2 # SPDX-License-Identifier: BSD-3-Clause
3 # Copyright(c) 2020 Intel Corporation
6 Configure an entire Intel DSA instance, using idxd kernel driver, for DPDK use
16 "Used to read/write paths in a sysfs directory"
17 def __init__(self, path):
20 def read_int(self, filename):
21 "Return a value from sysfs file"
22 with open(os.path.join(self.path, filename)) as f:
23 return int(f.readline())
25 def write_values(self, values):
26 "write dictionary, where key is filename and value is value to write"
27 for filename, contents in values.items():
28 with open(os.path.join(self.path, filename), "w") as f:
29 f.write(str(contents))
33 "Search for the sysfs directory of the PCI device"
34 base_dir = '/sys/bus/pci/devices/'
35 for path, dirs, files in os.walk(base_dir):
38 return os.path.join(base_dir, dir)
39 sys.exit(f"Could not find sysfs directory for device {pci}")
43 "Get the DSA instance ID using the PCI address of the device"
44 pci_dir = get_pci_dir(pci)
45 for path, dirs, files in os.walk(pci_dir):
47 if dir.startswith('dsa') and 'wq' not in dir:
49 sys.exit(f"Could not get device ID for device {pci}")
52 def configure_dsa(dsa_id, queues, prefix):
53 "Configure the DSA instance with appropriate number of queues"
54 dsa_dir = SysfsDir(f"/sys/bus/dsa/devices/dsa{dsa_id}")
55 drv_dir = SysfsDir("/sys/bus/dsa/drivers/dsa")
57 max_groups = dsa_dir.read_int("max_groups")
58 max_engines = dsa_dir.read_int("max_engines")
59 max_queues = dsa_dir.read_int("max_work_queues")
60 max_tokens = dsa_dir.read_int("max_tokens")
62 nb_queues = min(queues, max_queues)
63 if queues > nb_queues:
64 print(f"Setting number of queues to max supported value: {max_queues}")
66 # we want one engine per group, and no more engines than queues
67 nb_groups = min(max_engines, max_groups, nb_queues)
68 for grp in range(nb_groups):
69 dsa_dir.write_values({f"engine{dsa_id}.{grp}/group_id": grp})
71 # configure each queue
72 for q in range(nb_queues):
73 wq_dir = SysfsDir(os.path.join(dsa_dir.path, f"wq{dsa_id}.{q}"))
74 wq_dir.write_values({"group_id": q % nb_groups,
77 "name": f"{prefix}_wq{dsa_id}.{q}",
79 "size": int(max_tokens / nb_queues)})
81 # enable device and then queues
82 drv_dir.write_values({"bind": f"dsa{dsa_id}"})
83 for q in range(nb_queues):
84 drv_dir.write_values({"bind": f"wq{dsa_id}.{q}"})
88 "Main function, does arg parsing and calls config function"
89 arg_p = argparse.ArgumentParser(
90 description="Configure whole DSA device instance for DPDK use")
91 arg_p.add_argument('dsa_id',
92 help="Specify DSA instance either via DSA instance number or PCI address")
93 arg_p.add_argument('-q', metavar='queues', type=int, default=255,
94 help="Number of queues to set up")
95 arg_p.add_argument('--name-prefix', metavar='prefix', dest='prefix',
97 help="Prefix for workqueue name to mark for DPDK use [default: 'dpdk']")
98 parsed_args = arg_p.parse_args(args[1:])
100 dsa_id = parsed_args.dsa_id
101 dsa_id = get_dsa_id(dsa_id) if ':' in dsa_id else dsa_id
102 configure_dsa(dsa_id, parsed_args.q, parsed_args.prefix)
105 if __name__ == "__main__":