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b6ef86e9 UB |
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> | |
390dde08 | 15 | #include <asm/ebcdic.h> |
b6ef86e9 | 16 | |
41c80be2 UB |
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 | ||
b6ef86e9 UB |
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); | |
390dde08 | 52 | EBCASC(pnetids, PNETIDS_LEN); |
b6ef86e9 UB |
53 | kfree(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)); | |
390dde08 | 60 | EBCASC(pnetids, sizeof(zdev->util_str)); |
b6ef86e9 UB |
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, (u8 *)pnetids) && | |
81 | memcmp(pnetids[port], 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"); |