diff mbox series

[v1,net-next,2/2] net: mscc: ocelot: use bulk reads for stats

Message ID 20220110010618.428927-3-colin.foster@in-advantage.com (mailing list archive)
State Deferred
Delegated to: Netdev Maintainers
Headers show
Series use bulk reads for ocelot statistics | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers success CCed 7 of 7 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch warning WARNING: line length of 82 exceeds 80 columns WARNING: line length of 88 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Colin Foster Jan. 10, 2022, 1:06 a.m. UTC
Create and utilize bulk regmap reads instead of single access for gathering
stats. This will allow slower buses (SPI) the ability to drop significant
overhead performing new transactions that could instead be sequential
access.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
---
 drivers/net/ethernet/mscc/ocelot.c | 76 +++++++++++++++++++++++++-----
 include/soc/mscc/ocelot.h          |  8 ++++
 2 files changed, 71 insertions(+), 13 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
index 9b42187a026a..57b40de9fcdc 100644
--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -1697,32 +1697,40 @@  void ocelot_get_strings(struct ocelot *ocelot, int port, u32 sset, u8 *data)
 }
 EXPORT_SYMBOL(ocelot_get_strings);
 
-static void ocelot_update_stats(struct ocelot *ocelot)
+static int ocelot_update_stats(struct ocelot *ocelot)
 {
-	int i, j;
+	struct ocelot_stats_region *region;
+	int i, j, err = 0;
 
 	mutex_lock(&ocelot->stats_lock);
 
 	for (i = 0; i < ocelot->num_phys_ports; i++) {
+		unsigned int idx = 0;
 		/* Configure the port to read the stats from */
 		ocelot_write(ocelot, SYS_STAT_CFG_STAT_VIEW(i), SYS_STAT_CFG);
 
-		for (j = 0; j < ocelot->num_stats; j++) {
-			u32 val;
-			unsigned int idx = i * ocelot->num_stats + j;
+		list_for_each_entry(region, &ocelot->stats_regions, node) {
+			err = ocelot_bulk_read_rix(ocelot, SYS_COUNT_RX_OCTETS,
+						   region->offset, region->buf,
+						   region->count);
+			if (err)
+				goto out;
 
-			val = ocelot_read_rix(ocelot, SYS_COUNT_RX_OCTETS,
-					      ocelot->stats_layout[j].offset);
+			for (j = 0; j < region->count; j++) {
+				if (region->buf[j] < (ocelot->stats[idx + j] & U32_MAX))
+					ocelot->stats[idx + j] += (u64)1 << 32;
 
-			if (val < (ocelot->stats[idx] & U32_MAX))
-				ocelot->stats[idx] += (u64)1 << 32;
+				ocelot->stats[idx + j] = (ocelot->stats[idx + j] &
+							~(u64)U32_MAX) + region->buf[j];
+			}
 
-			ocelot->stats[idx] = (ocelot->stats[idx] &
-					      ~(u64)U32_MAX) + val;
+			idx += region->count;
 		}
 	}
 
+out:
 	mutex_unlock(&ocelot->stats_lock);
+	return err;
 }
 
 static void ocelot_check_stats_work(struct work_struct *work)
@@ -1739,10 +1747,11 @@  static void ocelot_check_stats_work(struct work_struct *work)
 
 void ocelot_get_ethtool_stats(struct ocelot *ocelot, int port, u64 *data)
 {
-	int i;
+	int i, err;
 
 	/* check and update now */
-	ocelot_update_stats(ocelot);
+	err = ocelot_update_stats(ocelot);
+	WARN_ONCE(err, "Error %d updating ethtool stats\n", err);
 
 	/* Copy all counters */
 	for (i = 0; i < ocelot->num_stats; i++)
@@ -1759,6 +1768,43 @@  int ocelot_get_sset_count(struct ocelot *ocelot, int port, int sset)
 }
 EXPORT_SYMBOL(ocelot_get_sset_count);
 
+static int ocelot_prepare_stats_regions(struct ocelot *ocelot)
+{
+	struct ocelot_stats_region *region = NULL;
+	unsigned int last;
+	int i;
+
+	INIT_LIST_HEAD(&ocelot->stats_regions);
+
+	for (i = 0; i < ocelot->num_stats; i++) {
+		if (region && ocelot->stats_layout[i].offset == last + 1) {
+			region->count++;
+		} else {
+			region = devm_kzalloc(ocelot->dev, sizeof(*region),
+					      GFP_KERNEL);
+			if (!region)
+				return -ENOMEM;
+
+			region->offset = ocelot->stats_layout[i].offset;
+			region->count = 1;
+			list_add_tail(&region->node, &ocelot->stats_regions);
+		}
+
+		last = ocelot->stats_layout[i].offset;
+	}
+
+	list_for_each_entry(region, &ocelot->stats_regions, node) {
+		region->buf = devm_kzalloc(ocelot->dev,
+					   region->count * sizeof(*region->buf),
+					   GFP_KERNEL);
+
+		if (!region->buf)
+			return -ENOMEM;
+	}
+
+	return 0;
+}
+
 int ocelot_get_ts_info(struct ocelot *ocelot, int port,
 		       struct ethtool_ts_info *info)
 {
@@ -2763,6 +2809,10 @@  int ocelot_init(struct ocelot *ocelot)
 				 ANA_CPUQ_8021_CFG_CPUQ_BPDU_VAL(6),
 				 ANA_CPUQ_8021_CFG, i);
 
+	ret = ocelot_prepare_stats_regions(ocelot);
+	if (ret)
+		return ret;
+
 	INIT_DELAYED_WORK(&ocelot->stats_work, ocelot_check_stats_work);
 	queue_delayed_work(ocelot->stats_queue, &ocelot->stats_work,
 			   OCELOT_STATS_CHECK_DELAY);
diff --git a/include/soc/mscc/ocelot.h b/include/soc/mscc/ocelot.h
index 6f74015032fc..1f11c27bf29f 100644
--- a/include/soc/mscc/ocelot.h
+++ b/include/soc/mscc/ocelot.h
@@ -542,6 +542,13 @@  struct ocelot_stat_layout {
 	char name[ETH_GSTRING_LEN];
 };
 
+struct ocelot_stats_region {
+	struct list_head node;
+	u32 offset;
+	int count;
+	u32 *buf;
+};
+
 enum ocelot_tag_prefix {
 	OCELOT_TAG_PREFIX_DISABLED	= 0,
 	OCELOT_TAG_PREFIX_NONE,
@@ -673,6 +680,7 @@  struct ocelot {
 	struct regmap_field		*regfields[REGFIELD_MAX];
 	const u32 *const		*map;
 	const struct ocelot_stat_layout	*stats_layout;
+	struct list_head		stats_regions;
 	unsigned int			num_stats;
 
 	u32				pool_size[OCELOT_SB_NUM][OCELOT_SB_POOL_NUM];