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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1DE1AECAAA1 for ; Sun, 23 Oct 2022 04:41:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229690AbiJWEk7 (ORCPT ); Sun, 23 Oct 2022 00:40:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56324 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229515AbiJWEk6 (ORCPT ); Sun, 23 Oct 2022 00:40:58 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CB70C6B145; Sat, 22 Oct 2022 21:40:54 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 1976BB80CD9; Sun, 23 Oct 2022 04:40:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 65EF8C433C1; Sun, 23 Oct 2022 04:40:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666500051; bh=gPyxyOwPQPkB61qgMrc1kRWRUwmWalIc2y4yWNTdtZ4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=EU6FehWu7G04TYAKUpYalYneBKLVsDDS/UaEBvYVQziQGZcyyVb4sYdJ+i5GwvOrg b+XeO6+OjrW7vogJuaLrVEXyWcY+U1NKC+qaFEF6bU4mMvw78RcHNA6TzVOjjiX+N2 oSjZGebk8e4s5/w7oNeOUuujkZXwsJ8YcpXpG27eeAnpiUE6zbyVGes8ZXsYyOPYRe pDPdGi8W1+/WPrD+FATOn1k22VtWiiK0+CfhCARqk9L6kB1rL6a6kN/FhDhnuEDppy 5puCbTTyNLnmFGVPMExoRCawZfINh83REcfVB1I1ncWFwJVgbeX1W3hY8sU7XKaf4T /dsBD48uemmsA== Date: Sun, 23 Oct 2022 07:40:44 +0300 From: Jarkko Sakkinen To: Lino Sanfilippo Cc: peterhuewe@gmx.de, jgg@ziepe.ca, stefanb@linux.vnet.ibm.com, linux@mniewoehner.de, linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, jandryuk@gmail.com, pmenzel@molgen.mpg.de, l.sanfilippo@kunbus.com, lukas@wunner.de, p.rosenberger@kunbus.com Subject: Re: [PATCH v8 08/11] tpm, tpm: Implement usage counter for locality Message-ID: References: <20221017235732.10145-1-LinoSanfilippo@gmx.de> <20221017235732.10145-9-LinoSanfilippo@gmx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20221017235732.10145-9-LinoSanfilippo@gmx.de> Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On Tue, Oct 18, 2022 at 01:57:29AM +0200, Lino Sanfilippo wrote: > From: Lino Sanfilippo > > Implement a usage counter for the (default) locality used by the TPM TIS > driver: > Request the locality from the TPM if it has not been claimed yet, otherwise > only increment the counter. Also release the locality if the counter is 0 > otherwise only decrement the counter. Ensure thread-safety by protecting > the counter with a mutex. > > This allows to request and release the locality from a thread and the > interrupt handler at the same time without the danger to interfere with > each other. > > By doing this refactor the names of the amended functions to use the proper > prefix. > > Signed-off-by: Lino Sanfilippo > Tested-by: Michael Niewöhner > --- > drivers/char/tpm/tpm_tis_core.c | 75 ++++++++++++++++++++++----------- > drivers/char/tpm/tpm_tis_core.h | 2 + > 2 files changed, 53 insertions(+), 24 deletions(-) > > diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c > index 4336f7ea8c2b..79dfab65976f 100644 > --- a/drivers/char/tpm/tpm_tis_core.c > +++ b/drivers/char/tpm/tpm_tis_core.c > @@ -165,16 +165,27 @@ static bool check_locality(struct tpm_chip *chip, int l) > return false; > } > > -static int release_locality(struct tpm_chip *chip, int l) > +static int tpm_tis_release_locality_locked(struct tpm_tis_data *priv, int l) Nit: usually you would actually use "unlocked" here, not locked. Probably best name would be __tpm_tis_release_locality(). > +{ > + tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY); > + > + return 0; > +} > + > +static int tpm_tis_release_locality(struct tpm_chip *chip, int l) > { > struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); > > - tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY); > + mutex_lock(&priv->locality_count_mutex); > + priv->locality_count--; > + if (priv->locality_count == 0) > + tpm_tis_release_locality_locked(priv, l); > + mutex_unlock(&priv->locality_count_mutex); > > return 0; > } Since the function pointer has the word "relinquish" and not "release", perhaps these should also use that word for consistency. > > -static int request_locality(struct tpm_chip *chip, int l) > +static int tpm_tis_request_locality_locked(struct tpm_chip *chip, int l) > { > struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); > unsigned long stop, timeout; > @@ -215,6 +226,20 @@ static int request_locality(struct tpm_chip *chip, int l) > return -1; > } > > +static int tpm_tis_request_locality(struct tpm_chip *chip, int l) > +{ > + struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); > + int ret = 0; > + > + mutex_lock(&priv->locality_count_mutex); > + if (priv->locality_count == 0) > + ret = tpm_tis_request_locality_locked(chip, l); > + if (!ret) > + priv->locality_count++; > + mutex_unlock(&priv->locality_count_mutex); > + return ret; > +} > + > static u8 tpm_tis_status(struct tpm_chip *chip) > { > struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); > @@ -682,7 +707,7 @@ static int probe_itpm(struct tpm_chip *chip) > if (vendor != TPM_VID_INTEL) > return 0; > > - if (request_locality(chip, 0) != 0) > + if (tpm_tis_request_locality(chip, 0) != 0) > return -EBUSY; > > rc = tpm_tis_send_data(chip, cmd_getticks, len); > @@ -703,7 +728,7 @@ static int probe_itpm(struct tpm_chip *chip) > > out: > tpm_tis_ready(chip); > - release_locality(chip, priv->locality); > + tpm_tis_release_locality(chip, priv->locality); > > return rc; > } > @@ -762,7 +787,7 @@ static int tpm_tis_gen_interrupt(struct tpm_chip *chip) > cap_t cap; > int ret; > > - ret = request_locality(chip, 0); > + ret = tpm_tis_request_locality(chip, 0); > if (ret < 0) > return ret; > > @@ -771,7 +796,7 @@ static int tpm_tis_gen_interrupt(struct tpm_chip *chip) > else > ret = tpm1_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, desc, 0); > > - release_locality(chip, 0); > + tpm_tis_release_locality(chip, 0); > > return ret; > } > @@ -796,33 +821,33 @@ static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask, > } > priv->irq = irq; > > - rc = request_locality(chip, 0); > + rc = tpm_tis_request_locality(chip, 0); > if (rc < 0) > return rc; > > rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality), > &original_int_vec); > if (rc < 0) { > - release_locality(chip, priv->locality); > + tpm_tis_release_locality(chip, priv->locality); > return rc; > } > > rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), irq); > if (rc < 0) { > - release_locality(chip, priv->locality); > + tpm_tis_release_locality(chip, priv->locality); > return rc; > } > > rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &int_status); > if (rc < 0) { > - release_locality(chip, priv->locality); > + tpm_tis_release_locality(chip, priv->locality); > return rc; > } > > /* Clear all existing */ > rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), int_status); > if (rc < 0) { > - release_locality(chip, priv->locality); > + tpm_tis_release_locality(chip, priv->locality); > return rc; > } > > @@ -830,11 +855,11 @@ static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask, > rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), > intmask | TPM_GLOBAL_INT_ENABLE); > if (rc < 0) { > - release_locality(chip, priv->locality); > + tpm_tis_release_locality(chip, priv->locality); > return rc; > } > > - release_locality(chip, priv->locality); > + tpm_tis_release_locality(chip, priv->locality); > clear_bit(TPM_TIS_IRQ_TESTED, &priv->flags); > > /* Generate an interrupt by having the core call through to > @@ -970,8 +995,8 @@ static const struct tpm_class_ops tpm_tis = { > .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID, > .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID, > .req_canceled = tpm_tis_req_canceled, > - .request_locality = request_locality, > - .relinquish_locality = release_locality, > + .request_locality = tpm_tis_request_locality, > + .relinquish_locality = tpm_tis_release_locality, > .clk_enable = tpm_tis_clkrun_enable, > }; > > @@ -1005,6 +1030,8 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq, > priv->timeout_min = TPM_TIMEOUT_USECS_MIN; > priv->timeout_max = TPM_TIMEOUT_USECS_MAX; > priv->phy_ops = phy_ops; > + priv->locality_count = 0; > + mutex_init(&priv->locality_count_mutex); > > dev_set_drvdata(&chip->dev, priv); > > @@ -1083,14 +1110,14 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq, > > intmask &= ~TPM_GLOBAL_INT_ENABLE; > > - rc = request_locality(chip, 0); > + rc = tpm_tis_request_locality(chip, 0); > if (rc < 0) { > rc = -ENODEV; > goto out_err; > } > > tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask); > - release_locality(chip, 0); > + tpm_tis_release_locality(chip, 0); > > rc = tpm_chip_start(chip); > if (rc) > @@ -1124,13 +1151,13 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq, > * proper timeouts for the driver. > */ > > - rc = request_locality(chip, 0); > + rc = tpm_tis_request_locality(chip, 0); > if (rc < 0) > goto out_err; > > rc = tpm_get_timeouts(chip); > > - release_locality(chip, 0); > + tpm_tis_release_locality(chip, 0); > > if (rc) { > dev_err(dev, "Could not get TPM timeouts and durations\n"); > @@ -1150,11 +1177,11 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq, > dev_err(&chip->dev, FW_BUG > "TPM interrupt not working, polling instead\n"); > > - rc = request_locality(chip, 0); > + rc = tpm_tis_request_locality(chip, 0); > if (rc < 0) > goto out_err; > disable_interrupts(chip); > - release_locality(chip, 0); > + tpm_tis_release_locality(chip, 0); > } > } > > @@ -1221,13 +1248,13 @@ int tpm_tis_resume(struct device *dev) > * an error code but for unknown reason it isn't handled. > */ > if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) { > - ret = request_locality(chip, 0); > + ret = tpm_tis_request_locality(chip, 0); > if (ret < 0) > return ret; > > tpm1_do_selftest(chip); > > - release_locality(chip, 0); > + tpm_tis_release_locality(chip, 0); > } > > return 0; > diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h > index 2deef11c88db..13bdcf38e56f 100644 > --- a/drivers/char/tpm/tpm_tis_core.h > +++ b/drivers/char/tpm/tpm_tis_core.h > @@ -91,6 +91,8 @@ enum tpm_tis_flags { > > struct tpm_tis_data { > u16 manufacturer_id; > + struct mutex locality_count_mutex; BTW, why mutex and not spinlock? Hmm.. also I think you might have given feedback already on this but could the lock cover the whole struct instead of a counter? I tried to dig lore for earlier response but could not find. I'm sorry if I'm asking the same question again. You could probably use rcu for that. > + unsigned int locality_count; > int locality; > int irq; > unsigned int int_mask; > -- > 2.36.1 > BR, Jarkko