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

Leon Romanovsky
2024-03-05T13:33:35Z

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

Signed-off-by: Leon Romanovsky <leonro@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