From patchwork Mon Jan 24 18:45:11 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 535677 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3EE4EC433EF for ; Mon, 24 Jan 2022 20:54:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1442270AbiAXUyE (ORCPT ); Mon, 24 Jan 2022 15:54:04 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:44792 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1392503AbiAXUvX (ORCPT ); Mon, 24 Jan 2022 15:51:23 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 26A6060C3E; Mon, 24 Jan 2022 20:51:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id ECE84C340E5; Mon, 24 Jan 2022 20:51:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643057482; bh=DKaIZ44jXhAHBBxgsqnKrT5Vc0etjfMDYpjpcuu0RIM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0ORQzSfptMvryCu3iVN7w22Ghkbc3rn2OY8GEbhL37ogeo4OGBB+rU2mHjJcgg/78 uYRQccBCJ6cQ9HADckGwt8NTBEj4iBZOd5SGhX0WonkpxOWzUoQnYNN7pA6x1UqzXG 9xWIqpdEhCwWQdSuTDaMHhJwvYJ1mB0m8P2pObVU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Robert Hancock , "David S. Miller" Subject: [PATCH 5.15 794/846] net: axienet: add missing memory barriers Date: Mon, 24 Jan 2022 19:45:11 +0100 Message-Id: <20220124184128.347262824@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124184100.867127425@linuxfoundation.org> References: <20220124184100.867127425@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Robert Hancock commit 95978df6fa328df619c15312e65ece469c2be2d2 upstream. This driver was missing some required memory barriers: Use dma_rmb to ensure we see all updates to the descriptor after we see that an entry has been completed. Use wmb and rmb to avoid stale descriptor status between the TX path and TX complete IRQ path. Fixes: 8a3b7a252dca9 ("drivers/net/ethernet/xilinx: added Xilinx AXI Ethernet driver") Signed-off-by: Robert Hancock Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/xilinx/xilinx_axienet_main.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c @@ -632,6 +632,8 @@ static int axienet_free_tx_chain(struct if (nr_bds == -1 && !(status & XAXIDMA_BD_STS_COMPLETE_MASK)) break; + /* Ensure we see complete descriptor update */ + dma_rmb(); phys = desc_get_phys_addr(lp, cur_p); dma_unmap_single(ndev->dev.parent, phys, (cur_p->cntrl & XAXIDMA_BD_CTRL_LENGTH_MASK), @@ -645,8 +647,10 @@ static int axienet_free_tx_chain(struct cur_p->app1 = 0; cur_p->app2 = 0; cur_p->app4 = 0; - cur_p->status = 0; cur_p->skb = NULL; + /* ensure our transmit path and device don't prematurely see status cleared */ + wmb(); + cur_p->status = 0; if (sizep) *sizep += status & XAXIDMA_BD_STS_ACTUAL_LEN_MASK; @@ -704,6 +708,9 @@ static inline int axienet_check_tx_bd_sp int num_frag) { struct axidma_bd *cur_p; + + /* Ensure we see all descriptor updates from device or TX IRQ path */ + rmb(); cur_p = &lp->tx_bd_v[(lp->tx_bd_tail + num_frag) % lp->tx_bd_num]; if (cur_p->status & XAXIDMA_BD_STS_ALL_MASK) return NETDEV_TX_BUSY; @@ -843,6 +850,8 @@ static void axienet_recv(struct net_devi tail_p = lp->rx_bd_p + sizeof(*lp->rx_bd_v) * lp->rx_bd_ci; + /* Ensure we see complete descriptor update */ + dma_rmb(); phys = desc_get_phys_addr(lp, cur_p); dma_unmap_single(ndev->dev.parent, phys, lp->max_frm_size, DMA_FROM_DEVICE);