| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame^] | 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 | |
| 16 | /* |
| 17 | * Get the PNETIDs from a device. |
| 18 | * s390 hardware supports the definition of a so-called Physical Network |
| 19 | * Identifier (short PNETID) per network device port. These PNETIDs can be |
| 20 | * used to identify network devices that are attached to the same physical |
| 21 | * network (broadcast domain). |
| 22 | * |
| 23 | * The device can be |
| 24 | * - a ccwgroup device with all bundled subchannels having the same PNETID |
| 25 | * - a PCI attached network device |
| 26 | * |
| 27 | * Returns: |
| 28 | * 0: PNETIDs extracted from device. |
| 29 | * -ENOMEM: No memory to extract utility string. |
| 30 | * -EOPNOTSUPP: Device type without utility string support |
| 31 | */ |
| 32 | static int pnet_ids_by_device(struct device *dev, u8 *pnetids) |
| 33 | { |
| 34 | memset(pnetids, 0, PNETIDS_LEN); |
| 35 | if (dev_is_ccwgroup(dev)) { |
| 36 | struct ccwgroup_device *gdev = to_ccwgroupdev(dev); |
| 37 | u8 *util_str; |
| 38 | |
| 39 | util_str = ccw_device_get_util_str(gdev->cdev[0], 0); |
| 40 | if (!util_str) |
| 41 | return -ENOMEM; |
| 42 | memcpy(pnetids, util_str, PNETIDS_LEN); |
| 43 | kfree(util_str); |
| 44 | return 0; |
| 45 | } |
| 46 | if (dev_is_pci(dev)) { |
| 47 | struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); |
| 48 | |
| 49 | memcpy(pnetids, zdev->util_str, sizeof(zdev->util_str)); |
| 50 | return 0; |
| 51 | } |
| 52 | return -EOPNOTSUPP; |
| 53 | } |
| 54 | |
| 55 | /* |
| 56 | * Extract the pnetid for a device port. |
| 57 | * |
| 58 | * Return 0 if a pnetid is found and -ENOENT otherwise. |
| 59 | */ |
| 60 | int pnet_id_by_dev_port(struct device *dev, unsigned short port, u8 *pnetid) |
| 61 | { |
| 62 | u8 pnetids[MAX_PNETID_PORTS][MAX_PNETID_LEN]; |
| 63 | static const u8 zero[MAX_PNETID_LEN] = { 0 }; |
| 64 | int rc = 0; |
| 65 | |
| 66 | if (!dev || port >= MAX_PNETID_PORTS) |
| 67 | return -ENOENT; |
| 68 | |
| 69 | if (!pnet_ids_by_device(dev, (u8 *)pnetids) && |
| 70 | memcmp(pnetids[port], zero, MAX_PNETID_LEN)) |
| 71 | memcpy(pnetid, pnetids[port], MAX_PNETID_LEN); |
| 72 | else |
| 73 | rc = -ENOENT; |
| 74 | |
| 75 | return rc; |
| 76 | } |
| 77 | EXPORT_SYMBOL_GPL(pnet_id_by_dev_port); |
| 78 | |
| 79 | MODULE_DESCRIPTION("pnetid determination from utility strings"); |
| 80 | MODULE_LICENSE("GPL"); |