linuxdebug/arch/s390/pci/pci_iov.c

100 lines
2.2 KiB
C

// 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;
}