Re: [PATCH v2 2/2] RDMA/rw: map P2P memory correctly for signature operations

[Max Gurtovoy <maxg@xxxxxxxxxxxx>]

On 2/20/2020 6:51 PM, Logan Gunthorpe wrote:
> On 2020-02-20 3:08 a.m., Max Gurtovoy wrote:
> > Since RDMA rw API support operations with P2P memory sg list, make sure
> > to map/unmap the scatter list for signature operation correctly.
> Does anyone actually use P2P pages with rdma_rw_ctx_signature_init()?

We're adding support for NVMf/target in these days.

Nevertheless, the RW API defined as an API that might use P2P pages.

> Logan
>
> > Signed-off-by: Max Gurtovoy <maxg@xxxxxxxxxxxx>
> > ---
> >   drivers/infiniband/core/rw.c | 12 ++++++------
> >   1 file changed, 6 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/infiniband/core/rw.c b/drivers/infiniband/core/rw.c
> > index 69513b484507..6eba8453f206 100644
> > --- a/drivers/infiniband/core/rw.c
> > +++ b/drivers/infiniband/core/rw.c
> > @@ -392,13 +392,13 @@ int rdma_rw_ctx_signature_init(struct rdma_rw_ctx *ctx, struct ib_qp *qp,
> >   		return -EINVAL;
> >   	}
> >   
> > -	ret = ib_dma_map_sg(dev, sg, sg_cnt, dir);
> > +	ret = rdma_rw_map_sg(dev, sg, sg_cnt, dir);
> >   	if (!ret)
> >   		return -ENOMEM;
> >   	sg_cnt = ret;
> >   
> >   	if (prot_sg_cnt) {
> > -		ret = ib_dma_map_sg(dev, prot_sg, prot_sg_cnt, dir);
> > +		ret = rdma_rw_map_sg(dev, prot_sg, prot_sg_cnt, dir);
> >   		if (!ret) {
> >   			ret = -ENOMEM;
> >   			goto out_unmap_sg;
> > @@ -467,9 +467,9 @@ int rdma_rw_ctx_signature_init(struct rdma_rw_ctx *ctx, struct ib_qp *qp,
> >   	kfree(ctx->reg);
> >   out_unmap_prot_sg:
> >   	if (prot_sg_cnt)
> > -		ib_dma_unmap_sg(dev, prot_sg, prot_sg_cnt, dir);
> > +		rdma_rw_unmap_sg(dev, prot_sg, prot_sg_cnt, dir);
> >   out_unmap_sg:
> > -	ib_dma_unmap_sg(dev, sg, sg_cnt, dir);
> > +	rdma_rw_unmap_sg(dev, sg, sg_cnt, dir);
> >   	return ret;
> >   }
> >   EXPORT_SYMBOL(rdma_rw_ctx_signature_init);
> > @@ -629,9 +629,9 @@ void rdma_rw_ctx_destroy_signature(struct rdma_rw_ctx *ctx, struct ib_qp *qp,
> >   	ib_mr_pool_put(qp, &qp->sig_mrs, ctx->reg->mr);
> >   	kfree(ctx->reg);
> >   
> > -	ib_dma_unmap_sg(qp->pd->device, sg, sg_cnt, dir);
> >   	if (prot_sg_cnt)
> > -		ib_dma_unmap_sg(qp->pd->device, prot_sg, prot_sg_cnt, dir);
> > +		rdma_rw_unmap_sg(qp->pd->device, prot_sg, prot_sg_cnt, dir);
> > +	rdma_rw_unmap_sg(qp->pd->device, sg, sg_cnt, dir);
> >   }
> >   EXPORT_SYMBOL(rdma_rw_ctx_destroy_signature);
> >