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/pci.h> 10 #include <linux/types.h> 11 #include <asm/ccwgroup.h> 12 #include <asm/ccwdev.h> 13 #include <asm/pnet.h> 14 15 /* 16 * Get the PNETIDs from a device. 17 * s390 hardware supports the definition of a so-called Physical Network 18 * Identifier (short PNETID) per network device port. These PNETIDs can be 19 * used to identify network devices that are attached to the same physical 20 * network (broadcast domain). 21 * 22 * The device can be 23 * - a ccwgroup device with all bundled subchannels having the same PNETID 24 * - a PCI attached network device 25 * 26 * Returns: 27 * 0: PNETIDs extracted from device. 28 * -ENOMEM: No memory to extract utility string. 29 * -EOPNOTSUPP: Device type without utility string support 30 */ 31 static int pnet_ids_by_device(struct device *dev, u8 *pnetids) 32 { 33 memset(pnetids, 0, PNETIDS_LEN); 34 if (dev_is_ccwgroup(dev)) { 35 struct ccwgroup_device *gdev = to_ccwgroupdev(dev); 36 u8 *util_str; 37 38 util_str = ccw_device_get_util_str(gdev->cdev[0], 0); 39 if (!util_str) 40 return -ENOMEM; 41 memcpy(pnetids, util_str, PNETIDS_LEN); 42 kfree(util_str); 43 return 0; 44 } 45 if (dev_is_pci(dev)) { 46 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); 47 48 memcpy(pnetids, zdev->util_str, sizeof(zdev->util_str)); 49 return 0; 50 } 51 return -EOPNOTSUPP; 52 } 53 54 /* 55 * Extract the pnetid for a device port. 56 * 57 * Return 0 if a pnetid is found and -ENOENT otherwise. 58 */ 59 int pnet_id_by_dev_port(struct device *dev, unsigned short port, u8 *pnetid) 60 { 61 u8 pnetids[MAX_PNETID_PORTS][MAX_PNETID_LEN]; 62 static const u8 zero[MAX_PNETID_LEN] = { 0 }; 63 int rc = 0; 64 65 if (!dev || port >= MAX_PNETID_PORTS) 66 return -ENOENT; 67 68 if (!pnet_ids_by_device(dev, (u8 *)pnetids) && 69 memcmp(pnetids[port], zero, MAX_PNETID_LEN)) 70 memcpy(pnetid, pnetids[port], MAX_PNETID_LEN); 71 else 72 rc = -ENOENT; 73 74 return rc; 75 } 76 EXPORT_SYMBOL_GPL(pnet_id_by_dev_port); 77