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 X-Spam-Level: X-Spam-Status: No, score=-17.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 DB7CEC4708F for ; Fri, 4 Jun 2021 10:15:00 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A492561404 for ; Fri, 4 Jun 2021 10:15:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A492561404 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=walle.cc Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=lPslwGAe8TKg7X9BHjzeVfP9o3Xygkue4CtpIOcDXF0=; b=FyLMy/wcLAv+EZ II3iadgP3lRlAxNQBvBK0txQSw08xRf9kEKO6ThcgHR02ECucDyo3pgf6dLiMI/VKBJbH922F0OAJ rbEk1kje6mXy8Sk1qVJN12KswVkWAMqKhUBOYiQ0GZgOumUgB91NIl/XHwNb9hUhioZDo58McR/Dw RZEbs2MK1ddJuuKO1WFR0NnxO6BfudPudFOcMxTUNaclToZABRlaXWTn8eielypT2bSH0ozVmUl6k tyk/U5rE1dDZIPU3xwxRwj8vYBJlUGOmn8dLFZDA2xVaPTFXFfjOqVUYe0kK2FKT3ywoPxUv7Y+hB 7eXRTLPHDuPrPij/88/Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1lp6qN-00CsJi-7K; Fri, 04 Jun 2021 10:14:23 +0000 Received: from ssl.serverraum.org ([176.9.125.105]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1lp6fU-00Cn03-W5 for linux-mtd@lists.infradead.org; Fri, 04 Jun 2021 10:03:13 +0000 Received: from mwalle01.fritz.box (ip4d17858c.dynamic.kabel-deutschland.de [77.23.133.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ssl.serverraum.org (Postfix) with ESMTPSA id DDBE12224F; Fri, 4 Jun 2021 12:03:03 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2016061301; t=1622800984; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Kt4yiaInnmJeaGkE/MPYgei4muQd1jn/4Uq7TKm1ceo=; b=s5gDsHN1cHhYbtdUp1fJxvZ6xKbFmmUlz6nIoBpG4a4LuzOuUUFWfJZB1SbXpzs+R//nsw uyejZ+Du9Z9x7sNLZzznvCJiPV3QFPo+3e6Bt232XIz3uMCqkwd+ZLRO5/13VcLZ/vGbYp sY5Va3n618gKwABX/PxjX8KVzHOOfDk= From: Michael Walle To: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Tudor Ambarus , Michael Walle , Pratyush Yadav , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra Subject: [PATCH v5 3/5] mtd: spi-nor: otp: return -EROFS if region is read-only Date: Fri, 4 Jun 2021 12:02:50 +0200 Message-Id: <20210604100252.9975-4-michael@walle.cc> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210604100252.9975-1-michael@walle.cc> References: <20210604100252.9975-1-michael@walle.cc> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210604_030309_257001_B123351E X-CRM114-Status: GOOD ( 19.37 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org SPI NOR flashes will just ignore program commands if the OTP region is locked. Thus, a user might not notice that the intended write didn't end up in the flash. Return -EROFS to the user in this case. From what I can tell, chips/cfi_cmdset_0001.c also return this error code. One could optimize spi_nor_mtd_otp_range_is_locked() to read the status register only once and not for every OTP region, but for that we would need some more invasive changes. Given that this is one-time-programmable memory and the normal access mode is reading, we just live with the small overhead. Fixes: 069089acf88b ("mtd: spi-nor: add OTP support") Signed-off-by: Michael Walle Reviewed-by: Pratyush Yadav --- drivers/mtd/spi-nor/otp.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/drivers/mtd/spi-nor/otp.c b/drivers/mtd/spi-nor/otp.c index 3898ed67ba1c..063f8fb68649 100644 --- a/drivers/mtd/spi-nor/otp.c +++ b/drivers/mtd/spi-nor/otp.c @@ -249,6 +249,32 @@ static int spi_nor_mtd_otp_info(struct mtd_info *mtd, size_t len, return ret; } +static int spi_nor_mtd_otp_range_is_locked(struct spi_nor *nor, loff_t ofs, + size_t len) +{ + const struct spi_nor_otp_ops *ops = nor->params->otp.ops; + unsigned int region; + int locked; + + if (!len) + return 0; + + /* + * If any of the affected OTP regions are locked the entire range is + * considered locked. + */ + for (region = spi_nor_otp_offset_to_region(nor, ofs); + region <= spi_nor_otp_offset_to_region(nor, ofs + len - 1); + region++) { + locked = ops->is_locked(nor, region); + /* take the branch it is locked or in case of an error */ + if (locked) + return locked; + } + + return 0; +} + static int spi_nor_mtd_otp_read_write(struct mtd_info *mtd, loff_t ofs, size_t total_len, size_t *retlen, const u8 *buf, bool is_write) @@ -271,6 +297,16 @@ static int spi_nor_mtd_otp_read_write(struct mtd_info *mtd, loff_t ofs, /* don't access beyond the end */ total_len = min_t(size_t, total_len, spi_nor_otp_size(nor) - ofs); + if (is_write) { + ret = spi_nor_mtd_otp_range_is_locked(nor, ofs, total_len); + if (ret < 0) { + goto out; + } else if (ret) { + ret = -EROFS; + goto out; + } + } + *retlen = 0; while (total_len) { /* -- 2.20.1 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/