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 "hw/acpi/pcihp.h"
  28
  29 #include "hw/hw.h"
  30 #include "hw/i386/pc.h"
  31 #include "hw/pci/pci.h"
  32 #include "hw/acpi/acpi.h"
  33 #include "sysemu/sysemu.h"
  34 #include "qemu/range.h"
  35 #include "exec/ioport.h"
  36 #include "exec/address-spaces.h"
  37 #include "hw/pci/pci_bus.h"
  38 #include "qom/qom-qobject.h"
  39 #include "qapi/qmp/qint.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_PCI_HOTPLUG_STATUS 2
  50 #define ACPI_PCIHP_ADDR 0xae00
  51 #define ACPI_PCIHP_SIZE 0x0014
  52 #define ACPI_PCIHP_LEGACY_SIZE 0x000f
  53 #define PCI_UP_BASE 0x0000
  54 #define PCI_DOWN_BASE 0x0004
  55 #define PCI_EJ_BASE 0x0008
  56 #define PCI_RMV_BASE 0x000c
  57 #define PCI_SEL_BASE 0x0010
  58
  59 typedef struct AcpiPciHpFind {
  60     int bsel;
  61     PCIBus *bus;
  62 } AcpiPciHpFind;
  63
  64 static int acpi_pcihp_get_bsel(PCIBus *bus)
  65 {
  66     Error *local_err = NULL;
  67     int64_t bsel = object_property_get_int(OBJECT(bus), ACPI_PCIHP_PROP_BSEL,
  68                                            &local_err);
  69
  70     if (local_err || bsel < 0 || bsel >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
  71         if (local_err) {
  72             error_free(local_err);
  73         }
  74         return -1;
  75     } else {
  76         return bsel;
  77     }
  78 }
  79
  80 static void acpi_pcihp_test_hotplug_bus(PCIBus *bus, void *opaque)
  81 {
  82     AcpiPciHpFind *find = opaque;
  83     if (find->bsel == acpi_pcihp_get_bsel(bus)) {
  84         find->bus = bus;
  85     }
  86 }
  87
  88 static PCIBus *acpi_pcihp_find_hotplug_bus(AcpiPciHpState *s, int bsel)
  89 {
  90     AcpiPciHpFind find = { .bsel = bsel, .bus = NULL };
  91
  92     if (bsel < 0) {
  93         return NULL;
  94     }
  95
  96     pci_for_each_bus(s->root, acpi_pcihp_test_hotplug_bus, &find);
  97
  98     /* Make bsel 0 eject root bus if bsel property is not set,
  99      * for compatibility with non acpi setups.
 100      * TODO: really needed?
 101      */
 102     if (!bsel && !find.bus) {
 103         find.bus = s->root;
 104     }
 105     return find.bus;
 106 }
 107
 108 static bool acpi_pcihp_pc_no_hotplug(AcpiPciHpState *s, PCIDevice *dev)
 109 {
 110     PCIDeviceClass *pc = PCI_DEVICE_GET_CLASS(dev);
 111     DeviceClass *dc = DEVICE_GET_CLASS(dev);
 112     /*
 113      * ACPI doesn't allow hotplug of bridge devices.  Don't allow
 114      * hot-unplug of bridge devices unless they were added by hotplug
 115      * (and so, not described by acpi).
 116      */
 117     return (pc->is_bridge && !dev->qdev.hotplugged) || !dc->hotpluggable;
 118 }
 119
 120 static void acpi_pcihp_eject_slot(AcpiPciHpState *s, unsigned bsel, unsigned slots)
 121 {
 122     BusChild *kid, *next;
 123     int slot = ffs(slots) - 1;
 124     PCIBus *bus = acpi_pcihp_find_hotplug_bus(s, bsel);
 125
 126     if (!bus) {
 127         return;
 128     }
 129
 130     /* Mark request as complete */
 131     s->acpi_pcihp_pci_status[bsel].down &= ~(1U << slot);
 132     s->acpi_pcihp_pci_status[bsel].up &= ~(1U << slot);
 133
 134     QTAILQ_FOREACH_SAFE(kid, &bus->qbus.children, sibling, next) {
 135         DeviceState *qdev = kid->child;
 136         PCIDevice *dev = PCI_DEVICE(qdev);
 137         if (PCI_SLOT(dev->devfn) == slot) {
 138             if (!acpi_pcihp_pc_no_hotplug(s, dev)) {
 139                 object_unparent(OBJECT(qdev));
 140             }
 141         }
 142     }
 143 }
 144
 145 static void acpi_pcihp_update_hotplug_bus(AcpiPciHpState *s, int bsel)
 146 {
 147     BusChild *kid, *next;
 148     PCIBus *bus = acpi_pcihp_find_hotplug_bus(s, bsel);
 149
 150     /* Execute any pending removes during reset */
 151     while (s->acpi_pcihp_pci_status[bsel].down) {
 152         acpi_pcihp_eject_slot(s, bsel, s->acpi_pcihp_pci_status[bsel].down);
 153     }
 154
 155     s->acpi_pcihp_pci_status[bsel].hotplug_enable = ~0;
 156
 157     if (!bus) {
 158         return;
 159     }
 160     QTAILQ_FOREACH_SAFE(kid, &bus->qbus.children, sibling, next) {
 161         DeviceState *qdev = kid->child;
 162         PCIDevice *pdev = PCI_DEVICE(qdev);
 163         int slot = PCI_SLOT(pdev->devfn);
 164
 165         if (acpi_pcihp_pc_no_hotplug(s, pdev)) {
 166             s->acpi_pcihp_pci_status[bsel].hotplug_enable &= ~(1U << slot);
 167         }
 168     }
 169 }
 170
 171 static void acpi_pcihp_update(AcpiPciHpState *s)
 172 {
 173     int i;
 174
 175     for (i = 0; i < ACPI_PCIHP_MAX_HOTPLUG_BUS; ++i) {
 176         acpi_pcihp_update_hotplug_bus(s, i);
 177     }
 178 }
 179
 180 void acpi_pcihp_reset(AcpiPciHpState *s)
 181 {
 182     acpi_pcihp_update(s);
 183 }
 184
 185 void acpi_pcihp_device_plug_cb(ACPIREGS *ar, qemu_irq irq, AcpiPciHpState *s,
 186                                DeviceState *dev, Error **errp)
 187 {
 188     PCIDevice *pdev = PCI_DEVICE(dev);
 189     int slot = PCI_SLOT(pdev->devfn);
 190     int bsel = acpi_pcihp_get_bsel(pdev->bus);
 191     if (bsel < 0) {
 192         error_setg(errp, "Unsupported bus. Bus doesn't have property '"
 193                    ACPI_PCIHP_PROP_BSEL "' set");
 194         return;
 195     }
 196
 197     /* Don't send event when device is enabled during qemu machine creation:
 198      * it is present on boot, no hotplug event is necessary. We do send an
 199      * event when the device is disabled later. */
 200     if (!dev->hotplugged) {
 201         return;
 202     }
 203
 204     s->acpi_pcihp_pci_status[bsel].up |= (1U << slot);
 205
 206     ar->gpe.sts[0] |= ACPI_PCI_HOTPLUG_STATUS;
 207     acpi_update_sci(ar, irq);
 208 }
 209
 210 void acpi_pcihp_device_unplug_cb(ACPIREGS *ar, qemu_irq irq, AcpiPciHpState *s,
 211                                  DeviceState *dev, Error **errp)
 212 {
 213     PCIDevice *pdev = PCI_DEVICE(dev);
 214     int slot = PCI_SLOT(pdev->devfn);
 215     int bsel = acpi_pcihp_get_bsel(pdev->bus);
 216     if (bsel < 0) {
 217         error_setg(errp, "Unsupported bus. Bus doesn't have property '"
 218                    ACPI_PCIHP_PROP_BSEL "' set");
 219         return;
 220     }
 221
 222     s->acpi_pcihp_pci_status[bsel].down |= (1U << slot);
 223
 224     ar->gpe.sts[0] |= ACPI_PCI_HOTPLUG_STATUS;
 225     acpi_update_sci(ar, irq);
 226 }
 227
 228 static uint64_t pci_read(void *opaque, hwaddr addr, unsigned int size)
 229 {
 230     AcpiPciHpState *s = opaque;
 231     uint32_t val = 0;
 232     int bsel = s->hotplug_select;
 233
 234     if (bsel < 0 || bsel >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
 235         return 0;
 236     }
 237
 238     switch (addr) {
 239     case PCI_UP_BASE:
 240         val = s->acpi_pcihp_pci_status[bsel].up;
 241         if (!s->legacy_piix) {
 242             s->acpi_pcihp_pci_status[bsel].up = 0;
 243         }
 244         ACPI_PCIHP_DPRINTF("pci_up_read %" PRIu32 "\n", val);
 245         break;
 246     case PCI_DOWN_BASE:
 247         val = s->acpi_pcihp_pci_status[bsel].down;
 248         ACPI_PCIHP_DPRINTF("pci_down_read %" PRIu32 "\n", val);
 249         break;
 250     case PCI_EJ_BASE:
 251         /* No feature defined yet */
 252         ACPI_PCIHP_DPRINTF("pci_features_read %" PRIu32 "\n", val);
 253         break;
 254     case PCI_RMV_BASE:
 255         val = s->acpi_pcihp_pci_status[bsel].hotplug_enable;
 256         ACPI_PCIHP_DPRINTF("pci_rmv_read %" PRIu32 "\n", val);
 257         break;
 258     case PCI_SEL_BASE:
 259         val = s->hotplug_select;
 260         ACPI_PCIHP_DPRINTF("pci_sel_read %" PRIu32 "\n", val);
 261     default:
 262         break;
 263     }
 264
 265     return val;
 266 }
 267
 268 static void pci_write(void *opaque, hwaddr addr, uint64_t data,
 269                       unsigned int size)
 270 {
 271     AcpiPciHpState *s = opaque;
 272     switch (addr) {
 273     case PCI_EJ_BASE:
 274         if (s->hotplug_select >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
 275             break;
 276         }
 277         acpi_pcihp_eject_slot(s, s->hotplug_select, data);
 278         ACPI_PCIHP_DPRINTF("pciej write %" HWADDR_PRIx " <== %" PRIu64 "\n",
 279                       addr, data);
 280         break;
 281     case PCI_SEL_BASE:
 282         s->hotplug_select = data;
 283         ACPI_PCIHP_DPRINTF("pcisel write %" HWADDR_PRIx " <== %" PRIu64 "\n",
 284                       addr, data);
 285     default:
 286         break;
 287     }
 288 }
 289
 290 static const MemoryRegionOps acpi_pcihp_io_ops = {
 291     .read = pci_read,
 292     .write = pci_write,
 293     .endianness = DEVICE_LITTLE_ENDIAN,
 294     .valid = {
 295         .min_access_size = 4,
 296         .max_access_size = 4,
 297     },
 298 };
 299
 300 void acpi_pcihp_init(AcpiPciHpState *s, PCIBus *root_bus,
 301                      MemoryRegion *address_space_io, bool bridges_enabled)
 302 {
 303     uint16_t io_size = ACPI_PCIHP_SIZE;
 304
 305     s->root= root_bus;
 306     s->legacy_piix = !bridges_enabled;
 307
 308     if (s->legacy_piix) {
 309         unsigned *bus_bsel = g_malloc(sizeof *bus_bsel);
 310
 311         io_size = ACPI_PCIHP_LEGACY_SIZE;
 312
 313         *bus_bsel = ACPI_PCIHP_BSEL_DEFAULT;
 314         object_property_add_uint32_ptr(OBJECT(root_bus), ACPI_PCIHP_PROP_BSEL,
 315                                        bus_bsel, NULL);
 316     }
 317
 318     memory_region_init_io(&s->io, NULL, &acpi_pcihp_io_ops, s,
 319                           "acpi-pci-hotplug", io_size);
 320     memory_region_add_subregion(address_space_io, ACPI_PCIHP_ADDR, &s->io);
 321 }
 322
 323 const VMStateDescription vmstate_acpi_pcihp_pci_status = {
 324     .name = "acpi_pcihp_pci_status",
 325     .version_id = 1,
 326     .minimum_version_id = 1,
 327     .fields = (VMStateField[]) {
 328         VMSTATE_UINT32(up, AcpiPciHpPciStatus),
 329         VMSTATE_UINT32(down, AcpiPciHpPciStatus),
 330         VMSTATE_END_OF_LIST()
 331     }
 332 };