From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.codeaurora.org by pdx-caf-mail.web.codeaurora.org (Dovecot) with LMTP id a05CCto9GVvtRQAAmS7hNA ; Thu, 07 Jun 2018 14:15:50 +0000 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 8D5ED608B8; Thu, 7 Jun 2018 14:15:50 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on pdx-caf-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by smtp.codeaurora.org (Postfix) with ESMTP id 091F7602FC; Thu, 7 Jun 2018 14:15:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 091F7602FC Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932774AbeFGOJY (ORCPT + 25 others); Thu, 7 Jun 2018 10:09:24 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:39238 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933006AbeFGOJE (ORCPT ); Thu, 7 Jun 2018 10:09:04 -0400 Received: from [148.252.241.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1fQvb4-0005a0-CU; Thu, 07 Jun 2018 15:09:02 +0100 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1fQvb0-0002oS-V4; Thu, 07 Jun 2018 15:08:58 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Moshe Shemesh" , "David S. Miller" , "Tariq Toukan" Date: Thu, 07 Jun 2018 15:05:21 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 090/410] net/mlx4_core: Cleanup FMR unmapping flow In-Reply-To: X-SA-Exim-Connect-IP: 148.252.241.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.57-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Tariq Toukan commit fd4a3e2828b4ca35aef40e5bdc1ed7d87b3cb50a upstream. Remove redundant and not essential operations in fmr unmap/free. According to device spec, in FMR unmap it is sufficient to set ownership bit to SW. This allows remapping afterwards. Fixes: 8ad11fb6b073 ("IB/mlx4: Implement FMRs") Signed-off-by: Tariq Toukan Signed-off-by: Moshe Shemesh Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- drivers/net/ethernet/mellanox/mlx4/mr.c | 40 +++++++++++++------------ 1 file changed, 21 insertions(+), 19 deletions(-) --- a/drivers/net/ethernet/mellanox/mlx4/mr.c +++ b/drivers/net/ethernet/mellanox/mlx4/mr.c @@ -944,30 +944,16 @@ EXPORT_SYMBOL_GPL(mlx4_fmr_enable); void mlx4_fmr_unmap(struct mlx4_dev *dev, struct mlx4_fmr *fmr, u32 *lkey, u32 *rkey) { - struct mlx4_cmd_mailbox *mailbox; - int err; - if (!fmr->maps) return; - fmr->maps = 0; + /* To unmap: it is sufficient to take back ownership from HW */ + *(u8 *)fmr->mpt = MLX4_MPT_STATUS_SW; - mailbox = mlx4_alloc_cmd_mailbox(dev); - if (IS_ERR(mailbox)) { - err = PTR_ERR(mailbox); - pr_warn("mlx4_ib: mlx4_alloc_cmd_mailbox failed (%d)\n", err); - return; - } + /* Make sure MPT status is visible */ + wmb(); - err = mlx4_HW2SW_MPT(dev, NULL, - key_to_hw_index(fmr->mr.key) & - (dev->caps.num_mpts - 1)); - mlx4_free_cmd_mailbox(dev, mailbox); - if (err) { - pr_warn("mlx4_ib: mlx4_HW2SW_MPT failed (%d)\n", err); - return; - } - fmr->mr.enabled = MLX4_MPT_EN_SW; + fmr->maps = 0; } EXPORT_SYMBOL_GPL(mlx4_fmr_unmap); @@ -977,6 +963,22 @@ int mlx4_fmr_free(struct mlx4_dev *dev, if (fmr->maps) return -EBUSY; + if (fmr->mr.enabled == MLX4_MPT_EN_HW) { + /* In case of FMR was enabled and unmapped + * make sure to give ownership of MPT back to HW + * so HW2SW_MPT command will success. + */ + *(u8 *)fmr->mpt = MLX4_MPT_STATUS_SW; + /* Make sure MPT status is visible before changing MPT fields */ + wmb(); + fmr->mpt->length = 0; + fmr->mpt->start = 0; + /* Make sure MPT data is visible after changing MPT status */ + wmb(); + *(u8 *)fmr->mpt = MLX4_MPT_STATUS_HW; + /* make sure MPT status is visible */ + wmb(); + } ret = mlx4_mr_free(dev, &fmr->mr); if (ret)