On Wed, Apr 24, 2019 at 03:18:59PM +0100, Tom Murphy via iommu wrote: > check if there is a not-present cache present and flush it if there is. > > Signed-off-by: Tom Murphy <tmur...@arista.com> > --- > drivers/iommu/amd_iommu.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c > index f7cdd2ab7f11..8ef43224aae0 100644 > --- a/drivers/iommu/amd_iommu.c > +++ b/drivers/iommu/amd_iommu.c > @@ -1636,6 +1636,12 @@ static int iommu_map_page(struct protection_domain > *dom, > pte[i] = __pte; > > update_domain(dom); > + if (!dom->updated) { > + if (unlikely(amd_iommu_np_cache)) { > + domain_flush_pages(dom, bus_addr, page_size); > + domain_flush_complete(dom); > + } > + }
The two conditions can go into one if statement to make this a little more clear. And I'd really like to understand the unlikely - amd_iommu_np_cache is set based on a hardware capability, so it seems rather odd to mark it unlikely. Dynamic branch prediction really should do the right thing here usually. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu