Merge branch 'api-features' into arm/smmu

1 files changed, 140 insertions, 0 deletions

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 6c1b4c900191..a815cf6f6f47 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -48,6 +48,7 @@ struct bus_type;
 struct device;
 struct iommu_domain;
 struct notifier_block;
+struct iommu_sva;
 
 /* iommu fault flags */
 #define IOMMU_FAULT_READ	0x0
@@ -55,6 +56,8 @@ struct notifier_block;
 
 typedef int (*iommu_fault_handler_t)(struct iommu_domain *,
 			struct device *, unsigned long, int, void *);
+typedef int (*iommu_mm_exit_handler_t)(struct device *dev, struct iommu_sva *,
+				       void *);
 
 struct iommu_domain_geometry {
 	dma_addr_t aperture_start; /* First address that can be mapped    */
@@ -156,6 +159,33 @@ struct iommu_resv_region {
 	enum iommu_resv_type	type;
 };
 
+/* Per device IOMMU features */
+enum iommu_dev_features {
+	IOMMU_DEV_FEAT_AUX,	/* Aux-domain feature */
+	IOMMU_DEV_FEAT_SVA,	/* Shared Virtual Addresses */
+};
+
+#define IOMMU_PASID_INVALID	(-1U)
+
+/**
+ * struct iommu_sva_ops - device driver callbacks for an SVA context
+ *
+ * @mm_exit: called when the mm is about to be torn down by exit_mmap. After
+ *           @mm_exit returns, the device must not issue any more transaction
+ *           with the PASID given as argument.
+ *
+ *           The @mm_exit handler is allowed to sleep. Be careful about the
+ *           locks taken in @mm_exit, because they might lead to deadlocks if
+ *           they are also held when dropping references to the mm. Consider the
+ *           following call chain:
+ *           mutex_lock(A); mmput(mm) -> exit_mm() -> @mm_exit() -> mutex_lock(A)
+ *           Using mmput_async() prevents this scenario.
+ *
+ */
+struct iommu_sva_ops {
+	iommu_mm_exit_handler_t mm_exit;
+};
+
 #ifdef CONFIG_IOMMU_API
 
 /**
@@ -186,6 +216,14 @@ struct iommu_resv_region {
  * @of_xlate: add OF master IDs to iommu grouping
  * @is_attach_deferred: Check if domain attach should be deferred from iommu
  *                      driver init to device driver init (default no)
+ * @dev_has/enable/disable_feat: per device entries to check/enable/disable
+ *                               iommu specific features.
+ * @dev_feat_enabled: check enabled feature
+ * @aux_attach/detach_dev: aux-domain specific attach/detach entries.
+ * @aux_get_pasid: get the pasid given an aux-domain
+ * @sva_bind: Bind process address space to device
+ * @sva_unbind: Unbind process address space from device
+ * @sva_get_pasid: Get PASID associated to a SVA handle
  * @pgsize_bitmap: bitmap of all possible supported page sizes
  */
 struct iommu_ops {
@@ -230,6 +268,22 @@ struct iommu_ops {
 	int (*of_xlate)(struct device *dev, struct of_phandle_args *args);
 	bool (*is_attach_deferred)(struct iommu_domain *domain, struct device *dev);
 
+	/* Per device IOMMU features */
+	bool (*dev_has_feat)(struct device *dev, enum iommu_dev_features f);
+	bool (*dev_feat_enabled)(struct device *dev, enum iommu_dev_features f);
+	int (*dev_enable_feat)(struct device *dev, enum iommu_dev_features f);
+	int (*dev_disable_feat)(struct device *dev, enum iommu_dev_features f);
+
+	/* Aux-domain specific attach/detach entries */
+	int (*aux_attach_dev)(struct iommu_domain *domain, struct device *dev);
+	void (*aux_detach_dev)(struct iommu_domain *domain, struct device *dev);
+	int (*aux_get_pasid)(struct iommu_domain *domain, struct device *dev);
+
+	struct iommu_sva *(*sva_bind)(struct device *dev, struct mm_struct *mm,
+				      void *drvdata);
+	void (*sva_unbind)(struct iommu_sva *handle);
+	int (*sva_get_pasid)(struct iommu_sva *handle);
+
 	unsigned long pgsize_bitmap;
 };
 
@@ -400,6 +454,14 @@ struct iommu_fwspec {
 /* ATS is supported */
 #define IOMMU_FWSPEC_PCI_RC_ATS			(1 << 0)
 
+/**
+ * struct iommu_sva - handle to a device-mm bond
+ */
+struct iommu_sva {
+	struct device			*dev;
+	const struct iommu_sva_ops	*ops;
+};
+
 int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode,
 		      const struct iommu_ops *ops);
 void iommu_fwspec_free(struct device *dev);
@@ -420,6 +482,22 @@ static inline void dev_iommu_fwspec_set(struct device *dev,
 int iommu_probe_device(struct device *dev);
 void iommu_release_device(struct device *dev);
 
+bool iommu_dev_has_feature(struct device *dev, enum iommu_dev_features f);
+int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features f);
+int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features f);
+bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features f);
+int iommu_aux_attach_device(struct iommu_domain *domain, struct device *dev);
+void iommu_aux_detach_device(struct iommu_domain *domain, struct device *dev);
+int iommu_aux_get_pasid(struct iommu_domain *domain, struct device *dev);
+
+struct iommu_sva *iommu_sva_bind_device(struct device *dev,
+					struct mm_struct *mm,
+					void *drvdata);
+void iommu_sva_unbind_device(struct iommu_sva *handle);
+int iommu_sva_set_ops(struct iommu_sva *handle,
+		      const struct iommu_sva_ops *ops);
+int iommu_sva_get_pasid(struct iommu_sva *handle);
+
 #else /* CONFIG_IOMMU_API */
 
 struct iommu_ops {};
@@ -704,6 +782,68 @@ const struct iommu_ops *iommu_ops_from_fwnode(struct fwnode_handle *fwnode)
 	return NULL;
 }
 
+static inline bool
+iommu_dev_has_feature(struct device *dev, enum iommu_dev_features feat)
+{
+	return false;
+}
+
+static inline bool
+iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features feat)
+{
+	return false;
+}
+
+static inline int
+iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features feat)
+{
+	return -ENODEV;
+}
+
+static inline int
+iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat)
+{
+	return -ENODEV;
+}
+
+static inline int
+iommu_aux_attach_device(struct iommu_domain *domain, struct device *dev)
+{
+	return -ENODEV;
+}
+
+static inline void
+iommu_aux_detach_device(struct iommu_domain *domain, struct device *dev)
+{
+}
+
+static inline int
+iommu_aux_get_pasid(struct iommu_domain *domain, struct device *dev)
+{
+	return -ENODEV;
+}
+
+static inline struct iommu_sva *
+iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata)
+{
+	return NULL;
+}
+
+static inline void iommu_sva_unbind_device(struct iommu_sva *handle)
+{
+}
+
+static inline int iommu_sva_set_ops(struct iommu_sva *handle,
+				    const struct iommu_sva_ops *ops)
+{
+	return -EINVAL;
+}
+
+static inline int iommu_sva_get_pasid(struct iommu_sva *handle)
+{
+	return IOMMU_PASID_INVALID;
+}
+
 #endif /* CONFIG_IOMMU_API */
 
 #ifdef CONFIG_IOMMU_DEBUGFS