drm/amd/display: HDCP Locality check using DMUB Fused IO

[Why]
HDCP locality check has strict timing requirements, currently broken
due to reliance on msleep which does not guarantee accuracy.
The PR moves the write-poll-read sequence into DMUB using new generic
Fused IO interface, where the timing accuracy is greatly improved.
New flow is enabled using DCN resource capability bit (none for now),
or using a debug flag.

[How]
* Extended mod_hdcp_config with new function for requesting DMUB
to execute a sequence of fused I2C/AUX commands and synchronously
wait until an outbox reply arrives or a timeout expires.
* If the timeout expires, send an abort to DMUB.
* Update HDCP to use the DMUB for locality check if supported.
* Add DC_HDCP_LC_FORCE_FW_ENABLE and DC_HDCP_LC_ENABLE_SW_FALLBACK.
* Make the first enable new flow regardless of resource capabilities.
* Make the second enable fallback to old SW flow.
* Clean up makefile source file listings for easier updates.

Reviewed-by: Alvin Lee <[email protected]>
Signed-off-by: Dominik Kaszewski <[email protected]>
Signed-off-by: Roman Li <[email protected]>
Tested-by: Daniel Wheeler <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

1 files changed, 36 insertions, 12 deletions

diff --git a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp2_transition.c b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp2_transition.c
index c5f6c11de7e5..89ffb89e1932 100644
--- a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp2_transition.c
+++ b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp2_transition.c
@@ -184,17 +184,28 @@ enum mod_hdcp_status mod_hdcp_hdcp2_transition(struct mod_hdcp *hdcp,
 		callback_in_ms(0, output);
 		set_state_id(hdcp, output, H2_A2_LOCALITY_CHECK);
 		break;
-	case H2_A2_LOCALITY_CHECK:
+	case H2_A2_LOCALITY_CHECK: {
+		const bool use_fw = hdcp->config.ddc.funcs.atomic_write_poll_read_i2c
+				&& !adjust->hdcp2.force_sw_locality_check;
+
+		/*
+		 * 1A-05: consider disconnection after LC init a failure
+		 * 1A-13-1: consider invalid l' a failure
+		 * 1A-13-2: consider l' timeout a failure
+		 */
 		if (hdcp->state.stay_count > 10 ||
 				input->lc_init_prepare != PASS ||
-				input->lc_init_write != PASS ||
-				input->l_prime_available_poll != PASS ||
-				input->l_prime_read != PASS) {
-			/*
-			 * 1A-05: consider disconnection after LC init a failure
-			 * 1A-13-1: consider invalid l' a failure
-			 * 1A-13-2: consider l' timeout a failure
-			 */
+				(!use_fw && input->lc_init_write != PASS) ||
+				(!use_fw && input->l_prime_available_poll != PASS)) {
+			fail_and_restart_in_ms(0, &status, output);
+			break;
+		} else if (input->l_prime_read != PASS) {
+			if (use_fw && hdcp->config.debug.lc_enable_sw_fallback) {
+				adjust->hdcp2.force_sw_locality_check = true;
+				callback_in_ms(0, output);
+				break;
+			}
+
 			fail_and_restart_in_ms(0, &status, output);
 			break;
 		} else if (input->l_prime_validation != PASS) {
@@ -205,6 +216,7 @@ enum mod_hdcp_status mod_hdcp_hdcp2_transition(struct mod_hdcp *hdcp,
 		callback_in_ms(0, output);
 		set_state_id(hdcp, output, H2_A3_EXCHANGE_KS_AND_TEST_FOR_REPEATER);
 		break;
+	}
 	case H2_A3_EXCHANGE_KS_AND_TEST_FOR_REPEATER:
 		if (input->eks_prepare != PASS ||
 				input->eks_write != PASS) {
@@ -498,14 +510,25 @@ enum mod_hdcp_status mod_hdcp_hdcp2_dp_transition(struct mod_hdcp *hdcp,
 		callback_in_ms(0, output);
 		set_state_id(hdcp, output, D2_A2_LOCALITY_CHECK);
 		break;
-	case D2_A2_LOCALITY_CHECK:
+	case D2_A2_LOCALITY_CHECK: {
+		const bool use_fw = hdcp->config.ddc.funcs.atomic_write_poll_read_aux
+				&& !adjust->hdcp2.force_sw_locality_check;
+
 		if (hdcp->state.stay_count > 10 ||
 				input->lc_init_prepare != PASS ||
-				input->lc_init_write != PASS ||
-				input->l_prime_read != PASS) {
+				(!use_fw && input->lc_init_write != PASS)) {
 			/* 1A-12: consider invalid l' a failure */
 			fail_and_restart_in_ms(0, &status, output);
 			break;
+		} else if (input->l_prime_read != PASS) {
+			if (use_fw && hdcp->config.debug.lc_enable_sw_fallback) {
+				adjust->hdcp2.force_sw_locality_check = true;
+				callback_in_ms(0, output);
+				break;
+			}
+
+			fail_and_restart_in_ms(0, &status, output);
+			break;
 		} else if (input->l_prime_validation != PASS) {
 			callback_in_ms(0, output);
 			increment_stay_counter(hdcp);
@@ -514,6 +537,7 @@ enum mod_hdcp_status mod_hdcp_hdcp2_dp_transition(struct mod_hdcp *hdcp,
 		callback_in_ms(0, output);
 		set_state_id(hdcp, output, D2_A34_EXCHANGE_KS_AND_TEST_FOR_REPEATER);
 		break;
+	}
 	case D2_A34_EXCHANGE_KS_AND_TEST_FOR_REPEATER:
 		if (input->eks_prepare != PASS ||
 				input->eks_write != PASS) {