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Diffstat (limited to 'src/drivers/spi/tpm')
-rw-r--r--src/drivers/spi/tpm/tpm.c69
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) {