hw/acpi/pcihp.c

   1 /*
   2  * QEMU<->ACPI BIOS PCI hotplug interface
   3  *
   4  * QEMU supports PCI hotplug via ACPI. This module
   5  * implements the interface between QEMU and the ACPI BIOS.
   6  * Interface specification - see docs/specs/acpi_pci_hotplug.txt
   7  *
   8  * Copyright (c) 2013, Red Hat Inc, Michael S. Tsirkin (mst@redhat.com)
   9  * Copyright (c) 2006 Fabrice Bellard
  10  *
  11  * This library is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU Lesser General Public
  13  * License version 2 as published by the Free Software Foundation.
  14  *
  15  * This library is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public
  21  * License along with this library; if not, see <http://www.gnu.org/licenses/>
  22  *
  23  * Contributions after 2012-01-13 are licensed under the terms of the
  24  * GNU GPL, version 2 or (at your option) any later version.
  25  */
  26
  27 #include "qemu/osdep.h"
  28 #include "hw/acpi/pcihp.h"
  29
  30 #include "hw/hw.h"
  31 #include "hw/i386/pc.h"
  32 #include "hw/pci/pci.h"
  33 #include "hw/pci/pci_bridge.h"
  34 #include "hw/acpi/acpi.h"
  35 #include "sysemu/sysemu.h"
  36 #include "exec/address-spaces.h"
  37 #include "hw/pci/pci_bus.h"
  38 #include "qapi/error.h"
  39 #include "qom/qom-qobject.h"
  40
  41 //#define DEBUG
  42
  43 #ifdef DEBUG
  44 # define ACPI_PCIHP_DPRINTF(format, ...)     printf(format, ## __VA_ARGS__)
  45 #else
  46 # define ACPI_PCIHP_DPRINTF(format, ...)     do { } while (0)
  47 #endif
  48
  49 #define ACPI_PCIHP_ADDR 0xae00
  50 #define ACPI_PCIHP_SIZE 0x0014
  51 #define PCI_UP_BASE 0x0000
  52 #define PCI_DOWN_BASE 0x0004
  53 #define PCI_EJ_BASE 0x0008
  54 #define PCI_RMV_BASE 0x000c
  55 #define PCI_SEL_BASE 0x0010
  56
  57 typedef struct AcpiPciHpFind {
  58     int bsel;
  59     PCIBus *bus;
  60 } AcpiPciHpFind;
  61
  62 static int acpi_pcihp_get_bsel(PCIBus *bus)
  63 {
  64     Error *local_err = NULL;
  65     uint64_t bsel = object_property_get_uint(OBJECT(bus), ACPI_PCIHP_PROP_BSEL,
  66                                              &local_err);
  67
  68     if (local_err || bsel >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
  69         if (local_err) {
  70             error_free(local_err);
  71         }
  72         return -1;
  73     } else {
  74         return bsel;
  75     }
  76 }
  77
  78 /* Assign BSEL property to all buses.  In the future, this can be changed
  79  * to only assign to buses that support hotplug.
  80  */
  81 static void *acpi_set_bsel(PCIBus *bus, void *opaque)
  82 {
  83     unsigned *bsel_alloc = opaque;
  84     unsigned *bus_bsel;
  85
  86     if (qbus_is_hotpluggable(BUS(bus))) {
  87         bus_bsel = g_malloc(sizeof *bus_bsel);
  88
  89         *bus_bsel = (*bsel_alloc)++;
  90         object_property_add_uint32_ptr(OBJECT(bus), ACPI_PCIHP_PROP_BSEL,
  91                                        bus_bsel, &error_abort);
  92     }
  93
  94     return bsel_alloc;
  95 }
  96
  97 static void acpi_set_pci_info(void)
  98 {
  99     static bool bsel_is_set;
 100     PCIBus *bus;
 101     unsigned bsel_alloc = ACPI_PCIHP_BSEL_DEFAULT;
 102
 103     if (bsel_is_set) {
 104         return;
 105     }
 106     bsel_is_set = true;
 107
 108     bus = find_i440fx(); /* TODO: Q35 support */
 109     if (bus) {
 110         /* Scan all PCI buses. Set property to enable acpi based hotplug. */
 111         pci_for_each_bus_depth_first(bus, acpi_set_bsel, NULL, &bsel_alloc);
 112     }
 113 }
 114
 115 static void acpi_pcihp_test_hotplug_bus(PCIBus *bus, void *opaque)
 116 {
 117     AcpiPciHpFind *find = opaque;
 118     if (find->bsel == acpi_pcihp_get_bsel(bus)) {
 119         find->bus = bus;
 120     }
 121 }
 122
 123 static PCIBus *acpi_pcihp_find_hotplug_bus(AcpiPciHpState *s, int bsel)
 124 {
 125     AcpiPciHpFind find = { .bsel = bsel, .bus = NULL };
 126
 127     if (bsel < 0) {
 128         return NULL;
 129     }
 130
 131     pci_for_each_bus(s->root, acpi_pcihp_test_hotplug_bus, &find);
 132
 133     /* Make bsel 0 eject root bus if bsel property is not set,
 134      * for compatibility with non acpi setups.
 135      * TODO: really needed?
 136      */
 137     if (!bsel && !find.bus) {
 138         find.bus = s->root;
 139     }
 140     return find.bus;
 141 }
 142
 143 static bool acpi_pcihp_pc_no_hotplug(AcpiPciHpState *s, PCIDevice *dev)
 144 {
 145     PCIDeviceClass *pc = PCI_DEVICE_GET_CLASS(dev);
 146     DeviceClass *dc = DEVICE_GET_CLASS(dev);
 147     /*
 148      * ACPI doesn't allow hotplug of bridge devices.  Don't allow
 149      * hot-unplug of bridge devices unless they were added by hotplug
 150      * (and so, not described by acpi).
 151      */
 152     return (pc->is_bridge && !dev->qdev.hotplugged) || !dc->hotpluggable;
 153 }
 154
 155 static void acpi_pcihp_eject_slot(AcpiPciHpState *s, unsigned bsel, unsigned slots)
 156 {
 157     HotplugHandler *hotplug_ctrl;
 158     BusChild *kid, *next;
 159     int slot = ctz32(slots);
 160     PCIBus *bus = acpi_pcihp_find_hotplug_bus(s, bsel);
 161
 162     if (!bus) {
 163         return;
 164     }
 165
 166     /* Mark request as complete */
 167     s->acpi_pcihp_pci_status[bsel].down &= ~(1U << slot);
 168     s->acpi_pcihp_pci_status[bsel].up &= ~(1U << slot);
 169
 170     QTAILQ_FOREACH_SAFE(kid, &bus->qbus.children, sibling, next) {
 171         DeviceState *qdev = kid->child;
 172         PCIDevice *dev = PCI_DEVICE(qdev);
 173         if (PCI_SLOT(dev->devfn) == slot) {
 174             if (!acpi_pcihp_pc_no_hotplug(s, dev)) {
 175                 hotplug_ctrl = qdev_get_hotplug_handler(qdev);
 176                 hotplug_handler_unplug(hotplug_ctrl, qdev, &error_abort);
 177             }
 178         }
 179     }
 180 }
 181
 182 static void acpi_pcihp_update_hotplug_bus(AcpiPciHpState *s, int bsel)
 183 {
 184     BusChild *kid, *next;
 185     PCIBus *bus = acpi_pcihp_find_hotplug_bus(s, bsel);
 186
 187     /* Execute any pending removes during reset */
 188     while (s->acpi_pcihp_pci_status[bsel].down) {
 189         acpi_pcihp_eject_slot(s, bsel, s->acpi_pcihp_pci_status[bsel].down);
 190     }
 191
 192     s->acpi_pcihp_pci_status[bsel].hotplug_enable = ~0;
 193
 194     if (!bus) {
 195         return;
 196     }
 197     QTAILQ_FOREACH_SAFE(kid, &bus->qbus.children, sibling, next) {
 198         DeviceState *qdev = kid->child;
 199         PCIDevice *pdev = PCI_DEVICE(qdev);
 200         int slot = PCI_SLOT(pdev->devfn);
 201
 202         if (acpi_pcihp_pc_no_hotplug(s, pdev)) {
 203             s->acpi_pcihp_pci_status[bsel].hotplug_enable &= ~(1U << slot);
 204         }
 205     }
 206 }
 207
 208 static void acpi_pcihp_update(AcpiPciHpState *s)
 209 {
 210     int i;
 211
 212     for (i = 0; i < ACPI_PCIHP_MAX_HOTPLUG_BUS; ++i) {
 213         acpi_pcihp_update_hotplug_bus(s, i);
 214     }
 215 }
 216
 217 void acpi_pcihp_reset(AcpiPciHpState *s)
 218 {
 219     acpi_set_pci_info();
 220     acpi_pcihp_update(s);
 221 }
 222
 223 void acpi_pcihp_device_pre_plug_cb(HotplugHandler *hotplug_dev,
 224                                    DeviceState *dev, Error **errp)
 225 {
 226     /* Only hotplugged devices need the hotplug capability. */
 227     if (dev->hotplugged &&
 228         acpi_pcihp_get_bsel(pci_get_bus(PCI_DEVICE(dev))) < 0) {
 229         error_setg(errp, "Unsupported bus. Bus doesn't have property '"
 230                    ACPI_PCIHP_PROP_BSEL "' set");
 231         return;
 232     }
 233 }
 234
 235 void acpi_pcihp_device_plug_cb(HotplugHandler *hotplug_dev, AcpiPciHpState *s,
 236                                DeviceState *dev, Error **errp)
 237 {
 238     PCIDevice *pdev = PCI_DEVICE(dev);
 239     int slot = PCI_SLOT(pdev->devfn);
 240     int bsel;
 241
 242     /* Don't send event when device is enabled during qemu machine creation:
 243      * it is present on boot, no hotplug event is necessary. We do send an
 244      * event when the device is disabled later. */
 245     if (!dev->hotplugged) {
 246         /*
 247          * Overwrite the default hotplug handler with the ACPI PCI one
 248          * for cold plugged bridges only.
 249          */
 250         if (!s->legacy_piix &&
 251             object_dynamic_cast(OBJECT(dev), TYPE_PCI_BRIDGE)) {
 252             PCIBus *sec = pci_bridge_get_sec_bus(PCI_BRIDGE(pdev));
 253
 254             qbus_set_hotplug_handler(BUS(sec), OBJECT(hotplug_dev),
 255                                      &error_abort);
 256             /* We don't have to overwrite any other hotplug handler yet */
 257             assert(QLIST_EMPTY(&sec->child));
 258         }
 259
 260         return;
 261     }
 262
 263     bsel = acpi_pcihp_get_bsel(pci_get_bus(pdev));
 264     g_assert(bsel >= 0);
 265     s->acpi_pcihp_pci_status[bsel].up |= (1U << slot);
 266     acpi_send_event(DEVICE(hotplug_dev), ACPI_PCI_HOTPLUG_STATUS);
 267 }
 268
 269 void acpi_pcihp_device_unplug_cb(HotplugHandler *hotplug_dev, AcpiPciHpState *s,
 270                                  DeviceState *dev, Error **errp)
 271 {
 272     object_unparent(OBJECT(dev));
 273 }
 274
 275 void acpi_pcihp_device_unplug_request_cb(HotplugHandler *hotplug_dev,
 276                                          AcpiPciHpState *s, DeviceState *dev,
 277                                          Error **errp)
 278 {
 279     PCIDevice *pdev = PCI_DEVICE(dev);
 280     int slot = PCI_SLOT(pdev->devfn);
 281     int bsel = acpi_pcihp_get_bsel(pci_get_bus(pdev));
 282     if (bsel < 0) {
 283         error_setg(errp, "Unsupported bus. Bus doesn't have property '"
 284                    ACPI_PCIHP_PROP_BSEL "' set");
 285         return;
 286     }
 287
 288     s->acpi_pcihp_pci_status[bsel].down |= (1U << slot);
 289     acpi_send_event(DEVICE(hotplug_dev), ACPI_PCI_HOTPLUG_STATUS);
 290 }
 291
 292 static uint64_t pci_read(void *opaque, hwaddr addr, unsigned int size)
 293 {
 294     AcpiPciHpState *s = opaque;
 295     uint32_t val = 0;
 296     int bsel = s->hotplug_select;
 297
 298     if (bsel < 0 || bsel >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
 299         return 0;
 300     }
 301
 302     switch (addr) {
 303     case PCI_UP_BASE:
 304         val = s->acpi_pcihp_pci_status[bsel].up;
 305         if (!s->legacy_piix) {
 306             s->acpi_pcihp_pci_status[bsel].up = 0;
 307         }
 308         ACPI_PCIHP_DPRINTF("pci_up_read %" PRIu32 "\n", val);
 309         break;
 310     case PCI_DOWN_BASE:
 311         val = s->acpi_pcihp_pci_status[bsel].down;
 312         ACPI_PCIHP_DPRINTF("pci_down_read %" PRIu32 "\n", val);
 313         break;
 314     case PCI_EJ_BASE:
 315         /* No feature defined yet */
 316         ACPI_PCIHP_DPRINTF("pci_features_read %" PRIu32 "\n", val);
 317         break;
 318     case PCI_RMV_BASE:
 319         val = s->acpi_pcihp_pci_status[bsel].hotplug_enable;
 320         ACPI_PCIHP_DPRINTF("pci_rmv_read %" PRIu32 "\n", val);
 321         break;
 322     case PCI_SEL_BASE:
 323         val = s->hotplug_select;
 324         ACPI_PCIHP_DPRINTF("pci_sel_read %" PRIu32 "\n", val);
 325     default:
 326         break;
 327     }
 328
 329     return val;
 330 }
 331
 332 static void pci_write(void *opaque, hwaddr addr, uint64_t data,
 333                       unsigned int size)
 334 {
 335     AcpiPciHpState *s = opaque;
 336     switch (addr) {
 337     case PCI_EJ_BASE:
 338         if (s->hotplug_select >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
 339             break;
 340         }
 341         acpi_pcihp_eject_slot(s, s->hotplug_select, data);
 342         ACPI_PCIHP_DPRINTF("pciej write %" HWADDR_PRIx " <== %" PRIu64 "\n",
 343                       addr, data);
 344         break;
 345     case PCI_SEL_BASE:
 346         s->hotplug_select = s->legacy_piix ? ACPI_PCIHP_BSEL_DEFAULT : data;
 347         ACPI_PCIHP_DPRINTF("pcisel write %" HWADDR_PRIx " <== %" PRIu64 "\n",
 348                       addr, data);
 349     default:
 350         break;
 351     }
 352 }
 353
 354 static const MemoryRegionOps acpi_pcihp_io_ops = {
 355     .read = pci_read,
 356     .write = pci_write,
 357     .endianness = DEVICE_LITTLE_ENDIAN,
 358     .valid = {
 359         .min_access_size = 4,
 360         .max_access_size = 4,
 361     },
 362 };
 363
 364 void acpi_pcihp_init(Object *owner, AcpiPciHpState *s, PCIBus *root_bus,
 365                      MemoryRegion *address_space_io, bool bridges_enabled)
 366 {
 367     s->io_len = ACPI_PCIHP_SIZE;
 368     s->io_base = ACPI_PCIHP_ADDR;
 369
 370     s->root= root_bus;
 371     s->legacy_piix = !bridges_enabled;
 372
 373     memory_region_init_io(&s->io, owner, &acpi_pcihp_io_ops, s,
 374                           "acpi-pci-hotplug", s->io_len);
 375     memory_region_add_subregion(address_space_io, s->io_base, &s->io);
 376
 377     object_property_add_uint16_ptr(owner, ACPI_PCIHP_IO_BASE_PROP, &s->io_base,
 378                                    &error_abort);
 379     object_property_add_uint16_ptr(owner, ACPI_PCIHP_IO_LEN_PROP, &s->io_len,
 380                                    &error_abort);
 381 }
 382
 383 const VMStateDescription vmstate_acpi_pcihp_pci_status = {
 384     .name = "acpi_pcihp_pci_status",
 385     .version_id = 1,
 386     .minimum_version_id = 1,
 387     .fields = (VMStateField[]) {
 388         VMSTATE_UINT32(up, AcpiPciHpPciStatus),
 389         VMSTATE_UINT32(down, AcpiPciHpPciStatus),
 390         VMSTATE_END_OF_LIST()
 391     }
 392 };