From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7265A37DAD0; Fri, 4 Sep 2026 05:33:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788499991; cv=none; b=Id3+r1WVOmmLDxC0k2IMofYG5IC3qvnSgz/h2jFVzwZeeq66ii5sG8ZQx6SmWnqky2BQ9UI+4o14fBiR+88ER4A0XyqZPo+oTGojAhW+UoKpqvKZohXRAUKz7xI+w4+aN1RBsSaSkfLXtf2XD8QlNMJINinWDF07jPqGoV+aNas= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788499991; c=relaxed/simple; bh=Z+/+z2W4ZOPKljcoUM5C8yq1KNAgPPOd68XIf6Lekk8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=HBd5uNwy49Bg21i4WV1kBuD3mMgE04X8F/dF+Nhl2x6gD7JtCoRob+ZTQPPXgES1iuDyTreeAHpu/HcPvG0VBTi6V/tdBc164c1rLusoc1MdQ2uVHlJeiqtw9yDhbuamhlQiUCHMrXpyu1nF0nXLgiuczQi+NjeMVwURBYmOX8s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=kSrmrxrF; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="kSrmrxrF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CABBD1F00A3D; Fri, 4 Sep 2026 05:33:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788499990; bh=RXPk9jsbkpdjVk07hY/6tPkzTUcf4tlkKAcXY27MBrc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=kSrmrxrFoPlT4lOLAM56Yi4DfoWPuvdYjZ49WsuG8A1kDReWSMruB6sOZQQQFLQjY qrSiBNME4GLa1LTZwr1rXfQLAeIwtGvjRf5gGjtMhGlt8mnEd8vP8QtEaMlZqBVCAp DLiR05YB724BOPb3xh/T/JT/EZ/2u52YY1ermR4w= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Koichiro Den , Dave Jiang , Jakub Kicinski Subject: [PATCH 7.2 612/713] NTB: ntb_transport: Recycle TX entries before client callbacks Date: Fri, 4 Sep 2026 06:59:40 +0200 Message-ID: <20260904045817.545129107@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260904045803.810145556@linuxfoundation.org> References: <20260904045803.810145556@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Koichiro Den commit 256496397287334a19ed80ec7be92bffcae76b9d upstream. ntb_tx_copy_callback() invokes the client callback before returning the entry to tx_free_q. The callback may wake a stopped client queue, only for the next enqueue to find no local entry and return -EBUSY. The window is narrow, but the retry is unnecessary. Save the callback data and length, then return the entry to tx_free_q before invoking the client. A completion callback then means both the client buffer and transport entry are ready for reuse. Fixes: fce8a7bb5b4b ("PCI-Express Non-Transparent Bridge Support") Cc: stable@vger.kernel.org Signed-off-by: Koichiro Den Reviewed-by: Dave Jiang Link: https://patch.msgid.link/20260817053519.4135287-2-den@valinux.co.jp Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/ntb/ntb_transport.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) --- a/drivers/ntb/ntb_transport.c +++ b/drivers/ntb/ntb_transport.c @@ -1719,9 +1719,16 @@ static void ntb_transport_rxc_db(unsigne static void ntb_tx_copy_callback(void *data, const struct dmaengine_result *res) { + struct ntb_payload_header __iomem *hdr; struct ntb_queue_entry *entry = data; - struct ntb_transport_qp *qp = entry->qp; - struct ntb_payload_header __iomem *hdr = entry->tx_hdr; + struct ntb_transport_qp *qp; + unsigned int len; + void *cb_data; + + qp = entry->qp; + hdr = entry->tx_hdr; + cb_data = entry->cb_data; + len = entry->len; /* we need to check DMA results if we are using DMA */ if (res) { @@ -1768,15 +1775,13 @@ static void ntb_tx_copy_callback(void *d * "link down" or similar. Since no payload is being sent in these * cases, there is nothing to add to the completion queue. */ - if (entry->len > 0) { - qp->tx_bytes += entry->len; - - if (qp->tx_handler) - qp->tx_handler(qp, qp->cb_data, entry->cb_data, - entry->len); - } + if (len > 0) + qp->tx_bytes += len; ntb_list_add(&qp->ntb_tx_free_q_lock, &entry->entry, &qp->tx_free_q); + + if (len > 0 && qp->tx_handler) + qp->tx_handler(qp, qp->cb_data, cb_data, len); } static void ntb_memcpy_tx_on_stack(struct ntb_queue_entry *entry, void __iomem *offset)