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/Makefile b/drivers/pci/Makefile
index 4d1ce2e..1c409c7 100644 (file)
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -26,6 +26,8 @@ obj-$(CONFIG_HT_IRQ) += htirq.o
 # Build Intel IOMMU support
 obj-$(CONFIG_DMAR) += dmar.o iova.o intel-iommu.o
 
+obj-$(CONFIG_INTR_REMAP) += dmar.o intr_remapping.o
+
 #
 # Some architectures use the generic PCI setup functions
 #

diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c
index 903f170..127764c 100644 (file)
--- a/drivers/pci/dmar.c
+++ b/drivers/pci/dmar.c
@@ -423,6 +423,9 @@ int __init dmar_table_init(void)
                printk(KERN_INFO PREFIX "No RMRR found\n");
 #endif
 
+#ifdef CONFIG_INTR_REMAP
+       parse_ioapics_under_ir();
+#endif
        return 0;
 }
 

diff --git a/drivers/pci/intel-iommu.h b/drivers/pci/intel-iommu.h
index 371e3b9..eb167e3 100644 (file)
--- a/drivers/pci/intel-iommu.h
+++ b/drivers/pci/intel-iommu.h
@@ -114,6 +114,8 @@ static inline void dmar_writeq(void __iomem *addr, u64 val)
 #define ecap_max_iotlb_offset(e) \
        (ecap_iotlb_offset(e) + ecap_niotlb_iunits(e) * 16)
 #define ecap_coherent(e)       ((e) & 0x1)
+#define ecap_eim_support(e)    ((e >> 4) & 0x1)
+#define ecap_ir_support(e)     ((e >> 3) & 0x1)
 
 
 /* IOTLB_REG */

diff --git a/drivers/pci/intr_remapping.c b/drivers/pci/intr_remapping.c
new file mode 100644 (file)
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;
+}

diff --git a/drivers/pci/intr_remapping.h b/drivers/pci/intr_remapping.h
new file mode 100644 (file)
index 0000000..c4a40b2
--- /dev/null
+++ b/drivers/pci/intr_remapping.h
@@ -0,0 +1,6 @@
+#include "intel-iommu.h"
+
+struct ioapic_scope {
+       struct intel_iommu *iommu;
+       unsigned int id;
+};

diff --git a/include/linux/dmar.h b/include/linux/dmar.h
index 3ab07e4..c4e96eb 100644 (file)
--- a/include/linux/dmar.h
+++ b/include/linux/dmar.h
@@ -47,6 +47,7 @@ extern int intel_iommu_init(void);
 extern int dmar_table_init(void);
 extern int early_dmar_detect(void);
 extern int dmar_dev_scope_init(void);
+extern int parse_ioapics_under_ir(void);
 
 extern struct list_head dmar_drhd_units;
 extern struct list_head dmar_rmrr_units;