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	Pnetids are retrieved from the underlying hardware as EBCDIC. This patch converts pnetids to ASCII. Signed-off-by: Hans Wippel <hwippel@linux.ibm.com> Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
		
			
				
	
	
		
			91 lines
		
	
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			91 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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