1 files changed, 167 insertions, 0 deletions
diff --git a/tools/testing/selftests/drivers/net/ring_reconfig.py b/tools/testing/selftests/drivers/net/ring_reconfig.py
new file mode 100755
index 000000000000..f9530a8b0856
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/ring_reconfig.py
@@ -0,0 +1,167 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+
+"""
+Test channel and ring size configuration via ethtool (-L / -G).
+"""
+
+from lib.py import ksft_run, ksft_exit, ksft_pr
+from lib.py import ksft_eq
+from lib.py import NetDrvEpEnv, EthtoolFamily, GenerateTraffic
+from lib.py import defer, NlError
+
+
+def channels(cfg) -> None:
+    """
+    Twiddle channel counts in various combinations of parameters.
+    We're only looking for driver adhering to the requested config
+    if the config is accepted and crashes.
+    """
+    ehdr = {'header':{'dev-index': cfg.ifindex}}
+    chans = cfg.eth.channels_get(ehdr)
+
+    all_keys = ["rx", "tx", "combined"]
+    mixes = [{"combined"}, {"rx", "tx"}, {"rx", "combined"}, {"tx", "combined"},
+             {"rx", "tx", "combined"},]
+
+    # Get the set of keys that device actually supports
+    restore = {}
+    supported = set()
+    for key in all_keys:
+        if key + "-max" in chans:
+            supported.add(key)
+            restore |= {key + "-count": chans[key + "-count"]}
+
+    defer(cfg.eth.channels_set, ehdr | restore)
+
+    def test_config(config):
+        try:
+            cfg.eth.channels_set(ehdr | config)
+            get = cfg.eth.channels_get(ehdr)
+            for k, v in config.items():
+                ksft_eq(get.get(k, 0), v)
+        except NlError as e:
+            failed.append(mix)
+            ksft_pr("Can't set", config, e)
+        else:
+            ksft_pr("Okay", config)
+
+    failed = []
+    for mix in mixes:
+        if not mix.issubset(supported):
+            continue
+
+        # Set all the values in the mix to 1, other supported to 0
+        config = {}
+        for key in all_keys:
+            config[key + "-count"] = 1 if key in mix else 0
+        test_config(config)
+
+    for mix in mixes:
+        if not mix.issubset(supported):
+            continue
+        if mix in failed:
+            continue
+
+        # Set all the values in the mix to max, other supported to 0
+        config = {}
+        for key in all_keys:
+            config[key + "-count"] = chans[key + '-max'] if key in mix else 0
+        test_config(config)
+
+
+def _configure_min_ring_cnt(cfg) -> None:
+    """ Try to configure a single Rx/Tx ring. """
+    ehdr = {'header':{'dev-index': cfg.ifindex}}
+    chans = cfg.eth.channels_get(ehdr)
+
+    all_keys = ["rx-count", "tx-count", "combined-count"]
+    restore = {}
+    config = {}
+    for key in all_keys:
+        if key in chans:
+            restore[key] = chans[key]
+            config[key] = 0
+
+    if chans.get('combined-count', 0) > 1:
+        config['combined-count'] = 1
+    elif chans.get('rx-count', 0) > 1 and chans.get('tx-count', 0) > 1:
+        config['tx-count'] = 1
+        config['rx-count'] = 1
+    else:
+        # looks like we're already on 1 channel
+        return
+
+    cfg.eth.channels_set(ehdr | config)
+    defer(cfg.eth.channels_set, ehdr | restore)
+
+
+def ringparam(cfg) -> None:
+    """
+    Tweak the ringparam configuration. Try to run some traffic over min
+    ring size to make sure it actually functions.
+    """
+    ehdr = {'header':{'dev-index': cfg.ifindex}}
+    rings = cfg.eth.rings_get(ehdr)
+
+    restore = {}
+    maxes = {}
+    params = set()
+    for key in rings.keys():
+        if 'max' in key:
+            param = key[:-4]
+            maxes[param] = rings[key]
+            params.add(param)
+            restore[param] = rings[param]
+
+    defer(cfg.eth.rings_set, ehdr | restore)
+
+    # Speed up the reconfig by configuring just one ring
+    _configure_min_ring_cnt(cfg)
+
+    # Try to reach min on all settings
+    for param in params:
+        val = rings[param]
+        while True:
+            try:
+                cfg.eth.rings_set({'header':{'dev-index': cfg.ifindex},
+                                   param: val // 2})
+                if val == 0:
+                    break
+                val //= 2
+            except NlError:
+                break
+
+        get = cfg.eth.rings_get(ehdr)
+        ksft_eq(get[param], val)
+
+        ksft_pr(f"Reached min for '{param}' at {val} (max {rings[param]})")
+
+    GenerateTraffic(cfg).wait_pkts_and_stop(10000)
+
+    # Try max across all params, if the driver supports large rings
+    # this may OOM so we ignore errors
+    try:
+        ksft_pr("Applying max settings")
+        config = {p: maxes[p] for p in params}
+        cfg.eth.rings_set(ehdr | config)
+    except NlError as e:
+        ksft_pr("Can't set max params", config, e)
+    else:
+        GenerateTraffic(cfg).wait_pkts_and_stop(10000)
+
+
+def main() -> None:
+    """ Ksft boiler plate main """
+
+    with NetDrvEpEnv(__file__) as cfg:
+        cfg.eth = EthtoolFamily()
+
+        ksft_run([channels,
+                  ringparam],
+                 args=(cfg, ))
+    ksft_exit()
+
+
+if __name__ == "__main__":
+    main()