diff mbox series

[net-next,2/6] net: dsa: hellcreek: Report META data usage

Message ID 20210311175344.3084-3-kurt@kmk-computers.de
State New
Headers show
Series net: dsa: hellcreek: Add support for dumping tables | expand

Commit Message

Kurt Kanzenbach March 11, 2021, 5:53 p.m. UTC 
Report the META data descriptor usage via devlink. This is a useful debug
feature. The actual size depends on the used Hellcreek version:

|root@tsn:~# devlink resource show platform/ff240000.switch
|platform/ff240000.switch:
|  name VLAN size 4096 occ 3 unit entry dpipe_tables none
|  name FDB size 256 occ 6 unit entry dpipe_tables none
|  name RAM size 320 occ 14 unit entry dpipe_tables none
|  name META size 320 occ 5 unit entry dpipe_tables none

Signed-off-by: Kurt Kanzenbach <kurt@kmk-computers.de>
---
 drivers/net/dsa/hirschmann/hellcreek.c | 36 ++++++++++++++++++++++++--
 drivers/net/dsa/hirschmann/hellcreek.h |  2 ++
 2 files changed, 36 insertions(+), 2 deletions(-)

Comments

Andrew Lunn March 11, 2021, 10:52 p.m. UTC | #1 
On Thu, Mar 11, 2021 at 06:53:40PM +0100, Kurt Kanzenbach wrote:
> Report the META data descriptor usage via devlink.

Jakubs question is also relevant here. Please could you give a bit
more background about what the meta data is?

Thanks
	Andrew
Kurt Kanzenbach March 12, 2021, 4:11 p.m. UTC | #2 
On Fri Mar 12 2021, Vladimir Oltean wrote:
> On Thu, Mar 11, 2021 at 11:52:41PM +0100, Andrew Lunn wrote:

>> On Thu, Mar 11, 2021 at 06:53:40PM +0100, Kurt Kanzenbach wrote:

>> > Report the META data descriptor usage via devlink.

>> 

>> Jakubs question is also relevant here. Please could you give a bit

>> more background about what the meta data is?

>

> Not having seen any documentation for this device, my guess is that

> metadata descriptors are frame references, and the RAM page count is

> for packet memory buffers. Nonetheless, I would still like to hear it

> from Kurt.


Yes, exactly.

> There is still a lot unknown even if I am correct. For example, if

> the frame references or buffers can be partitioned, or if watermarks for

> things like congestion/flow control can be set, then maybe devlink-sb is

> a better choice (as that has an occupancy facility as well)?

> Fully understand that it is not as trivial as exposing a devlink

> resource, but on Ocelot/Felix I quite appreciate having the feature

> (drivers/net/ethernet/mscc/ocelot_devlink.c). And knowing that this is a

> TSN switch, I expect that sooner or later, the need to have control over

> resource partitioning per traffic class will arise anyway.

>


True. The switch can actually distinguish between critical and
background traffic. Multiple limits can be configured: Maximum memory,
reserved memory for critical traffic, background traffic rates and queue
depths. I'll take a look at devlink-sb for that.

Thanks,
Kurt
diff mbox series

Patch

diff --git a/drivers/net/dsa/hirschmann/hellcreek.c b/drivers/net/dsa/hirschmann/hellcreek.c
index c7a439336336..d3760e2c9d8a 100644
--- a/drivers/net/dsa/hirschmann/hellcreek.c
+++ b/drivers/net/dsa/hirschmann/hellcreek.c
@@ -221,13 +221,15 @@  static void hellcreek_feature_detect(struct hellcreek *hellcreek)
 
 	features = hellcreek_read(hellcreek, HR_FEABITS0);
 
-	/* Detect the FDB table size and the maximum RAM page count. The size
-	 * and current utilization can be queried via devlink.
+	/* Detect the FDB table size and the maximum RAM page and meta data
+	 * count. The size and current utilization can be queried via devlink.
 	 */
 	hellcreek->fdb_entries = ((features & HR_FEABITS0_FDBBINS_MASK) >>
 				  HR_FEABITS0_FDBBINS_SHIFT) * 32;
 	hellcreek->page_count  = ((features & HR_FEABITS0_PCNT_MASK) >>
 				  HR_FEABITS0_PCNT_SHIFT) * 32;
+	hellcreek->meta_count  = ((features & HR_FEABITS0_MCNT_MASK) >>
+				  HR_FEABITS0_MCNT_SHIFT) * 32;
 }
 
 static enum dsa_tag_protocol hellcreek_get_tag_protocol(struct dsa_switch *ds,
@@ -1048,9 +1050,22 @@  static u64 hellcreek_devlink_ram_usage_get(void *priv)
 	return usage;
 }
 
+static u64 hellcreek_devlink_meta_usage_get(void *priv)
+{
+	struct hellcreek *hellcreek = priv;
+	u64 usage = 0;
+
+	/* Indicates how many free meta data descriptors are available. */
+	usage = hellcreek_read(hellcreek, HR_MFREE);
+	usage = hellcreek->meta_count - usage;
+
+	return usage;
+}
+
 static int hellcreek_setup_devlink_resources(struct dsa_switch *ds)
 {
 	struct devlink_resource_size_params size_vlan_params;
+	struct devlink_resource_size_params size_meta_params;
 	struct devlink_resource_size_params size_fdb_params;
 	struct devlink_resource_size_params size_ram_params;
 	struct hellcreek *hellcreek = ds->priv;
@@ -1070,6 +1085,11 @@  static int hellcreek_setup_devlink_resources(struct dsa_switch *ds)
 					  hellcreek->page_count,
 					  1, DEVLINK_RESOURCE_UNIT_ENTRY);
 
+	devlink_resource_size_params_init(&size_meta_params,
+					  hellcreek->meta_count,
+					  hellcreek->meta_count,
+					  1, DEVLINK_RESOURCE_UNIT_ENTRY);
+
 	err = dsa_devlink_resource_register(ds, "VLAN", VLAN_N_VID,
 					    HELLCREEK_DEVLINK_PARAM_ID_VLAN_TABLE,
 					    DEVLINK_RESOURCE_ID_PARENT_TOP,
@@ -1091,6 +1111,13 @@  static int hellcreek_setup_devlink_resources(struct dsa_switch *ds)
 	if (err)
 		goto out;
 
+	err = dsa_devlink_resource_register(ds, "META", hellcreek->meta_count,
+					    HELLCREEK_DEVLINK_PARAM_ID_METADATA_USAGE,
+					    DEVLINK_RESOURCE_ID_PARENT_TOP,
+					    &size_meta_params);
+	if (err)
+		goto out;
+
 	dsa_devlink_resource_occ_get_register(ds,
 					      HELLCREEK_DEVLINK_PARAM_ID_VLAN_TABLE,
 					      hellcreek_devlink_vlan_table_get,
@@ -1106,6 +1133,11 @@  static int hellcreek_setup_devlink_resources(struct dsa_switch *ds)
 					      hellcreek_devlink_ram_usage_get,
 					      hellcreek);
 
+	dsa_devlink_resource_occ_get_register(ds,
+					      HELLCREEK_DEVLINK_PARAM_ID_METADATA_USAGE,
+					      hellcreek_devlink_meta_usage_get,
+					      hellcreek);
+
 	return 0;
 
 out:
diff --git a/drivers/net/dsa/hirschmann/hellcreek.h b/drivers/net/dsa/hirschmann/hellcreek.h
index 9c08aeabbc24..06737caac37e 100644
--- a/drivers/net/dsa/hirschmann/hellcreek.h
+++ b/drivers/net/dsa/hirschmann/hellcreek.h
@@ -287,6 +287,7 @@  struct hellcreek {
 	u16 status_out;		/* ptp.status_out shadow */
 	size_t fdb_entries;
 	size_t page_count;
+	size_t meta_count;
 };
 
 /* A Qbv schedule can only started up to 8 seconds in the future. If the delta
@@ -304,6 +305,7 @@  enum hellcreek_devlink_resource_id {
 	HELLCREEK_DEVLINK_PARAM_ID_VLAN_TABLE,
 	HELLCREEK_DEVLINK_PARAM_ID_FDB_TABLE,
 	HELLCREEK_DEVLINK_PARAM_ID_RAM_USAGE,
+	HELLCREEK_DEVLINK_PARAM_ID_METADATA_USAGE,
 };
 
 #endif /* _HELLCREEK_H_ */