On Wed, Nov 04, 2020 at 10:50:49AM +0100, Christoph Hellwig wrote:
> +int ib_dma_virt_map_sg(struct ib_device *dev, struct scatterlist *sg, int
> nents)
> +{
> + struct scatterlist *s;
> + int i;
> +
> + for_each_sg(sg, s, nents, i) {
> + sg_dma_address(s) = (uintptr_t)sg_virt(s);
> + sg_dma_len(s) = s->length;
Hmm.. There is nothing ensuring the page is mapped here for this
sg_virt(). Before maybe some of the kconfig stuff prevented highmem
systems indirectly, I wonder if we should add something more direct to
exclude highmem for these drivers?
Sigh. I think the proper fix is to replace addr/length with a
scatterlist pointer in the struct ib_sge, then have SW drivers
directly use the page pointer properly.
Then just delete this stuff, all drivers need is a noop dmaops
Looks a lot hard though, so we should probably go ahead with this.
Jason
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