[PATCH v7 4/5] tpm: Allow TPM chip drivers to override reported command durations
From: Ed Swierk
Date: Mon Jun 20 2016 - 21:59:50 EST
Some TPM chips report bogus command durations in their capabilities,
just as others report incorrect timeouts. Rework tpm_get_timeouts() to
allow chip drivers to override either via a single callback. Also
clean up handling of TPMs that report milliseconds instead of
microseconds.
Signed-off-by: Ed Swierk <eswierk@xxxxxxxxxxxxxxxxxx>
---
drivers/char/tpm/tpm-interface.c | 143 +++++++++++++++++++++------------------
drivers/char/tpm/tpm_tis.c | 35 +++-------
include/linux/tpm.h | 3 +-
3 files changed, 88 insertions(+), 93 deletions(-)
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 73c3ee0..36a6861 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -514,12 +514,11 @@ static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
int tpm_get_timeouts(struct tpm_chip *chip)
{
- cap_t cap;
- unsigned long new_timeout[4];
- unsigned long old_timeout[4];
- ssize_t rc;
+ cap_t cap1, cap2;
+ int rc;
+ struct tpm_vendor_specific orig_vendor;
- rc = tpm_getcap(chip->pdev, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
+ rc = tpm_getcap(chip->pdev, TPM_CAP_PROP_TIS_TIMEOUT, &cap1,
"attempting to determine the timeouts");
if (rc == TPM_ERR_INVALID_POSTINIT) {
/* The TPM is not started, we are the first to talk to it.
@@ -528,77 +527,91 @@ int tpm_get_timeouts(struct tpm_chip *chip)
if (tpm_startup(chip, TPM_ST_CLEAR))
return rc;
- rc = tpm_getcap(chip->pdev, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
+ rc = tpm_getcap(chip->pdev, TPM_CAP_PROP_TIS_TIMEOUT, &cap1,
"attempting to determine the timeouts");
}
if (rc)
return rc;
- old_timeout[0] = be32_to_cpu(cap.timeout.a);
- old_timeout[1] = be32_to_cpu(cap.timeout.b);
- old_timeout[2] = be32_to_cpu(cap.timeout.c);
- old_timeout[3] = be32_to_cpu(cap.timeout.d);
- memcpy(new_timeout, old_timeout, sizeof(new_timeout));
-
- /*
- * Provide ability for vendor overrides of timeout values in case
- * of misreporting.
- */
- if (chip->ops->update_timeouts != NULL)
- chip->vendor.timeout_adjusted =
- chip->ops->update_timeouts(chip, new_timeout);
-
- if (!chip->vendor.timeout_adjusted) {
- /* Don't overwrite default if value is 0 */
- if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
- int i;
-
- /* timeouts in msec rather usec */
- for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
- new_timeout[i] *= 1000;
- chip->vendor.timeout_adjusted = true;
- }
- }
-
- /* Report adjusted timeouts */
- if (chip->vendor.timeout_adjusted) {
- dev_info(chip->pdev,
- HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
- old_timeout[0], new_timeout[0],
- old_timeout[1], new_timeout[1],
- old_timeout[2], new_timeout[2],
- old_timeout[3], new_timeout[3]);
- }
-
- chip->vendor.timeout_a = usecs_to_jiffies(new_timeout[0]);
- chip->vendor.timeout_b = usecs_to_jiffies(new_timeout[1]);
- chip->vendor.timeout_c = usecs_to_jiffies(new_timeout[2]);
- chip->vendor.timeout_d = usecs_to_jiffies(new_timeout[3]);
-
- rc = tpm_getcap(chip->pdev, TPM_CAP_PROP_TIS_DURATION, &cap,
+ rc = tpm_getcap(chip->pdev, TPM_CAP_PROP_TIS_DURATION, &cap2,
"attempting to determine the durations");
if (rc)
return rc;
- chip->vendor.duration[TPM_SHORT] =
- usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_short));
- chip->vendor.duration[TPM_MEDIUM] =
- usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_medium));
- chip->vendor.duration[TPM_LONG] =
- usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_long));
+ be32_to_cpus(&cap1.timeout.a);
+ be32_to_cpus(&cap1.timeout.b);
+ be32_to_cpus(&cap1.timeout.c);
+ be32_to_cpus(&cap1.timeout.d);
+ chip->vendor.timeout_a = usecs_to_jiffies(cap1.timeout.a);
+ chip->vendor.timeout_b = usecs_to_jiffies(cap1.timeout.b);
+ chip->vendor.timeout_c = usecs_to_jiffies(cap1.timeout.c);
+ chip->vendor.timeout_d = usecs_to_jiffies(cap1.timeout.d);
- /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
- * value wrong and apparently reports msecs rather than usecs. So we
- * fix up the resulting too-small TPM_SHORT value to make things work.
- * We also scale the TPM_MEDIUM and -_LONG values by 1000.
- */
- if (chip->vendor.duration[TPM_SHORT] < (HZ / 100)) {
- chip->vendor.duration[TPM_SHORT] = HZ;
- chip->vendor.duration[TPM_MEDIUM] *= 1000;
- chip->vendor.duration[TPM_LONG] *= 1000;
- chip->vendor.duration_adjusted = true;
- dev_info(chip->pdev, "Adjusting TPM timeout parameters.");
+ /* Some TPMs report timeouts in milliseconds rather than
+ microseconds. Use a value between 1 and 1000 as an
+ indication that this is the case. */
+ if (cap1.timeout.a > 0 && cap1.timeout.a < 1000) {
+ chip->vendor.timeout_a = msecs_to_jiffies(cap1.timeout.a);
+ chip->vendor.timeout_b = msecs_to_jiffies(cap1.timeout.b);
+ chip->vendor.timeout_c = msecs_to_jiffies(cap1.timeout.c);
+ chip->vendor.timeout_d = msecs_to_jiffies(cap1.timeout.d);
+ chip->vendor.timeout_adjusted = true;
}
+
+ be32_to_cpus(&cap2.duration.tpm_short);
+ be32_to_cpus(&cap2.duration.tpm_medium);
+ be32_to_cpus(&cap2.duration.tpm_long);
+ chip->vendor.duration[TPM_SHORT] =
+ usecs_to_jiffies(cap2.duration.tpm_short);
+ chip->vendor.duration[TPM_MEDIUM] =
+ usecs_to_jiffies(cap2.duration.tpm_medium);
+ chip->vendor.duration[TPM_LONG] =
+ usecs_to_jiffies(cap2.duration.tpm_long);
+
+ memcpy(&orig_vendor, &chip->vendor, sizeof(orig_vendor));
+
+ /* Interpret duration values between 1 and 10000 as
+ milliseconds to deal with TPMs like the Broadcom BCM0102 in
+ the Dell Latitude D820. */
+ if (cap2.duration.tpm_short > 0 && cap2.duration.tpm_short < 10000) {
+ chip->vendor.duration[TPM_SHORT] =
+ msecs_to_jiffies(cap2.duration.tpm_short);
+ chip->vendor.duration[TPM_MEDIUM] =
+ msecs_to_jiffies(cap2.duration.tpm_medium);
+ chip->vendor.duration[TPM_LONG] =
+ msecs_to_jiffies(cap2.duration.tpm_long);
+ chip->vendor.duration_adjusted = true;
+ }
+
+ if (chip->ops->update_timeouts != NULL)
+ chip->ops->update_timeouts(chip);
+
+ if (chip->vendor.timeout_adjusted) {
+ dev_info(chip->pdev,
+ HW_ERR "Adjusted timeouts: A %u->%uus B %u->%uus"
+ " C %u->%uus D %u->%uus\n",
+ jiffies_to_usecs(orig_vendor.timeout_a),
+ jiffies_to_usecs(chip->vendor.timeout_a),
+ jiffies_to_usecs(orig_vendor.timeout_b),
+ jiffies_to_usecs(chip->vendor.timeout_b),
+ jiffies_to_usecs(orig_vendor.timeout_c),
+ jiffies_to_usecs(chip->vendor.timeout_c),
+ jiffies_to_usecs(orig_vendor.timeout_d),
+ jiffies_to_usecs(chip->vendor.timeout_d));
+ }
+
+ if (chip->vendor.duration_adjusted) {
+ dev_info(chip->pdev,
+ HW_ERR "Adjusted durations: short %u->%uus"
+ " medium %u->%uus long %u->%uus\n",
+ jiffies_to_usecs(orig_vendor.duration[TPM_SHORT]),
+ jiffies_to_usecs(chip->vendor.duration[TPM_SHORT]),
+ jiffies_to_usecs(orig_vendor.duration[TPM_MEDIUM]),
+ jiffies_to_usecs(chip->vendor.duration[TPM_MEDIUM]),
+ jiffies_to_usecs(orig_vendor.duration[TPM_LONG]),
+ jiffies_to_usecs(chip->vendor.duration[TPM_LONG]));
+ }
+
return 0;
}
EXPORT_SYMBOL_GPL(tpm_get_timeouts);
diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index 088fa86..caf7278 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -475,34 +475,17 @@ static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
return rc;
}
-struct tis_vendor_timeout_override {
- u32 did_vid;
- unsigned long timeout_us[4];
-};
-
-static const struct tis_vendor_timeout_override vendor_timeout_overrides[] = {
- /* Atmel 3204 */
- { 0x32041114, { (TIS_SHORT_TIMEOUT*1000), (TIS_LONG_TIMEOUT*1000),
- (TIS_SHORT_TIMEOUT*1000), (TIS_SHORT_TIMEOUT*1000) } },
-};
-
-static bool tpm_tis_update_timeouts(struct tpm_chip *chip,
- unsigned long *timeout_cap)
+static void tpm_tis_update_timeouts(struct tpm_chip *chip)
{
- int i;
- u32 did_vid;
-
- did_vid = ioread32(chip->vendor.iobase + TPM_DID_VID(0));
-
- for (i = 0; i != ARRAY_SIZE(vendor_timeout_overrides); i++) {
- if (vendor_timeout_overrides[i].did_vid != did_vid)
- continue;
- memcpy(timeout_cap, vendor_timeout_overrides[i].timeout_us,
- sizeof(vendor_timeout_overrides[i].timeout_us));
- return true;
+ switch (ioread32(chip->vendor.iobase + TPM_DID_VID(0))) {
+ case 0x32041114: /* Atmel 3204 */
+ chip->vendor.timeout_a = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
+ chip->vendor.timeout_b = msecs_to_jiffies(TIS_LONG_TIMEOUT);
+ chip->vendor.timeout_c = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
+ chip->vendor.timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
+ chip->vendor.timeout_adjusted = true;
+ break;
}
-
- return false;
}
/*
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index 706e63e..2380ebf 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -41,8 +41,7 @@ struct tpm_class_ops {
int (*send) (struct tpm_chip *chip, u8 *buf, size_t len);
void (*cancel) (struct tpm_chip *chip);
u8 (*status) (struct tpm_chip *chip);
- bool (*update_timeouts)(struct tpm_chip *chip,
- unsigned long *timeout_cap);
+ void (*update_timeouts)(struct tpm_chip *chip);
};
--
1.9.1