From 2445d74c465ac0200f6464b24cb5eb76319c1be1 Mon Sep 17 00:00:00 2001 From: Yishai Hadas Date: Tue, 15 Sep 2026 17:09:23 +0300 Subject: [PATCH] RDMA/umem: Support an explicit DMA direction other than DMA_BIDIRECTIONAL Add a dma_dir field to struct ib_umem to record the direction chosen at map time and reuse it at unmap. Thread an explicit dma_data_direction parameter through the internal pinning helpers so each caller can supply the direction that matches the device's actual access pattern. All existing callers still pass DMA_BIDIRECTIONAL, so this is a pure mechanism addition with no behavioural change. Signed-off-by: Yishai Hadas Link: https://patch.msgid.link/20260915140933.40580-6-yishaih@nvidia.com Signed-off-by: Leon Romanovsky --- drivers/infiniband/core/umem.c | 64 ++++++++++++++++++++++------------ include/rdma/ib_umem.h | 2 ++ 2 files changed, 43 insertions(+), 23 deletions(-) diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 88110b9661f5..c2f277ada042 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -55,7 +55,7 @@ static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int d if (dirty) ib_dma_unmap_sgtable_attrs(dev, &umem->sgt_append.sgt, - DMA_BIDIRECTIONAL, umem->dma_attrs); + umem->dma_dir, umem->dma_attrs); for_each_sgtable_sg(&umem->sgt_append.sgt, sg, i) { unpin_user_page_range_dirty_lock(sg_page(sg), @@ -161,7 +161,8 @@ EXPORT_SYMBOL(ib_umem_find_best_pgsz); static struct ib_umem *__ib_umem_get_va(struct ib_device *device, unsigned long addr, size_t size, - int access) + int access, + enum dma_data_direction dir) { struct ib_umem *umem; struct page **page_list; @@ -202,6 +203,7 @@ static struct ib_umem *__ib_umem_get_va(struct ib_device *device, */ umem->iova = addr; umem->writable = ib_access_writable(access); + umem->dma_dir = dir; umem->owning_mm = mm = current->mm; umem->dma_attrs = DMA_ATTR_REQUIRE_COHERENT; if (access & IB_ACCESS_RELAXED_ORDERING) @@ -261,7 +263,7 @@ static struct ib_umem *__ib_umem_get_va(struct ib_device *device, } ret = ib_dma_map_sgtable_attrs(device, &umem->sgt_append.sgt, - DMA_BIDIRECTIONAL, umem->dma_attrs); + dir, umem->dma_attrs); if (ret) goto umem_release; goto out; @@ -279,17 +281,16 @@ static struct ib_umem *__ib_umem_get_va(struct ib_device *device, return ret ? ERR_PTR(ret) : umem; } -/** - * ib_umem_get_desc - Pin a umem from a buffer descriptor. - * @device: IB device. - * @desc: buffer descriptor (VA or DMABUF). - * @access: IB access flags. +/* + * __ib_umem_get_desc_dir - core implementation for ib_umem_get_desc(). * - * Return: caller-owned umem on success, ERR_PTR(...) on error. + * @dir applies to VA buffers only; dmabuf direction is managed by the + * dmabuf subsystem and this argument is ignored for that type. */ -struct ib_umem *ib_umem_get_desc(struct ib_device *device, - const struct ib_uverbs_buffer_desc *desc, - int access) +static struct ib_umem * +__ib_umem_get_desc_dir(struct ib_device *device, + const struct ib_uverbs_buffer_desc *desc, + int access, enum dma_data_direction dir) { struct ib_umem_dmabuf *umem_dmabuf; @@ -310,11 +311,26 @@ struct ib_umem *ib_umem_get_desc(struct ib_device *device, return &umem_dmabuf->umem; case IB_UVERBS_BUFFER_TYPE_VA: return __ib_umem_get_va(device, desc->addr, desc->length, - access); + access, dir); default: return ERR_PTR(-EINVAL); } } + +/** + * ib_umem_get_desc - Pin a umem from a buffer descriptor. + * @device: IB device. + * @desc: buffer descriptor (VA or DMABUF). + * @access: IB access flags. + * + * Return: caller-owned umem on success, ERR_PTR(...) on error. + */ +struct ib_umem *ib_umem_get_desc(struct ib_device *device, + const struct ib_uverbs_buffer_desc *desc, + int access) +{ + return __ib_umem_get_desc_dir(device, desc, access, DMA_BIDIRECTIONAL); +} EXPORT_SYMBOL(ib_umem_get_desc); /* @@ -376,11 +392,12 @@ static int ib_umem_resolve_desc(const struct uverbs_attr_bundle *attrs, static struct ib_umem * ib_umem_get_desc_check(struct ib_device *device, const struct ib_uverbs_buffer_desc *desc, - size_t min_size, int access) + size_t min_size, int access, + enum dma_data_direction dir) { struct ib_umem *umem; - umem = ib_umem_get_desc(device, desc, access); + umem = __ib_umem_get_desc_dir(device, desc, access, dir); if (IS_ERR(umem)) return umem; if (umem->length < min_size) { @@ -401,7 +418,7 @@ static struct ib_umem * ib_umem_get_from_attrs(struct ib_device *device, const struct uverbs_attr_bundle *attrs, u16 attr_id, ib_umem_buf_desc_filler_t legacy_filler, - size_t size, int access) + size_t size, int access, enum dma_data_direction dir) { struct ib_uverbs_buffer_desc desc = {}; int ret; @@ -411,7 +428,7 @@ ib_umem_get_from_attrs(struct ib_device *device, return NULL; if (ret) return ERR_PTR(ret); - return ib_umem_get_desc_check(device, &desc, size, access); + return ib_umem_get_desc_check(device, &desc, size, access, dir); } /* @@ -431,7 +448,8 @@ ib_umem_get_from_attrs_or_va(struct ib_device *device, const struct uverbs_attr_bundle *attrs, u16 attr_id, ib_umem_buf_desc_filler_t legacy_filler, - u64 addr, size_t size, int access) + u64 addr, size_t size, int access, + enum dma_data_direction dir) { struct ib_uverbs_buffer_desc desc = {}; int ret; @@ -445,7 +463,7 @@ ib_umem_get_from_attrs_or_va(struct ib_device *device, }; else if (ret) return ERR_PTR(ret); - return ib_umem_get_desc_check(device, &desc, size, access); + return ib_umem_get_desc_check(device, &desc, size, access, dir); } /** @@ -464,7 +482,7 @@ struct ib_umem *ib_umem_get_attr(struct ib_device *device, u16 attr_id, size_t size, int access) { return ib_umem_get_from_attrs(device, attrs, attr_id, NULL, size, - access); + access, DMA_BIDIRECTIONAL); } EXPORT_SYMBOL(ib_umem_get_attr); @@ -503,7 +521,7 @@ struct ib_umem *ib_umem_get_attr_or_va(struct ib_device *device, int access) { return ib_umem_get_from_attrs_or_va(device, attrs, attr_id, NULL, addr, - size, access); + size, access, DMA_BIDIRECTIONAL); } EXPORT_SYMBOL(ib_umem_get_attr_or_va); @@ -579,7 +597,7 @@ struct ib_umem *ib_umem_get_cq_buf(struct ib_device *device, return ib_umem_get_from_attrs(device, attrs, UVERBS_ATTR_CREATE_CQ_BUF_UMEM, uverbs_create_cq_get_buffer_desc, - size, access); + size, access, DMA_BIDIRECTIONAL); } EXPORT_SYMBOL(ib_umem_get_cq_buf); @@ -608,7 +626,7 @@ struct ib_umem *ib_umem_get_cq_buf_or_va(struct ib_device *device, return ib_umem_get_from_attrs_or_va(device, attrs, UVERBS_ATTR_CREATE_CQ_BUF_UMEM, uverbs_create_cq_get_buffer_desc, - addr, size, access); + addr, size, access, DMA_BIDIRECTIONAL); } EXPORT_SYMBOL(ib_umem_get_cq_buf_or_va); diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h index 1fe87fd1d769..dcb645419692 100644 --- a/include/rdma/ib_umem.h +++ b/include/rdma/ib_umem.h @@ -7,6 +7,7 @@ #ifndef IB_UMEM_H #define IB_UMEM_H +#include #include struct ib_device; @@ -19,6 +20,7 @@ struct ib_umem { size_t length; unsigned long address; unsigned long dma_attrs; + enum dma_data_direction dma_dir; u32 writable : 1; u32 is_odp : 1; u32 is_dmabuf : 1;