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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/s390/net/pnet.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/s390/net/pnet.c')
-rw-r--r--arch/s390/net/pnet.c91
1 files changed, 91 insertions, 0 deletions
diff --git a/arch/s390/net/pnet.c b/arch/s390/net/pnet.c
new file mode 100644
index 000000000..79211bec0
--- /dev/null
+++ b/arch/s390/net/pnet.c
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * IBM System z PNET ID Support
+ *
+ * Copyright IBM Corp. 2018
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/types.h>
+#include <asm/ccwgroup.h>
+#include <asm/ccwdev.h>
+#include <asm/pnet.h>
+#include <asm/ebcdic.h>
+
+#define PNETIDS_LEN 64 /* Total utility string length in bytes
+ * to cover up to 4 PNETIDs of 16 bytes
+ * for up to 4 device ports
+ */
+#define MAX_PNETID_LEN 16 /* Max.length of a single port PNETID */
+#define MAX_PNETID_PORTS (PNETIDS_LEN / MAX_PNETID_LEN)
+ /* Max. # of ports with a PNETID */
+
+/*
+ * Get the PNETIDs from a device.
+ * s390 hardware supports the definition of a so-called Physical Network
+ * Identifier (short PNETID) per network device port. These PNETIDs can be
+ * used to identify network devices that are attached to the same physical
+ * network (broadcast domain).
+ *
+ * The device can be
+ * - a ccwgroup device with all bundled subchannels having the same PNETID
+ * - a PCI attached network device
+ *
+ * Returns:
+ * 0: PNETIDs extracted from device.
+ * -ENOMEM: No memory to extract utility string.
+ * -EOPNOTSUPP: Device type without utility string support
+ */
+static int pnet_ids_by_device(struct device *dev, u8 *pnetids)
+{
+ memset(pnetids, 0, PNETIDS_LEN);
+ if (dev_is_ccwgroup(dev)) {
+ struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
+ u8 *util_str;
+
+ util_str = ccw_device_get_util_str(gdev->cdev[0], 0);
+ if (!util_str)
+ return -ENOMEM;
+ memcpy(pnetids, util_str, PNETIDS_LEN);
+ EBCASC(pnetids, PNETIDS_LEN);
+ kfree(util_str);
+ return 0;
+ }
+ if (dev_is_pci(dev)) {
+ struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
+
+ memcpy(pnetids, zdev->util_str, sizeof(zdev->util_str));
+ EBCASC(pnetids, sizeof(zdev->util_str));
+ return 0;
+ }
+ return -EOPNOTSUPP;
+}
+
+/*
+ * Extract the pnetid for a device port.
+ *
+ * Return 0 if a pnetid is found and -ENOENT otherwise.
+ */
+int pnet_id_by_dev_port(struct device *dev, unsigned short port, u8 *pnetid)
+{
+ u8 pnetids[MAX_PNETID_PORTS][MAX_PNETID_LEN];
+ static const u8 zero[MAX_PNETID_LEN] = { 0 };
+ int rc = 0;
+
+ if (!dev || port >= MAX_PNETID_PORTS)
+ return -ENOENT;
+
+ if (!pnet_ids_by_device(dev, (u8 *)pnetids) &&
+ memcmp(pnetids[port], zero, MAX_PNETID_LEN))
+ memcpy(pnetid, pnetids[port], MAX_PNETID_LEN);
+ else
+ rc = -ENOENT;
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(pnet_id_by_dev_port);
+
+MODULE_DESCRIPTION("pnetid determination from utility strings");
+MODULE_LICENSE("GPL");