net: mvpp2: debugfs: Store debugfs entries data in mvpp2 struct

The current way to store the required private data needed to access
various debugfs entries is to alloc them on the fly, share them within
the entries that need to access them, and finally have one entry free
that data upon closing. This leads to hard to maintain code, and is very
error-prone.

This commit stores all debugfs related data in the same place, making
sure this is allocated only when the debugfs directory is successfully
created, so that we don't waste memory when we don't use this feature.
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/mvpp2/mvpp2.h

@@ -714,6 +714,7 @@ enum mvpp2_prs_l3_cast {
 #define MVPP2_DESC_DMA_MASK	DMA_BIT_MASK(40)
 
 /* Definitions */
+struct mvpp2_dbgfs_entries;
 
 /* Shared Packet Processor resources */
 struct mvpp2 {
@@ -775,6 +776,9 @@ struct mvpp2 {
 
 	/* Debugfs root entry */
 	struct dentry *dbgfs_dir;
+
+	/* Debugfs entries private data */
+	struct mvpp2_dbgfs_entries *dbgfs_entries;
 };
 
 struct mvpp2_pcpu_stats {

drivers/net/ethernet/marvell/mvpp2/mvpp2_debugfs.c

@@ -28,6 +28,17 @@ struct mvpp2_dbgfs_port_flow_entry {
 	struct mvpp2_dbgfs_flow_entry *dbg_fe;
 };
 
+struct mvpp2_dbgfs_entries {
+	/* Entries for Header Parser debug info */
+	struct mvpp2_dbgfs_prs_entry prs_entries[MVPP2_PRS_TCAM_SRAM_SIZE];
+
+	/* Entries for Classifier flows debug info */
+	struct mvpp2_dbgfs_flow_entry flow_entries[MVPP2_N_PRS_FLOWS];
+
+	/* Entries for per-port flows debug info */
+	struct mvpp2_dbgfs_port_flow_entry port_flow_entries[MVPP2_MAX_PORTS];
+};
+
 static int mvpp2_dbgfs_flow_flt_hits_show(struct seq_file *s, void *unused)
 {
 	struct mvpp2_dbgfs_flow_entry *entry = s->private;
@@ -93,25 +104,7 @@ static int mvpp2_dbgfs_flow_type_show(struct seq_file *s, void *unused)
 	return 0;
 }
 
-static int mvpp2_dbgfs_flow_type_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, mvpp2_dbgfs_flow_type_show, inode->i_private);
-}
-
-static int mvpp2_dbgfs_flow_type_release(struct inode *inode, struct file *file)
-{
-	struct seq_file *seq = file->private_data;
-	struct mvpp2_dbgfs_flow_entry *flow_entry = seq->private;
-
-	kfree(flow_entry);
-	return single_release(inode, file);
-}
-
-static const struct file_operations mvpp2_dbgfs_flow_type_fops = {
-	.open = mvpp2_dbgfs_flow_type_open,
-	.read = seq_read,
-	.release = mvpp2_dbgfs_flow_type_release,
-};
+DEFINE_SHOW_ATTRIBUTE(mvpp2_dbgfs_flow_type);
 
 static int mvpp2_dbgfs_flow_id_show(struct seq_file *s, void *unused)
 {
@@ -153,28 +146,7 @@ static int mvpp2_dbgfs_port_flow_hash_opt_show(struct seq_file *s, void *unused)
 	return 0;
 }
 
-static int mvpp2_dbgfs_port_flow_hash_opt_open(struct inode *inode,
-					       struct file *file)
-{
-	return single_open(file, mvpp2_dbgfs_port_flow_hash_opt_show,
-			   inode->i_private);
-}
-
-static int mvpp2_dbgfs_port_flow_hash_opt_release(struct inode *inode,
-						  struct file *file)
-{
-	struct seq_file *seq = file->private_data;
-	struct mvpp2_dbgfs_port_flow_entry *flow_entry = seq->private;
-
-	kfree(flow_entry);
-	return single_release(inode, file);
-}
-
-static const struct file_operations mvpp2_dbgfs_port_flow_hash_opt_fops = {
-	.open = mvpp2_dbgfs_port_flow_hash_opt_open,
-	.read = seq_read,
-	.release = mvpp2_dbgfs_port_flow_hash_opt_release,
-};
+DEFINE_SHOW_ATTRIBUTE(mvpp2_dbgfs_port_flow_hash_opt);
 
 static int mvpp2_dbgfs_port_flow_engine_show(struct seq_file *s, void *unused)
 {
@@ -456,25 +428,7 @@ static int mvpp2_dbgfs_prs_valid_show(struct seq_file *s, void *unused)
 	return 0;
 }
 
-static int mvpp2_dbgfs_prs_valid_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, mvpp2_dbgfs_prs_valid_show, inode->i_private);
-}
-
-static int mvpp2_dbgfs_prs_valid_release(struct inode *inode, struct file *file)
-{
-	struct seq_file *seq = file->private_data;
-	struct mvpp2_dbgfs_prs_entry *entry = seq->private;
-
-	kfree(entry);
-	return single_release(inode, file);
-}
-
-static const struct file_operations mvpp2_dbgfs_prs_valid_fops = {
-	.open = mvpp2_dbgfs_prs_valid_open,
-	.read = seq_read,
-	.release = mvpp2_dbgfs_prs_valid_release,
-};
+DEFINE_SHOW_ATTRIBUTE(mvpp2_dbgfs_prs_valid);
 
 static int mvpp2_dbgfs_flow_port_init(struct dentry *parent,
 				      struct mvpp2_port *port,
@@ -487,10 +441,7 @@ static int mvpp2_dbgfs_flow_port_init(struct dentry *parent,
 	if (IS_ERR(port_dir))
 		return PTR_ERR(port_dir);
 
-	/* This will be freed by 'hash_opts' release op */
-	port_entry = kmalloc(sizeof(*port_entry), GFP_KERNEL);
-	if (!port_entry)
-		return -ENOMEM;
+	port_entry = &port->priv->dbgfs_entries->port_flow_entries[port->id];
 
 	port_entry->port = port;
 	port_entry->dbg_fe = entry;
@@ -518,10 +469,7 @@ static int mvpp2_dbgfs_flow_entry_init(struct dentry *parent,
 	if (!flow_entry_dir)
 		return -ENOMEM;
 
-	/* This will be freed by 'type' release op */
-	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
-	if (!entry)
-		return -ENOMEM;
+	entry = &priv->dbgfs_entries->flow_entries[flow];
 
 	entry->flow = flow;
 	entry->priv = priv;
@@ -582,10 +530,7 @@ static int mvpp2_dbgfs_prs_entry_init(struct dentry *parent,
 	if (!prs_entry_dir)
 		return -ENOMEM;
 
-	/* The 'valid' entry's ops will free that */
-	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
-	if (!entry)
-		return -ENOMEM;
+	entry = &priv->dbgfs_entries->prs_entries[tid];
 
 	entry->tid = tid;
 	entry->priv = priv;
@@ -663,6 +608,8 @@ static int mvpp2_dbgfs_port_init(struct dentry *parent,
 void mvpp2_dbgfs_cleanup(struct mvpp2 *priv)
 {
 	debugfs_remove_recursive(priv->dbgfs_dir);
+
+	kfree(priv->dbgfs_entries);
 }
 
 void mvpp2_dbgfs_init(struct mvpp2 *priv, const char *name)
@@ -682,6 +629,9 @@ void mvpp2_dbgfs_init(struct mvpp2 *priv, const char *name)
 		return;
 
 	priv->dbgfs_dir = mvpp2_dir;
+	priv->dbgfs_entries = kzalloc(sizeof(*priv->dbgfs_entries), GFP_KERNEL);
+	if (!priv->dbgfs_entries)
+		goto err;
 
 	ret = mvpp2_dbgfs_prs_init(mvpp2_dir, priv);
 	if (ret)