[PATCH v5 2/9] ethdev: add common counters for statistics

[Stephen Hemminger <stephen@networkplumber.org>]

Introduce common helper routines for keeping track of per-queue
statistics in SW PMD's. The code in several drivers had
copy/pasted the same code for this, but had common issues
with 64 bit counters on 32 bit platforms.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 lib/ethdev/ethdev_swstats.c | 109 +++++++++++++++++++++++++++++++
 lib/ethdev/ethdev_swstats.h | 124 ++++++++++++++++++++++++++++++++++++
 lib/ethdev/meson.build      |   2 +
 lib/ethdev/version.map      |   3 +
 4 files changed, 238 insertions(+)
 create mode 100644 lib/ethdev/ethdev_swstats.c
 create mode 100644 lib/ethdev/ethdev_swstats.h

diff --git a/lib/ethdev/ethdev_swstats.c b/lib/ethdev/ethdev_swstats.c
new file mode 100644
index 0000000000..7892b2180b
--- /dev/null
+++ b/lib/ethdev/ethdev_swstats.c
@@ -0,0 +1,109 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright (c) Stephen Hemminger <stephen@networkplumber.org>
+ */
+
+
+#include <rte_config.h>
+#include <rte_common.h>
+#include <rte_atomic.h>
+
+#include "rte_ethdev.h"
+#include "ethdev_driver.h"
+#include "ethdev_swstats.h"
+
+int
+rte_eth_counters_stats_get(const struct rte_eth_dev *dev,
+			   size_t tx_offset, size_t rx_offset,
+			   struct rte_eth_stats *stats)
+{
+	uint64_t packets, bytes, errors;
+	unsigned int i;
+
+	for (i = 0; i < dev->data->nb_tx_queues; i++) {
+		const void *txq = dev->data->tx_queues[i];
+		const struct rte_eth_counters *counters;
+
+		if (txq == NULL)
+			continue;
+
+		counters = (const struct rte_eth_counters *)((const char *)txq + tx_offset);
+		packets = rte_counter64_fetch(&counters->packets);
+		bytes = rte_counter64_fetch(&counters->bytes);
+		errors = rte_counter64_fetch(&counters->errors);
+
+		/*
+		 * Prevent compiler from fetching values twice which would
+		 * cause per-queue and global statistics to not match.
+		 */
+		rte_compiler_barrier();
+
+		stats->opackets += packets;
+		stats->obytes += bytes;
+		stats->oerrors += errors;
+
+		if (i < RTE_ETHDEV_QUEUE_STAT_CNTRS) {
+			stats->q_opackets[i] = packets;
+			stats->q_obytes[i] = bytes;
+		}
+	}
+
+	for (i = 0; i < dev->data->nb_rx_queues; i++) {
+		const void *rxq = dev->data->rx_queues[i];
+		const struct rte_eth_counters *counters;
+
+		if (rxq == NULL)
+			continue;
+
+		counters = (const struct rte_eth_counters *)((const char *)rxq + rx_offset);
+		packets = rte_counter64_fetch(&counters->packets);
+		bytes = rte_counter64_fetch(&counters->bytes);
+		errors = rte_counter64_fetch(&counters->errors);
+
+		rte_compiler_barrier();
+
+		stats->ipackets += packets;
+		stats->ibytes += bytes;
+		stats->ierrors += errors;
+
+		if (i < RTE_ETHDEV_QUEUE_STAT_CNTRS) {
+			stats->q_ipackets[i] = packets;
+			stats->q_ibytes[i] = bytes;
+		}
+	}
+
+	stats->rx_nombuf = dev->data->rx_mbuf_alloc_failed;
+	return 0;
+}
+
+int
+rte_eth_counters_reset(struct rte_eth_dev *dev, size_t tx_offset, size_t rx_offset)
+{
+	struct rte_eth_counters *counters;
+	unsigned int i;
+
+	for (i = 0; i < dev->data->nb_tx_queues; i++) {
+		void *txq  = dev->data->tx_queues[i];
+
+		if (txq == NULL)
+			continue;
+
+		counters = (struct rte_eth_counters *)((char *)txq + tx_offset);
+		rte_counter64_reset(&counters->packets);
+		rte_counter64_reset(&counters->bytes);
+		rte_counter64_reset(&counters->errors);
+	}
+
+	for (i = 0; i < dev->data->nb_rx_queues; i++) {
+		void *rxq  = dev->data->rx_queues[i];
+
+		if (rxq == NULL)
+			continue;
+
+		counters = (struct rte_eth_counters *)((char *)rxq + rx_offset);
+		rte_counter64_reset(&counters->packets);
+		rte_counter64_reset(&counters->bytes);
+		rte_counter64_reset(&counters->errors);
+	}
+
+	return 0;
+}
diff --git a/lib/ethdev/ethdev_swstats.h b/lib/ethdev/ethdev_swstats.h
new file mode 100644
index 0000000000..808c540640
--- /dev/null
+++ b/lib/ethdev/ethdev_swstats.h
@@ -0,0 +1,124 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright (c) Stephen Hemminger <stephen@networkplumber.org>
+ */
+
+#ifndef _RTE_ETHDEV_SWSTATS_H_
+#define _RTE_ETHDEV_SWSTATS_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @file
+ *
+ * Internal statistics counters for software based devices.
+ * Hardware PMD's should use the hardware counters instead.
+ *
+ * This provides a library for PMD's to keep track of packets and bytes.
+ * It is assumed that this will be used per queue and queues are not
+ * shared by lcores.
+ */
+
+#include <rte_counter.h>
+
+/**
+ * A structure to be embedded in the device driver per-queue data.
+ */
+struct rte_eth_counters {
+	rte_counter64_t	packets;	/**< Total number of packets. */
+	rte_counter64_t	bytes;		/**< Total number of bytes. */
+	rte_counter64_t	errors;		/**< Total number of packets with errors. */
+};
+
+/**
+ * @internal
+ * Increment counters for a single packet.
+ *
+ * @param counters
+ *    Pointer to queue structure containing counters.
+ * @param sz
+ *    Size of the packet in bytes.
+ */
+__rte_internal
+static inline void
+rte_eth_count_packet(struct rte_eth_counters *counters, uint32_t sz)
+{
+	rte_counter64_add(&counters->packets, 1);
+	rte_counter64_add(&counters->bytes, sz);
+}
+
+/**
+ * @internal
+ * Increment counters based on mbuf.
+ *
+ * @param counters
+ *    Pointer to queue structure containing counters.
+ * @param mbuf
+ *    Received or transmitted mbuf.
+ */
+__rte_internal
+static inline void
+rte_eth_count_mbuf(struct rte_eth_counters *counters, const struct rte_mbuf *mbuf)
+{
+	rte_eth_count_packet(counters, rte_pktmbuf_pkt_len(mbuf));
+}
+
+/**
+ * @internal
+ * Increment error counter.
+ *
+ * @param counters
+ *    Pointer to queue structure containing counters.
+ */
+__rte_internal
+static inline void
+rte_eth_count_error(struct rte_eth_counters *counters)
+{
+	rte_counter64_add(&counters->errors, 1);
+}
+
+/**
+ * @internal
+ * Retrieve the general statistics for all queues.
+ * @see rte_eth_stats_get.
+ *
+ * @param dev
+ *    Pointer to the Ethernet device structure.
+ * @param tx_offset
+ *    Offset from the tx_queue structure where stats are located.
+ * @param rx_offset
+ *    Offset from the rx_queue structure where stats are located.
+ * @param stats
+ *   A pointer to a structure of type *rte_eth_stats* to be filled
+ * @return
+ *   Zero if successful. Non-zero otherwise.
+ */
+__rte_internal
+int rte_eth_counters_stats_get(const struct rte_eth_dev *dev,
+			       size_t tx_offset, size_t rx_offset,
+			       struct rte_eth_stats *stats);
+
+/**
+ * @internal
+ * Reset the statistics for all queues.
+ * @see rte_eth_stats_reset.
+ *
+ * @param dev
+ *    Pointer to the Ethernet device structure.
+ * @param tx_offset
+ *    Offset from the tx_queue structure where stats are located.
+ * @param rx_offset
+ *    Offset from the rx_queue structure where stats are located.
+ * @return
+ *   Zero if successful. Non-zero otherwise.
+ */
+__rte_internal
+int rte_eth_counters_reset(struct rte_eth_dev *dev,
+			   size_t tx_offset, size_t rx_offset);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _RTE_ETHDEV_SWSTATS_H_ */
diff --git a/lib/ethdev/meson.build b/lib/ethdev/meson.build
index f1d2586591..7ce29a46d4 100644
--- a/lib/ethdev/meson.build
+++ b/lib/ethdev/meson.build
@@ -3,6 +3,7 @@
 
 sources = files(
         'ethdev_driver.c',
+        'ethdev_swstats.c',
         'ethdev_private.c',
         'ethdev_profile.c',
         'ethdev_trace_points.c',
@@ -42,6 +43,7 @@ driver_sdk_headers += files(
         'ethdev_driver.h',
         'ethdev_pci.h',
         'ethdev_vdev.h',
+        'ethdev_swstats.h',
 )
 
 if is_linux
diff --git a/lib/ethdev/version.map b/lib/ethdev/version.map
index 79f6f5293b..fc595be278 100644
--- a/lib/ethdev/version.map
+++ b/lib/ethdev/version.map
@@ -358,4 +358,7 @@ INTERNAL {
 	rte_eth_switch_domain_alloc;
 	rte_eth_switch_domain_free;
 	rte_flow_fp_default_ops;
+
+	rte_eth_counters_reset;
+	rte_eth_counters_stats_get;
 };
-- 
2.43.0