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