[PATCH net-next 8/8] net: mscc: ocelot: fix ineffective WARN_ON() in ocelot_stats.c

From: Vladimir Oltean
Date: Wed Apr 12 2023 - 08:50:43 EST


Since it is hopefully now clear that, since "last" and "layout[i].reg"
are enum types and not addresses, the existing WARN_ON() is ineffective
in checking that the _addresses_ are sorted in the proper order.

Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
---
drivers/net/ethernet/mscc/ocelot_stats.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/mscc/ocelot_stats.c b/drivers/net/ethernet/mscc/ocelot_stats.c
index e82c9d9d0ad3..5c55197c7327 100644
--- a/drivers/net/ethernet/mscc/ocelot_stats.c
+++ b/drivers/net/ethernet/mscc/ocelot_stats.c
@@ -901,6 +901,17 @@ static int ocelot_prepare_stats_regions(struct ocelot *ocelot)
if (!layout[i].reg)
continue;

+ /* enum ocelot_stat must be kept sorted in the same order
+ * as the addresses behind layout[i].reg in order to have
+ * efficient bulking
+ */
+ if (last) {
+ WARN(ocelot->map[SYS][last & REG_MASK] >= ocelot->map[SYS][layout[i].reg & REG_MASK],
+ "reg 0x%x had address 0x%x but reg 0x%x has address 0x%x, bulking broken!",
+ last, ocelot->map[SYS][last & REG_MASK],
+ layout[i].reg, ocelot->map[SYS][layout[i].reg & REG_MASK]);
+ }
+
if (region && ocelot->map[SYS][layout[i].reg & REG_MASK] ==
ocelot->map[SYS][last & REG_MASK] + 4) {
region->count++;
@@ -910,12 +921,6 @@ 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 layout[i].reg in order to have efficient
- * bulking
- */
- WARN_ON(last >= layout[i].reg);
-
region->base = layout[i].reg;
region->first_stat = i;
region->count = 1;
--
2.34.1