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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Denis Bolotin <denis.bolotin@cavium.com>,
        Michal Kalderon <michal.kalderon@cavium.com>,
        "David S. Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 24/46] qed: Fix blocking/unlimited SPQ entries leak
Date:   Mon, 26 Nov 2018 11:51:13 +0100
Message-Id: <20181126105048.475077429@linuxfoundation.org>
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4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

[ Upstream commit 2632f22ebd08da249c2017962a199a0cfb2324bf ]

When there are no SPQ entries left in the free_pool, new entries are
allocated and are added to the unlimited list. When an entry in the pool
is available, the content is copied from the original entry, and the new
entry is sent to the device. qed_spq_post() is not aware of that, so the
additional entry is stored in the original entry as p_post_ent, which can
later be returned to the pool.

Signed-off-by: Denis Bolotin <denis.bolotin@cavium.com>
Signed-off-by: Michal Kalderon <michal.kalderon@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/qlogic/qed/qed_sp.h  |  3 ++
 drivers/net/ethernet/qlogic/qed/qed_spq.c | 57 ++++++++++++-----------
 2 files changed, 33 insertions(+), 27 deletions(-)

diff --git a/drivers/net/ethernet/qlogic/qed/qed_sp.h b/drivers/net/ethernet/qlogic/qed/qed_sp.h
index b2c08e4d2a9b..bae7b7f9b1cf 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_sp.h
+++ b/drivers/net/ethernet/qlogic/qed/qed_sp.h
@@ -132,6 +132,9 @@ struct qed_spq_entry {
 	enum spq_mode			comp_mode;
 	struct qed_spq_comp_cb		comp_cb;
 	struct qed_spq_comp_done	comp_done; /* SPQ_MODE_EBLOCK */
+
+	/* Posted entry for unlimited list entry in EBLOCK mode */
+	struct qed_spq_entry		*post_ent;
 };
 
 struct qed_eq {
diff --git a/drivers/net/ethernet/qlogic/qed/qed_spq.c b/drivers/net/ethernet/qlogic/qed/qed_spq.c
index 9fbaf9429fd0..80c8c7f0d932 100644
--- a/drivers/net/ethernet/qlogic/qed/qed_spq.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_spq.c
@@ -595,6 +595,8 @@ static int qed_spq_add_entry(struct qed_hwfn *p_hwfn,
 			/* EBLOCK responsible to free the allocated p_ent */
 			if (p_ent->comp_mode != QED_SPQ_MODE_EBLOCK)
 				kfree(p_ent);
+			else
+				p_ent->post_ent = p_en2;
 
 			p_ent = p_en2;
 		}
@@ -678,6 +680,25 @@ static int qed_spq_pend_post(struct qed_hwfn *p_hwfn)
 				 SPQ_HIGH_PRI_RESERVE_DEFAULT);
 }
 
+/* Avoid overriding of SPQ entries when getting out-of-order completions, by
+ * marking the completions in a bitmap and increasing the chain consumer only
+ * for the first successive completed entries.
+ */
+static void qed_spq_comp_bmap_update(struct qed_hwfn *p_hwfn, __le16 echo)
+{
+	u16 pos = le16_to_cpu(echo) % SPQ_RING_SIZE;
+	struct qed_spq *p_spq = p_hwfn->p_spq;
+
+	__set_bit(pos, p_spq->p_comp_bitmap);
+	while (test_bit(p_spq->comp_bitmap_idx,
+			p_spq->p_comp_bitmap)) {
+		__clear_bit(p_spq->comp_bitmap_idx,
+			    p_spq->p_comp_bitmap);
+		p_spq->comp_bitmap_idx++;
+		qed_chain_return_produced(&p_spq->chain);
+	}
+}
+
 int qed_spq_post(struct qed_hwfn *p_hwfn,
 		 struct qed_spq_entry *p_ent, u8 *fw_return_code)
 {
@@ -728,11 +749,12 @@ int qed_spq_post(struct qed_hwfn *p_hwfn,
 		rc = qed_spq_block(p_hwfn, p_ent, fw_return_code);
 
 		if (p_ent->queue == &p_spq->unlimited_pending) {
-			/* This is an allocated p_ent which does not need to
-			 * return to pool.
-			 */
+			struct qed_spq_entry *p_post_ent = p_ent->post_ent;
+
 			kfree(p_ent);
-			return rc;
+
+			/* Return the entry which was actually posted */
+			p_ent = p_post_ent;
 		}
 
 		if (rc)
@@ -746,7 +768,7 @@ int qed_spq_post(struct qed_hwfn *p_hwfn,
 spq_post_fail2:
 	spin_lock_bh(&p_spq->lock);
 	list_del(&p_ent->list);
-	qed_chain_return_produced(&p_spq->chain);
+	qed_spq_comp_bmap_update(p_hwfn, p_ent->elem.hdr.echo);
 
 spq_post_fail:
 	/* return to the free pool */
@@ -778,25 +800,8 @@ int qed_spq_completion(struct qed_hwfn *p_hwfn,
 	spin_lock_bh(&p_spq->lock);
 	list_for_each_entry_safe(p_ent, tmp, &p_spq->completion_pending, list) {
 		if (p_ent->elem.hdr.echo == echo) {
-			u16 pos = le16_to_cpu(echo) % SPQ_RING_SIZE;
-
 			list_del(&p_ent->list);
-
-			/* Avoid overriding of SPQ entries when getting
-			 * out-of-order completions, by marking the completions
-			 * in a bitmap and increasing the chain consumer only
-			 * for the first successive completed entries.
-			 */
-			__set_bit(pos, p_spq->p_comp_bitmap);
-
-			while (test_bit(p_spq->comp_bitmap_idx,
-					p_spq->p_comp_bitmap)) {
-				__clear_bit(p_spq->comp_bitmap_idx,
-					    p_spq->p_comp_bitmap);
-				p_spq->comp_bitmap_idx++;
-				qed_chain_return_produced(&p_spq->chain);
-			}
-
+			qed_spq_comp_bmap_update(p_hwfn, echo);
 			p_spq->comp_count++;
 			found = p_ent;
 			break;
@@ -835,11 +840,9 @@ int qed_spq_completion(struct qed_hwfn *p_hwfn,
 			   QED_MSG_SPQ,
 			   "Got a completion without a callback function\n");
 
-	if ((found->comp_mode != QED_SPQ_MODE_EBLOCK) ||
-	    (found->queue == &p_spq->unlimited_pending))
+	if (found->comp_mode != QED_SPQ_MODE_EBLOCK)
 		/* EBLOCK  is responsible for returning its own entry into the
-		 * free list, unless it originally added the entry into the
-		 * unlimited pending list.
+		 * free list.
 		 */
 		qed_spq_return_entry(p_hwfn, found);
 
-- 
2.17.1