On Tue, May 23, 2017 at 02:31:17PM +0530, Sricharan R wrote: > Hi Lorenzo, > > On 5/23/2017 2:22 PM, Lorenzo Pieralisi wrote: > > On Tue, May 23, 2017 at 02:26:10AM -0400, Nate Watterson wrote: > >> Hi Sricharan, > >> > >> On 4/10/2017 7:21 AM, Sricharan R wrote: > >>> This is an equivalent to the DT's handling of the iommu master's probe > >>> with deferred probing when the corrsponding iommu is not probed yet. > >>> The lack of a registered IOMMU can be caused by the lack of a driver for > >>> the IOMMU, the IOMMU device probe not having been performed yet, having > >>> been deferred, or having failed. > >>> > >>> The first case occurs when the firmware describes the bus master and > >>> IOMMU topology correctly but no device driver exists for the IOMMU yet > >>> or the device driver has not been compiled in. Return NULL, the caller > >>> will configure the device without an IOMMU. > >>> > >>> The second and third cases are handled by deferring the probe of the bus > >>> master device which will eventually get reprobed after the IOMMU. > >>> > >>> The last case is currently handled by deferring the probe of the bus > >>> master device as well. A mechanism to either configure the bus master > >>> device without an IOMMU or to fail the bus master device probe depending > >>> on whether the IOMMU is optional or mandatory would be a good > >>> enhancement. > >>> > >>> Tested-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx> > >>> Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx> > >>> [Lorenzo: Added fixes for dma_coherent_mask overflow, acpi_dma_configure > >>> called multiple times for same device] > >>> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> > >>> Signed-off-by: Sricharan R <sricharan@xxxxxxxxxxxxxx> > >>> --- > >>> drivers/acpi/arm64/iort.c | 33 ++++++++++++++++++++++++++++++++- > >>> drivers/acpi/scan.c | 11 ++++++++--- > >>> drivers/base/dma-mapping.c | 2 +- > >>> include/acpi/acpi_bus.h | 2 +- > >>> include/linux/acpi.h | 7 +++++-- > >>> 5 files changed, 47 insertions(+), 8 deletions(-) > >>> > >>> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c > >>> index 3dd9ec3..e323ece 100644 > >>> --- a/drivers/acpi/arm64/iort.c > >>> +++ b/drivers/acpi/arm64/iort.c > >>> @@ -543,6 +543,14 @@ static const struct iommu_ops *iort_iommu_xlate(struct device *dev, > >>> const struct iommu_ops *ops = NULL; > >>> int ret = -ENODEV; > >>> struct fwnode_handle *iort_fwnode; > >>> + struct iommu_fwspec *fwspec = dev->iommu_fwspec; > >>> + > >>> + /* > >>> + * If we already translated the fwspec there > >>> + * is nothing left to do, return the iommu_ops. > >>> + */ > >>> + if (fwspec && fwspec->ops) > >>> + return fwspec->ops; > >> > >> Is this logic strictly required? It breaks masters with multiple SIDs > >> as only the first SID is actually added to the master's fwspec. > > > > My bad, that's indeed a silly bug I introduced. Please let me know if the > > patch below fixes it, we will send it upstream shortly. > > > > oops, i think emails crossed. Please let me know if you are ok to add > this to the other fixes. No worries, yes I am ok thanks but please give Nate some time to report back to make sure the diff I sent actually fixes the problem. Apologies for the breakage. Lorenzo > > Regards, > Sricharan >
