drm/amd/display: move dp irq handler functions from dc_link_dp to link_dp_irq_handler

Create new files link_dp_irq_handler.c and link_dp_irq_handler.h, and
move DP irq handler functions into them.

Reviewed-by: George Shen <George.Shen@amd.com>
Acked-by: Alan Liu <HaoPing.Liu@amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

11 files changed, 452 insertions, 394 deletions

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 2e7ae4238848..20c719b99e4c 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -1300,7 +1300,7 @@ static void dm_handle_hpd_rx_offload_work(struct work_struct *work)
 		sizeof(test_response));
 	}
 	else if ((dc_link->connector_signal != SIGNAL_TYPE_EDP) &&
-			hpd_rx_irq_check_link_loss_status(dc_link, &offload_work->data) &&
+			dc_link_check_link_loss_status(dc_link, &offload_work->data) &&
 			dc_link_dp_allow_hpd_rx_irq(dc_link)) {
 		dc_link_dp_handle_link_loss(dc_link);
 		spin_lock_irqsave(&offload_work->offload_wq->offload_lock, flags);
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
index d22d34c8d3fd..21cc51923782 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
@@ -53,135 +53,6 @@
 #define DC_TRACE_LEVEL_MESSAGE(...) /* do nothing */
 #include "link/protocols/link_dpcd.h"
 
-static uint8_t get_nibble_at_index(const uint8_t *buf,
-	uint32_t index)
-{
-	uint8_t nibble;
-	nibble = buf[index / 2];
-
-	if (index % 2)
-		nibble >>= 4;
-	else
-		nibble &= 0x0F;
-
-	return nibble;
-}
-
-enum dc_status read_hpd_rx_irq_data(
-	struct dc_link *link,
-	union hpd_irq_data *irq_data)
-{
-	static enum dc_status retval;
-
-	/* The HW reads 16 bytes from 200h on HPD,
-	 * but if we get an AUX_DEFER, the HW cannot retry
-	 * and this causes the CTS tests 4.3.2.1 - 3.2.4 to
-	 * fail, so we now explicitly read 6 bytes which is
-	 * the req from the above mentioned test cases.
-	 *
-	 * For DP 1.4 we need to read those from 2002h range.
-	 */
-	if (link->dpcd_caps.dpcd_rev.raw < DPCD_REV_14)
-		retval = core_link_read_dpcd(
-			link,
-			DP_SINK_COUNT,
-			irq_data->raw,
-			sizeof(union hpd_irq_data));
-	else {
-		/* Read 14 bytes in a single read and then copy only the required fields.
-		 * This is more efficient than doing it in two separate AUX reads. */
-
-		uint8_t tmp[DP_SINK_STATUS_ESI - DP_SINK_COUNT_ESI + 1];
-
-		retval = core_link_read_dpcd(
-			link,
-			DP_SINK_COUNT_ESI,
-			tmp,
-			sizeof(tmp));
-
-		if (retval != DC_OK)
-			return retval;
-
-		irq_data->bytes.sink_cnt.raw = tmp[DP_SINK_COUNT_ESI - DP_SINK_COUNT_ESI];
-		irq_data->bytes.device_service_irq.raw = tmp[DP_DEVICE_SERVICE_IRQ_VECTOR_ESI0 - DP_SINK_COUNT_ESI];
-		irq_data->bytes.lane01_status.raw = tmp[DP_LANE0_1_STATUS_ESI - DP_SINK_COUNT_ESI];
-		irq_data->bytes.lane23_status.raw = tmp[DP_LANE2_3_STATUS_ESI - DP_SINK_COUNT_ESI];
-		irq_data->bytes.lane_status_updated.raw = tmp[DP_LANE_ALIGN_STATUS_UPDATED_ESI - DP_SINK_COUNT_ESI];
-		irq_data->bytes.sink_status.raw = tmp[DP_SINK_STATUS_ESI - DP_SINK_COUNT_ESI];
-	}
-
-	return retval;
-}
-
-bool hpd_rx_irq_check_link_loss_status(
-	struct dc_link *link,
-	union hpd_irq_data *hpd_irq_dpcd_data)
-{
-	uint8_t irq_reg_rx_power_state = 0;
-	enum dc_status dpcd_result = DC_ERROR_UNEXPECTED;
-	union lane_status lane_status;
-	uint32_t lane;
-	bool sink_status_changed;
-	bool return_code;
-
-	sink_status_changed = false;
-	return_code = false;
-
-	if (link->cur_link_settings.lane_count == 0)
-		return return_code;
-
-	/*1. Check that Link Status changed, before re-training.*/
-
-	/*parse lane status*/
-	for (lane = 0; lane < link->cur_link_settings.lane_count; lane++) {
-		/* check status of lanes 0,1
-		 * changed DpcdAddress_Lane01Status (0x202)
-		 */
-		lane_status.raw = get_nibble_at_index(
-			&hpd_irq_dpcd_data->bytes.lane01_status.raw,
-			lane);
-
-		if (!lane_status.bits.CHANNEL_EQ_DONE_0 ||
-			!lane_status.bits.CR_DONE_0 ||
-			!lane_status.bits.SYMBOL_LOCKED_0) {
-			/* if one of the channel equalization, clock
-			 * recovery or symbol lock is dropped
-			 * consider it as (link has been
-			 * dropped) dp sink status has changed
-			 */
-			sink_status_changed = true;
-			break;
-		}
-	}
-
-	/* Check interlane align.*/
-	if (sink_status_changed ||
-		!hpd_irq_dpcd_data->bytes.lane_status_updated.bits.INTERLANE_ALIGN_DONE) {
-
-		DC_LOG_HW_HPD_IRQ("%s: Link Status changed.\n", __func__);
-
-		return_code = true;
-
-		/*2. Check that we can handle interrupt: Not in FS DOS,
-		 *  Not in "Display Timeout" state, Link is trained.
-		 */
-		dpcd_result = core_link_read_dpcd(link,
-			DP_SET_POWER,
-			&irq_reg_rx_power_state,
-			sizeof(irq_reg_rx_power_state));
-
-		if (dpcd_result != DC_OK) {
-			DC_LOG_HW_HPD_IRQ("%s: DPCD read failed to obtain power state.\n",
-				__func__);
-		} else {
-			if (irq_reg_rx_power_state != DP_SET_POWER_D0)
-				return_code = false;
-		}
-	}
-
-	return return_code;
-}
-
 bool dp_validate_mode_timing(
 	struct dc_link *link,
 	const struct dc_crtc_timing *timing)
@@ -233,88 +104,6 @@ bool dp_validate_mode_timing(
 		return false;
 }
 
-/*************************Short Pulse IRQ***************************/
-bool dc_link_dp_allow_hpd_rx_irq(const struct dc_link *link)
-{
-	/*
-	 * Don't handle RX IRQ unless one of following is met:
-	 * 1) The link is established (cur_link_settings != unknown)
-	 * 2) We know we're dealing with a branch device, SST or MST
-	 */
-
-	if ((link->cur_link_settings.lane_count != LANE_COUNT_UNKNOWN) ||
-		is_dp_branch_device(link))
-		return true;
-
-	return false;
-}
-
-static bool handle_hpd_irq_psr_sink(struct dc_link *link)
-{
-	union dpcd_psr_configuration psr_configuration;
-
-	if (!link->psr_settings.psr_feature_enabled)
-		return false;
-
-	dm_helpers_dp_read_dpcd(
-		link->ctx,
-		link,
-		368,/*DpcdAddress_PSR_Enable_Cfg*/
-		&psr_configuration.raw,
-		sizeof(psr_configuration.raw));
-
-	if (psr_configuration.bits.ENABLE) {
-		unsigned char dpcdbuf[3] = {0};
-		union psr_error_status psr_error_status;
-		union psr_sink_psr_status psr_sink_psr_status;
-
-		dm_helpers_dp_read_dpcd(
-			link->ctx,
-			link,
-			0x2006, /*DpcdAddress_PSR_Error_Status*/
-			(unsigned char *) dpcdbuf,
-			sizeof(dpcdbuf));
-
-		/*DPCD 2006h   ERROR STATUS*/
-		psr_error_status.raw = dpcdbuf[0];
-		/*DPCD 2008h   SINK PANEL SELF REFRESH STATUS*/
-		psr_sink_psr_status.raw = dpcdbuf[2];
-
-		if (psr_error_status.bits.LINK_CRC_ERROR ||
-				psr_error_status.bits.RFB_STORAGE_ERROR ||
-				psr_error_status.bits.VSC_SDP_ERROR) {
-			bool allow_active;
-
-			/* Acknowledge and clear error bits */
-			dm_helpers_dp_write_dpcd(
-				link->ctx,
-				link,
-				8198,/*DpcdAddress_PSR_Error_Status*/
-				&psr_error_status.raw,
-				sizeof(psr_error_status.raw));
-
-			/* PSR error, disable and re-enable PSR */
-			if (link->psr_settings.psr_allow_active) {
-				allow_active = false;
-				dc_link_set_psr_allow_active(link, &allow_active, true, false, NULL);
-				allow_active = true;
-				dc_link_set_psr_allow_active(link, &allow_active, true, false, NULL);
-			}
-
-			return true;
-		} else if (psr_sink_psr_status.bits.SINK_SELF_REFRESH_STATUS ==
-				PSR_SINK_STATE_ACTIVE_DISPLAY_FROM_SINK_RFB){
-			/* No error is detect, PSR is active.
-			 * We should return with IRQ_HPD handled without
-			 * checking for loss of sync since PSR would have
-			 * powered down main link.
-			 */
-			return true;
-		}
-	}
-	return false;
-}
-
 static enum dc_link_rate get_link_rate_from_test_link_rate(uint8_t test_rate)
 {
 	switch (test_rate) {
@@ -533,7 +322,7 @@ static void dp_test_send_phy_test_pattern(struct dc_link *link)
 		(unsigned int)(link->cur_link_settings.lane_count);
 		lane++) {
 		dpcd_lane_adjust.raw =
-			get_nibble_at_index(&dpcd_lane_adjustment[0].raw, lane);
+			dp_get_nibble_at_index(&dpcd_lane_adjustment[0].raw, lane);
 		if (link_dp_get_encoding_format(&link->cur_link_settings) ==
 				DP_8b_10b_ENCODING) {
 			link_training_settings.hw_lane_settings[lane].VOLTAGE_SWING =
@@ -725,171 +514,6 @@ void dc_link_dp_handle_automated_test(struct dc_link *link)
 			sizeof(test_response));
 }
 
-void dc_link_dp_handle_link_loss(struct dc_link *link)
-{
-	int i;
-	struct pipe_ctx *pipe_ctx;
-
-	for (i = 0; i < MAX_PIPES; i++) {
-		pipe_ctx = &link->dc->current_state->res_ctx.pipe_ctx[i];
-		if (pipe_ctx && pipe_ctx->stream && pipe_ctx->stream->link == link)
-			break;
-	}
-
-	if (pipe_ctx == NULL || pipe_ctx->stream == NULL)
-		return;
-
-	for (i = 0; i < MAX_PIPES; i++) {
-		pipe_ctx = &link->dc->current_state->res_ctx.pipe_ctx[i];
-		if (pipe_ctx && pipe_ctx->stream && !pipe_ctx->stream->dpms_off &&
-				pipe_ctx->stream->link == link && !pipe_ctx->prev_odm_pipe)
-			core_link_disable_stream(pipe_ctx);
-	}
-
-	for (i = 0; i < MAX_PIPES; i++) {
-		pipe_ctx = &link->dc->current_state->res_ctx.pipe_ctx[i];
-		if (pipe_ctx && pipe_ctx->stream && !pipe_ctx->stream->dpms_off
-				&& pipe_ctx->stream->link == link && !pipe_ctx->prev_odm_pipe) {
-			// Always use max settings here for DP 1.4a LL Compliance CTS
-			if (link->is_automated) {
-				pipe_ctx->link_config.dp_link_settings.lane_count =
-						link->verified_link_cap.lane_count;
-				pipe_ctx->link_config.dp_link_settings.link_rate =
-						link->verified_link_cap.link_rate;
-				pipe_ctx->link_config.dp_link_settings.link_spread =
-						link->verified_link_cap.link_spread;
-			}
-			core_link_enable_stream(link->dc->current_state, pipe_ctx);
-		}
-	}
-}
-
-bool dc_link_handle_hpd_rx_irq(struct dc_link *link, union hpd_irq_data *out_hpd_irq_dpcd_data, bool *out_link_loss,
-							bool defer_handling, bool *has_left_work)
-{
-	union hpd_irq_data hpd_irq_dpcd_data = {0};
-	union device_service_irq device_service_clear = {0};
-	enum dc_status result;
-	bool status = false;
-
-	if (out_link_loss)
-		*out_link_loss = false;
-
-	if (has_left_work)
-		*has_left_work = false;
-	/* For use cases related to down stream connection status change,
-	 * PSR and device auto test, refer to function handle_sst_hpd_irq
-	 * in DAL2.1*/
-
-	DC_LOG_HW_HPD_IRQ("%s: Got short pulse HPD on link %d\n",
-		__func__, link->link_index);
-
-
-	 /* All the "handle_hpd_irq_xxx()" methods
-		 * should be called only after
-		 * dal_dpsst_ls_read_hpd_irq_data
-		 * Order of calls is important too
-		 */
-	result = read_hpd_rx_irq_data(link, &hpd_irq_dpcd_data);
-	if (out_hpd_irq_dpcd_data)
-		*out_hpd_irq_dpcd_data = hpd_irq_dpcd_data;
-
-	if (result != DC_OK) {
-		DC_LOG_HW_HPD_IRQ("%s: DPCD read failed to obtain irq data\n",
-			__func__);
-		return false;
-	}
-
-	if (hpd_irq_dpcd_data.bytes.device_service_irq.bits.AUTOMATED_TEST) {
-		// Workaround for DP 1.4a LL Compliance CTS as USB4 has to share encoders unlike DP and USBC
-		link->is_automated = true;
-		device_service_clear.bits.AUTOMATED_TEST = 1;
-		core_link_write_dpcd(
-			link,
-			DP_DEVICE_SERVICE_IRQ_VECTOR,
-			&device_service_clear.raw,
-			sizeof(device_service_clear.raw));
-		device_service_clear.raw = 0;
-		if (defer_handling && has_left_work)
-			*has_left_work = true;
-		else
-			dc_link_dp_handle_automated_test(link);
-		return false;
-	}
-
-	if (!dc_link_dp_allow_hpd_rx_irq(link)) {
-		DC_LOG_HW_HPD_IRQ("%s: skipping HPD handling on %d\n",
-			__func__, link->link_index);
-		return false;
-	}
-
-	if (handle_hpd_irq_psr_sink(link))
-		/* PSR-related error was detected and handled */
-		return true;
-
-	/* If PSR-related error handled, Main link may be off,
-	 * so do not handle as a normal sink status change interrupt.
-	 */
-
-	if (hpd_irq_dpcd_data.bytes.device_service_irq.bits.UP_REQ_MSG_RDY) {
-		if (defer_handling && has_left_work)
-			*has_left_work = true;
-		return true;
-	}
-
-	/* check if we have MST msg and return since we poll for it */
-	if (hpd_irq_dpcd_data.bytes.device_service_irq.bits.DOWN_REP_MSG_RDY) {
-		if (defer_handling && has_left_work)
-			*has_left_work = true;
-		return false;
-	}
-
-	/* For now we only handle 'Downstream port status' case.
-	 * If we got sink count changed it means
-	 * Downstream port status changed,
-	 * then DM should call DC to do the detection.
-	 * NOTE: Do not handle link loss on eDP since it is internal link*/
-	if ((link->connector_signal != SIGNAL_TYPE_EDP) &&
-		hpd_rx_irq_check_link_loss_status(
-			link,
-			&hpd_irq_dpcd_data)) {
-		/* Connectivity log: link loss */
-		CONN_DATA_LINK_LOSS(link,
-					hpd_irq_dpcd_data.raw,
-					sizeof(hpd_irq_dpcd_data),
-					"Status: ");
-
-		if (defer_handling && has_left_work)
-			*has_left_work = true;
-		else
-			dc_link_dp_handle_link_loss(link);
-
-		status = false;
-		if (out_link_loss)
-			*out_link_loss = true;
-
-		dp_trace_link_loss_increment(link);
-	}
-
-	if (link->type == dc_connection_sst_branch &&
-		hpd_irq_dpcd_data.bytes.sink_cnt.bits.SINK_COUNT
-			!= link->dpcd_sink_count)
-		status = true;
-
-	/* reasons for HPD RX:
-	 * 1. Link Loss - ie Re-train the Link
-	 * 2. MST sideband message
-	 * 3. Automated Test - ie. Internal Commit
-	 * 4. CP (copy protection) - (not interesting for DM???)
-	 * 5. DRR
-	 * 6. Downstream Port status changed
-	 * -ie. Detect - this the only one
-	 * which is interesting for DM because
-	 * it must call dc_link_detect.
-	 */
-	return status;
-}
-
 static bool is_dp_phy_pattern(enum dp_test_pattern test_pattern)
 {
 	if ((DP_TEST_PATTERN_PHY_PATTERN_BEGIN <= test_pattern &&
@@ -1469,7 +1093,7 @@ static void get_lane_status(
 			sizeof(dpcd_buf));
 
 	for (lane = 0; lane < lane_count; lane++) {
-		status[lane].raw = get_nibble_at_index(&dpcd_buf[0], lane);
+		status[lane].raw = dp_get_nibble_at_index(&dpcd_buf[0], lane);
 	}
 
 	status_updated->raw = dpcd_buf[2];
diff --git a/drivers/gpu/drm/amd/display/dc/dc_link.h b/drivers/gpu/drm/amd/display/dc/dc_link.h
index 19d15b75661e..de0a1dbe4272 100644
--- a/drivers/gpu/drm/amd/display/dc/dc_link.h
+++ b/drivers/gpu/drm/amd/display/dc/dc_link.h
@@ -431,7 +431,8 @@ bool dc_link_wait_for_t12(struct dc_link *link);
 void dc_link_dp_handle_automated_test(struct dc_link *link);
 void dc_link_dp_handle_link_loss(struct dc_link *link);
 bool dc_link_dp_allow_hpd_rx_irq(const struct dc_link *link);
-
+bool dc_link_check_link_loss_status(struct dc_link *link,
+				       union hpd_irq_data *hpd_irq_dpcd_data);
 struct dc_sink_init_data;
 
 struct dc_sink *dc_link_add_remote_sink(
diff --git a/drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h b/drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h
index b7bd272f3118..10bef15d980e 100644
--- a/drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h
+++ b/drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h
@@ -51,12 +51,6 @@ bool dp_validate_mode_timing(
 	struct dc_link *link,
 	const struct dc_crtc_timing *timing);
 
-bool hpd_rx_irq_check_link_loss_status(struct dc_link *link,
-				       union hpd_irq_data *hpd_irq_dpcd_data);
-enum dc_status read_hpd_rx_irq_data(
-	struct dc_link *link,
-	union hpd_irq_data *irq_data);
-
 void dp_enable_mst_on_sink(struct dc_link *link, bool enable);
 
 enum dc_status dp_set_fec_ready(struct dc_link *link, const struct link_resource *link_res, bool ready);
diff --git a/drivers/gpu/drm/amd/display/dc/link/Makefile b/drivers/gpu/drm/amd/display/dc/link/Makefile
index 4198f66585f8..3ecb72be4dac 100644
--- a/drivers/gpu/drm/amd/display/dc/link/Makefile
+++ b/drivers/gpu/drm/amd/display/dc/link/Makefile
@@ -48,7 +48,7 @@ LINK_PROTOCOLS = link_hpd.o link_ddc.o link_dpcd.o link_dp_dpia.o \
 link_dp_training.o link_dp_training_8b_10b.o link_dp_training_128b_132b.o \
 link_dp_training_dpia.o link_dp_training_auxless.o \
 link_dp_training_fixed_vs_pe_retimer.o link_dp_phy.o link_dp_capability.o \
-link_edp_panel_control.o
+link_edp_panel_control.o link_dp_irq_handler.o
 
 AMD_DAL_LINK_PROTOCOLS = $(addprefix $(AMDDALPATH)/dc/link/protocols/, \
 $(LINK_PROTOCOLS))
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c
index ba53437f9631..8a6fabe7e0e5 100644
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c
@@ -40,6 +40,7 @@
 #include "link_dp_dpia.h"
 #include "link_dp_phy.h"
 #include "link_edp_panel_control.h"
+#include "link_dp_irq_handler.h"
 #include "link/accessories/link_dp_trace.h"
 #include "link_dp_training.h"
 #include "atomfirmware.h"
@@ -2127,8 +2128,8 @@ static bool dp_verify_link_cap(
 		if (status == LINK_TRAINING_SUCCESS) {
 			success = true;
 			udelay(1000);
-			if (read_hpd_rx_irq_data(link, &irq_data) == DC_OK &&
-					hpd_rx_irq_check_link_loss_status(
+			if (dp_read_hpd_rx_irq_data(link, &irq_data) == DC_OK &&
+					dc_link_check_link_loss_status(
 							link,
 							&irq_data))
 				(*fail_count)++;
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia.c
index 6136db392548..9a42fe5958e9 100644
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia.c
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia.c
@@ -104,4 +104,3 @@ bool dc_link_dpia_query_hpd_status(struct dc_link *link)
 
 	return is_hpd_high;
 }
-
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_irq_handler.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_irq_handler.c
new file mode 100644
index 000000000000..9a832a9ea42d
--- /dev/null
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_irq_handler.c
@@ -0,0 +1,401 @@
+/*
+ * Copyright 2022 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: AMD
+ *
+ */
+
+/* FILE POLICY AND INTENDED USAGE:
+ *
+ *
+ */
+
+#include "link_dp_irq_handler.h"
+#include "link_dpcd.h"
+#include "link_dp_training.h"
+#include "link_dp_capability.h"
+#include "link/accessories/link_dp_trace.h"
+#include "dm_helpers.h"
+
+#define DC_LOGGER_INIT(logger)
+
+bool dc_link_check_link_loss_status(
+	struct dc_link *link,
+	union hpd_irq_data *hpd_irq_dpcd_data)
+{
+	uint8_t irq_reg_rx_power_state = 0;
+	enum dc_status dpcd_result = DC_ERROR_UNEXPECTED;
+	union lane_status lane_status;
+	uint32_t lane;
+	bool sink_status_changed;
+	bool return_code;
+
+	sink_status_changed = false;
+	return_code = false;
+
+	if (link->cur_link_settings.lane_count == 0)
+		return return_code;
+
+	/*1. Check that Link Status changed, before re-training.*/
+
+	/*parse lane status*/
+	for (lane = 0; lane < link->cur_link_settings.lane_count; lane++) {
+		/* check status of lanes 0,1
+		 * changed DpcdAddress_Lane01Status (0x202)
+		 */
+		lane_status.raw = dp_get_nibble_at_index(
+			&hpd_irq_dpcd_data->bytes.lane01_status.raw,
+			lane);
+
+		if (!lane_status.bits.CHANNEL_EQ_DONE_0 ||
+			!lane_status.bits.CR_DONE_0 ||
+			!lane_status.bits.SYMBOL_LOCKED_0) {
+			/* if one of the channel equalization, clock
+			 * recovery or symbol lock is dropped
+			 * consider it as (link has been
+			 * dropped) dp sink status has changed
+			 */
+			sink_status_changed = true;
+			break;
+		}
+	}
+
+	/* Check interlane align.*/
+	if (sink_status_changed ||
+		!hpd_irq_dpcd_data->bytes.lane_status_updated.bits.INTERLANE_ALIGN_DONE) {
+
+		DC_LOG_HW_HPD_IRQ("%s: Link Status changed.\n", __func__);
+
+		return_code = true;
+
+		/*2. Check that we can handle interrupt: Not in FS DOS,
+		 *  Not in "Display Timeout" state, Link is trained.
+		 */
+		dpcd_result = core_link_read_dpcd(link,
+			DP_SET_POWER,
+			&irq_reg_rx_power_state,
+			sizeof(irq_reg_rx_power_state));
+
+		if (dpcd_result != DC_OK) {
+			DC_LOG_HW_HPD_IRQ("%s: DPCD read failed to obtain power state.\n",
+				__func__);
+		} else {
+			if (irq_reg_rx_power_state != DP_SET_POWER_D0)
+				return_code = false;
+		}
+	}
+
+	return return_code;
+}
+
+static bool handle_hpd_irq_psr_sink(struct dc_link *link)
+{
+	union dpcd_psr_configuration psr_configuration;
+
+	if (!link->psr_settings.psr_feature_enabled)
+		return false;
+
+	dm_helpers_dp_read_dpcd(
+		link->ctx,
+		link,
+		368,/*DpcdAddress_PSR_Enable_Cfg*/
+		&psr_configuration.raw,
+		sizeof(psr_configuration.raw));
+
+	if (psr_configuration.bits.ENABLE) {
+		unsigned char dpcdbuf[3] = {0};
+		union psr_error_status psr_error_status;
+		union psr_sink_psr_status psr_sink_psr_status;
+
+		dm_helpers_dp_read_dpcd(
+			link->ctx,
+			link,
+			0x2006, /*DpcdAddress_PSR_Error_Status*/
+			(unsigned char *) dpcdbuf,
+			sizeof(dpcdbuf));
+
+		/*DPCD 2006h   ERROR STATUS*/
+		psr_error_status.raw = dpcdbuf[0];
+		/*DPCD 2008h   SINK PANEL SELF REFRESH STATUS*/
+		psr_sink_psr_status.raw = dpcdbuf[2];
+
+		if (psr_error_status.bits.LINK_CRC_ERROR ||
+				psr_error_status.bits.RFB_STORAGE_ERROR ||
+				psr_error_status.bits.VSC_SDP_ERROR) {
+			bool allow_active;
+
+			/* Acknowledge and clear error bits */
+			dm_helpers_dp_write_dpcd(
+				link->ctx,
+				link,
+				8198,/*DpcdAddress_PSR_Error_Status*/
+				&psr_error_status.raw,
+				sizeof(psr_error_status.raw));
+
+			/* PSR error, disable and re-enable PSR */
+			if (link->psr_settings.psr_allow_active) {
+				allow_active = false;
+				dc_link_set_psr_allow_active(link, &allow_active, true, false, NULL);
+				allow_active = true;
+				dc_link_set_psr_allow_active(link, &allow_active, true, false, NULL);
+			}
+
+			return true;
+		} else if (psr_sink_psr_status.bits.SINK_SELF_REFRESH_STATUS ==
+				PSR_SINK_STATE_ACTIVE_DISPLAY_FROM_SINK_RFB){
+			/* No error is detect, PSR is active.
+			 * We should return with IRQ_HPD handled without
+			 * checking for loss of sync since PSR would have
+			 * powered down main link.
+			 */
+			return true;
+		}
+	}
+	return false;
+}
+
+void dc_link_dp_handle_link_loss(struct dc_link *link)
+{
+	int i;
+	struct pipe_ctx *pipe_ctx;
+
+	for (i = 0; i < MAX_PIPES; i++) {
+		pipe_ctx = &link->dc->current_state->res_ctx.pipe_ctx[i];
+		if (pipe_ctx && pipe_ctx->stream && pipe_ctx->stream->link == link)
+			break;
+	}
+
+	if (pipe_ctx == NULL || pipe_ctx->stream == NULL)
+		return;
+
+	for (i = 0; i < MAX_PIPES; i++) {
+		pipe_ctx = &link->dc->current_state->res_ctx.pipe_ctx[i];
+		if (pipe_ctx && pipe_ctx->stream && !pipe_ctx->stream->dpms_off &&
+				pipe_ctx->stream->link == link && !pipe_ctx->prev_odm_pipe)
+			core_link_disable_stream(pipe_ctx);
+	}
+
+	for (i = 0; i < MAX_PIPES; i++) {
+		pipe_ctx = &link->dc->current_state->res_ctx.pipe_ctx[i];
+		if (pipe_ctx && pipe_ctx->stream && !pipe_ctx->stream->dpms_off
+				&& pipe_ctx->stream->link == link && !pipe_ctx->prev_odm_pipe) {
+			// Always use max settings here for DP 1.4a LL Compliance CTS
+			if (link->is_automated) {
+				pipe_ctx->link_config.dp_link_settings.lane_count =
+						link->verified_link_cap.lane_count;
+				pipe_ctx->link_config.dp_link_settings.link_rate =
+						link->verified_link_cap.link_rate;
+				pipe_ctx->link_config.dp_link_settings.link_spread =
+						link->verified_link_cap.link_spread;
+			}
+			core_link_enable_stream(link->dc->current_state, pipe_ctx);
+		}
+	}
+}
+
+enum dc_status dp_read_hpd_rx_irq_data(
+	struct dc_link *link,
+	union hpd_irq_data *irq_data)
+{
+	static enum dc_status retval;
+
+	/* The HW reads 16 bytes from 200h on HPD,
+	 * but if we get an AUX_DEFER, the HW cannot retry
+	 * and this causes the CTS tests 4.3.2.1 - 3.2.4 to
+	 * fail, so we now explicitly read 6 bytes which is
+	 * the req from the above mentioned test cases.
+	 *
+	 * For DP 1.4 we need to read those from 2002h range.
+	 */
+	if (link->dpcd_caps.dpcd_rev.raw < DPCD_REV_14)
+		retval = core_link_read_dpcd(
+			link,
+			DP_SINK_COUNT,
+			irq_data->raw,
+			sizeof(union hpd_irq_data));
+	else {
+		/* Read 14 bytes in a single read and then copy only the required fields.
+		 * This is more efficient than doing it in two separate AUX reads. */
+
+		uint8_t tmp[DP_SINK_STATUS_ESI - DP_SINK_COUNT_ESI + 1];
+
+		retval = core_link_read_dpcd(
+			link,
+			DP_SINK_COUNT_ESI,
+			tmp,
+			sizeof(tmp));
+
+		if (retval != DC_OK)
+			return retval;
+
+		irq_data->bytes.sink_cnt.raw = tmp[DP_SINK_COUNT_ESI - DP_SINK_COUNT_ESI];
+		irq_data->bytes.device_service_irq.raw = tmp[DP_DEVICE_SERVICE_IRQ_VECTOR_ESI0 - DP_SINK_COUNT_ESI];
+		irq_data->bytes.lane01_status.raw = tmp[DP_LANE0_1_STATUS_ESI - DP_SINK_COUNT_ESI];
+		irq_data->bytes.lane23_status.raw = tmp[DP_LANE2_3_STATUS_ESI - DP_SINK_COUNT_ESI];
+		irq_data->bytes.lane_status_updated.raw = tmp[DP_LANE_ALIGN_STATUS_UPDATED_ESI - DP_SINK_COUNT_ESI];
+		irq_data->bytes.sink_status.raw = tmp[DP_SINK_STATUS_ESI - DP_SINK_COUNT_ESI];
+	}
+
+	return retval;
+}
+
+/*************************Short Pulse IRQ***************************/
+bool dc_link_dp_allow_hpd_rx_irq(const struct dc_link *link)
+{
+	/*
+	 * Don't handle RX IRQ unless one of following is met:
+	 * 1) The link is established (cur_link_settings != unknown)
+	 * 2) We know we're dealing with a branch device, SST or MST
+	 */
+
+	if ((link->cur_link_settings.lane_count != LANE_COUNT_UNKNOWN) ||
+		is_dp_branch_device(link))
+		return true;
+
+	return false;
+}
+
+bool dc_link_handle_hpd_rx_irq(struct dc_link *link, union hpd_irq_data *out_hpd_irq_dpcd_data, bool *out_link_loss,
+							bool defer_handling, bool *has_left_work)
+{
+	union hpd_irq_data hpd_irq_dpcd_data = {0};
+	union device_service_irq device_service_clear = {0};
+	enum dc_status result;
+	bool status = false;
+
+	if (out_link_loss)
+		*out_link_loss = false;
+
+	if (has_left_work)
+		*has_left_work = false;
+	/* For use cases related to down stream connection status change,
+	 * PSR and device auto test, refer to function handle_sst_hpd_irq
+	 * in DAL2.1*/
+
+	DC_LOG_HW_HPD_IRQ("%s: Got short pulse HPD on link %d\n",
+		__func__, link->link_index);
+
+
+	 /* All the "handle_hpd_irq_xxx()" methods
+		 * should be called only after
+		 * dal_dpsst_ls_read_hpd_irq_data
+		 * Order of calls is important too
+		 */
+	result = dp_read_hpd_rx_irq_data(link, &hpd_irq_dpcd_data);
+	if (out_hpd_irq_dpcd_data)
+		*out_hpd_irq_dpcd_data = hpd_irq_dpcd_data;
+
+	if (result != DC_OK) {
+		DC_LOG_HW_HPD_IRQ("%s: DPCD read failed to obtain irq data\n",
+			__func__);
+		return false;
+	}
+
+	if (hpd_irq_dpcd_data.bytes.device_service_irq.bits.AUTOMATED_TEST) {
+		// Workaround for DP 1.4a LL Compliance CTS as USB4 has to share encoders unlike DP and USBC
+		link->is_automated = true;
+		device_service_clear.bits.AUTOMATED_TEST = 1;
+		core_link_write_dpcd(
+			link,
+			DP_DEVICE_SERVICE_IRQ_VECTOR,
+			&device_service_clear.raw,
+			sizeof(device_service_clear.raw));
+		device_service_clear.raw = 0;
+		if (defer_handling && has_left_work)
+			*has_left_work = true;
+		else
+			dc_link_dp_handle_automated_test(link);
+		return false;
+	}
+
+	if (!dc_link_dp_allow_hpd_rx_irq(link)) {
+		DC_LOG_HW_HPD_IRQ("%s: skipping HPD handling on %d\n",
+			__func__, link->link_index);
+		return false;
+	}
+
+	if (handle_hpd_irq_psr_sink(link))
+		/* PSR-related error was detected and handled */
+		return true;
+
+	/* If PSR-related error handled, Main link may be off,
+	 * so do not handle as a normal sink status change interrupt.
+	 */
+
+	if (hpd_irq_dpcd_data.bytes.device_service_irq.bits.UP_REQ_MSG_RDY) {
+		if (defer_handling && has_left_work)
+			*has_left_work = true;
+		return true;
+	}
+
+	/* check if we have MST msg and return since we poll for it */
+	if (hpd_irq_dpcd_data.bytes.device_service_irq.bits.DOWN_REP_MSG_RDY) {
+		if (defer_handling && has_left_work)
+			*has_left_work = true;
+		return false;
+	}
+
+	/* For now we only handle 'Downstream port status' case.
+	 * If we got sink count changed it means
+	 * Downstream port status changed,
+	 * then DM should call DC to do the detection.
+	 * NOTE: Do not handle link loss on eDP since it is internal link*/
+	if ((link->connector_signal != SIGNAL_TYPE_EDP) &&
+		dc_link_check_link_loss_status(
+			link,
+			&hpd_irq_dpcd_data)) {
+		/* Connectivity log: link loss */
+		CONN_DATA_LINK_LOSS(link,
+					hpd_irq_dpcd_data.raw,
+					sizeof(hpd_irq_dpcd_data),
+					"Status: ");
+
+		if (defer_handling && has_left_work)
+			*has_left_work = true;
+		else
+			dc_link_dp_handle_link_loss(link);
+
+		status = false;
+		if (out_link_loss)
+			*out_link_loss = true;
+
+		dp_trace_link_loss_increment(link);
+	}
+
+	if (link->type == dc_connection_sst_branch &&
+		hpd_irq_dpcd_data.bytes.sink_cnt.bits.SINK_COUNT
+			!= link->dpcd_sink_count)
+		status = true;
+
+	/* reasons for HPD RX:
+	 * 1. Link Loss - ie Re-train the Link
+	 * 2. MST sideband message
+	 * 3. Automated Test - ie. Internal Commit
+	 * 4. CP (copy protection) - (not interesting for DM???)
+	 * 5. DRR
+	 * 6. Downstream Port status changed
+	 * -ie. Detect - this the only one
+	 * which is interesting for DM because
+	 * it must call dc_link_detect.
+	 */
+	return status;
+}
+
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_irq_handler.h b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_irq_handler.h
new file mode 100644
index 000000000000..cac7acd33511
--- /dev/null
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_irq_handler.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright 2022 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: AMD
+ *
+ */
+
+#ifndef __DC_LINK_DP_IRQ_HANDLER_H__
+#define __DC_LINK_DP_IRQ_HANDLER_H__
+
+#include "link.h"
+
+enum dc_status dp_read_hpd_rx_irq_data(
+	struct dc_link *link,
+	union hpd_irq_data *irq_data);
+
+#endif /* __DC_LINK_DP_IRQ_HANDLER_H__ */
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c
index fefefd72d80a..2a5f61f4d744 100644
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.c
@@ -240,7 +240,7 @@ enum dpcd_training_patterns
 	return dpcd_tr_pattern;
 }
 
-static uint8_t get_nibble_at_index(const uint8_t *buf,
+uint8_t dp_get_nibble_at_index(const uint8_t *buf,
 	uint32_t index)
 {
 	uint8_t nibble;
@@ -520,7 +520,7 @@ enum link_training_result dp_check_link_loss_status(
 		/*
 		 * check lanes status
 		 */
-		lane_status.raw = get_nibble_at_index(&dpcd_buf[2], lane);
+		lane_status.raw = dp_get_nibble_at_index(&dpcd_buf[2], lane);
 
 		if (!lane_status.bits.CHANNEL_EQ_DONE_0 ||
 			!lane_status.bits.CR_DONE_0 ||
@@ -579,9 +579,9 @@ enum dc_status dp_get_lane_status_and_lane_adjust(
 		lane++) {
 
 		ln_status[lane].raw =
-			get_nibble_at_index(&dpcd_buf[0], lane);
+			dp_get_nibble_at_index(&dpcd_buf[0], lane);
 		ln_adjust[lane].raw =
-			get_nibble_at_index(&dpcd_buf[lane_adjust_offset], lane);
+			dp_get_nibble_at_index(&dpcd_buf[lane_adjust_offset], lane);
 	}
 
 	ln_align->raw = dpcd_buf[2];
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.h b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.h
index 376d370e3bbb..a04948635369 100644
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.h
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training.h
@@ -176,4 +176,7 @@ void dp_log_training_result(
 
 uint32_t dp_translate_training_aux_read_interval(
 		uint32_t dpcd_aux_read_interval);
+
+uint8_t dp_get_nibble_at_index(const uint8_t *buf,
+	uint32_t index);
 #endif /* __DC_LINK_DP_TRAINING_H__ */