[PATCH net-next 00/11][pull request] 40GbE Intel Wired LAN Driver Updates 2021-02-12

[PATCH net-next 00/11][pull request] 40GbE Intel Wired LAN Driver Updates 2021-02-12

[Tony Nguyen]

This series contains updates to i40e, ice, and ixgbe drivers.

Maciej does cleanups on the following drivers.
For i40e, removes redundant check for XDP prog, cleans up no longer
relevant information, and removes an unused function argument.
For ice, removes local variable use, instead returning values directly.
Moves skb pointer from buffer to ring and removes an unneeded check for
xdp_prog in zero copy path. Also removes a redundant MTU check when
changing it.
For i40e, ice, and ixgbe, stores the rx_offset in the Rx ring as
the value is constant so there's no need for continual calls.

Bjorn folds a decrement into a while statement.

The following are changes since commit 3c5a2fd042d0bfac71a2dfb99515723d318df47b:
  tcp: Sanitize CMSG flags and reserved args in tcp_zerocopy_receive.
and are available in the git repository at:
  git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/next-queue 40GbE

Björn Töpel (1):
  i40e: Simplify the do-while allocation loop

Maciej Fijalkowski (10):
  i40e: drop redundant check when setting xdp prog
  i40e: drop misleading function comments
  i40e: adjust i40e_is_non_eop
  ice: simplify ice_run_xdp
  ice: move skb pointer from rx_buf to rx_ring
  ice: remove redundant checks in ice_change_mtu
  ice: skip NULL check against XDP prog in ZC path
  i40e: store the result of i40e_rx_offset() onto i40e_ring
  ice: store the result of ice_rx_offset() onto ice_ring
  ixgbe: store the result of ixgbe_rx_offset() onto ixgbe_ring

 drivers/net/ethernet/intel/i40e/i40e_main.c   |  3 -
 drivers/net/ethernet/intel/i40e/i40e_txrx.c   | 91 ++++++-------------
 drivers/net/ethernet/intel/i40e/i40e_txrx.h   |  1 +
 drivers/net/ethernet/intel/i40e/i40e_xsk.c    |  4 +-
 drivers/net/ethernet/intel/ice/ice_main.c     |  9 --
 drivers/net/ethernet/intel/ice/ice_txrx.c     | 88 ++++++++----------
 drivers/net/ethernet/intel/ice/ice_txrx.h     |  3 +-
 drivers/net/ethernet/intel/ice/ice_xsk.c      |  7 +-
 drivers/net/ethernet/intel/ixgbe/ixgbe.h      |  1 +
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 15 +--
 10 files changed, 86 insertions(+), 136 deletions(-)

-- 
2.26.2

[PATCH net-next 01/11] i40e: drop redundant check when setting xdp prog

[Tony Nguyen]

From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>

Net core handles the case where netdev has no xdp prog attached and
current prog is NULL. Therefore, remove such check within
i40e_xdp_setup.

Reviewed-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Kiran Bhandare <kiranx.bhandare@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_main.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 63e19d2e3301..8bb8eb65add9 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -12947,9 +12947,6 @@ static int i40e_xdp_setup(struct i40e_vsi *vsi, struct bpf_prog *prog,
 		return -EINVAL;
 	}
 
-	if (!i40e_enabled_xdp_vsi(vsi) && !prog)
-		return 0;
-
 	/* When turning XDP on->off/off->on we reset and rebuild the rings. */
 	need_reset = (i40e_enabled_xdp_vsi(vsi) != !!prog);
 
-- 
2.26.2

[PATCH net-next 02/11] i40e: drop misleading function comments

[Tony Nguyen]

From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>

i40e_cleanup_headers has a statement about check against skb being
linear or not which is not relevant anymore, so let's remove it.

Same case for i40e_can_reuse_rx_page, it references things that are not
present there anymore.

Reviewed-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_txrx.c | 33 ++++-----------------
 1 file changed, 6 insertions(+), 27 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 3d24c6032616..5f6aa13e85ca 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -1963,9 +1963,6 @@ void i40e_process_skb_fields(struct i40e_ring *rx_ring,
  * @skb: pointer to current skb being fixed
  * @rx_desc: pointer to the EOP Rx descriptor
  *
- * Also address the case where we are pulling data in on pages only
- * and as such no data is present in the skb header.
- *
  * In addition if skb is not at least 60 bytes we need to pad it so that
  * it is large enough to qualify as a valid Ethernet frame.
  *
@@ -1998,33 +1995,15 @@ static bool i40e_cleanup_headers(struct i40e_ring *rx_ring, struct sk_buff *skb,
 }
 
 /**
- * i40e_can_reuse_rx_page - Determine if this page can be reused by
- * the adapter for another receive
- *
+ * i40e_can_reuse_rx_page - Determine if page can be reused for another Rx
  * @rx_buffer: buffer containing the page
  * @rx_buffer_pgcnt: buffer page refcount pre xdp_do_redirect() call
  *
- * If page is reusable, rx_buffer->page_offset is adjusted to point to
- * an unused region in the page.
- *
- * For small pages, @truesize will be a constant value, half the size
- * of the memory at page.  We'll attempt to alternate between high and
- * low halves of the page, with one half ready for use by the hardware
- * and the other half being consumed by the stack.  We use the page
- * ref count to determine whether the stack has finished consuming the
- * portion of this page that was passed up with a previous packet.  If
- * the page ref count is >1, we'll assume the "other" half page is
- * still busy, and this page cannot be reused.
- *
- * For larger pages, @truesize will be the actual space used by the
- * received packet (adjusted upward to an even multiple of the cache
- * line size).  This will advance through the page by the amount
- * actually consumed by the received packets while there is still
- * space for a buffer.  Each region of larger pages will be used at
- * most once, after which the page will not be reused.
- *
- * In either case, if the page is reusable its refcount is increased.
- **/
+ * If page is reusable, we have a green light for calling i40e_reuse_rx_page,
+ * which will assign the current buffer to the buffer that next_to_alloc is
+ * pointing to; otherwise, the DMA mapping needs to be destroyed and
+ * page freed
+ */
 static bool i40e_can_reuse_rx_page(struct i40e_rx_buffer *rx_buffer,
 				   int rx_buffer_pgcnt)
 {
-- 
2.26.2

[PATCH net-next 03/11] i40e: adjust i40e_is_non_eop

[Tony Nguyen]

From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>

i40e_is_non_eop had a leftover comment and unused skb argument which was
used for placing the skb onto rx_buf in case when current buffer was
non-eop one. This is not relevant anymore as commit e72e56597ba1
("i40e/i40evf: Moves skb from i40e_rx_buffer to i40e_ring") pulled the
non-complete skb handling out of rx_bufs up to rx_ring.  Therefore,
let's adjust the function arguments that i40e_is_non_eop takes.

Furthermore, since there is already a function responsible for bumping
the ntc, make use of that and drop that logic from i40e_is_non_eop so
that the scope of this function is limited to what the name actually
states.

Reviewed-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_txrx.c | 23 ++++++---------------
 1 file changed, 6 insertions(+), 17 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 5f6aa13e85ca..79ca608ee152 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -2271,25 +2271,13 @@ static void i40e_put_rx_buffer(struct i40e_ring *rx_ring,
  * i40e_is_non_eop - process handling of non-EOP buffers
  * @rx_ring: Rx ring being processed
  * @rx_desc: Rx descriptor for current buffer
- * @skb: Current socket buffer containing buffer in progress
  *
- * This function updates next to clean.  If the buffer is an EOP buffer
- * this function exits returning false, otherwise it will place the
- * sk_buff in the next buffer to be chained and return true indicating
- * that this is in fact a non-EOP buffer.
- **/
+ * If the buffer is an EOP buffer, this function exits returning false,
+ * otherwise return true indicating that this is in fact a non-EOP buffer.
+ */
 static bool i40e_is_non_eop(struct i40e_ring *rx_ring,
-			    union i40e_rx_desc *rx_desc,
-			    struct sk_buff *skb)
+			    union i40e_rx_desc *rx_desc)
 {
-	u32 ntc = rx_ring->next_to_clean + 1;
-
-	/* fetch, update, and store next to clean */
-	ntc = (ntc < rx_ring->count) ? ntc : 0;
-	rx_ring->next_to_clean = ntc;
-
-	prefetch(I40E_RX_DESC(rx_ring, ntc));
-
 	/* if we are the last buffer then there is nothing else to do */
 #define I40E_RXD_EOF BIT(I40E_RX_DESC_STATUS_EOF_SHIFT)
 	if (likely(i40e_test_staterr(rx_desc, I40E_RXD_EOF)))
@@ -2568,7 +2556,8 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
 		i40e_put_rx_buffer(rx_ring, rx_buffer, rx_buffer_pgcnt);
 		cleaned_count++;
 
-		if (i40e_is_non_eop(rx_ring, rx_desc, skb))
+		i40e_inc_ntc(rx_ring);
+		if (i40e_is_non_eop(rx_ring, rx_desc))
 			continue;
 
 		if (i40e_cleanup_headers(rx_ring, skb, rx_desc)) {
-- 
2.26.2

[PATCH net-next 04/11] ice: simplify ice_run_xdp

[Tony Nguyen]

From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>

There's no need for 'result' variable, we can directly return the
internal status based on action returned by xdp prog.

Reviewed-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Kiran Bhandare <kiranx.bhandare@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_txrx.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c
index 580419813bb2..47d8100159c5 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx.c
+++ b/drivers/net/ethernet/intel/ice/ice_txrx.c
@@ -537,22 +537,20 @@ static int
 ice_run_xdp(struct ice_ring *rx_ring, struct xdp_buff *xdp,
 	    struct bpf_prog *xdp_prog)
 {
-	int err, result = ICE_XDP_PASS;
 	struct ice_ring *xdp_ring;
+	int err;
 	u32 act;
 
 	act = bpf_prog_run_xdp(xdp_prog, xdp);
 	switch (act) {
 	case XDP_PASS:
-		break;
+		return ICE_XDP_PASS;
 	case XDP_TX:
 		xdp_ring = rx_ring->vsi->xdp_rings[smp_processor_id()];
-		result = ice_xmit_xdp_buff(xdp, xdp_ring);
-		break;
+		return ice_xmit_xdp_buff(xdp, xdp_ring);
 	case XDP_REDIRECT:
 		err = xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog);
-		result = !err ? ICE_XDP_REDIR : ICE_XDP_CONSUMED;
-		break;
+		return !err ? ICE_XDP_REDIR : ICE_XDP_CONSUMED;
 	default:
 		bpf_warn_invalid_xdp_action(act);
 		fallthrough;
@@ -560,11 +558,8 @@ ice_run_xdp(struct ice_ring *rx_ring, struct xdp_buff *xdp,
 		trace_xdp_exception(rx_ring->netdev, xdp_prog, act);
 		fallthrough;
 	case XDP_DROP:
-		result = ICE_XDP_CONSUMED;
-		break;
+		return ICE_XDP_CONSUMED;
 	}
-
-	return result;
 }
 
 /**
-- 
2.26.2

[PATCH net-next 05/11] ice: move skb pointer from rx_buf to rx_ring

[Tony Nguyen]

From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>

Similar thing has been done in i40e, as there is no real need for having
the sk_buff pointer in each rx_buf. Non-eop frames can be simply handled
on that pointer moved upwards to rx_ring.

Reviewed-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_txrx.c | 30 ++++++++++-------------
 drivers/net/ethernet/intel/ice/ice_txrx.h |  2 +-
 2 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c
index 47d8100159c5..d92ddcdeaa4d 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx.c
+++ b/drivers/net/ethernet/intel/ice/ice_txrx.c
@@ -375,6 +375,11 @@ void ice_clean_rx_ring(struct ice_ring *rx_ring)
 	if (!rx_ring->rx_buf)
 		return;
 
+	if (rx_ring->skb) {
+		dev_kfree_skb(rx_ring->skb);
+		rx_ring->skb = NULL;
+	}
+
 	if (rx_ring->xsk_pool) {
 		ice_xsk_clean_rx_ring(rx_ring);
 		goto rx_skip_free;
@@ -384,10 +389,6 @@ void ice_clean_rx_ring(struct ice_ring *rx_ring)
 	for (i = 0; i < rx_ring->count; i++) {
 		struct ice_rx_buf *rx_buf = &rx_ring->rx_buf[i];
 
-		if (rx_buf->skb) {
-			dev_kfree_skb(rx_buf->skb);
-			rx_buf->skb = NULL;
-		}
 		if (!rx_buf->page)
 			continue;
 
@@ -850,7 +851,6 @@ ice_reuse_rx_page(struct ice_ring *rx_ring, struct ice_rx_buf *old_buf)
 /**
  * ice_get_rx_buf - Fetch Rx buffer and synchronize data for use
  * @rx_ring: Rx descriptor ring to transact packets on
- * @skb: skb to be used
  * @size: size of buffer to add to skb
  * @rx_buf_pgcnt: rx_buf page refcount
  *
@@ -858,8 +858,8 @@ ice_reuse_rx_page(struct ice_ring *rx_ring, struct ice_rx_buf *old_buf)
  * for use by the CPU.
  */
 static struct ice_rx_buf *
-ice_get_rx_buf(struct ice_ring *rx_ring, struct sk_buff **skb,
-	       const unsigned int size, int *rx_buf_pgcnt)
+ice_get_rx_buf(struct ice_ring *rx_ring, const unsigned int size,
+	       int *rx_buf_pgcnt)
 {
 	struct ice_rx_buf *rx_buf;
 
@@ -871,7 +871,6 @@ ice_get_rx_buf(struct ice_ring *rx_ring, struct sk_buff **skb,
 		0;
 #endif
 	prefetchw(rx_buf->page);
-	*skb = rx_buf->skb;
 
 	if (!size)
 		return rx_buf;
@@ -1033,29 +1032,24 @@ ice_put_rx_buf(struct ice_ring *rx_ring, struct ice_rx_buf *rx_buf,
 
 	/* clear contents of buffer_info */
 	rx_buf->page = NULL;
-	rx_buf->skb = NULL;
 }
 
 /**
  * ice_is_non_eop - process handling of non-EOP buffers
  * @rx_ring: Rx ring being processed
  * @rx_desc: Rx descriptor for current buffer
- * @skb: Current socket buffer containing buffer in progress
  *
  * If the buffer is an EOP buffer, this function exits returning false,
  * otherwise return true indicating that this is in fact a non-EOP buffer.
  */
 static bool
-ice_is_non_eop(struct ice_ring *rx_ring, union ice_32b_rx_flex_desc *rx_desc,
-	       struct sk_buff *skb)
+ice_is_non_eop(struct ice_ring *rx_ring, union ice_32b_rx_flex_desc *rx_desc)
 {
 	/* if we are the last buffer then there is nothing else to do */
 #define ICE_RXD_EOF BIT(ICE_RX_FLEX_DESC_STATUS0_EOF_S)
 	if (likely(ice_test_staterr(rx_desc, ICE_RXD_EOF)))
 		return false;
 
-	/* place skb in next buffer to be received */
-	rx_ring->rx_buf[rx_ring->next_to_clean].skb = skb;
 	rx_ring->rx_stats.non_eop_descs++;
 
 	return true;
@@ -1078,6 +1072,7 @@ int ice_clean_rx_irq(struct ice_ring *rx_ring, int budget)
 	unsigned int total_rx_bytes = 0, total_rx_pkts = 0, frame_sz = 0;
 	u16 cleaned_count = ICE_DESC_UNUSED(rx_ring);
 	unsigned int xdp_res, xdp_xmit = 0;
+	struct sk_buff *skb = rx_ring->skb;
 	struct bpf_prog *xdp_prog = NULL;
 	struct xdp_buff xdp;
 	bool failure;
@@ -1094,7 +1089,6 @@ int ice_clean_rx_irq(struct ice_ring *rx_ring, int budget)
 		union ice_32b_rx_flex_desc *rx_desc;
 		struct ice_rx_buf *rx_buf;
 		unsigned char *hard_start;
-		struct sk_buff *skb;
 		unsigned int size;
 		u16 stat_err_bits;
 		int rx_buf_pgcnt;
@@ -1129,7 +1123,7 @@ int ice_clean_rx_irq(struct ice_ring *rx_ring, int budget)
 			ICE_RX_FLX_DESC_PKT_LEN_M;
 
 		/* retrieve a buffer from the ring */
-		rx_buf = ice_get_rx_buf(rx_ring, &skb, size, &rx_buf_pgcnt);
+		rx_buf = ice_get_rx_buf(rx_ring, size, &rx_buf_pgcnt);
 
 		if (!size) {
 			xdp.data = NULL;
@@ -1191,7 +1185,7 @@ int ice_clean_rx_irq(struct ice_ring *rx_ring, int budget)
 		cleaned_count++;
 
 		/* skip if it is NOP desc */
-		if (ice_is_non_eop(rx_ring, rx_desc, skb))
+		if (ice_is_non_eop(rx_ring, rx_desc))
 			continue;
 
 		stat_err_bits = BIT(ICE_RX_FLEX_DESC_STATUS0_RXE_S);
@@ -1221,6 +1215,7 @@ int ice_clean_rx_irq(struct ice_ring *rx_ring, int budget)
 
 		/* send completed skb up the stack */
 		ice_receive_skb(rx_ring, skb, vlan_tag);
+		skb = NULL;
 
 		/* update budget accounting */
 		total_rx_pkts++;
@@ -1231,6 +1226,7 @@ int ice_clean_rx_irq(struct ice_ring *rx_ring, int budget)
 
 	if (xdp_prog)
 		ice_finalize_xdp_rx(rx_ring, xdp_xmit);
+	rx_ring->skb = skb;
 
 	ice_update_rx_ring_stats(rx_ring, total_rx_pkts, total_rx_bytes);
 
diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.h b/drivers/net/ethernet/intel/ice/ice_txrx.h
index db56a0c8bfe1..1425f5e68611 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx.h
+++ b/drivers/net/ethernet/intel/ice/ice_txrx.h
@@ -165,7 +165,6 @@ struct ice_tx_offload_params {
 struct ice_rx_buf {
 	union {
 		struct {
-			struct sk_buff *skb;
 			dma_addr_t dma;
 			struct page *page;
 			unsigned int page_offset;
@@ -297,6 +296,7 @@ struct ice_ring {
 	struct xsk_buff_pool *xsk_pool;
 	/* CL3 - 3rd cacheline starts here */
 	struct xdp_rxq_info xdp_rxq;
+	struct sk_buff *skb;
 	/* CLX - the below items are only accessed infrequently and should be
 	 * in their own cache line if possible
 	 */
-- 
2.26.2

[PATCH net-next 06/11] ice: remove redundant checks in ice_change_mtu

[Tony Nguyen]

From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>

dev_validate_mtu checks that mtu value specified by user is not less
than min mtu and not greater than max allowed mtu. It is being done
before calling the ndo_change_mtu exposed by driver, so remove these
redundant checks in ice_change_mtu.

Reviewed-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_main.c | 9 ---------
 1 file changed, 9 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index 813ec6b8ac23..2c23c8f468a5 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -6154,15 +6154,6 @@ static int ice_change_mtu(struct net_device *netdev, int new_mtu)
 		}
 	}
 
-	if (new_mtu < (int)netdev->min_mtu) {
-		netdev_err(netdev, "new MTU invalid. min_mtu is %d\n",
-			   netdev->min_mtu);
-		return -EINVAL;
-	} else if (new_mtu > (int)netdev->max_mtu) {
-		netdev_err(netdev, "new MTU invalid. max_mtu is %d\n",
-			   netdev->min_mtu);
-		return -EINVAL;
-	}
 	/* if a reset is in progress, wait for some time for it to complete */
 	do {
 		if (ice_is_reset_in_progress(pf->state)) {
-- 
2.26.2

[PATCH net-next 07/11] ice: skip NULL check against XDP prog in ZC path

[Tony Nguyen]

From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>

Whole zero-copy variant of clean Rx IRQ is executed when xsk_pool is
attached to rx_ring and it can happen only when XDP program is present
on interface. Therefore it is safe to assume that program is always
!NULL and there is no need for checking it in ice_run_xdp_zc.

Reviewed-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Kiran Bhandare <kiranx.bhandare@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_xsk.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c
index 875fa0cbef56..83f3c9574ed1 100644
--- a/drivers/net/ethernet/intel/ice/ice_xsk.c
+++ b/drivers/net/ethernet/intel/ice/ice_xsk.c
@@ -467,11 +467,10 @@ ice_run_xdp_zc(struct ice_ring *rx_ring, struct xdp_buff *xdp)
 	u32 act;
 
 	rcu_read_lock();
+	/* ZC patch is enabled only when XDP program is set,
+	 * so here it can not be NULL
+	 */
 	xdp_prog = READ_ONCE(rx_ring->xdp_prog);
-	if (!xdp_prog) {
-		rcu_read_unlock();
-		return ICE_XDP_PASS;
-	}
 
 	act = bpf_prog_run_xdp(xdp_prog, xdp);
 	switch (act) {
-- 
2.26.2

[PATCH net-next 08/11] i40e: Simplify the do-while allocation loop

[Tony Nguyen]

From: Björn Töpel <bjorn.topel@intel.com>

Fold the count decrement into the while-statement.

Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Tested-by: Kiran Bhandare <kiranx.bhandare@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_xsk.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index 470b8600adb1..4f11f7bf75d1 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -215,9 +215,7 @@ bool i40e_alloc_rx_buffers_zc(struct i40e_ring *rx_ring, u16 count)
 			bi = i40e_rx_bi(rx_ring, 0);
 			ntu = 0;
 		}
-
-		count--;
-	} while (count);
+	} while (--count);
 
 no_buffers:
 	if (rx_ring->next_to_use != ntu) {
-- 
2.26.2

[PATCH net-next 09/11] i40e: store the result of i40e_rx_offset() onto i40e_ring

[Tony Nguyen]

From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>

Output of i40e_rx_offset() is based on ethtool's priv flag setting,
which when changed, causes PF reset (disables napi, frees irqs, loads
different Rx mem model, etc.). This means that within napi its result is
constant and there is no reason to call it per each processed frame.

Add new 'rx_offset' field to i40e_ring that is meant to hold the
i40e_rx_offset() result and use it within i40e_clean_rx_irq().
Furthermore, use it within i40e_alloc_mapped_page().

Last but not least, un-inline the function of interest so that compiler
makes the decision about inlining as it lives in .c file.

Reviewed-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_txrx.c | 35 +++++++++++----------
 drivers/net/ethernet/intel/i40e/i40e_txrx.h |  1 +
 2 files changed, 19 insertions(+), 17 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 79ca608ee152..f6f1af94cca0 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -1569,6 +1569,17 @@ void i40e_free_rx_resources(struct i40e_ring *rx_ring)
 	}
 }
 
+/**
+ * i40e_rx_offset - Return expected offset into page to access data
+ * @rx_ring: Ring we are requesting offset of
+ *
+ * Returns the offset value for ring into the data buffer.
+ */
+static unsigned int i40e_rx_offset(struct i40e_ring *rx_ring)
+{
+	return ring_uses_build_skb(rx_ring) ? I40E_SKB_PAD : 0;
+}
+
 /**
  * i40e_setup_rx_descriptors - Allocate Rx descriptors
  * @rx_ring: Rx descriptor ring (for a specific queue) to setup
@@ -1597,6 +1608,7 @@ int i40e_setup_rx_descriptors(struct i40e_ring *rx_ring)
 	rx_ring->next_to_alloc = 0;
 	rx_ring->next_to_clean = 0;
 	rx_ring->next_to_use = 0;
+	rx_ring->rx_offset = i40e_rx_offset(rx_ring);
 
 	/* XDP RX-queue info only needed for RX rings exposed to XDP */
 	if (rx_ring->vsi->type == I40E_VSI_MAIN) {
@@ -1632,17 +1644,6 @@ void i40e_release_rx_desc(struct i40e_ring *rx_ring, u32 val)
 	writel(val, rx_ring->tail);
 }
 
-/**
- * i40e_rx_offset - Return expected offset into page to access data
- * @rx_ring: Ring we are requesting offset of
- *
- * Returns the offset value for ring into the data buffer.
- */
-static inline unsigned int i40e_rx_offset(struct i40e_ring *rx_ring)
-{
-	return ring_uses_build_skb(rx_ring) ? I40E_SKB_PAD : 0;
-}
-
 static unsigned int i40e_rx_frame_truesize(struct i40e_ring *rx_ring,
 					   unsigned int size)
 {
@@ -1651,8 +1652,8 @@ static unsigned int i40e_rx_frame_truesize(struct i40e_ring *rx_ring,
 #if (PAGE_SIZE < 8192)
 	truesize = i40e_rx_pg_size(rx_ring) / 2; /* Must be power-of-2 */
 #else
-	truesize = i40e_rx_offset(rx_ring) ?
-		SKB_DATA_ALIGN(size + i40e_rx_offset(rx_ring)) +
+	truesize = rx_ring->rx_offset ?
+		SKB_DATA_ALIGN(size + rx_ring->rx_offset) +
 		SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) :
 		SKB_DATA_ALIGN(size);
 #endif
@@ -1703,7 +1704,7 @@ static bool i40e_alloc_mapped_page(struct i40e_ring *rx_ring,
 
 	bi->dma = dma;
 	bi->page = page;
-	bi->page_offset = i40e_rx_offset(rx_ring);
+	bi->page_offset = rx_ring->rx_offset;
 	page_ref_add(page, USHRT_MAX - 1);
 	bi->pagecnt_bias = USHRT_MAX;
 
@@ -2057,7 +2058,7 @@ static void i40e_add_rx_frag(struct i40e_ring *rx_ring,
 #if (PAGE_SIZE < 8192)
 	unsigned int truesize = i40e_rx_pg_size(rx_ring) / 2;
 #else
-	unsigned int truesize = SKB_DATA_ALIGN(size + i40e_rx_offset(rx_ring));
+	unsigned int truesize = SKB_DATA_ALIGN(size + rx_ring->rx_offset);
 #endif
 
 	skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_buffer->page,
@@ -2453,8 +2454,9 @@ static void i40e_inc_ntc(struct i40e_ring *rx_ring)
 static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
 {
 	unsigned int total_rx_bytes = 0, total_rx_packets = 0, frame_sz = 0;
-	struct sk_buff *skb = rx_ring->skb;
 	u16 cleaned_count = I40E_DESC_UNUSED(rx_ring);
+	unsigned int offset = rx_ring->rx_offset;
+	struct sk_buff *skb = rx_ring->skb;
 	unsigned int xdp_xmit = 0;
 	bool failure = false;
 	struct xdp_buff xdp;
@@ -2514,7 +2516,6 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
 
 		/* retrieve a buffer from the ring */
 		if (!skb) {
-			unsigned int offset = i40e_rx_offset(rx_ring);
 			unsigned char *hard_start;
 
 			hard_start = page_address(rx_buffer->page) +
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.h b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
index 5f531b195959..86fed05b4f19 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
@@ -387,6 +387,7 @@ struct i40e_ring {
 					 */
 
 	struct i40e_channel *ch;
+	u16 rx_offset;
 	struct xdp_rxq_info xdp_rxq;
 	struct xsk_buff_pool *xsk_pool;
 	struct xdp_desc *xsk_descs;      /* For storing descriptors in the AF_XDP ZC path */
-- 
2.26.2

[PATCH net-next 10/11] ice: store the result of ice_rx_offset() onto ice_ring

[Tony Nguyen]

From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>

Output of ice_rx_offset() is based on ethtool's priv flag setting, which
when changed, causes PF reset (disables napi, frees irqs, loads
different Rx mem model, etc.). This means that within napi its result is
constant and there is no reason to call it per each processed frame.

Add new 'rx_offset' field to ice_ring that is meant to hold the
ice_rx_offset() result and use it within ice_clean_rx_irq().
Furthermore, use it within ice_alloc_mapped_page().

Reviewed-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_txrx.c | 43 ++++++++++++-----------
 drivers/net/ethernet/intel/ice/ice_txrx.h |  1 +
 2 files changed, 23 insertions(+), 21 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c
index d92ddcdeaa4d..b7dc25da1202 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx.c
+++ b/drivers/net/ethernet/intel/ice/ice_txrx.c
@@ -443,6 +443,22 @@ void ice_free_rx_ring(struct ice_ring *rx_ring)
 	}
 }
 
+/**
+ * ice_rx_offset - Return expected offset into page to access data
+ * @rx_ring: Ring we are requesting offset of
+ *
+ * Returns the offset value for ring into the data buffer.
+ */
+static unsigned int ice_rx_offset(struct ice_ring *rx_ring)
+{
+	if (ice_ring_uses_build_skb(rx_ring))
+		return ICE_SKB_PAD;
+	else if (ice_is_xdp_ena_vsi(rx_ring->vsi))
+		return XDP_PACKET_HEADROOM;
+
+	return 0;
+}
+
 /**
  * ice_setup_rx_ring - Allocate the Rx descriptors
  * @rx_ring: the Rx ring to set up
@@ -477,6 +493,7 @@ int ice_setup_rx_ring(struct ice_ring *rx_ring)
 
 	rx_ring->next_to_use = 0;
 	rx_ring->next_to_clean = 0;
+	rx_ring->rx_offset = ice_rx_offset(rx_ring);
 
 	if (ice_is_xdp_ena_vsi(rx_ring->vsi))
 		WRITE_ONCE(rx_ring->xdp_prog, rx_ring->vsi->xdp_prog);
@@ -494,22 +511,6 @@ int ice_setup_rx_ring(struct ice_ring *rx_ring)
 	return -ENOMEM;
 }
 
-/**
- * ice_rx_offset - Return expected offset into page to access data
- * @rx_ring: Ring we are requesting offset of
- *
- * Returns the offset value for ring into the data buffer.
- */
-static unsigned int ice_rx_offset(struct ice_ring *rx_ring)
-{
-	if (ice_ring_uses_build_skb(rx_ring))
-		return ICE_SKB_PAD;
-	else if (ice_is_xdp_ena_vsi(rx_ring->vsi))
-		return XDP_PACKET_HEADROOM;
-
-	return 0;
-}
-
 static unsigned int
 ice_rx_frame_truesize(struct ice_ring *rx_ring, unsigned int __maybe_unused size)
 {
@@ -518,8 +519,8 @@ ice_rx_frame_truesize(struct ice_ring *rx_ring, unsigned int __maybe_unused size
 #if (PAGE_SIZE < 8192)
 	truesize = ice_rx_pg_size(rx_ring) / 2; /* Must be power-of-2 */
 #else
-	truesize = ice_rx_offset(rx_ring) ?
-		SKB_DATA_ALIGN(ice_rx_offset(rx_ring) + size) +
+	truesize = rx_ring->rx_offset ?
+		SKB_DATA_ALIGN(rx_ring->rx_offset + size) +
 		SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) :
 		SKB_DATA_ALIGN(size);
 #endif
@@ -652,7 +653,7 @@ ice_alloc_mapped_page(struct ice_ring *rx_ring, struct ice_rx_buf *bi)
 
 	bi->dma = dma;
 	bi->page = page;
-	bi->page_offset = ice_rx_offset(rx_ring);
+	bi->page_offset = rx_ring->rx_offset;
 	page_ref_add(page, USHRT_MAX - 1);
 	bi->pagecnt_bias = USHRT_MAX;
 
@@ -805,7 +806,7 @@ ice_add_rx_frag(struct ice_ring *rx_ring, struct ice_rx_buf *rx_buf,
 		struct sk_buff *skb, unsigned int size)
 {
 #if (PAGE_SIZE >= 8192)
-	unsigned int truesize = SKB_DATA_ALIGN(size + ice_rx_offset(rx_ring));
+	unsigned int truesize = SKB_DATA_ALIGN(size + rx_ring->rx_offset);
 #else
 	unsigned int truesize = ice_rx_pg_size(rx_ring) / 2;
 #endif
@@ -1071,6 +1072,7 @@ int ice_clean_rx_irq(struct ice_ring *rx_ring, int budget)
 {
 	unsigned int total_rx_bytes = 0, total_rx_pkts = 0, frame_sz = 0;
 	u16 cleaned_count = ICE_DESC_UNUSED(rx_ring);
+	unsigned int offset = rx_ring->rx_offset;
 	unsigned int xdp_res, xdp_xmit = 0;
 	struct sk_buff *skb = rx_ring->skb;
 	struct bpf_prog *xdp_prog = NULL;
@@ -1085,7 +1087,6 @@ int ice_clean_rx_irq(struct ice_ring *rx_ring, int budget)
 
 	/* start the loop to process Rx packets bounded by 'budget' */
 	while (likely(total_rx_pkts < (unsigned int)budget)) {
-		unsigned int offset = ice_rx_offset(rx_ring);
 		union ice_32b_rx_flex_desc *rx_desc;
 		struct ice_rx_buf *rx_buf;
 		unsigned char *hard_start;
diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.h b/drivers/net/ethernet/intel/ice/ice_txrx.h
index 1425f5e68611..5dab77504fa5 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx.h
+++ b/drivers/net/ethernet/intel/ice/ice_txrx.h
@@ -294,6 +294,7 @@ struct ice_ring {
 	struct rcu_head rcu;		/* to avoid race on free */
 	struct bpf_prog *xdp_prog;
 	struct xsk_buff_pool *xsk_pool;
+	u16 rx_offset;
 	/* CL3 - 3rd cacheline starts here */
 	struct xdp_rxq_info xdp_rxq;
 	struct sk_buff *skb;
-- 
2.26.2

[PATCH net-next 11/11] ixgbe: store the result of ixgbe_rx_offset() onto ixgbe_ring

[Tony Nguyen]

From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>

Output of ixgbe_rx_offset() is based on ethtool's priv flag setting, which
when changed, causes PF reset (disables napi, frees irqs, loads
different Rx mem model, etc.). This means that within napi its result is
constant and there is no reason to call it per each processed frame.

Add new 'rx_offset' field to ixgbe_ring that is meant to hold the
ixgbe_rx_offset() result and use it within ixgbe_clean_rx_irq().
Furthermore, use it within ixgbe_alloc_mapped_page().

Last but not least, un-inline the function of interest as it lives in .c
file so let compiler do the decision about the inlining.

Reviewed-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe.h      |  1 +
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 15 ++++++++-------
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe.h b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
index de0fc6ecf491..a604552fa634 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
@@ -349,6 +349,7 @@ struct ixgbe_ring {
 		struct ixgbe_tx_queue_stats tx_stats;
 		struct ixgbe_rx_queue_stats rx_stats;
 	};
+	u16 rx_offset;
 	struct xdp_rxq_info xdp_rxq;
 	struct xsk_buff_pool *xsk_pool;
 	u16 ring_idx;		/* {rx,tx,xdp}_ring back reference idx */
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 237e09342f28..fae84202d870 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -1520,7 +1520,7 @@ static inline void ixgbe_rx_checksum(struct ixgbe_ring *ring,
 	}
 }
 
-static inline unsigned int ixgbe_rx_offset(struct ixgbe_ring *rx_ring)
+static unsigned int ixgbe_rx_offset(struct ixgbe_ring *rx_ring)
 {
 	return ring_uses_build_skb(rx_ring) ? IXGBE_SKB_PAD : 0;
 }
@@ -1561,7 +1561,7 @@ static bool ixgbe_alloc_mapped_page(struct ixgbe_ring *rx_ring,
 
 	bi->dma = dma;
 	bi->page = page;
-	bi->page_offset = ixgbe_rx_offset(rx_ring);
+	bi->page_offset = rx_ring->rx_offset;
 	page_ref_add(page, USHRT_MAX - 1);
 	bi->pagecnt_bias = USHRT_MAX;
 	rx_ring->rx_stats.alloc_rx_page++;
@@ -2001,8 +2001,8 @@ static void ixgbe_add_rx_frag(struct ixgbe_ring *rx_ring,
 #if (PAGE_SIZE < 8192)
 	unsigned int truesize = ixgbe_rx_pg_size(rx_ring) / 2;
 #else
-	unsigned int truesize = ring_uses_build_skb(rx_ring) ?
-				SKB_DATA_ALIGN(IXGBE_SKB_PAD + size) :
+	unsigned int truesize = rx_ring->rx_offset ?
+				SKB_DATA_ALIGN(rx_ring->rx_offset + size) :
 				SKB_DATA_ALIGN(size);
 #endif
 	skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_buffer->page,
@@ -2249,8 +2249,8 @@ static unsigned int ixgbe_rx_frame_truesize(struct ixgbe_ring *rx_ring,
 #if (PAGE_SIZE < 8192)
 	truesize = ixgbe_rx_pg_size(rx_ring) / 2; /* Must be power-of-2 */
 #else
-	truesize = ring_uses_build_skb(rx_ring) ?
-		SKB_DATA_ALIGN(IXGBE_SKB_PAD + size) +
+	truesize = rx_ring->rx_offset ?
+		SKB_DATA_ALIGN(rx_ring->rx_offset + size) +
 		SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) :
 		SKB_DATA_ALIGN(size);
 #endif
@@ -2293,6 +2293,7 @@ static int ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
 	unsigned int mss = 0;
 #endif /* IXGBE_FCOE */
 	u16 cleaned_count = ixgbe_desc_unused(rx_ring);
+	unsigned int offset = rx_ring->rx_offset;
 	unsigned int xdp_xmit = 0;
 	struct xdp_buff xdp;
 
@@ -2330,7 +2331,6 @@ static int ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
 
 		/* retrieve a buffer from the ring */
 		if (!skb) {
-			unsigned int offset = ixgbe_rx_offset(rx_ring);
 			unsigned char *hard_start;
 
 			hard_start = page_address(rx_buffer->page) +
@@ -6578,6 +6578,7 @@ int ixgbe_setup_rx_resources(struct ixgbe_adapter *adapter,
 
 	rx_ring->next_to_clean = 0;
 	rx_ring->next_to_use = 0;
+	rx_ring->rx_offset = ixgbe_rx_offset(rx_ring);
 
 	/* XDP RX-queue info */
 	if (xdp_rxq_info_reg(&rx_ring->xdp_rxq, adapter->netdev,
-- 
2.26.2

Re: [PATCH net-next 02/11] i40e: drop misleading function comments

[Alexander Duyck]

On Fri, Feb 12, 2021 at 2:46 PM Tony Nguyen <anthony.l.nguyen@intel.com> wrote:
>
> From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
>
> i40e_cleanup_headers has a statement about check against skb being
> linear or not which is not relevant anymore, so let's remove it.
>
> Same case for i40e_can_reuse_rx_page, it references things that are not
> present there anymore.
>
> Reviewed-by: Björn Töpel <bjorn.topel@intel.com>
> Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
> Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
> ---
>  drivers/net/ethernet/intel/i40e/i40e_txrx.c | 33 ++++-----------------
>  1 file changed, 6 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
> index 3d24c6032616..5f6aa13e85ca 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
> +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
> @@ -1963,9 +1963,6 @@ void i40e_process_skb_fields(struct i40e_ring *rx_ring,
>   * @skb: pointer to current skb being fixed
>   * @rx_desc: pointer to the EOP Rx descriptor
>   *
> - * Also address the case where we are pulling data in on pages only
> - * and as such no data is present in the skb header.
> - *
>   * In addition if skb is not at least 60 bytes we need to pad it so that
>   * it is large enough to qualify as a valid Ethernet frame.
>   *
> @@ -1998,33 +1995,15 @@ static bool i40e_cleanup_headers(struct i40e_ring *rx_ring, struct sk_buff *skb,
>  }
>
>  /**
> - * i40e_can_reuse_rx_page - Determine if this page can be reused by
> - * the adapter for another receive
> - *
> + * i40e_can_reuse_rx_page - Determine if page can be reused for another Rx
>   * @rx_buffer: buffer containing the page
>   * @rx_buffer_pgcnt: buffer page refcount pre xdp_do_redirect() call
>   *
> - * If page is reusable, rx_buffer->page_offset is adjusted to point to
> - * an unused region in the page.
> - *
> - * For small pages, @truesize will be a constant value, half the size
> - * of the memory at page.  We'll attempt to alternate between high and
> - * low halves of the page, with one half ready for use by the hardware
> - * and the other half being consumed by the stack.  We use the page
> - * ref count to determine whether the stack has finished consuming the
> - * portion of this page that was passed up with a previous packet.  If
> - * the page ref count is >1, we'll assume the "other" half page is
> - * still busy, and this page cannot be reused.
> - *
> - * For larger pages, @truesize will be the actual space used by the
> - * received packet (adjusted upward to an even multiple of the cache
> - * line size).  This will advance through the page by the amount
> - * actually consumed by the received packets while there is still
> - * space for a buffer.  Each region of larger pages will be used at
> - * most once, after which the page will not be reused.
> - *
> - * In either case, if the page is reusable its refcount is increased.
> - **/
> + * If page is reusable, we have a green light for calling i40e_reuse_rx_page,
> + * which will assign the current buffer to the buffer that next_to_alloc is
> + * pointing to; otherwise, the DMA mapping needs to be destroyed and
> + * page freed
> + */
>  static bool i40e_can_reuse_rx_page(struct i40e_rx_buffer *rx_buffer,
>                                    int rx_buffer_pgcnt)
>  {

So this lost all of the context for why or how the function works.

You should probably call out that for 4K pages it is using a simple
page count where if the count hits 2 we have to return false, and if
the page is bigger than 4K we have to check the remaining unused
buffer to determine if we will fail or not.

Re: [PATCH net-next 00/11][pull request] 40GbE Intel Wired LAN Driver Updates 2021-02-12

[patchwork-bot+netdevbpf]

Hello:

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

On Fri, 12 Feb 2021 14:39:41 -0800 you wrote:
> This series contains updates to i40e, ice, and ixgbe drivers.
> 
> Maciej does cleanups on the following drivers.
> For i40e, removes redundant check for XDP prog, cleans up no longer
> relevant information, and removes an unused function argument.
> For ice, removes local variable use, instead returning values directly.
> Moves skb pointer from buffer to ring and removes an unneeded check for
> xdp_prog in zero copy path. Also removes a redundant MTU check when
> changing it.
> For i40e, ice, and ixgbe, stores the rx_offset in the Rx ring as
> the value is constant so there's no need for continual calls.
> 
> [...]

Here is the summary with links:
  - [net-next,01/11] i40e: drop redundant check when setting xdp prog
    https://git.kernel.org/netdev/net-next/c/99f097270a18
  - [net-next,02/11] i40e: drop misleading function comments
    https://git.kernel.org/netdev/net-next/c/4a14994a921e
  - [net-next,03/11] i40e: adjust i40e_is_non_eop
    https://git.kernel.org/netdev/net-next/c/d06e2f05b4f1
  - [net-next,04/11] ice: simplify ice_run_xdp
    https://git.kernel.org/netdev/net-next/c/59c97d1b51b1
  - [net-next,05/11] ice: move skb pointer from rx_buf to rx_ring
    https://git.kernel.org/netdev/net-next/c/29b82f2a09d5
  - [net-next,06/11] ice: remove redundant checks in ice_change_mtu
    https://git.kernel.org/netdev/net-next/c/43a925e49d46
  - [net-next,07/11] ice: skip NULL check against XDP prog in ZC path
    https://git.kernel.org/netdev/net-next/c/5c57e507f247
  - [net-next,08/11] i40e: Simplify the do-while allocation loop
    https://git.kernel.org/netdev/net-next/c/f892a9af0cd8
  - [net-next,09/11] i40e: store the result of i40e_rx_offset() onto i40e_ring
    https://git.kernel.org/netdev/net-next/c/f7bb0d71d658
  - [net-next,10/11] ice: store the result of ice_rx_offset() onto ice_ring
    https://git.kernel.org/netdev/net-next/c/f1b1f409bf79
  - [net-next,11/11] ixgbe: store the result of ixgbe_rx_offset() onto ixgbe_ring
    https://git.kernel.org/netdev/net-next/c/c0d4e9d223c5

You are awesome, thank you!
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