x86, irq, ACPI: Implement interface to support ACPI based IOAPIC hot-addition

Implement acpi_register_ioapic() and enhance mp_register_ioapic()
to support ACPI based IOAPIC hot-addition.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1414387308-27148-16-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 29 insertions, 2 deletions

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 2d76f022adc2..0b993511e0c5 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -780,8 +780,35 @@ EXPORT_SYMBOL(acpi_unmap_lsapic);
 
 int acpi_register_ioapic(acpi_handle handle, u64 phys_addr, u32 gsi_base)
 {
-        /* TBD */
-        return -EINVAL;
+        int ret = -ENOSYS;
+#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
+        int ioapic_id;
+        u64 addr;
+        struct ioapic_domain_cfg cfg = {
+                .type = IOAPIC_DOMAIN_DYNAMIC,
+                .ops = &acpi_irqdomain_ops,
+        };
+
+        ioapic_id = acpi_get_ioapic_id(handle, gsi_base, &addr);
+        if (ioapic_id < 0) {
+                unsigned long long uid;
+                acpi_status status;
+
+                status = acpi_evaluate_integer(handle, METHOD_NAME__UID,
+                                               NULL, &uid);
+                if (ACPI_FAILURE(status)) {
+                        acpi_handle_warn(handle, "failed to get IOAPIC ID.\n");
+                        return -EINVAL;
+                }
+                ioapic_id = (int)uid;
+        }
+
+        mutex_lock(&acpi_ioapic_lock);
+        ret  = mp_register_ioapic(ioapic_id, phys_addr, gsi_base, &cfg);
+        mutex_unlock(&acpi_ioapic_lock);
+#endif
+
+        return ret;
 }
 
 EXPORT_SYMBOL(acpi_register_ioapic);