iommu/amd: Allocate data structures to keep track of irq remapping tables

To easily map device ids to interrupt remapping table
entries a new lookup table is necessary.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

drivers/iommu/amd_iommu_init.c

@@ -183,6 +183,12 @@ u16 *amd_iommu_alias_table;
  */
 struct amd_iommu **amd_iommu_rlookup_table;
 
+/*
+ * This table is used to find the irq remapping table for a given device id
+ * quickly.
+ */
+struct irq_remap_table **irq_lookup_table;
+
 /*
  * AMD IOMMU allows up to 2^16 differend protection domains. This is a bitmap
  * to know which ones are already in use.
@@ -1532,9 +1538,13 @@ static struct syscore_ops amd_iommu_syscore_ops = {
 
 static void __init free_on_init_error(void)
 {
+	free_pages((unsigned long)irq_lookup_table,
+		   get_order(rlookup_table_size));
+
 	if (amd_iommu_irq_cache) {
 		kmem_cache_destroy(amd_iommu_irq_cache);
 		amd_iommu_irq_cache = NULL;
+
 	}
 
 	amd_iommu_uninit_devices();
@@ -1687,6 +1697,12 @@ static int __init early_amd_iommu_init(void)
 				0, NULL);
 		if (!amd_iommu_irq_cache)
 			goto out;
+
+		irq_lookup_table = (void *)__get_free_pages(
+				GFP_KERNEL | __GFP_ZERO,
+				get_order(rlookup_table_size));
+		if (!irq_lookup_table)
+			goto out;
 	}
 
 	ret = init_memory_definitions(ivrs_base);