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.
Regards,
Sricharan
> Lorenzo
>
> -- >8 --
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index c5fecf9..e326f2a 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -666,14 +666,6 @@ static const struct iommu_ops *iort_iommu_xlate(struct device *dev,
> int ret = -ENODEV;
> struct fwnode_handle *iort_fwnode;
>
> - /*
> - * If we already translated the fwspec there
> - * is nothing left to do, return the iommu_ops.
> - */
> - ops = iort_fwspec_iommu_ops(dev->iommu_fwspec);
> - if (ops)
> - return ops;
> -
> if (node) {
> iort_fwnode = iort_get_fwnode(node);
> if (!iort_fwnode)
> @@ -735,6 +727,14 @@ const struct iommu_ops *iort_iommu_configure(struct device *dev)
> u32 streamid = 0;
> int err;
>
> + /*
> + * If we already translated the fwspec there
> + * is nothing left to do, return the iommu_ops.
> + */
> + ops = iort_fwspec_iommu_ops(dev->iommu_fwspec);
> + if (ops)
> + return ops;
> +
> if (dev_is_pci(dev)) {
> struct pci_bus *bus = to_pci_dev(dev)->bus;
> u32 rid;
>
>
--
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