[PATCH v3 20/29] hw/acpi/ged: Prepare the device to react to PCI hotplug events

[Eric Auger <eric.auger@redhat.com>]

QEMU will notify the OS about PCI hotplug/hotunplug events through
GED interrupts. Let the GED device handle a new PCI hotplug event.
On its occurrence it calls the \\_SB.PCI0.PCNT method with the BLCK
mutex held.

The GED device uses a dedicated MMIO region that will be mapped
by the machine code.

At this point the GED still does not support PCI device hotplug in
its TYPE_HOTPLUG_HANDLER implementation. This will come in a
subsequent patch.

Signed-off-by: Eric Auger <eric.auger@redhat.com>

---
v2 -> v3:
- pcihp_init and reset are put in ged code instead of machine code
  (Igor)

v1 -> v2:
- Introduce ACPI_PCIHP_REGION_NAME
---
 include/hw/acpi/generic_event_device.h |  4 ++++
 hw/acpi/generic_event_device.c         | 26 ++++++++++++++++++++++++++
 hw/acpi/pcihp.c                        |  1 -
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/include/hw/acpi/generic_event_device.h b/include/hw/acpi/generic_event_device.h
index f5ffa67a39..ec8e1abe0a 100644
--- a/include/hw/acpi/generic_event_device.h
+++ b/include/hw/acpi/generic_event_device.h
@@ -102,6 +102,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(AcpiGedState, ACPI_GED)
 #define ACPI_GED_PWR_DOWN_EVT      0x2
 #define ACPI_GED_NVDIMM_HOTPLUG_EVT 0x4
 #define ACPI_GED_CPU_HOTPLUG_EVT    0x8
+#define ACPI_GED_PCI_HOTPLUG_EVT    0x10
 
 typedef struct GEDState {
     MemoryRegion evt;
@@ -109,6 +110,8 @@ typedef struct GEDState {
     uint32_t     sel;
 } GEDState;
 
+#define ACPI_PCIHP_REGION_NAME "pcihp container"
+
 struct AcpiGedState {
     SysBusDevice parent_obj;
     MemHotplugState memhp_state;
@@ -116,6 +119,7 @@ struct AcpiGedState {
     CPUHotplugState cpuhp_state;
     MemoryRegion container_cpuhp;
     AcpiPciHpState pcihp_state;
+    MemoryRegion container_pcihp;
     GEDState ged_state;
     uint32_t ged_event_bitmap;
     qemu_irq irq;
diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c
index ef1c1ec51f..b4eefb0106 100644
--- a/hw/acpi/generic_event_device.c
+++ b/hw/acpi/generic_event_device.c
@@ -12,6 +12,7 @@
 #include "qemu/osdep.h"
 #include "qapi/error.h"
 #include "hw/acpi/acpi.h"
+#include "hw/acpi/pcihp.h"
 #include "hw/acpi/generic_event_device.h"
 #include "hw/pci/pci.h"
 #include "hw/irq.h"
@@ -27,6 +28,7 @@ static const uint32_t ged_supported_events[] = {
     ACPI_GED_PWR_DOWN_EVT,
     ACPI_GED_NVDIMM_HOTPLUG_EVT,
     ACPI_GED_CPU_HOTPLUG_EVT,
+    ACPI_GED_PCI_HOTPLUG_EVT,
 };
 
 /*
@@ -122,6 +124,12 @@ void build_ged_aml(Aml *table, const char *name, HotplugHandler *hotplug_dev,
                            aml_notify(aml_name("\\_SB.NVDR"),
                                       aml_int(0x80)));
                 break;
+            case ACPI_GED_PCI_HOTPLUG_EVT:
+                aml_append(if_ctx,
+                           aml_acquire(aml_name("\\_SB.PCI0.BLCK"), 0xFFFF));
+                aml_append(if_ctx, aml_call0("\\_SB.PCI0.PCNT"));
+                aml_append(if_ctx, aml_release(aml_name("\\_SB.PCI0.BLCK")));
+                break;
             default:
                 /*
                  * Please make sure all the events in ged_supported_events[]
@@ -300,6 +308,8 @@ static void acpi_ged_send_event(AcpiDeviceIf *adev, AcpiEventStatusBits ev)
         sel = ACPI_GED_NVDIMM_HOTPLUG_EVT;
     } else if (ev & ACPI_CPU_HOTPLUG_STATUS) {
         sel = ACPI_GED_CPU_HOTPLUG_EVT;
+    } else if (ev & ACPI_PCI_HOTPLUG_STATUS) {
+        sel = ACPI_GED_PCI_HOTPLUG_EVT;
     } else {
         /* Unknown event. Return without generating interrupt. */
         warn_report("GED: Unsupported event %d. No irq injected", ev);
@@ -433,6 +443,12 @@ static void acpi_ged_realize(DeviceState *dev, Error **errp)
             cpu_hotplug_hw_init(&s->container_cpuhp, OBJECT(dev),
                                 &s->cpuhp_state, 0);
             break;
+        case ACPI_GED_PCI_HOTPLUG_EVT:
+            memory_region_init(&s->container_pcihp, OBJECT(dev),
+                               ACPI_PCIHP_REGION_NAME, ACPI_PCIHP_SIZE);
+            sysbus_init_mmio(sbd, &s->container_pcihp);
+            acpi_pcihp_init(OBJECT(s), &s->pcihp_state,
+                            s->pcihp_state.root, &s->container_pcihp, 0);
         }
         ged_events--;
     }
@@ -474,6 +490,15 @@ static void acpi_ged_initfn(Object *obj)
     sysbus_init_mmio(sbd, &ged_st->regs);
 }
 
+static void ged_reset(DeviceState *dev)
+{
+    AcpiGedState *s = ACPI_GED(dev);
+
+    if (s->pcihp_state.use_acpi_hotplug_bridge) {
+        acpi_pcihp_reset(&s->pcihp_state);
+    }
+}
+
 static void acpi_ged_class_init(ObjectClass *class, const void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(class);
@@ -488,6 +513,7 @@ static void acpi_ged_class_init(ObjectClass *class, const void *data)
     hc->plug = acpi_ged_device_plug_cb;
     hc->unplug_request = acpi_ged_unplug_request_cb;
     hc->unplug = acpi_ged_unplug_cb;
+    device_class_set_legacy_reset(dc, ged_reset);
 
     adevc->ospm_status = acpi_ged_ospm_status;
     adevc->send_event = acpi_ged_send_event;
diff --git a/hw/acpi/pcihp.c b/hw/acpi/pcihp.c
index e79a24b821..36492aa0d9 100644
--- a/hw/acpi/pcihp.c
+++ b/hw/acpi/pcihp.c
@@ -43,7 +43,6 @@
 #include "qobject/qnum.h"
 #include "trace.h"
 
-#define ACPI_PCIHP_SIZE 0x0018
 #define PCI_UP_BASE 0x0000
 #define PCI_DOWN_BASE 0x0004
 #define PCI_EJ_BASE 0x0008
-- 
2.49.0