[PATCH v5 net-next 14/15] net: dsa: mv88e6xxx: Export STU as devlink region

Tobias Waldekranz
2022-03-16T15:10:41Z

Export the raw STU data in a devlink region so that it can be
inspected from userspace and compared to the current bridge
configuration.

Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
---
drivers/net/dsa/mv88e6xxx/chip.h | 1 +
drivers/net/dsa/mv88e6xxx/devlink.c | 94 +++++++++++++++++++++++++++++
2 files changed, 95 insertions(+)

diff --git a/drivers/net/dsa/mv88e6xxx/chip.h b/drivers/net/dsa/mv88e6xxx/chip.h
index be654be69982..6d4daa24d3e5 100644
--- a/drivers/net/dsa/mv88e6xxx/chip.h
+++ b/drivers/net/dsa/mv88e6xxx/chip.h
@@ -287,6 +287,7 @@ enum mv88e6xxx_region_id {
MV88E6XXX_REGION_GLOBAL2,
MV88E6XXX_REGION_ATU,
MV88E6XXX_REGION_VTU,
+ MV88E6XXX_REGION_STU,
MV88E6XXX_REGION_PVT,

_MV88E6XXX_REGION_MAX,
diff --git a/drivers/net/dsa/mv88e6xxx/devlink.c b/drivers/net/dsa/mv88e6xxx/devlink.c
index 381068395c63..1266eabee086 100644
--- a/drivers/net/dsa/mv88e6xxx/devlink.c
+++ b/drivers/net/dsa/mv88e6xxx/devlink.c
@@ -503,6 +503,85 @@ static int mv88e6xxx_region_vtu_snapshot(struct devlink *dl,
return 0;
}

+/**
+ * struct mv88e6xxx_devlink_stu_entry - Devlink STU entry
+ * @sid: Global1/3: SID, unknown filters and learning.
+ * @vid: Global1/6: Valid bit.
+ * @data: Global1/7-9: Membership data and priority override.
+ * @resvd: Reserved. In case we forgot something.
+ *
+ * The STU entry format varies between chipset generations. Peridot
+ * and Amethyst packs the STU data into Global1/7-8. Older silicon
+ * spreads the information across all three VTU data registers -
+ * inheriting the layout of even older hardware that had no STU at
+ * all. Since this is a low-level debug interface, copy all data
+ * verbatim and defer parsing to the consumer.
+ */
+struct mv88e6xxx_devlink_stu_entry {
+ u16 sid;
+ u16 vid;
+ u16 data[3];
+ u16 resvd;
+};
+
+static int mv88e6xxx_region_stu_snapshot(struct devlink *dl,
+ const struct devlink_region_ops *ops,
+ struct netlink_ext_ack *extack,
+ u8 **data)
+{
+ struct mv88e6xxx_devlink_stu_entry *table, *entry;
+ struct dsa_switch *ds = dsa_devlink_to_ds(dl);
+ struct mv88e6xxx_chip *chip = ds->priv;
+ struct mv88e6xxx_stu_entry stu;
+ int err;
+
+ table = kcalloc(mv88e6xxx_max_sid(chip) + 1,
+ sizeof(struct mv88e6xxx_devlink_stu_entry),
+ GFP_KERNEL);
+ if (!table)
+ return -ENOMEM;
+
+ entry = table;
+ stu.sid = mv88e6xxx_max_sid(chip);
+ stu.valid = false;
+
+ mv88e6xxx_reg_lock(chip);
+
+ do {
+ err = mv88e6xxx_g1_stu_getnext(chip, &stu);
+ if (err)
+ break;
+
+ if (!stu.valid)
+ break;
+
+ err = err ? : mv88e6xxx_g1_read(chip, MV88E6352_G1_VTU_SID,
+ &entry->sid);
+ err = err ? : mv88e6xxx_g1_read(chip, MV88E6XXX_G1_VTU_VID,
+ &entry->vid);
+ err = err ? : mv88e6xxx_g1_read(chip, MV88E6XXX_G1_VTU_DATA1,
+ &entry->data[0]);
+ err = err ? : mv88e6xxx_g1_read(chip, MV88E6XXX_G1_VTU_DATA2,
+ &entry->data[1]);
+ err = err ? : mv88e6xxx_g1_read(chip, MV88E6XXX_G1_VTU_DATA3,
+ &entry->data[2]);
+ if (err)
+ break;
+
+ entry++;
+ } while (stu.sid < mv88e6xxx_max_sid(chip));
+
+ mv88e6xxx_reg_unlock(chip);
+
+ if (err) {
+ kfree(table);
+ return err;
+ }
+
+ *data = (u8 *)table;
+ return 0;
+}
+
static int mv88e6xxx_region_pvt_snapshot(struct devlink *dl,
const struct devlink_region_ops *ops,
struct netlink_ext_ack *extack,
@@ -605,6 +684,12 @@ static struct devlink_region_ops mv88e6xxx_region_vtu_ops = {
.destructor = kfree,
};

+static struct devlink_region_ops mv88e6xxx_region_stu_ops = {
+ .name = "stu",
+ .snapshot = mv88e6xxx_region_stu_snapshot,
+ .destructor = kfree,
+};
+
static struct devlink_region_ops mv88e6xxx_region_pvt_ops = {
.name = "pvt",
.snapshot = mv88e6xxx_region_pvt_snapshot,
@@ -640,6 +725,11 @@ static struct mv88e6xxx_region mv88e6xxx_regions[] = {
.ops = &mv88e6xxx_region_vtu_ops
/* calculated at runtime */
},
+ [MV88E6XXX_REGION_STU] = {
+ .ops = &mv88e6xxx_region_stu_ops,
+ .cond = mv88e6xxx_has_stu,
+ /* calculated at runtime */
+ },
[MV88E6XXX_REGION_PVT] = {
.ops = &mv88e6xxx_region_pvt_ops,
.size = MV88E6XXX_MAX_PVT_ENTRIES * sizeof(u16),
@@ -706,6 +796,10 @@ int mv88e6xxx_setup_devlink_regions_global(struct dsa_switch *ds)
size = (mv88e6xxx_max_vid(chip) + 1) *
sizeof(struct mv88e6xxx_devlink_vtu_entry);
break;
+ case MV88E6XXX_REGION_STU:
+ size = (mv88e6xxx_max_sid(chip) + 1) *
+ sizeof(struct mv88e6xxx_devlink_stu_entry);
+ break;
}

region = dsa_devlink_region_create(ds, ops, 1, size);
--
2.25.1