Re: [PATCH v1 1/3] iommu/tegra-smmu: Fix invalid ASID bits on Tegra30/114

[Dmitry Osipenko]

03.04.2019 11:41, Thierry Reding ÐÐÑÐÑ:
> On Thu, Mar 07, 2019 at 01:50:07AM +0300, Dmitry Osipenko wrote:
>> Both Tegra30 and Tegra114 have 4 ASID's and the corresponding bitfield of
>> the TLB_FLUSH register differs from later Tegra generations that have 128
>> ASID's.
>>
>> In a result the PTE's are now flushed correctly from TLB and this fixes
>> problems with graphics (randomly failing tests) on Tegra30.
>>
>> Cc: stable <stable@xxxxxxxxxxxxxxx>
>> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
>> ---
>>  drivers/iommu/tegra-smmu.c | 25 ++++++++++++++++++-------
>>  1 file changed, 18 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
>> index 5182c7d6171e..8d30653cd13a 100644
>> --- a/drivers/iommu/tegra-smmu.c
>> +++ b/drivers/iommu/tegra-smmu.c
>> @@ -102,7 +102,6 @@ static inline u32 smmu_readl(struct tegra_smmu *smmu, unsigned long offset)
>>  #define  SMMU_TLB_FLUSH_VA_MATCH_ALL     (0 << 0)
>>  #define  SMMU_TLB_FLUSH_VA_MATCH_SECTION (2 << 0)
>>  #define  SMMU_TLB_FLUSH_VA_MATCH_GROUP   (3 << 0)
>> -#define  SMMU_TLB_FLUSH_ASID(x)          (((x) & 0x7f) << 24)
> 
> Given that the same operation is repeated three times below, it might
> have been worth to fold the conditional into the macro. That'd require
> the macro to take an smmu parameter, but would otherwise leave the
> individual instances shorter.

I had that variant initially and the result felt more clumsy to me.

> But either way, the fix is good, so:
> 
> Acked-by: Thierry Reding <treding@xxxxxxxxxx>
> 

Thanks