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RDMA/umem: Support an explicit DMA direction other than DMA_BIDIRECTIONAL

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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 <yishaih@nvidia.com>
Link: https://patch.msgid.link/20260915140933.40580-6-yishaih@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
This commit is contained in:
Yishai Hadas 2026-09-15 17:09:23 +03:00 committed by Leon Romanovsky
parent b577999f6f
commit 2445d74c46
2 changed files with 43 additions and 23 deletions
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64
drivers/infiniband/core/umem.c
View File

@ -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);

2
include/rdma/ib_umem.h
View File

@ -7,6 +7,7 @@
#ifndef IB_UMEM_H
#define IB_UMEM_H
#include <linux/dma-direction.h>
#include <linux/scatterlist.h>
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;