diff options
| -rw-r--r-- | src/drivers/spi/tpm/tpm.c | 69 |
1 files changed, 42 insertions, 27 deletions
diff --git a/src/drivers/spi/tpm/tpm.c b/src/drivers/spi/tpm/tpm.c index c09462e783..356c0fe3f7 100644 --- a/src/drivers/spi/tpm/tpm.c +++ b/src/drivers/spi/tpm/tpm.c @@ -346,37 +346,48 @@ static int tpm2_claim_locality(void) uint8_t access; struct stopwatch sw; - access = tpm2_read_access_reg(); /* - * If active locality is set (maybe reset line is not connected?), - * release the locality and try again. + * Locality is released by TPM reset. + * + * If locality is taken at this point, this could be due to the fact + * that the TPM is performing a long operation and has not processed + * reset request yet. We'll wait up to CR50_TIMEOUT_INIT_MS and see if + * it releases locality when reset is processed. */ - if (access & TPM_ACCESS_ACTIVE_LOCALITY) { - tpm2_write_access_reg(TPM_ACCESS_ACTIVE_LOCALITY); + stopwatch_init_msecs_expire(&sw, CR50_TIMEOUT_INIT_MS); + do { access = tpm2_read_access_reg(); - } + if (access & TPM_ACCESS_ACTIVE_LOCALITY) { + /* + * Don't bombard the chip with traffic, let it keep + * processing the command. + */ + mdelay(2); + continue; + } - /* - * If cr50 is doing a long crypto operation, it can take up to - * 30 seconds to get a valid status value back - */ - stopwatch_init_msecs_expire(&sw, CR50_TIMEOUT_INIT_MS); - while (!stopwatch_expired(&sw) && access != TPM_ACCESS_VALID) + /* + * Ok, the locality is free, TPM must be reset, let's claim + * it. + */ + + tpm2_write_access_reg(TPM_ACCESS_REQUEST_USE); access = tpm2_read_access_reg(); - if (access != TPM_ACCESS_VALID) { - printk(BIOS_ERR, "Invalid reset status: %#x\n", access); - return 0; - } + if (access != (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY)) { + break; + } - tpm2_write_access_reg(TPM_ACCESS_REQUEST_USE); - access = tpm2_read_access_reg(); - if (access != (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY)) { - printk(BIOS_ERR, "Failed to claim locality 0, status: %#x\n", - access); - return 0; - } + printk(BIOS_INFO, "TPM ready after %ld ms\n", + stopwatch_duration_msecs(&sw)); - return 1; + return 1; + } while (!stopwatch_expired(&sw)); + + printk(BIOS_ERR, + "Failed to claim locality 0 after %ld ms, status: %#x\n", + stopwatch_duration_msecs(&sw), access); + + return 0; } /* Device/vendor ID values of the TPM devices this driver supports. */ @@ -426,9 +437,13 @@ int tpm2_init(struct spi_slave *spi_if) printk(BIOS_INFO, " done!\n"); - /* Claim locality 0. */ - if (!tpm2_claim_locality()) - return -1; + if (ENV_VERSTAGE || ENV_BOOTBLOCK) + /* + * Claim locality 0, do it only during the first + * initialization after reset. + */ + if (!tpm2_claim_locality()) + return -1; read_tpm_sts(&status); if ((status & TPM_STS_FAMILY_MASK) != TPM_STS_FAMILY_TPM_2_0) { |