From: Peter Huewe <peterhuewe@gmx.de> To: Nayna Jain <nayna@linux.vnet.ibm.com>, tpmdd-devel@lists.sourceforge.net Cc: tpmdd@selhorst.net, jarkko.sakkinen@linux.intel.com, jgunthorpe@obsidianresearch.com, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ima-devel@lists.sourceforge.net, patrickc@us.ibm.com Subject: Re: [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount Date: Mon, 07 Aug 2017 13:52:34 +0200 [thread overview] Message-ID: <E37DFCB0-2E74-45F6-B2DF-70EF59F310BC@gmx.de> (raw) In-Reply-To: <20170807114632.1339-1-nayna@linux.vnet.ibm.com> Am 7. August 2017 13:46:32 MESZ schrieb Nayna Jain <nayna@linux.vnet.ibm.com>: >The TPM burstcount status indicates the number of bytes that can >be sent to the TPM without causing bus wait states. Effectively, >it is the number of empty bytes in the command FIFO. Further, >some TPMs have a static burstcount, when the value remains zero >until the entire FIFO is empty. > >This patch ignores burstcount, permitting wait states, and thus >writes the command as fast as the TPM can accept the bytes. >The performance of a 34 byte extend on a TPM 1.2 improved from >52 msec to 11 msec. > >Suggested-by: Ken Goldman <kgold@linux.vnet.ibm.com> in >conjunction with the TPM Device Driver work group. >Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com> >Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Are you sure this is a good idea? On lpc systems this more or less stalls the bus, including keyboard/mouse (if connected via superio lpc). On which systems have you tested this? Spi/Lpc? Architecture? This might not be noticable for small transfers, but think about much larger transfers.... Imho: NACK from my side. Thanks, Peter >--- >drivers/char/tpm/tpm_tis_core.c | 45 >++--------------------------------------- > 1 file changed, 2 insertions(+), 43 deletions(-) > >diff --git a/drivers/char/tpm/tpm_tis_core.c >b/drivers/char/tpm/tpm_tis_core.c >index b617b2eeb080..478cbc0f61c3 100644 >--- a/drivers/char/tpm/tpm_tis_core.c >+++ b/drivers/char/tpm/tpm_tis_core.c >@@ -255,9 +255,7 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 >*buf, size_t count) >static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t >len) > { > struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); >- int rc, status, burstcnt; >- size_t count = 0; >- bool itpm = priv->flags & TPM_TIS_ITPM_WORKAROUND; >+ int rc, status; > > status = tpm_tis_status(chip); > if ((status & TPM_STS_COMMAND_READY) == 0) { >@@ -270,49 +268,10 @@ static int tpm_tis_send_data(struct tpm_chip >*chip, u8 *buf, size_t len) > } > } > >- while (count < len - 1) { >- burstcnt = get_burstcount(chip); >- if (burstcnt < 0) { >- dev_err(&chip->dev, "Unable to read burstcount\n"); >- rc = burstcnt; >- goto out_err; >- } >- burstcnt = min_t(int, burstcnt, len - count - 1); >- rc = tpm_tis_write_bytes(priv, TPM_DATA_FIFO(priv->locality), >- burstcnt, buf + count); >- if (rc < 0) >- goto out_err; >- >- count += burstcnt; >- >- if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c, >- &priv->int_queue, false) < 0) { >- rc = -ETIME; >- goto out_err; >- } >- status = tpm_tis_status(chip); >- if (!itpm && (status & TPM_STS_DATA_EXPECT) == 0) { >- rc = -EIO; >- goto out_err; >- } >- } >- >- /* write last byte */ >- rc = tpm_tis_write8(priv, TPM_DATA_FIFO(priv->locality), buf[count]); >+ rc = tpm_tis_write_bytes(priv, TPM_DATA_FIFO(priv->locality), len, >buf); > if (rc < 0) > goto out_err; > >- if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c, >- &priv->int_queue, false) < 0) { >- rc = -ETIME; >- goto out_err; >- } >- status = tpm_tis_status(chip); >- if (!itpm && (status & TPM_STS_DATA_EXPECT) != 0) { >- rc = -EIO; >- goto out_err; >- } >- > return 0; > > out_err: -- Sent from my mobile
WARNING: multiple messages have this Message-ID (diff)
From: peterhuewe@gmx.de (Peter Huewe) To: linux-security-module@vger.kernel.org Subject: [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount Date: Mon, 07 Aug 2017 13:52:34 +0200 [thread overview] Message-ID: <E37DFCB0-2E74-45F6-B2DF-70EF59F310BC@gmx.de> (raw) In-Reply-To: <20170807114632.1339-1-nayna@linux.vnet.ibm.com> Am 7. August 2017 13:46:32 MESZ schrieb Nayna Jain <nayna@linux.vnet.ibm.com>: >The TPM burstcount status indicates the number of bytes that can >be sent to the TPM without causing bus wait states. Effectively, >it is the number of empty bytes in the command FIFO. Further, >some TPMs have a static burstcount, when the value remains zero >until the entire FIFO is empty. > >This patch ignores burstcount, permitting wait states, and thus >writes the command as fast as the TPM can accept the bytes. >The performance of a 34 byte extend on a TPM 1.2 improved from >52 msec to 11 msec. > >Suggested-by: Ken Goldman <kgold@linux.vnet.ibm.com> in >conjunction with the TPM Device Driver work group. >Signed-off-by: Nayna Jain <nayna@linux.vnet.ibm.com> >Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Are you sure this is a good idea? On lpc systems this more or less stalls the bus, including keyboard/mouse (if connected via superio lpc). On which systems have you tested this? Spi/Lpc? Architecture? This might not be noticable for small transfers, but think about much larger transfers.... Imho: NACK from my side. Thanks, Peter >--- >drivers/char/tpm/tpm_tis_core.c | 45 >++--------------------------------------- > 1 file changed, 2 insertions(+), 43 deletions(-) > >diff --git a/drivers/char/tpm/tpm_tis_core.c >b/drivers/char/tpm/tpm_tis_core.c >index b617b2eeb080..478cbc0f61c3 100644 >--- a/drivers/char/tpm/tpm_tis_core.c >+++ b/drivers/char/tpm/tpm_tis_core.c >@@ -255,9 +255,7 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 >*buf, size_t count) >static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t >len) > { > struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); >- int rc, status, burstcnt; >- size_t count = 0; >- bool itpm = priv->flags & TPM_TIS_ITPM_WORKAROUND; >+ int rc, status; > > status = tpm_tis_status(chip); > if ((status & TPM_STS_COMMAND_READY) == 0) { >@@ -270,49 +268,10 @@ static int tpm_tis_send_data(struct tpm_chip >*chip, u8 *buf, size_t len) > } > } > >- while (count < len - 1) { >- burstcnt = get_burstcount(chip); >- if (burstcnt < 0) { >- dev_err(&chip->dev, "Unable to read burstcount\n"); >- rc = burstcnt; >- goto out_err; >- } >- burstcnt = min_t(int, burstcnt, len - count - 1); >- rc = tpm_tis_write_bytes(priv, TPM_DATA_FIFO(priv->locality), >- burstcnt, buf + count); >- if (rc < 0) >- goto out_err; >- >- count += burstcnt; >- >- if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c, >- &priv->int_queue, false) < 0) { >- rc = -ETIME; >- goto out_err; >- } >- status = tpm_tis_status(chip); >- if (!itpm && (status & TPM_STS_DATA_EXPECT) == 0) { >- rc = -EIO; >- goto out_err; >- } >- } >- >- /* write last byte */ >- rc = tpm_tis_write8(priv, TPM_DATA_FIFO(priv->locality), buf[count]); >+ rc = tpm_tis_write_bytes(priv, TPM_DATA_FIFO(priv->locality), len, >buf); > if (rc < 0) > goto out_err; > >- if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c, >- &priv->int_queue, false) < 0) { >- rc = -ETIME; >- goto out_err; >- } >- status = tpm_tis_status(chip); >- if (!itpm && (status & TPM_STS_DATA_EXPECT) != 0) { >- rc = -EIO; >- goto out_err; >- } >- > return 0; > > out_err: -- Sent from my mobile -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2017-08-07 11:53 UTC|newest] Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-08-07 11:46 [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount Nayna Jain 2017-08-07 11:46 ` Nayna Jain 2017-08-07 11:52 ` Peter Huewe [this message] 2017-08-07 11:52 ` Peter Huewe 2017-08-07 14:25 ` Nayna 2017-08-07 14:25 ` Nayna 2017-08-08 21:50 ` Jarkko Sakkinen 2017-08-08 21:50 ` Jarkko Sakkinen 2017-08-08 19:11 ` Jarkko Sakkinen 2017-08-08 19:11 ` Jarkko Sakkinen 2017-08-09 20:23 ` [tpmdd-devel] " Ken Goldman 2017-08-09 20:23 ` Ken Goldman 2017-08-09 20:23 ` Ken Goldman 2017-08-09 20:43 ` Aw: " Peter Huewe 2017-08-09 20:43 ` Peter Huewe 2017-08-11 21:54 ` Ken Goldman 2017-08-11 21:54 ` Ken Goldman 2017-08-11 21:54 ` Ken Goldman [not found] ` <20170814101046.5hqrkaqmfvl7ugwj@linux.intel.com> 2017-08-16 19:51 ` Ken Goldman 2017-08-16 19:51 ` Ken Goldman 2017-08-16 19:51 ` Ken Goldman 2017-08-09 20:25 ` Ken Goldman 2017-08-09 20:25 ` Ken Goldman 2017-08-09 20:25 ` Ken Goldman 2017-08-09 21:00 ` Aw: " Peter Huewe 2017-08-09 21:00 ` Peter Huewe 2017-08-11 11:14 ` Jarkko Sakkinen 2017-08-11 11:14 ` Jarkko Sakkinen 2017-08-11 15:30 ` Mimi Zohar 2017-08-11 15:30 ` Mimi Zohar 2017-08-14 10:51 ` Jarkko Sakkinen 2017-08-14 10:51 ` Jarkko Sakkinen 2017-08-14 10:56 ` Jarkko Sakkinen 2017-08-14 10:56 ` Jarkko Sakkinen 2017-08-14 12:03 ` Mimi Zohar 2017-08-14 12:03 ` Mimi Zohar 2017-08-15 6:08 ` Jarkko Sakkinen 2017-08-15 6:08 ` Jarkko Sakkinen 2017-08-14 12:12 ` Mimi Zohar 2017-08-14 12:12 ` Mimi Zohar 2017-08-15 6:09 ` Jarkko Sakkinen 2017-08-15 6:09 ` Jarkko Sakkinen 2017-08-11 21:32 ` Aw: " Ken Goldman 2017-08-11 21:32 ` Ken Goldman 2017-08-11 21:32 ` Ken Goldman 2017-08-13 23:53 ` msuchanek 2017-08-13 23:53 ` msuchanek 2017-08-15 22:02 ` Ken Goldman 2017-08-15 22:02 ` Ken Goldman 2017-08-15 22:02 ` Ken Goldman 2017-08-16 10:24 ` Michal Suchánek 2017-08-16 10:24 ` Michal Suchánek 2017-08-11 21:42 ` [Linux-ima-devel] " Ken Goldman 2017-08-11 21:42 ` Ken Goldman 2017-08-11 21:42 ` Ken Goldman 2017-08-08 19:07 ` Jarkko Sakkinen 2017-08-08 19:07 ` Jarkko Sakkinen
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