From patchwork Thu Mar 18 12:43:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Manivannan Sadhasivam X-Patchwork-Id: 404166 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, 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 2AA94C4332B for ; Thu, 18 Mar 2021 12:44:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9913B64F91 for ; Thu, 18 Mar 2021 12:44:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230398AbhCRMoZ (ORCPT ); Thu, 18 Mar 2021 08:44:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59982 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230506AbhCRMoL (ORCPT ); Thu, 18 Mar 2021 08:44:11 -0400 Received: from mail-pj1-x102e.google.com (mail-pj1-x102e.google.com [IPv6:2607:f8b0:4864:20::102e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6F3AAC06175F for ; Thu, 18 Mar 2021 05:44:11 -0700 (PDT) Received: by mail-pj1-x102e.google.com with SMTP id nh23-20020a17090b3657b02900c0d5e235a8so3093232pjb.0 for ; Thu, 18 Mar 2021 05:44:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=IhGMHYMmcLeKrhiSxz8FXTAntRfx6etYiml4bVTAZK8=; b=LOtn5eEwtiV1zaBqABmHp/3o1br1Eel9swgd8xNI1ysAHBsMY2zvKSF7Hm9l4l/hK7 U79gOvfgg6lIk0jRbzuMvnFl8i1Zm42INDUU6FzRdWDbuEO5rBrRyRPV23BH43GaqRb4 ZgQ2pGobh7yCHThN0NaRRTL3KmMF3nQbJH3Itd5Q/zLnHlEw0DQzjsGcP/BS1EGV584A B87SptBeZRmqHhWi3zwV/0JAflz8ZATwVw9lYdM7kijZVrqolqlbMSbJ43/Dfxz2k13c ba6f1gNS+na89goRriUQfAyMQEQd5rtlQvvHMFzPl0XnlirVFxvgEcF4jo8cGkC4PrS6 RTTg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=IhGMHYMmcLeKrhiSxz8FXTAntRfx6etYiml4bVTAZK8=; b=Pg4DJu58blfkY/TM4he82jzTOVRT9bGJXMISXbTHxyvZFrLfX0HTOIzjEquq1+kO9n SUyzB1XRF8oG4l+T9RCDMdwc9Frgvry5sTxD1kM9JonQMPOUc5Sbd5QBbUyFPFHHi3TM ct15Vi8sNo58dR3ldBaBqVRdipWZig/6qGu9lNHN7JDvnxnE9axwilcNdo2RKy5CPyen hxzSfrb/GdGOjQOnNRgL3mFQ2TFAY7h2MSyMaXvmIVtN1Z8e8y/+Ke7j3wWkTet9t5q9 S98DbKxqCVyrbYZi16gnETzb8gCXhlbEV9MWimiDptya/rQhCEQLJv4apQNR7ZQVD/+p 2t3Q== X-Gm-Message-State: AOAM532cj+fZvnDCYnPV/gvgpI0ho1adZhtd1hlSGyUth4EbGkRfHt/6 yx4JXpAF/TaH+J38Lv0wDdgS X-Google-Smtp-Source: ABdhPJwWhLMWXwHQwJGmwyBr6XF2pjRjpgL8zsWEsHhNHtdq0K6wt4IxAeCAX7CbjTS9j6lwXuKlPg== X-Received: by 2002:a17:90b:344c:: with SMTP id lj12mr4347160pjb.208.1616071450780; Thu, 18 Mar 2021 05:44:10 -0700 (PDT) Received: from localhost.localdomain ([2409:4072:6d00:4737:af26:182c:a57e:1d9e]) by smtp.gmail.com with ESMTPSA id w84sm2530694pfc.142.2021.03.18.05.44.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 18 Mar 2021 05:44:10 -0700 (PDT) From: Manivannan Sadhasivam To: miquel.raynal@bootlin.com, richard@nod.at, vigneshr@ti.com, robh+dt@kernel.org Cc: linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, boris.brezillon@collabora.com, Daniele.Palmas@telit.com, bjorn.andersson@linaro.org, Manivannan Sadhasivam Subject: [PATCH v6 3/3] mtd: rawnand: Add support for secure regions in NAND memory Date: Thu, 18 Mar 2021 18:13:42 +0530 Message-Id: <20210318124342.32745-4-manivannan.sadhasivam@linaro.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210318124342.32745-1-manivannan.sadhasivam@linaro.org> References: <20210318124342.32745-1-manivannan.sadhasivam@linaro.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On a typical end product, a vendor may choose to secure some regions in the NAND memory which are supposed to stay intact between FW upgrades. The access to those regions will be blocked by a secure element like Trustzone. So the normal world software like Linux kernel should not touch these regions (including reading). The regions are declared using a NAND chip DT property, "secure-regions". So let's make use of this property in the raw NAND core and skip access to the secure regions present in a system. Signed-off-by: Manivannan Sadhasivam --- drivers/mtd/nand/raw/nand_base.c | 111 +++++++++++++++++++++++++++++++ include/linux/mtd/rawnand.h | 4 ++ 2 files changed, 115 insertions(+) diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c index c33fa1b1847f..d2958549ba46 100644 --- a/drivers/mtd/nand/raw/nand_base.c +++ b/drivers/mtd/nand/raw/nand_base.c @@ -278,11 +278,47 @@ static int nand_block_bad(struct nand_chip *chip, loff_t ofs) return 0; } +/** + * nand_check_secure_region() - Check if the region is secured + * @chip: NAND chip object + * @offset: Offset of the region to check + * @size: Size of the region to check + * + * Checks if the region is secured by comparing the offset and size with the + * list of secure regions obtained from DT. Returns -EIO if the region is + * secured else 0. + */ +static int nand_check_secure_region(struct nand_chip *chip, loff_t offset, u32 size) +{ + int i, j; + + /* Skip touching the secure regions if present */ + for (i = 0, j = 0; i < chip->nr_secure_regions; i++, j += 2) { + /* First compare the start offset */ + if (offset >= chip->secure_regions[j] && + (offset < chip->secure_regions[j] + chip->secure_regions[j + 1])) + return -EIO; + /* ...then offset + size */ + else if (offset < chip->secure_regions[i] && + (offset + size) >= chip->secure_regions[i]) + return -EIO; + } + + return 0; +} + static int nand_isbad_bbm(struct nand_chip *chip, loff_t ofs) { + int ret; + if (chip->options & NAND_NO_BBM_QUIRK) return 0; + /* Check if the region is secured */ + ret = nand_check_secure_region(chip, ofs, 0); + if (ret) + return ret; + if (chip->legacy.block_bad) return chip->legacy.block_bad(chip, ofs); @@ -397,6 +433,11 @@ static int nand_do_write_oob(struct nand_chip *chip, loff_t to, return -EINVAL; } + /* Check if the region is secured */ + ret = nand_check_secure_region(chip, to, ops->ooblen); + if (ret) + return ret; + chipnr = (int)(to >> chip->chip_shift); /* @@ -565,6 +606,11 @@ static int nand_block_isreserved(struct mtd_info *mtd, loff_t ofs) if (!chip->bbt) return 0; + + /* Check if the region is secured */ + if (nand_check_secure_region(chip, ofs, 0)) + return -EIO; + /* Return info from the table */ return nand_isreserved_bbt(chip, ofs); } @@ -2737,6 +2783,11 @@ static int nand_read_page_swecc(struct nand_chip *chip, uint8_t *buf, uint8_t *ecc_code = chip->ecc.code_buf; unsigned int max_bitflips = 0; + /* Check if the region is secured */ + ret = nand_check_secure_region(chip, ((loff_t)page << chip->page_shift), 0); + if (ret) + return ret; + chip->ecc.read_page_raw(chip, buf, 1, page); for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) @@ -3127,6 +3178,11 @@ static int nand_do_read_ops(struct nand_chip *chip, loff_t from, int retry_mode = 0; bool ecc_fail = false; + /* Check if the region is secured */ + ret = nand_check_secure_region(chip, from, readlen); + if (ret) + return ret; + chipnr = (int)(from >> chip->chip_shift); nand_select_target(chip, chipnr); @@ -3458,6 +3514,11 @@ static int nand_do_read_oob(struct nand_chip *chip, loff_t from, pr_debug("%s: from = 0x%08Lx, len = %i\n", __func__, (unsigned long long)from, readlen); + /* Check if the region is secured */ + ret = nand_check_secure_region(chip, from, readlen); + if (ret) + return ret; + stats = mtd->ecc_stats; len = mtd_oobavail(mtd, ops); @@ -3709,6 +3770,11 @@ static int nand_write_page_swecc(struct nand_chip *chip, const uint8_t *buf, uint8_t *ecc_calc = chip->ecc.calc_buf; const uint8_t *p = buf; + /* Check if the region is secured */ + ret = nand_check_secure_region(chip, ((loff_t)page << chip->page_shift), 0); + if (ret) + return ret; + /* Software ECC calculation */ for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) chip->ecc.calculate(chip, p, &ecc_calc[i]); @@ -3979,6 +4045,11 @@ static int nand_do_write_ops(struct nand_chip *chip, loff_t to, return -EINVAL; } + /* Check if the region is secured */ + ret = nand_check_secure_region(chip, to, writelen); + if (ret) + return ret; + column = to & (mtd->writesize - 1); chipnr = (int)(to >> chip->chip_shift); @@ -4180,6 +4251,11 @@ int nand_erase_nand(struct nand_chip *chip, struct erase_info *instr, if (check_offs_len(chip, instr->addr, instr->len)) return -EINVAL; + /* Check if the region is secured */ + ret = nand_check_secure_region(chip, instr->addr, len); + if (ret) + return ret; + /* Grab the lock and see if the device is available */ ret = nand_get_device(chip); if (ret) @@ -4995,10 +5071,32 @@ static bool of_get_nand_on_flash_bbt(struct device_node *np) return of_property_read_bool(np, "nand-on-flash-bbt"); } +static int of_get_nand_secure_regions(struct nand_chip *chip) +{ + struct device_node *dn = nand_get_flash_node(chip); + struct property *prop; + int length, nr_elem; + + prop = of_find_property(dn, "secure-regions", &length); + if (prop) { + nr_elem = length / sizeof(u64); + chip->nr_secure_regions = nr_elem / 2; + + chip->secure_regions = kcalloc(nr_elem, sizeof(*chip->secure_regions), GFP_KERNEL); + if (!chip->secure_regions) + return -ENOMEM; + + of_property_read_u64_array(dn, "secure-regions", chip->secure_regions, nr_elem); + } + + return 0; +} + static int rawnand_dt_init(struct nand_chip *chip) { struct nand_device *nand = mtd_to_nanddev(nand_to_mtd(chip)); struct device_node *dn = nand_get_flash_node(chip); + int ret; if (!dn) return 0; @@ -5015,6 +5113,16 @@ static int rawnand_dt_init(struct nand_chip *chip) of_get_nand_ecc_user_config(nand); of_get_nand_ecc_legacy_user_config(chip); + /* + * Look for secure regions in the NAND chip. These regions are supposed + * to be protected by a secure element like Trustzone. So the read/write + * accesses to these regions will be blocked in the runtime by this + * driver. + */ + ret = of_get_nand_secure_regions(chip); + if (!ret) + return ret; + /* * If neither the user nor the NAND controller have requested a specific * ECC engine type, we will default to NAND_ECC_ENGINE_TYPE_ON_HOST. @@ -6068,6 +6176,9 @@ void nand_cleanup(struct nand_chip *chip) /* Free manufacturer priv data. */ nand_manufacturer_cleanup(chip); + /* Free secure regions data */ + kfree(chip->secure_regions); + /* Free controller specific allocations after chip identification */ nand_detach(chip); diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h index 6b3240e44310..d385c4fe8b0f 100644 --- a/include/linux/mtd/rawnand.h +++ b/include/linux/mtd/rawnand.h @@ -1086,6 +1086,8 @@ struct nand_manufacturer { * NAND Controller drivers should not modify this value, but they're * allowed to read it. * @read_retries: The number of read retry modes supported + * @secure_regions: Array representing the secure regions + * @nr_secure_regions: Number of secure regions * @controller: The hardware controller structure which is shared among multiple * independent devices * @ecc: The ECC controller structure @@ -1135,6 +1137,8 @@ struct nand_chip { unsigned int suspended : 1; int cur_cs; int read_retries; + u64 *secure_regions; + u8 nr_secure_regions; /* Externals */ struct nand_controller *controller;