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// 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;
}
/**
* zpci_iov_find_parent_pf - Find the parent PF, if any, of the given function
* @zbus: The bus that the PCI function is on, or would be added on
* @zdev: The PCI function
*
* Finds the parent PF, if it exists and is configured, of the given PCI function
* and increments its refcount. Th PF is searched for on the provided bus so the
* caller has to ensure that this is the correct bus to search. This function may
* be used before adding the PCI function to a zbus.
*
* Return: Pointer to the struct pci_dev of the parent PF or NULL if it not
* found. If the function is not a VF or has no RequesterID information,
* NULL is returned as well.
*/
struct pci_dev *zpci_iov_find_parent_pf(struct zpci_bus *zbus, struct zpci_dev *zdev)
{
int i, vfid, devfn, cand_devfn;
struct pci_dev *pdev;
if (!zbus->multifunction)
return NULL;
/* Non-VFs and VFs without RID available don't have a parent */
if (!zdev->vfn || !zdev->rid_available)
return NULL;
/* Linux vfid starts at 0 vfn at 1 */
vfid = zdev->vfn - 1;
devfn = zdev->rid & ZPCI_RID_MASK_DEVFN;
/*
* 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 == devfn)
return pdev;
/* balance pci_get_slot() */
pci_dev_put(pdev);
}
}
return NULL;
}
int zpci_iov_setup_virtfn(struct zpci_bus *zbus, struct pci_dev *virtfn, int vfn)
{
struct zpci_dev *zdev = to_zpci(virtfn);
struct pci_dev *pdev_pf;
int rc = 0;
pdev_pf = zpci_iov_find_parent_pf(zbus, zdev);
if (pdev_pf) {
/* Linux' vfids start at 0 while zdev->vfn starts at 1 */
rc = zpci_iov_link_virtfn(pdev_pf, virtfn, zdev->vfn - 1);
pci_dev_put(pdev_pf);
}
return rc;
}
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