1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright IBM Corp. 2020
4 *
5 * Author(s):
6 *   Niklas Schnelle <schnelle@linux.ibm.com>
7 *
8 */
9
10#define KMSG_COMPONENT "zpci"
11#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
12
13#include <linux/kernel.h>
14#include <linux/pci.h>
15
16#include "pci_iov.h"
17
18static struct resource iov_res = {
19	.name	= "PCI IOV res",
20	.start	= 0,
21	.end	= -1,
22	.flags	= IORESOURCE_MEM,
23};
24
25void zpci_iov_map_resources(struct pci_dev *pdev)
26{
27	resource_size_t len;
28	int i;
29
30	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
31		int bar = i + PCI_IOV_RESOURCES;
32
33		len = pci_resource_len(pdev, bar);
34		if (!len)
35			continue;
36		pdev->resource[bar].parent = &iov_res;
37	}
38}
39
40void zpci_iov_remove_virtfn(struct pci_dev *pdev, int vfn)
41{
42	pci_lock_rescan_remove();
43	/* Linux' vfid's start at 0 vfn at 1 */
44	pci_iov_remove_virtfn(pdev->physfn, vfn - 1);
45	pci_unlock_rescan_remove();
46}
47
48static int zpci_iov_link_virtfn(struct pci_dev *pdev, struct pci_dev *virtfn, int vfid)
49{
50	int rc;
51
52	rc = pci_iov_sysfs_link(pdev, virtfn, vfid);
53	if (rc)
54		return rc;
55
56	virtfn->is_virtfn = 1;
57	virtfn->multifunction = 0;
58	virtfn->physfn = pci_dev_get(pdev);
59
60	return 0;
61}
62
63int zpci_iov_setup_virtfn(struct zpci_bus *zbus, struct pci_dev *virtfn, int vfn)
64{
65	int i, cand_devfn;
66	struct zpci_dev *zdev;
67	struct pci_dev *pdev;
68	int vfid = vfn - 1; /* Linux' vfid's start at 0 vfn at 1*/
69	int rc = 0;
70
71	if (!zbus->multifunction)
72		return 0;
73
74	/* If the parent PF for the given VF is also configured in the
75	 * instance, it must be on the same zbus.
76	 * We can then identify the parent PF by checking what
77	 * devfn the VF would have if it belonged to that PF using the PF's
78	 * stride and offset. Only if this candidate devfn matches the
79	 * actual devfn will we link both functions.
80	 */
81	for (i = 0; i < ZPCI_FUNCTIONS_PER_BUS; i++) {
82		zdev = zbus->function[i];
83		if (zdev && zdev->is_physfn) {
84			pdev = pci_get_slot(zbus->bus, zdev->devfn);
85			if (!pdev)
86				continue;
87			cand_devfn = pci_iov_virtfn_devfn(pdev, vfid);
88			if (cand_devfn == virtfn->devfn) {
89				rc = zpci_iov_link_virtfn(pdev, virtfn, vfid);
90				/* balance pci_get_slot() */
91				pci_dev_put(pdev);
92				break;
93			}
94			/* balance pci_get_slot() */
95			pci_dev_put(pdev);
96		}
97	}
98	return rc;
99}
100