2022-05-16 13:59:07

by Mikko Perttunen

Subject: Re: [PATCH v5 5/9] iommu/arm-smmu: Attach to host1x context device bus

On 5/16/22 13:07, Will Deacon wrote:
> On Mon, May 16, 2022 at 11:52:54AM +0300, [email protected] wrote:
>> From: Mikko Perttunen <[email protected]>
>>
>> Set itself as the IOMMU for the host1x context device bus, containing
>> "dummy" devices used for Host1x context isolation.
>>
>> Signed-off-by: Mikko Perttunen <[email protected]>
>> ---
>> drivers/iommu/arm/arm-smmu/arm-smmu.c | 13 +++++++++++++
>> 1 file changed, 13 insertions(+)
>>
>> diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
>> index 568cce590ccc..9ff54eaecf81 100644
>> --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
>> +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
>> @@ -39,6 +39,7 @@
>>
>> #include <linux/amba/bus.h>
>> #include <linux/fsl/mc.h>
>> +#include <linux/host1x_context_bus.h>
>>
>> #include "arm-smmu.h"
>>
>> @@ -2053,8 +2054,20 @@ static int arm_smmu_bus_init(struct iommu_ops *ops)
>> goto err_reset_pci_ops;
>> }
>> #endif
>> +#ifdef CONFIG_TEGRA_HOST1X_CONTEXT_BUS
>> + if (!iommu_present(&host1x_context_device_bus_type)) {
>> + err = bus_set_iommu(&host1x_context_device_bus_type, ops);
>> + if (err)
>> + goto err_reset_fsl_mc_ops;
>> + }
>> +#endif
>> +
>> return 0;
>>
>> +err_reset_fsl_mc_ops: __maybe_unused;
>> +#ifdef CONFIG_FSL_MC_BUS
>> + bus_set_iommu(&fsl_mc_bus_type, NULL);
>> +#endif
>
> bus_set_iommu() is going away:
>
> https://lore.kernel.org/r/[email protected]
>
> Will

Thanks for the heads-up. Robin had pointed out that this work was
ongoing but I hadn't seen the patches yet. I'll look into it.

Mikko

>>

2022-05-16 19:40:14

by Robin Murphy

Subject: Re: [PATCH v5 5/9] iommu/arm-smmu: Attach to host1x context device bus

On 2022-05-16 11:13, Mikko Perttunen wrote:
> On 5/16/22 13:07, Will Deacon wrote:
>> On Mon, May 16, 2022 at 11:52:54AM +0300, [email protected] wrote:
>>> From: Mikko Perttunen <[email protected]>
>>>
>>> Set itself as the IOMMU for the host1x context device bus, containing
>>> "dummy" devices used for Host1x context isolation.
>>>
>>> Signed-off-by: Mikko Perttunen <[email protected]>
>>> ---
>>>   drivers/iommu/arm/arm-smmu/arm-smmu.c | 13 +++++++++++++
>>>   1 file changed, 13 insertions(+)
>>>
>>> diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c
>>> b/drivers/iommu/arm/arm-smmu/arm-smmu.c
>>> index 568cce590ccc..9ff54eaecf81 100644
>>> --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
>>> +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
>>> @@ -39,6 +39,7 @@
>>>   #include <linux/amba/bus.h>
>>>   #include <linux/fsl/mc.h>
>>> +#include <linux/host1x_context_bus.h>
>>>   #include "arm-smmu.h"
>>> @@ -2053,8 +2054,20 @@ static int arm_smmu_bus_init(struct iommu_ops
>>> *ops)
>>>               goto err_reset_pci_ops;
>>>       }
>>>   #endif
>>> +#ifdef CONFIG_TEGRA_HOST1X_CONTEXT_BUS
>>> +    if (!iommu_present(&host1x_context_device_bus_type)) {
>>> +        err = bus_set_iommu(&host1x_context_device_bus_type, ops);
>>> +        if (err)
>>> +            goto err_reset_fsl_mc_ops;
>>> +    }
>>> +#endif
>>> +
>>>       return 0;
>>> +err_reset_fsl_mc_ops: __maybe_unused;
>>> +#ifdef CONFIG_FSL_MC_BUS
>>> +    bus_set_iommu(&fsl_mc_bus_type, NULL);
>>> +#endif
>>
>> bus_set_iommu() is going away:
>>
>> https://lore.kernel.org/r/[email protected]
>>
>> Will
>
> Thanks for the heads-up. Robin had pointed out that this work was
> ongoing but I hadn't seen the patches yet. I'll look into it.

Although that *is* currently blocked on the mystery intel-iommu problem
that I can't reproduce... If this series is ready to land right now for
5.19 then in principle that might be the easiest option overall.
Hopefully at least patch #2 could sneak in so that the compile-time
dependencies are ready for me to roll up host1x into the next rebase of
"iommu: Always register bus notifiers".

Cheers,
Robin.