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=-17.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 6832EC64E7B for ; Wed, 2 Dec 2020 16:50:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 107CC2222E for ; Wed, 2 Dec 2020 16:50:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730546AbgLBQuS (ORCPT ); Wed, 2 Dec 2020 11:50:18 -0500 Received: from mail.kernel.org ([198.145.29.99]:55784 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727227AbgLBQuS (ORCPT ); Wed, 2 Dec 2020 11:50:18 -0500 Date: Wed, 2 Dec 2020 18:49:31 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606927776; bh=lG8psMOaRNzxmyJyuNq9VDxKWQ1gRYRmHSVUGDGFM5I=; h=From:To:Cc:Subject:References:In-Reply-To:From; b=OtZ4rewqFpV85xXmS+H9cW9KGGaoJ9NhhKguYiMxy1nES3XGeJQ+zu2gdLhctVyPH VLIXEmfgtll0LcHwQxwiNxOJM32PMlf0kGndTAua40O+7adSnuG3o9XWAo4oivwtSI Shg3Jw4xoi4JEvdvlIAc4jgWTHirJTRWrDq8kNFc= From: Jarkko Sakkinen To: Jerry Snitselaar , Jani Nikula Cc: linux-kernel@vger.kernel.org, linux-integrity@vger.kernel.org, Jason Gunthorpe , Peter Huewe , James Bottomley , Matthew Garrett , Hans de Goede Subject: Re: [PATCH v2] tpm_tis: Disable interrupts if interrupt storm detected Message-ID: <20201202164931.GA91318@kernel.org> References: <20201130232338.106892-1-jsnitsel@redhat.com> <20201201025807.162241-1-jsnitsel@redhat.com> <87czzujjg1.fsf@redhat.com> <878sahmh5w.fsf@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <878sahmh5w.fsf@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 01, 2020 at 12:59:23PM -0700, Jerry Snitselaar wrote: > > Jerry Snitselaar @ 2020-11-30 20:26 MST: > > > Jerry Snitselaar @ 2020-11-30 19:58 MST: > > > >> When enabling the interrupt code for the tpm_tis driver we have > >> noticed some systems have a bios issue causing an interrupt storm to > >> occur. The issue isn't limited to a single tpm or system manufacturer > >> so keeping a denylist of systems with the issue isn't optimal. Instead > >> try to detect the problem occurring, disable interrupts, and revert to > >> polling when it happens. > >> > >> Cc: Jarkko Sakkinen > >> Cc: Jason Gunthorpe > >> Cc: Peter Huewe > >> Cc: James Bottomley > >> Cc: Matthew Garrett > >> Cc: Hans de Goede > >> Signed-off-by: Jerry Snitselaar > >> --- > >> v2: drop tpm_tis specific workqueue and use just system_wq > >> > >> drivers/char/tpm/tpm_tis_core.c | 27 +++++++++++++++++++++++++++ > >> drivers/char/tpm/tpm_tis_core.h | 2 ++ > >> 2 files changed, 29 insertions(+) > >> > >> diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c > >> index 23b60583928b..72cc8a5a152c 100644 > >> --- a/drivers/char/tpm/tpm_tis_core.c > >> +++ b/drivers/char/tpm/tpm_tis_core.c > >> @@ -24,6 +24,8 @@ > >> #include > >> #include > >> #include > >> +#include > >> +#include > >> #include "tpm.h" > >> #include "tpm_tis_core.h" > >> > >> @@ -745,9 +747,23 @@ static irqreturn_t tis_int_handler(int dummy, void *dev_id) > >> { > >> struct tpm_chip *chip = dev_id; > >> struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); > >> + static bool check_storm = true; > >> + static unsigned int check_start; > >> u32 interrupt; > >> int i, rc; > >> > >> + if (unlikely(check_storm)) { > >> + if (!check_start) { > >> + check_start = jiffies_to_msecs(jiffies); > >> + } else if ((kstat_irqs(priv->irq) > 1000) && > >> + (jiffies_to_msecs(jiffies) - check_start < 500)) { > >> + check_storm = false; > >> + schedule_work(&priv->storm_work); > >> + } else if (jiffies_to_msecs(jiffies) - check_start >= 500) { > >> + check_storm = false; > >> + } > >> + } > >> + > >> rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt); > >> if (rc < 0) > >> return IRQ_NONE; > >> @@ -987,6 +1003,14 @@ static const struct tpm_class_ops tpm_tis = { > >> .clk_enable = tpm_tis_clkrun_enable, > >> }; > >> > >> +static void tpm_tis_storm_work(struct work_struct *work) > >> +{ > >> + struct tpm_tis_data *priv = container_of(work, struct tpm_tis_data, storm_work); > >> + > >> + disable_interrupts(priv->chip); > >> + dev_warn(&priv->chip->dev, "Interrupt storm detected, using polling.\n"); > >> +} > >> + > >> int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq, > >> const struct tpm_tis_phy_ops *phy_ops, > >> acpi_handle acpi_dev_handle) > >> @@ -1003,6 +1027,9 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq, > >> if (IS_ERR(chip)) > >> return PTR_ERR(chip); > >> > >> + priv->chip = chip; > >> + INIT_WORK(&priv->storm_work, tpm_tis_storm_work); > >> + > >> #ifdef CONFIG_ACPI > >> chip->acpi_dev_handle = acpi_dev_handle; > >> #endif > >> diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h > >> index edeb5dc61c95..5630f294dc0c 100644 > >> --- a/drivers/char/tpm/tpm_tis_core.h > >> +++ b/drivers/char/tpm/tpm_tis_core.h > >> @@ -95,6 +95,8 @@ struct tpm_tis_data { > >> u16 clkrun_enabled; > >> wait_queue_head_t int_queue; > >> wait_queue_head_t read_queue; > >> + struct work_struct storm_work; > >> + struct tpm_chip *chip; > >> const struct tpm_tis_phy_ops *phy_ops; > >> unsigned short rng_quality; > >> }; > > > > I've tested this with the Intel platform that has an Infineon chip that > > I found the other week. It works, but isn't the complete fix. With this > > on top of James' patchset I sometimes see the message "Lost Interrupt > > waiting for TPM stat", so I guess there needs to be a check in > > wait_for_tpm_stat and request_locality to see if interrupts were > > disabled when the wait_event_interruptible_timeout call times out. > > As kernel test robot pointed out. kstat_irqs isn't visible when tpm_tis > builds as a module. It looks like it is only called by kstat_irq_usrs, > and that is only by the fs/proc code. I have a patch to export it, but > the i915 driver open codes their own version instead of using it. Is > there any reason not to export it? If you add a patch that exports it, then for coherency it'd be better to also patch i915 driver. Jani? /Jarkko