From patchwork Thu Apr 1 15:15:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Manivannan Sadhasivam X-Patchwork-Id: 413843 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,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 9A02DC001B8 for ; Thu, 1 Apr 2021 17:42:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 72374613CE for ; Thu, 1 Apr 2021 17:42:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235347AbhDARmj (ORCPT ); Thu, 1 Apr 2021 13:42:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234355AbhDARg7 (ORCPT ); Thu, 1 Apr 2021 13:36:59 -0400 Received: from mail-pl1-x62f.google.com (mail-pl1-x62f.google.com [IPv6:2607:f8b0:4864:20::62f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E7D37C00F7FF for ; Thu, 1 Apr 2021 08:15:35 -0700 (PDT) Received: by mail-pl1-x62f.google.com with SMTP id h8so1173507plt.7 for ; Thu, 01 Apr 2021 08:15:35 -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=v+aoqp7/hh2ZJdg8Bt5Hf7dmndB59spkh4lB3mp0E74=; b=kGBK/r8CKBxUNprCLJ6ee9nOvbOqWpDSdZJUuszXHKcioB/BkSJAcMMc8wbwiBeQxg EYkP3PZT1RxY88LvRMhINgnkjtqMCFCPwWZdbe7ndIVaihFMZYNBkJBnvCGyob94oQud iNf7QlgVJgbXhj1el6Rlsm/nAlXZpyLhiSWfnFMCSFg/SoNZZc8mGvxvB4RFNDprXC73 QuxrFsIKqb7uxLo/MgrWkrf3whDIrg8LmKPYhyZRGs3QVPGROa/qxdpFzDY0LDPM7i5A K/2D9YX8AhClTgoTUKXaMRJyMv2Spq53DRBW0txjxp2rEnnywWOgoReioJW49t5AKzMC yiEw== 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=v+aoqp7/hh2ZJdg8Bt5Hf7dmndB59spkh4lB3mp0E74=; b=Yd4k5g2Ilh/puhzHSb+TsbupCLVOEez6Yf1dQ6EaLYG8lFDoKrdWcgNI+n4U/WOCIW QkOx9sMY92GI9w2PKWlhQLcNzaWrbysdi1xExftWcaM6ftfOavLHgymM+xGceR+cpcro lYT/ZgHBeCJpNH8L1sdqyY0vWGCSbAnQ5Y2l1YQ/cMoKg22TweU7u2J0FOlqbW6YQ9P7 PZnPF23IwdYCF4rcncZDekj6KvPT0IXH7hZxlxFw1dVwjcL46BKq8cqIehVM/S4mwcCA P2EiVQ7hJsTutUa9RJIG9rJcu59g9FFha9ilbHD7x5n1Rf+fyi93xxmboQCvryuNXvfo h1cg== X-Gm-Message-State: AOAM533SmKIKOGBOJI7ft9nakVknKsf84XpqhIzjOs0MEKBrRhOHj5Zb E7uxXu5RQ48F3moVTlJoc+Y3 X-Google-Smtp-Source: ABdhPJyLl09ogfVFgj/40f2XOlVbEF3wsCwgBy9MwM0lPlcS8zD1vWvy+BWlPcZDVcEBOZFpehentQ== X-Received: by 2002:a17:903:2490:b029:e6:faf5:86df with SMTP id p16-20020a1709032490b02900e6faf586dfmr8239479plw.69.1617290135384; Thu, 01 Apr 2021 08:15:35 -0700 (PDT) Received: from localhost.localdomain ([103.77.37.138]) by smtp.gmail.com with ESMTPSA id 35sm5652769pgr.14.2021.04.01.08.15.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 01 Apr 2021 08:15:35 -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 v9 3/4] mtd: rawnand: Add support for secure regions in NAND memory Date: Thu, 1 Apr 2021 20:45:07 +0530 Message-Id: <20210401151508.143075-4-manivannan.sadhasivam@linaro.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210401151508.143075-1-manivannan.sadhasivam@linaro.org> References: <20210401151508.143075-1-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 | 107 ++++++++++++++++++++++++++++++- include/linux/mtd/rawnand.h | 14 ++++ 2 files changed, 120 insertions(+), 1 deletion(-) diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c index c33fa1b1847f..c216d3eca915 100644 --- a/drivers/mtd/nand/raw/nand_base.c +++ b/drivers/mtd/nand/raw/nand_base.c @@ -278,11 +278,50 @@ static int nand_block_bad(struct nand_chip *chip, loff_t ofs) return 0; } +/** + * nand_region_is_secured() - 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 true if the region is + * secured else false. + */ +static bool nand_region_is_secured(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; + + pr_debug("%s: Region 0x%llx - 0x%llx is secured!", + __func__, offset, offset + size); + + return true; + } + + return false; +} + static int nand_isbad_bbm(struct nand_chip *chip, loff_t ofs) { + struct mtd_info *mtd = nand_to_mtd(chip); + int last_page = ((mtd->erasesize - mtd->writesize) >> + chip->page_shift) & chip->pagemask; + if (chip->options & NAND_NO_BBM_QUIRK) return 0; + /* Check if the region is secured */ + if (nand_region_is_secured(chip, ofs, last_page)) + return -EIO; + if (chip->legacy.block_bad) return chip->legacy.block_bad(chip, ofs); @@ -397,6 +436,10 @@ static int nand_do_write_oob(struct nand_chip *chip, loff_t to, return -EINVAL; } + /* Check if the region is secured */ + if (nand_region_is_secured(chip, to, ops->ooblen)) + return -EIO; + chipnr = (int)(to >> chip->chip_shift); /* @@ -565,6 +608,11 @@ 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_region_is_secured(chip, ofs, 0)) + return -EIO; + /* Return info from the table */ return nand_isreserved_bbt(chip, ofs); } @@ -3127,6 +3175,10 @@ 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 */ + if (nand_region_is_secured(chip, from, readlen)) + return -EIO; + chipnr = (int)(from >> chip->chip_shift); nand_select_target(chip, chipnr); @@ -3458,6 +3510,10 @@ 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 */ + if (nand_region_is_secured(chip, from, readlen)) + return -EIO; + stats = mtd->ecc_stats; len = mtd_oobavail(mtd, ops); @@ -3979,6 +4035,10 @@ static int nand_do_write_ops(struct nand_chip *chip, loff_t to, return -EINVAL; } + /* Check if the region is secured */ + if (nand_region_is_secured(chip, to, writelen)) + return -EIO; + column = to & (mtd->writesize - 1); chipnr = (int)(to >> chip->chip_shift); @@ -4180,6 +4240,10 @@ 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 */ + if (nand_region_is_secured(chip, instr->addr, instr->len)) + return -EIO; + /* Grab the lock and see if the device is available */ ret = nand_get_device(chip); if (ret) @@ -4995,6 +5059,31 @@ 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); + int nr_elem, i, j; + + nr_elem = of_property_count_elems_of_size(dn, "secure-regions", sizeof(u64)); + if (!nr_elem) + return 0; + + chip->nr_secure_regions = nr_elem / 2; + chip->secure_regions = kcalloc(chip->nr_secure_regions, 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)); @@ -5953,6 +6042,16 @@ static int nand_scan_tail(struct nand_chip *chip) goto err_free_interface_config; } + /* + * 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) + goto err_free_interface_config; + /* Check, if we should skip the bad block table scan */ if (chip->options & NAND_SKIP_BBTSCAN) return 0; @@ -5960,10 +6059,13 @@ static int nand_scan_tail(struct nand_chip *chip) /* Build bad block table */ ret = nand_create_bbt(chip); if (ret) - goto err_free_interface_config; + goto err_free_secure_regions; return 0; +err_free_secure_regions: + kfree(chip->secure_regions); + err_free_interface_config: kfree(chip->best_interface_config); @@ -6051,6 +6153,9 @@ void nand_cleanup(struct nand_chip *chip) nanddev_cleanup(&chip->base); + /* Free secure regions data */ + kfree(chip->secure_regions); + /* Free bad block table memory */ kfree(chip->bbt); kfree(chip->data_buf); 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;