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 2B47039FCC5; Sat, 12 Sep 2026 18:17:24 +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=1789237045; cv=none; b=HVmJcE6IOaK0Mo1EvbACqigSjO1ZRpIZaNzuwwcpUc7kIerjz1N8gxPbi+ri0bvfuQigxsP5LeOjyT8qt7jXBXE+3IgT4f1bY95w/GV42YluOxoW5ocn+KzbuQ1QD9B4AIvxaWEt2sGYG7arIMdl3o6zgaN6lk5/U0EKm/5SfEQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789237045; c=relaxed/simple; bh=4TSsBdUfD7sfEy4cPa56pFyPzFJ+E/i6Ujilkec4jOk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=HB5pn1Bk1j+FNYu4a40ZjfnWMvJnjuqetNE902jTgv3gcSK0Z1UG47N3562YiGZaQO4xOJ51f96mbsY6cHfWFavtrI22tpeyUT5/ILN9GEgSDwVbqGZvCVMBZsPpROdFvQikgJpvGpQMEPGWFsF3k5QyHyLYag7BV4c/LX7Sr44= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=QlTdE5hV; 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="QlTdE5hV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 15DC31F000FF; Sat, 12 Sep 2026 18:17:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789237044; bh=saJ/gHy4jeUOHbJmQ1OlSGvxj9shf1iFQ9H2Mu0ffKI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=QlTdE5hVXOm/bFN+xxgUp2pT1zEebRD++z5Y4CKNJ1BMJv1dTq2fXcSblvUuaLmjo +IlzaVuXgfFPCxruu7ZwXdOsAONLPE5gQeSBZeht+TW7Fe+9P+bvM/O8/LZBW6aWzc ruVCRY8P6YK0JeUG50zP5qD1C9marYdcl4IpuKto= 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 5.15 180/935] NTB: ntb_transport: Recycle TX entries before client callbacks Date: Sat, 12 Sep 2026 08:53:30 +0200 Message-ID: <20260912065530.945935007@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065526.833703348@linuxfoundation.org> References: <20260912065526.833703348@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 5.15-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 @@ -1732,9 +1732,16 @@ 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) { @@ -1774,15 +1781,13 @@ 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(struct ntb_queue_entry *entry, void __iomem *offset)