[RFC 07/16] RDMA/umem: Preallocate and cache IOVA for UMEM ODP

[Leon Romanovsky]

From: Leon Romanovsky <leonro at nvidia.com>

As a preparation to provide two step interface to map pages,
preallocate IOVA when UMEM is initialized.

Signed-off-by: Leon Romanovsky <leonro at nvidia.com>
---
 drivers/infiniband/core/umem_odp.c | 16 +++++++++++++++-
 include/rdma/ib_umem_odp.h         |  1 +
 include/rdma/ib_verbs.h            | 18 ++++++++++++++++++
 3 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c
index e9fa22d31c23..f69d1233dc82 100644
--- a/drivers/infiniband/core/umem_odp.c
+++ b/drivers/infiniband/core/umem_odp.c
@@ -50,6 +50,7 @@
 static inline int ib_init_umem_odp(struct ib_umem_odp *umem_odp,
 				   const struct mmu_interval_notifier_ops *ops)
 {
+	struct ib_device *dev = umem_odp->umem.ibdev;
 	int ret;
 
 	umem_odp->umem.is_odp = 1;
@@ -87,15 +88,25 @@ static inline int ib_init_umem_odp(struct ib_umem_odp *umem_odp,
 			goto out_pfn_list;
 		}
 
+		umem_odp->iova.dev = dev->dma_device;
+		umem_odp->iova.size = end - start;
+		umem_odp->iova.dir = DMA_BIDIRECTIONAL;
+		ret = ib_dma_alloc_iova(dev, &umem_odp->iova);
+		if (ret)
+			goto out_dma_list;
+
+
 		ret = mmu_interval_notifier_insert(&umem_odp->notifier,
 						   umem_odp->umem.owning_mm,
 						   start, end - start, ops);
 		if (ret)
-			goto out_dma_list;
+			goto out_free_iova;
 	}
 
 	return 0;
 
+out_free_iova:
+	ib_dma_free_iova(dev, &umem_odp->iova);
 out_dma_list:
 	kvfree(umem_odp->dma_list);
 out_pfn_list:
@@ -262,6 +273,8 @@ EXPORT_SYMBOL(ib_umem_odp_get);
 
 void ib_umem_odp_release(struct ib_umem_odp *umem_odp)
 {
+	struct ib_device *dev = umem_odp->umem.ibdev;
+
 	/*
 	 * Ensure that no more pages are mapped in the umem.
 	 *
@@ -274,6 +287,7 @@ void ib_umem_odp_release(struct ib_umem_odp *umem_odp)
 					    ib_umem_end(umem_odp));
 		mutex_unlock(&umem_odp->umem_mutex);
 		mmu_interval_notifier_remove(&umem_odp->notifier);
+		ib_dma_free_iova(dev, &umem_odp->iova);
 		kvfree(umem_odp->dma_list);
 		kvfree(umem_odp->pfn_list);
 	}
diff --git a/include/rdma/ib_umem_odp.h b/include/rdma/ib_umem_odp.h
index 0844c1d05ac6..bb2d7f2a5b04 100644
--- a/include/rdma/ib_umem_odp.h
+++ b/include/rdma/ib_umem_odp.h
@@ -23,6 +23,7 @@ struct ib_umem_odp {
 	 * See ODP_READ_ALLOWED_BIT and ODP_WRITE_ALLOWED_BIT.
 	 */
 	dma_addr_t		*dma_list;
+	struct dma_iova_attrs iova;
 	/*
 	 * The umem_mutex protects the page_list and dma_list fields of an ODP
 	 * umem, allowing only a single thread to map/unmap pages. The mutex
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index b7b6b58dd348..e71fa19187cc 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -4077,6 +4077,24 @@ static inline int ib_dma_mapping_error(struct ib_device *dev, u64 dma_addr)
 	return dma_mapping_error(dev->dma_device, dma_addr);
 }
 
+static inline int ib_dma_alloc_iova(struct ib_device *dev,
+				    struct dma_iova_attrs *iova)
+{
+	if (ib_uses_virt_dma(dev))
+		return 0;
+
+	return dma_alloc_iova(iova);
+}
+
+static inline void ib_dma_free_iova(struct ib_device *dev,
+				    struct dma_iova_attrs *iova)
+{
+	if (ib_uses_virt_dma(dev))
+		return;
+
+	dma_free_iova(iova);
+}
+
 /**
  * ib_dma_map_single - Map a kernel virtual address to DMA address
  * @dev: The device for which the dma_addr is to be created
-- 
2.44.0