pci: add standard bridge device

This adds support for a standard pci to pci bridge,
enabling support for more than 32 PCI devices in the system.
Device hotplug is supported by means of SHPC controller.
For guests with an SHPC driver, this allows robust hotplug
and even hotplug of nested bridges, up to 31 devices
per bridge.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

2 files changed, 175 insertions, 1 deletions

diff --git a/Makefile.objs b/Makefile.objs
index 5b97871..25400e9 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -213,7 +213,7 @@ hw-obj-$(CONFIG_VIRTIO) += virtio-console.o
 hw-obj-y += usb/libhw.o
 hw-obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o
 hw-obj-y += fw_cfg.o
-hw-obj-$(CONFIG_PCI) += pci.o pci_bridge.o
+hw-obj-$(CONFIG_PCI) += pci.o pci_bridge.o pci_bridge_dev.o
 hw-obj-$(CONFIG_PCI) += msix.o msi.o
 hw-obj-$(CONFIG_PCI) += shpc.o
 hw-obj-$(CONFIG_PCI) += slotid_cap.o
diff --git a/hw/pci_bridge_dev.c b/hw/pci_bridge_dev.c
new file mode 100644
index 0000000..eccaa58
--- /dev/null
+++ b/hw/pci_bridge_dev.c
@@ -0,0 +1,174 @@
+/*
+ * Standard PCI Bridge Device
+ *
+ * Copyright (c) 2011 Red Hat Inc. Author: Michael S. Tsirkin <mst@redhat.com>
+ *
+ * http://www.pcisig.com/specifications/conventional/pci_to_pci_bridge_architecture/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pci_bridge.h"
+#include "pci_ids.h"
+#include "msi.h"
+#include "shpc.h"
+#include "slotid_cap.h"
+#include "memory.h"
+#include "pci_internals.h"
+
+#define REDHAT_PCI_VENDOR_ID 0x1b36
+#define PCI_BRIDGE_DEV_VENDOR_ID REDHAT_PCI_VENDOR_ID
+#define PCI_BRIDGE_DEV_DEVICE_ID 0x1
+
+struct PCIBridgeDev {
+    PCIBridge bridge;
+    MemoryRegion bar;
+    uint8_t chassis_nr;
+#define PCI_BRIDGE_DEV_F_MSI_REQ 0
+    uint32_t flags;
+};
+typedef struct PCIBridgeDev PCIBridgeDev;
+
+/* Mapping mandated by PCI-to-PCI Bridge architecture specification,
+ * revision 1.2 */
+/* Table 9-1: Interrupt Binding for Devices Behind a Bridge */
+static int pci_bridge_dev_map_irq_fn(PCIDevice *dev, int irq_num)
+{
+    return (irq_num + PCI_SLOT(dev->devfn)) % PCI_NUM_PINS;
+}
+
+static int pci_bridge_dev_initfn(PCIDevice *dev)
+{
+    PCIBridge *br = DO_UPCAST(PCIBridge, dev, dev);
+    PCIBridgeDev *bridge_dev = DO_UPCAST(PCIBridgeDev, bridge, br);
+    int err;
+    pci_bridge_map_irq(br, NULL, pci_bridge_dev_map_irq_fn);
+    err = pci_bridge_initfn(dev);
+    if (err) {
+        goto bridge_error;
+    }
+    memory_region_init(&bridge_dev->bar, "shpc-bar", shpc_bar_size(dev));
+    err = shpc_init(dev, &br->sec_bus, &bridge_dev->bar, 0);
+    if (err) {
+        goto shpc_error;
+    }
+    err = slotid_cap_init(dev, 0, bridge_dev->chassis_nr, 0);
+    if (err) {
+        goto slotid_error;
+    }
+    if ((bridge_dev->flags & (1 << PCI_BRIDGE_DEV_F_MSI_REQ)) &&
+        msi_supported) {
+        err = msi_init(dev, 0, 1, true, true);
+        if (err < 0) {
+            goto msi_error;
+        }
+    }
+    /* TODO: spec recommends using 64 bit prefetcheable BAR.
+     * Check whether that works well. */
+    pci_register_bar(dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY |
+		     PCI_BASE_ADDRESS_MEM_TYPE_64, &bridge_dev->bar);
+    dev->config[PCI_INTERRUPT_PIN] = 0x1;
+    return 0;
+msi_error:
+    slotid_cap_cleanup(dev);
+slotid_error:
+    shpc_cleanup(dev, &bridge_dev->bar);
+shpc_error:
+    memory_region_destroy(&bridge_dev->bar);
+bridge_error:
+    return err;
+}
+
+static int pci_bridge_dev_exitfn(PCIDevice *dev)
+{
+    PCIBridge *br = DO_UPCAST(PCIBridge, dev, dev);
+    PCIBridgeDev *bridge_dev = DO_UPCAST(PCIBridgeDev, bridge, br);
+    int ret;
+    if (msi_present(dev)) {
+        msi_uninit(dev);
+    }
+    slotid_cap_cleanup(dev);
+    shpc_cleanup(dev, &bridge_dev->bar);
+    memory_region_destroy(&bridge_dev->bar);
+    ret = pci_bridge_exitfn(dev);
+    assert(!ret);
+    return 0;
+}
+
+static void pci_bridge_dev_write_config(PCIDevice *d,
+                                        uint32_t address, uint32_t val, int len)
+{
+    pci_bridge_write_config(d, address, val, len);
+    if (msi_present(d)) {
+        msi_write_config(d, address, val, len);
+    }
+    shpc_cap_write_config(d, address, val, len);
+}
+
+static void qdev_pci_bridge_dev_reset(DeviceState *qdev)
+{
+    PCIDevice *dev = DO_UPCAST(PCIDevice, qdev, qdev);
+    pci_bridge_reset(qdev);
+    if (msi_present(dev)) {
+        msi_reset(dev);
+    }
+    shpc_reset(dev);
+}
+
+static Property pci_bridge_dev_properties[] = {
+                    /* Note: 0 is not a legal chassis number. */
+    DEFINE_PROP_UINT8("chassis_nr", PCIBridgeDev, chassis_nr, 0),
+    DEFINE_PROP_BIT("msi", PCIBridgeDev, flags, PCI_BRIDGE_DEV_F_MSI_REQ, true),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static const VMStateDescription pci_bridge_dev_vmstate = {
+    .name = "pci_bridge",
+    .fields = (VMStateField[]) {
+        VMSTATE_PCI_DEVICE(bridge.dev, PCIBridgeDev),
+        SHPC_VMSTATE(bridge.dev.shpc, PCIBridgeDev),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void pci_bridge_dev_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
+    k->init = pci_bridge_dev_initfn;
+    k->exit = pci_bridge_dev_exitfn;
+    k->config_write = pci_bridge_dev_write_config;
+    k->vendor_id = PCI_BRIDGE_DEV_VENDOR_ID;
+    k->device_id = PCI_BRIDGE_DEV_DEVICE_ID;
+    k->class_id = PCI_CLASS_BRIDGE_PCI;
+    k->is_bridge = 1,
+    dc->desc = "Standard PCI Bridge";
+    dc->reset = qdev_pci_bridge_dev_reset;
+    dc->props = pci_bridge_dev_properties;
+    dc->vmsd = &pci_bridge_dev_vmstate;
+}
+
+static TypeInfo pci_bridge_dev_info = {
+    .name = "pci-bridge",
+    .parent        = TYPE_PCI_DEVICE,
+    .instance_size = sizeof(PCIBridgeDev),
+    .class_init = pci_bridge_dev_class_init,
+};
+
+static void pci_bridge_dev_register(void)
+{
+    type_register_static(&pci_bridge_dev_info);
+}
+
+type_init(pci_bridge_dev_register);