drivers/xen/pci.c

   1 /*
   2  * Copyright (c) 2009, Intel Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Author: Weidong Han <weidong.han@intel.com>
  18  */
  19
  20 #include <linux/pci.h>
  21 #include <linux/acpi.h>
  22 #include <linux/pci-acpi.h>
  23 #include <xen/xen.h>
  24 #include <xen/interface/physdev.h>
  25 #include <xen/interface/xen.h>
  26
  27 #include <asm/xen/hypervisor.h>
  28 #include <asm/xen/hypercall.h>
  29 #include "../pci/pci.h"
  30 #ifdef CONFIG_PCI_MMCONFIG
  31 #include <asm/pci_x86.h>
  32
  33 static int xen_mcfg_late(void);
  34 #endif
  35
  36 static bool __read_mostly pci_seg_supported = true;
  37
  38 static int xen_add_device(struct device *dev)
  39 {
  40         int r;
  41         struct pci_dev *pci_dev = to_pci_dev(dev);
  42 #ifdef CONFIG_PCI_IOV
  43         struct pci_dev *physfn = pci_dev->physfn;
  44 #endif
  45 #ifdef CONFIG_PCI_MMCONFIG
  46         static bool pci_mcfg_reserved = false;
  47         /*
  48          * Reserve MCFG areas in Xen on first invocation due to this being
  49          * potentially called from inside of acpi_init immediately after
  50          * MCFG table has been finally parsed.
  51          */
  52         if (!pci_mcfg_reserved) {
  53                 xen_mcfg_late();
  54                 pci_mcfg_reserved = true;
  55         }
  56 #endif
  57         if (pci_seg_supported) {
  58                 struct {
  59                         struct physdev_pci_device_add add;
  60                         uint32_t pxm;
  61                 } add_ext = {
  62                         .add.seg = pci_domain_nr(pci_dev->bus),
  63                         .add.bus = pci_dev->bus->number,
  64                         .add.devfn = pci_dev->devfn
  65                 };
  66                 struct physdev_pci_device_add *add = &add_ext.add;
  67
  68 #ifdef CONFIG_ACPI
  69                 acpi_handle handle;
  70 #endif
  71
  72 #ifdef CONFIG_PCI_IOV
  73                 if (pci_dev->is_virtfn) {
  74                         add->flags = XEN_PCI_DEV_VIRTFN;
  75                         add->physfn.bus = physfn->bus->number;
  76                         add->physfn.devfn = physfn->devfn;
  77                 } else
  78 #endif
  79                 if (pci_ari_enabled(pci_dev->bus) && PCI_SLOT(pci_dev->devfn))
  80                         add->flags = XEN_PCI_DEV_EXTFN;
  81
  82 #ifdef CONFIG_ACPI
  83                 handle = ACPI_HANDLE(&pci_dev->dev);
  84 #ifdef CONFIG_PCI_IOV
  85                 if (!handle && pci_dev->is_virtfn)
  86                         handle = ACPI_HANDLE(physfn->bus->bridge);
  87 #endif
  88                 if (!handle) {
  89                         /*
  90                          * This device was not listed in the ACPI name space at
  91                          * all. Try to get acpi handle of parent pci bus.
  92                          */
  93                         struct pci_bus *pbus;
  94                         for (pbus = pci_dev->bus; pbus; pbus = pbus->parent) {
  95                                 handle = acpi_pci_get_bridge_handle(pbus);
  96                                 if (handle)
  97                                         break;
  98                         }
  99                 }
 100                 if (handle) {
 101                         acpi_status status;
 102
 103                         do {
 104                                 unsigned long long pxm;
 105
 106                                 status = acpi_evaluate_integer(handle, "_PXM",
 107                                                                NULL, &pxm);
 108                                 if (ACPI_SUCCESS(status)) {
 109                                         add->optarr[0] = pxm;
 110                                         add->flags |= XEN_PCI_DEV_PXM;
 111                                         break;
 112                                 }
 113                                 status = acpi_get_parent(handle, &handle);
 114                         } while (ACPI_SUCCESS(status));
 115                 }
 116 #endif /* CONFIG_ACPI */
 117
 118                 r = HYPERVISOR_physdev_op(PHYSDEVOP_pci_device_add, add);
 119                 if (r != -ENOSYS)
 120                         return r;
 121                 pci_seg_supported = false;
 122         }
 123
 124         if (pci_domain_nr(pci_dev->bus))
 125                 r = -ENOSYS;
 126 #ifdef CONFIG_PCI_IOV
 127         else if (pci_dev->is_virtfn) {
 128                 struct physdev_manage_pci_ext manage_pci_ext = {
 129                         .bus            = pci_dev->bus->number,
 130                         .devfn          = pci_dev->devfn,
 131                         .is_virtfn      = 1,
 132                         .physfn.bus     = physfn->bus->number,
 133                         .physfn.devfn   = physfn->devfn,
 134                 };
 135
 136                 r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add_ext,
 137                         &manage_pci_ext);
 138         }
 139 #endif
 140         else if (pci_ari_enabled(pci_dev->bus) && PCI_SLOT(pci_dev->devfn)) {
 141                 struct physdev_manage_pci_ext manage_pci_ext = {
 142                         .bus            = pci_dev->bus->number,
 143                         .devfn          = pci_dev->devfn,
 144                         .is_extfn       = 1,
 145                 };
 146
 147                 r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add_ext,
 148                         &manage_pci_ext);
 149         } else {
 150                 struct physdev_manage_pci manage_pci = {
 151                         .bus    = pci_dev->bus->number,
 152                         .devfn  = pci_dev->devfn,
 153                 };
 154
 155                 r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_add,
 156                         &manage_pci);
 157         }
 158
 159         return r;
 160 }
 161
 162 static int xen_remove_device(struct device *dev)
 163 {
 164         int r;
 165         struct pci_dev *pci_dev = to_pci_dev(dev);
 166
 167         if (pci_seg_supported) {
 168                 struct physdev_pci_device device = {
 169                         .seg = pci_domain_nr(pci_dev->bus),
 170                         .bus = pci_dev->bus->number,
 171                         .devfn = pci_dev->devfn
 172                 };
 173
 174                 r = HYPERVISOR_physdev_op(PHYSDEVOP_pci_device_remove,
 175                                           &device);
 176         } else if (pci_domain_nr(pci_dev->bus))
 177                 r = -ENOSYS;
 178         else {
 179                 struct physdev_manage_pci manage_pci = {
 180                         .bus = pci_dev->bus->number,
 181                         .devfn = pci_dev->devfn
 182                 };
 183
 184                 r = HYPERVISOR_physdev_op(PHYSDEVOP_manage_pci_remove,
 185                                           &manage_pci);
 186         }
 187
 188         return r;
 189 }
 190
 191 static int xen_pci_notifier(struct notifier_block *nb,
 192                             unsigned long action, void *data)
 193 {
 194         struct device *dev = data;
 195         int r = 0;
 196
 197         switch (action) {
 198         case BUS_NOTIFY_ADD_DEVICE:
 199                 r = xen_add_device(dev);
 200                 break;
 201         case BUS_NOTIFY_DEL_DEVICE:
 202                 r = xen_remove_device(dev);
 203                 break;
 204         default:
 205                 return NOTIFY_DONE;
 206         }
 207         if (r)
 208                 dev_err(dev, "Failed to %s - passthrough or MSI/MSI-X might fail!\n",
 209                         action == BUS_NOTIFY_ADD_DEVICE ? "add" :
 210                         (action == BUS_NOTIFY_DEL_DEVICE ? "delete" : "?"));
 211         return NOTIFY_OK;
 212 }
 213
 214 static struct notifier_block device_nb = {
 215         .notifier_call = xen_pci_notifier,
 216 };
 217
 218 static int __init register_xen_pci_notifier(void)
 219 {
 220         if (!xen_initial_domain())
 221                 return 0;
 222
 223         return bus_register_notifier(&pci_bus_type, &device_nb);
 224 }
 225
 226 arch_initcall(register_xen_pci_notifier);
 227
 228 #ifdef CONFIG_PCI_MMCONFIG
 229 static int xen_mcfg_late(void)
 230 {
 231         struct pci_mmcfg_region *cfg;
 232         int rc;
 233
 234         if (!xen_initial_domain())
 235                 return 0;
 236
 237         if ((pci_probe & PCI_PROBE_MMCONF) == 0)
 238                 return 0;
 239
 240         if (list_empty(&pci_mmcfg_list))
 241                 return 0;
 242
 243         /* Check whether they are in the right area. */
 244         list_for_each_entry(cfg, &pci_mmcfg_list, list) {
 245                 struct physdev_pci_mmcfg_reserved r;
 246
 247                 r.address = cfg->address;
 248                 r.segment = cfg->segment;
 249                 r.start_bus = cfg->start_bus;
 250                 r.end_bus = cfg->end_bus;
 251                 r.flags = XEN_PCI_MMCFG_RESERVED;
 252
 253                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_pci_mmcfg_reserved, &r);
 254                 switch (rc) {
 255                 case 0:
 256                 case -ENOSYS:
 257                         continue;
 258
 259                 default:
 260                         pr_warn("Failed to report MMCONFIG reservation"
 261                                 " state for %s to hypervisor"
 262                                 " (%d)\n",
 263                                 cfg->name, rc);
 264                 }
 265         }
 266         return 0;
 267 }
 268 #endif