iommu/amd: Add slab-cache for irq remapping tables

The irq remapping tables for the AMD IOMMU need to be
aligned on a 128 byte boundary. Create a seperate slab-cache
to guarantee this alignment.

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

1 files changed, 23 insertions, 0 deletions

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 6179859..073ed5d 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -36,6 +36,7 @@
 
 #include "amd_iommu_proto.h"
 #include "amd_iommu_types.h"
+#include "irq_remapping.h"
 
 /*
  * definitions for the ACPI scanning code
@@ -127,6 +128,7 @@ struct ivmd_header {
 } __attribute__((packed));
 
 bool amd_iommu_dump;
+bool amd_iommu_irq_remap __read_mostly;
 
 static bool amd_iommu_detected;
 static bool __initdata amd_iommu_disabled;
@@ -1530,6 +1532,11 @@ static struct syscore_ops amd_iommu_syscore_ops = {
 
 static void __init free_on_init_error(void)
 {
+	if (amd_iommu_irq_cache) {
+		kmem_cache_destroy(amd_iommu_irq_cache);
+		amd_iommu_irq_cache = NULL;
+	}
+
 	amd_iommu_uninit_devices();
 
 	free_pages((unsigned long)amd_iommu_pd_alloc_bitmap,
@@ -1669,6 +1676,19 @@ static int __init early_amd_iommu_init(void)
 	if (ret)
 		goto out;
 
+	if (amd_iommu_irq_remap) {
+		/*
+		 * Interrupt remapping enabled, create kmem_cache for the
+		 * remapping tables.
+		 */
+		amd_iommu_irq_cache = kmem_cache_create("irq_remap_cache",
+				MAX_IRQS_PER_TABLE * sizeof(u32),
+				IRQ_TABLE_ALIGNMENT,
+				0, NULL);
+		if (!amd_iommu_irq_cache)
+			goto out;
+	}
+
 	ret = init_memory_definitions(ivrs_base);
 	if (ret)
 		goto out;
@@ -1716,6 +1736,9 @@ static bool detect_ivrs(void)
 	/* Make sure ACS will be enabled during PCI probe */
 	pci_request_acs();
 
+	if (!disable_irq_remap)
+		amd_iommu_irq_remap = true;
+
 	return true;
 }