1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * IBM System z PNET ID Support
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright IBM Corp. 2018
6*4882a593Smuzhiyun */
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun #include <linux/device.h>
9*4882a593Smuzhiyun #include <linux/module.h>
10*4882a593Smuzhiyun #include <linux/pci.h>
11*4882a593Smuzhiyun #include <linux/types.h>
12*4882a593Smuzhiyun #include <asm/ccwgroup.h>
13*4882a593Smuzhiyun #include <asm/ccwdev.h>
14*4882a593Smuzhiyun #include <asm/pnet.h>
15*4882a593Smuzhiyun #include <asm/ebcdic.h>
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun #define PNETIDS_LEN 64 /* Total utility string length in bytes
18*4882a593Smuzhiyun * to cover up to 4 PNETIDs of 16 bytes
19*4882a593Smuzhiyun * for up to 4 device ports
20*4882a593Smuzhiyun */
21*4882a593Smuzhiyun #define MAX_PNETID_LEN 16 /* Max.length of a single port PNETID */
22*4882a593Smuzhiyun #define MAX_PNETID_PORTS (PNETIDS_LEN / MAX_PNETID_LEN)
23*4882a593Smuzhiyun /* Max. # of ports with a PNETID */
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun /*
26*4882a593Smuzhiyun * Get the PNETIDs from a device.
27*4882a593Smuzhiyun * s390 hardware supports the definition of a so-called Physical Network
28*4882a593Smuzhiyun * Identifier (short PNETID) per network device port. These PNETIDs can be
29*4882a593Smuzhiyun * used to identify network devices that are attached to the same physical
30*4882a593Smuzhiyun * network (broadcast domain).
31*4882a593Smuzhiyun *
32*4882a593Smuzhiyun * The device can be
33*4882a593Smuzhiyun * - a ccwgroup device with all bundled subchannels having the same PNETID
34*4882a593Smuzhiyun * - a PCI attached network device
35*4882a593Smuzhiyun *
36*4882a593Smuzhiyun * Returns:
37*4882a593Smuzhiyun * 0: PNETIDs extracted from device.
38*4882a593Smuzhiyun * -ENOMEM: No memory to extract utility string.
39*4882a593Smuzhiyun * -EOPNOTSUPP: Device type without utility string support
40*4882a593Smuzhiyun */
pnet_ids_by_device(struct device * dev,u8 * pnetids)41*4882a593Smuzhiyun static int pnet_ids_by_device(struct device *dev, u8 *pnetids)
42*4882a593Smuzhiyun {
43*4882a593Smuzhiyun memset(pnetids, 0, PNETIDS_LEN);
44*4882a593Smuzhiyun if (dev_is_ccwgroup(dev)) {
45*4882a593Smuzhiyun struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
46*4882a593Smuzhiyun u8 *util_str;
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun util_str = ccw_device_get_util_str(gdev->cdev[0], 0);
49*4882a593Smuzhiyun if (!util_str)
50*4882a593Smuzhiyun return -ENOMEM;
51*4882a593Smuzhiyun memcpy(pnetids, util_str, PNETIDS_LEN);
52*4882a593Smuzhiyun EBCASC(pnetids, PNETIDS_LEN);
53*4882a593Smuzhiyun kfree(util_str);
54*4882a593Smuzhiyun return 0;
55*4882a593Smuzhiyun }
56*4882a593Smuzhiyun if (dev_is_pci(dev)) {
57*4882a593Smuzhiyun struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
58*4882a593Smuzhiyun
59*4882a593Smuzhiyun memcpy(pnetids, zdev->util_str, sizeof(zdev->util_str));
60*4882a593Smuzhiyun EBCASC(pnetids, sizeof(zdev->util_str));
61*4882a593Smuzhiyun return 0;
62*4882a593Smuzhiyun }
63*4882a593Smuzhiyun return -EOPNOTSUPP;
64*4882a593Smuzhiyun }
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun /*
67*4882a593Smuzhiyun * Extract the pnetid for a device port.
68*4882a593Smuzhiyun *
69*4882a593Smuzhiyun * Return 0 if a pnetid is found and -ENOENT otherwise.
70*4882a593Smuzhiyun */
pnet_id_by_dev_port(struct device * dev,unsigned short port,u8 * pnetid)71*4882a593Smuzhiyun int pnet_id_by_dev_port(struct device *dev, unsigned short port, u8 *pnetid)
72*4882a593Smuzhiyun {
73*4882a593Smuzhiyun u8 pnetids[MAX_PNETID_PORTS][MAX_PNETID_LEN];
74*4882a593Smuzhiyun static const u8 zero[MAX_PNETID_LEN] = { 0 };
75*4882a593Smuzhiyun int rc = 0;
76*4882a593Smuzhiyun
77*4882a593Smuzhiyun if (!dev || port >= MAX_PNETID_PORTS)
78*4882a593Smuzhiyun return -ENOENT;
79*4882a593Smuzhiyun
80*4882a593Smuzhiyun if (!pnet_ids_by_device(dev, (u8 *)pnetids) &&
81*4882a593Smuzhiyun memcmp(pnetids[port], zero, MAX_PNETID_LEN))
82*4882a593Smuzhiyun memcpy(pnetid, pnetids[port], MAX_PNETID_LEN);
83*4882a593Smuzhiyun else
84*4882a593Smuzhiyun rc = -ENOENT;
85*4882a593Smuzhiyun
86*4882a593Smuzhiyun return rc;
87*4882a593Smuzhiyun }
88*4882a593Smuzhiyun EXPORT_SYMBOL_GPL(pnet_id_by_dev_port);
89*4882a593Smuzhiyun
90*4882a593Smuzhiyun MODULE_DESCRIPTION("pnetid determination from utility strings");
91*4882a593Smuzhiyun MODULE_LICENSE("GPL");
92