security/tpm/: turn tis_{init,open} into tis_probe

init() was always followed by open() and after successful initialization
we only need send-receive function which is now returned by tis_probe()
on success, thus further reducing number of functions to export from
drivers.

This also removes check for opening TIS twice that seems to have no
value.

Change-Id: I52ad8d69d50d449f031c36b15bf70ef07986946c
Ticket: https://ticket.coreboot.org/issues/433
Signed-off-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/76954
Reviewed-by: Julius Werner <jwerner@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 19 insertions, 17 deletions

diff --git a/src/security/tpm/tss/tcg-1.2/tss.c b/src/security/tpm/tss/tcg-1.2/tss.c
index e73db388e8..f0d28dfe3f 100644
--- a/src/security/tpm/tss/tcg-1.2/tss.c
+++ b/src/security/tpm/tss/tcg-1.2/tss.c
@@ -24,13 +24,22 @@
 #include <console/console.h>
 #define VBDEBUG(format, args...) printk(BIOS_DEBUG, format, ## args)
 
+static tis_sendrecv_fn tis_sendrecv;
+
 static tpm_result_t tpm_send_receive(const uint8_t *request,
-				uint32_t request_length,
-				uint8_t *response,
-				uint32_t *response_length)
+				     uint32_t request_length,
+				     uint8_t *response,
+				     uint32_t *response_length)
 {
 	size_t len = *response_length;
-	tpm_result_t rc = tis_sendrecv(request, request_length, response, &len);
+	tpm_result_t rc;
+
+	if (tis_sendrecv == NULL) {
+		printk(BIOS_ERR, "Attempted use of uninitialized TSS 1.2 stack\n");
+		return TPM_FAIL;
+	}
+
+	rc = tis_sendrecv(request, request_length, response, &len);
 	if (rc)
 		return rc;
 	/* check 64->32bit overflow and (re)check response buffer overflow */
@@ -142,23 +151,16 @@ static tpm_result_t send(const uint8_t *command)
 
 /* Exported functions. */
 
-static uint8_t tlcl_init_done;
-
 tpm_result_t tlcl_lib_init(void)
 {
-	tpm_result_t rc = TPM_SUCCESS;
-	if (tlcl_init_done)
-		return rc;
-	rc = tis_init();
-	if (rc)
-		return rc;
-	rc = tis_open();
-	if (rc)
-		return rc;
+	if (tis_sendrecv != NULL)
+		return TPM_SUCCESS;
 
-	tlcl_init_done = 1;
+	tis_sendrecv = tis_probe();
+	if (tis_sendrecv == NULL)
+		return TPM_CB_NO_DEVICE;
 
-	return rc;
+	return TPM_SUCCESS;
 }
 
 tpm_result_t tlcl_startup(void)