[PATCH] ACPI based I/O APIC hot-plug: acpiphp support

This patch adds PCI based I/O xAPIC hot-add support to ACPIPHP
driver. When PCI root bridge is hot-added, all PCI based I/O xAPICs
under the root bridge are hot-added by this patch. Hot-remove support
is TBD.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 129 insertions, 0 deletions

diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index b4a921236252..424e7de181ae 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -552,6 +552,132 @@ static void remove_bridge(acpi_handle handle)
         }
 }
 
+static struct pci_dev * get_apic_pci_info(acpi_handle handle)
+{
+        struct acpi_pci_id id;
+        struct pci_bus *bus;
+        struct pci_dev *dev;
+
+        if (ACPI_FAILURE(acpi_get_pci_id(handle, &id)))
+                return NULL;
+
+        bus = pci_find_bus(id.segment, id.bus);
+        if (!bus)
+                return NULL;
+
+        dev = pci_get_slot(bus, PCI_DEVFN(id.device, id.function));
+        if (!dev)
+                return NULL;
+
+        if ((dev->class != PCI_CLASS_SYSTEM_PIC_IOAPIC) &&
+            (dev->class != PCI_CLASS_SYSTEM_PIC_IOXAPIC))
+        {
+                pci_dev_put(dev);
+                return NULL;
+        }
+
+        return dev;
+}
+
+static int get_gsi_base(acpi_handle handle, u32 *gsi_base)
+{
+        acpi_status status;
+        int result = -1;
+        unsigned long gsb;
+        struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
+        union acpi_object *obj;
+        void *table;
+
+        status = acpi_evaluate_integer(handle, "_GSB", NULL, &gsb);
+        if (ACPI_SUCCESS(status)) {
+                *gsi_base = (u32)gsb;
+                return 0;
+        }
+
+        status = acpi_evaluate_object(handle, "_MAT", NULL, &buffer);
+        if (ACPI_FAILURE(status) || !buffer.length || !buffer.pointer)
+                return -1;
+
+        obj = buffer.pointer;
+        if (obj->type != ACPI_TYPE_BUFFER)
+                goto out;
+
+        table = obj->buffer.pointer;
+        switch (((acpi_table_entry_header *)table)->type) {
+        case ACPI_MADT_IOSAPIC:
+                *gsi_base = ((struct acpi_table_iosapic *)table)->global_irq_base;
+                result = 0;
+                break;
+        case ACPI_MADT_IOAPIC:
+                *gsi_base = ((struct acpi_table_ioapic *)table)->global_irq_base;
+                result = 0;
+                break;
+        default:
+                break;
+        }
+ out:
+        acpi_os_free(buffer.pointer);
+        return result;
+}
+
+static acpi_status
+ioapic_add(acpi_handle handle, u32 lvl, void *context, void **rv)
+{
+        acpi_status status;
+        unsigned long sta;
+        acpi_handle tmp;
+        struct pci_dev *pdev;
+        u32 gsi_base;
+        u64 phys_addr;
+
+        /* Evaluate _STA if present */
+        status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
+        if (ACPI_SUCCESS(status) && sta != ACPI_STA_ALL)
+                return AE_CTRL_DEPTH;
+
+        /* Scan only PCI bus scope */
+        status = acpi_get_handle(handle, "_HID", &tmp);
+        if (ACPI_SUCCESS(status))
+                return AE_CTRL_DEPTH;
+
+        if (get_gsi_base(handle, &gsi_base))
+                return AE_OK;
+
+        pdev = get_apic_pci_info(handle);
+        if (!pdev)
+                return AE_OK;
+
+        if (pci_enable_device(pdev)) {
+                pci_dev_put(pdev);
+                return AE_OK;
+        }
+
+        pci_set_master(pdev);
+
+        if (pci_request_region(pdev, 0, "I/O APIC(acpiphp)")) {
+                pci_disable_device(pdev);
+                pci_dev_put(pdev);
+                return AE_OK;
+        }
+
+        phys_addr = pci_resource_start(pdev, 0);
+        if (acpi_register_ioapic(handle, phys_addr, gsi_base)) {
+                pci_release_region(pdev, 0);
+                pci_disable_device(pdev);
+                pci_dev_put(pdev);
+                return AE_OK;
+        }
+
+        return AE_OK;
+}
+
+static int acpiphp_configure_ioapics(acpi_handle handle)
+{
+        acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
+                            ACPI_UINT32_MAX, ioapic_add, NULL, NULL);
+        return 0;
+}
+
 static int power_on_slot(struct acpiphp_slot *slot)
 {
         acpi_status status;
@@ -942,6 +1068,7 @@ static int acpiphp_configure_bridge (acpi_handle handle)
         acpiphp_sanitize_bus(bus);
         acpiphp_set_hpp_values(handle, bus);
         pci_enable_bridges(bus);
+        acpiphp_configure_ioapics(handle);
         return 0;
 }
 
diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
index bf608808a60c..810bbbcee404 100644
--- a/include/linux/pci_ids.h
+++ b/include/linux/pci_ids.h
@@ -62,6 +62,8 @@
 
 #define PCI_BASE_CLASS_SYSTEM           0x08
 #define PCI_CLASS_SYSTEM_PIC            0x0800
+#define PCI_CLASS_SYSTEM_PIC_IOAPIC     0x080010
+#define PCI_CLASS_SYSTEM_PIC_IOXAPIC    0x080020
 #define PCI_CLASS_SYSTEM_DMA            0x0801
 #define PCI_CLASS_SYSTEM_TIMER          0x0802
 #define PCI_CLASS_SYSTEM_RTC            0x0803