arch/s390/pci/pci_iov.c

   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
  18 static struct resource iov_res = {
  19         .name   = "PCI IOV res",
  20         .start  = 0,
  21         .end    = -1,
  22         .flags  = IORESOURCE_MEM,
  23 };
  24
  25 void 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
  40 void 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
  48 static 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
  63 int 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 }