Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@xxxxxxx>
---
drivers/iommu/iommu-sva.c | 34 +++++++++++++++
drivers/iommu/iommu.c | 90 +++++++++++++++++++++++++++++++++++++++
include/linux/iommu.h | 37 ++++++++++++++++
3 files changed, 161 insertions(+)
diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c
index 85ef98efede8..d60d4f0bb89e 100644
--- a/drivers/iommu/iommu-sva.c
+++ b/drivers/iommu/iommu-sva.c
@@ -8,6 +8,38 @@
#include <linux/iommu.h>
#include <linux/slab.h>
+int __iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, int *pasid,
+ unsigned long flags, void *drvdata)
+{
+ return -ENOSYS; /* TODO */
+}
+EXPORT_SYMBOL_GPL(__iommu_sva_bind_device);
+
+int __iommu_sva_unbind_device(struct device *dev, int pasid)
+{
+ return -ENOSYS; /* TODO */
+}
+EXPORT_SYMBOL_GPL(__iommu_sva_unbind_device);
+
+static void __iommu_sva_unbind_device_all(struct device *dev)
+{
+ /* TODO */
+}
+
+/**
+ * iommu_sva_unbind_device_all() - Detach all address spaces from this device
+ * @dev: the device
+ *
+ * When detaching @dev from a domain, IOMMU drivers should use this helper.
+ */
+void iommu_sva_unbind_device_all(struct device *dev)
+{
+ mutex_lock(&dev->iommu_param->sva_lock);
+ __iommu_sva_unbind_device_all(dev);
+ mutex_unlock(&dev->iommu_param->sva_lock);
+}
+EXPORT_SYMBOL_GPL(iommu_sva_unbind_device_all);
+
/**
* iommu_sva_init_device() - Initialize Shared Virtual Addressing for a device
* @dev: the device
@@ -96,6 +128,8 @@ void iommu_sva_shutdown_device(struct device *dev)
if (!param)
goto out_unlock;
+ __iommu_sva_unbind_device_all(dev);
+
if (domain->ops->sva_shutdown_device)
domain->ops->sva_shutdown_device(dev);
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index fa0561ed006f..aba3bf15d46c 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2325,3 +2325,93 @@ int iommu_fwspec_add_ids(struct device *dev, u32 *ids, int num_ids)
return 0;
}
EXPORT_SYMBOL_GPL(iommu_fwspec_add_ids);
+
+/**
+ * iommu_sva_bind_device() - Bind a process address space to a device
+ * @dev: the device
+ * @mm: the mm to bind, caller must hold a reference to it
+ * @pasid: valid address where the PASID will be stored
+ * @flags: bond properties
+ * @drvdata: private data passed to the mm exit handler
+ *
+ * Create a bond between device and task, allowing the device to access the mm
+ * using the returned PASID. If unbind() isn't called first, a subsequent bind()
+ * for the same device and mm fails with -EEXIST.
+ *
+ * iommu_sva_init_device() must be called first, to initialize the required SVA
+ * features. @flags must be a subset of these features.
+ *
+ * The caller must pin down using get_user_pages*() all mappings shared with the
+ * device. mlock() isn't sufficient, as it doesn't prevent minor page faults
+ * (e.g. copy-on-write).
+ *
+ * On success, 0 is returned and @pasid contains a valid ID. Otherwise, an error
+ * is returned.
+ */
+int iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, int *pasid,
+ unsigned long flags, void *drvdata)
+{
+ int ret = -EINVAL;
+ struct iommu_group *group;
+
+ if (!pasid)
+ return -EINVAL;
+
+ group = iommu_group_get(dev);
+ if (!group)
+ return -ENODEV;
+
+ /* Ensure device count and domain don't change while we're binding */
+ mutex_lock(&group->mutex);
+
+ /*
+ * To keep things simple, SVA currently doesn't support IOMMU groups
+ * with more than one device. Existing SVA-capable systems are not
+ * affected by the problems that required IOMMU groups (lack of ACS
+ * isolation, device ID aliasing and other hardware issues).
+ */
+ if (iommu_group_device_count(group) != 1)
+ goto out_unlock;
+
+ ret = __iommu_sva_bind_device(dev, mm, pasid, flags, drvdata);
+
+out_unlock:
+ mutex_unlock(&group->mutex);
+ iommu_group_put(group);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(iommu_sva_bind_device);
+
+/**
+ * iommu_sva_unbind_device() - Remove a bond created with iommu_sva_bind_device
+ * @dev: the device
+ * @pasid: the pasid returned by bind()
+ *
+ * Remove bond between device and address space identified by @pasid. Users
+ * should not call unbind() if the corresponding mm exited (as the PASID might
+ * have been reallocated for another process).
+ *
+ * The device must not be issuing any more transaction for this PASID. All
+ * outstanding page requests for this PASID must have been flushed to the IOMMU.
+ *
+ * Returns 0 on success, or an error value
+ */
+int iommu_sva_unbind_device(struct device *dev, int pasid)
+{
+ int ret = -EINVAL;
+ struct iommu_group *group;
+
+ group = iommu_group_get(dev);
+ if (!group)
+ return -ENODEV;
+
+ mutex_lock(&group->mutex);
+ ret = __iommu_sva_unbind_device(dev, pasid);
+ mutex_unlock(&group->mutex);
+
+ iommu_group_put(group);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(iommu_sva_unbind_device);
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 4c27cb347770..9c49877e37a5 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -586,6 +586,10 @@ void iommu_fwspec_free(struct device *dev);
int iommu_fwspec_add_ids(struct device *dev, u32 *ids, int num_ids);
const struct iommu_ops *iommu_ops_from_fwnode(struct fwnode_handle *fwnode);
+extern int iommu_sva_bind_device(struct device *dev, struct mm_struct *mm,
+ int *pasid, unsigned long flags, void *drvdata);
+extern int iommu_sva_unbind_device(struct device *dev, int pasid);
+
#else /* CONFIG_IOMMU_API */
struct iommu_ops {};
@@ -910,6 +914,18 @@ static inline int iommu_sva_invalidate(struct iommu_domain *domain,
return -ENODEV;
}
+static inline int iommu_sva_bind_device(struct device *dev,
+ struct mm_struct *mm, int *pasid,
+ unsigned long flags, void *drvdata)
+{
+ return -ENODEV;
+}
+
+static inline int iommu_sva_unbind_device(struct device *dev, int pasid)
+{
+ return -ENODEV;
+}
+
#endif /* CONFIG_IOMMU_API */
#ifdef CONFIG_IOMMU_DEBUGFS
@@ -924,6 +940,11 @@ extern int iommu_sva_init_device(struct device *dev, unsigned long features,
unsigned int min_pasid,
unsigned int max_pasid);
extern void iommu_sva_shutdown_device(struct device *dev);
+extern int __iommu_sva_bind_device(struct device *dev, struct mm_struct *mm,
+ int *pasid, unsigned long flags,
+ void *drvdata);
+extern int __iommu_sva_unbind_device(struct device *dev, int pasid);
+extern void iommu_sva_unbind_device_all(struct device *dev);
#else /* CONFIG_IOMMU_SVA */
static inline int iommu_sva_init_device(struct device *dev,
unsigned long features,
@@ -936,6 +957,22 @@ static inline int iommu_sva_init_device(struct device *dev,
static inline void iommu_sva_shutdown_device(struct device *dev)
{
}
+
+static inline int __iommu_sva_bind_device(struct device *dev,
+ struct mm_struct *mm, int *pasid,
+ unsigned long flags, void *drvdata)
+{
+ return -ENODEV;
+}
+
+static inline int __iommu_sva_unbind_device(struct device *dev, int pasid)
+{
+ return -ENODEV;
+}
+
+static inline void iommu_sva_unbind_device_all(struct device *dev)
+{
+}
#endif /* CONFIG_IOMMU_SVA */
#endif /* __LINUX_IOMMU_H */
