hw/pci/pci: Factor out pci_bus_map_irqs() from pci_bus_irqs()

pci_bus_irqs() coupled together the assignment of pci_set_irq_fn and
pci_map_irq_fn to a PCI bus. This coupling gets in the way when the
pci_map_irq_fn is board-specific while the pci_set_irq_fn is device-
specific.

For example, both of QEMU's PIIX south bridge models have different
pci_map_irq_fn implementations which are board-specific rather than
device-specific. These implementations should therefore reside in board
code. The pci_set_irq_fn's, however, should stay in the device models
because they access memory internal to the model.

Factoring out pci_bus_map_irqs() from pci_bus_irqs() allows the
assignments to be decoupled, resolving the problem described above.

Note also how pci_vpb_realize() which gets touched in this commit
assigns different pci_map_irq_fn's depending on the board.

Signed-off-by: Bernhard Beschow <shentey@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230109172347.1830-5-shentey@gmail.com>
[PMD: Factor out in vfu_object_set_bus_irq()]
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

hw/i386/pc_q35.c

@@ -268,8 +268,8 @@ static void pc_q35_init(MachineState *machine)
     for (i = 0; i < GSI_NUM_PINS; i++) {
         qdev_connect_gpio_out_named(lpc_dev, ICH9_GPIO_GSI, i, x86ms->gsi[i]);
     }
-    pci_bus_irqs(host_bus, ich9_lpc_set_irq, ich9_lpc_map_irq, ich9_lpc,
-                 ICH9_LPC_NB_PIRQS);
+    pci_bus_irqs(host_bus, ich9_lpc_set_irq, ich9_lpc, ICH9_LPC_NB_PIRQS);
+    pci_bus_map_irqs(host_bus, ich9_lpc_map_irq);
     pci_bus_set_route_irq_fn(host_bus, ich9_route_intx_pin_to_irq);
     isa_bus = ich9_lpc->isa_bus;
 

hw/isa/piix3.c

@@ -384,8 +384,8 @@ static void piix3_realize(PCIDevice *dev, Error **errp)
         return;
     }
 
-    pci_bus_irqs(pci_bus, piix3_set_irq, pci_slot_get_pirq,
-                 piix3, PIIX_NUM_PIRQS);
+    pci_bus_irqs(pci_bus, piix3_set_irq, piix3, PIIX_NUM_PIRQS);
+    pci_bus_map_irqs(pci_bus, pci_slot_get_pirq);
     pci_bus_set_route_irq_fn(pci_bus, piix3_route_intx_pin_to_irq);
 }
 
@@ -420,8 +420,8 @@ static void piix3_xen_realize(PCIDevice *dev, Error **errp)
      * connected to the IOAPIC directly.
      * These additional routes can be discovered through ACPI.
      */
-    pci_bus_irqs(pci_bus, xen_piix3_set_irq, xen_pci_slot_get_pirq,
-                 piix3, XEN_PIIX_NUM_PIRQS);
+    pci_bus_irqs(pci_bus, xen_piix3_set_irq, piix3, XEN_PIIX_NUM_PIRQS);
+    pci_bus_map_irqs(pci_bus, xen_pci_slot_get_pirq);
 }
 
 static void piix3_xen_class_init(ObjectClass *klass, void *data)

hw/isa/piix4.c

@@ -271,7 +271,8 @@ static void piix4_realize(PCIDevice *dev, Error **errp)
     }
     qdev_connect_gpio_out(DEVICE(&s->pm), 0, s->isa[9]);
 
-    pci_bus_irqs(pci_bus, piix4_set_irq, pci_slot_get_pirq, s, PIIX_NUM_PIRQS);
+    pci_bus_irqs(pci_bus, piix4_set_irq, s, PIIX_NUM_PIRQS);
+    pci_bus_map_irqs(pci_bus, pci_slot_get_pirq);
 }
 
 static void piix4_init(Object *obj)

hw/pci-host/raven.c

@@ -258,7 +258,8 @@ static void raven_pcihost_realizefn(DeviceState *d, Error **errp)
 
     qdev_init_gpio_in(d, raven_change_gpio, 1);
 
-    pci_bus_irqs(&s->pci_bus, raven_set_irq, raven_map_irq, s, PCI_NUM_PINS);
+    pci_bus_irqs(&s->pci_bus, raven_set_irq, s, PCI_NUM_PINS);
+    pci_bus_map_irqs(&s->pci_bus, raven_map_irq);
 
     memory_region_init_io(&h->conf_mem, OBJECT(h), &pci_host_conf_le_ops, s,
                           "pci-conf-idx", 4);

hw/pci-host/versatile.c

@@ -422,7 +422,8 @@ static void pci_vpb_realize(DeviceState *dev, Error **errp)
         mapfn = pci_vpb_map_irq;
     }
 
-    pci_bus_irqs(&s->pci_bus, pci_vpb_set_irq, mapfn, s->irq, 4);
+    pci_bus_irqs(&s->pci_bus, pci_vpb_set_irq, s->irq, 4);
+    pci_bus_map_irqs(&s->pci_bus, mapfn);
 
     /* Our memory regions are:
      * 0 : our control registers

hw/pci/pci.c

@@ -280,6 +280,7 @@ static void pci_change_irq_level(PCIDevice *pci_dev, int irq_num, int change)
     PCIBus *bus;
     for (;;) {
         bus = pci_get_bus(pci_dev);
+        assert(bus->map_irq);
         irq_num = bus->map_irq(pci_dev, irq_num);
         if (bus->set_irq)
             break;
@@ -518,16 +519,20 @@ void pci_root_bus_cleanup(PCIBus *bus)
     qbus_unrealize(BUS(bus));
 }
 
-void pci_bus_irqs(PCIBus *bus, pci_set_irq_fn set_irq, pci_map_irq_fn map_irq,
+void pci_bus_irqs(PCIBus *bus, pci_set_irq_fn set_irq,
                   void *irq_opaque, int nirq)
 {
     bus->set_irq = set_irq;
-    bus->map_irq = map_irq;
     bus->irq_opaque = irq_opaque;
     bus->nirq = nirq;
     bus->irq_count = g_malloc0(nirq * sizeof(bus->irq_count[0]));
 }
 
+void pci_bus_map_irqs(PCIBus *bus, pci_map_irq_fn map_irq)
+{
+    bus->map_irq = map_irq;
+}
+
 void pci_bus_irqs_cleanup(PCIBus *bus)
 {
     bus->set_irq = NULL;
@@ -549,7 +554,8 @@ PCIBus *pci_register_root_bus(DeviceState *parent, const char *name,
 
     bus = pci_root_bus_new(parent, name, address_space_mem,
                            address_space_io, devfn_min, typename);
-    pci_bus_irqs(bus, set_irq, map_irq, irq_opaque, nirq);
+    pci_bus_irqs(bus, set_irq, irq_opaque, nirq);
+    pci_bus_map_irqs(bus, map_irq);
     return bus;
 }
 

hw/remote/machine.c

@@ -63,8 +63,9 @@ static void remote_machine_init(MachineState *machine)
     } else {
         remote_iohub_init(&s->iohub);
 
-        pci_bus_irqs(pci_host->bus, remote_iohub_set_irq, remote_iohub_map_irq,
+        pci_bus_irqs(pci_host->bus, remote_iohub_set_irq,
                      &s->iohub, REMOTE_IOHUB_NB_PIRQS);
+        pci_bus_map_irqs(pci_host->bus, remote_iohub_map_irq);
     }
 
     qbus_set_hotplug_handler(BUS(pci_host->bus), OBJECT(s));

hw/remote/vfio-user-obj.c

@@ -665,8 +665,8 @@ void vfu_object_set_bus_irq(PCIBus *pci_bus)
     int bus_num = pci_bus_num(pci_bus);
     int max_bdf = PCI_BUILD_BDF(bus_num, PCI_DEVFN_MAX - 1);
 
-    pci_bus_irqs(pci_bus, vfu_object_set_irq, vfu_object_map_irq, pci_bus,
-                 max_bdf);
+    pci_bus_irqs(pci_bus, vfu_object_set_irq, pci_bus, max_bdf);
+    pci_bus_map_irqs(pci_bus, vfu_object_map_irq);
 }
 
 static int vfu_object_device_reset(vfu_ctx_t *vfu_ctx, vfu_reset_type_t type)

include/hw/pci/pci.h

@@ -282,8 +282,9 @@ PCIBus *pci_root_bus_new(DeviceState *parent, const char *name,
                          MemoryRegion *address_space_io,
                          uint8_t devfn_min, const char *typename);
 void pci_root_bus_cleanup(PCIBus *bus);
-void pci_bus_irqs(PCIBus *bus, pci_set_irq_fn set_irq, pci_map_irq_fn map_irq,
+void pci_bus_irqs(PCIBus *bus, pci_set_irq_fn set_irq,
                   void *irq_opaque, int nirq);
+void pci_bus_map_irqs(PCIBus *bus, pci_map_irq_fn map_irq);
 void pci_bus_irqs_cleanup(PCIBus *bus);
 int pci_bus_get_irq_level(PCIBus *bus, int irq_num);
 /* 0 <= pin <= 3 0 = INTA, 1 = INTB, 2 = INTC, 3 = INTD */