Re: [PATCH v8 6/6] iommu/tegra-smmu: Add pagetable mappings to debugfs

From: Dmitry Osipenko
Date: Thu Dec 09 2021 - 14:44:30 EST


09.12.2021 22:24, Nicolin Chen пишет:
> On Thu, Dec 09, 2021 at 05:49:09PM +0300, Dmitry Osipenko wrote:
>> External email: Use caution opening links or attachments
>>
>>
>> 09.12.2021 10:38, Nicolin Chen пишет:
>>> +static unsigned long pd_pt_index_iova(unsigned int pd_index, unsigned int pt_index)
>>> +{
>>> + return (pd_index & (SMMU_NUM_PDE - 1)) << SMMU_PDE_SHIFT |
>>> + (pt_index & (SMMU_NUM_PTE - 1)) << SMMU_PTE_SHIFT;
>>> +}
>>
>> I'd change the return type to u32 here, for consistency.
>
> The whole file defines iova using "unsigned long", which I see
> as the consistency... If we change it to u32, it'd be probably
> necessary to change all iova types to u32 too... So I'd rather
> keep it "unsigned long" here. If you see a big necessity to do
> that, an additional patch would be nicer IMHO.
>

In general IOVA is "unsigned long", of course. But in case of Tegra
SMMU, we know that is always u32.

Alright, I see now that there are other places in the driver code that
use "unsigned long", so need to change it in this patch.