1#!/usr/bin/env python3
  2# SPDX-License-Identifier: GPL-2.0
  3
  4from subprocess import PIPE, Popen
  5import json
  6import time
  7import argparse
  8import collections
  9import sys
 10
 11#
 12# Test port split configuration using devlink-port lanes attribute.
 13# The test is skipped in case the attribute is not available.
 14#
 15# First, check that all the ports with 1 lane fail to split.
 16# Second, check that all the ports with more than 1 lane can be split
 17# to all valid configurations (e.g., split to 2, split to 4 etc.)
 18#
 19
 20
 21# Kselftest framework requirement - SKIP code is 4
 22KSFT_SKIP=4
 23Port = collections.namedtuple('Port', 'bus_info name')
 24
 25
 26def run_command(cmd, should_fail=False):
 27    """
 28    Run a command in subprocess.
 29    Return: Tuple of (stdout, stderr).
 30    """
 31
 32    p = Popen(cmd, stdout=PIPE, stderr=PIPE, shell=True)
 33    stdout, stderr = p.communicate()
 34    stdout, stderr = stdout.decode(), stderr.decode()
 35
 36    if stderr != "" and not should_fail:
 37        print("Error sending command: %s" % cmd)
 38        print(stdout)
 39        print(stderr)
 40    return stdout, stderr
 41
 42
 43class devlink_ports(object):
 44    """
 45    Class that holds information on the devlink ports, required to the tests;
 46    if_names: A list of interfaces in the devlink ports.
 47    """
 48
 49    def get_if_names(dev):
 50        """
 51        Get a list of physical devlink ports.
 52        Return: Array of tuples (bus_info/port, if_name).
 53        """
 54
 55        arr = []
 56
 57        cmd = "devlink -j port show"
 58        stdout, stderr = run_command(cmd)
 59        assert stderr == ""
 60        ports = json.loads(stdout)['port']
 61
 62        for port in ports:
 63            if dev in port:
 64                if ports[port]['flavour'] == 'physical':
 65                    arr.append(Port(bus_info=port, name=ports[port]['netdev']))
 66
 67        return arr
 68
 69    def __init__(self, dev):
 70        self.if_names = devlink_ports.get_if_names(dev)
 71
 72
 73def get_max_lanes(port):
 74    """
 75    Get the $port's maximum number of lanes.
 76    Return: number of lanes, e.g. 1, 2, 4 and 8.
 77    """
 78
 79    cmd = "devlink -j port show %s" % port
 80    stdout, stderr = run_command(cmd)
 81    assert stderr == ""
 82    values = list(json.loads(stdout)['port'].values())[0]
 83
 84    if 'lanes' in values:
 85        lanes = values['lanes']
 86    else:
 87        lanes = 0
 88    return lanes
 89
 90
 91def get_split_ability(port):
 92    """
 93    Get the $port split ability.
 94    Return: split ability, true or false.
 95    """
 96
 97    cmd = "devlink -j port show %s" % port.name
 98    stdout, stderr = run_command(cmd)
 99    assert stderr == ""
100    values = list(json.loads(stdout)['port'].values())[0]
101
102    return values['splittable']
103
104
105def split(k, port, should_fail=False):
106    """
107    Split $port into $k ports.
108    If should_fail == True, the split should fail. Otherwise, should pass.
109    Return: Array of sub ports after splitting.
110            If the $port wasn't split, the array will be empty.
111    """
112
113    cmd = "devlink port split %s count %s" % (port.bus_info, k)
114    stdout, stderr = run_command(cmd, should_fail=should_fail)
115
116    if should_fail:
117        if not test(stderr != "", "%s is unsplittable" % port.name):
118            print("split an unsplittable port %s" % port.name)
119            return create_split_group(port, k)
120    else:
121        if stderr == "":
122            return create_split_group(port, k)
123        print("didn't split a splittable port %s" % port.name)
124
125    return []
126
127
128def unsplit(port):
129    """
130    Unsplit $port.
131    """
132
133    cmd = "devlink port unsplit %s" % port
134    stdout, stderr = run_command(cmd)
135    test(stderr == "", "Unsplit port %s" % port)
136
137
138def exists(port, dev):
139    """
140    Check if $port exists in the devlink ports.
141    Return: True is so, False otherwise.
142    """
143
144    return any(dev_port.name == port
145               for dev_port in devlink_ports.get_if_names(dev))
146
147
148def exists_and_lanes(ports, lanes, dev):
149    """
150    Check if every port in the list $ports exists in the devlink ports and has
151    $lanes number of lanes after splitting.
152    Return: True if both are True, False otherwise.
153    """
154
155    for port in ports:
156        max_lanes = get_max_lanes(port)
157        if not exists(port, dev):
158            print("port %s doesn't exist in devlink ports" % port)
159            return False
160        if max_lanes != lanes:
161            print("port %s has %d lanes, but %s were expected"
162                  % (port, lanes, max_lanes))
163            return False
164    return True
165
166
167def test(cond, msg):
168    """
169    Check $cond and print a message accordingly.
170    Return: True is pass, False otherwise.
171    """
172
173    if cond:
174        print("TEST: %-60s [ OK ]" % msg)
175    else:
176        print("TEST: %-60s [FAIL]" % msg)
177
178    return cond
179
180
181def create_split_group(port, k):
182    """
183    Create the split group for $port.
184    Return: Array with $k elements, which are the split port group.
185    """
186
187    return list(port.name + "s" + str(i) for i in range(k))
188
189
190def split_unsplittable_port(port, k):
191    """
192    Test that splitting of unsplittable port fails.
193    """
194
195    # split to max
196    new_split_group = split(k, port, should_fail=True)
197
198    if new_split_group != []:
199        unsplit(port.bus_info)
200
201
202def split_splittable_port(port, k, lanes, dev):
203    """
204    Test that splitting of splittable port passes correctly.
205    """
206
207    new_split_group = split(k, port)
208
209    # Once the split command ends, it takes some time to the sub ifaces'
210    # to get their names. Use udevadm to continue only when all current udev
211    # events are handled.
212    cmd = "udevadm settle"
213    stdout, stderr = run_command(cmd)
214    assert stderr == ""
215
216    if new_split_group != []:
217        test(exists_and_lanes(new_split_group, lanes/k, dev),
218             "split port %s into %s" % (port.name, k))
219
220    unsplit(port.bus_info)
221
222
223def make_parser():
224    parser = argparse.ArgumentParser(description='A test for port splitting.')
225    parser.add_argument('--dev',
226                        help='The devlink handle of the device under test. ' +
227                             'The default is the first registered devlink ' +
228                             'handle.')
229
230    return parser
231
232
233def main(cmdline=None):
234    parser = make_parser()
235    args = parser.parse_args(cmdline)
236
237    dev = args.dev
238    if not dev:
239        cmd = "devlink -j dev show"
240        stdout, stderr = run_command(cmd)
241        assert stderr == ""
242
243        devs = json.loads(stdout)['dev']
244        if devs:
245            dev = list(devs.keys())[0]
246        else:
247            print("no devlink device was found, test skipped")
248            sys.exit(KSFT_SKIP)
249
250    cmd = "devlink dev show %s" % dev
251    stdout, stderr = run_command(cmd)
252    if stderr != "":
253        print("devlink device %s can not be found" % dev)
254        sys.exit(1)
255
256    ports = devlink_ports(dev)
257
258    for port in ports.if_names:
259        max_lanes = get_max_lanes(port.name)
260
261        # If max lanes is 0, do not test port splitting at all
262        if max_lanes == 0:
263            continue
264
265        # If 1 lane, shouldn't be able to split
266        elif max_lanes == 1:
267            test(not get_split_ability(port),
268                 "%s should not be able to split" % port.name)
269            split_unsplittable_port(port, max_lanes)
270
271        # Else, splitting should pass and all the split ports should exist.
272        else:
273            lane = max_lanes
274            test(get_split_ability(port),
275                 "%s should be able to split" % port.name)
276            while lane > 1:
277                split_splittable_port(port, lane, max_lanes, dev)
278
279                lane //= 2
280
281
282if __name__ == "__main__":
283    main()