1 files changed, 99 insertions, 0 deletions
diff --git a/arch/s390/pci/pci_iov.c b/arch/s390/pci/pci_iov.c
new file mode 100644
index 000000000000..ead062bf2b41
--- /dev/null
+++ b/arch/s390/pci/pci_iov.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright IBM Corp. 2020
+ *
+ * Author(s):
+ *   Niklas Schnelle <schnelle@linux.ibm.com>
+ *
+ */
+
+#define KMSG_COMPONENT "zpci"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/pci.h>
+
+#include "pci_iov.h"
+
+static struct resource iov_res = {
+	.name	= "PCI IOV res",
+	.start	= 0,
+	.end	= -1,
+	.flags	= IORESOURCE_MEM,
+};
+
+void zpci_iov_map_resources(struct pci_dev *pdev)
+{
+	resource_size_t len;
+	int i;
+
+	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
+		int bar = i + PCI_IOV_RESOURCES;
+
+		len = pci_resource_len(pdev, bar);
+		if (!len)
+			continue;
+		pdev->resource[bar].parent = &iov_res;
+	}
+}
+
+void zpci_iov_remove_virtfn(struct pci_dev *pdev, int vfn)
+{
+	pci_lock_rescan_remove();
+	/* Linux' vfid's start at 0 vfn at 1 */
+	pci_iov_remove_virtfn(pdev->physfn, vfn - 1);
+	pci_unlock_rescan_remove();
+}
+
+static int zpci_iov_link_virtfn(struct pci_dev *pdev, struct pci_dev *virtfn, int vfid)
+{
+	int rc;
+
+	rc = pci_iov_sysfs_link(pdev, virtfn, vfid);
+	if (rc)
+		return rc;
+
+	virtfn->is_virtfn = 1;
+	virtfn->multifunction = 0;
+	virtfn->physfn = pci_dev_get(pdev);
+
+	return 0;
+}
+
+int zpci_iov_setup_virtfn(struct zpci_bus *zbus, struct pci_dev *virtfn, int vfn)
+{
+	int i, cand_devfn;
+	struct zpci_dev *zdev;
+	struct pci_dev *pdev;
+	int vfid = vfn - 1; /* Linux' vfid's start at 0 vfn at 1*/
+	int rc = 0;
+
+	if (!zbus->multifunction)
+		return 0;
+
+	/* If the parent PF for the given VF is also configured in the
+	 * instance, it must be on the same zbus.
+	 * We can then identify the parent PF by checking what
+	 * devfn the VF would have if it belonged to that PF using the PF's
+	 * stride and offset. Only if this candidate devfn matches the
+	 * actual devfn will we link both functions.
+	 */
+	for (i = 0; i < ZPCI_FUNCTIONS_PER_BUS; i++) {
+		zdev = zbus->function[i];
+		if (zdev && zdev->is_physfn) {
+			pdev = pci_get_slot(zbus->bus, zdev->devfn);
+			if (!pdev)
+				continue;
+			cand_devfn = pci_iov_virtfn_devfn(pdev, vfid);
+			if (cand_devfn == virtfn->devfn) {
+				rc = zpci_iov_link_virtfn(pdev, virtfn, vfid);
+				/* balance pci_get_slot() */
+				pci_dev_put(pdev);
+				break;
+			}
+			/* balance pci_get_slot() */
+			pci_dev_put(pdev);
+		}
+	}
+	return rc;
+}