On Wed, Feb 20, 2019 at 04:55:39PM +0200, Leon Romanovsky wrote:
> On Tue, Feb 19, 2019 at 08:57:42AM -0600, Shiraz Saleem wrote:
> > This helper iterates over the SG list and returns contiguous
> > memory blocks aligned to a HW supported page size.
> > The implementation is intended to work for HW that support
> > single page sizes or mixed page sizes in an MR. Drivers
> > can use this helper to retreive the DMA addresses aligned
> > to their best supported page size.
> >
> > Suggested-by: Jason Gunthorpe <jgg@xxxxxxxx>
> > Reviewed-by: Michael J. Ruhl <michael.j.ruhl@xxxxxxxxx>
> > Signed-off-by: Shiraz Saleem <shiraz.saleem@xxxxxxxxx>
> > ---
> > drivers/infiniband/core/umem.c | 90 ++++++++++++++++++++++++++++++++++++++++++
> > include/rdma/ib_umem.h | 23 +++++++++++
> > 2 files changed, 113 insertions(+)
> >
> > diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
> > index d3b572e..8c3ec1b 100644
> > --- a/drivers/infiniband/core/umem.c
> > +++ b/drivers/infiniband/core/umem.c
> > @@ -214,6 +214,96 @@ unsigned long ib_umem_find_single_pg_size(struct ib_umem *umem,
> > }
> > EXPORT_SYMBOL(ib_umem_find_single_pg_size);
> >
> > +static unsigned int ib_umem_find_mixed_pg_bit(struct scatterlist *sgl_head,
> > + struct sg_phys_iter *sg_phys_iter)
> > +{
> > + unsigned long dma_addr_start, dma_addr_end;
> > +
> > + dma_addr_start = sg_dma_address(sg_phys_iter->sg);
> > + dma_addr_end = sg_dma_address(sg_phys_iter->sg) +
> > + sg_dma_len(sg_phys_iter->sg);
> > +
> > + if (sg_phys_iter->sg == sgl_head)
> > + return ib_umem_find_pg_bit(dma_addr_end,
> > + sg_phys_iter->supported_pgsz);
> > + else if (sg_is_last(sg_phys_iter->sg))
> > + return ib_umem_find_pg_bit(dma_addr_start,
> > + sg_phys_iter->supported_pgsz);
> > + else
> > + return ib_umem_find_pg_bit(sg_phys_iter->phyaddr,
> > + sg_phys_iter->supported_pgsz);
>
> It is very confusing, at least for me, the usage of first argument of
> ib_umem_find_pg_bit(). In previous patch, you wrote that it is
> phys address, but here you are mixing physical and DMA addresses.
>
The helper ib_umem_find_pg_bit() really is generic to work with any addr. I should however, not tie
it to any type in the description.
Shiraz
