From patchwork Tue Mar 23 07:39:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Manivannan Sadhasivam X-Patchwork-Id: 407021 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, USER_AGENT_GIT autolearn=ham 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 D95CDC433E1 for ; Tue, 23 Mar 2021 07:40:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9EF276191F for ; Tue, 23 Mar 2021 07:40:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229822AbhCWHk0 (ORCPT ); Tue, 23 Mar 2021 03:40:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44984 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229893AbhCWHjy (ORCPT ); Tue, 23 Mar 2021 03:39:54 -0400 Received: from mail-pf1-x42e.google.com (mail-pf1-x42e.google.com [IPv6:2607:f8b0:4864:20::42e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6E147C061763 for ; Tue, 23 Mar 2021 00:39:54 -0700 (PDT) Received: by mail-pf1-x42e.google.com with SMTP id x126so13415185pfc.13 for ; Tue, 23 Mar 2021 00:39:54 -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=w0Dc7Z/1PtflixS4YTRrVIJxz0ZJpUsSszIaqgAgIVA=; b=lwmY830nLJA1dh8DShHTwjPkSTpzKl4JNN7tg5BiJuKgxinIEwG1emUGKqyPfgCejn Fqn50ums5A34ge7Pr5cDJVFrpnrDu4Q6ZRps/Wf7Axi4fXvaPv7JHTFeRVtJdeOS/fGw TF5qktJ66QF/tkw05I3xaNyj3molQe0Ar3yes38cSiSMR1+uC9FUVsoxL3K/Bqfx4jfh iQ+zn1CiSV1GuOWL33FGLXDQQQqpwVRbaUP7ZXqBSHa044hqCR08nfTsZC4LfrOb6i0R +C6u7bSDCxk5b9meOfOVaZF7xBrQgDx2I6O/53pgCOiJAcMfEJdZ74dj0PFxdrWA8GZv FISQ== 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=w0Dc7Z/1PtflixS4YTRrVIJxz0ZJpUsSszIaqgAgIVA=; b=IjFi4iHkemMal1I3/Rm95RpxvR23kznc/fxCkQsWE9RnTbyj2V9wzsb5gv6PfLi/JX 0O6RgBIOudoXZRYmSM9B1bbgrjQzRi7gW2lgWWoQBniPMWFOXMnUig3dyC+l1H+c7ukP OTZIcr8YfU0lG6lSxtPg7J0rm7PYWwmGlEMB3TXZQ2r3KUTh7IyprG5KtiF3DLoT3oyr h/MlxFG+Wxype9ogGum20CD6tea9Rc87ux7YEHVL189fxwLbTPXlF+FkF7p9tIv6+fPu YLtef33JFbC7D35W7H7IhZ4Z9mOElUubtUPbfPjo6lxs1xnkbzuU5eZ7bcCV+z2FbRIJ DH7A== X-Gm-Message-State: AOAM533RynypXGDGDbr/836TUN0a9Nc4MusRQyrcZXwhsN0Si+PGqW6O YE1Ia9jLZsM5KhM+e9H0dDTv X-Google-Smtp-Source: ABdhPJyAl0oPGwTfWG55wWy4r1+xQQPT6r4e7BxJn8AclWa7ujLc9c+G/fgXfg5SD5zmDrgixdt9Iw== X-Received: by 2002:a05:6a00:1484:b029:214:23e5:a4f3 with SMTP id v4-20020a056a001484b029021423e5a4f3mr3740285pfu.26.1616485193873; Tue, 23 Mar 2021 00:39:53 -0700 (PDT) Received: from localhost.localdomain ([103.77.37.149]) by smtp.gmail.com with ESMTPSA id fs9sm1587465pjb.40.2021.03.23.00.39.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Mar 2021 00:39:53 -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 v8 3/3] mtd: rawnand: Add support for secure regions in NAND memory Date: Tue, 23 Mar 2021 13:09:30 +0530 Message-Id: <20210323073930.89754-4-manivannan.sadhasivam@linaro.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210323073930.89754-1-manivannan.sadhasivam@linaro.org> References: <20210323073930.89754-1-manivannan.sadhasivam@linaro.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@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 | 105 +++++++++++++++++++++++++++++++ include/linux/mtd/rawnand.h | 14 +++++ 2 files changed, 119 insertions(+) diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c index c33fa1b1847f..2a990219f498 100644 --- a/drivers/mtd/nand/raw/nand_base.c +++ b/drivers/mtd/nand/raw/nand_base.c @@ -278,11 +278,46 @@ 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, u64 size) +{ + int i; + + /* Skip touching the secure regions if present */ + for (i = 0; i < chip->nr_secure_regions; i++) { + const struct nand_secure_region *region = &chip->secure_regions[i]; + + if (offset + size < region->offset || + offset >= region->offset + region->size) + continue; + + 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 +432,11 @@ 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 +605,11 @@ 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); } @@ -3127,6 +3172,11 @@ 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 +3508,11 @@ 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); @@ -3979,6 +4034,11 @@ 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 +4240,11 @@ 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, instr->len); + if (ret) + return ret; + /* Grab the lock and see if the device is available */ ret = nand_get_device(chip); if (ret) @@ -4995,10 +5060,37 @@ 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, i, j; + + 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; + + for (i = 0, j = 0; i < chip->nr_secure_regions; i++, j += 2) { + of_property_read_u64_index(dn, "secure-regions", j, + &chip->secure_regions[i].offset); + of_property_read_u64_index(dn, "secure-regions", j + 1, + &chip->secure_regions[i].size); + } + } + + 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 +5107,16 @@ 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 +6170,9 @@ 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..17ddc900a1dc 100644 --- a/include/linux/mtd/rawnand.h +++ b/include/linux/mtd/rawnand.h @@ -1036,6 +1036,16 @@ struct nand_manufacturer { void *priv; }; +/** + * struct nand_secure_region - NAND secure region structure + * @offset: Offset of the start of the secure region + * @size: Size of the secure region + */ +struct nand_secure_region { + u64 offset; + u64 size; +}; + /** * struct nand_chip - NAND Private Flash Chip Data * @base: Inherit from the generic NAND device @@ -1086,6 +1096,8 @@ 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: Structure containing the secure regions info + * @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 +1147,8 @@ struct nand_chip { unsigned int suspended : 1; int cur_cs; int read_retries; + struct nand_secure_region *secure_regions; + u8 nr_secure_regions; /* Externals */ struct nand_controller *controller;