Re: [PATCH 26/34] AMD IOMMU: add mapping functions for scatter gather lists

[Joerg Roedel <joerg.roedel@amd.com>]

On Mon, Jun 30, 2008 at 12:07:16AM +0900, FUJITA Tomonori wrote:
> On Thu, 26 Jun 2008 21:28:02 +0200
> Joerg Roedel <joerg.roedel@amd.com> wrote:
> 
> > This patch adds the dma_ops functions for mapping and unmapping scatter gather
> > lists.
> > 
> > Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
> > ---
> >  arch/x86/kernel/amd_iommu.c |   98 +++++++++++++++++++++++++++++++++++++++++++
> >  1 files changed, 98 insertions(+), 0 deletions(-)
> > 
> > diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
> > index b4079f6..f4747fe 100644
> > --- a/arch/x86/kernel/amd_iommu.c
> > +++ b/arch/x86/kernel/amd_iommu.c
> > @@ -700,3 +700,101 @@ static void unmap_single(struct device *dev, dma_addr_t dma_addr,
> >  	spin_unlock_irqrestore(&domain->lock, flags);
> >  }
> >  
> > +static int map_sg_no_iommu(struct device *dev, struct scatterlist *sglist,
> > +			   int nelems, int dir)
> > +{
> > +	struct scatterlist *s;
> > +	int i;
> > +
> > +	for_each_sg(sglist, s, nelems, i) {
> > +		s->dma_address = (dma_addr_t)sg_phys(s);
> > +		s->dma_length  = s->length;
> > +	}
> > +
> > +	return nelems;
> > +}
> > +
> > +static int map_sg(struct device *dev, struct scatterlist *sglist,
> > +		  int nelems, int dir)
> > +{
> > +	unsigned long flags;
> > +	struct amd_iommu *iommu;
> > +	struct protection_domain *domain;
> > +	u16 devid;
> > +	int i;
> > +	struct scatterlist *s;
> > +	phys_addr_t paddr;
> > +	int mapped_elems = 0;
> > +
> > +	get_device_resources(dev, &iommu, &domain, &devid);
> > +
> > +	if (!iommu || !domain)
> > +		return map_sg_no_iommu(dev, sglist, nelems, dir);
> 
> VT-d put a pointer in struct dev_archdata to store IOMMU info per
> device. Is is useful for you too?

Hmm yes. Thank you for that hint. I can save at least one of my arrays
with that method.

Joerg


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