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=-9.5 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 7071DC2BB85 for ; Tue, 7 Apr 2020 16:21:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 41307206C0 for ; Tue, 7 Apr 2020 16:21:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728215AbgDGQVb (ORCPT ); Tue, 7 Apr 2020 12:21:31 -0400 Received: from 212.199.177.27.static.012.net.il ([212.199.177.27]:40605 "EHLO herzl.nuvoton.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728121AbgDGQV1 (ORCPT ); Tue, 7 Apr 2020 12:21:27 -0400 Received: from taln60.nuvoton.co.il (ntil-fw [212.199.177.25]) by herzl.nuvoton.co.il (8.13.8/8.13.8) with ESMTP id 037GKrVl002262; Tue, 7 Apr 2020 19:20:53 +0300 Received: by taln60.nuvoton.co.il (Postfix, from userid 10140) id 7E9F3639B2; Tue, 7 Apr 2020 19:20:53 +0300 (IDT) From: amirmizi6@gmail.com To: Eyal.Cohen@nuvoton.com, jarkko.sakkinen@linux.intel.com, oshrialkoby85@gmail.com, alexander.steffen@infineon.com, robh+dt@kernel.org, mark.rutland@arm.com, peterhuewe@gmx.de, jgg@ziepe.ca, arnd@arndb.de, gregkh@linuxfoundation.org Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-integrity@vger.kernel.org, oshri.alkoby@nuvoton.com, tmaimon77@gmail.com, gcwilson@us.ibm.com, kgoldman@us.ibm.com, Dan.Morav@nuvoton.com, oren.tanami@nuvoton.com, shmulik.hager@nuvoton.com, amir.mizinski@nuvoton.com, Amir Mizinski , Christophe Ricard Subject: [PATCH v6 2/7] tpm: tpm_tis: Add check_data handle to tpm_tis_phy_ops Date: Tue, 7 Apr 2020 19:20:39 +0300 Message-Id: <20200407162044.168890-3-amirmizi6@gmail.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20200407162044.168890-1-amirmizi6@gmail.com> References: <20200407162044.168890-1-amirmizi6@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Amir Mizinski In order to validate data integrity we need to compute the crc over the data sent in lower layer (I2C for instance). To do that tpm_tis_check_data() calls a "check_data" operation (if available). If data integrity check fails, a retry to save the sent/received data is implemented in tpm_tis_send_main()/tpm_tis_recv() functions. Considering this commit, the following steps are done when sending a command: 1. Host writes to TPM_STS.commandReady. 2. Host writes command. 3. Host checks that TPM received data is valid. 4. If data is currupted go to step 1. When receiving data: 1. Host checks that TPM_STS.dataAvail is set. 2. Host saves received data. 3. Host checks that received data is correct. 4. If data is currupted Host writes to TPM_STS.responseRetry and go to step 1. Co-developed-by: Christophe Ricard Signed-off-by: Christophe Ricard Signed-off-by: Amir Mizinski --- drivers/char/tpm/tpm_tis_core.c | 102 +++++++++++++++++++++++++--------------- drivers/char/tpm/tpm_tis_core.h | 3 ++ 2 files changed, 67 insertions(+), 38 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index 27c6ca0..6c4f232 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -242,6 +242,15 @@ static u8 tpm_tis_status(struct tpm_chip *chip) return status; } +static bool tpm_tis_check_data(struct tpm_chip *chip, const u8 *buf, size_t len) +{ + struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); + + if (priv->phy_ops->check_data) + return priv->phy_ops->check_data(priv, buf, len); + return true; +} + static void tpm_tis_ready(struct tpm_chip *chip) { struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); @@ -308,47 +317,59 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count) { struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); int size = 0; - int status; + int status, i; u32 expected; + bool check_data = false; - if (count < TPM_HEADER_SIZE) { - size = -EIO; - goto out; - } + for (i = 0; i < TPM_RETRY; i++) { + if (count < TPM_HEADER_SIZE) { + size = -EIO; + goto out; + } - size = recv_data(chip, buf, TPM_HEADER_SIZE); - /* read first 10 bytes, including tag, paramsize, and result */ - if (size < TPM_HEADER_SIZE) { - dev_err(&chip->dev, "Unable to read header\n"); - goto out; - } + size = recv_data(chip, buf, TPM_HEADER_SIZE); + /* read first 10 bytes, including tag, paramsize, and result */ + if (size < TPM_HEADER_SIZE) { + dev_err(&chip->dev, "Unable to read header\n"); + goto out; + } - expected = be32_to_cpu(*(__be32 *) (buf + 2)); - if (expected > count || expected < TPM_HEADER_SIZE) { - size = -EIO; - goto out; - } + expected = be32_to_cpu(*(__be32 *) (buf + 2)); + if (expected > count || expected < TPM_HEADER_SIZE) { + size = -EIO; + goto out; + } - size += recv_data(chip, &buf[TPM_HEADER_SIZE], - expected - TPM_HEADER_SIZE); - if (size < expected) { - dev_err(&chip->dev, "Unable to read remainder of result\n"); - size = -ETIME; - goto out; - } + size += recv_data(chip, &buf[TPM_HEADER_SIZE], + expected - TPM_HEADER_SIZE); + if (size < expected) { + dev_err(&chip->dev, "Unable to read remainder of result\n"); + size = -ETIME; + goto out; + } - if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c, - &priv->int_queue, false) < 0) { - size = -ETIME; - goto out; + if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c, + &priv->int_queue, false) < 0) { + size = -ETIME; + goto out; + } + + status = tpm_tis_status(chip); + if (status & TPM_STS_DATA_AVAIL) { /* retry? */ + dev_err(&chip->dev, "Error left over data\n"); + size = -EIO; + goto out; + } + + check_data = tpm_tis_check_data(chip, buf, size); + if (!check_data) + tpm_tis_write8(priv, TPM_STS(priv->locality), + TPM_STS_RESPONSE_RETRY); + else + break; } - status = tpm_tis_status(chip); - if (status & TPM_STS_DATA_AVAIL) { /* retry? */ - dev_err(&chip->dev, "Error left over data\n"); + if (!check_data) size = -EIO; - goto out; - } - out: tpm_tis_ready(chip); return size; @@ -453,14 +474,19 @@ static void disable_interrupts(struct tpm_chip *chip) static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len) { struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); - int rc; + int rc, i; u32 ordinal; unsigned long dur; + bool data_valid = false; - rc = tpm_tis_send_data(chip, buf, len); - if (rc < 0) - return rc; - + for (i = 0; i < TPM_RETRY && !data_valid; i++) { + rc = tpm_tis_send_data(chip, buf, len); + if (rc < 0) + return rc; + data_valid = tpm_tis_check_data(chip, buf, len); + } + if (!data_valid) + return -EIO; /* go and do it */ rc = tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_GO); if (rc < 0) diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h index d06c65b..486c2e9 100644 --- a/drivers/char/tpm/tpm_tis_core.h +++ b/drivers/char/tpm/tpm_tis_core.h @@ -34,6 +34,7 @@ enum tis_status { TPM_STS_GO = 0x20, TPM_STS_DATA_AVAIL = 0x10, TPM_STS_DATA_EXPECT = 0x08, + TPM_STS_RESPONSE_RETRY = 0x02, }; enum tis_int_flags { @@ -106,6 +107,8 @@ struct tpm_tis_phy_ops { int (*read16)(struct tpm_tis_data *data, u32 addr, u16 *result); int (*read32)(struct tpm_tis_data *data, u32 addr, u32 *result); int (*write32)(struct tpm_tis_data *data, u32 addr, u32 src); + bool (*check_data)(struct tpm_tis_data *data, const u8 *buf, + size_t len); }; static inline int tpm_tis_read_bytes(struct tpm_tis_data *data, u32 addr, -- 2.7.4