dmar: support for parsing Remapping Hardware Static Affinity structure

Add support for parsing Remapping Hardware Static Affinity (RHSA) structure.
This enables identifying the association between remapping hardware units and
the corresponding proximity domain. This enables to allocate transalation
structures closer to the remapping hardware unit.

Signed-off-by: Suresh Siddha <[e-mail]>
Signed-off-by: David Woodhouse <[e-mail]>

drivers/pci/dmar.c

···
 }
 #endif
 
+static int __init
+dmar_parse_one_rhsa(struct acpi_dmar_header *header)
+{
+	struct acpi_dmar_rhsa *rhsa;
+	struct dmar_drhd_unit *drhd;
+
+	rhsa = (struct acpi_dmar_rhsa *)header;
+	for_each_drhd_unit(drhd)
+		if (drhd->reg_base_addr == rhsa->base_address) {
+			int node = acpi_map_pxm_to_node(rhsa->proximity_domain);
+
+			if (!node_online(node))
+				node = -1;
+			drhd->iommu->node = node;
+		return 0;
+	}
+
+	return -ENODEV;
+}
+
 static void __init
 dmar_table_print_dmar_entry(struct acpi_dmar_header *header)
 {
···
 #endif
 			break;
 		case ACPI_DMAR_HARDWARE_AFFINITY:
-			/* We don't do anything with RHSA (yet?) */
+			ret = dmar_parse_one_rhsa(entry_header);
 			break;
 		default:
 			printk(KERN_WARNING PREFIX
···
 #endif
 	iommu->agaw = agaw;
 	iommu->msagaw = msagaw;
+
+	iommu->node = -1;
 
 	/* the registers might be more than one page */
 	map_size = max_t(int, ecap_max_iotlb_offset(iommu->ecap),

include/linux/intel-iommu.h

···
 #ifdef CONFIG_INTR_REMAP
 	struct ir_table *ir_table;	/* Interrupt remapping info */
 #endif
+	int		node;
 };
 
 static inline void __iommu_flush_cache(