From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DF9DA1FC11F; Thu, 6 Mar 2025 22:23:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741299797; cv=none; b=rPqwoOtMYZcegWVSxJBin3PwrIhJGvj05kZf6rx4TNCBfhTMJ0BQ8Ons0W/zE/CNzPOuP793Tsdj8qULAUuFX0oMYhWyzLOiK+o9z3sqbCRhZv89igMHwwpFgAVjLXZzh/P8PXSK2b5DShz7gHmg9BOL4LLj93i1bzsP+zGStIE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741299797; c=relaxed/simple; bh=dS7uAY66ezka3trq24QAakPf45oJ8bb0CfmMNsXEmGE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=FjKtgHXKpoSrT8cjBZSwkRz0yPMrh1OuywNtIUAE59orTflBu+Zde+rsWpdx0/rDdp+Es/N/621U+DEHh225OYgDJRUSarPNmV9qziwj40X4KPpox99Snh85d35JE0XHbzWsvKDQ5qEqTcbpVTUWB29wb1PRRYohhx9VGAt5zYA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=I9Zgqrs8; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="I9Zgqrs8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C2515C4CEE0; Thu, 6 Mar 2025 22:23:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741299796; bh=dS7uAY66ezka3trq24QAakPf45oJ8bb0CfmMNsXEmGE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=I9Zgqrs8Pm4/+RzZdH4PKqQZbCqlIeuwMgFKC0XQW+cEE5prWgM1yGUSAS8qIsrwq I3Ij1NsQxGeNziKizBpk2akoXe4aiJWZAq98X8GWdp1MBbwhbDuedYjLFf6E0Uzk3Z ciH7uKtwLhR5Sn43CAQI6QzGe4NVS2jDJNfcATxUUsEVBP/frn5BG2JcVOBForifrv JW411vqeZ+BvAc/jshGEQMyBlCMIhZGVh08N/7DLzqRRsr5WUrK6vFsaSAParun83Z 0zCxnO7TOA5tkEpbPFQWMGCjHqJtwoCZbRvQWBxjV9f+jgM3Xuupv9o72nwiIhuUuk eia3Mh7Uu/r0g== Date: Fri, 7 Mar 2025 00:23:11 +0200 From: Jarkko Sakkinen To: Jonathan McDowell Cc: Peter Huewe , Jason Gunthorpe , James Bottomley , Stefan Berger , linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] tpm, tpm_tis: Workaround failed command reception on Infineon devices Message-ID: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Thu, Mar 06, 2025 at 09:00:56AM +0000, Jonathan McDowell wrote: > From: Jonathan McDowell > > Some Infineon devices have a issue where the status register will get > stuck with a quick REQUEST_USE / COMMAND_READY sequence. This is not > simply a matter of requiring a longer timeout; the work around is to > retry the command submission. Add appropriate logic to do this in the > send path. > > This is fixed in later firmware revisions, but those are not always > available, and cannot generally be easily updated from outside a > firmware environment. > > Testing has been performed with a simple repeated loop of doing a > TPM2_CC_GET_CAPABILITY for TPM_CAP_PROP_MANUFACTURER using the Go code > at: > > https://the.earth.li/~noodles/tpm-stuff/timeout-reproducer-simple.go > > It can take several hours to reproduce, and millions of operations. > > Signed-off-by: Jonathan McDowell > --- > drivers/char/tpm/tpm_tis_core.c | 17 ++++++++++++++--- > drivers/char/tpm/tpm_tis_core.h | 1 + > include/linux/tpm.h | 1 + > 3 files changed, 16 insertions(+), 3 deletions(-) > > diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c > index 167d71747666..e4eae206a353 100644 > --- a/drivers/char/tpm/tpm_tis_core.c > +++ b/drivers/char/tpm/tpm_tis_core.c > @@ -464,7 +464,10 @@ static int tpm_tis_send_data(struct tpm_chip *chip, const u8 *buf, size_t len) > > if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c, > &priv->int_queue, false) < 0) { > - rc = -ETIME; > + if (test_bit(TPM_TIS_STATUS_WORKAROUND, &priv->flags)) > + rc = -EAGAIN; > + else > + rc = -ETIME; > goto out_err; > } > status = tpm_tis_status(chip); > @@ -481,7 +484,10 @@ static int tpm_tis_send_data(struct tpm_chip *chip, const u8 *buf, size_t len) > > if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c, > &priv->int_queue, false) < 0) { > - rc = -ETIME; > + if (test_bit(TPM_TIS_STATUS_WORKAROUND, &priv->flags)) > + rc = -EAGAIN; > + else > + rc = -ETIME; I'd encapsulate this inside wait_for_tpm_stat(). > goto out_err; > } > status = tpm_tis_status(chip); > @@ -546,9 +552,11 @@ static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len) > if (rc >= 0) > /* Data transfer done successfully */ > break; > - else if (rc != -EIO) > + else if (rc != EAGAIN && rc != -EIO) > /* Data transfer failed, not recoverable */ > return rc; > + > + usleep_range(priv->timeout_min, priv->timeout_max); > } > > /* go and do it */ > @@ -1144,6 +1152,9 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq, > priv->timeout_max = TIS_TIMEOUT_MAX_ATML; > } > > + if (priv->manufacturer_id == TPM_VID_IFX) > + set_bit(TPM_TIS_STATUS_WORKAROUND, &priv->flags); > + > if (is_bsw()) { > priv->ilb_base_addr = ioremap(INTEL_LEGACY_BLK_BASE_ADDR, > ILB_REMAP_SIZE); > diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h > index 690ad8e9b731..ce97b58dc005 100644 > --- a/drivers/char/tpm/tpm_tis_core.h > +++ b/drivers/char/tpm/tpm_tis_core.h > @@ -89,6 +89,7 @@ enum tpm_tis_flags { > TPM_TIS_INVALID_STATUS = 1, > TPM_TIS_DEFAULT_CANCELLATION = 2, > TPM_TIS_IRQ_TESTED = 3, > + TPM_TIS_STATUS_WORKAROUND = 4, TPM_TIS_TIMEOUT_AGAIN or maybe *_REPEAT? The current name does not tell anything. > }; > > struct tpm_tis_data { > diff --git a/include/linux/tpm.h b/include/linux/tpm.h > index 20a40ade8030..6c3125300c00 100644 > --- a/include/linux/tpm.h > +++ b/include/linux/tpm.h > @@ -335,6 +335,7 @@ enum tpm2_cc_attrs { > #define TPM_VID_WINBOND 0x1050 > #define TPM_VID_STM 0x104A > #define TPM_VID_ATML 0x1114 > +#define TPM_VID_IFX 0x15D1 > > enum tpm_chip_flags { > TPM_CHIP_FLAG_BOOTSTRAPPED = BIT(0), > -- > 2.48.1 > BR, Jarkko