[Qemu-devel] [PATCH v2 2/3] 40p: use OR gate to wire up raven PCI interrupts

[Mark Cave-Ayland]

According to the PReP specification section 6.1.6 "System Interrupt
Assignments", all PCI interrupts are routed via IRQ 15.

Instead of mapping each PCI IRQ separately, we introduce an OR gate within the
raven PCI host bridge and then wire the single output of the OR gate to the
interrupt controller.

Note that whilst the (now deprecated) PReP machine still exists we still need
to preserve the old IRQ routing. This is done by adding a new "is-legacy-prep"
property to the raven PCI host bridge which is set to true for the PReP
machine.

Signed-off-by: Mark Cave-Ayland <address@hidden>
---
 hw/pci-host/prep.c | 25 +++++++++++++++++++++++--
 hw/ppc/prep.c      |  4 +---
 2 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/hw/pci-host/prep.c b/hw/pci-host/prep.c
index 9b36f19c97..b1b6b16bad 100644
--- a/hw/pci-host/prep.c
+++ b/hw/pci-host/prep.c
@@ -32,6 +32,7 @@
 #include "hw/pci/pci_host.h"
 #include "hw/i386/pc.h"
 #include "hw/loader.h"
+#include "hw/or-irq.h"
 #include "exec/address-spaces.h"
 #include "elf.h"
 
@@ -55,6 +56,7 @@ typedef struct RavenPCIState {
 typedef struct PRePPCIState {
     PCIHostState parent_obj;
 
+    qemu_or_irq *or_irq;
     qemu_irq pci_irqs[PCI_NUM_PINS];
     PCIBus pci_bus;
     AddressSpace pci_io_as;
@@ -69,6 +71,7 @@ typedef struct PRePPCIState {
     RavenPCIState pci_dev;
 
     int contiguous_map;
+    bool is_legacy_prep;
 } PREPPCIState;
 
 #define BIOS_SIZE (1 * MiB)
@@ -222,8 +225,23 @@ static void raven_pcihost_realizefn(DeviceState *d, Error 
**errp)
     MemoryRegion *address_space_mem = get_system_memory();
     int i;
 
-    for (i = 0; i < PCI_NUM_PINS; i++) {
-        sysbus_init_irq(dev, &s->pci_irqs[i]);
+    if (s->is_legacy_prep) {
+        for (i = 0; i < PCI_NUM_PINS; i++) {
+            sysbus_init_irq(dev, &s->pci_irqs[i]);
+        }
+    } else {
+        /* According to PReP specification section 6.1.6 "System Interrupt
+         * Assignments", all PCI interrupts are routed via IRQ 15 */
+        s->or_irq = OR_IRQ(object_new(TYPE_OR_IRQ));
+        object_property_set_int(OBJECT(s->or_irq), PCI_NUM_PINS, "num-lines",
+                                &error_fatal);
+        object_property_set_bool(OBJECT(s->or_irq), true, "realized",
+                                 &error_fatal);
+        sysbus_init_irq(dev, &s->or_irq->out_irq);
+
+        for (i = 0; i < PCI_NUM_PINS; i++) {
+            s->pci_irqs[i] = qdev_get_gpio_in(DEVICE(s->or_irq), i);
+        }
     }
 
     qdev_init_gpio_in(d, raven_change_gpio, 1);
@@ -382,6 +400,9 @@ static Property raven_pcihost_properties[] = {
     DEFINE_PROP_UINT32("elf-machine", PREPPCIState, pci_dev.elf_machine,
                        EM_NONE),
     DEFINE_PROP_STRING("bios-name", PREPPCIState, pci_dev.bios_name),
+    /* Temporary workaround until legacy prep machine is removed */
+    DEFINE_PROP_BOOL("is-legacy-prep", PREPPCIState, is_legacy_prep,
+                     false),
     DEFINE_PROP_END_OF_LIST()
 };
 
diff --git a/hw/ppc/prep.c b/hw/ppc/prep.c
index b0ea20416e..615865e46c 100644
--- a/hw/ppc/prep.c
+++ b/hw/ppc/prep.c
@@ -502,6 +502,7 @@ static void ppc_prep_init(MachineState *machine)
     }
     qdev_prop_set_string(dev, "bios-name", bios_name);
     qdev_prop_set_uint32(dev, "elf-machine", PPC_ELF_MACHINE);
+    qdev_prop_set_bit(dev, "is-legacy-prep", true);
     pcihost = PCI_HOST_BRIDGE(dev);
     object_property_add_child(qdev_get_machine(), "raven", OBJECT(dev), NULL);
     qdev_init_nofail(dev);
@@ -669,9 +670,6 @@ static void ibm_40p_init(MachineState *machine)
     qdev_connect_gpio_out(dev, 0,
                           cpu->env.irq_inputs[PPC6xx_INPUT_INT]);
     sysbus_connect_irq(pcihost, 0, qdev_get_gpio_in(dev, 15));
-    sysbus_connect_irq(pcihost, 1, qdev_get_gpio_in(dev, 13));
-    sysbus_connect_irq(pcihost, 2, qdev_get_gpio_in(dev, 15));
-    sysbus_connect_irq(pcihost, 3, qdev_get_gpio_in(dev, 13));
     isa_bus = ISA_BUS(qdev_get_child_bus(dev, "isa.0"));
 
     /* Memory controller */
-- 
2.11.0