From: Amir Mizinski <[email protected]> Detected the following incorrect implementation of the send command: polling on the TPM_STS.stsValid field followed by checking the TPM_STS.expect field only once. Since TPM_STS.stsValid represents the TPM_STS.expect validity, both fields should be polled at the same time.
This fix modifies the signature of wait_for_tpm_stat(), adding an additional "mask_result" parameter to its call. wait_for_tpm_stat() is now polling the TPM_STS with a mask and waits for the value in mask_result. The fix adds the ability to check if certain TPM_STS bits have been cleared. This change is also aligned to verifying the CRC on I2C TPM. The CRC verification should be done after the TPM_STS.expect field is cleared (TPM received all expected command bytes and set the calculated CRC value in the register). In addition, the send command was changed to comply with TCG_DesignPrinciples_TPM2p0Driver_vp24_pubrev.pdf as follows: - send all command bytes in one loop - remove special handling of the last byte Suggested-by: Benoit Houyere <[email protected]> Signed-off-by: Amir Mizinski <[email protected]> --- drivers/char/tpm/tpm_tis_core.c | 66 ++++++++++++++--------------------------- 1 file changed, 22 insertions(+), 44 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index 27c6ca0..d276f03 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -44,9 +44,9 @@ 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(struct tpm_chip *chip, u8 mask, u8 stat, + unsigned long timeout, wait_queue_head_t *queue, + bool check_cancel) { unsigned long stop; long rc; @@ -55,7 +55,7 @@ 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) == stat) return 0; stop = jiffies + timeout; @@ -83,7 +83,7 @@ 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) == stat) return 0; } while (time_before(jiffies, stop)); } @@ -281,10 +281,10 @@ 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(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); @@ -337,8 +337,8 @@ 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(chip, TPM_STS_VALID, TPM_STS_VALID, + chip->timeout_c, &priv->int_queue, false) < 0) { size = -ETIME; goto out; } @@ -364,61 +364,39 @@ 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(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(chip, TPM_STS_VALID | TPM_STS_DATA_EXPECT, + TPM_STS_VALID, chip->timeout_a, &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; @@ -470,9 +448,9 @@ 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(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
