On 04/04/17 11:18, Sricharan R wrote: > From: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> > > The IOMMU probe deferral implementation requires a mechanism to detect > if drivers for SMMU components are built-in in the kernel to detect > whether IOMMU configuration for a given device should be deferred (ie > SMMU drivers present but still not probed) or not (drivers not present). > > Add a simple function to IORT to detect if SMMU drivers for SMMU > components managed by IORT are built-in in the kernel. Ah, if only DT could be this neat and tidy :D Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx> > Tested-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx> > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> > Cc: Robin Murphy <robin.murphy@xxxxxxx> > Cc: Sricharan R <sricharan@xxxxxxxxxxxxxx> > --- > drivers/acpi/arm64/iort.c | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c > index 4a5bb96..3dd9ec3 100644 > --- a/drivers/acpi/arm64/iort.c > +++ b/drivers/acpi/arm64/iort.c > @@ -523,6 +523,19 @@ static int arm_smmu_iort_xlate(struct device *dev, u32 streamid, > return ret; > } > > +static inline bool iort_iommu_driver_enabled(u8 type) > +{ > + switch (type) { > + case ACPI_IORT_NODE_SMMU_V3: > + return IS_BUILTIN(CONFIG_ARM_SMMU_V3); > + case ACPI_IORT_NODE_SMMU: > + return IS_BUILTIN(CONFIG_ARM_SMMU); > + default: > + pr_warn("IORT node type %u does not describe an SMMU\n", type); > + return false; > + } > +} > + > static const struct iommu_ops *iort_iommu_xlate(struct device *dev, > struct acpi_iort_node *node, > u32 streamid) >