Hi Ilias,
On Thu, 26 Jan 2023 at 01:18, Ilias Apalodimas ilias.apalodimas@linaro.org wrote:
As described in [0] if a command requires use of an untested algorithm or functional module, the TPM performs the test and then completes the command actions.
Since we don't check for TPM_RC_NEEDS_TEST (which is the return code of the TPM in that case) and even if we would, it would complicate our TPM code for no apparent reason, add a wrapper function that performs both the selftest and the startup sequence of the TPM.
It's worth noting that this is implemented on TPMv2.0. The code for 1.2 would look similar, but I don't have a device available to test.
[0] https://trustedcomputinggroup.org/wp-content/uploads/TPM-Rev-2.0-Part-1-Arch... ยง12.3 Self-test modes
Signed-off-by: Ilias Apalodimas ilias.apalodimas@linaro.org
Changes since v2:
- add tpm_init() to auto start
Changes since v1:
- Remove a superfluous if statement
- Move function comments to the header file
include/tpm-v2.h | 19 +++++++++++++++++++ include/tpm_api.h | 8 ++++++++ lib/tpm-v2.c | 24 ++++++++++++++++++++++++ lib/tpm_api.c | 8 ++++++++ 4 files changed, 59 insertions(+)
I think this is a good idea, but it should be implemented at the API level. Please see below.
diff --git a/include/tpm-v2.h b/include/tpm-v2.h index 737e57551d73..1c644f0048f6 100644 --- a/include/tpm-v2.h +++ b/include/tpm-v2.h @@ -688,4 +688,23 @@ u32 tpm2_report_state(struct udevice *dev, uint vendor_cmd, uint vendor_subcmd, u32 tpm2_enable_nvcommits(struct udevice *dev, uint vendor_cmd, uint vendor_subcmd);
+/**
- tpm2_auto_start() - start up the TPM and perform selftests.
If a testable function has not been tested and is
requested the TPM2 will return TPM_RC_NEEDS_TEST.
drop extra lines
- @param dev TPM device
- Return: TPM2_RC_TESTING, if TPM2 self-test has been received and the tests are
80 cols
not complete.
TPM2_RC_SUCCESS, if testing of all functions is complete without
functional failures.
TPM2_RC_FAILURE, if any test failed.
TPM2_RC_INITIALIZE, if the TPM has not gone through the Startup
sequence- */
+u32 tpm2_auto_start(struct udevice *dev);
#endif /* __TPM_V2_H */ diff --git a/include/tpm_api.h b/include/tpm_api.h index 8979d9d6df7e..022a8bbaeca6 100644 --- a/include/tpm_api.h +++ b/include/tpm_api.h @@ -331,4 +331,12 @@ static inline bool tpm_is_v2(struct udevice *dev) return IS_ENABLED(CONFIG_TPM_V2) && tpm_get_version(dev) == TPM_V2; }
+/**
- tpm_auto_start() - start up the TPM and perform selftests
- @param dev TPM device
- Return: return code of the operation (0 = success)
- */
+u32 tpm_auto_start(struct udevice *dev);
#endif /* __TPM_API_H */ diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c index 697b982e079f..2141d58632ff 100644 --- a/lib/tpm-v2.c +++ b/lib/tpm-v2.c @@ -44,6 +44,30 @@ u32 tpm2_self_test(struct udevice *dev, enum tpm2_yes_no full_test) return tpm_sendrecv_command(dev, command_v2, NULL, NULL); }
+u32 tpm2_auto_start(struct udevice *dev) +{
u32 rc;/** the tpm_init() will return -EBUSY if the init has already happened* The selftest and startup code can run multiple times with no side effects
80 cols
*/rc = tpm_init(dev);if (rc && rc != -EBUSY)
Does that work, with rc being unsigned?
return rc;rc = tpm2_self_test(dev, TPMI_YES);
Can we call tpm_self_test_full() ? If not, please update the API as needed.
if (rc == TPM2_RC_INITIALIZE) {rc = tpm2_startup(dev, TPM2_SU_CLEAR);
Should call tpm_startup()
if (rc)return rc;rc = tpm2_self_test(dev, TPMI_YES);
Again, tpm_self_test_full(). We are trying to provide a TPM API that covers v1 and v2, to the extent possible.
}return rc;+}
Also please add a test for this to test/dm/tpm.c
u32 tpm2_clear(struct udevice *dev, u32 handle, const char *pw, const ssize_t pw_sz) { diff --git a/lib/tpm_api.c b/lib/tpm_api.c index 7e8df8795ef3..5b2c11a277cc 100644 --- a/lib/tpm_api.c +++ b/lib/tpm_api.c @@ -35,6 +35,14 @@ u32 tpm_startup(struct udevice *dev, enum tpm_startup_type mode) } }
+u32 tpm_auto_start(struct udevice *dev) +{
if (tpm_is_v2(dev))return tpm2_auto_start(dev);
Hopefully all the code from above can move here.
return -ENOSYS;+}
u32 tpm_resume(struct udevice *dev) { if (tpm_is_v1(dev)) -- 2.38.1
Regards, Simon