netdev - [PATCH net v2] bnxt_en: update xdp_rxq

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Message-Id: <20240721053554.1233549-1-ap420073@gmail.com>
Date: Sun, 21 Jul 2024 05:35:54 +0000
From: Taehee Yoo <ap420073@...il.com>
To: davem@...emloft.net,
	kuba@...nel.org,
	pabeni@...hat.com,
	edumazet@...gle.com,
	michael.chan@...adcom.com,
	netdev@...r.kernel.org
Cc: ap420073@...il.com,
	somnath.kotur@...adcom.com,
	dw@...idwei.uk,
	horms@...nel.org
Subject: [PATCH net v2] bnxt_en: update xdp_rxq_info in queue restart logic

When the netdev_rx_queue_restart() restarts queues, the bnxt_en driver
updates(creates and deletes) a page_pool.
But it doesn't update xdp_rxq_info, so the xdp_rxq_info is still
connected to an old page_pool.
So, bnxt_rx_ring_info->page_pool indicates a new page_pool, but
bnxt_rx_ring_info->xdp_rxq is still connected to an old page_pool.

An old page_pool is no longer used so it is supposed to be
deleted by page_pool_destroy() but it isn't.
Because the xdp_rxq_info is holding the reference count for it and the
xdp_rxq_info is not updated, an old page_pool will not be deleted in
the queue restart logic.

Before restarting 1 queue:
./tools/net/ynl/samples/page-pool
enp10s0f1np1[6] page pools: 4 (zombies: 0)
	refs: 8192 bytes: 33554432 (refs: 0 bytes: 0)
	recycling: 0.0% (alloc: 128:8048 recycle: 0:0)

After restarting 1 queue:
./tools/net/ynl/samples/page-pool
enp10s0f1np1[6] page pools: 5 (zombies: 0)
	refs: 10240 bytes: 41943040 (refs: 0 bytes: 0)
	recycling: 20.0% (alloc: 160:10080 recycle: 1920:128)

Before restarting queues, an interface has 4 page_pools.
After restarting one queue, an interface has 5 page_pools, but it
should be 4, not 5.
The reason is that queue restarting logic creates a new page_pool and
an old page_pool is not deleted due to the absence of an update of
xdp_rxq_info logic.

Fixes: 2d694c27d32e ("bnxt_en: implement netdev_queue_mgmt_ops")
Signed-off-by: Taehee Yoo <ap420073@...il.com>
---

v2:
 - Do not use memcpy in the bnxt_queue_start
 - Call xdp_rxq_info_unreg() before page_pool_destroy() in the
   bnxt_queue_mem_free().

 drivers/net/ethernet/broadcom/bnxt/bnxt.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index bb3be33c1bbd..ffa74c26ee53 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -4052,6 +4052,7 @@ static void bnxt_reset_rx_ring_struct(struct bnxt *bp,
 
 	rxr->page_pool->p.napi = NULL;
 	rxr->page_pool = NULL;
+	memset(&rxr->xdp_rxq, 0, sizeof(struct xdp_rxq_info));
 
 	ring = &rxr->rx_ring_struct;
 	rmem = &ring->ring_mem;
@@ -15018,6 +15019,16 @@ static int bnxt_queue_mem_alloc(struct net_device *dev, void *qmem, int idx)
 	if (rc)
 		return rc;
 
+	rc = xdp_rxq_info_reg(&clone->xdp_rxq, bp->dev, idx, 0);
+	if (rc < 0)
+		goto err_page_pool_destroy;
+
+	rc = xdp_rxq_info_reg_mem_model(&clone->xdp_rxq,
+					MEM_TYPE_PAGE_POOL,
+					clone->page_pool);
+	if (rc)
+		goto err_rxq_info_unreg;
+
 	ring = &clone->rx_ring_struct;
 	rc = bnxt_alloc_ring(bp, &ring->ring_mem);
 	if (rc)
@@ -15047,6 +15058,9 @@ static int bnxt_queue_mem_alloc(struct net_device *dev, void *qmem, int idx)
 	bnxt_free_ring(bp, &clone->rx_agg_ring_struct.ring_mem);
 err_free_rx_ring:
 	bnxt_free_ring(bp, &clone->rx_ring_struct.ring_mem);
+err_rxq_info_unreg:
+	xdp_rxq_info_unreg(&clone->xdp_rxq);
+err_page_pool_destroy:
 	clone->page_pool->p.napi = NULL;
 	page_pool_destroy(clone->page_pool);
 	clone->page_pool = NULL;
@@ -15062,6 +15076,8 @@ static void bnxt_queue_mem_free(struct net_device *dev, void *qmem)
 	bnxt_free_one_rx_ring(bp, rxr);
 	bnxt_free_one_rx_agg_ring(bp, rxr);
 
+	xdp_rxq_info_unreg(&rxr->xdp_rxq);
+
 	page_pool_destroy(rxr->page_pool);
 	rxr->page_pool = NULL;
 
@@ -15145,6 +15161,7 @@ static int bnxt_queue_start(struct net_device *dev, void *qmem, int idx)
 	rxr->rx_sw_agg_prod = clone->rx_sw_agg_prod;
 	rxr->rx_next_cons = clone->rx_next_cons;
 	rxr->page_pool = clone->page_pool;
+	rxr->xdp_rxq = clone->xdp_rxq;
 
 	bnxt_copy_rx_ring(bp, rxr, clone);
 
-- 
2.34.1