video-driver: prepare conflict free dependency list

Convert multi-parent, multi-child based dependency tree
into flattened list. It is organized in such a way that
all parents willbe present before self or any child node.

For some caps, adjust sequence is called without preparing
parent nodes. So that is leading to undefined behaviour.

Added change to address these problems.

Change-Id: Ib28cae8a4ed7e019c80ecfc06519ef78ffa4dc08
Signed-off-by: Govindaraj Rajagopal <[email protected]>

driver/vidc/inc/msm_vidc_control.h

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
- * Copyright (c) 2020-2021,, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2020-2022,, The Linux Foundation. All rights reserved.
  */
 
 #ifndef _MSM_VIDC_CONTROL_H_
@@ -44,6 +44,7 @@ int msm_vidc_adjust_bitrate_boost(void *instance, struct v4l2_ctrl *ctrl);
 int msm_vidc_adjust_min_quality(void *instance, struct v4l2_ctrl *ctrl);
 int msm_vidc_adjust_lowlatency_mode(void *instance, struct v4l2_ctrl *ctrl);
 int msm_vidc_adjust_v4l2_properties(struct msm_vidc_inst *inst);
+int msm_vidc_prepare_dependency_list(struct msm_vidc_inst *inst);
 int msm_vidc_adjust_session_priority(void *instance, struct v4l2_ctrl *ctrl);
 int msm_vidc_adjust_roi_info(void *instance, struct v4l2_ctrl *ctrl);
 int msm_vidc_adjust_all_intra(void *instance, struct v4l2_ctrl *ctrl);

driver/vidc/inc/msm_vidc_inst.h

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
- * Copyright (c) 2020-2021,, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2020-2022,, The Linux Foundation. All rights reserved.
  */
 
 #ifndef _MSM_VIDC_INST_H_
@@ -143,6 +143,7 @@ struct msm_vidc_inst {
 	struct list_head                   response_works; /* list of struct response_work */
 	struct list_head                   enc_input_crs;
 	struct list_head                   dmabuf_tracker; /* list of struct msm_memory_dmabuf */
+	struct list_head                   caps_list; /* list of struct msm_vidc_inst_cap_entry */
 	bool                               once_per_session_set;
 	bool                               ipsc_properties_set;
 	bool                               opsc_properties_set;

driver/vidc/src/msm_vidc.c

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Copyright (c) 2020-2021, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2020-2022, The Linux Foundation. All rights reserved.
  */
 
 #include <linux/types.h>
@@ -873,6 +873,7 @@ void *msm_vidc_open(void *vidc_core, u32 session_type)
 		return NULL;
 	}
 	INIT_LIST_HEAD(&inst->response_works);
+	INIT_LIST_HEAD(&inst->caps_list);
 	INIT_LIST_HEAD(&inst->timestamps.list);
 	INIT_LIST_HEAD(&inst->ts_reorder.list);
 	INIT_LIST_HEAD(&inst->buffers.input.list);

driver/vidc/src/msm_vidc_control.c

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Copyright (c) 2020-2021, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2020-2022, The Linux Foundation. All rights reserved.
  */
 
 #include "msm_vidc_control.h"
@@ -1812,12 +1812,15 @@ int msm_vidc_adjust_dynamic_layer_bitrate(void *instance, struct v4l2_ctrl *ctrl
 	u32 old_br = 0, new_br = 0, exceeded_br = 0;
 	s32 max_bitrate;
 
-	if (!inst || !inst->capabilities || !ctrl) {
+	if (!inst || !inst->capabilities) {
 		d_vpr_e("%s: invalid params\n", __func__);
 		return -EINVAL;
 	}
 	capability = inst->capabilities;
 
+	if (!ctrl)
+		return 0;
+
 	/* ignore layer bitrate when total bitrate is set */
 	if (capability->cap[BIT_RATE].flags & CAP_FLAG_CLIENT_SET)
 		return 0;
@@ -2484,8 +2487,219 @@ int msm_vidc_adjust_roi_info(void *instance, struct v4l2_ctrl *ctrl)
 	return 0;
 }
 
+static inline bool has_parents(struct msm_vidc_inst_cap *cap)
+{
+	return !!cap->parents[0];
+}
+
+static inline bool has_childrens(struct msm_vidc_inst_cap *cap)
+{
+	return !!cap->children[0];
+}
+
+static inline bool is_root(struct msm_vidc_inst_cap *cap)
+{
+	return !has_parents(cap);
+}
+
+static inline bool is_valid_cap(struct msm_vidc_inst_cap *cap)
+{
+	return cap->cap != INST_CAP_NONE;
+}
+
+static inline bool is_all_parents_visited(
+	struct msm_vidc_inst_cap *cap, bool lookup[INST_CAP_MAX]) {
+	bool found = true;
+	int i;
+
+	for (i = 0; i < MAX_CAP_PARENTS; i++) {
+		if (cap->parents[i] == INST_CAP_NONE)
+			continue;
+
+		if (!lookup[cap->parents[i]]) {
+			found = false;
+			break;
+		}
+	}
+	return found;
+}
+
+static int add_node(
+	struct list_head *list, struct msm_vidc_inst_cap *rcap, bool lookup[INST_CAP_MAX])
+{
+	struct msm_vidc_inst_cap_entry *entry;
+
+	if (lookup[rcap->cap])
+		return 0;
+
+	entry = kzalloc(sizeof(struct msm_vidc_inst_cap_entry), GFP_KERNEL);
+	if (!entry) {
+		d_vpr_e("%s: msm_vidc_inst_cap_entry alloc failed\n", __func__);
+		return -EINVAL;
+	}
+
+	INIT_LIST_HEAD(&entry->list);
+	entry->cap_id = rcap->cap;
+	lookup[rcap->cap] = true;
+
+	list_add_tail(&entry->list, list);
+	return 0;
+}
+
+int msm_vidc_prepare_dependency_list(struct msm_vidc_inst *inst)
+{
+	struct list_head root_list, opt_list;
+	struct msm_vidc_inst_capability *capability;
+	struct msm_vidc_inst_cap *cap, *rcap;
+	struct msm_vidc_inst_cap_entry *entry = NULL, *temp = NULL;
+	bool root_visited[INST_CAP_MAX];
+	bool opt_visited[INST_CAP_MAX];
+	int tmp_count_total, tmp_count, num_nodes = 0;
+	int i, rc = 0;
+
+	if (!inst || !inst->capabilities) {
+		d_vpr_e("%s: invalid params\n", __func__);
+		return -EINVAL;
+	}
+	capability = inst->capabilities;
+
+	if (!list_empty(&inst->caps_list)) {
+		i_vpr_h(inst, "%s: dependency list already prepared\n", __func__);
+		return 0;
+	}
+
+	/* init local list and lookup table entries */
+	INIT_LIST_HEAD(&root_list);
+	INIT_LIST_HEAD(&opt_list);
+	memset(&root_visited, 0, sizeof(root_visited));
+	memset(&opt_visited, 0, sizeof(opt_visited));
+
+	/* populate root nodes first */
+	for (i = 1; i < INST_CAP_MAX; i++) {
+		rcap = &capability->cap[i];
+		if (!is_valid_cap(rcap))
+			continue;
+
+		/* sanitize cap value */
+		if (i != rcap->cap) {
+			i_vpr_e(inst, "%s: cap id mismatch. expected %s, actual %s\n",
+				__func__, cap_name(i), cap_name(rcap->cap));
+			rc = -EINVAL;
+			goto error;
+		}
+
+		/* add all root nodes */
+		if (is_root(rcap)) {
+			rc = add_node(&root_list, rcap, root_visited);
+			if (rc)
+				goto error;
+		}
+	}
+
+	/* add all dependent parents */
+	list_for_each_entry_safe(entry, temp, &root_list, list) {
+		rcap = &capability->cap[entry->cap_id];
+		/* skip leaf node */
+		if (!has_childrens(rcap))
+			continue;
+
+		for (i = 0; i < MAX_CAP_CHILDREN; i++) {
+			if (!rcap->children[i])
+				break;
+			cap = &capability->cap[rcap->children[i]];
+			if (!is_valid_cap(cap))
+				continue;
+
+			/**
+			 * if child node is already part of root or optional list
+			 * then no need to add it again.
+			 */
+			if (root_visited[cap->cap] || opt_visited[cap->cap])
+				continue;
+
+			/**
+			 * if child node's all parents are already present in root list
+			 * then add it to root list else add it to optional list.
+			 */
+			if (is_all_parents_visited(cap, root_visited)) {
+				rc = add_node(&root_list, cap, root_visited);
+				if (rc)
+					goto error;
+			} else {
+				rc = add_node(&opt_list, cap, opt_visited);
+				if (rc)
+					goto error;
+			}
+		}
+	}
+
+	/* find total optional list entries */
+	list_for_each_entry(entry, &opt_list, list)
+		num_nodes++;
+
+	/* used for loop detection */
+	tmp_count_total = num_nodes;
+	tmp_count = num_nodes;
+
+	/* sort final outstanding nodes */
+	list_for_each_entry_safe(entry, temp, &opt_list, list) {
+		/* initially remove entry from opt list */
+		list_del_init(&entry->list);
+		tmp_count--;
+		cap = &capability->cap[entry->cap_id];
+
+		/**
+		 * if all parents are visited then add this entry to
+		 * root list else add it to the end of optional list.
+		 */
+		if (is_all_parents_visited(cap, root_visited)) {
+			list_add_tail(&entry->list, &root_list);
+			root_visited[entry->cap_id] = true;
+			tmp_count_total--;
+		} else {
+			list_add_tail(&entry->list, &opt_list);
+		}
+
+		/* detect loop */
+		if (!tmp_count) {
+			if (num_nodes == tmp_count_total) {
+				i_vpr_e(inst, "%s: loop detected in subgraph %d\n",
+					__func__, num_nodes);
+				rc = -EINVAL;
+				goto error;
+			}
+			num_nodes = tmp_count_total;
+			tmp_count = tmp_count_total;
+		}
+	}
+
+	/* expecting opt_list to be empty */
+	if (!list_empty(&opt_list)) {
+		i_vpr_e(inst, "%s: opt_list is not empty\n", __func__);
+		rc = -EINVAL;
+		goto error;
+	}
+
+	/* move elements to &inst->caps_list from local */
+	list_replace_init(&root_list, &inst->caps_list);
+
+	return 0;
+error:
+	list_for_each_entry_safe(entry, temp, &opt_list, list) {
+		i_vpr_e(inst, "%s: opt_list: %s\n", __func__, cap_name(entry->cap_id));
+		list_del_init(&entry->list);
+		kfree(entry);
+	}
+	list_for_each_entry_safe(entry, temp, &root_list, list) {
+		i_vpr_e(inst, "%s: root_list: %s\n", __func__, cap_name(entry->cap_id));
+		list_del_init(&entry->list);
+		kfree(entry);
+	}
+	return rc;
+}
+
 /*
- * Loop over instance capabilities with CAP_FLAG_ROOT
+ * Loop over instance capabilities from caps_list
  * and call adjust function, where
  * - adjust current capability value
  * - update tail of instance children list with capability children
@@ -2495,7 +2709,6 @@ int msm_vidc_adjust_roi_info(void *instance, struct v4l2_ctrl *ctrl)
 int msm_vidc_adjust_v4l2_properties(struct msm_vidc_inst *inst)
 {
 	int rc = 0;
-	int i;
 	struct msm_vidc_inst_cap_entry *curr_node = NULL, *tmp_node = NULL;
 	struct msm_vidc_inst_capability *capability;
 
@@ -2506,13 +2719,12 @@ int msm_vidc_adjust_v4l2_properties(struct msm_vidc_inst *inst)
 	capability = inst->capabilities;
 
 	i_vpr_h(inst, "%s()\n", __func__);
-	for (i = 0; i < INST_CAP_MAX; i++) {
-		if (capability->cap[i].flags & CAP_FLAG_ROOT) {
-			rc = msm_vidc_adjust_property(inst,
-					capability->cap[i].cap);
-			if (rc)
-				goto exit;
-		}
+	list_for_each_entry_safe(curr_node, tmp_node, &inst->caps_list, list) {
+		i_vpr_l(inst, "%s: cap: id %3u, name %s\n", __func__,
+			curr_node->cap_id, cap_name(curr_node->cap_id));
+		rc = msm_vidc_adjust_property(inst, curr_node->cap_id);
+		if (rc)
+			goto exit;
 	}
 
 	/*

driver/vidc/src/msm_vidc_driver.c

@@ -5136,6 +5136,7 @@ void msm_vidc_destroy_buffers(struct msm_vidc_inst *inst)
 	struct msm_vidc_timestamp *ts, *dummy_ts;
 	struct msm_memory_dmabuf *dbuf, *dummy_dbuf;
 	struct response_work *work, *dummy_work = NULL;
+	struct msm_vidc_inst_cap_entry *entry, *dummy_entry;
 	static const enum msm_vidc_buffer_type ext_buf_types[] = {
 		MSM_VIDC_BUF_INPUT,
 		MSM_VIDC_BUF_OUTPUT,
@@ -5227,6 +5228,11 @@ void msm_vidc_destroy_buffers(struct msm_vidc_inst *inst)
 		kfree(work);
 	}
 
+	list_for_each_entry_safe(entry, dummy_entry, &inst->caps_list, list) {
+		list_del(&entry->list);
+		kfree(entry);
+	}
+
 	/* destroy buffers from pool */
 	msm_memory_pools_deinit(inst);
 }

driver/vidc/src/msm_vidc_vb2.c

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Copyright (c) 2020-2021, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2020-2022, The Linux Foundation. All rights reserved.
  */
 
 #include "msm_vidc_vb2.h"
@@ -190,6 +190,10 @@ int msm_vidc_start_streaming(struct vb2_queue *q, unsigned int count)
 
 	if (!inst->once_per_session_set) {
 		inst->once_per_session_set = true;
+		rc = msm_vidc_prepare_dependency_list(inst);
+		if (rc)
+			return rc;
+
 		rc = msm_vidc_session_set_codec(inst);
 		if (rc)
 			return rc;