Re: [PATCH rdma-next 2/2] RDMA: Use dma_map_sgtable for map umem pages

[Leon Romanovsky <leon@kernel.org>]

On Tue, Jun 22, 2021 at 10:18:16AM -0300, Jason Gunthorpe wrote:
> On Tue, Jun 22, 2021 at 02:39:42PM +0300, Leon Romanovsky wrote:
> 
> > diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
> > index 0eb40025075f..a76ef6a6bac5 100644
> > +++ b/drivers/infiniband/core/umem.c
> > @@ -51,11 +51,11 @@ static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int d
> >  	struct scatterlist *sg;
> >  	unsigned int i;
> >  
> > -	if (umem->nmap > 0)
> > -		ib_dma_unmap_sg(dev, umem->sg_head.sgl, umem->sg_nents,
> > -				DMA_BIDIRECTIONAL);
> > +	if (dirty)
> > +		ib_dma_unmap_sgtable_attrs(dev, &umem->sg_head,
> > +					   DMA_BIDIRECTIONAL, 0);
> >  
> > -	for_each_sg(umem->sg_head.sgl, sg, umem->sg_nents, i)
> > +	for_each_sgtable_dma_sg(&umem->sg_head, sg, i)
> >  		unpin_user_page_range_dirty_lock(sg_page(sg),
> >  			DIV_ROUND_UP(sg->length, PAGE_SIZE), make_dirty);
> 
> This isn't right, can't mix sg_page with a _dma_ API

Jason, why is that?

We use same pages that were passed to __sg_alloc_table_from_pages() in __ib_umem_get().

Thanks

> 
> Jason