path: root/drivers/net/dsa/sja1105/sja1105_tas.h
diff options
authorVladimir Oltean <olteanv@gmail.com>2019-09-15 05:00:02 +0300
committerDavid S. Miller <davem@davemloft.net>2019-09-16 21:32:58 +0200
commit317ab5b86c8e15015efa208ec697affb9bd0b3f2 (patch)
tree49fd5d6980ad7290b38154205b7ee68770fa4be9 /drivers/net/dsa/sja1105/sja1105_tas.h
parentnet: dsa: sja1105: Advertise the 8 TX queues (diff)
net: dsa: sja1105: Configure the Time-Aware Scheduler via tc-taprio offload
This qdisc offload is the closest thing to what the SJA1105 supports in hardware for time-based egress shaping. The switch core really is built around SAE AS6802/TTEthernet (a TTTech standard) but can be made to operate similarly to IEEE 802.1Qbv with some constraints: - The gate control list is a global list for all ports. There are 8 execution threads that iterate through this global list in parallel. I don't know why 8, there are only 4 front-panel ports. - Care must be taken by the user to make sure that two execution threads never get to execute a GCL entry simultaneously. I created a O(n^4) checker for this hardware limitation, prior to accepting a taprio offload configuration as valid. - The spec says that if a GCL entry's interval is shorter than the frame length, you shouldn't send it (and end up in head-of-line blocking). Well, this switch does anyway. - The switch has no concept of ADMIN and OPER configurations. Because it's so simple, the TAS settings are loaded through the static config tables interface, so there isn't even place for any discussion about 'graceful switchover between ADMIN and OPER'. You just reset the switch and upload a new OPER config. - The switch accepts multiple time sources for the gate events. Right now I am using the standalone clock source as opposed to PTP. So the base time parameter doesn't really do much. Support for the PTP clock source will be added in a future series. Signed-off-by: Vladimir Oltean <olteanv@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/dsa/sja1105/sja1105_tas.h')
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/net/dsa/sja1105/sja1105_tas.h b/drivers/net/dsa/sja1105/sja1105_tas.h
new file mode 100644
index 000000000000..0b803c30e640
--- /dev/null
+++ b/drivers/net/dsa/sja1105/sja1105_tas.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0
+ * Copyright (c) 2019, Vladimir Oltean <olteanv@gmail.com>
+ */
+#ifndef _SJA1105_TAS_H
+#define _SJA1105_TAS_H
+#include <net/pkt_sched.h>
+struct sja1105_tas_data {
+ struct tc_taprio_qopt_offload *offload[SJA1105_NUM_PORTS];
+int sja1105_setup_tc_taprio(struct dsa_switch *ds, int port,
+ struct tc_taprio_qopt_offload *admin);
+void sja1105_tas_setup(struct dsa_switch *ds);
+void sja1105_tas_teardown(struct dsa_switch *ds);
+/* C doesn't allow empty structures, bah! */
+struct sja1105_tas_data {
+ u8 dummy;
+static inline int sja1105_setup_tc_taprio(struct dsa_switch *ds, int port,
+ struct tc_taprio_qopt_offload *admin)
+ return -EOPNOTSUPP;
+static inline void sja1105_tas_setup(struct dsa_switch *ds) { }
+static inline void sja1105_tas_teardown(struct dsa_switch *ds) { }
+#endif /* _SJA1105_TAS_H */