pcihp: generalization of piix4 acpi

Add ACPI based PCI hotplug library with bridge hotplug
support.
Design
   - each bus gets assigned "bsel" property.
   - ACPI code writes this number
     to a new BNUM register, then uses existing
     UP/DOWN registers to probe slot status;
     to eject, write number to BNUM register,
     then slot into existing EJ.

The interface is actually backwards-compatible with
existing PIIX4 ACPI (though not migration compatible).

This is split out from PIIX4 codebase so we can
reuse it for Q35 as well.

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

1 files changed, 72 insertions, 0 deletions

diff --git a/include/hw/acpi/pcihp.h b/include/hw/acpi/pcihp.h
new file mode 100644
index 0000000000..6230e60954
--- /dev/null
+++ b/include/hw/acpi/pcihp.h
@@ -0,0 +1,72 @@
+/*
+ * QEMU<->ACPI BIOS PCI hotplug interface
+ *
+ * QEMU supports PCI hotplug via ACPI. This module
+ * implements the interface between QEMU and the ACPI BIOS.
+ * Interface specification - see docs/specs/acpi_pci_hotplug.txt
+ *
+ * Copyright (c) 2013, Red Hat Inc, Michael S. Tsirkin (mst@redhat.com)
+ * Copyright (c) 2006 Fabrice Bellard
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2 as published by the Free Software Foundation.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>
+ *
+ * Contributions after 2012-01-13 are licensed under the terms of the
+ * GNU GPL, version 2 or (at your option) any later version.
+ */
+
+#ifndef HW_ACPI_PCIHP_H
+#define HW_ACPI_PCIHP_H
+
+#include <inttypes.h>
+#include <qemu/typedefs.h>
+#include "hw/pci/pci.h" /* for PCIHotplugState */
+
+typedef struct AcpiPciHpPciStatus {
+    uint32_t up; /* deprecated, maintained for migration compatibility */
+    uint32_t down;
+    uint32_t hotplug_enable;
+    uint32_t device_present;
+} AcpiPciHpPciStatus;
+
+#define ACPI_PCIHP_PROP_BSEL "acpi-pcihp-bsel"
+#define ACPI_PCIHP_MAX_HOTPLUG_BUS 256
+
+typedef struct AcpiPciHpState {
+    AcpiPciHpPciStatus acpi_pcihp_pci_status[ACPI_PCIHP_MAX_HOTPLUG_BUS];
+    uint32_t hotplug_select;
+    PCIBus *root;
+    MemoryRegion io;
+} AcpiPciHpState;
+
+void acpi_pcihp_init(AcpiPciHpState *, PCIBus *root,
+                     MemoryRegion *address_space_io);
+
+/* Invoke on device hotplug */
+int acpi_pcihp_device_hotplug(AcpiPciHpState *, PCIDevice *,
+                              PCIHotplugState state);
+
+/* Called on reset */
+void acpi_pcihp_reset(AcpiPciHpState *s);
+
+extern const VMStateDescription vmstate_acpi_pcihp_pci_status;
+
+#define VMSTATE_PCI_HOTPLUG(pcihp, state, test_pcihp) \
+        VMSTATE_UINT32_TEST(pcihp.hotplug_select, state, \
+                            test_pcihp), \
+        VMSTATE_STRUCT_ARRAY_TEST(pcihp.acpi_pcihp_pci_status, state, \
+                                  ACPI_PCIHP_MAX_HOTPLUG_BUS, \
+                                  test_pcihp, 1, \
+                                  vmstate_acpi_pcihp_pci_status, \
+                                  AcpiPciHpPciStatus)
+
+#endif