92 lines
2.4 KiB
C
92 lines
2.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* IBM System z PNET ID Support
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*
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* Copyright IBM Corp. 2018
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*/
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#include <linux/device.h>
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#include <linux/module.h>
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#include <linux/pci.h>
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#include <linux/types.h>
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#include <asm/ccwgroup.h>
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#include <asm/ccwdev.h>
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#include <asm/pnet.h>
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#include <asm/ebcdic.h>
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#define PNETIDS_LEN 64 /* Total utility string length in bytes
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* to cover up to 4 PNETIDs of 16 bytes
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* for up to 4 device ports
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*/
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#define MAX_PNETID_LEN 16 /* Max.length of a single port PNETID */
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#define MAX_PNETID_PORTS (PNETIDS_LEN / MAX_PNETID_LEN)
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/* Max. # of ports with a PNETID */
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/*
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* Get the PNETIDs from a device.
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* s390 hardware supports the definition of a so-called Physical Network
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* Identifier (short PNETID) per network device port. These PNETIDs can be
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* used to identify network devices that are attached to the same physical
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* network (broadcast domain).
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*
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* The device can be
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* - a ccwgroup device with all bundled subchannels having the same PNETID
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* - a PCI attached network device
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*
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* Returns:
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* 0: PNETIDs extracted from device.
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* -ENOMEM: No memory to extract utility string.
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* -EOPNOTSUPP: Device type without utility string support
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*/
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static int pnet_ids_by_device(struct device *dev, u8 *pnetids)
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{
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memset(pnetids, 0, PNETIDS_LEN);
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if (dev_is_ccwgroup(dev)) {
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struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
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u8 *util_str;
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util_str = ccw_device_get_util_str(gdev->cdev[0], 0);
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if (!util_str)
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return -ENOMEM;
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memcpy(pnetids, util_str, PNETIDS_LEN);
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EBCASC(pnetids, PNETIDS_LEN);
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kfree(util_str);
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return 0;
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}
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if (dev_is_pci(dev)) {
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struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
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memcpy(pnetids, zdev->util_str, sizeof(zdev->util_str));
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EBCASC(pnetids, sizeof(zdev->util_str));
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return 0;
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}
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return -EOPNOTSUPP;
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}
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/*
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* Extract the pnetid for a device port.
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*
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* Return 0 if a pnetid is found and -ENOENT otherwise.
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*/
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int pnet_id_by_dev_port(struct device *dev, unsigned short port, u8 *pnetid)
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{
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u8 pnetids[MAX_PNETID_PORTS][MAX_PNETID_LEN];
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static const u8 zero[MAX_PNETID_LEN] = { 0 };
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int rc = 0;
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if (!dev || port >= MAX_PNETID_PORTS)
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return -ENOENT;
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if (!pnet_ids_by_device(dev, (u8 *)pnetids) &&
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memcmp(pnetids[port], zero, MAX_PNETID_LEN))
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memcpy(pnetid, pnetids[port], MAX_PNETID_LEN);
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else
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rc = -ENOENT;
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return rc;
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}
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EXPORT_SYMBOL_GPL(pnet_id_by_dev_port);
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MODULE_DESCRIPTION("pnetid determination from utility strings");
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MODULE_LICENSE("GPL");
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