4 files changed, 95 insertions, 1 deletions

diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 1fb695854809..0a190b4b2ada 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -14,7 +14,7 @@ obj-$(CONFIG_AMD_IOMMU_V2) += amd_iommu_v2.o
 obj-$(CONFIG_ARM_SMMU) += arm-smmu.o
 obj-$(CONFIG_ARM_SMMU_V3) += arm-smmu-v3.o
 obj-$(CONFIG_DMAR_TABLE) += dmar.o
-obj-$(CONFIG_INTEL_IOMMU) += intel-iommu.o
+obj-$(CONFIG_INTEL_IOMMU) += intel-iommu.o intel-pasid.o
 obj-$(CONFIG_INTEL_IOMMU_SVM) += intel-svm.o
 obj-$(CONFIG_IPMMU_VMSA) += ipmmu-vmsa.o
 obj-$(CONFIG_IRQ_REMAP) += intel_irq_remapping.o irq_remapping.o
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 497ef94c5a8c..fa15ed036ddc 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -53,6 +53,7 @@
 #include <asm/iommu.h>
 
 #include "irq_remapping.h"
+#include "intel-pasid.h"
 
 #define ROOT_SIZE               VTD_PAGE_SIZE
 #define CONTEXT_SIZE            VTD_PAGE_SIZE
@@ -3293,6 +3294,18 @@ static int __init init_dmars(void)
         }
 
         for_each_active_iommu(iommu, drhd) {
+                /*
+                 * Find the max pasid size of all IOMMU's in the system.
+                 * We need to ensure the system pasid table is no bigger
+                 * than the smallest supported.
+                 */
+                if (pasid_enabled(iommu)) {
+                        u32 temp = 2 << ecap_pss(iommu->ecap);
+
+                        intel_pasid_max_id = min_t(u32, temp,
+                                                   intel_pasid_max_id);
+                }
+
                 g_iommus[iommu->seq_id] = iommu;
 
                 intel_iommu_init_qi(iommu);
diff --git a/drivers/iommu/intel-pasid.c b/drivers/iommu/intel-pasid.c
new file mode 100644
index 000000000000..e918fe01ce7f
--- /dev/null
+++ b/drivers/iommu/intel-pasid.c
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * intel-pasid.c - PASID idr, table and entry manipulation
+ *
+ * Copyright (C) 2018 Intel Corporation
+ *
+ * Author: Lu Baolu <baolu.lu@linux.intel.com>
+ */
+
+#define pr_fmt(fmt)     "DMAR: " fmt
+
+#include <linux/dmar.h>
+#include <linux/intel-iommu.h>
+#include <linux/iommu.h>
+#include <linux/memory.h>
+#include <linux/spinlock.h>
+
+#include "intel-pasid.h"
+
+/*
+ * Intel IOMMU system wide PASID name space:
+ */
+static DEFINE_SPINLOCK(pasid_lock);
+u32 intel_pasid_max_id = PASID_MAX;
+static DEFINE_IDR(pasid_idr);
+
+int intel_pasid_alloc_id(void *ptr, int start, int end, gfp_t gfp)
+{
+        int ret, min, max;
+
+        min = max_t(int, start, PASID_MIN);
+        max = min_t(int, end, intel_pasid_max_id);
+
+        WARN_ON(in_interrupt());
+        idr_preload(gfp);
+        spin_lock(&pasid_lock);
+        ret = idr_alloc(&pasid_idr, ptr, min, max, GFP_ATOMIC);
+        spin_unlock(&pasid_lock);
+        idr_preload_end();
+
+        return ret;
+}
+
+void intel_pasid_free_id(int pasid)
+{
+        spin_lock(&pasid_lock);
+        idr_remove(&pasid_idr, pasid);
+        spin_unlock(&pasid_lock);
+}
+
+void *intel_pasid_lookup_id(int pasid)
+{
+        void *p;
+
+        spin_lock(&pasid_lock);
+        p = idr_find(&pasid_idr, pasid);
+        spin_unlock(&pasid_lock);
+
+        return p;
+}
diff --git a/drivers/iommu/intel-pasid.h b/drivers/iommu/intel-pasid.h
new file mode 100644
index 000000000000..b1c5296290e5
--- /dev/null
+++ b/drivers/iommu/intel-pasid.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * intel-pasid.h - PASID idr, table and entry header
+ *
+ * Copyright (C) 2018 Intel Corporation
+ *
+ * Author: Lu Baolu <baolu.lu@linux.intel.com>
+ */
+
+#ifndef __INTEL_PASID_H
+#define __INTEL_PASID_H
+
+#define PASID_MIN                       0x1
+#define PASID_MAX                       0x100000
+
+extern u32 intel_pasid_max_id;
+int intel_pasid_alloc_id(void *ptr, int start, int end, gfp_t gfp);
+void intel_pasid_free_id(int pasid);
+void *intel_pasid_lookup_id(int pasid);
+
+#endif /* __INTEL_PASID_H */