net/smc: Add SMC statistics support

Add the ability to collect SMC statistics information. Per-cpu
variables are used to collect the statistic information for better
performance and for reducing concurrency pitfalls. The code that is
collecting statistic data is implemented in macros to increase code
reuse and readability.

Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 35 insertions, 0 deletions

diff --git a/net/smc/smc_stats.c b/net/smc/smc_stats.c
new file mode 100644
index 000000000000..76e938388520
--- /dev/null
+++ b/net/smc/smc_stats.c
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Shared Memory Communications over RDMA (SMC-R) and RoCE
+ *
+ * SMC statistics netlink routines
+ *
+ * Copyright IBM Corp. 2021
+ *
+ * Author(s):  Guvenc Gulce
+ */
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/percpu.h>
+#include <linux/ctype.h>
+#include "smc_stats.h"
+
+/* serialize fallback reason statistic gathering */
+DEFINE_MUTEX(smc_stat_fback_rsn);
+struct smc_stats __percpu *smc_stats;	/* per cpu counters for SMC */
+struct smc_stats_reason fback_rsn;
+
+int __init smc_stats_init(void)
+{
+	memset(&fback_rsn, 0, sizeof(fback_rsn));
+	smc_stats = alloc_percpu(struct smc_stats);
+	if (!smc_stats)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void smc_stats_exit(void)
+{
+	free_percpu(smc_stats);
+}