diff options
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/tpm/tpm_tis.c | 77 |
1 files changed, 73 insertions, 4 deletions
diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c index 47517e4..ed97cfe 100644 --- a/drivers/char/tpm/tpm_tis.c +++ b/drivers/char/tpm/tpm_tis.c @@ -306,11 +306,10 @@ MODULE_PARM_DESC(itpm, "Force iTPM workarounds (found on some Lenovo laptops)"); * tpm.c can skip polling for the data to be available as the interrupt is * waited for here */ -static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len) +static int tpm_tis_send_data(struct tpm_chip *chip, u8 *buf, size_t len) { int rc, status, burstcnt; size_t count = 0; - u32 ordinal; if (request_locality(chip, 0) < 0) return -EBUSY; @@ -345,8 +344,7 @@ static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len) /* write last byte */ iowrite8(buf[count], - chip->vendor.iobase + - TPM_DATA_FIFO(chip->vendor.locality)); + chip->vendor.iobase + TPM_DATA_FIFO(chip->vendor.locality)); wait_for_stat(chip, TPM_STS_VALID, chip->vendor.timeout_c, &chip->vendor.int_queue); status = tpm_tis_status(chip); @@ -355,6 +353,28 @@ static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len) goto out_err; } + return 0; + +out_err: + tpm_tis_ready(chip); + release_locality(chip, chip->vendor.locality, 0); + return rc; +} + +/* + * If interrupts are used (signaled by an irq set in the vendor structure) + * tpm.c can skip polling for the data to be available as the interrupt is + * waited for here + */ +static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len) +{ + int rc; + u32 ordinal; + + rc = tpm_tis_send_data(chip, buf, len); + if (rc < 0) + return rc; + /* go and do it */ iowrite8(TPM_STS_GO, chip->vendor.iobase + TPM_STS(chip->vendor.locality)); @@ -376,6 +396,47 @@ out_err: return rc; } +/* + * Early probing for iTPM with STS_DATA_EXPECT flaw. + * Try sending command without itpm flag set and if that + * fails, repeat with itpm flag set. + */ +static int probe_itpm(struct tpm_chip *chip) +{ + int rc = 0; + u8 cmd_getticks[] = { + 0x00, 0xc1, 0x00, 0x00, 0x00, 0x0a, + 0x00, 0x00, 0x00, 0xf1 + }; + size_t len = sizeof(cmd_getticks); + int rem_itpm = itpm; + + itpm = 0; + + rc = tpm_tis_send_data(chip, cmd_getticks, len); + if (rc == 0) + goto out; + + tpm_tis_ready(chip); + release_locality(chip, chip->vendor.locality, 0); + + itpm = 1; + + rc = tpm_tis_send_data(chip, cmd_getticks, len); + if (rc == 0) { + dev_info(chip->dev, "Detected an iTPM.\n"); + rc = 1; + } else + rc = -EFAULT; + +out: + itpm = rem_itpm; + tpm_tis_ready(chip); + release_locality(chip, chip->vendor.locality, 0); + + return rc; +} + static const struct file_operations tis_ops = { .owner = THIS_MODULE, .llseek = no_llseek, @@ -515,6 +576,14 @@ static int tpm_tis_init(struct device *dev, resource_size_t start, "1.2 TPM (device-id 0x%X, rev-id %d)\n", vendor >> 16, ioread8(chip->vendor.iobase + TPM_RID(0))); + if (!itpm) { + itpm = probe_itpm(chip); + if (itpm < 0) { + rc = -ENODEV; + goto out_err; + } + } + if (itpm) dev_info(dev, "Intel iTPM workaround enabled\n"); |
