Commit 1e4df4a2 authored by Gal Pressman's avatar Gal Pressman Committed by Jason Gunthorpe
Browse files

RDMA/umem: Allow pinned dmabuf umem usage 

Introduce ib_umem_dmabuf_get_pinned() which allows the driver to get a
dmabuf umem which is pinned and does not require move_notify callback
implementation.

The returned umem is pinned and DMA mapped like standard cpu umems, and is
released through ib_umem_release() (incl. unpinning and unmapping).

Link: https://lore.kernel.org/r/20211012120903.96933-3-galpress@amazon.com


Signed-off-by: default avatarGal Pressman <galpress@amazon.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent 5460601d

drivers/infiniband/core/umem_dmabuf.c

+51 −0
Original line number Diff line number Diff line
@@ -163,12 +163,63 @@ struct ib_umem_dmabuf *ib_umem_dmabuf_get(struct ib_device *device, 
}

EXPORT_SYMBOL(ib_umem_dmabuf_get);



static void

ib_umem_dmabuf_unsupported_move_notify(struct dma_buf_attachment *attach)

{

	struct ib_umem_dmabuf *umem_dmabuf = attach->importer_priv;



	ibdev_warn_ratelimited(umem_dmabuf->umem.ibdev,

			       "Invalidate callback should not be called when memory is pinned\n");

}



static struct dma_buf_attach_ops ib_umem_dmabuf_attach_pinned_ops = {

	.allow_peer2peer = true,

	.move_notify = ib_umem_dmabuf_unsupported_move_notify,

};



struct ib_umem_dmabuf *ib_umem_dmabuf_get_pinned(struct ib_device *device,

						 unsigned long offset,

						 size_t size, int fd,

						 int access)

{

	struct ib_umem_dmabuf *umem_dmabuf;

	int err;



	umem_dmabuf = ib_umem_dmabuf_get(device, offset, size, fd, access,

					 &ib_umem_dmabuf_attach_pinned_ops);

	if (IS_ERR(umem_dmabuf))

		return umem_dmabuf;



	dma_resv_lock(umem_dmabuf->attach->dmabuf->resv, NULL);

	err = dma_buf_pin(umem_dmabuf->attach);

	if (err)

		goto err_release;

	umem_dmabuf->pinned = 1;



	err = ib_umem_dmabuf_map_pages(umem_dmabuf);

	if (err)

		goto err_unpin;

	dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv);



	return umem_dmabuf;



err_unpin:

	dma_buf_unpin(umem_dmabuf->attach);

err_release:

	dma_resv_unlock(umem_dmabuf->attach->dmabuf->resv);

	ib_umem_release(&umem_dmabuf->umem);

	return ERR_PTR(err);

}

EXPORT_SYMBOL(ib_umem_dmabuf_get_pinned);



void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf)

{

	struct dma_buf *dmabuf = umem_dmabuf->attach->dmabuf;



	dma_resv_lock(dmabuf->resv, NULL);

	ib_umem_dmabuf_unmap_pages(umem_dmabuf);

	if (umem_dmabuf->pinned)

		dma_buf_unpin(umem_dmabuf->attach);

	dma_resv_unlock(dmabuf->resv);



	dma_buf_detach(dmabuf, umem_dmabuf->attach);

include/rdma/ib_umem.h

+11 −0
Original line number Diff line number Diff line
@@ -38,6 +38,7 @@ struct ib_umem_dmabuf { 
	unsigned long first_sg_offset;

	unsigned long last_sg_trim;

	void *private;

	u8 pinned : 1;

};



static inline struct ib_umem_dmabuf *to_ib_umem_dmabuf(struct ib_umem *umem)
@@ -139,6 +140,10 @@ struct ib_umem_dmabuf *ib_umem_dmabuf_get(struct ib_device *device, 
					  unsigned long offset, size_t size,

					  int fd, int access,

					  const struct dma_buf_attach_ops *ops);

struct ib_umem_dmabuf *ib_umem_dmabuf_get_pinned(struct ib_device *device,

						 unsigned long offset,

						 size_t size, int fd,

						 int access);

int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf);

void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf);

void ib_umem_dmabuf_release(struct ib_umem_dmabuf *umem_dmabuf);
@@ -179,6 +184,12 @@ struct ib_umem_dmabuf *ib_umem_dmabuf_get(struct ib_device *device, 
{

	return ERR_PTR(-EOPNOTSUPP);

}

static inline struct ib_umem_dmabuf *

ib_umem_dmabuf_get_pinned(struct ib_device *device, unsigned long offset,

			  size_t size, int fd, int access)

{

	return ERR_PTR(-EOPNOTSUPP);

}

static inline int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf)

{

	return -EOPNOTSUPP;