From 877e7b7c3b12d78f0488b767ed10ec21166ee422 Mon Sep 17 00:00:00 2001 From: Colin Foster Date: Sat, 19 Nov 2022 15:14:06 -0800 Subject: [PATCH] net: mscc: ocelot: issue a warning if stats are incorrectly ordered Ocelot uses regmap_bulk_read() operations to efficiently read stats registers. Currently the implementation relies on the stats layout to be ordered to be most efficient. Issue a warning if any future implementations happen to break this pattern. Signed-off-by: Colin Foster Co-developed-by: Vladimir Oltean Reviewed-by: Vladimir Oltean Signed-off-by: Paolo Abeni --- drivers/net/ethernet/mscc/ocelot_stats.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/mscc/ocelot_stats.c b/drivers/net/ethernet/mscc/ocelot_stats.c index 68e9f450c468..1478c3b21af1 100644 --- a/drivers/net/ethernet/mscc/ocelot_stats.c +++ b/drivers/net/ethernet/mscc/ocelot_stats.c @@ -602,7 +602,7 @@ EXPORT_SYMBOL(ocelot_port_get_stats64); static int ocelot_prepare_stats_regions(struct ocelot *ocelot) { struct ocelot_stats_region *region = NULL; - unsigned int last; + unsigned int last = 0; int i; INIT_LIST_HEAD(&ocelot->stats_regions); @@ -619,6 +619,12 @@ static int ocelot_prepare_stats_regions(struct ocelot *ocelot) if (!region) return -ENOMEM; + /* enum ocelot_stat must be kept sorted in the same + * order as ocelot_stats_layout[i].reg in order to have + * efficient bulking + */ + WARN_ON(last >= ocelot_stats_layout[i].reg); + region->base = ocelot_stats_layout[i].reg; region->count = 1; list_add_tail(®ion->node, &ocelot->stats_regions);