iommu/vt-d: Add initial support for PASID tables
Add CONFIG_INTEL_IOMMU_SVM, and allocate PASID tables on supported hardware.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
new file mode 100644
index 0000000..5b42a95
--- /dev/null
+++ b/drivers/iommu/intel-svm.c
@@ -0,0 +1,65 @@
+/*
+ * Copyright © 2015 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * Authors: David Woodhouse <dwmw2@infradead.org>
+ */
+
+#include <linux/intel-iommu.h>
+
+int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu)
+{
+ struct page *pages;
+ int order;
+
+ order = ecap_pss(iommu->ecap) + 7 - PAGE_SHIFT;
+ if (order < 0)
+ order = 0;
+
+ pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
+ if (!pages) {
+ pr_warn("IOMMU: %s: Failed to allocate PASID table\n",
+ iommu->name);
+ return -ENOMEM;
+ }
+ iommu->pasid_table = page_address(pages);
+ pr_info("%s: Allocated order %d PASID table.\n", iommu->name, order);
+
+ if (ecap_dis(iommu->ecap)) {
+ pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
+ if (pages)
+ iommu->pasid_state_table = page_address(pages);
+ else
+ pr_warn("IOMMU: %s: Failed to allocate PASID state table\n",
+ iommu->name);
+ }
+
+ return 0;
+}
+
+int intel_svm_free_pasid_tables(struct intel_iommu *iommu)
+{
+ int order;
+
+ order = ecap_pss(iommu->ecap) + 7 - PAGE_SHIFT;
+ if (order < 0)
+ order = 0;
+
+ if (iommu->pasid_table) {
+ free_pages((unsigned long)iommu->pasid_table, order);
+ iommu->pasid_table = NULL;
+ }
+ if (iommu->pasid_state_table) {
+ free_pages((unsigned long)iommu->pasid_state_table, order);
+ iommu->pasid_state_table = NULL;
+ }
+ return 0;
+}