drivers/xen/pci.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2009, Intel Corporation.
   4  *
   5  * Author: Weidong Han <weidong.han@intel.com>
   6  */
   7
   8 #include <linux/pci.h>
   9 #include <linux/acpi.h>
  10 #include <linux/pci-acpi.h>
  11 #include <xen/xen.h>
  12 #include <xen/interface/physdev.h>
  13 #include <xen/interface/xen.h>
  14
  15 #include <asm/xen/hypervisor.h>
  16 #include <asm/xen/hypercall.h>
  17 #include "../pci/pci.h"
  18 #ifdef CONFIG_PCI_MMCONFIG
  19 #include <asm/pci_x86.h>
  20 #endif
  21
  22 static bool __read_mostly pci_seg_supported = true;
  23
  24 static int xen_add_device(struct device *dev)
  25 {
  26         int r;
  27         struct pci_dev *pci_dev = to_pci_dev(dev);
  28 #ifdef CONFIG_PCI_IOV
  29         struct pci_dev *physfn = pci_dev->physfn;
  30 #endif
  31
  32         if (pci_seg_supported) {
  33                 struct {
  34                         struct physdev_pci_device_add add;
  35                         uint32_t pxm;
  36                 } add_ext = {
  37                         .add.seg = pci_domain_nr(pci_dev->bus),
  38                         .add.bus = pci_dev->bus->number,
  39                         .add.devfn = pci_dev->devfn
  40                 };
  41                 struct physdev_pci_device_add *add = &add_ext.add;
  42
  43 #ifdef CONFIG_ACPI
  44                 acpi_handle handle;
  45 #endif
  46
  47 #ifdef CONFIG_PCI_IOV
  48                 if (pci_dev->is_virtfn) {
  49                         add->flags = XEN_PCI_DEV_VIRTFN;
  50                         add->physfn.bus = physfn->bus->number;
  51                         add->physfn.devfn = physfn->devfn;
  52                 } else
  53 #endif
  54                 if (pci_ari_enabled(pci_dev->bus) && PCI_SLOT(pci_dev->devfn))
  55                         add->flags = XEN_PCI_DEV_EXTFN;
  56
  57 #ifdef CONFIG_ACPI
  58                 handle = ACPI_HANDLE(&pci_dev->dev);
  59 #ifdef CONFIG_PCI_IOV
  60                 if (!handle && pci_dev->is_virtfn)
  61                         handle = ACPI_HANDLE(physfn->bus->bridge);
  62 #endif
  63                 if (!handle) {
  64                         /*
  65                          * This device was not listed in the ACPI name space at
  66                          * all. Try to get acpi handle of parent pci bus.
  67                          */
  68                         struct pci_bus *pbus;
  69                         for (pbus = pci_dev->bus; pbus; pbus = pbus->parent) {
  70                                 handle = acpi_pci_get_bridge_handle(pbus);
  71                                 if (handle)
  72                                         break;
  73                         }
  74                 }
  75                 if (handle) {
  76                         acpi_status status;
  77
  78                         do {
  79                                 unsigned long long pxm;
  80
  81                                 status = acpi_evaluate_integer(handle, "_PXM",
  82                                                                NULL, &pxm);
  83                                 if (ACPI_SUCCESS(status)) {
  84                                         add->optarr[0] = pxm;
  85                                         add->flags |= XEN_PCI_DEV_PXM;
  86                                         break;
  87                                 }
  88                                 status = acpi_get_parent(handle, &handle);
  89                         } while (ACPI_SUCCESS(status));
  90                 }
  91 #endif /* CONFIG_ACPI */
  92
  93                 r = HYPERVISOR_physdev_op(PHYSDEVOP_pci_device_add, add);
  94                 if (r != -ENOSYS)
  95                         return r;
  96                 pci_seg_supported = false;
  97         }
  98
  99         if (pci_domain_nr(pci_dev->bus))
 100                 r = -ENOSYS;
 101 #ifdef CONFIG_PCI_IOV
 102         else if (pci_dev->is_virtfn) {
 103                 struct physdev_manage_pci_ext manage_pci_ext = {
 104                         .bus            = pci_dev->bus->number,
 105                         .devfn          = pci_dev->devfn,
 106                         .is_virtfn      = 1,
 107                         .physfn.bus     = physfn->bus->number,
 108                         .physfn.devfn   = physfn->devfn,
 109                 };
 110
 111                 r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add_ext,
 112                         &manage_pci_ext);
 113         }
 114 #endif
 115         else if (pci_ari_enabled(pci_dev->bus) && PCI_SLOT(pci_dev->devfn)) {
 116                 struct physdev_manage_pci_ext manage_pci_ext = {
 117                         .bus            = pci_dev->bus->number,
 118                         .devfn          = pci_dev->devfn,
 119                         .is_extfn       = 1,
 120                 };
 121
 122                 r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add_ext,
 123                         &manage_pci_ext);
 124         } else {
 125                 struct physdev_manage_pci manage_pci = {
 126                         .bus    = pci_dev->bus->number,
 127                         .devfn  = pci_dev->devfn,
 128                 };
 129
 130                 r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add,
 131                         &manage_pci);
 132         }
 133
 134         return r;
 135 }
 136
 137 static int xen_remove_device(struct device *dev)
 138 {
 139         int r;
 140         struct pci_dev *pci_dev = to_pci_dev(dev);
 141
 142         if (pci_seg_supported) {
 143                 struct physdev_pci_device device = {
 144                         .seg = pci_domain_nr(pci_dev->bus),
 145                         .bus = pci_dev->bus->number,
 146                         .devfn = pci_dev->devfn
 147                 };
 148
 149                 r = HYPERVISOR_physdev_op(PHYSDEVOP_pci_device_remove,
 150                                           &device);
 151         } else if (pci_domain_nr(pci_dev->bus))
 152                 r = -ENOSYS;
 153         else {
 154                 struct physdev_manage_pci manage_pci = {
 155                         .bus = pci_dev->bus->number,
 156                         .devfn = pci_dev->devfn
 157                 };
 158
 159                 r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_remove,
 160                                           &manage_pci);
 161         }
 162
 163         return r;
 164 }
 165
 166 static int xen_pci_notifier(struct notifier_block *nb,
 167                             unsigned long action, void *data)
 168 {
 169         struct device *dev = data;
 170         int r = 0;
 171
 172         switch (action) {
 173         case BUS_NOTIFY_ADD_DEVICE:
 174                 r = xen_add_device(dev);
 175                 break;
 176         case BUS_NOTIFY_DEL_DEVICE:
 177                 r = xen_remove_device(dev);
 178                 break;
 179         default:
 180                 return NOTIFY_DONE;
 181         }
 182         if (r)
 183                 dev_err(dev, "Failed to %s - passthrough or MSI/MSI-X might fail!\n",
 184                         action == BUS_NOTIFY_ADD_DEVICE ? "add" :
 185                         (action == BUS_NOTIFY_DEL_DEVICE ? "delete" : "?"));
 186         return NOTIFY_OK;
 187 }
 188
 189 static struct notifier_block device_nb = {
 190         .notifier_call = xen_pci_notifier,
 191 };
 192
 193 static int __init register_xen_pci_notifier(void)
 194 {
 195         if (!xen_initial_domain())
 196                 return 0;
 197
 198         return bus_register_notifier(&pci_bus_type, &device_nb);
 199 }
 200
 201 arch_initcall(register_xen_pci_notifier);
 202
 203 #ifdef CONFIG_PCI_MMCONFIG
 204 static int __init xen_mcfg_late(void)
 205 {
 206         struct pci_mmcfg_region *cfg;
 207         int rc;
 208
 209         if (!xen_initial_domain())
 210                 return 0;
 211
 212         if ((pci_probe & PCI_PROBE_MMCONF) == 0)
 213                 return 0;
 214
 215         if (list_empty(&pci_mmcfg_list))
 216                 return 0;
 217
 218         /* Check whether they are in the right area. */
 219         list_for_each_entry(cfg, &pci_mmcfg_list, list) {
 220                 struct physdev_pci_mmcfg_reserved r;
 221
 222                 r.address = cfg->address;
 223                 r.segment = cfg->segment;
 224                 r.start_bus = cfg->start_bus;
 225                 r.end_bus = cfg->end_bus;
 226                 r.flags = XEN_PCI_MMCFG_RESERVED;
 227
 228                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_pci_mmcfg_reserved, &r);
 229                 switch (rc) {
 230                 case 0:
 231                 case -ENOSYS:
 232                         continue;
 233
 234                 default:
 235                         pr_warn("Failed to report MMCONFIG reservation"
 236                                 " state for %s to hypervisor"
 237                                 " (%d)\n",
 238                                 cfg->name, rc);
 239                 }
 240         }
 241         return 0;
 242 }
 243 /*
 244  * Needs to be done after acpi_init which are subsys_initcall.
 245  */
 246 subsys_initcall_sync(xen_mcfg_late);
 247 #endif