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Subject: Re: [PATCH 5/5] iommu/tegra-smmu: Add pagetable mappings to debugfs
From:   Dmitry Osipenko <digetx@gmail.com>
To:     Nicolin Chen <nicoleotsuka@gmail.com>, thierry.reding@gmail.com,
        joro@8bytes.org, krzk@kernel.org
Cc:     linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org,
        iommu@lists.linux-foundation.org, jonathanh@nvidia.com
References: <20200926080719.6822-1-nicoleotsuka@gmail.com>
 <20200926080719.6822-6-nicoleotsuka@gmail.com>
 <0451e362-30eb-2ba2-33f1-e9ab3972cada@gmail.com>
Message-ID: <a321fc27-54ba-9ba5-7121-4598a7f94795@gmail.com>
Date:   Sun, 27 Sep 2020 00:37:56 +0300
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27.09.2020 00:24, Dmitry Osipenko пишет:
> 26.09.2020 11:07, Nicolin Chen пишет:
> ...
>> +	for (pd_index = 0; pd_index < SMMU_NUM_PDE; pd_index++) {
>> +		struct page *pt;
>> +		u32 *addr;
>> +
>> +		if (!as->count[pd_index] || !pd[pd_index])
>> +			continue;
> 
> I guess the idea of this patch is to print out the hardware state, isn't
> it? Hence the as->count shouldn't be checked here.

Perhaps also will be good to check whether the state of
!as->count[pd_index] matches state of !pd[pd_index].

WARN_ON_ONCE(!as->count[pd_index] ^ !pd[pd_index])