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 PCI_HOTPLUG_ADDR 0xae00
  50 #define PCI_HOTPLUG_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     QObject *o = object_property_get_qobject(OBJECT(bus),
  65                                              ACPI_PCIHP_PROP_BSEL, NULL);
  66     int64_t bsel = -1;
  67     if (o) {
  68         bsel = qint_get_int(qobject_to_qint(o));
  69     }
  70     if (bsel < 0) {
  71         return -1;
  72     }
  73     return bsel;
  74 }
  75
  76 static void acpi_pcihp_test_hotplug_bus(PCIBus *bus, void *opaque)
  77 {
  78     AcpiPciHpFind *find = opaque;
  79     if (find->bsel == acpi_pcihp_get_bsel(bus)) {
  80         find->bus = bus;
  81     }
  82 }
  83
  84 static PCIBus *acpi_pcihp_find_hotplug_bus(AcpiPciHpState *s, int bsel)
  85 {
  86     AcpiPciHpFind find = { .bsel = bsel, .bus = NULL };
  87
  88     if (bsel < 0) {
  89         return NULL;
  90     }
  91
  92     pci_for_each_bus(s->root, acpi_pcihp_test_hotplug_bus, &find);
  93
  94     /* Make bsel 0 eject root bus if bsel property is not set,
  95      * for compatibility with non acpi setups.
  96      * TODO: really needed?
  97      */
  98     if (!bsel && !find.bus) {
  99         find.bus = s->root;
 100     }
 101     return find.bus;
 102 }
 103
 104 static bool acpi_pcihp_pc_no_hotplug(AcpiPciHpState *s, PCIDevice *dev)
 105 {
 106     PCIDeviceClass *pc = PCI_DEVICE_GET_CLASS(dev);
 107     /*
 108      * ACPI doesn't allow hotplug of bridge devices.  Don't allow
 109      * hot-unplug of bridge devices unless they were added by hotplug
 110      * (and so, not described by acpi).
 111      */
 112     return (pc->is_bridge && !dev->qdev.hotplugged) || pc->no_hotplug;
 113 }
 114
 115 static void acpi_pcihp_eject_slot(AcpiPciHpState *s, unsigned bsel, unsigned slots)
 116 {
 117     BusChild *kid, *next;
 118     int slot = ffs(slots) - 1;
 119     PCIBus *bus = acpi_pcihp_find_hotplug_bus(s, bsel);
 120
 121     if (!bus) {
 122         return;
 123     }
 124
 125     /* Mark request as complete */
 126     s->acpi_pcihp_pci_status[bsel].down &= ~(1U << slot);
 127     s->acpi_pcihp_pci_status[bsel].up &= ~(1U << slot);
 128
 129     QTAILQ_FOREACH_SAFE(kid, &bus->qbus.children, sibling, next) {
 130         DeviceState *qdev = kid->child;
 131         PCIDevice *dev = PCI_DEVICE(qdev);
 132         if (PCI_SLOT(dev->devfn) == slot) {
 133             if (!acpi_pcihp_pc_no_hotplug(s, dev)) {
 134                 object_unparent(OBJECT(qdev));
 135             }
 136         }
 137     }
 138 }
 139
 140 static void acpi_pcihp_update_hotplug_bus(AcpiPciHpState *s, int bsel)
 141 {
 142     BusChild *kid, *next;
 143     PCIBus *bus = acpi_pcihp_find_hotplug_bus(s, bsel);
 144
 145     /* Execute any pending removes during reset */
 146     while (s->acpi_pcihp_pci_status[bsel].down) {
 147         acpi_pcihp_eject_slot(s, bsel, s->acpi_pcihp_pci_status[bsel].down);
 148     }
 149
 150     s->acpi_pcihp_pci_status[bsel].hotplug_enable = ~0;
 151
 152     if (!bus) {
 153         return;
 154     }
 155     QTAILQ_FOREACH_SAFE(kid, &bus->qbus.children, sibling, next) {
 156         DeviceState *qdev = kid->child;
 157         PCIDevice *pdev = PCI_DEVICE(qdev);
 158         int slot = PCI_SLOT(pdev->devfn);
 159
 160         if (acpi_pcihp_pc_no_hotplug(s, pdev)) {
 161             s->acpi_pcihp_pci_status[bsel].hotplug_enable &= ~(1U << slot);
 162         }
 163     }
 164 }
 165
 166 static void acpi_pcihp_update(AcpiPciHpState *s)
 167 {
 168     int i;
 169
 170     for (i = 0; i < ACPI_PCIHP_MAX_HOTPLUG_BUS; ++i) {
 171         acpi_pcihp_update_hotplug_bus(s, i);
 172     }
 173 }
 174
 175 void acpi_pcihp_reset(AcpiPciHpState *s)
 176 {
 177     acpi_pcihp_update(s);
 178 }
 179
 180 int acpi_pcihp_device_hotplug(AcpiPciHpState *s, PCIDevice *dev,
 181                               PCIHotplugState state)
 182 {
 183     int slot = PCI_SLOT(dev->devfn);
 184     int bsel = acpi_pcihp_get_bsel(dev->bus);
 185     if (bsel < 0) {
 186         return -1;
 187     }
 188
 189     /* Don't send event when device is enabled during qemu machine creation:
 190      * it is present on boot, no hotplug event is necessary. We do send an
 191      * event when the device is disabled later. */
 192     if (state == PCI_COLDPLUG_ENABLED) {
 193         return 0;
 194     }
 195
 196     if (state == PCI_HOTPLUG_ENABLED) {
 197         s->acpi_pcihp_pci_status[bsel].up |= (1U << slot);
 198     } else {
 199         s->acpi_pcihp_pci_status[bsel].down |= (1U << slot);
 200     }
 201
 202     return 0;
 203 }
 204
 205 static uint64_t pci_read(void *opaque, hwaddr addr, unsigned int size)
 206 {
 207     AcpiPciHpState *s = opaque;
 208     uint32_t val = 0;
 209     int bsel = s->hotplug_select;
 210
 211     if (bsel < 0 || bsel > ACPI_PCIHP_MAX_HOTPLUG_BUS) {
 212         return 0;
 213     }
 214
 215     switch (addr) {
 216     case PCI_UP_BASE:
 217         val = s->acpi_pcihp_pci_status[bsel].up;
 218         if (!s->legacy_piix) {
 219             s->acpi_pcihp_pci_status[bsel].up = 0;
 220         }
 221         ACPI_PCIHP_DPRINTF("pci_up_read %" PRIu32 "\n", val);
 222         break;
 223     case PCI_DOWN_BASE:
 224         val = s->acpi_pcihp_pci_status[bsel].down;
 225         ACPI_PCIHP_DPRINTF("pci_down_read %" PRIu32 "\n", val);
 226         break;
 227     case PCI_EJ_BASE:
 228         /* No feature defined yet */
 229         ACPI_PCIHP_DPRINTF("pci_features_read %" PRIu32 "\n", val);
 230         break;
 231     case PCI_RMV_BASE:
 232         val = s->acpi_pcihp_pci_status[bsel].hotplug_enable;
 233         ACPI_PCIHP_DPRINTF("pci_rmv_read %" PRIu32 "\n", val);
 234         break;
 235     case PCI_SEL_BASE:
 236         val = s->hotplug_select;
 237         ACPI_PCIHP_DPRINTF("pci_sel_read %" PRIu32 "\n", val);
 238     default:
 239         break;
 240     }
 241
 242     return val;
 243 }
 244
 245 static void pci_write(void *opaque, hwaddr addr, uint64_t data,
 246                       unsigned int size)
 247 {
 248     AcpiPciHpState *s = opaque;
 249     switch (addr) {
 250     case PCI_EJ_BASE:
 251         if (s->hotplug_select >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
 252             break;
 253         }
 254         acpi_pcihp_eject_slot(s, s->hotplug_select, data);
 255         ACPI_PCIHP_DPRINTF("pciej write %" HWADDR_PRIx " <== %" PRIu64 "\n",
 256                       addr, data);
 257         break;
 258     case PCI_SEL_BASE:
 259         s->hotplug_select = data;
 260         ACPI_PCIHP_DPRINTF("pcisel write %" HWADDR_PRIx " <== %" PRIu64 "\n",
 261                       addr, data);
 262     default:
 263         break;
 264     }
 265 }
 266
 267 static const MemoryRegionOps acpi_pcihp_io_ops = {
 268     .read = pci_read,
 269     .write = pci_write,
 270     .endianness = DEVICE_LITTLE_ENDIAN,
 271     .valid = {
 272         .min_access_size = 4,
 273         .max_access_size = 4,
 274     },
 275 };
 276
 277 void acpi_pcihp_init(AcpiPciHpState *s, PCIBus *root_bus,
 278                      MemoryRegion *address_space_io, bool bridges_enabled)
 279 {
 280     s->root= root_bus;
 281     s->legacy_piix = !bridges_enabled;
 282     memory_region_init_io(&s->io, NULL, &acpi_pcihp_io_ops, s,
 283                           "acpi-pci-hotplug",
 284                           PCI_HOTPLUG_SIZE);
 285     memory_region_add_subregion(address_space_io, PCI_HOTPLUG_ADDR, &s->io);
 286 }
 287
 288 const VMStateDescription vmstate_acpi_pcihp_pci_status = {
 289     .name = "acpi_pcihp_pci_status",
 290     .version_id = 1,
 291     .minimum_version_id = 1,
 292     .minimum_version_id_old = 1,
 293     .fields      = (VMStateField []) {
 294         VMSTATE_UINT32(up, AcpiPciHpPciStatus),
 295         VMSTATE_UINT32(down, AcpiPciHpPciStatus),
 296         VMSTATE_END_OF_LIST()
 297     }
 298 };