[RFC v5 07/17] dma-reserved-iommu: iommu_unmap_reserved

[Eric Auger <eric.auger@linaro.org>]

Introduce a new function whose role is to unmap all allocated
reserved IOVAs and free the reserved iova domain

Signed-off-by: Eric Auger <eric.auger@linaro.org>

---

v3 -> v4:
- previously "iommu/arm-smmu: relinquish reserved resources on
  domain deletion"
---
 drivers/iommu/dma-reserved-iommu.c | 27 ++++++++++++++++++++++++---
 include/linux/dma-reserved-iommu.h |  7 +++++++
 2 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/dma-reserved-iommu.c b/drivers/iommu/dma-reserved-iommu.c
index 537c83e..7217bb7 100644
--- a/drivers/iommu/dma-reserved-iommu.c
+++ b/drivers/iommu/dma-reserved-iommu.c
@@ -116,7 +116,7 @@ unlock:
 }
 EXPORT_SYMBOL_GPL(iommu_alloc_reserved_iova_domain);
 
-void iommu_free_reserved_iova_domain(struct iommu_domain *domain)
+void __iommu_free_reserved_iova_domain(struct iommu_domain *domain)
 {
 	struct iova_domain *iovad =
 		(struct iova_domain *)domain->reserved_iova_cookie;
@@ -124,11 +124,14 @@ void iommu_free_reserved_iova_domain(struct iommu_domain *domain)
 	if (!iovad)
 		return;
 
-	mutex_lock(&domain->reserved_mutex);
-
 	put_iova_domain(iovad);
 	kfree(iovad);
+}
 
+void iommu_free_reserved_iova_domain(struct iommu_domain *domain)
+{
+	mutex_lock(&domain->reserved_mutex);
+	__iommu_free_reserved_iova_domain(domain);
 	mutex_unlock(&domain->reserved_mutex);
 }
 EXPORT_SYMBOL_GPL(iommu_free_reserved_iova_domain);
@@ -245,5 +248,23 @@ unlock:
 }
 EXPORT_SYMBOL_GPL(iommu_put_single_reserved);
 
+void iommu_unmap_reserved(struct iommu_domain *domain)
+{
+	struct rb_node *node;
+
+	mutex_lock(&domain->reserved_mutex);
+	while ((node = rb_first(&domain->reserved_binding_list))) {
+		struct iommu_reserved_binding *b =
+			rb_entry(node, struct iommu_reserved_binding, node);
+
+		while (!kref_put(&b->kref, reserved_binding_release))
+			;
+	}
+	domain->reserved_binding_list = RB_ROOT;
+	__iommu_free_reserved_iova_domain(domain);
+	mutex_unlock(&domain->reserved_mutex);
+}
+EXPORT_SYMBOL_GPL(iommu_unmap_reserved);
+
 
 
diff --git a/include/linux/dma-reserved-iommu.h b/include/linux/dma-reserved-iommu.h
index 71ec800..766c58c 100644
--- a/include/linux/dma-reserved-iommu.h
+++ b/include/linux/dma-reserved-iommu.h
@@ -66,6 +66,13 @@ int iommu_get_single_reserved(struct iommu_domain *domain,
  */
 void iommu_put_single_reserved(struct iommu_domain *domain, dma_addr_t iova);
 
+/**
+ * iommu_unmap_reserved: unmap & destroy the reserved iova bindings
+ *
+ * @domain: iommu domain handle
+ */
+void iommu_unmap_reserved(struct iommu_domain *domain);
+
 #endif	/* CONFIG_IOMMU_DMA_RESERVED */
 #endif	/* __KERNEL__ */
 #endif	/* __DMA_RESERVED_IOMMU_H */
-- 
1.9.1