piix4: Add an i8259 Interrupt Controller as specified in datasheet

Add ISA irqs as piix4 gpio in, and CPU interrupt request as piix4 gpio out.
Remove i8259 instanciated in malta board, to not have it twice.

We can also remove the now unused piix4_init() function.

Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Message-Id: <20171216090228.28505-8-hpoussin@reactos.org>
Reviewed-by: Aleksandar Markovic <amarkovic@wavecomp.com>
[PMD: rebased, updated includes, use ISA_NUM_IRQS in for loop]
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

hw/isa/piix4.c

@@ -24,6 +24,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "hw/irq.h"
 #include "hw/i386/pc.h"
 #include "hw/pci/pci.h"
 #include "hw/isa/isa.h"
@@ -36,6 +37,8 @@ PCIDevice *piix4_dev;
 
 typedef struct PIIX4State {
     PCIDevice dev;
+    qemu_irq cpu_intr;
+    qemu_irq *isa;
 
     /* Reset Control Register */
     MemoryRegion rcr_mem;
@@ -94,6 +97,18 @@ static const VMStateDescription vmstate_piix4 = {
     }
 };
 
+static void piix4_request_i8259_irq(void *opaque, int irq, int level)
+{
+    PIIX4State *s = opaque;
+    qemu_set_irq(s->cpu_intr, level);
+}
+
+static void piix4_set_i8259_irq(void *opaque, int irq, int level)
+{
+    PIIX4State *s = opaque;
+    qemu_set_irq(s->isa[irq], level);
+}
+
 static void piix4_rcr_write(void *opaque, hwaddr addr, uint64_t val,
                             unsigned int len)
 {
@@ -127,29 +142,35 @@ static const MemoryRegionOps piix4_rcr_ops = {
 static void piix4_realize(PCIDevice *dev, Error **errp)
 {
     PIIX4State *s = PIIX4_PCI_DEVICE(dev);
+    ISABus *isa_bus;
+    qemu_irq *i8259_out_irq;
 
-    if (!isa_bus_new(DEVICE(dev), pci_address_space(dev),
+    isa_bus = isa_bus_new(DEVICE(dev), pci_address_space(dev),
-                     pci_address_space_io(dev), errp)) {
+                          pci_address_space_io(dev), errp);
+    if (!isa_bus) {
         return;
     }
 
+    qdev_init_gpio_in_named(DEVICE(dev), piix4_set_i8259_irq,
+                            "isa", ISA_NUM_IRQS);
+    qdev_init_gpio_out_named(DEVICE(dev), &s->cpu_intr,
+                             "intr", 1);
+
     memory_region_init_io(&s->rcr_mem, OBJECT(dev), &piix4_rcr_ops, s,
                           "reset-control", 1);
     memory_region_add_subregion_overlap(pci_address_space_io(dev),
                                         RCR_IOPORT, &s->rcr_mem, 1);
 
+    /* initialize i8259 pic */
+    i8259_out_irq = qemu_allocate_irqs(piix4_request_i8259_irq, s, 1);
+    s->isa = i8259_init(isa_bus, *i8259_out_irq);
+
+    /* initialize ISA irqs */
+    isa_bus_irqs(isa_bus, s->isa);
+
     piix4_dev = dev;
 }
 
-int piix4_init(PCIBus *bus, ISABus **isa_bus, int devfn)
-{
-    PCIDevice *d;
-
-    d = pci_create_simple_multifunction(bus, devfn, true, "PIIX4");
-    *isa_bus = ISA_BUS(qdev_get_child_bus(DEVICE(d), "isa.0"));
-    return d->devfn;
-}
-
 static void piix4_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);

hw/mips/mips_malta.c

@@ -97,7 +97,7 @@ typedef struct {
     SysBusDevice parent_obj;
 
     MIPSCPSState cps;
-    qemu_irq *i8259;
+    qemu_irq i8259[ISA_NUM_IRQS];
 } MaltaState;
 
 static ISADevice *pit;
@@ -1235,8 +1235,8 @@ void mips_malta_init(MachineState *machine)
     int64_t kernel_entry, bootloader_run_addr;
     PCIBus *pci_bus;
     ISABus *isa_bus;
-    qemu_irq *isa_irq;
     qemu_irq cbus_irq, i8259_irq;
+    PCIDevice *pci;
     int piix4_devfn;
     I2CBus *smbus;
     DriveInfo *dinfo;
@@ -1407,30 +1407,24 @@ void mips_malta_init(MachineState *machine)
     /* Board ID = 0x420 (Malta Board with CoreLV) */
     stl_p(memory_region_get_ram_ptr(bios_copy) + 0x10, 0x00000420);
 
-    /*
-     * We have a circular dependency problem: pci_bus depends on isa_irq,
-     * isa_irq is provided by i8259, i8259 depends on ISA, ISA depends
-     * on piix4, and piix4 depends on pci_bus.  To stop the cycle we have
-     * qemu_irq_proxy() adds an extra bit of indirection, allowing us
-     * to resolve the isa_irq -> i8259 dependency after i8259 is initialized.
-     */
-    isa_irq = qemu_irq_proxy(&s->i8259, 16);
-
     /* Northbridge */
-    pci_bus = gt64120_register(isa_irq);
+    pci_bus = gt64120_register(s->i8259);
 
     /* Southbridge */
     ide_drive_get(hd, ARRAY_SIZE(hd));
 
-    piix4_devfn = piix4_init(pci_bus, &isa_bus, 80);
+    pci = pci_create_simple_multifunction(pci_bus, PCI_DEVFN(10, 0),
+                                          true, "PIIX4");
+    dev = DEVICE(pci);
+    isa_bus = ISA_BUS(qdev_get_child_bus(dev, "isa.0"));
+    piix4_devfn = pci->devfn;
 
-    /*
+    /* Interrupt controller */
-     * Interrupt controller
+    qdev_connect_gpio_out_named(dev, "intr", 0, i8259_irq);
-     * The 8259 is attached to the MIPS CPU INT0 pin, ie interrupt 2
+    for (int i = 0; i < ISA_NUM_IRQS; i++) {
-     */
+        s->i8259[i] = qdev_get_gpio_in_named(dev, "isa", i);
-    s->i8259 = i8259_init(isa_bus, i8259_irq);
+    }
 
-    isa_bus_irqs(isa_bus, s->i8259);
     pci_piix4_ide_init(pci_bus, hd, piix4_devfn + 1);
     pci_create_simple(pci_bus, piix4_devfn + 2, "piix4-usb-uhci");
     smbus = piix4_pm_init(pci_bus, piix4_devfn + 3, 0x1100,

include/hw/i386/pc.h

@@ -266,7 +266,6 @@ PCIBus *i440fx_init(const char *host_type, const char *pci_type,
 PCIBus *find_i440fx(void);
 /* piix4.c */
 extern PCIDevice *piix4_dev;
-int piix4_init(PCIBus *bus, ISABus **isa_bus, int devfn);
 
 /* pc_sysfw.c */
 void pc_system_flash_create(PCMachineState *pcms);