From patchwork Tue Jun 13 18:02:56 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Steffen X-Patchwork-Id: 13279133 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 23074EB64D7 for ; Tue, 13 Jun 2023 18:03:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240145AbjFMSDW (ORCPT ); Tue, 13 Jun 2023 14:03:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47754 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232105AbjFMSDV (ORCPT ); Tue, 13 Jun 2023 14:03:21 -0400 Received: from smtp2.infineon.com (smtp2.infineon.com [IPv6:2a00:18f0:1e00:4::4]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2832319B2; Tue, 13 Jun 2023 11:03:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=infineon.com; i=@infineon.com; q=dns/txt; s=IFXMAIL; t=1686679399; x=1718215399; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=S+EviMEa0wKQ948HPrnrT9RrRoeXZs1hePPbHJoq8fk=; b=ogEGAI7wXvOGi9N6sxb+y7Ra7LUx7cORUqk92YBBvC/crv/l2OA43YjW W+KzzDeYBS0rh0B3VuIB/ieMMXE3cBj4Smgk1Gs/rGX/76q7XosGi8DgT MrmwKG3SMw0XFW6/ZOc/QFaJ9J5tqt13mh7pf7GxLi3l+K1ApqdbksnFj E=; X-IronPort-AV: E=McAfee;i="6600,9927,10740"; a="41820522" X-IronPort-AV: E=Sophos;i="6.00,240,1681164000"; d="scan'208";a="41820522" Received: from unknown (HELO MUCSE819.infineon.com) ([172.23.29.45]) by smtp2.infineon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jun 2023 20:03:16 +0200 Received: from KLUSE818.infineon.com (172.28.156.171) by MUCSE819.infineon.com (172.23.29.45) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.42; Tue, 13 Jun 2023 20:03:16 +0200 Received: from ISCNPC0VBFBX.infineon.com (10.161.6.196) by KLUSE818.infineon.com (172.28.156.171) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.42; Tue, 13 Jun 2023 20:03:15 +0200 From: Alexander Steffen To: , , CC: Alexander Steffen , Subject: [PATCH v3 1/4] tpm_tis: Explicitly check for error code Date: Tue, 13 Jun 2023 20:02:56 +0200 Message-ID: <20230613180259.3525-2-Alexander.Steffen@infineon.com> X-Mailer: git-send-email 2.28.0.windows.1 In-Reply-To: <20230613180259.3525-1-Alexander.Steffen@infineon.com> References: <20230613180259.3525-1-Alexander.Steffen@infineon.com> MIME-Version: 1.0 X-Originating-IP: [10.161.6.196] X-ClientProxiedBy: MUCSE821.infineon.com (172.23.29.47) To KLUSE818.infineon.com (172.28.156.171) Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org recv_data either returns the number of received bytes, or a negative value representing an error code. Adding the return value directly to the total number of received bytes therefore looks a little weird, since it might add a negative error code to a sum of bytes. The following check for size < expected usually makes the function return ETIME in that case, so it does not cause too many problems in practice. But to make the code look cleaner and because the caller might still be interested in the original error code, explicitly check for the presence of an error code and pass that through. Cc: stable@vger.kernel.org Fixes: cb5354253af2 ("[PATCH] tpm: spacing cleanups 2") Signed-off-by: Alexander Steffen Reviewed-by: Jarkko Sakkinen --- drivers/char/tpm/tpm_tis_core.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index 558144fa707a..aaaa136044ae 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -363,8 +363,13 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count) goto out; } - size += recv_data(chip, &buf[TPM_HEADER_SIZE], - expected - TPM_HEADER_SIZE); + rc = recv_data(chip, &buf[TPM_HEADER_SIZE], + expected - TPM_HEADER_SIZE); + if (rc < 0) { + size = rc; + goto out; + } + size += rc; if (size < expected) { dev_err(&chip->dev, "Unable to read remainder of result\n"); size = -ETIME; From patchwork Tue Jun 13 18:02:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Steffen X-Patchwork-Id: 13279131 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 90A9AEB64D0 for ; Tue, 13 Jun 2023 18:03:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240096AbjFMSDU (ORCPT ); Tue, 13 Jun 2023 14:03:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47726 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240084AbjFMSDU (ORCPT ); Tue, 13 Jun 2023 14:03:20 -0400 Received: from smtp11.infineon.com (smtp11.infineon.com [IPv6:2a00:18f0:1e00:4::5]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3861E13E; Tue, 13 Jun 2023 11:03:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=infineon.com; i=@infineon.com; q=dns/txt; s=IFXMAIL; t=1686679399; x=1718215399; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=5pcn4JBKT2FT6yd1+VzPQHvpUKyuNh4EHo//3ud20mE=; b=JQ0jWuAdI90t7G7oOkkrKO4bSiUT81cJ7cfEYlKDst6nfaLQsAlgclCI nwzpEkNLVaK9AVhAx4s5xLZdYg9BpRuFS1LYZrQ50v+RgcivbV9iO5OXQ PaP6GGSK2u+MYRHbP/L76sTzt70UZWLPbS9Iplvg4cJqN3F0ixYLAe8UW 4=; X-IronPort-AV: E=McAfee;i="6600,9927,10740"; a="18551330" X-IronPort-AV: E=Sophos;i="6.00,240,1681164000"; d="scan'208";a="18551330" Received: from unknown (HELO MUCSE814.infineon.com) ([172.23.29.40]) by smtp11.infineon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jun 2023 20:03:17 +0200 Received: from KLUSE818.infineon.com (172.28.156.171) by MUCSE814.infineon.com (172.23.29.40) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.42; Tue, 13 Jun 2023 20:03:16 +0200 Received: from ISCNPC0VBFBX.infineon.com (10.161.6.196) by KLUSE818.infineon.com (172.28.156.171) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.42; Tue, 13 Jun 2023 20:03:16 +0200 From: Alexander Steffen To: , , CC: Alexander Steffen Subject: [PATCH v3 2/4] tpm_tis: Move CRC check to generic send routine Date: Tue, 13 Jun 2023 20:02:57 +0200 Message-ID: <20230613180259.3525-3-Alexander.Steffen@infineon.com> X-Mailer: git-send-email 2.28.0.windows.1 In-Reply-To: <20230613180259.3525-1-Alexander.Steffen@infineon.com> References: <20230613180259.3525-1-Alexander.Steffen@infineon.com> MIME-Version: 1.0 X-Originating-IP: [10.161.6.196] X-ClientProxiedBy: MUCSE821.infineon.com (172.23.29.47) To KLUSE818.infineon.com (172.28.156.171) Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org The CRC functionality is initialized before tpm_tis_core, so it can be used on all code paths within the module. Therefore, move the CRC check to the generic send routine, that also contains all other checks for successful command transmission, so that all those checks are in one place. Also, this ensures that tpm_tis_ready is called when a CRC failure is detected, to clear the invalid data from the TPM, which did not happen previously. Signed-off-by: Alexander Steffen Reviewed-by: Jarkko Sakkinen --- drivers/char/tpm/tpm_tis_core.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index aaaa136044ae..5ddaf24518be 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -466,6 +466,12 @@ static int tpm_tis_send_data(struct tpm_chip *chip, const u8 *buf, size_t len) goto out_err; } + rc = tpm_tis_verify_crc(priv, len, buf); + if (rc < 0) { + dev_err(&chip->dev, "CRC mismatch for command.\n"); + goto out_err; + } + return 0; out_err: @@ -510,12 +516,6 @@ static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len) if (rc < 0) return rc; - rc = tpm_tis_verify_crc(priv, len, buf); - if (rc < 0) { - dev_err(&chip->dev, "CRC mismatch for command.\n"); - return rc; - } - /* go and do it */ rc = tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_GO); if (rc < 0) From patchwork Tue Jun 13 18:02:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Steffen X-Patchwork-Id: 13279134 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8534EEB64D0 for ; Tue, 13 Jun 2023 18:03:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235960AbjFMSDZ (ORCPT ); Tue, 13 Jun 2023 14:03:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47764 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240112AbjFMSDW (ORCPT ); Tue, 13 Jun 2023 14:03:22 -0400 Received: from smtp14.infineon.com (smtp14.infineon.com [IPv6:2a00:18f0:1e00:4::6]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 86DD919B3; Tue, 13 Jun 2023 11:03:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=infineon.com; i=@infineon.com; q=dns/txt; s=IFXMAIL; t=1686679401; x=1718215401; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=xEMIE6JZW1YN5TsGLns9bWf/BYLfKZwBzKAFxtl7BSA=; b=QC6EqAsJR7gIIMY5u+gEgJoQeKy3iHMmDCKZwIMYqJ1ooUTxC8Z62Qzr pLqpM11frWfI9E+LVvoWFMYoq0Elcj75LpmnCivM6XAVa0a2H/NGKgR0W xRGJ3ZMFK8Wv9B6s1x/oRWrPeLkkvwjqnP5fnF10+gW/J+ZdNdFU/IKnJ o=; X-IronPort-AV: E=McAfee;i="6600,9927,10740"; a="16924802" X-IronPort-AV: E=Sophos;i="6.00,240,1681164000"; d="scan'208";a="16924802" Received: from unknown (HELO MUCSE812.infineon.com) ([172.23.29.38]) by smtp14.infineon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jun 2023 20:03:18 +0200 Received: from KLUSE818.infineon.com (172.28.156.171) by MUCSE812.infineon.com (172.23.29.38) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.42; Tue, 13 Jun 2023 20:03:16 +0200 Received: from ISCNPC0VBFBX.infineon.com (10.161.6.196) by KLUSE818.infineon.com (172.28.156.171) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.42; Tue, 13 Jun 2023 20:03:16 +0200 From: Alexander Steffen To: , , CC: Alexander Steffen Subject: [PATCH v3 3/4] tpm_tis: Use responseRetry to recover from data transfer errors Date: Tue, 13 Jun 2023 20:02:58 +0200 Message-ID: <20230613180259.3525-4-Alexander.Steffen@infineon.com> X-Mailer: git-send-email 2.28.0.windows.1 In-Reply-To: <20230613180259.3525-1-Alexander.Steffen@infineon.com> References: <20230613180259.3525-1-Alexander.Steffen@infineon.com> MIME-Version: 1.0 X-Originating-IP: [10.161.6.196] X-ClientProxiedBy: MUCSE821.infineon.com (172.23.29.47) To KLUSE818.infineon.com (172.28.156.171) Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org TPM responses may become damaged during transmission, for example due to bit flips on the wire. Instead of aborting when detecting such issues, the responseRetry functionality can be used to make the TPM retransmit its response and receive it again without errors. Signed-off-by: Alexander Steffen Reviewed-by: Jarkko Sakkinen --- drivers/char/tpm/tpm_tis_core.c | 37 ++++++++++++++++++++++++++------- drivers/char/tpm/tpm_tis_core.h | 1 + 2 files changed, 30 insertions(+), 8 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index 5ddaf24518be..a6d1396413a7 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -337,7 +337,7 @@ static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count) return size; } -static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count) +static int tpm_tis_try_recv(struct tpm_chip *chip, u8 *buf, size_t count) { struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); int size = 0; @@ -345,11 +345,6 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count) u32 expected; int rc; - 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) { @@ -382,7 +377,7 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count) goto out; } status = tpm_tis_status(chip); - if (status & TPM_STS_DATA_AVAIL) { /* retry? */ + if (status & TPM_STS_DATA_AVAIL) { dev_err(&chip->dev, "Error left over data\n"); size = -EIO; goto out; @@ -396,10 +391,36 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count) } out: - tpm_tis_ready(chip); return size; } +static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count) +{ + struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); + unsigned int try; + int rc = 0; + + if (count < TPM_HEADER_SIZE) + return -EIO; + + for (try = 0; try < TPM_RETRY; try++) { + rc = tpm_tis_try_recv(chip, buf, count); + + if (rc == -EIO) + /* Data transfer errors, indicated by EIO, can be + * recovered by rereading the response. + */ + tpm_tis_write8(priv, TPM_STS(priv->locality), + TPM_STS_RESPONSE_RETRY); + else + break; + } + + tpm_tis_ready(chip); + + return rc; +} + /* * If interrupts are used (signaled by an irq set in the vendor structure) * tpm.c can skip polling for the data to be available as the interrupt is diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h index 610bfadb6acf..3a6b600d22ba 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, TPM_STS_READ_ZERO = 0x23, /* bits that must be zero on read */ }; From patchwork Tue Jun 13 18:02:59 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Steffen X-Patchwork-Id: 13279132 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E4D35EB64DA for ; Tue, 13 Jun 2023 18:03:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229766AbjFMSDW (ORCPT ); Tue, 13 Jun 2023 14:03:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47742 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240119AbjFMSDU (ORCPT ); Tue, 13 Jun 2023 14:03:20 -0400 Received: from smtp2.infineon.com (smtp2.infineon.com [IPv6:2a00:18f0:1e00:4::4]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3945810F7; Tue, 13 Jun 2023 11:03:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=infineon.com; i=@infineon.com; q=dns/txt; s=IFXMAIL; t=1686679399; x=1718215399; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=6JLgbkkYt1U63xIpmUAgRDi0lykGOmT7an3pZEBkGhI=; b=a4syogtyV87Ts+C5WVfVPecZkk6xHPOfdnNeFbm4IXkxR8M5TR00gvhy FjWby6K6R5L0kiT++aQYVuvfu4IMlHG+qT7IkWq3a/GA1MCAvEzRRjge1 NzlWxwyoq5DL0/8uJEI1wGPMCWbpO5EUMTPF+CddEQU8uRHZPzs3+CZ8W E=; X-IronPort-AV: E=McAfee;i="6600,9927,10740"; a="41820531" X-IronPort-AV: E=Sophos;i="6.00,240,1681164000"; d="scan'208";a="41820531" Received: from unknown (HELO MUCSE805.infineon.com) ([172.23.29.31]) by smtp2.infineon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jun 2023 20:03:17 +0200 Received: from KLUSE818.infineon.com (172.28.156.171) by MUCSE805.infineon.com (172.23.29.31) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.42; Tue, 13 Jun 2023 20:03:17 +0200 Received: from ISCNPC0VBFBX.infineon.com (10.161.6.196) by KLUSE818.infineon.com (172.28.156.171) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.42; Tue, 13 Jun 2023 20:03:16 +0200 From: Alexander Steffen To: , , CC: Alexander Steffen Subject: [PATCH v3 4/4] tpm_tis: Resend command to recover from data transfer errors Date: Tue, 13 Jun 2023 20:02:59 +0200 Message-ID: <20230613180259.3525-5-Alexander.Steffen@infineon.com> X-Mailer: git-send-email 2.28.0.windows.1 In-Reply-To: <20230613180259.3525-1-Alexander.Steffen@infineon.com> References: <20230613180259.3525-1-Alexander.Steffen@infineon.com> MIME-Version: 1.0 X-Originating-IP: [10.161.6.196] X-ClientProxiedBy: MUCSE821.infineon.com (172.23.29.47) To KLUSE818.infineon.com (172.28.156.171) Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org Similar to the transmission of TPM responses, also the transmission of TPM commands may become corrupted. Instead of aborting when detecting such issues, try resending the command again. Signed-off-by: Alexander Steffen Reviewed-by: Jarkko Sakkinen --- drivers/char/tpm/tpm_tis_core.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index a6d1396413a7..7b13ad4bd6dd 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -532,10 +532,17 @@ static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len) int rc; u32 ordinal; unsigned long dur; + unsigned int try; - rc = tpm_tis_send_data(chip, buf, len); - if (rc < 0) - return rc; + for (try = 0; try < TPM_RETRY; try++) { + rc = tpm_tis_send_data(chip, buf, len); + if (rc >= 0) + /* Data transfer done successfully */ + break; + else if (rc != -EIO) + /* Data transfer failed, not recoverable */ + return rc; + } /* go and do it */ rc = tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_GO);