From patchwork Tue Jan 28 14:08:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 232607 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A957BC2D0DB for ; Tue, 28 Jan 2020 14:31:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6E70C2468E for ; Tue, 28 Jan 2020 14:31:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580221872; bh=oOMNFRsG/auc89cM5gXtsixkUIpHDkaDd6xkF0X7Jjg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=OEDXauvyIyU1dVnUxve7ztMrqBTnIx5lKCHuf77vUW3nVMoPnVd5LVC47rglm9aAt qnPNojBnALhsyBsSBo8oOx+8YGP5+lBhJC66TPAE9FmZmuZaGAvTiKt4aCzhc6OWm7 I2A6+mlLScCcYAnQLUlBJFmHtCwgqOf80WA8HvdQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387471AbgA1O2P (ORCPT ); Tue, 28 Jan 2020 09:28:15 -0500 Received: from mail.kernel.org ([198.145.29.99]:56090 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728706AbgA1O2L (ORCPT ); Tue, 28 Jan 2020 09:28:11 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 00A51207FD; Tue, 28 Jan 2020 14:28:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580221690; bh=oOMNFRsG/auc89cM5gXtsixkUIpHDkaDd6xkF0X7Jjg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UhJhRHmIynzFO99ipYIBuq1i8ci1jgS7EwM6noFknsOyftzhY29/hEHjVb3wxnTdX CbzddfRfZZ5tfW44NYjusvZhhDao3+siB8zvq3HPTujaAY18pdKfQ/7zDlzXvInp0k bqPVRpqUu6NIUUdsoTWTvwGyX5f1l80qomK1KF7w= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stan Johnson , Finn Thain , "David S. Miller" Subject: [PATCH 4.19 51/92] net/sonic: Fix receive buffer replenishment Date: Tue, 28 Jan 2020 15:08:19 +0100 Message-Id: <20200128135815.675413417@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200128135809.344954797@linuxfoundation.org> References: <20200128135809.344954797@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Finn Thain commit 89ba879e95582d3bba55081e45b5409e883312ca upstream. As soon as the driver is finished with a receive buffer it allocs a new one and overwrites the corresponding RRA entry with a new buffer pointer. Problem is, the buffer pointer is split across two word-sized registers. It can't be updated in one atomic store. So this operation races with the chip while it stores received packets and advances its RRP register. This could result in memory corruption by a DMA write. Avoid this problem by adding buffers only at the location given by the RWP register, in accordance with the National Semiconductor datasheet. Re-factor this code into separate functions to calculate a RRA pointer and to update the RWP. Fixes: efcce839360f ("[PATCH] macsonic/jazzsonic network drivers update") Tested-by: Stan Johnson Signed-off-by: Finn Thain Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/natsemi/sonic.c | 150 ++++++++++++++++++++--------------- drivers/net/ethernet/natsemi/sonic.h | 18 +++- 2 files changed, 105 insertions(+), 63 deletions(-) --- a/drivers/net/ethernet/natsemi/sonic.c +++ b/drivers/net/ethernet/natsemi/sonic.c @@ -427,6 +427,59 @@ static int index_from_addr(struct sonic_ return -ENOENT; } +/* Allocate and map a new skb to be used as a receive buffer. */ +static bool sonic_alloc_rb(struct net_device *dev, struct sonic_local *lp, + struct sk_buff **new_skb, dma_addr_t *new_addr) +{ + *new_skb = netdev_alloc_skb(dev, SONIC_RBSIZE + 2); + if (!*new_skb) + return false; + + if (SONIC_BUS_SCALE(lp->dma_bitmode) == 2) + skb_reserve(*new_skb, 2); + + *new_addr = dma_map_single(lp->device, skb_put(*new_skb, SONIC_RBSIZE), + SONIC_RBSIZE, DMA_FROM_DEVICE); + if (!*new_addr) { + dev_kfree_skb(*new_skb); + *new_skb = NULL; + return false; + } + + return true; +} + +/* Place a new receive resource in the Receive Resource Area and update RWP. */ +static void sonic_update_rra(struct net_device *dev, struct sonic_local *lp, + dma_addr_t old_addr, dma_addr_t new_addr) +{ + unsigned int entry = sonic_rr_entry(dev, SONIC_READ(SONIC_RWP)); + unsigned int end = sonic_rr_entry(dev, SONIC_READ(SONIC_RRP)); + u32 buf; + + /* The resources in the range [RRP, RWP) belong to the SONIC. This loop + * scans the other resources in the RRA, those in the range [RWP, RRP). + */ + do { + buf = (sonic_rra_get(dev, entry, SONIC_RR_BUFADR_H) << 16) | + sonic_rra_get(dev, entry, SONIC_RR_BUFADR_L); + + if (buf == old_addr) + break; + + entry = (entry + 1) & SONIC_RRS_MASK; + } while (entry != end); + + WARN_ONCE(buf != old_addr, "failed to find resource!\n"); + + sonic_rra_put(dev, entry, SONIC_RR_BUFADR_H, new_addr >> 16); + sonic_rra_put(dev, entry, SONIC_RR_BUFADR_L, new_addr & 0xffff); + + entry = (entry + 1) & SONIC_RRS_MASK; + + SONIC_WRITE(SONIC_RWP, sonic_rr_addr(dev, entry)); +} + /* * We have a good packet(s), pass it/them up the network stack. */ @@ -435,18 +488,15 @@ static void sonic_rx(struct net_device * struct sonic_local *lp = netdev_priv(dev); int entry = lp->cur_rx; int prev_entry = lp->eol_rx; + bool rbe = false; while (sonic_rda_get(dev, entry, SONIC_RD_IN_USE) == 0) { - struct sk_buff *used_skb; - struct sk_buff *new_skb; - dma_addr_t new_laddr; - u16 bufadr_l; - u16 bufadr_h; - int pkt_len; u16 status = sonic_rda_get(dev, entry, SONIC_RD_STATUS); /* If the RD has LPKT set, the chip has finished with the RB */ if ((status & SONIC_RCR_PRX) && (status & SONIC_RCR_LPKT)) { + struct sk_buff *new_skb; + dma_addr_t new_laddr; u32 addr = (sonic_rda_get(dev, entry, SONIC_RD_PKTPTR_H) << 16) | sonic_rda_get(dev, entry, SONIC_RD_PKTPTR_L); @@ -457,55 +507,35 @@ static void sonic_rx(struct net_device * break; } - /* Malloc up new buffer. */ - new_skb = netdev_alloc_skb(dev, SONIC_RBSIZE + 2); - if (new_skb == NULL) { + if (sonic_alloc_rb(dev, lp, &new_skb, &new_laddr)) { + struct sk_buff *used_skb = lp->rx_skb[i]; + int pkt_len; + + /* Pass the used buffer up the stack */ + dma_unmap_single(lp->device, addr, SONIC_RBSIZE, + DMA_FROM_DEVICE); + + pkt_len = sonic_rda_get(dev, entry, + SONIC_RD_PKTLEN); + skb_trim(used_skb, pkt_len); + used_skb->protocol = eth_type_trans(used_skb, + dev); + netif_rx(used_skb); + lp->stats.rx_packets++; + lp->stats.rx_bytes += pkt_len; + + lp->rx_skb[i] = new_skb; + lp->rx_laddr[i] = new_laddr; + } else { + /* Failed to obtain a new buffer so re-use it */ + new_laddr = addr; lp->stats.rx_dropped++; - break; } - /* provide 16 byte IP header alignment unless DMA requires otherwise */ - if(SONIC_BUS_SCALE(lp->dma_bitmode) == 2) - skb_reserve(new_skb, 2); - - new_laddr = dma_map_single(lp->device, skb_put(new_skb, SONIC_RBSIZE), - SONIC_RBSIZE, DMA_FROM_DEVICE); - if (!new_laddr) { - dev_kfree_skb(new_skb); - printk(KERN_ERR "%s: Failed to map rx buffer, dropping packet.\n", dev->name); - lp->stats.rx_dropped++; - break; - } - - /* now we have a new skb to replace it, pass the used one up the stack */ - dma_unmap_single(lp->device, lp->rx_laddr[entry], SONIC_RBSIZE, DMA_FROM_DEVICE); - used_skb = lp->rx_skb[i]; - pkt_len = sonic_rda_get(dev, entry, SONIC_RD_PKTLEN); - skb_trim(used_skb, pkt_len); - used_skb->protocol = eth_type_trans(used_skb, dev); - netif_rx(used_skb); - lp->stats.rx_packets++; - lp->stats.rx_bytes += pkt_len; - - /* and insert the new skb */ - lp->rx_laddr[i] = new_laddr; - lp->rx_skb[i] = new_skb; - - bufadr_l = (unsigned long)new_laddr & 0xffff; - bufadr_h = (unsigned long)new_laddr >> 16; - sonic_rra_put(dev, i, SONIC_RR_BUFADR_L, bufadr_l); - sonic_rra_put(dev, i, SONIC_RR_BUFADR_H, bufadr_h); - /* - * this was the last packet out of the current receive buffer - * give the buffer back to the SONIC + /* If RBE is already asserted when RWP advances then + * it's safe to clear RBE after processing this packet. */ - lp->cur_rwp += SIZEOF_SONIC_RR * SONIC_BUS_SCALE(lp->dma_bitmode); - if (lp->cur_rwp >= lp->rra_end) lp->cur_rwp = lp->rra_laddr & 0xffff; - SONIC_WRITE(SONIC_RWP, lp->cur_rwp); - if (SONIC_READ(SONIC_ISR) & SONIC_INT_RBE) { - netif_dbg(lp, rx_err, dev, "%s: rx buffer exhausted\n", - __func__); - SONIC_WRITE(SONIC_ISR, SONIC_INT_RBE); /* clear the flag */ - } + rbe = rbe || SONIC_READ(SONIC_ISR) & SONIC_INT_RBE; + sonic_update_rra(dev, lp, addr, new_laddr); } /* * give back the descriptor @@ -527,6 +557,9 @@ static void sonic_rx(struct net_device * sonic_rda_get(dev, lp->eol_rx, SONIC_RD_LINK)); lp->eol_rx = prev_entry; } + + if (rbe) + SONIC_WRITE(SONIC_ISR, SONIC_INT_RBE); /* * If any worth-while packets have been received, netif_rx() * has done a mark_bh(NET_BH) for us and will work on them @@ -641,15 +674,10 @@ static int sonic_init(struct net_device } /* initialize all RRA registers */ - lp->rra_end = (lp->rra_laddr + SONIC_NUM_RRS * SIZEOF_SONIC_RR * - SONIC_BUS_SCALE(lp->dma_bitmode)) & 0xffff; - lp->cur_rwp = (lp->rra_laddr + (SONIC_NUM_RRS - 1) * SIZEOF_SONIC_RR * - SONIC_BUS_SCALE(lp->dma_bitmode)) & 0xffff; - - SONIC_WRITE(SONIC_RSA, lp->rra_laddr & 0xffff); - SONIC_WRITE(SONIC_REA, lp->rra_end); - SONIC_WRITE(SONIC_RRP, lp->rra_laddr & 0xffff); - SONIC_WRITE(SONIC_RWP, lp->cur_rwp); + SONIC_WRITE(SONIC_RSA, sonic_rr_addr(dev, 0)); + SONIC_WRITE(SONIC_REA, sonic_rr_addr(dev, SONIC_NUM_RRS)); + SONIC_WRITE(SONIC_RRP, sonic_rr_addr(dev, 0)); + SONIC_WRITE(SONIC_RWP, sonic_rr_addr(dev, SONIC_NUM_RRS - 1)); SONIC_WRITE(SONIC_URRA, lp->rra_laddr >> 16); SONIC_WRITE(SONIC_EOBC, (SONIC_RBSIZE >> 1) - (lp->dma_bitmode ? 2 : 1)); --- a/drivers/net/ethernet/natsemi/sonic.h +++ b/drivers/net/ethernet/natsemi/sonic.h @@ -314,8 +314,6 @@ struct sonic_local { u32 rda_laddr; /* logical DMA address of RDA */ dma_addr_t rx_laddr[SONIC_NUM_RRS]; /* logical DMA addresses of rx skbuffs */ dma_addr_t tx_laddr[SONIC_NUM_TDS]; /* logical DMA addresses of tx skbuffs */ - unsigned int rra_end; - unsigned int cur_rwp; unsigned int cur_rx; unsigned int cur_tx; /* first unacked transmit packet */ unsigned int eol_rx; @@ -450,6 +448,22 @@ static inline __u16 sonic_rra_get(struct (entry * SIZEOF_SONIC_RR) + offset); } +static inline u16 sonic_rr_addr(struct net_device *dev, int entry) +{ + struct sonic_local *lp = netdev_priv(dev); + + return lp->rra_laddr + + entry * SIZEOF_SONIC_RR * SONIC_BUS_SCALE(lp->dma_bitmode); +} + +static inline u16 sonic_rr_entry(struct net_device *dev, u16 addr) +{ + struct sonic_local *lp = netdev_priv(dev); + + return (addr - (u16)lp->rra_laddr) / (SIZEOF_SONIC_RR * + SONIC_BUS_SCALE(lp->dma_bitmode)); +} + static const char version[] = "sonic.c:v0.92 20.9.98 tsbogend@alpha.franken.de\n";