hw/pci-bridge/pci_expander_bridge.c

   1 /*
   2  * PCI Expander Bridge Device Emulation
   3  *
   4  * Copyright (C) 2015 Red Hat Inc
   5  *
   6  * Authors:
   7  *   Marcel Apfelbaum <marcel@redhat.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  10  * See the COPYING file in the top-level directory.
  11  */
  12
  13 #include "hw/pci/pci.h"
  14 #include "hw/pci/pci_bus.h"
  15 #include "hw/pci/pci_host.h"
  16 #include "hw/pci/pci_bus.h"
  17 #include "hw/i386/pc.h"
  18 #include "qemu/range.h"
  19 #include "qemu/error-report.h"
  20
  21 #define TYPE_PXB_BUS "pxb-bus"
  22 #define PXB_BUS(obj) OBJECT_CHECK(PXBBus, (obj), TYPE_PXB_BUS)
  23
  24 typedef struct PXBBus {
  25     /*< private >*/
  26     PCIBus parent_obj;
  27     /*< public >*/
  28
  29     char bus_path[8];
  30 } PXBBus;
  31
  32 #define TYPE_PXB_DEVICE "pxb"
  33 #define PXB_DEV(obj) OBJECT_CHECK(PXBDev, (obj), TYPE_PXB_DEVICE)
  34
  35 typedef struct PXBDev {
  36     /*< private >*/
  37     PCIDevice parent_obj;
  38     /*< public >*/
  39
  40     uint8_t bus_nr;
  41 } PXBDev;
  42
  43 #define TYPE_PXB_HOST "pxb-host"
  44
  45 static int pxb_bus_num(PCIBus *bus)
  46 {
  47     PXBDev *pxb = PXB_DEV(bus->parent_dev);
  48
  49     return pxb->bus_nr;
  50 }
  51
  52 static bool pxb_is_root(PCIBus *bus)
  53 {
  54     return true; /* by definition */
  55 }
  56
  57 static void pxb_bus_class_init(ObjectClass *class, void *data)
  58 {
  59     PCIBusClass *pbc = PCI_BUS_CLASS(class);
  60
  61     pbc->bus_num = pxb_bus_num;
  62     pbc->is_root = pxb_is_root;
  63 }
  64
  65 static const TypeInfo pxb_bus_info = {
  66     .name          = TYPE_PXB_BUS,
  67     .parent        = TYPE_PCI_BUS,
  68     .instance_size = sizeof(PXBBus),
  69     .class_init    = pxb_bus_class_init,
  70 };
  71
  72 static const char *pxb_host_root_bus_path(PCIHostState *host_bridge,
  73                                           PCIBus *rootbus)
  74 {
  75     PXBBus *bus = PXB_BUS(rootbus);
  76
  77     snprintf(bus->bus_path, 8, "0000:%02x", pxb_bus_num(rootbus));
  78     return bus->bus_path;
  79 }
  80
  81 static void pxb_host_class_init(ObjectClass *class, void *data)
  82 {
  83     DeviceClass *dc = DEVICE_CLASS(class);
  84     PCIHostBridgeClass *hc = PCI_HOST_BRIDGE_CLASS(class);
  85
  86     dc->fw_name = "pci";
  87     hc->root_bus_path = pxb_host_root_bus_path;
  88 }
  89
  90 static const TypeInfo pxb_host_info = {
  91     .name          = TYPE_PXB_HOST,
  92     .parent        = TYPE_PCI_HOST_BRIDGE,
  93     .class_init    = pxb_host_class_init,
  94 };
  95
  96 /*
  97  * Registers the PXB bus as a child of the i440fx root bus.
  98  *
  99  * Returns 0 on successs, -1 if i440fx host was not
 100  * found or the bus number is already in use.
 101  */
 102 static int pxb_register_bus(PCIDevice *dev, PCIBus *pxb_bus)
 103 {
 104     PCIBus *bus = dev->bus;
 105     int pxb_bus_num = pci_bus_num(pxb_bus);
 106
 107     if (bus->parent_dev) {
 108         error_report("PXB devices can be attached only to root bus.");
 109         return -1;
 110     }
 111
 112     QLIST_FOREACH(bus, &bus->child, sibling) {
 113         if (pci_bus_num(bus) == pxb_bus_num) {
 114             error_report("Bus %d is already in use.", pxb_bus_num);
 115             return -1;
 116         }
 117     }
 118     QLIST_INSERT_HEAD(&dev->bus->child, pxb_bus, sibling);
 119
 120     return 0;
 121 }
 122
 123 static int pxb_map_irq_fn(PCIDevice *pci_dev, int pin)
 124 {
 125     PCIDevice *pxb = pci_dev->bus->parent_dev;
 126
 127     /*
 128      * The bios does not index the pxb slot number when
 129      * it computes the IRQ because it resides on bus 0
 130      * and not on the current bus.
 131      * However QEMU routes the irq through bus 0 and adds
 132      * the pxb slot to the IRQ computation of the PXB
 133      * device.
 134      *
 135      * Synchronize between bios and QEMU by canceling
 136      * pxb's effect.
 137      */
 138     return pin - PCI_SLOT(pxb->devfn);
 139 }
 140
 141 static int pxb_dev_initfn(PCIDevice *dev)
 142 {
 143     PXBDev *pxb = PXB_DEV(dev);
 144     DeviceState *ds, *bds;
 145     PCIBus *bus;
 146     const char *dev_name = NULL;
 147
 148     if (dev->qdev.id && *dev->qdev.id) {
 149         dev_name = dev->qdev.id;
 150     }
 151
 152     ds = qdev_create(NULL, TYPE_PXB_HOST);
 153     bus = pci_bus_new(ds, "pxb-internal", NULL, NULL, 0, TYPE_PXB_BUS);
 154
 155     bus->parent_dev = dev;
 156     bus->address_space_mem = dev->bus->address_space_mem;
 157     bus->address_space_io = dev->bus->address_space_io;
 158     bus->map_irq = pxb_map_irq_fn;
 159
 160     bds = qdev_create(BUS(bus), "pci-bridge");
 161     bds->id = dev_name;
 162     qdev_prop_set_uint8(bds, "chassis_nr", pxb->bus_nr);
 163
 164     PCI_HOST_BRIDGE(ds)->bus = bus;
 165
 166     if (pxb_register_bus(dev, bus)) {
 167         return -EINVAL;
 168     }
 169
 170     qdev_init_nofail(ds);
 171     qdev_init_nofail(bds);
 172
 173     pci_word_test_and_set_mask(dev->config + PCI_STATUS,
 174                                PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
 175     pci_config_set_class(dev->config, PCI_CLASS_BRIDGE_HOST);
 176
 177     return 0;
 178 }
 179
 180 static Property pxb_dev_properties[] = {
 181     /* Note: 0 is not a legal a PXB bus number. */
 182     DEFINE_PROP_UINT8("bus_nr", PXBDev, bus_nr, 0),
 183     DEFINE_PROP_END_OF_LIST(),
 184 };
 185
 186 static void pxb_dev_class_init(ObjectClass *klass, void *data)
 187 {
 188     DeviceClass *dc = DEVICE_CLASS(klass);
 189     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
 190
 191     k->init = pxb_dev_initfn;
 192     k->vendor_id = PCI_VENDOR_ID_REDHAT;
 193     k->device_id = PCI_DEVICE_ID_REDHAT_PXB;
 194     k->class_id = PCI_CLASS_BRIDGE_HOST;
 195
 196     dc->desc = "PCI Expander Bridge";
 197     dc->props = pxb_dev_properties;
 198 }
 199
 200 static const TypeInfo pxb_dev_info = {
 201     .name          = TYPE_PXB_DEVICE,
 202     .parent        = TYPE_PCI_DEVICE,
 203     .instance_size = sizeof(PXBDev),
 204     .class_init    = pxb_dev_class_init,
 205 };
 206
 207 static void pxb_register_types(void)
 208 {
 209     type_register_static(&pxb_bus_info);
 210     type_register_static(&pxb_host_info);
 211     type_register_static(&pxb_dev_info);
 212 }
 213
 214 type_init(pxb_register_types)