linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: amirmizi6@gmail.com
To: Eyal.Cohen@nuvoton.com, jarkko.sakkinen@linux.intel.com,
	oshrialkoby85@gmail.com, alexander.steffen@infineon.com,
	robh+dt@kernel.org, mark.rutland@arm.com, peterhuewe@gmx.de,
	jgg@ziepe.ca, arnd@arndb.de, gregkh@linuxfoundation.org
Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-integrity@vger.kernel.org, oshri.alkoby@nuvoton.com,
	tmaimon77@gmail.com, gcwilson@us.ibm.com, kgoldman@us.ibm.com,
	Dan.Morav@nuvoton.com, oren.tanami@nuvoton.com,
	shmulik.hager@nuvoton.com, amir.mizinski@nuvoton.com,
	Amir Mizinski <amirmizi6@gmail.com>
Subject: [PATCH v3 4/7] char: tpm: Fix expected bit handling and send all bytes in one shot without last byte in exception
Date: Mon, 10 Feb 2020 18:28:35 +0200	[thread overview]
Message-ID: <20200210162838.173903-5-amirmizi6@gmail.com> (raw)
In-Reply-To: <20200210162838.173903-1-amirmizi6@gmail.com>

From: Amir Mizinski <amirmizi6@gmail.com>

Today, actual implementation for send massage is not correct. We check and
 loop only on TPM_STS.stsValid bit and next we single check TPM_STS.expect
 bit value.
TPM_STS.expected bit shall be checked in the same time of
 TPM_STS.stsValid, and should be repeated until timeout_A.
To aquire that, "wait_for_tpm_stat" function is modified to
 "wait_for_tpm_stat_result". this function read regulary status register
 and check bit defined by "mask" to reach value defined in "mask_result"
 (that way a bit in mask can be checked if reached 1 or 0).

Respectively, to send message as defined in
 TCG_DesignPrinciples_TPM2p0Driver_vp24_pubrev.pdf, all bytes should be
 sent in one shot instead of sending last byte in exception.

This improvment was suggested by Benoit Houyere.

Signed-off-by: Amir Mizinski <amirmizi6@gmail.com>
---
 drivers/char/tpm/tpm_tis_core.c | 72 ++++++++++++++++-------------------------
 1 file changed, 28 insertions(+), 44 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 18b9dc4..c8f4cf8 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -44,9 +44,10 @@ static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
 	return false;
 }
 
-static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask,
-		unsigned long timeout, wait_queue_head_t *queue,
-		bool check_cancel)
+static int wait_for_tpm_stat_result(struct tpm_chip *chip, u8 mask,
+				    u8 mask_result, unsigned long timeout,
+				    wait_queue_head_t *queue,
+				    bool check_cancel)
 {
 	unsigned long stop;
 	long rc;
@@ -55,7 +56,7 @@ static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask,
 
 	/* check current status */
 	status = chip->ops->status(chip);
-	if ((status & mask) == mask)
+	if ((status & mask) == mask_result)
 		return 0;
 
 	stop = jiffies + timeout;
@@ -83,7 +84,7 @@ static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask,
 			usleep_range(TPM_TIMEOUT_USECS_MIN,
 				     TPM_TIMEOUT_USECS_MAX);
 			status = chip->ops->status(chip);
-			if ((status & mask) == mask)
+			if ((status & mask) == mask_result)
 				return 0;
 		} while (time_before(jiffies, stop));
 	}
@@ -290,10 +291,11 @@ static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
 	int size = 0, burstcnt, rc;
 
 	while (size < count) {
-		rc = wait_for_tpm_stat(chip,
-				 TPM_STS_DATA_AVAIL | TPM_STS_VALID,
-				 chip->timeout_c,
-				 &priv->read_queue, true);
+		rc = wait_for_tpm_stat_result(chip,
+					TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+					TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+					chip->timeout_c,
+					&priv->read_queue, true);
 		if (rc < 0)
 			return rc;
 		burstcnt = get_burstcount(chip);
@@ -348,8 +350,9 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 			goto out;
 		}
 
-		if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
-				      &priv->int_queue, false) < 0) {
+		if (wait_for_tpm_stat_result(chip, TPM_STS_VALID,
+					     TPM_STS_VALID, chip->timeout_c,
+					     &priv->int_queue, false) < 0) {
 			size = -ETIME;
 			goto out;
 		}
@@ -385,61 +388,40 @@ static int tpm_tis_send_data(struct tpm_chip *chip, const 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;
 
 	status = tpm_tis_status(chip);
 	if ((status & TPM_STS_COMMAND_READY) == 0) {
 		tpm_tis_ready(chip);
-		if (wait_for_tpm_stat
-		    (chip, TPM_STS_COMMAND_READY, chip->timeout_b,
-		     &priv->int_queue, false) < 0) {
+		if (wait_for_tpm_stat_result(chip, TPM_STS_COMMAND_READY,
+					     TPM_STS_COMMAND_READY,
+					     chip->timeout_b,
+					     &priv->int_queue, false) < 0) {
 			rc = -ETIME;
 			goto out_err;
 		}
 	}
 
-	while (count < len - 1) {
+	while (count < len) {
 		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);
+		burstcnt = min_t(int, burstcnt, len - count);
 		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]);
-	if (rc < 0)
-		goto out_err;
-
-	if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
-				&priv->int_queue, false) < 0) {
+	if (wait_for_tpm_stat_result(chip, TPM_STS_VALID | TPM_STS_DATA_EXPECT,
+				     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;
 
@@ -496,9 +478,11 @@ static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len)
 		ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 
 		dur = tpm_calc_ordinal_duration(chip, ordinal);
-		if (wait_for_tpm_stat
-		    (chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID, dur,
-		     &priv->read_queue, false) < 0) {
+		if (wait_for_tpm_stat_result(chip,
+					     TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+					     TPM_STS_DATA_AVAIL | TPM_STS_VALID,
+					     dur,
+					     &priv->read_queue, false) < 0) {
 			rc = -ETIME;
 			goto out_err;
 		}
-- 
2.7.4


  parent reply	other threads:[~2020-02-10 17:10 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-10 16:28 [PATCH v3 0/7] add tpm i2c ptp driver amirmizi6
2020-02-10 16:28 ` [PATCH v3 1/7] char: tpm: Make implementation of read16 read32 write32 optional amirmizi6
2020-02-12 15:07   ` Jarkko Sakkinen
2020-02-10 16:28 ` [PATCH v3 2/7] char: tpm: Add check_data handle to tpm_tis_phy_ops in order to check data integrity amirmizi6
2020-02-10 16:28 ` [PATCH v3 3/7] char: tpm: rewrite "tpm_tis_req_canceled()" amirmizi6
2020-02-10 16:28 ` amirmizi6 [this message]
2020-02-10 16:28 ` [PATCH v3 5/7] tpm: Handle an exception for TPM Firmware Update mode amirmizi6
2020-02-10 16:28 ` [PATCH v3 6/7] dt-bindings: tpm: Add YAML schema for TPM TIS I2C options amirmizi6
2020-02-12  1:59   ` Rob Herring
2020-02-10 16:28 ` [PATCH v3 7/7] char: tpm: add tpm_tis_i2c driver amirmizi6
2020-02-13 22:56   ` Eddie James

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200210162838.173903-5-amirmizi6@gmail.com \
    --to=amirmizi6@gmail.com \
    --cc=Dan.Morav@nuvoton.com \
    --cc=Eyal.Cohen@nuvoton.com \
    --cc=alexander.steffen@infineon.com \
    --cc=amir.mizinski@nuvoton.com \
    --cc=arnd@arndb.de \
    --cc=devicetree@vger.kernel.org \
    --cc=gcwilson@us.ibm.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=jarkko.sakkinen@linux.intel.com \
    --cc=jgg@ziepe.ca \
    --cc=kgoldman@us.ibm.com \
    --cc=linux-integrity@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=oren.tanami@nuvoton.com \
    --cc=oshri.alkoby@nuvoton.com \
    --cc=oshrialkoby85@gmail.com \
    --cc=peterhuewe@gmx.de \
    --cc=robh+dt@kernel.org \
    --cc=shmulik.hager@nuvoton.com \
    --cc=tmaimon77@gmail.com \
    --subject='Re: [PATCH v3 4/7] char: tpm: Fix expected bit handling and send all bytes in one shot without last byte in exception' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).