x64, x2apic/intr-remap: parse ioapic scope under vt-d structures
Parse the vt-d device scope structures to find the mapping between IO-APICs
and the interrupt remapping hardware units.
This will be used later for enabling Interrupt-remapping for IOAPIC devices.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: akpm@linux-foundation.org
Cc: arjan@linux.intel.com
Cc: andi@firstfloor.org
Cc: ebiederm@xmission.com
Cc: jbarnes@virtuousgeek.org
Cc: steiner@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/drivers/pci/intr_remapping.c b/drivers/pci/intr_remapping.c
new file mode 100644
index 0000000..a80b879
--- /dev/null
+++ b/drivers/pci/intr_remapping.c
@@ -0,0 +1,70 @@
+#include <linux/dmar.h>
+#include <asm/io_apic.h>
+#include "intel-iommu.h"
+#include "intr_remapping.h"
+
+static struct ioapic_scope ir_ioapic[MAX_IO_APICS];
+static int ir_ioapic_num;
+
+static int ir_parse_ioapic_scope(struct acpi_dmar_header *header,
+ struct intel_iommu *iommu)
+{
+ struct acpi_dmar_hardware_unit *drhd;
+ struct acpi_dmar_device_scope *scope;
+ void *start, *end;
+
+ drhd = (struct acpi_dmar_hardware_unit *)header;
+
+ start = (void *)(drhd + 1);
+ end = ((void *)drhd) + header->length;
+
+ while (start < end) {
+ scope = start;
+ if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_IOAPIC) {
+ if (ir_ioapic_num == MAX_IO_APICS) {
+ printk(KERN_WARNING "Exceeded Max IO APICS\n");
+ return -1;
+ }
+
+ printk(KERN_INFO "IOAPIC id %d under DRHD base"
+ " 0x%Lx\n", scope->enumeration_id,
+ drhd->address);
+
+ ir_ioapic[ir_ioapic_num].iommu = iommu;
+ ir_ioapic[ir_ioapic_num].id = scope->enumeration_id;
+ ir_ioapic_num++;
+ }
+ start += scope->length;
+ }
+
+ return 0;
+}
+
+/*
+ * Finds the assocaition between IOAPIC's and its Interrupt-remapping
+ * hardware unit.
+ */
+int __init parse_ioapics_under_ir(void)
+{
+ struct dmar_drhd_unit *drhd;
+ int ir_supported = 0;
+
+ for_each_drhd_unit(drhd) {
+ struct intel_iommu *iommu = drhd->iommu;
+
+ if (ecap_ir_support(iommu->ecap)) {
+ if (ir_parse_ioapic_scope(drhd->hdr, iommu))
+ return -1;
+
+ ir_supported = 1;
+ }
+ }
+
+ if (ir_supported && ir_ioapic_num != nr_ioapics) {
+ printk(KERN_WARNING
+ "Not all IO-APIC's listed under remapping hardware\n");
+ return -1;
+ }
+
+ return ir_supported;
+}
