On 19/07/17 10:33, Anup Patel wrote: > The ARM SMMUv1 and SMMUv2 support bypassing transactions for > which domain is not configured. The patch adds corresponding > IOMMU capability to advertise this fact. > > Signed-off-by: Anup Patel <anup.patel@xxxxxxxxxxxx> > --- > drivers/iommu/arm-smmu.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c > index bc89b4d..08a9020 100644 > --- a/drivers/iommu/arm-smmu.c > +++ b/drivers/iommu/arm-smmu.c > @@ -1483,6 +1483,8 @@ static bool arm_smmu_capable(enum iommu_cap cap) > return true; > case IOMMU_CAP_NOEXEC: > return true; > + case IOMMU_CAP_BYPASS: > + return true; Except when it isn't, of course. Beware that what we'd like to do in the long term is flip the polarity of disable_bypass, because there isn't generally a good reason for Non-Secure DMA to be happening behind Linux's back. Robin. > default: > return false; > } >
