if (PAGE_SIZE < 8192)
-	unsigned int truesize = igc_rx_pg_size(rx_ring) / 2;
-
-	skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_buffer->page,
-			rx_buffer->page_offset, size, truesize);
-	rx_buffer->page_offset ^= truesize;
+	truesize = igc_rx_pg_size(rx_ring) / 2;
 #else
-	unsigned int truesize = ring_uses_build_skb(rx_ring) ?
-				SKB_DATA_ALIGN(IGC_SKB_PAD + size) :
-				SKB_DATA_ALIGN(size);
+	truesize = ring_uses_build_skb(rx_ring) ?
+		   SKB_DATA_ALIGN(IGC_SKB_PAD + size) :
+		   SKB_DATA_ALIGN(size);
+#endif
 	skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_buffer->page,
 			rx_buffer->page_offset, size, truesize);
-	rx_buffer->page_offset += truesize;
-#endif
+
+	igc_rx_buffer_flip(rx_buffer, truesize);
 }
 
 static struct sk_buff *igc_build_skb(struct igc_ring *rx_ring,
@@ -1569,13 +1577,7 @@ static struct sk_buff *igc_build_skb(struct igc_ring *rx_ring,
 	skb_reserve(skb, IGC_SKB_PAD);
 	__skb_put(skb, size);
 
-	/* update buffer offset */
-#if (PAGE_SIZE < 8192)
-	rx_buffer->page_offset ^= truesize;
-#else
-	rx_buffer->page_offset += truesize;
-#endif
-
+	igc_rx_buffer_flip(rx_buffer, truesize);
 	return skb;
 }
 
@@ -1621,11 +1623,7 @@ static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring,
 		skb_add_rx_frag(skb, 0, rx_buffer->page,
 				(va + headlen) - page_address(rx_buffer->page),
 				size, truesize);
-#if (PAGE_SIZE < 8192)
-		rx_buffer->page_offset ^= truesize;
-#else
-		rx_buffer->page_offset += truesize;
-#endif
+		igc_rx_buffer_flip(rx_buffer, truesize);
 	} else {
 		rx_buffer->pagecnt_bias++;
 	}
-- 
2.28.0

[Intel-wired-lan] [PATCH v3 4/9] igc: Introduce igc_get_rx_frame_truesize() helper

[Andre Guedes]

The RX frame truesize calculation is scattered throughout the RX code.
This patch creates the helper function igc_get_rx_frame_truesize() and
uses it where applicable.

Signed-off-by: Andre Guedes <andre.guedes@intel.com>
---
 drivers/net/ethernet/intel/igc/igc_main.c | 29 ++++++++++++++---------
 1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 31dc58a82cf3..15c67e5763d3 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -1523,6 +1523,22 @@ static void igc_rx_buffer_flip(struct igc_rx_buffer *buffer,
 #endif
 }
 
+static unsigned int igc_get_rx_frame_truesize(struct igc_ring *ring,
+					      unsigned int size)
+{
+	unsigned int truesize;
+
+#if (PAGE_SIZE < 8192)
+	truesize = igc_rx_pg_size(ring) / 2;
+#else
+	truesize = ring_uses_build_skb(ring) ?
+		   SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) +
+		   SKB_DATA_ALIGN(IGC_SKB_PAD + size) :
+		   SKB_DATA_ALIGN(size);
+#endif
+	return truesize;
+}
+
 /**
  * igc_add_rx_frag - Add contents of Rx buffer to sk_buff
  * @rx_ring: rx descriptor ring to transact packets on
@@ -1557,12 +1573,7 @@ static struct sk_buff *igc_build_skb(struct igc_ring *rx_ring,
 				     unsigned int size)
 {
 	void *va = page_address(rx_buffer->page) + rx_buffer->page_offset;
-#if (PAGE_SIZE < 8192)
-	unsigned int truesize = igc_rx_pg_size(rx_ring) / 2;
-#else
-	unsigned int truesize = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) +
-				SKB_DATA_ALIGN(IGC_SKB_PAD + size);
-#endif
+	unsigned int truesize = igc_get_rx_frame_truesize(rx_ring, size);
 	struct sk_buff *skb;
 
 	/* prefetch first cache line of first page */
@@ -1587,11 +1598,7 @@ static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring,
 					 unsigned int size)
 {
 	void *va = page_address(rx_buffer->page) + rx_buffer->page_offset;
-#if (PAGE_SIZE < 8192)
-	unsigned int truesize = igc_rx_pg_size(rx_ring) / 2;
-#else
-	unsigned int truesize = SKB_DATA_ALIGN(size);
-#endif
+	unsigned int truesize = igc_get_rx_frame_truesize(rx_ring, size);
 	unsigned int headlen;
 	struct sk_buff *skb;
 
-- 
2.28.0

[Intel-wired-lan] [PATCH v3 5/9] igc: Refactor rx timestamp handling

[Andre Guedes]

This patch refactors the rx timestamp handling in preparation to land
XDP support.

RX timestamps are put in the rx buffer by hardware, before the packet
data. When creating the xdp buffer, we will need to check the rx
descriptor to determine if the buffer contains timestamp information
and consider the offset when setting xdp.data.

The rx descriptor check is already done in igc_construct_skb(). To
avoid code duplication, this patch moves the timestamp handling to
igc_clean_rx_irq() so both skb and xdp paths can reuse it.

Signed-off-by: Andre Guedes <andre.guedes@intel.com>
---
 drivers/net/ethernet/intel/igc/igc.h      |  3 +--
 drivers/net/ethernet/intel/igc/igc_main.c | 30 +++++++++++++++--------
 drivers/net/ethernet/intel/igc/igc_ptp.c  | 25 ++++++++++---------
 3 files changed, 34 insertions(+), 24 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
index b66dda992d32..ae91d51073ca 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -552,8 +552,7 @@ void igc_ptp_init(struct igc_adapter *adapter);
 void igc_ptp_reset(struct igc_adapter *adapter);
 void igc_ptp_suspend(struct igc_adapter *adapter);
 void igc_ptp_stop(struct igc_adapter *adapter);
-void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, u32 *va,
-			 struct sk_buff *skb);
+ktime_t igc_ptp_rx_pktstamp(struct igc_adapter *adapter, u32 *buf);
 int igc_ptp_set_ts_config(struct net_device *netdev, struct ifreq *ifr);
 int igc_ptp_get_ts_config(struct net_device *netdev, struct ifreq *ifr);
 void igc_ptp_tx_hang(struct igc_adapter *adapter);
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 15c67e5763d3..84ffde75e968 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -1594,10 +1594,11 @@ static struct sk_buff *igc_build_skb(struct igc_ring *rx_ring,
 
 static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring,
 					 struct igc_rx_buffer *rx_buffer,
-					 union igc_adv_rx_desc *rx_desc,
-					 unsigned int size)
+					 unsigned int size, int pkt_offset,
+					 ktime_t timestamp)
 {
-	void *va = page_address(rx_buffer->page) + rx_buffer->page_offset;
+	void *va = page_address(rx_buffer->page) + rx_buffer->page_offset +
+		   pkt_offset;
 	unsigned int truesize = igc_get_rx_frame_truesize(rx_ring, size);
 	unsigned int headlen;
 	struct sk_buff *skb;
@@ -1610,11 +1611,8 @@ static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring,
 	if (unlikely(!skb))
 		return NULL;
 
-	if (unlikely(igc_test_staterr(rx_desc, IGC_RXDADV_STAT_TSIP))) {
-		igc_ptp_rx_pktstamp(rx_ring->q_vector, va, skb);
-		va += IGC_TS_HDR_LEN;
-		size -= IGC_TS_HDR_LEN;
-	}
+	if (timestamp)
+		skb_hwtstamps(skb)->hwtstamp = timestamp;
 
 	/* Determine available headroom for copy */
 	headlen = size;
@@ -1913,6 +1911,8 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
 	while (likely(total_packets < budget)) {
 		union igc_adv_rx_desc *rx_desc;
 		struct igc_rx_buffer *rx_buffer;
+		ktime_t timestamp = 0;
+		int pkt_offset = 0;
 		unsigned int size;
 
 		/* return some buffers to hardware, one@a time is too slow */
@@ -1934,14 +1934,24 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
 
 		rx_buffer = igc_get_rx_buffer(rx_ring, size);
 
+		if (igc_test_staterr(rx_desc, IGC_RXDADV_STAT_TSIP)) {
+			void *pktbuf = page_address(rx_buffer->page) +
+				       rx_buffer->page_offset;
+
+			timestamp = igc_ptp_rx_pktstamp(q_vector->adapter,
+							pktbuf);
+			pkt_offset = IGC_TS_HDR_LEN;
+			size -= IGC_TS_HDR_LEN;
+		}
+
 		/* retrieve a buffer from the ring */
 		if (skb)
 			igc_add_rx_frag(rx_ring, rx_buffer, skb, size);
 		else if (ring_uses_build_skb(rx_ring))
 			skb = igc_build_skb(rx_ring, rx_buffer, rx_desc, size);
 		else
-			skb = igc_construct_skb(rx_ring, rx_buffer,
-						rx_desc, size);
+			skb = igc_construct_skb(rx_ring, rx_buffer, size,
+						pkt_offset, timestamp);
 
 		/* exit if we failed to retrieve a buffer */
 		if (!skb) {
diff --git a/drivers/net/ethernet/intel/igc/igc_ptp.c b/drivers/net/ethernet/intel/igc/igc_ptp.c
index 79873f6df335..4331c2dcffb2 100644
--- a/drivers/net/ethernet/intel/igc/igc_ptp.c
+++ b/drivers/net/ethernet/intel/igc/igc_ptp.c
@@ -155,20 +155,20 @@ static void igc_ptp_systim_to_hwtstamp(struct igc_adapter *adapter,
 
 /**
  * igc_ptp_rx_pktstamp - Retrieve timestamp from rx packet buffer
- * @q_vector: Pointer to interrupt specific structure
- * @va: Pointer to address containing Rx buffer
- * @skb: Buffer containing timestamp and packet
+ * @adapter: Pointer to adapter the packet buffer belongs to
+ * @buf: Pointer to packet buffer
  *
  * This function retrieves the timestamp saved in the beginning of packet
  * buffer. While two timestamps are available, one in timer0 reference and the
  * other in timer1 reference, this function considers only the timestamp in
  * timer0 reference.
+ *
+ * Returns: Timestamp value.
  */
-void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, u32 *va,
-			 struct sk_buff *skb)
+ktime_t igc_ptp_rx_pktstamp(struct igc_adapter *adapter, u32 *buf)
 {
-	struct igc_adapter *adapter = q_vector->adapter;
-	u64 regval;
+	ktime_t timestamp;
+	u32 secs, nsecs;
 	int adjust;
 
 	/* Timestamps are saved in little endian at the beginning of the packet
@@ -180,9 +180,10 @@ void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, u32 *va,
 	 * SYSTIML holds the nanoseconds part while SYSTIMH holds the seconds
 	 * part of the timestamp.
 	 */
-	regval = le32_to_cpu(va[2]);
-	regval |= (u64)le32_to_cpu(va[3]) << 32;
-	igc_ptp_systim_to_hwtstamp(adapter, skb_hwtstamps(skb), regval);
+	nsecs = le32_to_cpu(buf[2]);
+	secs = le32_to_cpu(buf[3]);
+
+	timestamp = ktime_set(secs, nsecs);
 
 	/* Adjust timestamp for the RX latency based on link speed */
 	switch (adapter->link_speed) {
@@ -203,8 +204,8 @@ void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, u32 *va,
 		netdev_warn_once(adapter->netdev, "Imprecise timestamp\n");
 		break;
 	}
-	skb_hwtstamps(skb)->hwtstamp =
-		ktime_sub_ns(skb_hwtstamps(skb)->hwtstamp, adjust);
+
+	return ktime_sub_ns(timestamp, adjust);
 }
 
 static void igc_ptp_disable_rx_timestamp(struct igc_adapter *adapter)
-- 
2.28.0

[Intel-wired-lan] [PATCH v3 6/9] igc: Add set/clear large buffer helpers

[Andre Guedes]

While commit 13b5b7fd6a4a ("igc: Add support for Tx/Rx rings")
introduced code to handle larger packet buffers, it missed the
set/clear helpers which enable/disable that feature. This patch
introduces the missing helpers which will be use in the next
patch.

Signed-off-by: Andre Guedes <andre.guedes@intel.com>
---
 drivers/net/ethernet/intel/igc/igc.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
index ae91d51073ca..e72f1fc772aa 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -509,6 +509,10 @@ enum igc_ring_flags_t {
 
 #define ring_uses_large_buffer(ring) \
 	test_bit(IGC_RING_FLAG_RX_3K_BUFFER, &(ring)->flags)
+#define set_ring_uses_large_buffer(ring) \
+	set_bit(IGC_RING_FLAG_RX_3K_BUFFER, &(ring)->flags)
+#define clear_ring_uses_large_buffer(ring) \
+	clear_bit(IGC_RING_FLAG_RX_3K_BUFFER, &(ring)->flags)
 
 #define ring_uses_build_skb(ring) \
 	test_bit(IGC_RING_FLAG_RX_BUILD_SKB_ENABLED, &(ring)->flags)
-- 
2.28.0

[Intel-wired-lan] [PATCH v3 7/9] igc: Add initial XDP support

[Andre Guedes]

This patch adds the initial XDP support to the igc driver. For now,
only XDP_PASS, XDP_DROP, XDP_ABORTED actions are supported. Upcoming
patches will add support for the remaining XDP actions.

XDP configuration helpers are defined in a new file, igc_xdp.c. These
helpers are utilized in igc_main.c to implement the ndo_bpf callback.
XDP-related code that belongs to the driver's hot path is landed in
igc_main.c.

By default, the driver uses rx buffers with 2 KB size. When XDP is
enabled, it uses larger buffers so we have enough space to accommodate
the headroom and tailroom required by XDP infrastructure. Also, the
driver doesn't support XDP functionality with frames that span over
multiple buffers so jumbo frames are not allowed for now.

The approach implemented by this patch follows the approach implemented
in other Intel drivers as much as possible for the sake of consistency
across the drivers.

Quick comment regarding igc_build_skb(): this patch doesn't touch it
because the function is never called. It seems its support is
incomplete/in progress. The function was added by commit 0507ef8a0372b
("igc: Add transmit and receive fastpath and interrupt handlers") but
ring_uses_build_skb() always return False since the IGC_RING_FLAG_RX_
BUILD_SKB_ENABLED isn't set anywhere in the driver code.

This patch has been tested with the sample app "xdp1" located in
samples/bpf/ dir.

Signed-off-by: Andre Guedes <andre.guedes@intel.com>
---
 drivers/net/ethernet/intel/igc/Makefile   |   2 +-
 drivers/net/ethernet/intel/igc/igc.h      |   2 +
 drivers/net/ethernet/intel/igc/igc_main.c | 118 ++++++++++++++++++++--
 drivers/net/ethernet/intel/igc/igc_xdp.c  |  33 ++++++
 drivers/net/ethernet/intel/igc/igc_xdp.h  |  10 ++
 5 files changed, 153 insertions(+), 12 deletions(-)
 create mode 100644 drivers/net/ethernet/intel/igc/igc_xdp.c
 create mode 100644 drivers/net/ethernet/intel/igc/igc_xdp.h

diff --git a/drivers/net/ethernet/intel/igc/Makefile b/drivers/net/ethernet/intel/igc/Makefile
index 1c3051db9085..95d1e8c490a4 100644
--- a/drivers/net/ethernet/intel/igc/Makefile
+++ b/drivers/net/ethernet/intel/igc/Makefile
@@ -8,4 +8,4 @@
 obj-$(CONFIG_IGC) += igc.o
 
 igc-objs := igc_main.o igc_mac.o igc_i225.o igc_base.o igc_nvm.o igc_phy.o \
-igc_diag.o igc_ethtool.o igc_ptp.o igc_dump.o igc_tsn.o
+igc_diag.o igc_ethtool.o igc_ptp.o igc_dump.o igc_tsn.o igc_xdp.o
diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
index e72f1fc772aa..5c2f363106ae 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -224,6 +224,8 @@ struct igc_adapter {
 	struct mutex ptm_time_lock; /* protects host and device timestamps */
 	ktime_t ptm_device_time;
 	struct system_counterval_t ptm_host_time;
+
+	struct bpf_prog *xdp_prog;
 };
 
 void igc_up(struct igc_adapter *adapter);
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 84ffde75e968..734a570bbadb 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -11,17 +11,22 @@
 #include <linux/pm_runtime.h>
 #include <net/pkt_sched.h>
 #include <linux/pci.h>
+#include <linux/bpf_trace.h>
 
 #include <net/ipv6.h>
 
 #include "igc.h"
 #include "igc_hw.h"
 #include "igc_tsn.h"
+#include "igc_xdp.h"
 
 #define DRV_SUMMARY	"Intel(R) 2.5G Ethernet Linux Driver"
 
 #define DEFAULT_MSG_ENABLE (NETIF_MSG_DRV | NETIF_MSG_PROBE | NETIF_MSG_LINK)
 
+#define IGC_XDP_PASS		0
+#define IGC_XDP_CONSUMED	BIT(0)
+
 static int debug = -1;
 
 MODULE_AUTHOR("Intel Corporation, <linux.nics@intel.com>");
@@ -346,6 +351,8 @@ static void igc_clean_rx_ring(struct igc_ring *rx_ring)
 {
 	u16 i = rx_ring->next_to_clean;
 
+	clear_ring_uses_large_buffer(rx_ring);
+
 	dev_kfree_skb(rx_ring->skb);
 	rx_ring->skb = NULL;
 
@@ -498,6 +505,11 @@ static int igc_setup_all_rx_resources(struct igc_adapter *adapter)
 	return err;
 }
 
+static bool igc_xdp_is_enabled(struct igc_adapter *adapter)
+{
+	return !!adapter->xdp_prog;
+}
+
 /**
  * igc_configure_rx_ring - Configure a receive ring after Reset
  * @adapter: board private structure
@@ -514,6 +526,9 @@ static void igc_configure_rx_ring(struct igc_adapter *adapter,
 	u32 srrctl = 0, rxdctl = 0;
 	u64 rdba = ring->dma;
 
+	if (igc_xdp_is_enabled(adapter))
+		set_ring_uses_large_buffer(ring);
+
 	/* disable the queue */
 	wr32(IGC_RXDCTL(reg_idx), 0);
 
@@ -1594,12 +1609,12 @@ static struct sk_buff *igc_build_skb(struct igc_ring *rx_ring,
 
 static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring,
 					 struct igc_rx_buffer *rx_buffer,
-					 unsigned int size, int pkt_offset,
+					 struct xdp_buff *xdp,
 					 ktime_t timestamp)
 {
-	void *va = page_address(rx_buffer->page) + rx_buffer->page_offset +
-		   pkt_offset;
+	unsigned int size = xdp->data_end - xdp->data;
 	unsigned int truesize = igc_get_rx_frame_truesize(rx_ring, size);
+	void *va = xdp->data;
 	unsigned int headlen;
 	struct sk_buff *skb;
 
@@ -1748,6 +1763,10 @@ static bool igc_cleanup_headers(struct igc_ring *rx_ring,
 				union igc_adv_rx_desc *rx_desc,
 				struct sk_buff *skb)
 {
+	/* XDP packets use error pointer so abort at this point */
+	if (IS_ERR(skb))
+		return true;
+
 	if (unlikely(igc_test_staterr(rx_desc, IGC_RXDEXT_STATERR_RXE))) {
 		struct net_device *netdev = rx_ring->netdev;
 
@@ -1787,7 +1806,14 @@ static void igc_put_rx_buffer(struct igc_ring *rx_ring,
 
 static inline unsigned int igc_rx_offset(struct igc_ring *rx_ring)
 {
-	return ring_uses_build_skb(rx_ring) ? IGC_SKB_PAD : 0;
+	struct igc_adapter *adapter = rx_ring->q_vector->adapter;
+
+	if (ring_uses_build_skb(rx_ring))
+		return IGC_SKB_PAD;
+	if (igc_xdp_is_enabled(adapter))
+		return XDP_PACKET_HEADROOM;
+
+	return 0;
 }
 
 static bool igc_alloc_mapped_page(struct igc_ring *rx_ring,
@@ -1901,6 +1927,42 @@ static void igc_alloc_rx_buffers(struct igc_ring *rx_ring, u16 cleaned_count)
 	}
 }
 
+static struct sk_buff *igc_xdp_run_prog(struct igc_adapter *adapter,
+					struct xdp_buff *xdp)
+{
+	struct bpf_prog *prog;
+	int res;
+	u32 act;
+
+	rcu_read_lock();
+
+	prog = READ_ONCE(adapter->xdp_prog);
+	if (!prog) {
+		res = IGC_XDP_PASS;
+		goto unlock;
+	}
+
+	act = bpf_prog_run_xdp(prog, xdp);
+	switch (act) {
+	case XDP_PASS:
+		res = IGC_XDP_PASS;
+		break;
+	default:
+		bpf_warn_invalid_xdp_action(act);
+		fallthrough;
+	case XDP_ABORTED:
+		trace_xdp_exception(adapter->netdev, prog, act);
+		fallthrough;
+	case XDP_DROP:
+		res = IGC_XDP_CONSUMED;
+		break;
+	}
+
+unlock:
+	rcu_read_unlock();
+	return ERR_PTR(-res);
+}
+
 static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
 {
 	unsigned int total_bytes = 0, total_packets = 0;
@@ -1912,8 +1974,10 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
 		union igc_adv_rx_desc *rx_desc;
 		struct igc_rx_buffer *rx_buffer;
 		ktime_t timestamp = 0;
+		struct xdp_buff xdp;
 		int pkt_offset = 0;
 		unsigned int size;
+		void *pktbuf;
 
 		/* return some buffers to hardware, one at a time is too slow */
 		if (cleaned_count >= IGC_RX_BUFFER_WRITE) {
@@ -1934,24 +1998,38 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
 
 		rx_buffer = igc_get_rx_buffer(rx_ring, size);
 
-		if (igc_test_staterr(rx_desc, IGC_RXDADV_STAT_TSIP)) {
-			void *pktbuf = page_address(rx_buffer->page) +
-				       rx_buffer->page_offset;
+		pktbuf = page_address(rx_buffer->page) + rx_buffer->page_offset;
 
+		if (igc_test_staterr(rx_desc, IGC_RXDADV_STAT_TSIP)) {
 			timestamp = igc_ptp_rx_pktstamp(q_vector->adapter,
 							pktbuf);
 			pkt_offset = IGC_TS_HDR_LEN;
 			size -= IGC_TS_HDR_LEN;
 		}
 
-		/* retrieve a buffer from the ring */
-		if (skb)
+		if (!skb) {
+			struct igc_adapter *adapter = q_vector->adapter;
+
+			xdp.data = pktbuf + pkt_offset;
+			xdp.data_end = xdp.data + size;
+			xdp.data_hard_start = pktbuf - igc_rx_offset(rx_ring);
+			xdp_set_data_meta_invalid(&xdp);
+			xdp.frame_sz = igc_get_rx_frame_truesize(rx_ring, size);
+
+			skb = igc_xdp_run_prog(adapter, &xdp);
+		}
+
+		if (IS_ERR(skb)) {
+			rx_buffer->pagecnt_bias++;
+			total_packets++;
+			total_bytes += size;
+		} else if (skb)
 			igc_add_rx_frag(rx_ring, rx_buffer, skb, size);
 		else if (ring_uses_build_skb(rx_ring))
 			skb = igc_build_skb(rx_ring, rx_buffer, rx_desc, size);
 		else
-			skb = igc_construct_skb(rx_ring, rx_buffer, size,
-						pkt_offset, timestamp);
+			skb = igc_construct_skb(rx_ring, rx_buffer, &xdp,
+						timestamp);
 
 		/* exit if we failed to retrieve a buffer */
 		if (!skb) {
@@ -3893,6 +3971,11 @@ static int igc_change_mtu(struct net_device *netdev, int new_mtu)
 	int max_frame = new_mtu + ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN;
 	struct igc_adapter *adapter = netdev_priv(netdev);
 
+	if (igc_xdp_is_enabled(adapter) && new_mtu > ETH_DATA_LEN) {
+		netdev_dbg(netdev, "Jumbo frames not supported with XDP");
+		return -EINVAL;
+	}
+
 	/* adjust max frame to be at least the size of a standard frame */
 	if (max_frame < (ETH_FRAME_LEN + ETH_FCS_LEN))
 		max_frame = ETH_FRAME_LEN + ETH_FCS_LEN;
@@ -4881,6 +4964,18 @@ static int igc_setup_tc(struct net_device *dev, enum tc_setup_type type,
 	}
 }
 
+static int igc_bpf(struct net_device *dev, struct netdev_bpf *bpf)
+{
+	struct igc_adapter *adapter = netdev_priv(dev);
+
+	switch (bpf->command) {
+	case XDP_SETUP_PROG:
+		return igc_xdp_set_prog(adapter, bpf->prog, bpf->extack);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
 static const struct net_device_ops igc_netdev_ops = {
 	.ndo_open		= igc_open,
 	.ndo_stop		= igc_close,
@@ -4894,6 +4989,7 @@ static const struct net_device_ops igc_netdev_ops = {
 	.ndo_features_check	= igc_features_check,
 	.ndo_do_ioctl		= igc_ioctl,
 	.ndo_setup_tc		= igc_setup_tc,
+	.ndo_bpf		= igc_bpf,
 };
 
 /* PCIe configuration access */
diff --git a/drivers/net/ethernet/intel/igc/igc_xdp.c b/drivers/net/ethernet/intel/igc/igc_xdp.c
new file mode 100644
index 000000000000..27c886a254f1
--- /dev/null
+++ b/drivers/net/ethernet/intel/igc/igc_xdp.c
@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020, Intel Corporation. */
+
+#include "igc.h"
+#include "igc_xdp.h"
+
+int igc_xdp_set_prog(struct igc_adapter *adapter, struct bpf_prog *prog,
+		     struct netlink_ext_ack *extack)
+{
+	struct net_device *dev = adapter->netdev;
+	bool if_running = netif_running(dev);
+	struct bpf_prog *old_prog;
+
+	if (dev->mtu > ETH_DATA_LEN) {
+		/* For now, the driver doesn't support XDP functionality with
+		 * jumbo frames so we return error.
+		 */
+		NL_SET_ERR_MSG_MOD(extack, "Jumbo frames not supported");
+		return -EOPNOTSUPP;
+	}
+
+	if (if_running)
+		igc_close(dev);
+
+	old_prog = xchg(&adapter->xdp_prog, prog);
+	if (old_prog)
+		bpf_prog_put(old_prog);
+
+	if (if_running)
+		igc_open(dev);
+
+	return 0;
+}
diff --git a/drivers/net/ethernet/intel/igc/igc_xdp.h b/drivers/net/ethernet/intel/igc/igc_xdp.h
new file mode 100644
index 000000000000..8a410bcefe1a
--- /dev/null
+++ b/drivers/net/ethernet/intel/igc/igc_xdp.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2020, Intel Corporation. */
+
+#ifndef _IGC_XDP_H_
+#define _IGC_XDP_H_
+
+int igc_xdp_set_prog(struct igc_adapter *adapter, struct bpf_prog *prog,
+		     struct netlink_ext_ack *extack);
+
+#endif /* _IGC_XDP_H_ */
-- 
2.28.0

[Intel-wired-lan] [PATCH v3 8/9] igc: Add support for XDP_TX action

[Andre Guedes]

This patch adds support for XDP_TX action which enables XDP programs to
transmit back receiving frames.

I225 controller has only 4 tx hardware queues. Since XDP programs may
not even issue an XDP_TX action, this patch doesn't reserve dedicated
queues just for XDP like other Intel drivers do. Instead, the queues
are shared between the network stack and XDP. The netdev queue lock is
used to ensure mutual exclusion.

Since frames can now be transmitted via XDP_TX, the igc_tx_buffer
structure is modified so we are able to save a reference to the xdp
frame for later clean up once the packet is transmitted. The tx_buffer
is mapped to either a skb or a xdpf so we use a union to save the skb
or xdpf pointer and have a bit in tx_flags to indicate which field to
use.

This patch has been tested with the sample app "xdp2" located in
samples/bpf/ dir.

Signed-off-by: Andre Guedes <andre.guedes@intel.com>
---
 drivers/net/ethernet/intel/igc/igc.h      |   9 +-
 drivers/net/ethernet/intel/igc/igc_main.c | 173 ++++++++++++++++++++--
 drivers/net/ethernet/intel/igc/igc_xdp.c  |  27 ++++
 drivers/net/ethernet/intel/igc/igc_xdp.h  |   3 +
 4 files changed, 201 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
index 5c2f363106ae..9c566d930ab0 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -112,6 +112,8 @@ struct igc_ring {
 			struct sk_buff *skb;
 		};
 	};
+
+	struct xdp_rxq_info xdp_rxq;
 } ____cacheline_internodealigned_in_smp;
 
 /* Board specific private data structure */
@@ -380,6 +382,8 @@ enum igc_tx_flags {
 	/* olinfo flags */
 	IGC_TX_FLAGS_IPV4	= 0x10,
 	IGC_TX_FLAGS_CSUM	= 0x20,
+
+	IGC_TX_FLAGS_XDP	= 0x100,
 };
 
 enum igc_boards {
@@ -402,7 +406,10 @@ enum igc_boards {
 struct igc_tx_buffer {
 	union igc_adv_tx_desc *next_to_watch;
 	unsigned long time_stamp;
-	struct sk_buff *skb;
+	union {
+		struct sk_buff *skb;
+		struct xdp_frame *xdpf;
+	};
 	unsigned int bytecount;
 	u16 gso_segs;
 	__be16 protocol;
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index 734a570bbadb..ae933982e239 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -26,6 +26,7 @@
 
 #define IGC_XDP_PASS		0
 #define IGC_XDP_CONSUMED	BIT(0)
+#define IGC_XDP_TX		BIT(1)
 
 static int debug = -1;
 
@@ -182,8 +183,10 @@ static void igc_clean_tx_ring(struct igc_ring *tx_ring)
 	while (i != tx_ring->next_to_use) {
 		union igc_adv_tx_desc *eop_desc, *tx_desc;
 
-		/* Free all the Tx ring sk_buffs */
-		dev_kfree_skb_any(tx_buffer->skb);
+		if (tx_buffer->tx_flags & IGC_TX_FLAGS_XDP)
+			xdp_return_frame(tx_buffer->xdpf);
+		else
+			dev_kfree_skb_any(tx_buffer->skb);
 
 		/* unmap skb header data */
 		dma_unmap_single(tx_ring->dev,
@@ -411,6 +414,8 @@ void igc_free_rx_resources(struct igc_ring *rx_ring)
 {
 	igc_clean_rx_ring(rx_ring);
 
+	igc_xdp_unregister_rxq_info(rx_ring);
+
 	vfree(rx_ring->rx_buffer_info);
 	rx_ring->rx_buffer_info = NULL;
 
@@ -448,7 +453,11 @@ int igc_setup_rx_resources(struct igc_ring *rx_ring)
 {
 	struct net_device *ndev = rx_ring->netdev;
 	struct device *dev = rx_ring->dev;
-	int size, desc_len;
+	int size, desc_len, res;
+
+	res = igc_xdp_register_rxq_info(rx_ring);
+	if (res < 0)
+		return res;
 
 	size = sizeof(struct igc_rx_buffer) * rx_ring->count;
 	rx_ring->rx_buffer_info = vzalloc(size);
@@ -474,6 +483,7 @@ int igc_setup_rx_resources(struct igc_ring *rx_ring)
 	return 0;
 
 err:
+	igc_xdp_unregister_rxq_info(rx_ring);
 	vfree(rx_ring->rx_buffer_info);
 	rx_ring->rx_buffer_info = NULL;
 	netdev_err(ndev, "Unable to allocate memory for Rx descriptor ring\n");
@@ -1927,6 +1937,98 @@ static void igc_alloc_rx_buffers(struct igc_ring *rx_ring, u16 cleaned_count)
 	}
 }
 
+static int igc_xdp_init_tx_buffer(struct igc_tx_buffer *buffer,
+				  struct xdp_frame *xdpf,
+				  struct igc_ring *ring)
+{
+	dma_addr_t dma;
+
+	dma = dma_map_single(ring->dev, xdpf->data, xdpf->len, DMA_TO_DEVICE);
+	if (dma_mapping_error(ring->dev, dma)) {
+		netdev_err_once(ring->netdev, "Failed to map DMA for TX\n");
+		return -ENOMEM;
+	}
+
+	buffer->xdpf = xdpf;
+	buffer->tx_flags = IGC_TX_FLAGS_XDP;
+	buffer->protocol = 0;
+	buffer->bytecount = xdpf->len;
+	buffer->gso_segs = 1;
+	buffer->time_stamp = jiffies;
+	dma_unmap_len_set(buffer, len, xdpf->len);
+	dma_unmap_addr_set(buffer, dma, dma);
+	return 0;
+}
+
+/* This function requires __netif_tx_lock is held by the caller. */
+static int igc_xdp_init_tx_descriptor(struct igc_ring *ring,
+				      struct xdp_frame *xdpf)
+{
+	struct igc_tx_buffer *buffer;
+	union igc_adv_tx_desc *desc;
+	u32 cmd_type, olinfo_status;
+	int err;
+
+	if (!igc_desc_unused(ring))
+		return -EBUSY;
+
+	buffer = &ring->tx_buffer_info[ring->next_to_use];
+	err = igc_xdp_init_tx_buffer(buffer, xdpf, ring);
+	if (err)
+		return err;
+
+	cmd_type = IGC_ADVTXD_DTYP_DATA | IGC_ADVTXD_DCMD_DEXT |
+		   IGC_ADVTXD_DCMD_IFCS | IGC_TXD_DCMD |
+		   buffer->bytecount;
+	olinfo_status = buffer->bytecount << IGC_ADVTXD_PAYLEN_SHIFT;
+
+	desc = IGC_TX_DESC(ring, ring->next_to_use);
+	desc->read.cmd_type_len = cpu_to_le32(cmd_type);
+	desc->read.olinfo_status = cpu_to_le32(olinfo_status);
+	desc->read.buffer_addr = cpu_to_le64(dma_unmap_addr(buffer, dma));
+
+	netdev_tx_sent_queue(txring_txq(ring), buffer->bytecount);
+
+	buffer->next_to_watch = desc;
+
+	ring->next_to_use++;
+	if (ring->next_to_use == ring->count)
+		ring->next_to_use = 0;
+
+	return 0;
+}
+
+static struct igc_ring *igc_xdp_get_tx_ring(struct igc_adapter *adapter,
+					    int cpu)
+{
+	int index = cpu;
+
+	if (index >= adapter->num_tx_queues)
+		index = index % adapter->num_tx_queues;
+
+	return adapter->tx_ring[index];
+}
+
+static int igc_xdp_xmit_back(struct igc_adapter *adapter, struct xdp_buff *xdp)
+{
+	struct xdp_frame *xdpf = xdp_convert_buff_to_frame(xdp);
+	int cpu = smp_processor_id();
+	struct netdev_queue *nq;
+	struct igc_ring *ring;
+	int res;
+
+	if (unlikely(!xdpf))
+		return -EFAULT;
+
+	ring = igc_xdp_get_tx_ring(adapter, cpu);
+	nq = txring_txq(ring);
+
+	__netif_tx_lock(nq, cpu);
+	res = igc_xdp_init_tx_descriptor(ring, xdpf);
+	__netif_tx_unlock(nq);
+	return res;
+}
+
 static struct sk_buff *igc_xdp_run_prog(struct igc_adapter *adapter,
 					struct xdp_buff *xdp)
 {
@@ -1947,6 +2049,12 @@ static struct sk_buff *igc_xdp_run_prog(struct igc_adapter *adapter,
 	case XDP_PASS:
 		res = IGC_XDP_PASS;
 		break;
+	case XDP_TX:
+		if (igc_xdp_xmit_back(adapter, xdp) < 0)
+			res = IGC_XDP_CONSUMED;
+		else
+			res = IGC_XDP_TX;
+		break;
 	default:
 		bpf_warn_invalid_xdp_action(act);
 		fallthrough;
@@ -1963,20 +2071,49 @@ static struct sk_buff *igc_xdp_run_prog(struct igc_adapter *adapter,
 	return ERR_PTR(-res);
 }
 
+/* This function assumes __netif_tx_lock is held by the caller. */
+static void igc_flush_tx_descriptors(struct igc_ring *ring)
+{
+	/* Once tail pointer is updated, hardware can fetch the descriptors
+	 * any time so we issue a write membar here to ensure all memory
+	 * writes are complete before the tail pointer is updated.
+	 */
+	wmb();
+	writel(ring->next_to_use, ring->tail);
+}
+
+static void igc_finalize_xdp(struct igc_adapter *adapter, int status)
+{
+	int cpu = smp_processor_id();
+	struct netdev_queue *nq;
+	struct igc_ring *ring;
+
+	if (status & IGC_XDP_TX) {
+		ring = igc_xdp_get_tx_ring(adapter, cpu);
+		nq = txring_txq(ring);
+
+		__netif_tx_lock(nq, cpu);
+		igc_flush_tx_descriptors(ring);
+		__netif_tx_unlock(nq);
+	}
+}
+
 static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
 {
 	unsigned int total_bytes = 0, total_packets = 0;
+	struct igc_adapter *adapter = q_vector->adapter;
 	struct igc_ring *rx_ring = q_vector->rx.ring;
 	struct sk_buff *skb = rx_ring->skb;
 	u16 cleaned_count = igc_desc_unused(rx_ring);
+	int xdp_status = 0;
 
 	while (likely(total_packets < budget)) {
 		union igc_adv_rx_desc *rx_desc;
 		struct igc_rx_buffer *rx_buffer;
+		unsigned int size, truesize;
 		ktime_t timestamp = 0;
 		struct xdp_buff xdp;
 		int pkt_offset = 0;
-		unsigned int size;
 		void *pktbuf;
 
 		/* return some buffers to hardware, one@a time is too slow */
@@ -1997,6 +2134,7 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
 		dma_rmb();
 
 		rx_buffer = igc_get_rx_buffer(rx_ring, size);
+		truesize = igc_get_rx_frame_truesize(rx_ring, size);
 
 		pktbuf = page_address(rx_buffer->page) + rx_buffer->page_offset;
 
@@ -2008,19 +2146,29 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
 		}
 
 		if (!skb) {
-			struct igc_adapter *adapter = q_vector->adapter;
-
 			xdp.data = pktbuf + pkt_offset;
 			xdp.data_end = xdp.data + size;
 			xdp.data_hard_start = pktbuf - igc_rx_offset(rx_ring);
 			xdp_set_data_meta_invalid(&xdp);
-			xdp.frame_sz = igc_get_rx_frame_truesize(rx_ring, size);
+			xdp.frame_sz = truesize;
+			xdp.rxq = &rx_ring->xdp_rxq;
 
 			skb = igc_xdp_run_prog(adapter, &xdp);
 		}
 
 		if (IS_ERR(skb)) {
-			rx_buffer->pagecnt_bias++;
+			unsigned int xdp_res = -PTR_ERR(skb);
+
+			switch (xdp_res) {
+			case IGC_XDP_CONSUMED:
+				rx_buffer->pagecnt_bias++;
+				break;
+			case IGC_XDP_TX:
+				igc_rx_buffer_flip(rx_buffer, truesize);
+				xdp_status |= xdp_res;
+				break;
+			}
+
 			total_packets++;
 			total_bytes += size;
 		} else if (skb)
@@ -2066,6 +2214,9 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
 		total_packets++;
 	}
 
+	if (xdp_status)
+		igc_finalize_xdp(adapter, xdp_status);
+
 	/* place incomplete frames back on ring for completion */
 	rx_ring->skb = skb;
 
@@ -2127,8 +2278,10 @@ static bool igc_clean_tx_irq(struct igc_q_vector *q_vector, int napi_budget)
 		total_bytes += tx_buffer->bytecount;
 		total_packets += tx_buffer->gso_segs;
 
-		/* free the skb */
-		napi_consume_skb(tx_buffer->skb, napi_budget);
+		if (tx_buffer->tx_flags & IGC_TX_FLAGS_XDP)
+			xdp_return_frame(tx_buffer->xdpf);
+		else
+			napi_consume_skb(tx_buffer->skb, napi_budget);
 
 		/* unmap skb header data */
 		dma_unmap_single(tx_ring->dev,
diff --git a/drivers/net/ethernet/intel/igc/igc_xdp.c b/drivers/net/ethernet/intel/igc/igc_xdp.c
index 27c886a254f1..aa65c99c8c4d 100644
--- a/drivers/net/ethernet/intel/igc/igc_xdp.c
+++ b/drivers/net/ethernet/intel/igc/igc_xdp.c
@@ -31,3 +31,30 @@ int igc_xdp_set_prog(struct igc_adapter *adapter, struct bpf_prog *prog,
 
 	return 0;
 }
+
+int igc_xdp_register_rxq_info(struct igc_ring *ring)
+{
+	struct net_device *dev = ring->netdev;
+	int err;
+
+	err = xdp_rxq_info_reg(&ring->xdp_rxq, dev, ring->queue_index);
+	if (err) {
+		netdev_err(dev, "Failed to register xdp rxq info\n");
+		return err;
+	}
+
+	err = xdp_rxq_info_reg_mem_model(&ring->xdp_rxq, MEM_TYPE_PAGE_SHARED,
+					 NULL);
+	if (err) {
+		netdev_err(dev, "Failed to register xdp rxq mem model\n");
+		xdp_rxq_info_unreg(&ring->xdp_rxq);
+		return err;
+	}
+
+	return 0;
+}
+
+void igc_xdp_unregister_rxq_info(struct igc_ring *ring)
+{
+	xdp_rxq_info_unreg(&ring->xdp_rxq);
+}
diff --git a/drivers/net/ethernet/intel/igc/igc_xdp.h b/drivers/net/ethernet/intel/igc/igc_xdp.h
index 8a410bcefe1a..cfecb515b718 100644
--- a/drivers/net/ethernet/intel/igc/igc_xdp.h
+++ b/drivers/net/ethernet/intel/igc/igc_xdp.h
@@ -7,4 +7,7 @@
 int igc_xdp_set_prog(struct igc_adapter *adapter, struct bpf_prog *prog,
 		     struct netlink_ext_ack *extack);
 
+int igc_xdp_register_rxq_info(struct igc_ring *ring);
+void igc_xdp_unregister_rxq_info(struct igc_ring *ring);
+
 #endif /* _IGC_XDP_H_ */
-- 
2.28.0

[Intel-wired-lan] [PATCH v3 9/9] igc: Add support for XDP_REDIRECT action

[Andre Guedes]

This patch adds support for the XDP_REDIRECT action which enables XDP
programs to redirect packets arriving at I225 NIC. It also implements
the ndo_xdp_xmit ops, enabling the igc driver to transmit packets
forwarded to it by xdp programs running on other interfaces.

The patch tweaks the driver's page counting scheme (as described in
'8ce29c679a6e i40e: tweak page counting for XDP_REDIRECT' and
implemented by other Intel drivers) in order to properly support
XDP_REDIRECT action.

This patch has been tested with the sample apps "xdp_redirect_cpu" and
"xdp_redirect_map" located in samples/bpf/.

Signed-off-by: Andre Guedes <andre.guedes@intel.com>
---
 drivers/net/ethernet/intel/igc/igc_main.c | 59 +++++++++++++++++++++--
 1 file changed, 56 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index ae933982e239..33dab5976cbc 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -27,6 +27,7 @@
 #define IGC_XDP_PASS		0
 #define IGC_XDP_CONSUMED	BIT(0)
 #define IGC_XDP_TX		BIT(1)
+#define IGC_XDP_REDIRECT	BIT(2)
 
 static int debug = -1;
 
@@ -1720,8 +1721,8 @@ static bool igc_can_reuse_rx_page(struct igc_rx_buffer *rx_buffer)
 	 * the pagecnt_bias and page count so that we fully restock the
 	 * number of references the driver holds.
 	 */
-	if (unlikely(!pagecnt_bias)) {
-		page_ref_add(page, USHRT_MAX);
+	if (unlikely(pagecnt_bias == 1)) {
+		page_ref_add(page, USHRT_MAX - 1);
 		rx_buffer->pagecnt_bias = USHRT_MAX;
 	}
 
@@ -1862,7 +1863,8 @@ static bool igc_alloc_mapped_page(struct igc_ring *rx_ring,
 	bi->dma = dma;
 	bi->page = page;
 	bi->page_offset = igc_rx_offset(rx_ring);
-	bi->pagecnt_bias = 1;
+	page_ref_add(page, USHRT_MAX - 1);
+	bi->pagecnt_bias = USHRT_MAX;
 
 	return true;
 }
@@ -2055,6 +2057,12 @@ static struct sk_buff *igc_xdp_run_prog(struct igc_adapter *adapter,
 		else
 			res = IGC_XDP_TX;
 		break;
+	case XDP_REDIRECT:
+		if (xdp_do_redirect(adapter->netdev, xdp, prog) < 0)
+			res = IGC_XDP_CONSUMED;
+		else
+			res = IGC_XDP_REDIRECT;
+		break;
 	default:
 		bpf_warn_invalid_xdp_action(act);
 		fallthrough;
@@ -2096,6 +2104,9 @@ static void igc_finalize_xdp(struct igc_adapter *adapter, int status)
 		igc_flush_tx_descriptors(ring);
 		__netif_tx_unlock(nq);
 	}
+
+	if (status & IGC_XDP_REDIRECT)
+		xdp_do_flush();
 }
 
 static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
@@ -2164,6 +2175,7 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
 				rx_buffer->pagecnt_bias++;
 				break;
 			case IGC_XDP_TX:
+			case IGC_XDP_REDIRECT:
 				igc_rx_buffer_flip(rx_buffer, truesize);
 				xdp_status |= xdp_res;
 				break;
@@ -5129,6 +5141,46 @@ static int igc_bpf(struct net_device *dev, struct netdev_bpf *bpf)
 	}
 }
 
+static int igc_xdp_xmit(struct net_device *dev, int num_frames,
+			struct xdp_frame **frames, u32 flags)
+{
+	struct igc_adapter *adapter = netdev_priv(dev);
+	int cpu = smp_processor_id();
+	struct netdev_queue *nq;
+	struct igc_ring *ring;
+	int i, drops;
+
+	if (unlikely(test_bit(__IGC_DOWN, &adapter->state)))
+		return -ENETDOWN;
+
+	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
+		return -EINVAL;
+
+	ring = igc_xdp_get_tx_ring(adapter, cpu);
+	nq = txring_txq(ring);
+
+	__netif_tx_lock(nq, cpu);
+
+	drops = 0;
+	for (i = 0; i < num_frames; i++) {
+		int err;
+		struct xdp_frame *xdpf = frames[i];
+
+		err = igc_xdp_init_tx_descriptor(ring, xdpf);
+		if (err) {
+			xdp_return_frame_rx_napi(xdpf);
+			drops++;
+		}
+	}
+
+	if (flags & XDP_XMIT_FLUSH)
+		igc_flush_tx_descriptors(ring);
+
+	__netif_tx_unlock(nq);
+
+	return num_frames - drops;
+}
+
 static const struct net_device_ops igc_netdev_ops = {
 	.ndo_open		= igc_open,
 	.ndo_stop		= igc_close,
@@ -5143,6 +5195,7 @@ static const struct net_device_ops igc_netdev_ops = {
 	.ndo_do_ioctl		= igc_ioctl,
 	.ndo_setup_tc		= igc_setup_tc,
 	.ndo_bpf		= igc_bpf,
+	.ndo_xdp_xmit		= igc_xdp_xmit,
 };
 
 /* PCIe configuration access */
-- 
2.28.0

[Intel-wired-lan] [PATCH v3 1/9] igc: Fix igc_ptp_rx_pktstamp()

[Maciej Fijalkowski]

On Fri, Oct 30, 2020 at 02:03:43PM -0700, Andre Guedes wrote:
> The comment describing the timestamps layout in the packet buffer is
> wrong and the code is actually retrieving the timestamp in Timer 1
> reference instead of Timer 0. This hasn't been a big issue so far
> because hardware is configured to report both timestamps using Timer 0
> (see IGC_SRRCTL register configuration in igc_ptp_enable_rx_timestamp()
> helper). This patch fixes the comment and the code so we retrieve the
> timestamp in Timer 0 reference as expected.
> 
> This patch also takes the opportunity to get rid of the hw.mac.type check
> since it is not required.
> 
> Fixes: 81b055205e8ba ("igc: Add support for RX timestamping")
> Signed-off-by: Andre Guedes <andre.guedes@intel.com>
> ---
>  drivers/net/ethernet/intel/igc/igc.h     |  2 +-
>  drivers/net/ethernet/intel/igc/igc_ptp.c | 72 +++++++++++++-----------
>  2 files changed, 41 insertions(+), 33 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
> index 83d59b08e883..b66dda992d32 100644
> --- a/drivers/net/ethernet/intel/igc/igc.h
> +++ b/drivers/net/ethernet/intel/igc/igc.h
> @@ -552,7 +552,7 @@ void igc_ptp_init(struct igc_adapter *adapter);
>  void igc_ptp_reset(struct igc_adapter *adapter);
>  void igc_ptp_suspend(struct igc_adapter *adapter);
>  void igc_ptp_stop(struct igc_adapter *adapter);
> -void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, void *va,
> +void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, u32 *va,
>  			 struct sk_buff *skb);
>  int igc_ptp_set_ts_config(struct net_device *netdev, struct ifreq *ifr);
>  int igc_ptp_get_ts_config(struct net_device *netdev, struct ifreq *ifr);
> diff --git a/drivers/net/ethernet/intel/igc/igc_ptp.c b/drivers/net/ethernet/intel/igc/igc_ptp.c
> index d73c4aaac610..79873f6df335 100644
> --- a/drivers/net/ethernet/intel/igc/igc_ptp.c
> +++ b/drivers/net/ethernet/intel/igc/igc_ptp.c
> @@ -154,46 +154,54 @@ static void igc_ptp_systim_to_hwtstamp(struct igc_adapter *adapter,
>  }
>  
>  /**
> - * igc_ptp_rx_pktstamp - retrieve Rx per packet timestamp
> + * igc_ptp_rx_pktstamp - Retrieve timestamp from rx packet buffer
>   * @q_vector: Pointer to interrupt specific structure
>   * @va: Pointer to address containing Rx buffer
>   * @skb: Buffer containing timestamp and packet
>   *
> - * This function is meant to retrieve the first timestamp from the
> - * first buffer of an incoming frame. The value is stored in little
> - * endian format starting on byte 0. There's a second timestamp
> - * starting on byte 8.
> - **/
> -void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, void *va,
> + * This function retrieves the timestamp saved in the beginning of packet
> + * buffer. While two timestamps are available, one in timer0 reference and the
> + * other in timer1 reference, this function considers only the timestamp in
> + * timer0 reference.
> + */
> +void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, u32 *va,
>  			 struct sk_buff *skb)
>  {
>  	struct igc_adapter *adapter = q_vector->adapter;
> -	__le64 *regval = (__le64 *)va;
> -	int adjust = 0;
> -
> -	/* The timestamp is recorded in little endian format.
> -	 * DWORD: | 0          | 1           | 2          | 3
> -	 * Field: | Timer0 Low | Timer0 High | Timer1 Low | Timer1 High
> +	u64 regval;
> +	int adjust;
> +
> +	/* Timestamps are saved in little endian at the beginning of the packet
> +	 * buffer following the layout:
> +	 *
> +	 * | 0              | 1              | 2              | 3              |

Minor nit, I find DWORD comment helpful from previous version of this
description.

> +	 * | Timer1 SYSTIML | Timer1 SYSTIMH | Timer0 SYSTIML | Timer0 SYSTIMH |

A dumb question from ptp/igc noob: why two timers?

> +	 *
> +	 * SYSTIML holds the nanoseconds part while SYSTIMH holds the seconds
> +	 * part of the timestamp.
>  	 */
> -	igc_ptp_systim_to_hwtstamp(adapter, skb_hwtstamps(skb),
> -				   le64_to_cpu(regval[0]));
> -
> -	/* adjust timestamp for the RX latency based on link speed */
> -	if (adapter->hw.mac.type == igc_i225) {

if this check is not required here, then is it within
igc_ptp_systim_to_hwtstamp?

> -		switch (adapter->link_speed) {
> -		case SPEED_10:
> -			adjust = IGC_I225_RX_LATENCY_10;
> -			break;
> -		case SPEED_100:
> -			adjust = IGC_I225_RX_LATENCY_100;
> -			break;
> -		case SPEED_1000:
> -			adjust = IGC_I225_RX_LATENCY_1000;
> -			break;
> -		case SPEED_2500:
> -			adjust = IGC_I225_RX_LATENCY_2500;
> -			break;
> -		}
> +	regval = le32_to_cpu(va[2]);
> +	regval |= (u64)le32_to_cpu(va[3]) << 32;
> +	igc_ptp_systim_to_hwtstamp(adapter, skb_hwtstamps(skb), regval);
> +
> +	/* Adjust timestamp for the RX latency based on link speed */
> +	switch (adapter->link_speed) {
> +	case SPEED_10:
> +		adjust = IGC_I225_RX_LATENCY_10;
> +		break;
> +	case SPEED_100:
> +		adjust = IGC_I225_RX_LATENCY_100;
> +		break;
> +	case SPEED_1000:
> +		adjust = IGC_I225_RX_LATENCY_1000;
> +		break;
> +	case SPEED_2500:
> +		adjust = IGC_I225_RX_LATENCY_2500;
> +		break;
> +	default:
> +		adjust = 0;
> +		netdev_warn_once(adapter->netdev, "Imprecise timestamp\n");

How is timestamp related to link speed? I mean, this warning is telling me
that there is something wrong with the timestamp that hw put onto frame,
not that link speed is cranky.

> +		break;
>  	}
>  	skb_hwtstamps(skb)->hwtstamp =
>  		ktime_sub_ns(skb_hwtstamps(skb)->hwtstamp, adjust);
> -- 
> 2.28.0
> 
> _______________________________________________
> Intel-wired-lan mailing list
> Intel-wired-lan at osuosl.org
> https://lists.osuosl.org/mailman/listinfo/intel-wired-lan

[Intel-wired-lan] [PATCH v3 7/9] igc: Add initial XDP support

[Maciej Fijalkowski]

On Fri, Oct 30, 2020 at 02:03:49PM -0700, Andre Guedes wrote:
> This patch adds the initial XDP support to the igc driver. For now,
> only XDP_PASS, XDP_DROP, XDP_ABORTED actions are supported. Upcoming
> patches will add support for the remaining XDP actions.
> 
> XDP configuration helpers are defined in a new file, igc_xdp.c. These
> helpers are utilized in igc_main.c to implement the ndo_bpf callback.
> XDP-related code that belongs to the driver's hot path is landed in
> igc_main.c.
> 
> By default, the driver uses rx buffers with 2 KB size. When XDP is
> enabled, it uses larger buffers so we have enough space to accommodate
> the headroom and tailroom required by XDP infrastructure. Also, the
> driver doesn't support XDP functionality with frames that span over
> multiple buffers so jumbo frames are not allowed for now.
> 
> The approach implemented by this patch follows the approach implemented
> in other Intel drivers as much as possible for the sake of consistency
> across the drivers.
> 
> Quick comment regarding igc_build_skb(): this patch doesn't touch it
> because the function is never called. It seems its support is
> incomplete/in progress. The function was added by commit 0507ef8a0372b
> ("igc: Add transmit and receive fastpath and interrupt handlers") but
> ring_uses_build_skb() always return False since the IGC_RING_FLAG_RX_
> BUILD_SKB_ENABLED isn't set anywhere in the driver code.
> 
> This patch has been tested with the sample app "xdp1" located in
> samples/bpf/ dir.
> 
> Signed-off-by: Andre Guedes <andre.guedes@intel.com>
> ---
>  drivers/net/ethernet/intel/igc/Makefile   |   2 +-
>  drivers/net/ethernet/intel/igc/igc.h      |   2 +
>  drivers/net/ethernet/intel/igc/igc_main.c | 118 ++++++++++++++++++++--
>  drivers/net/ethernet/intel/igc/igc_xdp.c  |  33 ++++++
>  drivers/net/ethernet/intel/igc/igc_xdp.h  |  10 ++
>  5 files changed, 153 insertions(+), 12 deletions(-)
>  create mode 100644 drivers/net/ethernet/intel/igc/igc_xdp.c
>  create mode 100644 drivers/net/ethernet/intel/igc/igc_xdp.h
> 
> diff --git a/drivers/net/ethernet/intel/igc/Makefile b/drivers/net/ethernet/intel/igc/Makefile
> index 1c3051db9085..95d1e8c490a4 100644
> --- a/drivers/net/ethernet/intel/igc/Makefile
> +++ b/drivers/net/ethernet/intel/igc/Makefile
> @@ -8,4 +8,4 @@
>  obj-$(CONFIG_IGC) += igc.o
>  
>  igc-objs := igc_main.o igc_mac.o igc_i225.o igc_base.o igc_nvm.o igc_phy.o \
> -igc_diag.o igc_ethtool.o igc_ptp.o igc_dump.o igc_tsn.o
> +igc_diag.o igc_ethtool.o igc_ptp.o igc_dump.o igc_tsn.o igc_xdp.o
> diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
> index e72f1fc772aa..5c2f363106ae 100644
> --- a/drivers/net/ethernet/intel/igc/igc.h
> +++ b/drivers/net/ethernet/intel/igc/igc.h
> @@ -224,6 +224,8 @@ struct igc_adapter {
>  	struct mutex ptm_time_lock; /* protects host and device timestamps */
>  	ktime_t ptm_device_time;
>  	struct system_counterval_t ptm_host_time;
> +
> +	struct bpf_prog *xdp_prog;
>  };
>  
>  void igc_up(struct igc_adapter *adapter);
> diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
> index 84ffde75e968..734a570bbadb 100644
> --- a/drivers/net/ethernet/intel/igc/igc_main.c
> +++ b/drivers/net/ethernet/intel/igc/igc_main.c
> @@ -11,17 +11,22 @@
>  #include <linux/pm_runtime.h>
>  #include <net/pkt_sched.h>
>  #include <linux/pci.h>
> +#include <linux/bpf_trace.h>
>  
>  #include <net/ipv6.h>
>  
>  #include "igc.h"
>  #include "igc_hw.h"
>  #include "igc_tsn.h"
> +#include "igc_xdp.h"
>  
>  #define DRV_SUMMARY	"Intel(R) 2.5G Ethernet Linux Driver"
>  
>  #define DEFAULT_MSG_ENABLE (NETIF_MSG_DRV | NETIF_MSG_PROBE | NETIF_MSG_LINK)
>  
> +#define IGC_XDP_PASS		0
> +#define IGC_XDP_CONSUMED	BIT(0)
> +
>  static int debug = -1;
>  
>  MODULE_AUTHOR("Intel Corporation, <linux.nics@intel.com>");
> @@ -346,6 +351,8 @@ static void igc_clean_rx_ring(struct igc_ring *rx_ring)
>  {
>  	u16 i = rx_ring->next_to_clean;
>  
> +	clear_ring_uses_large_buffer(rx_ring);
> +
>  	dev_kfree_skb(rx_ring->skb);
>  	rx_ring->skb = NULL;
>  
> @@ -498,6 +505,11 @@ static int igc_setup_all_rx_resources(struct igc_adapter *adapter)
>  	return err;
>  }
>  
> +static bool igc_xdp_is_enabled(struct igc_adapter *adapter)
> +{
> +	return !!adapter->xdp_prog;
> +}
> +
>  /**
>   * igc_configure_rx_ring - Configure a receive ring after Reset
>   * @adapter: board private structure
> @@ -514,6 +526,9 @@ static void igc_configure_rx_ring(struct igc_adapter *adapter,
>  	u32 srrctl = 0, rxdctl = 0;
>  	u64 rdba = ring->dma;
>  
> +	if (igc_xdp_is_enabled(adapter))
> +		set_ring_uses_large_buffer(ring);
> +
>  	/* disable the queue */
>  	wr32(IGC_RXDCTL(reg_idx), 0);
>  
> @@ -1594,12 +1609,12 @@ static struct sk_buff *igc_build_skb(struct igc_ring *rx_ring,
>  
>  static struct sk_buff *igc_construct_skb(struct igc_ring *rx_ring,
>  					 struct igc_rx_buffer *rx_buffer,
> -					 unsigned int size, int pkt_offset,
> +					 struct xdp_buff *xdp,
>  					 ktime_t timestamp)
>  {
> -	void *va = page_address(rx_buffer->page) + rx_buffer->page_offset +
> -		   pkt_offset;
> +	unsigned int size = xdp->data_end - xdp->data;
>  	unsigned int truesize = igc_get_rx_frame_truesize(rx_ring, size);
> +	void *va = xdp->data;
>  	unsigned int headlen;
>  	struct sk_buff *skb;
>  
> @@ -1748,6 +1763,10 @@ static bool igc_cleanup_headers(struct igc_ring *rx_ring,
>  				union igc_adv_rx_desc *rx_desc,
>  				struct sk_buff *skb)
>  {
> +	/* XDP packets use error pointer so abort at this point */
> +	if (IS_ERR(skb))
> +		return true;
> +
>  	if (unlikely(igc_test_staterr(rx_desc, IGC_RXDEXT_STATERR_RXE))) {
>  		struct net_device *netdev = rx_ring->netdev;
>  
> @@ -1787,7 +1806,14 @@ static void igc_put_rx_buffer(struct igc_ring *rx_ring,
>  
>  static inline unsigned int igc_rx_offset(struct igc_ring *rx_ring)
>  {
> -	return ring_uses_build_skb(rx_ring) ? IGC_SKB_PAD : 0;
> +	struct igc_adapter *adapter = rx_ring->q_vector->adapter;
> +
> +	if (ring_uses_build_skb(rx_ring))
> +		return IGC_SKB_PAD;
> +	if (igc_xdp_is_enabled(adapter))
> +		return XDP_PACKET_HEADROOM;
> +
> +	return 0;
>  }
>  
>  static bool igc_alloc_mapped_page(struct igc_ring *rx_ring,
> @@ -1901,6 +1927,42 @@ static void igc_alloc_rx_buffers(struct igc_ring *rx_ring, u16 cleaned_count)
>  	}
>  }
>  
> +static struct sk_buff *igc_xdp_run_prog(struct igc_adapter *adapter,
> +					struct xdp_buff *xdp)
> +{
> +	struct bpf_prog *prog;
> +	int res;
> +	u32 act;
> +
> +	rcu_read_lock();
> +
> +	prog = READ_ONCE(adapter->xdp_prog);
> +	if (!prog) {
> +		res = IGC_XDP_PASS;
> +		goto unlock;
> +	}
> +
> +	act = bpf_prog_run_xdp(prog, xdp);
> +	switch (act) {
> +	case XDP_PASS:
> +		res = IGC_XDP_PASS;
> +		break;
> +	default:
> +		bpf_warn_invalid_xdp_action(act);
> +		fallthrough;
> +	case XDP_ABORTED:
> +		trace_xdp_exception(adapter->netdev, prog, act);
> +		fallthrough;
> +	case XDP_DROP:
> +		res = IGC_XDP_CONSUMED;
> +		break;
> +	}
> +
> +unlock:
> +	rcu_read_unlock();
> +	return ERR_PTR(-res);
> +}
> +
>  static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
>  {
>  	unsigned int total_bytes = 0, total_packets = 0;
> @@ -1912,8 +1974,10 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
>  		union igc_adv_rx_desc *rx_desc;
>  		struct igc_rx_buffer *rx_buffer;
>  		ktime_t timestamp = 0;
> +		struct xdp_buff xdp;

I'm wondering if this patch should zero-init the xdp_buff. There are two
pointers that are left untouched below (rxq/txq) so maybe bpf prog would
get some weird behavior if it would be touching them.

>  		int pkt_offset = 0;
>  		unsigned int size;
> +		void *pktbuf;
>  
>  		/* return some buffers to hardware, one at a time is too slow */
>  		if (cleaned_count >= IGC_RX_BUFFER_WRITE) {
> @@ -1934,24 +1998,38 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
>  
>  		rx_buffer = igc_get_rx_buffer(rx_ring, size);
>  
> -		if (igc_test_staterr(rx_desc, IGC_RXDADV_STAT_TSIP)) {
> -			void *pktbuf = page_address(rx_buffer->page) +
> -				       rx_buffer->page_offset;
> +		pktbuf = page_address(rx_buffer->page) + rx_buffer->page_offset;
>  
> +		if (igc_test_staterr(rx_desc, IGC_RXDADV_STAT_TSIP)) {
>  			timestamp = igc_ptp_rx_pktstamp(q_vector->adapter,
>  							pktbuf);
>  			pkt_offset = IGC_TS_HDR_LEN;
>  			size -= IGC_TS_HDR_LEN;
>  		}
>  
> -		/* retrieve a buffer from the ring */
> -		if (skb)
> +		if (!skb) {
> +			struct igc_adapter *adapter = q_vector->adapter;
> +
> +			xdp.data = pktbuf + pkt_offset;
> +			xdp.data_end = xdp.data + size;
> +			xdp.data_hard_start = pktbuf - igc_rx_offset(rx_ring);
> +			xdp_set_data_meta_invalid(&xdp);
> +			xdp.frame_sz = igc_get_rx_frame_truesize(rx_ring, size);
> +
> +			skb = igc_xdp_run_prog(adapter, &xdp);
> +		}
> +
> +		if (IS_ERR(skb)) {
> +			rx_buffer->pagecnt_bias++;
> +			total_packets++;
> +			total_bytes += size;
> +		} else if (skb)
>  			igc_add_rx_frag(rx_ring, rx_buffer, skb, size);
>  		else if (ring_uses_build_skb(rx_ring))
>  			skb = igc_build_skb(rx_ring, rx_buffer, rx_desc, size);
>  		else
> -			skb = igc_construct_skb(rx_ring, rx_buffer, size,
> -						pkt_offset, timestamp);
> +			skb = igc_construct_skb(rx_ring, rx_buffer, &xdp,
> +						timestamp);
>  
>  		/* exit if we failed to retrieve a buffer */
>  		if (!skb) {
> @@ -3893,6 +3971,11 @@ static int igc_change_mtu(struct net_device *netdev, int new_mtu)
>  	int max_frame = new_mtu + ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN;
>  	struct igc_adapter *adapter = netdev_priv(netdev);
>  
> +	if (igc_xdp_is_enabled(adapter) && new_mtu > ETH_DATA_LEN) {
> +		netdev_dbg(netdev, "Jumbo frames not supported with XDP");
> +		return -EINVAL;
> +	}
> +
>  	/* adjust max frame to be at least the size of a standard frame */
>  	if (max_frame < (ETH_FRAME_LEN + ETH_FCS_LEN))
>  		max_frame = ETH_FRAME_LEN + ETH_FCS_LEN;
> @@ -4881,6 +4964,18 @@ static int igc_setup_tc(struct net_device *dev, enum tc_setup_type type,
>  	}
>  }
>  
> +static int igc_bpf(struct net_device *dev, struct netdev_bpf *bpf)
> +{
> +	struct igc_adapter *adapter = netdev_priv(dev);
> +
> +	switch (bpf->command) {
> +	case XDP_SETUP_PROG:
> +		return igc_xdp_set_prog(adapter, bpf->prog, bpf->extack);
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +}
> +
>  static const struct net_device_ops igc_netdev_ops = {
>  	.ndo_open		= igc_open,
>  	.ndo_stop		= igc_close,
> @@ -4894,6 +4989,7 @@ static const struct net_device_ops igc_netdev_ops = {
>  	.ndo_features_check	= igc_features_check,
>  	.ndo_do_ioctl		= igc_ioctl,
>  	.ndo_setup_tc		= igc_setup_tc,
> +	.ndo_bpf		= igc_bpf,
>  };
>  
>  /* PCIe configuration access */
> diff --git a/drivers/net/ethernet/intel/igc/igc_xdp.c b/drivers/net/ethernet/intel/igc/igc_xdp.c
> new file mode 100644
> index 000000000000..27c886a254f1
> --- /dev/null
> +++ b/drivers/net/ethernet/intel/igc/igc_xdp.c
> @@ -0,0 +1,33 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (c) 2020, Intel Corporation. */
> +
> +#include "igc.h"
> +#include "igc_xdp.h"
> +
> +int igc_xdp_set_prog(struct igc_adapter *adapter, struct bpf_prog *prog,
> +		     struct netlink_ext_ack *extack)
> +{
> +	struct net_device *dev = adapter->netdev;
> +	bool if_running = netif_running(dev);
> +	struct bpf_prog *old_prog;
> +
> +	if (dev->mtu > ETH_DATA_LEN) {
> +		/* For now, the driver doesn't support XDP functionality with
> +		 * jumbo frames so we return error.
> +		 */
> +		NL_SET_ERR_MSG_MOD(extack, "Jumbo frames not supported");
> +		return -EOPNOTSUPP;
> +	}
> +
> +	if (if_running)
> +		igc_close(dev);
> +
> +	old_prog = xchg(&adapter->xdp_prog, prog);
> +	if (old_prog)
> +		bpf_prog_put(old_prog);
> +
> +	if (if_running)
> +		igc_open(dev);
> +
> +	return 0;
> +}
> diff --git a/drivers/net/ethernet/intel/igc/igc_xdp.h b/drivers/net/ethernet/intel/igc/igc_xdp.h
> new file mode 100644
> index 000000000000..8a410bcefe1a
> --- /dev/null
> +++ b/drivers/net/ethernet/intel/igc/igc_xdp.h
> @@ -0,0 +1,10 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/* Copyright (c) 2020, Intel Corporation. */
> +
> +#ifndef _IGC_XDP_H_
> +#define _IGC_XDP_H_
> +
> +int igc_xdp_set_prog(struct igc_adapter *adapter, struct bpf_prog *prog,
> +		     struct netlink_ext_ack *extack);
> +
> +#endif /* _IGC_XDP_H_ */
> -- 
> 2.28.0
> 
> _______________________________________________
> Intel-wired-lan mailing list
> Intel-wired-lan at osuosl.org
> https://lists.osuosl.org/mailman/listinfo/intel-wired-lan

[Intel-wired-lan] [PATCH v3 8/9] igc: Add support for XDP_TX action

[Maciej Fijalkowski]

On Fri, Oct 30, 2020 at 02:03:50PM -0700, Andre Guedes wrote:
> This patch adds support for XDP_TX action which enables XDP programs to
> transmit back receiving frames.
> 
> I225 controller has only 4 tx hardware queues. Since XDP programs may
> not even issue an XDP_TX action, this patch doesn't reserve dedicated
> queues just for XDP like other Intel drivers do. Instead, the queues
> are shared between the network stack and XDP. The netdev queue lock is
> used to ensure mutual exclusion.
> 
> Since frames can now be transmitted via XDP_TX, the igc_tx_buffer
> structure is modified so we are able to save a reference to the xdp
> frame for later clean up once the packet is transmitted. The tx_buffer
> is mapped to either a skb or a xdpf so we use a union to save the skb
> or xdpf pointer and have a bit in tx_flags to indicate which field to
> use.
> 
> This patch has been tested with the sample app "xdp2" located in
> samples/bpf/ dir.
> 
> Signed-off-by: Andre Guedes <andre.guedes@intel.com>
> ---

[...]

> +
> +static struct igc_ring *igc_xdp_get_tx_ring(struct igc_adapter *adapter,
> +					    int cpu)
> +{
> +	int index = cpu;
> +
> +	if (index >= adapter->num_tx_queues)
> +		index = index % adapter->num_tx_queues;

I'm not sure why you don't want to take the suggestion for getting rid of
modulo op. I won't insist anymore ;)

> +
> +	return adapter->tx_ring[index];
> +}

[...]

[Intel-wired-lan] [PATCH v3 9/9] igc: Add support for XDP_REDIRECT action

[Maciej Fijalkowski]

On Fri, Oct 30, 2020 at 02:03:51PM -0700, Andre Guedes wrote:
> This patch adds support for the XDP_REDIRECT action which enables XDP
> programs to redirect packets arriving at I225 NIC. It also implements
> the ndo_xdp_xmit ops, enabling the igc driver to transmit packets
> forwarded to it by xdp programs running on other interfaces.
> 
> The patch tweaks the driver's page counting scheme (as described in
> '8ce29c679a6e i40e: tweak page counting for XDP_REDIRECT' and
> implemented by other Intel drivers) in order to properly support
> XDP_REDIRECT action.
> 
> This patch has been tested with the sample apps "xdp_redirect_cpu" and
> "xdp_redirect_map" located in samples/bpf/.

Did you test in a way that the igc interface was the second interface for
redirect samples and you checked that tx happened?

> 
> Signed-off-by: Andre Guedes <andre.guedes@intel.com>
> ---

[Intel-wired-lan] [PATCH v3 0/9] igc: Add XDP support

[Maciej Fijalkowski]

On Fri, Oct 30, 2020 at 02:03:42PM -0700, Andre Guedes wrote:
> Hi all,
> 
> This is the third version of this series which adds XDP support to igc driver.
> 
> The main changes from v2 are:
> 
>     - Moved functions that belong to the driver's hot path to igc_main.c to
>       allow the compiler to inline them if convenient.
>     - Squashed ndo_xdp_xmit patch into XDP_REDIRECT patch.
> 
> v2 is here:
> 
>     https://patchwork.ozlabs.org/project/intel-wired-lan/cover/20201028201943.93147-1-andre.guedes at intel.com/
> 
> v1 is here:
> 
>     https://patchwork.ozlabs.org/project/intel-wired-lan/cover/20201009025349.4037-1-andre.guedes at intel.com/
> 
> Cheers,
> Andre

I had only minor comments/questions for this version, so you can take my:

Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>

for series.

> 
> 
> Andre Guedes (9):
>   igc: Fix igc_ptp_rx_pktstamp()
>   igc: Remove unused argument from igc_tx_cmd_type()
>   igc: Introduce igc_rx_buffer_flip() helper
>   igc: Introduce igc_get_rx_frame_truesize() helper
>   igc: Refactor rx timestamp handling
>   igc: Add set/clear large buffer helpers
>   igc: Add initial XDP support
>   igc: Add support for XDP_TX action
>   igc: Add support for XDP_REDIRECT action
> 
>  drivers/net/ethernet/intel/igc/Makefile   |   2 +-
>  drivers/net/ethernet/intel/igc/igc.h      |  18 +-
>  drivers/net/ethernet/intel/igc/igc_main.c | 431 +++++++++++++++++++---
>  drivers/net/ethernet/intel/igc/igc_ptp.c  |  89 +++--
>  drivers/net/ethernet/intel/igc/igc_xdp.c  |  60 +++
>  drivers/net/ethernet/intel/igc/igc_xdp.h  |  13 +
>  6 files changed, 512 insertions(+), 101 deletions(-)
>  create mode 100644 drivers/net/ethernet/intel/igc/igc_xdp.c
>  create mode 100644 drivers/net/ethernet/intel/igc/igc_xdp.h
> 
> -- 
> 2.28.0
> 
> _______________________________________________
> Intel-wired-lan mailing list
> Intel-wired-lan at osuosl.org
> https://lists.osuosl.org/mailman/listinfo/intel-wired-lan

[Intel-wired-lan] [PATCH v3 1/9] igc: Fix igc_ptp_rx_pktstamp()

[Andre Guedes]

Quoting Maciej Fijalkowski (2020-11-02 09:56:17)
> > +void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, u32 *va,
> >                        struct sk_buff *skb)
> >  {
> >       struct igc_adapter *adapter = q_vector->adapter;
> > -     __le64 *regval = (__le64 *)va;
> > -     int adjust = 0;
> > -
> > -     /* The timestamp is recorded in little endian format.
> > -      * DWORD: | 0          | 1           | 2          | 3
> > -      * Field: | Timer0 Low | Timer0 High | Timer1 Low | Timer1 High
> > +     u64 regval;
> > +     int adjust;
> > +
> > +     /* Timestamps are saved in little endian at the beginning of the packet
> > +      * buffer following the layout:
> > +      *
> > +      * | 0              | 1              | 2              | 3              |
> 
> Minor nit, I find DWORD comment helpful from previous version of this
> description.

Let me bring that comment back.

> 
> > +      * | Timer1 SYSTIML | Timer1 SYSTIMH | Timer0 SYSTIML | Timer0 SYSTIMH |
> 
> A dumb question from ptp/igc noob: why two timers?

i225 has 4 independent timers and software can select 2 of them to be sampled
when the packet is received. One use case I can think of is to help with
cross-timestamping in multiple clocks scenario so you could have a "global"
timestamp and a "local" timestamp for a single packet.

> > +      *
> > +      * SYSTIML holds the nanoseconds part while SYSTIMH holds the seconds
> > +      * part of the timestamp.
> >        */
> > -     igc_ptp_systim_to_hwtstamp(adapter, skb_hwtstamps(skb),
> > -                                le64_to_cpu(regval[0]));
> > -
> > -     /* adjust timestamp for the RX latency based on link speed */
> > -     if (adapter->hw.mac.type == igc_i225) {
> 
> if this check is not required here, then is it within
> igc_ptp_systim_to_hwtstamp?

It is not required in igc_ptp_systim_to_hwtstamp() either. As discussed in [1]
these checks will be cleaned up in a separate series.

> > +     /* Adjust timestamp for the RX latency based on link speed */
> > +     switch (adapter->link_speed) {
> > +     case SPEED_10:
> > +             adjust = IGC_I225_RX_LATENCY_10;
> > +             break;
> > +     case SPEED_100:
> > +             adjust = IGC_I225_RX_LATENCY_100;
> > +             break;
> > +     case SPEED_1000:
> > +             adjust = IGC_I225_RX_LATENCY_1000;
> > +             break;
> > +     case SPEED_2500:
> > +             adjust = IGC_I225_RX_LATENCY_2500;
> > +             break;
> > +     default:
> > +             adjust = 0;
> > +             netdev_warn_once(adapter->netdev, "Imprecise timestamp\n");
> 
> How is timestamp related to link speed? I mean, this warning is telling me
> that there is something wrong with the timestamp that hw put onto frame,
> not that link speed is cranky.

The timestamp is sampled at the beginning of the packet. Although the timestamp
logic is located as close as possible to the PHY interface, there is a latency
between the moment the PHY received the first bit of the packet and the moment
the timestamp logic samples. That latency depends on the link speed and is
specified in the datasheet so software can adjust it.

In this regards, i225 is similar to i210 so you can take a look at section
7.8.3.1 Capture Timestamp Mechanism from i210 datasheet for further details.

Best,
Andre

[1] https://patchwork.ozlabs.org/project/intel-wired-lan/patch/20200519101644.8246-1-sasha.neftin at intel.com/

[Intel-wired-lan] [PATCH v3 7/9] igc: Add initial XDP support

[Andre Guedes]

Quoting Maciej Fijalkowski (2020-11-02 10:07:00)
> >  static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
> >  {
> >       unsigned int total_bytes = 0, total_packets = 0;
> > @@ -1912,8 +1974,10 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
> >               union igc_adv_rx_desc *rx_desc;
> >               struct igc_rx_buffer *rx_buffer;
> >               ktime_t timestamp = 0;
> > +             struct xdp_buff xdp;
> 
> I'm wondering if this patch should zero-init the xdp_buff. There are two
> pointers that are left untouched below (rxq/txq) so maybe bpf prog would
> get some weird behavior if it would be touching them.

I see your point. While rxq is set by the next patch txq is not. I took a look
at ice, i40e, ixgbe, and they don't seem to zero-init neither set txq so maybe
that's OK.

[Intel-wired-lan] [PATCH v3 8/9] igc: Add support for XDP_TX action

[Andre Guedes]

Quoting Maciej Fijalkowski (2020-11-02 10:26:59)
> > +static struct igc_ring *igc_xdp_get_tx_ring(struct igc_adapter *adapter,
> > +                                         int cpu)
> > +{
> > +     int index = cpu;
> > +
> > +     if (index >= adapter->num_tx_queues)
> > +             index = index % adapter->num_tx_queues;
> 
> I'm not sure why you don't want to take the suggestion for getting rid of
> modulo op. I won't insist anymore ;)

As I mentioned in the previous comment, I was just following the same
approach from igb. Since I'll submit a v4 already, I'll do that as well.

[Intel-wired-lan] [PATCH v3 9/9] igc: Add support for XDP_REDIRECT action

[Andre Guedes]

Quoting Maciej Fijalkowski (2020-11-02 10:30:07)
> On Fri, Oct 30, 2020 at 02:03:51PM -0700, Andre Guedes wrote:
> > This patch adds support for the XDP_REDIRECT action which enables XDP
> > programs to redirect packets arriving at I225 NIC. It also implements
> > the ndo_xdp_xmit ops, enabling the igc driver to transmit packets
> > forwarded to it by xdp programs running on other interfaces.
> > 
> > The patch tweaks the driver's page counting scheme (as described in
> > '8ce29c679a6e i40e: tweak page counting for XDP_REDIRECT' and
> > implemented by other Intel drivers) in order to properly support
> > XDP_REDIRECT action.
> > 
> > This patch has been tested with the sample apps "xdp_redirect_cpu" and
> > "xdp_redirect_map" located in samples/bpf/.
> 
> Did you test in a way that the igc interface was the second interface for
> redirect samples and you checked that tx happened?

I tested both ways with xdp_redirect_map i.e. igc interface as the IFNAME_IN
and as the IFNAME_OUT arguments.

[Intel-wired-lan] [PATCH v3 0/9] igc: Add XDP support

[Andre Guedes]

Quoting Maciej Fijalkowski (2020-11-02 10:31:29)
> On Fri, Oct 30, 2020 at 02:03:42PM -0700, Andre Guedes wrote:
> > Hi all,
> > 
> > This is the third version of this series which adds XDP support to igc driver.
> > 
> > The main changes from v2 are:
> > 
> >     - Moved functions that belong to the driver's hot path to igc_main.c to
> >       allow the compiler to inline them if convenient.
> >     - Squashed ndo_xdp_xmit patch into XDP_REDIRECT patch.
> > 
> > v2 is here:
> > 
> >     https://patchwork.ozlabs.org/project/intel-wired-lan/cover/20201028201943.93147-1-andre.guedes at intel.com/
> > 
> > v1 is here:
> > 
> >     https://patchwork.ozlabs.org/project/intel-wired-lan/cover/20201009025349.4037-1-andre.guedes at intel.com/
> > 
> > Cheers,
> > Andre
> 
> I had only minor comments/questions for this version, so you can take my:
> 
> Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
> 
> for series.

Thanks for the review, Maceij! I'm adding your Reviewed-by to the next version
of this series I'm submitting soon.

[Intel-wired-lan] [PATCH v3 7/9] igc: Add initial XDP support

[Maciej Fijalkowski]

On Tue, Nov 03, 2020 at 03:40:21PM -0800, Andre Guedes wrote:
> Quoting Maciej Fijalkowski (2020-11-02 10:07:00)
> > >  static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
> > >  {
> > >       unsigned int total_bytes = 0, total_packets = 0;
> > > @@ -1912,8 +1974,10 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_vector, const int budget)
> > >               union igc_adv_rx_desc *rx_desc;
> > >               struct igc_rx_buffer *rx_buffer;
> > >               ktime_t timestamp = 0;
> > > +             struct xdp_buff xdp;
> > 
> > I'm wondering if this patch should zero-init the xdp_buff. There are two
> > pointers that are left untouched below (rxq/txq) so maybe bpf prog would
> > get some weird behavior if it would be touching them.
> 
> I see your point. While rxq is set by the next patch txq is not. I took a look
> at ice, i40e, ixgbe, and they don't seem to zero-init neither set txq so maybe
> that's OK.

To clear it up, txq in xdp_buff is explicitly set in dev_map_run_prog(),
which is sort of a xdp tx hook. That's why none of the driver has to do
that. Sorry for confusion :)

[Intel-wired-lan] [PATCH v3 1/9] igc: Fix igc_ptp_rx_pktstamp()

[Maciej Fijalkowski]

On Tue, Nov 03, 2020 at 03:39:58PM -0800, Andre Guedes wrote:
> Quoting Maciej Fijalkowski (2020-11-02 09:56:17)
> > > +void igc_ptp_rx_pktstamp(struct igc_q_vector *q_vector, u32 *va,
> > >                        struct sk_buff *skb)
> > >  {
> > >       struct igc_adapter *adapter = q_vector->adapter;
> > > -     __le64 *regval = (__le64 *)va;
> > > -     int adjust = 0;
> > > -
> > > -     /* The timestamp is recorded in little endian format.
> > > -      * DWORD: | 0          | 1           | 2          | 3
> > > -      * Field: | Timer0 Low | Timer0 High | Timer1 Low | Timer1 High
> > > +     u64 regval;
> > > +     int adjust;
> > > +
> > > +     /* Timestamps are saved in little endian at the beginning of the packet
> > > +      * buffer following the layout:
> > > +      *
> > > +      * | 0              | 1              | 2              | 3              |
> > 
> > Minor nit, I find DWORD comment helpful from previous version of this
> > description.
> 
> Let me bring that comment back.
> 
> > 
> > > +      * | Timer1 SYSTIML | Timer1 SYSTIMH | Timer0 SYSTIML | Timer0 SYSTIMH |
> > 
> > A dumb question from ptp/igc noob: why two timers?
> 
> i225 has 4 independent timers and software can select 2 of them to be sampled
> when the packet is received. One use case I can think of is to help with
> cross-timestamping in multiple clocks scenario so you could have a "global"
> timestamp and a "local" timestamp for a single packet.
> 
> > > +      *
> > > +      * SYSTIML holds the nanoseconds part while SYSTIMH holds the seconds
> > > +      * part of the timestamp.
> > >        */
> > > -     igc_ptp_systim_to_hwtstamp(adapter, skb_hwtstamps(skb),
> > > -                                le64_to_cpu(regval[0]));
> > > -
> > > -     /* adjust timestamp for the RX latency based on link speed */
> > > -     if (adapter->hw.mac.type == igc_i225) {
> > 
> > if this check is not required here, then is it within
> > igc_ptp_systim_to_hwtstamp?
> 
> It is not required in igc_ptp_systim_to_hwtstamp() either. As discussed in [1]
> these checks will be cleaned up in a separate series.

Okay thanks.

> 
> > > +     /* Adjust timestamp for the RX latency based on link speed */
> > > +     switch (adapter->link_speed) {
> > > +     case SPEED_10:
> > > +             adjust = IGC_I225_RX_LATENCY_10;
> > > +             break;
> > > +     case SPEED_100:
> > > +             adjust = IGC_I225_RX_LATENCY_100;
> > > +             break;
> > > +     case SPEED_1000:
> > > +             adjust = IGC_I225_RX_LATENCY_1000;
> > > +             break;
> > > +     case SPEED_2500:
> > > +             adjust = IGC_I225_RX_LATENCY_2500;
> > > +             break;
> > > +     default:
> > > +             adjust = 0;
> > > +             netdev_warn_once(adapter->netdev, "Imprecise timestamp\n");
> > 
> > How is timestamp related to link speed? I mean, this warning is telling me
> > that there is something wrong with the timestamp that hw put onto frame,
> > not that link speed is cranky.
> 
> The timestamp is sampled at the beginning of the packet. Although the timestamp
> logic is located as close as possible to the PHY interface, there is a latency
> between the moment the PHY received the first bit of the packet and the moment
> the timestamp logic samples. That latency depends on the link speed and is
> specified in the datasheet so software can adjust it.

Thanks for that explanation! I meant that warning should say something
like "wrong link speed, can not adjust timestamp", but OTOH I have a
feeling that all of the speeds that this HW supports are handled in this
switch statement, so probably arguing about that warning is pointless? :)

> 
> In this regards, i225 is similar to i210 so you can take a look at section
> 7.8.3.1 Capture Timestamp Mechanism from i210 datasheet for further details.
> 
> Best,
> Andre
> 
> [1] https://patchwork.ozlabs.org/project/intel-wired-lan/patch/20200519101644.8246-1-sasha.neftin at intel.com/

[Intel-wired-lan] [PATCH v3 8/9] igc: Add support for XDP_TX action

[Vinicius Costa Gomes]

Hi,

Andre Guedes <andre.guedes@intel.com> writes:

> Quoting Maciej Fijalkowski (2020-11-02 10:26:59)
>> > +static struct igc_ring *igc_xdp_get_tx_ring(struct igc_adapter *adapter,
>> > +                                         int cpu)
>> > +{
>> > +     int index = cpu;
>> > +
>> > +     if (index >= adapter->num_tx_queues)
>> > +             index = index % adapter->num_tx_queues;
>> 
>> I'm not sure why you don't want to take the suggestion for getting rid of
>> modulo op. I won't insist anymore ;)
>
> As I mentioned in the previous comment, I was just following the same
> approach from igb. Since I'll submit a v4 already, I'll do that as
> well.

Another idea is to use iter_div_u64_rem() as the expected difference
between divident and divisor should be small.


Cheers,
-- 
Vinicius

[Intel-wired-lan] [PATCH v3 1/9] igc: Fix igc_ptp_rx_pktstamp()

[Guedes, Andre]

> On Nov 4, 2020, at 2:26 PM, Fijalkowski, Maciej <maciej.fijalkowski@intel.com> wrote:
> 
>>>> 
>>>> +     /* Adjust timestamp for the RX latency based on link speed */
>>>> +     switch (adapter->link_speed) {
>>>> +     case SPEED_10:
>>>> +             adjust = IGC_I225_RX_LATENCY_10;
>>>> +             break;
>>>> +     case SPEED_100:
>>>> +             adjust = IGC_I225_RX_LATENCY_100;
>>>> +             break;
>>>> +     case SPEED_1000:
>>>> +             adjust = IGC_I225_RX_LATENCY_1000;
>>>> +             break;
>>>> +     case SPEED_2500:
>>>> +             adjust = IGC_I225_RX_LATENCY_2500;
>>>> +             break;
>>>> +     default:
>>>> +             adjust = 0;
>>>> +             netdev_warn_once(adapter->netdev, "Imprecise timestamp\n");
>>> 
>>> How is timestamp related to link speed? I mean, this warning is telling me
>>> that there is something wrong with the timestamp that hw put onto frame,
>>> not that link speed is cranky.
>> 
>> The timestamp is sampled at the beginning of the packet. Although the timestamp
>> logic is located as close as possible to the PHY interface, there is a latency
>> between the moment the PHY received the first bit of the packet and the moment
>> the timestamp logic samples. That latency depends on the link speed and is
>> specified in the datasheet so software can adjust it.
> 
> Thanks for that explanation! I meant that warning should say something
> like "wrong link speed, can not adjust timestamp", but OTOH I have a
> feeling that all of the speeds that this HW supports are handled in this
> switch statement, so probably arguing about that warning is pointless? :)

For TSN use cases, timestamp precision is very important. If, for any reason, adapter->link_speed is off, we want to at least log that information.