xref: /OK3568_Linux_fs/kernel/arch/s390/pci/pci_iov.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * Copyright IBM Corp. 2020
4*4882a593Smuzhiyun  *
5*4882a593Smuzhiyun  * Author(s):
6*4882a593Smuzhiyun  *   Niklas Schnelle <schnelle@linux.ibm.com>
7*4882a593Smuzhiyun  *
8*4882a593Smuzhiyun  */
9*4882a593Smuzhiyun 
10*4882a593Smuzhiyun #define KMSG_COMPONENT "zpci"
11*4882a593Smuzhiyun #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
12*4882a593Smuzhiyun 
13*4882a593Smuzhiyun #include <linux/kernel.h>
14*4882a593Smuzhiyun #include <linux/pci.h>
15*4882a593Smuzhiyun 
16*4882a593Smuzhiyun #include "pci_iov.h"
17*4882a593Smuzhiyun 
18*4882a593Smuzhiyun static struct resource iov_res = {
19*4882a593Smuzhiyun 	.name	= "PCI IOV res",
20*4882a593Smuzhiyun 	.start	= 0,
21*4882a593Smuzhiyun 	.end	= -1,
22*4882a593Smuzhiyun 	.flags	= IORESOURCE_MEM,
23*4882a593Smuzhiyun };
24*4882a593Smuzhiyun 
zpci_iov_map_resources(struct pci_dev * pdev)25*4882a593Smuzhiyun void zpci_iov_map_resources(struct pci_dev *pdev)
26*4882a593Smuzhiyun {
27*4882a593Smuzhiyun 	resource_size_t len;
28*4882a593Smuzhiyun 	int i;
29*4882a593Smuzhiyun 
30*4882a593Smuzhiyun 	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
31*4882a593Smuzhiyun 		int bar = i + PCI_IOV_RESOURCES;
32*4882a593Smuzhiyun 
33*4882a593Smuzhiyun 		len = pci_resource_len(pdev, bar);
34*4882a593Smuzhiyun 		if (!len)
35*4882a593Smuzhiyun 			continue;
36*4882a593Smuzhiyun 		pdev->resource[bar].parent = &iov_res;
37*4882a593Smuzhiyun 	}
38*4882a593Smuzhiyun }
39*4882a593Smuzhiyun 
zpci_iov_remove_virtfn(struct pci_dev * pdev,int vfn)40*4882a593Smuzhiyun void zpci_iov_remove_virtfn(struct pci_dev *pdev, int vfn)
41*4882a593Smuzhiyun {
42*4882a593Smuzhiyun 	pci_lock_rescan_remove();
43*4882a593Smuzhiyun 	/* Linux' vfid's start at 0 vfn at 1 */
44*4882a593Smuzhiyun 	pci_iov_remove_virtfn(pdev->physfn, vfn - 1);
45*4882a593Smuzhiyun 	pci_unlock_rescan_remove();
46*4882a593Smuzhiyun }
47*4882a593Smuzhiyun 
zpci_iov_link_virtfn(struct pci_dev * pdev,struct pci_dev * virtfn,int vfid)48*4882a593Smuzhiyun static int zpci_iov_link_virtfn(struct pci_dev *pdev, struct pci_dev *virtfn, int vfid)
49*4882a593Smuzhiyun {
50*4882a593Smuzhiyun 	int rc;
51*4882a593Smuzhiyun 
52*4882a593Smuzhiyun 	rc = pci_iov_sysfs_link(pdev, virtfn, vfid);
53*4882a593Smuzhiyun 	if (rc)
54*4882a593Smuzhiyun 		return rc;
55*4882a593Smuzhiyun 
56*4882a593Smuzhiyun 	virtfn->is_virtfn = 1;
57*4882a593Smuzhiyun 	virtfn->multifunction = 0;
58*4882a593Smuzhiyun 	virtfn->physfn = pci_dev_get(pdev);
59*4882a593Smuzhiyun 
60*4882a593Smuzhiyun 	return 0;
61*4882a593Smuzhiyun }
62*4882a593Smuzhiyun 
zpci_iov_setup_virtfn(struct zpci_bus * zbus,struct pci_dev * virtfn,int vfn)63*4882a593Smuzhiyun int zpci_iov_setup_virtfn(struct zpci_bus *zbus, struct pci_dev *virtfn, int vfn)
64*4882a593Smuzhiyun {
65*4882a593Smuzhiyun 	int i, cand_devfn;
66*4882a593Smuzhiyun 	struct zpci_dev *zdev;
67*4882a593Smuzhiyun 	struct pci_dev *pdev;
68*4882a593Smuzhiyun 	int vfid = vfn - 1; /* Linux' vfid's start at 0 vfn at 1*/
69*4882a593Smuzhiyun 	int rc = 0;
70*4882a593Smuzhiyun 
71*4882a593Smuzhiyun 	if (!zbus->multifunction)
72*4882a593Smuzhiyun 		return 0;
73*4882a593Smuzhiyun 
74*4882a593Smuzhiyun 	/* If the parent PF for the given VF is also configured in the
75*4882a593Smuzhiyun 	 * instance, it must be on the same zbus.
76*4882a593Smuzhiyun 	 * We can then identify the parent PF by checking what
77*4882a593Smuzhiyun 	 * devfn the VF would have if it belonged to that PF using the PF's
78*4882a593Smuzhiyun 	 * stride and offset. Only if this candidate devfn matches the
79*4882a593Smuzhiyun 	 * actual devfn will we link both functions.
80*4882a593Smuzhiyun 	 */
81*4882a593Smuzhiyun 	for (i = 0; i < ZPCI_FUNCTIONS_PER_BUS; i++) {
82*4882a593Smuzhiyun 		zdev = zbus->function[i];
83*4882a593Smuzhiyun 		if (zdev && zdev->is_physfn) {
84*4882a593Smuzhiyun 			pdev = pci_get_slot(zbus->bus, zdev->devfn);
85*4882a593Smuzhiyun 			if (!pdev)
86*4882a593Smuzhiyun 				continue;
87*4882a593Smuzhiyun 			cand_devfn = pci_iov_virtfn_devfn(pdev, vfid);
88*4882a593Smuzhiyun 			if (cand_devfn == virtfn->devfn) {
89*4882a593Smuzhiyun 				rc = zpci_iov_link_virtfn(pdev, virtfn, vfid);
90*4882a593Smuzhiyun 				/* balance pci_get_slot() */
91*4882a593Smuzhiyun 				pci_dev_put(pdev);
92*4882a593Smuzhiyun 				break;
93*4882a593Smuzhiyun 			}
94*4882a593Smuzhiyun 			/* balance pci_get_slot() */
95*4882a593Smuzhiyun 			pci_dev_put(pdev);
96*4882a593Smuzhiyun 		}
97*4882a593Smuzhiyun 	}
98*4882a593Smuzhiyun 	return rc;
99*4882a593Smuzhiyun }
100