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| author | Stefan Mahnke-Hartmann <stefan.mahnke-hartmann@infineon.com> | 2022-06-03 10:41:58 +0200 |
|---|---|---|
| committer | Jarkko Sakkinen <jarkko@kernel.org> | 2022-08-03 23:56:19 +0300 |
| commit | 5e3a3f27cbded417e6d1ea2bb9739b572c09580e (patch) | |
| tree | cecaa173565ccfad09d852989a2477d9d23fbbcf /drivers/char/tpm | |
| parent | 200e340f2196d7fd427a5810d06e893b932f145a (diff) | |
| download | linux-5e3a3f27cbded417e6d1ea2bb9739b572c09580e.tar.gz | |
tpm: Add upgrade/reduced mode support for TPM1.2 modules
In case a TPM in failure mode is detected, the TPM should be accessible
through a transparent communication channel for analysing purposes (e.g.
TPM_GetTestResult) or a field upgrade. Since a TPM in failure mode has
similar reduced functionality as in field upgrade mode, the flag
TPM_CHIP_FLAG_FIRMWARE_UPGRADE is also valid.
As described in TCG TPM Main Part1 Design Principles, Revision 116,
chapter 9.2.1. the TPM also allows an update function in case a TPM is
in failure mode.
If the TPM in failure mode is detected, the function tpm1_auto_startup()
sets TPM_CHIP_FLAG_FIRMWARE_UPGRADE flag, which is used later during
driver initialization/deinitialization to disable functionality which
makes no sense or will fail in the current TPM state. The following
functionality is affected:
* Do not register TPM as a hwrng
* Do not get pcr allocation
* Do not register sysfs entries which provide information impossible to
obtain in limited mode
Signed-off-by: Stefan Mahnke-Hartmann <stefan.mahnke-hartmann@infineon.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Diffstat (limited to 'drivers/char/tpm')
| -rw-r--r-- | drivers/char/tpm/tpm.h | 1 | ||||
| -rw-r--r-- | drivers/char/tpm/tpm1-cmd.c | 7 |
2 files changed, 7 insertions, 1 deletions
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 2163c6ee0d364..24ee4e1cc452a 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -55,6 +55,7 @@ enum tpm_addr { #define TPM_WARN_DOING_SELFTEST 0x802 #define TPM_ERR_DEACTIVATED 0x6 #define TPM_ERR_DISABLED 0x7 +#define TPM_ERR_FAILEDSELFTEST 0x1C #define TPM_ERR_INVALID_POSTINIT 38 #define TPM_TAG_RQU_COMMAND 193 diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c index f7dc986fa4a0a..cf64c73851052 100644 --- a/drivers/char/tpm/tpm1-cmd.c +++ b/drivers/char/tpm/tpm1-cmd.c @@ -709,7 +709,12 @@ int tpm1_auto_startup(struct tpm_chip *chip) if (rc) goto out; rc = tpm1_do_selftest(chip); - if (rc) { + if (rc == TPM_ERR_FAILEDSELFTEST) { + dev_warn(&chip->dev, "TPM self test failed, switching to the firmware upgrade mode\n"); + /* A TPM in this state possibly allows or needs a firmware upgrade */ + chip->flags |= TPM_CHIP_FLAG_FIRMWARE_UPGRADE; + return 0; + } else if (rc) { dev_err(&chip->dev, "TPM self test failed\n"); goto out; } |