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-rw-r--r--drivers/iommu/intel-svm.c6
-rw-r--r--include/linux/intel-iommu.h1
-rw-r--r--include/linux/intel-svm.h11
3 files changed, 16 insertions, 2 deletions
diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index 006e95dd64ae..89d4d47d0ab3 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -285,11 +285,12 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_
pasid_max = 1 << 20;
mutex_lock(&pasid_mutex);
- if (pasid) {
+ if (pasid && !(flags & SVM_FLAG_PRIVATE_PASID)) {
int i;
idr_for_each_entry(&iommu->pasid_idr, svm, i) {
- if (svm->mm != current->mm)
+ if (svm->mm != current->mm ||
+ (svm->flags & SVM_FLAG_PRIVATE_PASID))
continue;
if (svm->pasid >= pasid_max) {
@@ -355,6 +356,7 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_
svm->pasid = ret;
svm->notifier.ops = &intel_mmuops;
svm->mm = get_task_mm(current);
+ svm->flags = flags;
INIT_LIST_HEAD_RCU(&svm->devs);
ret = -ENOMEM;
if (!svm->mm || (ret = mmu_notifier_register(&svm->notifier, svm->mm))) {
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 57be14fce640..821273ca4873 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -489,6 +489,7 @@ struct intel_svm {
struct mmu_notifier notifier;
struct mm_struct *mm;
struct intel_iommu *iommu;
+ int flags;
int pasid;
struct list_head devs;
};
diff --git a/include/linux/intel-svm.h b/include/linux/intel-svm.h
index 239f8a13a332..dd94ab45a4db 100644
--- a/include/linux/intel-svm.h
+++ b/include/linux/intel-svm.h
@@ -31,6 +31,17 @@ struct svm_dev_ops {
#define SVM_REQ_EXEC (1<<1)
#define SVM_REQ_PRIV (1<<0)
+
+/*
+ * The SVM_FLAG_PRIVATE_PASID flag requests a PASID which is *not* the "main"
+ * PASID for the current process. Even if a PASID already exists, a new one
+ * will be allocated. And the PASID allocated with SVM_FLAG_PRIVATE_PASID
+ * will not be given to subsequent callers. This facility allows a driver to
+ * disambiguate between multiple device contexts which access the same MM,
+ * if there is no other way to do so. It should be used sparingly, if at all.
+ */
+#define SVM_FLAG_PRIVATE_PASID (1<<0)
+
/**
* intel_svm_bind_mm() - Bind the current process to a PASID
* @dev: Device to be granted acccess