[Patch v1 net-next 00/10] Use build_skb and reorganize some code in ENA

[Patch v1 net-next 00/10] Use build_skb and reorganize some code in ENA

[Shay Agroskin]

Hi all,
this patchset introduces several changes:

- Use build_skb() on RX side.
  This allows to ensure that the headers are in the linear part

- Batch some code into functions and remove some of the code to make it more
  readable and less error prone

- Fix RST format and outdated description in ENA documentation

- Improve cache alignment in the code

Please review

Shay Agroskin (10):
  net: ena: optimize data access in fast-path code
  net: ena: Remove unused code
  net: ena: Improve error logging in driver
  net: ena: use build_skb() in RX path
  net: ena: add jiffies of last napi call to stats
  net: ena: Remove module param and change message severity
  net: ena: fix RST format in ENA documentation file
  net: ena: aggregate doorbell common operations into a function
  net: ena: Use dev_alloc() in RX buffer allocation
  net: ena: re-organize code to improve readability

 .../device_drivers/ethernet/amazon/ena.rst    | 164 +++++++------
 .../net/ethernet/amazon/ena/ena_admin_defs.h  |   2 -
 drivers/net/ethernet/amazon/ena/ena_com.c     |   3 +-
 drivers/net/ethernet/amazon/ena/ena_eth_com.c |  30 ++-
 drivers/net/ethernet/amazon/ena/ena_ethtool.c |  18 +-
 drivers/net/ethernet/amazon/ena/ena_netdev.c  | 216 ++++++++++--------
 drivers/net/ethernet/amazon/ena/ena_netdev.h  |  23 +-
 7 files changed, 249 insertions(+), 207 deletions(-)

-- 
2.25.1

[Patch v1 net-next 01/10] net: ena: optimize data access in fast-path code

[Shay Agroskin]

This tweaks several small places to improve the data access in fast
path:

* Remove duplicates of first_interrupt flag and surround it with
  WRITE/READ_ONCE macros:

  The flag is used to detect HW disorders in its
  interrupt communication with the driver. The flag is set when an
  interrupt is received and used in the health check function
  (ena_timer_service()) to help it find irregularities.

* Reorder some fields in ena_napi struct to take better advantage of
  cache access pattern.

* Move XDP TX queue number to a variable to save its calculation for
  every packet.

* Use likely in a condition to improve branch prediction

The 'first_interrupt' and 'interrupt_masked' flags were moved to reside
in the same cache line as the first fields of 'napi' struct. This
placement ensures that all memory accessed during upper-half handler
reside in the same cacheline (napi_schedule_irqoff() only accesses
'state' and 'poll_list' fields which are at the beginning of napi
struct).

Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
---
 drivers/net/ethernet/amazon/ena/ena_eth_com.c |  2 +-
 drivers/net/ethernet/amazon/ena/ena_netdev.c  | 23 +++++++++----------
 drivers/net/ethernet/amazon/ena/ena_netdev.h  | 11 +++++----
 3 files changed, 19 insertions(+), 17 deletions(-)

diff --git a/drivers/net/ethernet/amazon/ena/ena_eth_com.c b/drivers/net/ethernet/amazon/ena/ena_eth_com.c
index c3be751e7379..2aecd4c3de59 100644
--- a/drivers/net/ethernet/amazon/ena/ena_eth_com.c
+++ b/drivers/net/ethernet/amazon/ena/ena_eth_com.c
@@ -151,7 +151,7 @@ static int ena_com_close_bounce_buffer(struct ena_com_io_sq *io_sq)
 		return 0;
 
 	/* bounce buffer was used, so write it and get a new one */
-	if (pkt_ctrl->idx) {
+	if (likely(pkt_ctrl->idx)) {
 		rc = ena_com_write_bounce_buffer_to_dev(io_sq,
 							pkt_ctrl->curr_bounce_buf);
 		if (unlikely(rc))
diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index 881f88754bf6..b613067a06d8 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -197,7 +197,6 @@ static int ena_xdp_io_poll(struct napi_struct *napi, int budget)
 	int ret;
 
 	xdp_ring = ena_napi->xdp_ring;
-	xdp_ring->first_interrupt = ena_napi->first_interrupt;
 
 	xdp_budget = budget;
 
@@ -383,7 +382,6 @@ static int ena_xdp_execute(struct ena_ring *rx_ring, struct xdp_buff *xdp)
 	u32 verdict = XDP_PASS;
 	struct xdp_frame *xdpf;
 	u64 *xdp_stat;
-	int qid;
 
 	rcu_read_lock();
 	xdp_prog = READ_ONCE(rx_ring->xdp_bpf_prog);
@@ -404,8 +402,7 @@ static int ena_xdp_execute(struct ena_ring *rx_ring, struct xdp_buff *xdp)
 		}
 
 		/* Find xmit queue */
-		qid = rx_ring->qid + rx_ring->adapter->num_io_queues;
-		xdp_ring = &rx_ring->adapter->tx_ring[qid];
+		xdp_ring = rx_ring->xdp_ring;
 
 		/* The XDP queues are shared between XDP_TX and XDP_REDIRECT */
 		spin_lock(&xdp_ring->xdp_tx_lock);
@@ -681,7 +678,6 @@ static void ena_init_io_rings_common(struct ena_adapter *adapter,
 	ring->ena_dev = adapter->ena_dev;
 	ring->per_napi_packets = 0;
 	ring->cpu = 0;
-	ring->first_interrupt = false;
 	ring->no_interrupt_event_cnt = 0;
 	u64_stats_init(&ring->syncp);
 }
@@ -725,6 +721,7 @@ static void ena_init_io_rings(struct ena_adapter *adapter,
 				ena_com_get_nonadaptive_moderation_interval_rx(ena_dev);
 			rxr->empty_rx_queue = 0;
 			adapter->ena_napi[i].dim.mode = DIM_CQ_PERIOD_MODE_START_FROM_EQE;
+			rxr->xdp_ring = &adapter->tx_ring[i + adapter->num_io_queues];
 		}
 	}
 }
@@ -1922,9 +1919,6 @@ static int ena_io_poll(struct napi_struct *napi, int budget)
 	tx_ring = ena_napi->tx_ring;
 	rx_ring = ena_napi->rx_ring;
 
-	tx_ring->first_interrupt = ena_napi->first_interrupt;
-	rx_ring->first_interrupt = ena_napi->first_interrupt;
-
 	tx_budget = tx_ring->ring_size / ENA_TX_POLL_BUDGET_DIVIDER;
 
 	if (!test_bit(ENA_FLAG_DEV_UP, &tx_ring->adapter->flags) ||
@@ -2003,7 +1997,8 @@ static irqreturn_t ena_intr_msix_io(int irq, void *data)
 {
 	struct ena_napi *ena_napi = data;
 
-	ena_napi->first_interrupt = true;
+	/* Used to check HW health */
+	WRITE_ONCE(ena_napi->first_interrupt, true);
 
 	WRITE_ONCE(ena_napi->interrupts_masked, true);
 	smp_wmb(); /* write interrupts_masked before calling napi */
@@ -3657,7 +3652,9 @@ static void ena_fw_reset_device(struct work_struct *work)
 static int check_for_rx_interrupt_queue(struct ena_adapter *adapter,
 					struct ena_ring *rx_ring)
 {
-	if (likely(rx_ring->first_interrupt))
+	struct ena_napi *ena_napi = container_of(rx_ring->napi, struct ena_napi, napi);
+
+	if (likely(READ_ONCE(ena_napi->first_interrupt)))
 		return 0;
 
 	if (ena_com_cq_empty(rx_ring->ena_com_io_cq))
@@ -3681,6 +3678,7 @@ static int check_for_rx_interrupt_queue(struct ena_adapter *adapter,
 static int check_missing_comp_in_tx_queue(struct ena_adapter *adapter,
 					  struct ena_ring *tx_ring)
 {
+	struct ena_napi *ena_napi = container_of(tx_ring->napi, struct ena_napi, napi);
 	struct ena_tx_buffer *tx_buf;
 	unsigned long last_jiffies;
 	u32 missed_tx = 0;
@@ -3694,8 +3692,9 @@ static int check_missing_comp_in_tx_queue(struct ena_adapter *adapter,
 			/* no pending Tx at this location */
 			continue;
 
-		if (unlikely(!tx_ring->first_interrupt && time_is_before_jiffies(last_jiffies +
-			     2 * adapter->missing_tx_completion_to))) {
+		if (unlikely(!READ_ONCE(ena_napi->first_interrupt) &&
+			time_is_before_jiffies(last_jiffies + 2 *
+				adapter->missing_tx_completion_to))) {
 			/* If after graceful period interrupt is still not
 			 * received, we schedule a reset
 			 */
diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.h b/drivers/net/ethernet/amazon/ena/ena_netdev.h
index 74af15d62ee1..21758707a929 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.h
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.h
@@ -135,12 +135,12 @@ struct ena_irq {
 };
 
 struct ena_napi {
-	struct napi_struct napi ____cacheline_aligned;
+	u8 first_interrupt ____cacheline_aligned;
+	u8 interrupts_masked;
+	struct napi_struct napi;
 	struct ena_ring *tx_ring;
 	struct ena_ring *rx_ring;
 	struct ena_ring *xdp_ring;
-	bool first_interrupt;
-	bool interrupts_masked;
 	u32 qid;
 	struct dim dim;
 };
@@ -259,6 +259,10 @@ struct ena_ring {
 	struct bpf_prog *xdp_bpf_prog;
 	struct xdp_rxq_info xdp_rxq;
 	spinlock_t xdp_tx_lock;	/* synchronize XDP TX/Redirect traffic */
+	/* Used for rx queues only to point to the xdp tx ring, to
+	 * which traffic should be redirected from this rx ring.
+	 */
+	struct ena_ring *xdp_ring;
 
 	u16 next_to_use;
 	u16 next_to_clean;
@@ -271,7 +275,6 @@ struct ena_ring {
 	/* The maximum header length the device can handle */
 	u8 tx_max_header_size;
 
-	bool first_interrupt;
 	bool disable_meta_caching;
 	u16 no_interrupt_event_cnt;
 
-- 
2.25.1

[Patch v1 net-next 02/10] net: ena: Remove unused code

[Shay Agroskin]

The ENA_DEFAULT_MIN_RX_BUFF_ALLOC_SIZE macro,
ena_xdp_queues_present() function and SUSPEND_RESUME enums aren't used
in the driver, and so not needed.

Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: Gal Pressman <galpress@amazon.com>
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
---
 drivers/net/ethernet/amazon/ena/ena_admin_defs.h |  2 --
 drivers/net/ethernet/amazon/ena/ena_netdev.h     | 11 -----------
 2 files changed, 13 deletions(-)

diff --git a/drivers/net/ethernet/amazon/ena/ena_admin_defs.h b/drivers/net/ethernet/amazon/ena/ena_admin_defs.h
index 4164eacc5c28..f5ec35fa4c63 100644
--- a/drivers/net/ethernet/amazon/ena/ena_admin_defs.h
+++ b/drivers/net/ethernet/amazon/ena/ena_admin_defs.h
@@ -1042,8 +1042,6 @@ enum ena_admin_aenq_group {
 };
 
 enum ena_admin_aenq_notification_syndrome {
-	ENA_ADMIN_SUSPEND                           = 0,
-	ENA_ADMIN_RESUME                            = 1,
 	ENA_ADMIN_UPDATE_HINTS                      = 2,
 };
 
diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.h b/drivers/net/ethernet/amazon/ena/ena_netdev.h
index 21758707a929..834348fcdf3c 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.h
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.h
@@ -55,12 +55,6 @@
 #define ENA_TX_WAKEUP_THRESH		(MAX_SKB_FRAGS + 2)
 #define ENA_DEFAULT_RX_COPYBREAK	(256 - NET_IP_ALIGN)
 
-/* limit the buffer size to 600 bytes to handle MTU changes from very
- * small to very large, in which case the number of buffers per packet
- * could exceed ENA_PKT_MAX_BUFS
- */
-#define ENA_DEFAULT_MIN_RX_BUFF_ALLOC_SIZE 600
-
 #define ENA_MIN_MTU		128
 
 #define ENA_NAME_MAX_LEN	20
@@ -417,11 +411,6 @@ enum ena_xdp_errors_t {
 	ENA_XDP_NO_ENOUGH_QUEUES,
 };
 
-static inline bool ena_xdp_queues_present(struct ena_adapter *adapter)
-{
-	return adapter->xdp_first_ring != 0;
-}
-
 static inline bool ena_xdp_present(struct ena_adapter *adapter)
 {
 	return !!adapter->xdp_bpf_prog;
-- 
2.25.1

[Patch v1 net-next 03/10] net: ena: Improve error logging in driver

[Shay Agroskin]

Add prints to improve logging of driver's errors.

Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
---
 drivers/net/ethernet/amazon/ena/ena_eth_com.c | 28 +++++++++++++++----
 1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/amazon/ena/ena_eth_com.c b/drivers/net/ethernet/amazon/ena/ena_eth_com.c
index 2aecd4c3de59..3d6f0a466a9e 100644
--- a/drivers/net/ethernet/amazon/ena/ena_eth_com.c
+++ b/drivers/net/ethernet/amazon/ena/ena_eth_com.c
@@ -154,8 +154,11 @@ static int ena_com_close_bounce_buffer(struct ena_com_io_sq *io_sq)
 	if (likely(pkt_ctrl->idx)) {
 		rc = ena_com_write_bounce_buffer_to_dev(io_sq,
 							pkt_ctrl->curr_bounce_buf);
-		if (unlikely(rc))
+		if (unlikely(rc)) {
+			netdev_err(ena_com_io_sq_to_ena_dev(io_sq)->net_device,
+				   "Failed to write bounce buffer to device\n");
 			return rc;
+		}
 
 		pkt_ctrl->curr_bounce_buf =
 			ena_com_get_next_bounce_buffer(&io_sq->bounce_buf_ctrl);
@@ -185,8 +188,11 @@ static int ena_com_sq_update_llq_tail(struct ena_com_io_sq *io_sq)
 	if (!pkt_ctrl->descs_left_in_line) {
 		rc = ena_com_write_bounce_buffer_to_dev(io_sq,
 							pkt_ctrl->curr_bounce_buf);
-		if (unlikely(rc))
+		if (unlikely(rc)) {
+			netdev_err(ena_com_io_sq_to_ena_dev(io_sq)->net_device,
+				   "Failed to write bounce buffer to device\n");
 			return rc;
+		}
 
 		pkt_ctrl->curr_bounce_buf =
 			ena_com_get_next_bounce_buffer(&io_sq->bounce_buf_ctrl);
@@ -406,8 +412,11 @@ int ena_com_prepare_tx(struct ena_com_io_sq *io_sq,
 	}
 
 	if (unlikely(io_sq->mem_queue_type == ENA_ADMIN_PLACEMENT_POLICY_DEV &&
-		     !buffer_to_push))
+		     !buffer_to_push)) {
+		netdev_err(ena_com_io_sq_to_ena_dev(io_sq)->net_device,
+			   "Push header wasn't provided in LLQ mode\n");
 		return -EINVAL;
+	}
 
 	rc = ena_com_write_header_to_bounce(io_sq, buffer_to_push, header_len);
 	if (unlikely(rc))
@@ -423,6 +432,9 @@ int ena_com_prepare_tx(struct ena_com_io_sq *io_sq,
 	/* If the caller doesn't want to send packets */
 	if (unlikely(!num_bufs && !header_len)) {
 		rc = ena_com_close_bounce_buffer(io_sq);
+		if (rc)
+			netdev_err(ena_com_io_sq_to_ena_dev(io_sq)->net_device,
+				   "Failed to write buffers to LLQ\n");
 		*nb_hw_desc = io_sq->tail - start_tail;
 		return rc;
 	}
@@ -482,8 +494,11 @@ int ena_com_prepare_tx(struct ena_com_io_sq *io_sq,
 		/* The first desc share the same desc as the header */
 		if (likely(i != 0)) {
 			rc = ena_com_sq_update_tail(io_sq);
-			if (unlikely(rc))
+			if (unlikely(rc)) {
+				netdev_err(ena_com_io_sq_to_ena_dev(io_sq)->net_device,
+					   "Failed to update sq tail\n");
 				return rc;
+			}
 
 			desc = get_sq_desc(io_sq);
 			if (unlikely(!desc))
@@ -512,8 +527,11 @@ int ena_com_prepare_tx(struct ena_com_io_sq *io_sq,
 	desc->len_ctrl |= ENA_ETH_IO_TX_DESC_LAST_MASK;
 
 	rc = ena_com_sq_update_tail(io_sq);
-	if (unlikely(rc))
+	if (unlikely(rc)) {
+		netdev_err(ena_com_io_sq_to_ena_dev(io_sq)->net_device,
+			   "Failed to update sq tail of the last descriptor\n");
 		return rc;
+	}
 
 	rc = ena_com_close_bounce_buffer(io_sq);
 
-- 
2.25.1

[Patch v1 net-next 04/10] net: ena: use build_skb() in RX path

[Shay Agroskin]

This patch converts the RX path to use build_skb() for packets larger
than copybreak (set to 256 by default). This function makes the first
descriptor's page to be the linear part of the sk_buff struct buffer.

Also remove the SKB description from the README since most of it no
longer relevant and the parts that are left don't add information.

Signed-off-by: Shay Agroskin <shayagr@amazon.com>
---
 drivers/net/ethernet/amazon/ena/ena_netdev.c | 66 ++++++++++++--------
 1 file changed, 41 insertions(+), 25 deletions(-)

diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index b613067a06d8..d7bc4f45e5df 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -529,7 +529,7 @@ static void ena_xdp_exchange_program_rx_in_range(struct ena_adapter *adapter,
 			rx_ring->rx_headroom = XDP_PACKET_HEADROOM;
 		} else {
 			ena_xdp_unregister_rxq_info(rx_ring);
-			rx_ring->rx_headroom = 0;
+			rx_ring->rx_headroom = NET_SKB_PAD;
 		}
 	}
 }
@@ -720,6 +720,7 @@ static void ena_init_io_rings(struct ena_adapter *adapter,
 			rxr->smoothed_interval =
 				ena_com_get_nonadaptive_moderation_interval_rx(ena_dev);
 			rxr->empty_rx_queue = 0;
+			rxr->rx_headroom = NET_SKB_PAD;
 			adapter->ena_napi[i].dim.mode = DIM_CQ_PERIOD_MODE_START_FROM_EQE;
 			rxr->xdp_ring = &adapter->tx_ring[i + adapter->num_io_queues];
 		}
@@ -982,6 +983,7 @@ static int ena_alloc_rx_page(struct ena_ring *rx_ring,
 	struct ena_com_buf *ena_buf;
 	struct page *page;
 	dma_addr_t dma;
+	int tailroom;
 
 	/* restore page offset value in case it has been changed by device */
 	rx_info->page_offset = headroom;
@@ -1012,10 +1014,12 @@ static int ena_alloc_rx_page(struct ena_ring *rx_ring,
 	netif_dbg(rx_ring->adapter, rx_status, rx_ring->netdev,
 		  "Allocate page %p, rx_info %p\n", page, rx_info);
 
+	tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+
 	rx_info->page = page;
 	ena_buf = &rx_info->ena_buf;
 	ena_buf->paddr = dma + headroom;
-	ena_buf->len = ENA_PAGE_SIZE - headroom;
+	ena_buf->len = ENA_PAGE_SIZE - headroom - tailroom;
 
 	return 0;
 }
@@ -1381,21 +1385,23 @@ static int ena_clean_tx_irq(struct ena_ring *tx_ring, u32 budget)
 	return tx_pkts;
 }
 
-static struct sk_buff *ena_alloc_skb(struct ena_ring *rx_ring, bool frags)
+static struct sk_buff *ena_alloc_skb(struct ena_ring *rx_ring, void *first_frag)
 {
 	struct sk_buff *skb;
 
-	if (frags)
-		skb = napi_get_frags(rx_ring->napi);
-	else
+	if (!first_frag)
 		skb = netdev_alloc_skb_ip_align(rx_ring->netdev,
 						rx_ring->rx_copybreak);
+	else
+		skb = build_skb(first_frag, ENA_PAGE_SIZE);
 
 	if (unlikely(!skb)) {
 		ena_increase_stat(&rx_ring->rx_stats.skb_alloc_fail, 1,
 				  &rx_ring->syncp);
+
 		netif_dbg(rx_ring->adapter, rx_err, rx_ring->netdev,
-			  "Failed to allocate skb. frags: %d\n", frags);
+			  "Failed to allocate skb. first_frag %s\n",
+			  first_frag ? "provided" : "not provided");
 		return NULL;
 	}
 
@@ -1410,7 +1416,9 @@ static struct sk_buff *ena_rx_skb(struct ena_ring *rx_ring,
 	struct sk_buff *skb;
 	struct ena_rx_buffer *rx_info;
 	u16 len, req_id, buf = 0;
-	void *va;
+	void *page_addr;
+	u32 page_offset;
+	void *data_addr;
 
 	len = ena_bufs[buf].len;
 	req_id = ena_bufs[buf].req_id;
@@ -1428,12 +1436,14 @@ static struct sk_buff *ena_rx_skb(struct ena_ring *rx_ring,
 		  rx_info, rx_info->page);
 
 	/* save virt address of first buffer */
-	va = page_address(rx_info->page) + rx_info->page_offset;
+	page_addr = page_address(rx_info->page);
+	page_offset = rx_info->page_offset;
+	data_addr = page_addr + page_offset;
 
-	prefetch(va);
+	prefetch(data_addr);
 
 	if (len <= rx_ring->rx_copybreak) {
-		skb = ena_alloc_skb(rx_ring, false);
+		skb = ena_alloc_skb(rx_ring, NULL);
 		if (unlikely(!skb))
 			return NULL;
 
@@ -1446,7 +1456,7 @@ static struct sk_buff *ena_rx_skb(struct ena_ring *rx_ring,
 					dma_unmap_addr(&rx_info->ena_buf, paddr),
 					len,
 					DMA_FROM_DEVICE);
-		skb_copy_to_linear_data(skb, va, len);
+		skb_copy_to_linear_data(skb, data_addr, len);
 		dma_sync_single_for_device(rx_ring->dev,
 					   dma_unmap_addr(&rx_info->ena_buf, paddr),
 					   len,
@@ -1460,16 +1470,18 @@ static struct sk_buff *ena_rx_skb(struct ena_ring *rx_ring,
 		return skb;
 	}
 
-	skb = ena_alloc_skb(rx_ring, true);
+	ena_unmap_rx_buff(rx_ring, rx_info);
+
+	skb = ena_alloc_skb(rx_ring, page_addr);
 	if (unlikely(!skb))
 		return NULL;
 
-	do {
-		ena_unmap_rx_buff(rx_ring, rx_info);
-
-		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_info->page,
-				rx_info->page_offset, len, ENA_PAGE_SIZE);
+	/* Populate skb's linear part */
+	skb_reserve(skb, page_offset);
+	skb_put(skb, len);
+	skb->protocol = eth_type_trans(skb, rx_ring->netdev);
 
+	do {
 		netif_dbg(rx_ring->adapter, rx_status, rx_ring->netdev,
 			  "RX skb updated. len %d. data_len %d\n",
 			  skb->len, skb->data_len);
@@ -1488,6 +1500,12 @@ static struct sk_buff *ena_rx_skb(struct ena_ring *rx_ring,
 		req_id = ena_bufs[buf].req_id;
 
 		rx_info = &rx_ring->rx_buffer_info[req_id];
+
+		ena_unmap_rx_buff(rx_ring, rx_info);
+
+		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_info->page,
+				rx_info->page_offset, len, ENA_PAGE_SIZE);
+
 	} while (1);
 
 	return skb;
@@ -1700,14 +1718,12 @@ static int ena_clean_rx_irq(struct ena_ring *rx_ring, struct napi_struct *napi,
 
 		skb_record_rx_queue(skb, rx_ring->qid);
 
-		if (rx_ring->ena_bufs[0].len <= rx_ring->rx_copybreak) {
-			total_len += rx_ring->ena_bufs[0].len;
+		if (rx_ring->ena_bufs[0].len <= rx_ring->rx_copybreak)
 			rx_copybreak_pkt++;
-			napi_gro_receive(napi, skb);
-		} else {
-			total_len += skb->len;
-			napi_gro_frags(napi);
-		}
+
+		total_len += skb->len;
+
+		napi_gro_receive(napi, skb);
 
 		res_budget--;
 	} while (likely(res_budget));
-- 
2.25.1

[Patch v1 net-next 05/10] net: ena: add jiffies of last napi call to stats

[Shay Agroskin]

There are instances when we want to know when the last napi was
called for debugging.

On stuck / heavy loaded CPUs, the ena napi handler might not be
called for a long period of time. This stat can help us to
determine how much time passed since the last execution of napi.

Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
---
 drivers/net/ethernet/amazon/ena/ena_netdev.c | 28 ++++++++++++++------
 drivers/net/ethernet/amazon/ena/ena_netdev.h |  1 +
 2 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index d7bc4f45e5df..f013fa312937 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -228,6 +228,7 @@ static int ena_xdp_io_poll(struct napi_struct *napi, int budget)
 	xdp_ring->tx_stats.napi_comp += napi_comp_call;
 	xdp_ring->tx_stats.tx_poll++;
 	u64_stats_update_end(&xdp_ring->syncp);
+	xdp_ring->tx_stats.last_napi_jiffies = jiffies;
 
 	return ret;
 }
@@ -1989,6 +1990,8 @@ static int ena_io_poll(struct napi_struct *napi, int budget)
 	tx_ring->tx_stats.tx_poll++;
 	u64_stats_update_end(&tx_ring->syncp);
 
+	tx_ring->tx_stats.last_napi_jiffies = jiffies;
+
 	return ret;
 }
 
@@ -3695,6 +3698,9 @@ static int check_missing_comp_in_tx_queue(struct ena_adapter *adapter,
 					  struct ena_ring *tx_ring)
 {
 	struct ena_napi *ena_napi = container_of(tx_ring->napi, struct ena_napi, napi);
+	unsigned int time_since_last_napi;
+	unsigned int missing_tx_comp_to;
+	bool is_tx_comp_time_expired;
 	struct ena_tx_buffer *tx_buf;
 	unsigned long last_jiffies;
 	u32 missed_tx = 0;
@@ -3708,9 +3714,10 @@ static int check_missing_comp_in_tx_queue(struct ena_adapter *adapter,
 			/* no pending Tx at this location */
 			continue;
 
-		if (unlikely(!READ_ONCE(ena_napi->first_interrupt) &&
-			time_is_before_jiffies(last_jiffies + 2 *
-				adapter->missing_tx_completion_to))) {
+		is_tx_comp_time_expired = time_is_before_jiffies(last_jiffies +
+			 2 * adapter->missing_tx_completion_to);
+
+		if (unlikely(!READ_ONCE(ena_napi->first_interrupt) && is_tx_comp_time_expired)) {
 			/* If after graceful period interrupt is still not
 			 * received, we schedule a reset
 			 */
@@ -3723,12 +3730,17 @@ static int check_missing_comp_in_tx_queue(struct ena_adapter *adapter,
 			return -EIO;
 		}
 
-		if (unlikely(time_is_before_jiffies(last_jiffies +
-				adapter->missing_tx_completion_to))) {
-			if (!tx_buf->print_once)
+		is_tx_comp_time_expired = time_is_before_jiffies(last_jiffies +
+			adapter->missing_tx_completion_to);
+
+		if (unlikely(is_tx_comp_time_expired)) {
+			if (!tx_buf->print_once) {
+				time_since_last_napi = jiffies_to_usecs(jiffies - tx_ring->tx_stats.last_napi_jiffies);
+				missing_tx_comp_to = jiffies_to_msecs(adapter->missing_tx_completion_to);
 				netif_notice(adapter, tx_err, adapter->netdev,
-					     "Found a Tx that wasn't completed on time, qid %d, index %d.\n",
-					     tx_ring->qid, i);
+					     "Found a Tx that wasn't completed on time, qid %d, index %d. %u usecs have passed since last napi execution. Missing Tx timeout value %u msecs\n",
+					     tx_ring->qid, i, time_since_last_napi, missing_tx_comp_to);
+			}
 
 			tx_buf->print_once = 1;
 			missed_tx++;
diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.h b/drivers/net/ethernet/amazon/ena/ena_netdev.h
index 834348fcdf3c..0c39fc2fa345 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.h
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.h
@@ -206,6 +206,7 @@ struct ena_stats_tx {
 	u64 llq_buffer_copy;
 	u64 missed_tx;
 	u64 unmask_interrupt;
+	u64 last_napi_jiffies;
 };
 
 struct ena_stats_rx {
-- 
2.25.1

[Patch v1 net-next 06/10] net: ena: Remove module param and change message severity

[Shay Agroskin]

Remove the module param 'debug' which allows to specify the message
level of the driver. This value can be specified using ethtool command.
Also reduce the message level of LLQ support to be a warning since it is
not an indication of an error.

Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
---
 drivers/net/ethernet/amazon/ena/ena_netdev.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index f013fa312937..6e648b6882b7 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -35,9 +35,6 @@ MODULE_LICENSE("GPL");
 
 #define DEFAULT_MSG_ENABLE (NETIF_MSG_DRV | NETIF_MSG_PROBE | NETIF_MSG_IFUP | \
 		NETIF_MSG_TX_DONE | NETIF_MSG_TX_ERR | NETIF_MSG_RX_ERR)
-static int debug = -1;
-module_param(debug, int, 0);
-MODULE_PARM_DESC(debug, "Debug level (0=none,...,16=all)");
 
 static struct ena_aenq_handlers aenq_handlers;
 
@@ -3360,7 +3357,7 @@ static int ena_set_queues_placement_policy(struct pci_dev *pdev,
 
 	llq_feature_mask = 1 << ENA_ADMIN_LLQ;
 	if (!(ena_dev->supported_features & llq_feature_mask)) {
-		dev_err(&pdev->dev,
+		dev_warn(&pdev->dev,
 			"LLQ is not supported Fallback to host mode policy.\n");
 		ena_dev->tx_mem_queue_type = ENA_ADMIN_PLACEMENT_POLICY_HOST;
 		return 0;
@@ -4271,7 +4268,7 @@ static int ena_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	adapter->ena_dev = ena_dev;
 	adapter->netdev = netdev;
 	adapter->pdev = pdev;
-	adapter->msg_enable = netif_msg_init(debug, DEFAULT_MSG_ENABLE);
+	adapter->msg_enable = DEFAULT_MSG_ENABLE;
 
 	ena_dev->net_device = netdev;
 
-- 
2.25.1

[Patch v1 net-next 07/10] net: ena: fix RST format in ENA documentation file

[Shay Agroskin]

The documentation file used to be written in markdown format but was
converted to reStructuredText (rst).

The converted file doesn't keep up with rst format requirements which
results in hard-to-read text.

This patch fixes the formatting of the file. The patch also
* Highlights and emphasizes some lines to improve readability
* Rephrases some hard-to-understand text
* Updates outdated function descriptions.
* Removes TSO description which falsely claims the driver supports it

Signed-off-by: Shay Agroskin <shayagr@amazon.com>
---
 .../device_drivers/ethernet/amazon/ena.rst    | 164 +++++++++---------
 1 file changed, 78 insertions(+), 86 deletions(-)

diff --git a/Documentation/networking/device_drivers/ethernet/amazon/ena.rst b/Documentation/networking/device_drivers/ethernet/amazon/ena.rst
index f8c6469f2bd2..01b2a69b0cb0 100644
--- a/Documentation/networking/device_drivers/ethernet/amazon/ena.rst
+++ b/Documentation/networking/device_drivers/ethernet/amazon/ena.rst
@@ -11,12 +11,12 @@ ENA is a networking interface designed to make good use of modern CPU
 features and system architectures.
 
 The ENA device exposes a lightweight management interface with a
-minimal set of memory mapped registers and extendable command set
+minimal set of memory mapped registers and extendible command set
 through an Admin Queue.
 
 The driver supports a range of ENA devices, is link-speed independent
-(i.e., the same driver is used for 10GbE, 25GbE, 40GbE, etc.), and has
-a negotiated and extendable feature set.
+(i.e., the same driver is used for 10GbE, 25GbE, 40GbE, etc), and has
+a negotiated and extendible feature set.
 
 Some ENA devices support SR-IOV. This driver is used for both the
 SR-IOV Physical Function (PF) and Virtual Function (VF) devices.
@@ -27,9 +27,9 @@ is advertised by the device via the Admin Queue), a dedicated MSI-X
 interrupt vector per Tx/Rx queue pair, adaptive interrupt moderation,
 and CPU cacheline optimized data placement.
 
-The ENA driver supports industry standard TCP/IP offload features such
-as checksum offload and TCP transmit segmentation offload (TSO).
-Receive-side scaling (RSS) is supported for multi-core scaling.
+The ENA driver supports industry standard TCP/IP offload features such as
+checksum offload. Receive-side scaling (RSS) is supported for multi-core
+scaling.
 
 The ENA driver and its corresponding devices implement health
 monitoring mechanisms such as watchdog, enabling the device and driver
@@ -38,22 +38,20 @@ debug logs.
 
 Some of the ENA devices support a working mode called Low-latency
 Queue (LLQ), which saves several more microseconds.
-
 ENA Source Code Directory Structure
 ===================================
 
 =================   ======================================================
 ena_com.[ch]        Management communication layer. This layer is
-		    responsible for the handling all the management
-		    (admin) communication between the device and the
-		    driver.
+                    responsible for the handling all the management
+                    (admin) communication between the device and the
+                    driver.
 ena_eth_com.[ch]    Tx/Rx data path.
 ena_admin_defs.h    Definition of ENA management interface.
 ena_eth_io_defs.h   Definition of ENA data path interface.
 ena_common_defs.h   Common definitions for ena_com layer.
 ena_regs_defs.h     Definition of ENA PCI memory-mapped (MMIO) registers.
 ena_netdev.[ch]     Main Linux kernel driver.
-ena_syfsfs.[ch]     Sysfs files.
 ena_ethtool.c       ethtool callbacks.
 ena_pci_id_tbl.h    Supported device IDs.
 =================   ======================================================
@@ -69,7 +67,7 @@ ENA management interface is exposed by means of:
 - Asynchronous Event Notification Queue (AENQ)
 
 ENA device MMIO Registers are accessed only during driver
-initialization and are not involved in further normal device
+initialization and are not used during further normal device
 operation.
 
 AQ is used for submitting management commands, and the
@@ -100,28 +98,27 @@ group may have multiple syndromes, as shown below
 
 The events are:
 
-	====================	===============
-	Group			Syndrome
-	====================	===============
-	Link state change	**X**
-	Fatal error		**X**
-	Notification		Suspend traffic
-	Notification		Resume traffic
-	Keep-Alive		**X**
-	====================	===============
+====================    ===============
+Group                   Syndrome
+====================    ===============
+Link state change       **X**
+Fatal error             **X**
+Notification            Suspend traffic
+Notification            Resume traffic
+Keep-Alive              **X**
+====================    ===============
 
 ACQ and AENQ share the same MSI-X vector.
 
-Keep-Alive is a special mechanism that allows monitoring of the
-device's health. The driver maintains a watchdog (WD) handler which,
-if fired, logs the current state and statistics then resets and
-restarts the ENA device and driver. A Keep-Alive event is delivered by
-the device every second. The driver re-arms the WD upon reception of a
-Keep-Alive event. A missed Keep-Alive event causes the WD handler to
-fire.
+Keep-Alive is a special mechanism that allows monitoring the device's health.
+A Keep-Alive event is delivered by the device every second.
+The driver maintains a watchdog (WD) handler which logs the current state and
+statistics. If the keep-alive events aren't delivered as expected the WD resets
+the device and the driver.
 
 Data Path Interface
 ===================
+
 I/O operations are based on Tx and Rx Submission Queues (Tx SQ and Rx
 SQ correspondingly). Each SQ has a completion queue (CQ) associated
 with it.
@@ -131,26 +128,24 @@ physical memory.
 
 The ENA driver supports two Queue Operation modes for Tx SQs:
 
-- Regular mode
+- **Regular mode:**
+  In this mode the Tx SQs reside in the host's memory. The ENA
+  device fetches the ENA Tx descriptors and packet data from host
+  memory.
 
-  * In this mode the Tx SQs reside in the host's memory. The ENA
-    device fetches the ENA Tx descriptors and packet data from host
-    memory.
+- **Low Latency Queue (LLQ) mode or "push-mode":**
+  In this mode the driver pushes the transmit descriptors and the
+  first 128 bytes of the packet directly to the ENA device memory
+  space. The rest of the packet payload is fetched by the
+  device. For this operation mode, the driver uses a dedicated PCI
+  device memory BAR, which is mapped with write-combine capability.
 
-- Low Latency Queue (LLQ) mode or "push-mode".
-
-  * In this mode the driver pushes the transmit descriptors and the
-    first 128 bytes of the packet directly to the ENA device memory
-    space. The rest of the packet payload is fetched by the
-    device. For this operation mode, the driver uses a dedicated PCI
-    device memory BAR, which is mapped with write-combine capability.
+  **Note that** not all ENA devices support LLQ, and this feature is negotiated
+  with the device upon initialization. If the ENA device does not
+  support LLQ mode, the driver falls back to the regular mode.
 
 The Rx SQs support only the regular mode.
 
-Note: Not all ENA devices support LLQ, and this feature is negotiated
-      with the device upon initialization. If the ENA device does not
-      support LLQ mode, the driver falls back to the regular mode.
-
 The driver supports multi-queue for both Tx and Rx. This has various
 benefits:
 
@@ -165,6 +160,7 @@ benefits:
 
 Interrupt Modes
 ===============
+
 The driver assigns a single MSI-X vector per queue pair (for both Tx
 and Rx directions). The driver assigns an additional dedicated MSI-X vector
 for management (for ACQ and AENQ).
@@ -190,20 +186,21 @@ unmasked by the driver after NAPI processing is complete.
 
 Interrupt Moderation
 ====================
+
 ENA driver and device can operate in conventional or adaptive interrupt
 moderation mode.
 
-In conventional mode the driver instructs device to postpone interrupt
+**In conventional mode** the driver instructs device to postpone interrupt
 posting according to static interrupt delay value. The interrupt delay
-value can be configured through ethtool(8). The following ethtool
-parameters are supported by the driver: tx-usecs, rx-usecs
+value can be configured through `ethtool(8)`. The following `ethtool`
+parameters are supported by the driver: ``tx-usecs``, ``rx-usecs``
 
-In adaptive interrupt moderation mode the interrupt delay value is
+**In adaptive interrupt** moderation mode the interrupt delay value is
 updated by the driver dynamically and adjusted every NAPI cycle
 according to the traffic nature.
 
-Adaptive coalescing can be switched on/off through ethtool(8)
-adaptive_rx on|off parameter.
+Adaptive coalescing can be switched on/off through `ethtool(8)`'s
+:code:`adaptive_rx on|off` parameter.
 
 More information about Adaptive Interrupt Moderation (DIM) can be found in
 Documentation/networking/net_dim.rst
@@ -214,17 +211,10 @@ The rx_copybreak is initialized by default to ENA_DEFAULT_RX_COPYBREAK
 and can be configured by the ETHTOOL_STUNABLE command of the
 SIOCETHTOOL ioctl.
 
-SKB
-===
-The driver-allocated SKB for frames received from Rx handling using
-NAPI context. The allocation method depends on the size of the packet.
-If the frame length is larger than rx_copybreak, napi_get_frags()
-is used, otherwise netdev_alloc_skb_ip_align() is used, the buffer
-content is copied (by CPU) to the SKB, and the buffer is recycled.
-
 Statistics
 ==========
-The user can obtain ENA device and driver statistics using ethtool.
+
+The user can obtain ENA device and driver statistics using `ethtool`.
 The driver can collect regular or extended statistics (including
 per-queue stats) from the device.
 
@@ -232,22 +222,23 @@ In addition the driver logs the stats to syslog upon device reset.
 
 MTU
 ===
+
 The driver supports an arbitrarily large MTU with a maximum that is
 negotiated with the device. The driver configures MTU using the
 SetFeature command (ENA_ADMIN_MTU property). The user can change MTU
-via ip(8) and similar legacy tools.
+via `ip(8)` and similar legacy tools.
 
 Stateless Offloads
 ==================
+
 The ENA driver supports:
 
-- TSO over IPv4/IPv6
-- TSO with ECN
 - IPv4 header checksum offload
 - TCP/UDP over IPv4/IPv6 checksum offloads
 
 RSS
 ===
+
 - The ENA device supports RSS that allows flexible Rx traffic
   steering.
 - Toeplitz and CRC32 hash functions are supported.
@@ -260,41 +251,42 @@ RSS
   function delivered in the Rx CQ descriptor is set in the received
   SKB.
 - The user can provide a hash key, hash function, and configure the
-  indirection table through ethtool(8).
+  indirection table through `ethtool(8)`.
 
 DATA PATH
 =========
+
 Tx
 --
 
-ena_start_xmit() is called by the stack. This function does the following:
+:code:`ena_start_xmit()` is called by the stack. This function does the following:
 
-- Maps data buffers (skb->data and frags).
-- Populates ena_buf for the push buffer (if the driver and device are
-  in push mode.)
+- Maps data buffers (``skb->data`` and frags).
+- Populates ``ena_buf`` for the push buffer (if the driver and device are
+  in push mode).
 - Prepares ENA bufs for the remaining frags.
-- Allocates a new request ID from the empty req_id ring. The request
+- Allocates a new request ID from the empty ``req_id`` ring. The request
   ID is the index of the packet in the Tx info. This is used for
-  out-of-order TX completions.
+  out-of-order Tx completions.
 - Adds the packet to the proper place in the Tx ring.
-- Calls ena_com_prepare_tx(), an ENA communication layer that converts
-  the ena_bufs to ENA descriptors (and adds meta ENA descriptors as
-  needed.)
+- Calls :code:`ena_com_prepare_tx()`, an ENA communication layer that converts
+  the ``ena_bufs`` to ENA descriptors (and adds meta ENA descriptors as
+  needed).
 
   * This function also copies the ENA descriptors and the push buffer
-    to the Device memory space (if in push mode.)
+    to the Device memory space (if in push mode).
 
-- Writes doorbell to the ENA device.
+- Writes a doorbell to the ENA device.
 - When the ENA device finishes sending the packet, a completion
   interrupt is raised.
 - The interrupt handler schedules NAPI.
-- The ena_clean_tx_irq() function is called. This function handles the
+- The :code:`ena_clean_tx_irq()` function is called. This function handles the
   completion descriptors generated by the ENA, with a single
   completion descriptor per completed packet.
 
-  * req_id is retrieved from the completion descriptor. The tx_info of
-    the packet is retrieved via the req_id. The data buffers are
-    unmapped and req_id is returned to the empty req_id ring.
+  * ``req_id`` is retrieved from the completion descriptor. The ``tx_info`` of
+    the packet is retrieved via the ``req_id``. The data buffers are
+    unmapped and ``req_id`` is returned to the empty ``req_id`` ring.
   * The function stops when the completion descriptors are completed or
     the budget is reached.
 
@@ -303,12 +295,11 @@ Rx
 
 - When a packet is received from the ENA device.
 - The interrupt handler schedules NAPI.
-- The ena_clean_rx_irq() function is called. This function calls
-  ena_rx_pkt(), an ENA communication layer function, which returns the
-  number of descriptors used for a new unhandled packet, and zero if
+- The :code:`ena_clean_rx_irq()` function is called. This function calls
+  :code:`ena_com_rx_pkt()`, an ENA communication layer function, which returns the
+  number of descriptors used for a new packet, and zero if
   no new packet is found.
-- Then it calls the ena_clean_rx_irq() function.
-- ena_eth_rx_skb() checks packet length:
+- :code:`ena_rx_skb()` checks packet length:
 
   * If the packet is small (len < rx_copybreak), the driver allocates
     a SKB for the new packet, and copies the packet payload into the
@@ -317,9 +308,10 @@ Rx
     - In this way the original data buffer is not passed to the stack
       and is reused for future Rx packets.
 
-  * Otherwise the function unmaps the Rx buffer, then allocates the
-    new SKB structure and hooks the Rx buffer to the SKB frags.
+  * Otherwise the function unmaps the Rx buffer, sets the first
+    descriptor as `skb`'s linear part and the other descriptors as the
+    `skb`'s frags.
 
 - The new SKB is updated with the necessary information (protocol,
-  checksum hw verify result, etc.), and then passed to the network
-  stack, using the NAPI interface function napi_gro_receive().
+  checksum hw verify result, etc), and then passed to the network
+  stack, using the NAPI interface function :code:`napi_gro_receive()`.
-- 
2.25.1

[Patch v1 net-next 08/10] net: ena: aggregate doorbell common operations into a function

[Shay Agroskin]

The ena_ring_tx_doorbell() is introduced to call the doorbell and
increase the driver's corresponding stat.

Signed-off-by: Ido Segev <idose@amazon.com>
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
---
 drivers/net/ethernet/amazon/ena/ena_netdev.c | 38 ++++++++++----------
 1 file changed, 18 insertions(+), 20 deletions(-)

diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index 6e648b6882b7..37c839401c6c 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -86,6 +86,12 @@ static void ena_increase_stat(u64 *statp, u64 cnt,
 	u64_stats_update_end(syncp);
 }
 
+static void ena_ring_tx_doorbell(struct ena_ring *tx_ring)
+{
+	ena_com_write_sq_doorbell(tx_ring->ena_com_io_sq);
+	ena_increase_stat(&tx_ring->tx_stats.doorbells, 1, &tx_ring->syncp);
+}
+
 static void ena_tx_timeout(struct net_device *dev, unsigned int txqueue)
 {
 	struct ena_adapter *adapter = netdev_priv(dev);
@@ -144,7 +150,7 @@ static int ena_xmit_common(struct net_device *dev,
 		netif_dbg(adapter, tx_queued, dev,
 			  "llq tx max burst size of queue %d achieved, writing doorbell to send burst\n",
 			  ring->qid);
-		ena_com_write_sq_doorbell(ring->ena_com_io_sq);
+		ena_ring_tx_doorbell(ring);
 	}
 
 	/* prepare the packet's descriptors to dma engine */
@@ -313,14 +319,12 @@ static int ena_xdp_xmit_frame(struct ena_ring *xdp_ring,
 			     xdpf->len);
 	if (rc)
 		goto error_unmap_dma;
-	/* trigger the dma engine. ena_com_write_sq_doorbell()
-	 * has a mb
+
+	/* trigger the dma engine. ena_ring_tx_doorbell()
+	 * calls a memory barrier inside it.
 	 */
-	if (flags & XDP_XMIT_FLUSH) {
-		ena_com_write_sq_doorbell(xdp_ring->ena_com_io_sq);
-		ena_increase_stat(&xdp_ring->tx_stats.doorbells, 1,
-				  &xdp_ring->syncp);
-	}
+	if (flags & XDP_XMIT_FLUSH)
+		ena_ring_tx_doorbell(xdp_ring);
 
 	return rc;
 
@@ -361,11 +365,8 @@ static int ena_xdp_xmit(struct net_device *dev, int n,
 	}
 
 	/* Ring doorbell to make device aware of the packets */
-	if (flags & XDP_XMIT_FLUSH) {
-		ena_com_write_sq_doorbell(xdp_ring->ena_com_io_sq);
-		ena_increase_stat(&xdp_ring->tx_stats.doorbells, 1,
-				  &xdp_ring->syncp);
-	}
+	if (flags & XDP_XMIT_FLUSH)
+		ena_ring_tx_doorbell(xdp_ring);
 
 	spin_unlock(&xdp_ring->xdp_tx_lock);
 
@@ -3100,14 +3101,11 @@ static netdev_tx_t ena_start_xmit(struct sk_buff *skb, struct net_device *dev)
 		}
 	}
 
-	if (netif_xmit_stopped(txq) || !netdev_xmit_more()) {
-		/* trigger the dma engine. ena_com_write_sq_doorbell()
-		 * has a mb
+	if (netif_xmit_stopped(txq) || !netdev_xmit_more())
+		/* trigger the dma engine. ena_ring_tx_doorbell()
+		 * calls a memory barrier inside it.
 		 */
-		ena_com_write_sq_doorbell(tx_ring->ena_com_io_sq);
-		ena_increase_stat(&tx_ring->tx_stats.doorbells, 1,
-				  &tx_ring->syncp);
-	}
+		ena_ring_tx_doorbell(tx_ring);
 
 	return NETDEV_TX_OK;
 
-- 
2.25.1

[Patch v1 net-next 09/10] net: ena: Use dev_alloc() in RX buffer allocation

[Shay Agroskin]

Use dev_alloc() when allocating RX buffers instead of specifying the
allocation flags explicitly. This result in same behaviour with less
code.

Also move the page allocation and its DMA mapping into a function. This
creates a logical block, which may help understanding the code.

Signed-off-by: Shay Agroskin <shayagr@amazon.com>
---
 drivers/net/ethernet/amazon/ena/ena_netdev.c | 58 ++++++++++++--------
 1 file changed, 36 insertions(+), 22 deletions(-)

diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index 37c839401c6c..261680aba33c 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -975,8 +975,37 @@ static void ena_free_all_io_rx_resources(struct ena_adapter *adapter)
 		ena_free_rx_resources(adapter, i);
 }
 
-static int ena_alloc_rx_page(struct ena_ring *rx_ring,
-				    struct ena_rx_buffer *rx_info, gfp_t gfp)
+struct page *ena_alloc_map_page(struct ena_ring *rx_ring, dma_addr_t *dma)
+{
+	struct page *page;
+
+	/* This would allocate the page on the same NUMA node the executing code
+	 * is running on.
+	 */
+	page = dev_alloc_page();
+	if (!page) {
+		ena_increase_stat(&rx_ring->rx_stats.page_alloc_fail, 1,
+				  &rx_ring->syncp);
+		return ERR_PTR(-ENOSPC);
+	}
+
+	/* To enable NIC-side port-mirroring, AKA SPAN port,
+	 * we make the buffer readable from the nic as well
+	 */
+	*dma = dma_map_page(rx_ring->dev, page, 0, ENA_PAGE_SIZE,
+			    DMA_BIDIRECTIONAL);
+	if (unlikely(dma_mapping_error(rx_ring->dev, *dma))) {
+		ena_increase_stat(&rx_ring->rx_stats.dma_mapping_err, 1,
+				  &rx_ring->syncp);
+		__free_page(page);
+		return ERR_PTR(-EIO);
+	}
+
+	return page;
+}
+
+static int ena_alloc_rx_buffer(struct ena_ring *rx_ring,
+			       struct ena_rx_buffer *rx_info)
 {
 	int headroom = rx_ring->rx_headroom;
 	struct ena_com_buf *ena_buf;
@@ -991,25 +1020,11 @@ static int ena_alloc_rx_page(struct ena_ring *rx_ring,
 	if (unlikely(rx_info->page))
 		return 0;
 
-	page = alloc_page(gfp);
-	if (unlikely(!page)) {
-		ena_increase_stat(&rx_ring->rx_stats.page_alloc_fail, 1,
-				  &rx_ring->syncp);
-		return -ENOMEM;
-	}
-
-	/* To enable NIC-side port-mirroring, AKA SPAN port,
-	 * we make the buffer readable from the nic as well
-	 */
-	dma = dma_map_page(rx_ring->dev, page, 0, ENA_PAGE_SIZE,
-			   DMA_BIDIRECTIONAL);
-	if (unlikely(dma_mapping_error(rx_ring->dev, dma))) {
-		ena_increase_stat(&rx_ring->rx_stats.dma_mapping_err, 1,
-				  &rx_ring->syncp);
+	/* We handle DMA here */
+	page = ena_alloc_map_page(rx_ring, &dma);
+	if (unlikely(IS_ERR(page)))
+		return PTR_ERR(page);
 
-		__free_page(page);
-		return -EIO;
-	}
 	netif_dbg(rx_ring->adapter, rx_status, rx_ring->netdev,
 		  "Allocate page %p, rx_info %p\n", page, rx_info);
 
@@ -1065,8 +1080,7 @@ static int ena_refill_rx_bufs(struct ena_ring *rx_ring, u32 num)
 
 		rx_info = &rx_ring->rx_buffer_info[req_id];
 
-		rc = ena_alloc_rx_page(rx_ring, rx_info,
-				       GFP_ATOMIC | __GFP_COMP);
+		rc = ena_alloc_rx_buffer(rx_ring, rx_info);
 		if (unlikely(rc < 0)) {
 			netif_warn(rx_ring->adapter, rx_err, rx_ring->netdev,
 				   "Failed to allocate buffer for rx queue %d\n",
-- 
2.25.1

[Patch v1 net-next 10/10] net: ena: re-organize code to improve readability

[Shay Agroskin]

Restructure some ethtool to a switch-case blocks to make it more uniform
with other similar functions.
Also restructure variable declaration to create reversed x-mas tree.

Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
---
 drivers/net/ethernet/amazon/ena/ena_com.c     |  3 ++-
 drivers/net/ethernet/amazon/ena/ena_ethtool.c | 18 +++++++++++-------
 drivers/net/ethernet/amazon/ena/ena_netdev.c  |  2 +-
 3 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/amazon/ena/ena_com.c b/drivers/net/ethernet/amazon/ena/ena_com.c
index 764852ead1d6..ab413fc1f68e 100644
--- a/drivers/net/ethernet/amazon/ena/ena_com.c
+++ b/drivers/net/ethernet/amazon/ena/ena_com.c
@@ -1979,7 +1979,8 @@ int ena_com_get_dev_attr_feat(struct ena_com_dev *ena_dev,
 		if (rc)
 			return rc;
 
-		if (get_resp.u.max_queue_ext.version != ENA_FEATURE_MAX_QUEUE_EXT_VER)
+		if (get_resp.u.max_queue_ext.version !=
+		    ENA_FEATURE_MAX_QUEUE_EXT_VER)
 			return -EINVAL;
 
 		memcpy(&get_feat_ctx->max_queue_ext, &get_resp.u.max_queue_ext,
diff --git a/drivers/net/ethernet/amazon/ena/ena_ethtool.c b/drivers/net/ethernet/amazon/ena/ena_ethtool.c
index 2fe7ccee55b2..27dae632efcb 100644
--- a/drivers/net/ethernet/amazon/ena/ena_ethtool.c
+++ b/drivers/net/ethernet/amazon/ena/ena_ethtool.c
@@ -233,10 +233,13 @@ int ena_get_sset_count(struct net_device *netdev, int sset)
 {
 	struct ena_adapter *adapter = netdev_priv(netdev);
 
-	if (sset != ETH_SS_STATS)
-		return -EOPNOTSUPP;
+	switch (sset) {
+	case ETH_SS_STATS:
+		return ena_get_sw_stats_count(adapter) +
+		       ena_get_hw_stats_count(adapter);
+	}
 
-	return ena_get_sw_stats_count(adapter) + ena_get_hw_stats_count(adapter);
+	return -EOPNOTSUPP;
 }
 
 static void ena_queue_strings(struct ena_adapter *adapter, u8 **data)
@@ -314,10 +317,11 @@ static void ena_get_ethtool_strings(struct net_device *netdev,
 {
 	struct ena_adapter *adapter = netdev_priv(netdev);
 
-	if (sset != ETH_SS_STATS)
-		return;
-
-	ena_get_strings(adapter, data, adapter->eni_stats_supported);
+	switch (sset) {
+	case ETH_SS_STATS:
+		ena_get_strings(adapter, data, adapter->eni_stats_supported);
+		break;
+	}
 }
 
 static int ena_get_link_ksettings(struct net_device *netdev,
diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index 261680aba33c..cd6ea59c543c 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -1426,9 +1426,9 @@ static struct sk_buff *ena_rx_skb(struct ena_ring *rx_ring,
 				  u32 descs,
 				  u16 *next_to_clean)
 {
-	struct sk_buff *skb;
 	struct ena_rx_buffer *rx_info;
 	u16 len, req_id, buf = 0;
+	struct sk_buff *skb;
 	void *page_addr;
 	u32 page_offset;
 	void *data_addr;
-- 
2.25.1

Re: [Patch v1 net-next 09/10] net: ena: Use dev_alloc() in RX buffer allocation

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 2469 bytes --]

Hi Shay,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on net-next/master]

url:    https://github.com/0day-ci/linux/commits/Shay-Agroskin/Use-build_skb-and-reorganize-some-code-in-ENA/20210609-000712
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git dc8cf7550a703b8b9c94beed621c6c2474347eff
config: i386-allyesconfig (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
        # https://github.com/0day-ci/linux/commit/d37d1c673e22e4e7c24eb8bbc4c5662a7812842c
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Shay-Agroskin/Use-build_skb-and-reorganize-some-code-in-ENA/20210609-000712
        git checkout d37d1c673e22e4e7c24eb8bbc4c5662a7812842c
        # save the attached .config to linux build tree
        make W=1 ARCH=i386 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/net/ethernet/amazon/ena/ena_netdev.c:978:14: warning: no previous prototype for 'ena_alloc_map_page' [-Wmissing-prototypes]
     978 | struct page *ena_alloc_map_page(struct ena_ring *rx_ring, dma_addr_t *dma)
         |              ^~~~~~~~~~~~~~~~~~


vim +/ena_alloc_map_page +978 drivers/net/ethernet/amazon/ena/ena_netdev.c

   977	
 > 978	struct page *ena_alloc_map_page(struct ena_ring *rx_ring, dma_addr_t *dma)
   979	{
   980		struct page *page;
   981	
   982		/* This would allocate the page on the same NUMA node the executing code
   983		 * is running on.
   984		 */
   985		page = dev_alloc_page();
   986		if (!page) {
   987			ena_increase_stat(&rx_ring->rx_stats.page_alloc_fail, 1,
   988					  &rx_ring->syncp);
   989			return ERR_PTR(-ENOSPC);
   990		}
   991	
   992		/* To enable NIC-side port-mirroring, AKA SPAN port,
   993		 * we make the buffer readable from the nic as well
   994		 */
   995		*dma = dma_map_page(rx_ring->dev, page, 0, ENA_PAGE_SIZE,
   996				    DMA_BIDIRECTIONAL);
   997		if (unlikely(dma_mapping_error(rx_ring->dev, *dma))) {
   998			ena_increase_stat(&rx_ring->rx_stats.dma_mapping_err, 1,
   999					  &rx_ring->syncp);
  1000			__free_page(page);
  1001			return ERR_PTR(-EIO);
  1002		}
  1003	
  1004		return page;
  1005	}
  1006	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 65219 bytes --]

Re: [Patch v1 net-next 09/10] net: ena: Use dev_alloc() in RX buffer allocation

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 2535 bytes --]

Hi Shay,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on net-next/master]

url:    https://github.com/0day-ci/linux/commits/Shay-Agroskin/Use-build_skb-and-reorganize-some-code-in-ENA/20210609-000712
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git dc8cf7550a703b8b9c94beed621c6c2474347eff
config: i386-allyesconfig (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
        # https://github.com/0day-ci/linux/commit/d37d1c673e22e4e7c24eb8bbc4c5662a7812842c
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Shay-Agroskin/Use-build_skb-and-reorganize-some-code-in-ENA/20210609-000712
        git checkout d37d1c673e22e4e7c24eb8bbc4c5662a7812842c
        # save the attached .config to linux build tree
        make W=1 ARCH=i386 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/net/ethernet/amazon/ena/ena_netdev.c:978:14: warning: no previous prototype for 'ena_alloc_map_page' [-Wmissing-prototypes]
     978 | struct page *ena_alloc_map_page(struct ena_ring *rx_ring, dma_addr_t *dma)
         |              ^~~~~~~~~~~~~~~~~~


vim +/ena_alloc_map_page +978 drivers/net/ethernet/amazon/ena/ena_netdev.c

   977	
 > 978	struct page *ena_alloc_map_page(struct ena_ring *rx_ring, dma_addr_t *dma)
   979	{
   980		struct page *page;
   981	
   982		/* This would allocate the page on the same NUMA node the executing code
   983		 * is running on.
   984		 */
   985		page = dev_alloc_page();
   986		if (!page) {
   987			ena_increase_stat(&rx_ring->rx_stats.page_alloc_fail, 1,
   988					  &rx_ring->syncp);
   989			return ERR_PTR(-ENOSPC);
   990		}
   991	
   992		/* To enable NIC-side port-mirroring, AKA SPAN port,
   993		 * we make the buffer readable from the nic as well
   994		 */
   995		*dma = dma_map_page(rx_ring->dev, page, 0, ENA_PAGE_SIZE,
   996				    DMA_BIDIRECTIONAL);
   997		if (unlikely(dma_mapping_error(rx_ring->dev, *dma))) {
   998			ena_increase_stat(&rx_ring->rx_stats.dma_mapping_err, 1,
   999					  &rx_ring->syncp);
  1000			__free_page(page);
  1001			return ERR_PTR(-EIO);
  1002		}
  1003	
  1004		return page;
  1005	}
  1006	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 65219 bytes --]

Re: [Patch v1 net-next 00/10] Use build_skb and reorganize some code in ENA

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (refs/heads/master):

On Tue, 8 Jun 2021 19:01:08 +0300 you wrote:
> Hi all,
> this patchset introduces several changes:
> 
> - Use build_skb() on RX side.
>   This allows to ensure that the headers are in the linear part
> 
> - Batch some code into functions and remove some of the code to make it more
>   readable and less error prone
> 
> [...]

Here is the summary with links:
  - [v1,net-next,01/10] net: ena: optimize data access in fast-path code
    https://git.kernel.org/netdev/net-next/c/e4ac382ebfb4
  - [v1,net-next,02/10] net: ena: Remove unused code
    https://git.kernel.org/netdev/net-next/c/9912c72edd8c
  - [v1,net-next,03/10] net: ena: Improve error logging in driver
    https://git.kernel.org/netdev/net-next/c/091d0e85a0d4
  - [v1,net-next,04/10] net: ena: use build_skb() in RX path
    https://git.kernel.org/netdev/net-next/c/9e5269a915a8
  - [v1,net-next,05/10] net: ena: add jiffies of last napi call to stats
    https://git.kernel.org/netdev/net-next/c/0ee251cd9a63
  - [v1,net-next,06/10] net: ena: Remove module param and change message severity
    https://git.kernel.org/netdev/net-next/c/15efff76491e
  - [v1,net-next,07/10] net: ena: fix RST format in ENA documentation file
    https://git.kernel.org/netdev/net-next/c/511c537bb564
  - [v1,net-next,08/10] net: ena: aggregate doorbell common operations into a function
    https://git.kernel.org/netdev/net-next/c/9e8afb059611
  - [v1,net-next,09/10] net: ena: Use dev_alloc() in RX buffer allocation
    https://git.kernel.org/netdev/net-next/c/947c54c395cb
  - [v1,net-next,10/10] net: ena: re-organize code to improve readability
    https://git.kernel.org/netdev/net-next/c/a01f2cd0ccf4

You are awesome, thank you!
--
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