From mboxrd@z Thu Jan 1 00:00:00 1970 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 ECA3CC433EF for ; Mon, 11 Jul 2022 09:41:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233199AbiGKJls (ORCPT ); Mon, 11 Jul 2022 05:41:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37632 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233289AbiGKJk5 (ORCPT ); Mon, 11 Jul 2022 05:40:57 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B458B904D4; Mon, 11 Jul 2022 02:20:54 -0700 (PDT) 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 E861161227; Mon, 11 Jul 2022 09:20:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 08352C34115; Mon, 11 Jul 2022 09:20:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1657531253; bh=Vymnmh1NdcpbekCmXewv0IKJXbg8zm4/a6uY9d1SZwI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jZOtD/uiR0N0Z76Kv7LNkwtJdLOBxuRcs8pYgZMOe03zbTYc2MvP2zCbPMaFMfEJ4 sniVomjjgzeA8xOuEy6AZfM9m5Q1FE2aUdt05GyoV77mvE3wd6rRaFjqGggXjjspcG hwvuvDGCn/hg5LdHXb1lnkgJxS/TbrMBAULGqL9o= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andrew Gabbasov , Krzysztof Kozlowski , Sasha Levin Subject: [PATCH 5.15 037/230] memory: renesas-rpc-if: Avoid unaligned bus access for HyperFlash Date: Mon, 11 Jul 2022 11:04:53 +0200 Message-Id: <20220711090605.133661300@linuxfoundation.org> X-Mailer: git-send-email 2.37.0 In-Reply-To: <20220711090604.055883544@linuxfoundation.org> References: <20220711090604.055883544@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andrew Gabbasov [ Upstream commit 1869023e24c0de73a160a424dac4621cefd628ae ] HyperFlash devices in Renesas SoCs use 2-bytes addressing, according to HW manual paragraph 62.3.3 (which officially describes Serial Flash access, but seems to be applicable to HyperFlash too). And 1-byte bus read operations to 2-bytes unaligned addresses in external address space read mode work incorrectly (returns the other byte from the same word). Function memcpy_fromio(), used by the driver to read data from the bus, in ARM64 architecture (to which Renesas cores belong) uses 8-bytes bus accesses for appropriate aligned addresses, and 1-bytes accesses for other addresses. This results in incorrect data read from HyperFlash in unaligned cases. This issue can be reproduced using something like the following commands (where mtd1 is a parition on Hyperflash storage, defined properly in a device tree): [Correct fragment, read from Hyperflash] root@rcar-gen3:~# dd if=/dev/mtd1 of=/tmp/zz bs=32 count=1 root@rcar-gen3:~# hexdump -C /tmp/zz 00000000 f4 03 00 aa f5 03 01 aa f6 03 02 aa f7 03 03 aa |................| 00000010 00 00 80 d2 40 20 18 d5 00 06 81 d2 a0 18 a6 f2 |....@ ..........| 00000020 [Incorrect read of the same fragment: see the difference at offsets 8-11] root@rcar-gen3:~# dd if=/dev/mtd1 of=/tmp/zz bs=12 count=1 root@rcar-gen3:~# hexdump -C /tmp/zz 00000000 f4 03 00 aa f5 03 01 aa 03 03 aa aa |............| 0000000c Fix this issue by creating a local replacement of the copying function, that performs only properly aligned bus accesses, and is used for reading from HyperFlash. Fixes: ca7d8b980b67f ("memory: add Renesas RPC-IF driver") Cc: Signed-off-by: Andrew Gabbasov Link: https://lore.kernel.org/r/20210922184830.29147-1-andrew_gabbasov@mentor.com Signed-off-by: Krzysztof Kozlowski Signed-off-by: Sasha Levin --- drivers/memory/renesas-rpc-if.c | 48 +++++++++++++++++++++++++++++++-- 1 file changed, 46 insertions(+), 2 deletions(-) diff --git a/drivers/memory/renesas-rpc-if.c b/drivers/memory/renesas-rpc-if.c index 3a416705f61c..c77b23b68a93 100644 --- a/drivers/memory/renesas-rpc-if.c +++ b/drivers/memory/renesas-rpc-if.c @@ -199,7 +199,6 @@ static int rpcif_reg_read(void *context, unsigned int reg, unsigned int *val) *val = readl(rpc->base + reg); return 0; - } static int rpcif_reg_write(void *context, unsigned int reg, unsigned int val) @@ -577,6 +576,48 @@ int rpcif_manual_xfer(struct rpcif *rpc) } EXPORT_SYMBOL(rpcif_manual_xfer); +static void memcpy_fromio_readw(void *to, + const void __iomem *from, + size_t count) +{ + const int maxw = (IS_ENABLED(CONFIG_64BIT)) ? 8 : 4; + u8 buf[2]; + + if (count && ((unsigned long)from & 1)) { + *(u16 *)buf = __raw_readw((void __iomem *)((unsigned long)from & ~1)); + *(u8 *)to = buf[1]; + from++; + to++; + count--; + } + while (count >= 2 && !IS_ALIGNED((unsigned long)from, maxw)) { + *(u16 *)to = __raw_readw(from); + from += 2; + to += 2; + count -= 2; + } + while (count >= maxw) { +#ifdef CONFIG_64BIT + *(u64 *)to = __raw_readq(from); +#else + *(u32 *)to = __raw_readl(from); +#endif + from += maxw; + to += maxw; + count -= maxw; + } + while (count >= 2) { + *(u16 *)to = __raw_readw(from); + from += 2; + to += 2; + count -= 2; + } + if (count) { + *(u16 *)buf = __raw_readw(from); + *(u8 *)to = buf[0]; + } +} + ssize_t rpcif_dirmap_read(struct rpcif *rpc, u64 offs, size_t len, void *buf) { loff_t from = offs & (RPCIF_DIRMAP_SIZE - 1); @@ -598,7 +639,10 @@ ssize_t rpcif_dirmap_read(struct rpcif *rpc, u64 offs, size_t len, void *buf) regmap_write(rpc->regmap, RPCIF_DRDMCR, rpc->dummy); regmap_write(rpc->regmap, RPCIF_DRDRENR, rpc->ddr); - memcpy_fromio(buf, rpc->dirmap + from, len); + if (rpc->bus_size == 2) + memcpy_fromio_readw(buf, rpc->dirmap + from, len); + else + memcpy_fromio(buf, rpc->dirmap + from, len); pm_runtime_put(rpc->dev); -- 2.35.1