[PATCH 3/3 v3] tpm_tis: override durations for STM tpm with firmware 1.2.8.28

[Jerry Snitselaar]

There was revealed a bug in the STM TPM chipset used in Dell R415s.
Bug is observed so far only on chipset firmware 1.2.8.28
(1.2 TPM, device-id 0x0, rev-id 78). After some number of
operations chipset hangs and stays in inconsistent state:

tpm_tis 00:09: Operation Timed out
tpm_tis 00:09: tpm_transmit: tpm_send: error -5

Durations returned by the chip are the same like on other
firmware revisions but apparently with specifically 1.2.8.28 fw
durations should be reset to 2 minutes to enable tpm chip work
properly. No working way of updating firmware was found.

This patch adds implementation of ->update_durations method
that matches only STM devices with specific firmware version.

Cc: Peter Huewe <peterhuewe@xxxxxx>
Cc: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxx>
Signed-off-by: Alexey Klimov <aklimov@xxxxxxxxxx>
Signed-off-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
---
v3: Rework update_durations to make use of new version structs
    from 1/3 patch, and move tpm1_getcap calls out of the loop.
v2: Make suggested changes from Jarkko
    - change struct field name to durations from durs
    - formatting cleanups
    - turn into void function like update_timeouts and
      use chip->duration_adjusted to track whether adjustment occurred.

 drivers/char/tpm/tpm_tis_core.c | 79 +++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index c3181ea9f271..27c6ca031e23 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -506,6 +506,84 @@ static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
 	return rc;
 }
 
+struct tis_vendor_durations_override {
+	u32 did_vid;
+	struct tpm1_version version;
+	unsigned long durations[3];
+};
+
+static const struct  tis_vendor_durations_override vendor_dur_overrides[] = {
+	/* STMicroelectronics 0x104a */
+	{ 0x0000104a,
+	  { 1, 2, 8, 28 },
+	  { (2 * 60 * HZ), (2 * 60 * HZ), (2 * 60 * HZ) } },
+};
+
+static void tpm_tis_update_durations(struct tpm_chip *chip,
+				     unsigned long *duration_cap)
+{
+	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
+	struct tpm1_version *version;
+	u32 did_vid;
+	int i, rc;
+	cap_t cap;
+
+	chip->duration_adjusted = false;
+
+	if (chip->ops->clk_enable != NULL)
+		chip->ops->clk_enable(chip, true);
+
+	rc = tpm_tis_read32(priv, TPM_DID_VID(0), &did_vid);
+	if (rc < 0) {
+		dev_warn(&chip->dev, "%s: failed to read did_vid. %d\n",
+			 __func__, rc);
+		goto out;
+	}
+
+	/* Try to get a TPM version 1.2 or 1.1 TPM_CAP_VERSION_INFO */
+	rc = tpm1_getcap(chip, TPM_CAP_VERSION_1_2, &cap,
+			 "attempting to determine the 1.2 version",
+			 sizeof(cap.version2));
+	if (!rc) {
+		version = &cap.version2.version;
+	} else {
+		rc = tpm1_getcap(chip, TPM_CAP_VERSION_1_1, &cap,
+				 "attempting to determine the 1.1 version",
+				 sizeof(cap.version1));
+
+		if (rc)
+			goto out;
+
+		version = &cap.version1;
+	}
+
+	for (i = 0; i != ARRAY_SIZE(vendor_dur_overrides); i++) {
+		if (vendor_dur_overrides[i].did_vid != did_vid)
+			continue;
+
+		if ((version->major ==
+		     vendor_dur_overrides[i].version.major) &&
+		    (version->minor ==
+		     vendor_dur_overrides[i].version.minor) &&
+		    (version->rev_major ==
+		     vendor_dur_overrides[i].version.rev_major) &&
+		    (version->rev_minor ==
+		     vendor_dur_overrides[i].version.rev_minor)) {
+
+			memcpy(duration_cap,
+			       vendor_dur_overrides[i].durations,
+			       sizeof(vendor_dur_overrides[i].durations));
+
+			chip->duration_adjusted = true;
+			goto out;
+		}
+	}
+
+out:
+	if (chip->ops->clk_enable != NULL)
+		chip->ops->clk_enable(chip, false);
+}
+
 struct tis_vendor_timeout_override {
 	u32 did_vid;
 	unsigned long timeout_us[4];
@@ -842,6 +920,7 @@ static const struct tpm_class_ops tpm_tis = {
 	.send = tpm_tis_send,
 	.cancel = tpm_tis_ready,
 	.update_timeouts = tpm_tis_update_timeouts,
+	.update_durations = tpm_tis_update_durations,
 	.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,
-- 
2.21.0