net/mlx5: Allocate command stats with xarray

Command stats is an array with more than 2K entries, which amounts to
~180KB. This is way more than actually needed, as only ~190 entries
are being used.

Therefore, replace the array with xarray.
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/cmd.c

@@ -1225,8 +1225,8 @@ static int mlx5_cmd_invoke(struct mlx5_core_dev *dev, struct mlx5_cmd_msg *in,
 		goto out_free;
 
 	ds = ent->ts2 - ent->ts1;
-	if (ent->op < MLX5_CMD_OP_MAX) {
-		stats = &cmd->stats[ent->op];
+	stats = xa_load(&cmd->stats, ent->op);
+	if (stats) {
 		spin_lock_irq(&stats->lock);
 		stats->sum += ds;
 		++stats->n;
@@ -1695,8 +1695,8 @@ static void mlx5_cmd_comp_handler(struct mlx5_core_dev *dev, u64 vec, bool force
 
 			if (ent->callback) {
 				ds = ent->ts2 - ent->ts1;
-				if (ent->op < MLX5_CMD_OP_MAX) {
-					stats = &cmd->stats[ent->op];
+				stats = xa_load(&cmd->stats, ent->op);
+				if (stats) {
 					spin_lock_irqsave(&stats->lock, flags);
 					stats->sum += ds;
 					++stats->n;
@@ -1923,7 +1923,9 @@ static void cmd_status_log(struct mlx5_core_dev *dev, u16 opcode, u8 status,
 	if (!err || !(strcmp(namep, "unknown command opcode")))
 		return;
 
-	stats = &dev->cmd.stats[opcode];
+	stats = xa_load(&dev->cmd.stats, opcode);
+	if (!stats)
+		return;
 	spin_lock_irq(&stats->lock);
 	stats->failed++;
 	if (err < 0)
@@ -2189,7 +2191,6 @@ int mlx5_cmd_init(struct mlx5_core_dev *dev)
 	struct mlx5_cmd *cmd = &dev->cmd;
 	u32 cmd_l;
 	int err;
-	int i;
 
 	cmd->pool = dma_pool_create("mlx5_cmd", mlx5_core_dma_dev(dev), size, align, 0);
 	if (!cmd->pool)
@@ -2209,8 +2210,6 @@ int mlx5_cmd_init(struct mlx5_core_dev *dev)
 
 	spin_lock_init(&cmd->alloc_lock);
 	spin_lock_init(&cmd->token_lock);
-	for (i = 0; i < MLX5_CMD_OP_MAX; i++)
-		spin_lock_init(&cmd->stats[i].lock);
 
 	create_msg_cache(dev);
 

drivers/net/ethernet/mellanox/mlx5/core/debugfs.c

@@ -188,6 +188,24 @@ static const struct file_operations slots_fops = {
 	.read	= slots_read,
 };
 
+static struct mlx5_cmd_stats *
+mlx5_cmdif_alloc_stats(struct xarray *stats_xa, int opcode)
+{
+	struct mlx5_cmd_stats *stats = kzalloc(sizeof(*stats), GFP_KERNEL);
+	int err;
+
+	if (!stats)
+		return NULL;
+
+	err = xa_insert(stats_xa, opcode, stats, GFP_KERNEL);
+	if (err) {
+		kfree(stats);
+		return NULL;
+	}
+	spin_lock_init(&stats->lock);
+	return stats;
+}
+
 void mlx5_cmdif_debugfs_init(struct mlx5_core_dev *dev)
 {
 	struct mlx5_cmd_stats *stats;
@@ -200,10 +218,14 @@ void mlx5_cmdif_debugfs_init(struct mlx5_core_dev *dev)
 
 	debugfs_create_file("slots_inuse", 0400, *cmd, &dev->cmd, &slots_fops);
 
+	xa_init(&dev->cmd.stats);
+
 	for (i = 0; i < MLX5_CMD_OP_MAX; i++) {
-		stats = &dev->cmd.stats[i];
 		namep = mlx5_command_str(i);
 		if (strcmp(namep, "unknown command opcode")) {
+			stats = mlx5_cmdif_alloc_stats(&dev->cmd.stats, i);
+			if (!stats)
+				continue;
 			stats->root = debugfs_create_dir(namep, *cmd);
 
 			debugfs_create_file("average", 0400, stats->root, stats,
@@ -224,7 +246,13 @@ void mlx5_cmdif_debugfs_init(struct mlx5_core_dev *dev)
 
 void mlx5_cmdif_debugfs_cleanup(struct mlx5_core_dev *dev)
 {
+	struct mlx5_cmd_stats *stats;
+	unsigned long i;
+
 	debugfs_remove_recursive(dev->priv.dbg.cmdif_debugfs);
+	xa_for_each(&dev->cmd.stats, i, stats)
+		kfree(stats);
+	xa_destroy(&dev->cmd.stats);
 }
 
 void mlx5_cq_debugfs_init(struct mlx5_core_dev *dev)

include/linux/mlx5/driver.h

@@ -322,7 +322,7 @@ struct mlx5_cmd {
 	struct mlx5_cmd_debug dbg;
 	struct cmd_msg_cache cache[MLX5_NUM_COMMAND_CACHES];
 	int checksum_disabled;
-	struct mlx5_cmd_stats stats[MLX5_CMD_OP_MAX];
+	struct xarray stats;
 };
 
 struct mlx5_cmd_mailbox {