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 <alvin.lee2@amd.com>
Signed-off-by: Dominik Kaszewski <dominik.kaszewski@amd.com>
Signed-off-by: Roman Li <roman.li@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

5 files changed, 189 insertions, 24 deletions

diff --git a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp.h b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp.h
index 55c7d873175f..a37634942b07 100644
--- a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp.h
+++ b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp.h
@@ -386,6 +386,7 @@ enum mod_hdcp_status mod_hdcp_write_repeater_auth_ack(struct mod_hdcp *hdcp);
 enum mod_hdcp_status mod_hdcp_write_stream_manage(struct mod_hdcp *hdcp);
 enum mod_hdcp_status mod_hdcp_write_content_type(struct mod_hdcp *hdcp);
 enum mod_hdcp_status mod_hdcp_clear_cp_irq_status(struct mod_hdcp *hdcp);
+enum mod_hdcp_status mod_hdcp_write_poll_read_lc_fw(struct mod_hdcp *hdcp);
 
 /* hdcp version helpers */
 static inline uint8_t is_dp_hdcp(struct mod_hdcp *hdcp)
diff --git a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp2_execution.c b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp2_execution.c
index 1d41dd58f6bc..bb8ae80b37f8 100644
--- a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp2_execution.c
+++ b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp2_execution.c
@@ -452,21 +452,12 @@ out:
 	return status;
 }
 
-static enum mod_hdcp_status locality_check(struct mod_hdcp *hdcp,
+static enum mod_hdcp_status locality_check_sw(struct mod_hdcp *hdcp,
 		struct mod_hdcp_event_context *event_ctx,
 		struct mod_hdcp_transition_input_hdcp2 *input)
 {
 	enum mod_hdcp_status status = MOD_HDCP_STATUS_SUCCESS;
 
-	if (event_ctx->event != MOD_HDCP_EVENT_CALLBACK) {
-		event_ctx->unexpected_event = 1;
-		goto out;
-	}
-
-	if (!mod_hdcp_execute_and_set(mod_hdcp_hdcp2_prepare_lc_init,
-			&input->lc_init_prepare, &status,
-			hdcp, "lc_init_prepare"))
-		goto out;
 	if (!mod_hdcp_execute_and_set(mod_hdcp_write_lc_init,
 			&input->lc_init_write, &status,
 			 hdcp, "lc_init_write"))
@@ -482,6 +473,48 @@ static enum mod_hdcp_status locality_check(struct mod_hdcp *hdcp,
 			&input->l_prime_read, &status,
 			hdcp, "l_prime_read"))
 		goto out;
+out:
+	return status;
+}
+
+static enum mod_hdcp_status locality_check_fw(struct mod_hdcp *hdcp,
+		struct mod_hdcp_event_context *event_ctx,
+		struct mod_hdcp_transition_input_hdcp2 *input)
+{
+	enum mod_hdcp_status status = MOD_HDCP_STATUS_SUCCESS;
+
+	if (!mod_hdcp_execute_and_set(mod_hdcp_write_poll_read_lc_fw,
+			&input->l_prime_read, &status,
+			hdcp, "l_prime_read"))
+		goto out;
+
+out:
+	return status;
+}
+
+static enum mod_hdcp_status locality_check(struct mod_hdcp *hdcp,
+		struct mod_hdcp_event_context *event_ctx,
+		struct mod_hdcp_transition_input_hdcp2 *input)
+{
+	enum mod_hdcp_status status = MOD_HDCP_STATUS_SUCCESS;
+	const bool use_fw = hdcp->config.ddc.funcs.atomic_write_poll_read_i2c
+			&& hdcp->config.ddc.funcs.atomic_write_poll_read_aux
+			&& !hdcp->connection.link.adjust.hdcp2.force_sw_locality_check;
+
+	if (event_ctx->event != MOD_HDCP_EVENT_CALLBACK) {
+		event_ctx->unexpected_event = 1;
+		goto out;
+	}
+
+	if (!mod_hdcp_execute_and_set(mod_hdcp_hdcp2_prepare_lc_init,
+			&input->lc_init_prepare, &status,
+			hdcp, "lc_init_prepare"))
+		goto out;
+
+	status = (use_fw ? locality_check_fw : locality_check_sw)(hdcp, event_ctx, input);
+	if (status != MOD_HDCP_STATUS_SUCCESS)
+		goto out;
+
 	if (!mod_hdcp_execute_and_set(mod_hdcp_hdcp2_validate_l_prime,
 			&input->l_prime_validation, &status,
 			hdcp, "l_prime_validation"))
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) {
diff --git a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c
index 6e064e6ae949..2e6408579194 100644
--- a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c
+++ b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c
@@ -688,3 +688,76 @@ enum mod_hdcp_status mod_hdcp_clear_cp_irq_status(struct mod_hdcp *hdcp)
 
 	return MOD_HDCP_STATUS_INVALID_OPERATION;
 }
+
+static bool write_stall_read_lc_fw_aux(struct mod_hdcp *hdcp)
+{
+	struct mod_hdcp_message_hdcp2 *hdcp2 = &hdcp->auth.msg.hdcp2;
+
+	struct mod_hdcp_atomic_op_aux write = {
+		hdcp_dpcd_addrs[MOD_HDCP_MESSAGE_ID_WRITE_LC_INIT],
+		hdcp2->lc_init + 1,
+		sizeof(hdcp2->lc_init) - 1,
+	};
+	struct mod_hdcp_atomic_op_aux stall = { 0, NULL, 0, };
+	struct mod_hdcp_atomic_op_aux read = {
+		hdcp_dpcd_addrs[MOD_HDCP_MESSAGE_ID_READ_LC_SEND_L_PRIME],
+		hdcp2->lc_l_prime + 1,
+		sizeof(hdcp2->lc_l_prime) - 1,
+	};
+
+	hdcp2->lc_l_prime[0] = HDCP_2_2_LC_SEND_LPRIME;
+
+	return hdcp->config.ddc.funcs.atomic_write_poll_read_aux(
+			hdcp->config.ddc.handle,
+			&write,
+			&stall,
+			&read,
+			16 * 1000,
+			0
+	);
+}
+
+static bool write_poll_read_lc_fw_i2c(struct mod_hdcp *hdcp)
+{
+	struct mod_hdcp_message_hdcp2 *hdcp2 = &hdcp->auth.msg.hdcp2;
+	uint8_t expected_rxstatus[2] = { sizeof(hdcp2->lc_l_prime) };
+
+	hdcp->buf[0] = hdcp_i2c_offsets[MOD_HDCP_MESSAGE_ID_WRITE_LC_INIT];
+	memmove(&hdcp->buf[1], hdcp2->lc_init, sizeof(hdcp2->lc_init));
+
+	struct mod_hdcp_atomic_op_i2c write = {
+		HDCP_I2C_ADDR,
+		0,
+		hdcp->buf,
+		sizeof(hdcp2->lc_init) + 1,
+	};
+	struct mod_hdcp_atomic_op_i2c poll = {
+		HDCP_I2C_ADDR,
+		hdcp_i2c_offsets[MOD_HDCP_MESSAGE_ID_READ_RXSTATUS],
+		expected_rxstatus,
+		sizeof(expected_rxstatus),
+	};
+	struct mod_hdcp_atomic_op_i2c read = {
+		HDCP_I2C_ADDR,
+		hdcp_i2c_offsets[MOD_HDCP_MESSAGE_ID_READ_LC_SEND_L_PRIME],
+		hdcp2->lc_l_prime,
+		sizeof(hdcp2->lc_l_prime),
+	};
+
+	return hdcp->config.ddc.funcs.atomic_write_poll_read_i2c(
+			hdcp->config.ddc.handle,
+			&write,
+			&poll,
+			&read,
+			20 * 1000,
+			6
+	);
+}
+
+enum mod_hdcp_status mod_hdcp_write_poll_read_lc_fw(struct mod_hdcp *hdcp)
+{
+	const bool success = (is_dp_hdcp(hdcp) ? write_stall_read_lc_fw_aux : write_poll_read_lc_fw_i2c)(hdcp);
+
+	return success ? MOD_HDCP_STATUS_SUCCESS : MOD_HDCP_STATUS_DDC_FAILURE;
+}
+
diff --git a/drivers/gpu/drm/amd/display/modules/inc/mod_hdcp.h b/drivers/gpu/drm/amd/display/modules/inc/mod_hdcp.h
index a4d344a4db9e..c42468bb70ac 100644
--- a/drivers/gpu/drm/amd/display/modules/inc/mod_hdcp.h
+++ b/drivers/gpu/drm/amd/display/modules/inc/mod_hdcp.h
@@ -133,9 +133,22 @@ enum mod_hdcp_display_disable_option {
 	MOD_HDCP_DISPLAY_DISABLE_ENCRYPTION,
 };
 
+struct mod_hdcp_atomic_op_i2c {
+	uint8_t address;
+	uint8_t offset;
+	uint8_t *data;
+	uint32_t size;
+};
+
+struct mod_hdcp_atomic_op_aux {
+	uint32_t address;
+	uint8_t *data;
+	uint32_t size;
+};
+
 struct mod_hdcp_ddc {
 	void *handle;
-	struct {
+	struct mod_hdcp_ddc_funcs {
 		bool (*read_i2c)(void *handle,
 				uint32_t address,
 				uint8_t offset,
@@ -153,6 +166,22 @@ struct mod_hdcp_ddc {
 				uint32_t address,
 				const uint8_t *data,
 				uint32_t size);
+		bool (*atomic_write_poll_read_i2c)(
+				void *handle,
+				const struct mod_hdcp_atomic_op_i2c *write,
+				const struct mod_hdcp_atomic_op_i2c *poll,
+				struct mod_hdcp_atomic_op_i2c *read,
+				uint32_t poll_timeout_us,
+				uint8_t poll_mask_msb
+		);
+		bool (*atomic_write_poll_read_aux)(
+				void *handle,
+				const struct mod_hdcp_atomic_op_aux *write,
+				const struct mod_hdcp_atomic_op_aux *poll,
+				struct mod_hdcp_atomic_op_aux *read,
+				uint32_t poll_timeout_us,
+				uint8_t poll_mask_msb
+		);
 	} funcs;
 };
 
@@ -185,7 +214,8 @@ struct mod_hdcp_link_adjustment_hdcp2 {
 	uint8_t force_type		: 2;
 	uint8_t force_no_stored_km	: 1;
 	uint8_t increase_h_prime_timeout: 1;
-	uint8_t reserved		: 3;
+	uint8_t force_sw_locality_check : 1;
+	uint8_t reserved		: 2;
 };
 
 struct mod_hdcp_link_adjustment {
@@ -272,6 +302,10 @@ struct mod_hdcp_display_query {
 struct mod_hdcp_config {
 	struct mod_hdcp_psp psp;
 	struct mod_hdcp_ddc ddc;
+	struct {
+		uint8_t lc_enable_sw_fallback : 1;
+		uint8_t reserved : 7;
+	} debug;
 	uint8_t index;
 };